Donate Help Contact The AHA Sign In Home
American Heart Association
Arteriosclerosis, Thrombosis, and Vascular Biology
Search: search_blue_button Advanced Search
Arteriosclerosis, Thrombosis, and Vascular Biology. 2001;21:1104-1117
doi: 10.1161/hq0701.093685
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pepper, M. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pepper, M. S.
Related Collections
Right arrow Angiogenesis
Right arrow Growth factors/cytokines
Right arrow Fibrinogen/fibrin
Right arrow Other Vascular biology
Right arrow Other Research
(Arteriosclerosis, Thrombosis, and Vascular Biology. 2001;21:1104.)
© 2001 American Heart Association, Inc.


Brief Review

Role of the Matrix Metalloproteinase and Plasminogen Activator–Plasmin Systems in Angiogenesis

Michael S. Pepper

From the Department of Morphology, University Medical Center, Geneva, Switzerland.

Correspondence to Dr M.S. Pepper, Département de Morphologie, Centre Médical Universitaire, 1, rue Michel-Servet, 1211 Genève 4, Switzerland. E-mail: michael.pepper{at}medecine.unige.ch


*    Abstract
up arrowTop
*Abstract
down arrowIntroduction
down arrowRole of the MMP...
down arrowRequirement for Gelatinases and...
down arrowMMP Requirement for Fibrinolysis...
down arrowRole of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
Abstract—Extracellular proteolysis is an absolute requirement for new blood vessel formation (angiogenesis). This review examines the role of the matrix metalloproteinase (MMP) and plasminogen activator (PA)–plasmin systems during angiogenesis. Specifically, a role for gelatinases (MMP-2, MMP-9), membrane-type 1 MMP (MMP-14), the urokinase-type PA receptor, and PA inhibitor 1 has been clearly defined in a number of model systems. The MMP and PA-plasmin systems have also been implicated in experimental vascular tumor formation, and their role during this process will be examined. Antiproteolysis, particularly in the context of angiogenesis, has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization.


Key Words: extracellular matrix • endothelium • metalloproteinase • plasminogen • cancer


*    Introduction
up arrowTop
up arrowAbstract
*Introduction
down arrowRole of the MMP...
down arrowRequirement for Gelatinases and...
down arrowMMP Requirement for Fibrinolysis...
down arrowRole of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
It is firmly established that angiogenesis is an absolute requirement for the growth of normal and neoplastic tissues.1 Many biological processes, including angiogenesis, depend on tightly controlled interactions between cells and the extracellular matrix (ECM). These interactions are mediated by (1) integral membrane proteins, including integrins, which provide a link between the ECM and the cytoskeleton, and (2) extracellular proteinases and their inhibitors, which mediate focal degradation of components of the ECM, some of which (eg, the fibrillar collagens) are highly resistant to broad-spectrum proteases. Most of the relevant extracellular proteolytic enzymes belong to one of two families: the serine proteases, in particular, the plasminogen activator (PA)–plasmin system, and the matrix metalloproteinases (MMPs).2 3 4

Like most other biological processes, angiogenesis is the result of subtle and often complex interactions between regulatory and effector molecules. To facilitate its analysis, it is useful to divide angiogenesis into a phase of activation (sprouting) and a phase of resolution. The phase of activation encompasses (1) increased vascular permeability and extravascular fibrin deposition; (2) vessel wall disassembly; (3) basement membrane degradation; (4) cell migration and ECM invasion; (5) endothelial cell proliferation; and (6) capillary lumen formation. The phase of resolution includes (1) inhibition of endothelial cell proliferation; (2) cessation of cell migration; (3) basement membrane reconstitution; (4) junctional complex maturation; and (5) vessel wall assembly, including recruitment and differentiation of smooth muscle cells and pericytes. Implicit in the definition of the resolution phase is the establishment of blood flow in the newly formed vessel.1 Extracellular proteolysis has been implicated in many of these processes, including basement membrane degradation, cell migration/ECM invasion, and capillary lumen formation (the TableDown).5


View this table:
[in this window]
[in a new window]
 
Table 1. Extracellular Proteolysis and Angiogenesis

The classic descriptions by Clark and Clark in 19396 of new blood vessel formation in transparent chambers in the rabbit ear clearly demonstrate the production of fibrinolytic activity by growing capillary sprouts: "As new blood vessels advanced ... the fibrin outside them dissolved, leaving a clear space surrounding the new vessels which was filled at times with fluid but more commonly with a transparent gelatinous substance containing occasional blood cells, macrophages and fibroblasts. Although long, tapering, solid tips might be seen extending directly into the fibrin, which was still present beyond the advancing capillary network, the new capillaries, and even capillaries in which the circulation had not yet started, but which possessed a lumen and a rouleaux of erythrocytes, were all surrounded by a characteristic clear space from which fibrin had disappeared." A similar phenomenon of fibrin dissolution was described in studies of acute inflammation induced by subcutaneous implantation of a fibrin clot in the rat.7 Capillary sprouts were associated with "empty zones" in the fibrin clot, which was indicative of fibrin degradation. Fibrinolytic activity decreased progressively in the later stages of the inflammatory process as the fibrin clot was replaced by connective tissue. These two articles were among the first to describe the presence of extracellular proteolytic activity in the endothelial pericellular environment during angiogenesis. They also highlighted the existence of a temporal sequence of matrix dissolution and assembly, in which fibrin provides a temporary matrix scaffold for migrating endothelial cells, which with time is replaced by a more mature collagenous matrix.

One of the earliest events in the activation (sprouting) phase of angiogenesis is basement membrane degradation, and that this process may be mediated by matrix metalloproteinases (MMPs) was demonstrated almost 20 years ago.8 These authors described the presence of type IV and V collagenolytic activity produced by bovine endothelial cells induced to migrate down a chemotactic gradient. No collagenolytic activity was observed in the absence of the gradient (even in the presence of the chemotactic agent), illustrating that enzyme activity was associated with the migration process.

Considerable progress has since been made in understanding the mechanisms of angiogenesis. Thus, angiogenesis is controlled by the net balance between molecules that have positive and negative regulatory activity.1 With the exception of angiogenesis that occurs in response to tissue injury or in female reproductive organs, endothelial cell turnover in the healthy, adult organism is very low. The maintenance of endothelial quiescence is thought to be due to the presence of endogenous negative regulators, because positive regulators are frequently detected in adult tissues in which there is apparently no angiogenesis. The converse is also true, namely, that positive and negative regulators often coexist in tissues in which endothelial cell turnover is increased. This has led to the notion of the "angiogenic switch," in which endothelial activation status is determined by a balance between positive and negative regulators: in activated (angiogenic) endothelium, positive regulators predominate, whereas endothelial quiescence is achieved and maintained by the dominance of negative regulators. The switch involves either the induction of a positive regulator and/or the loss of a negative regulator.9 10 Used initially in the context of tumor progression to describe the passage from the prevascular to the vascular phase, the notion of the switch can also be applied to developmental, physiological, and pathological angiogenesis.

Positive regulators of angiogenesis include, but are not limited to, the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) families of cytokines and their tyrosine kinase receptors.11 12 13 14 Interestingly, it has been observed that VEGF and basic FGF (bFGF, or FGF-2) induce a synergistic angiogenic response, both in vitro15 16 and in vivo.17 18 A number of endogenous negative regulators have been described, including inhibitors of extracellular proteinases, thrombospondins 1 and 2, and bioactive fragments of the ECM and other molecules (see below).1 19 20 21

The notion of the "balance" applied to positive and negative regulators of angiogenesis can also be applied to extracellular proteolysis. The resulting notion of the "proteolytic balance,"5 22 which highlights the importance of a precise protease-antiprotease equilibrium, has become one of the cornerstones on which our understanding of the molecular mechanisms of angiogenesis is based. Thus, although it has consistently been observed that endothelial cell migration and invasion are associated with increased proteolysis, protease inhibitors play an important albeit permissive role during angiogenesis by preserving matrix integrity. For example, in wound healing and inflammatory skin lesions, protease inhibitors have been localized to stromal cells surrounding vessels in regions of active vascular proliferation, where they may serve to prevent uncontrolled matrix destruction.23 Excessive proteolysis is incompatible with normal angiogenesis, because it results either in destruction of the matrix scaffold that is required for invasion or in the formation of aberrant vascular structures.24 In the absence of sufficient proteolysis, on the other hand, invasion and lumen formation are inhibited.25

Another important notion is that of spatial restriction of extracellular proteolysis. The objective of spatial restriction is to amplify cell surface activity, while at the same time limiting proteolysis to the immediate pericellular environment. This objective is achieved through the local production of protease inhibitors as outlined above, as well as through the assembly of components of one or more protease systems on the cell surface, which brings the enzymes into close proximity to one another. The result is a highly efficient proteolytic cascade on the cell surface, which increases the efficiency of invasion without destroying the matrix scaffold required for invasion (for example, see Mazzieri et al26 ).

In addition to its requirement for matrix invasion and capillary morphogenesis, extracellular proteolysis has been implicated in the regulation of cytokine activity (the TableUp). Examples include activation of latent transforming growth factor-ß (TGF-ß),27 release of matrix-bound bFGF and VEGF,27 28 release of membrane-anchored tumor necrosis factor-{alpha} (TNF-{alpha}),29 and inactivation of monocyte chemoattractant protein 3, with the resultant generation of a chemokine antagonist.30

Finally, extracellular proteolysis has been implicated in the generation of proteolytic fragments of the ECM and other molecules, a number of which have been reported to have angioregulatory activity, either positive or negative (the TableUp).31 Much attention has been focused on angiostatin and endostatin, which are negative regulators derived from plasminogen and collagen XVIII, respectively.32 33 Fragments of collagen IV, which are also negative regulators, include arresten, from the {alpha}1 chain,34 canstatin, from the {alpha}2 chain,35 and tumstatin, from the {alpha}3 chain.36 37 Other ECM proteins from which fragments with angioregulatory activity have been derived include thrombospondin (inhibitory), hyaluronan (stimulatory), SPARC (secreted protein, acidic, rich in cysteine; stimulatory and inhibitory), and collagen XV/restin (inhibitory).38 Non-ECM molecules from which fragments with angioinhibitory activity have been derived include prolactin, platelet factor 4, MMP-2 (PEX; see below), calreticulin (vasostatin),39 and high-molecular-weight kininogen domain 5 (kininostatin).40 Finally, a cleaved form of antithrombin has also been shown to have antiangiogenic activity.41 It should be pointed out, however, that despite a large amount of information that has accumulated on their antiangiogenic activity, a degree of caution is still required when interpreting the effects of many of these molecules, including the mechanisms and precise molecular nature of their biological activity.


*    Role of the MMP System in Angiogenesis
up arrowTop
up arrowAbstract
up arrowIntroduction
*Role of the MMP...
down arrowRequirement for Gelatinases and...
down arrowMMP Requirement for Fibrinolysis...
down arrowRole of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
MMPs are a family of zinc-dependent enzymes that can be divided into 2 structurally distinct groups, namely, secreted MMPs and membrane-type MMPs (MT-MMPs). Secreted MMPs include (but are not limited to) collagenases (interstitial collagenase, or MMP-1; neutrophil collagenase, or MMP-8; and rodent interstitial collagenase, or MMP-13), gelatinases (gelatinase A, or MMP-2; gelatinase B, or MMP-9), stromelysins (stromelysin-1, or MMP-3; stromelysin-2, or MMP-10; stromelysin-3, or MMP-11), and other MMPs (matrilysin, or MMP-7; metalloelastase, or MMP-12). The catalytic activity of secreted MMPs is tightly regulated. They are secreted as inactive proenzymes (zymogens), with activation occurring in the extracellular compartment. In the case of some MMPs (eg, MMP-2), this occurs in association with the plasma membrane.42 43

At least 5 genetically distinct MT-MMPs have been identified (MMP-14, -15, -16, -17, -21). With the exception of MMP-17 (which is glycosyl-phosphatidyl inositol (GPI)-anchored), these enzymes are single-pass type I membrane proteins with an extracellular N-terminus and a short, cytoplasmic C-terminal domain. MT-MMPs are activated intracellularly in the secretory pathway by furinlike enzymes. By virtue of its localization and activity, MT1-MMP is endowed with 2 characteristics important for cell migration: association with the plasma membrane, which focuses matrix digestion close to the cell surface, and the capacity to catalytically activate the precursor of another extracellular protease, namely MMP-2, which allows for amplification of the degradative process. MT1-MMP also has direct activity against a number of ECM proteins, including gelatin, fibronectin, vitronectin, fibrillar collagens, and aggrecan.44 45

In addition to zymogen activation, MMP activity is subject to regulation by tissue inhibitors of metalloproteases (TIMPs), four of which have thus far been described. TIMPs form a 1:1 stoichiometric complex with all activated MMPs, with which they become covalently linked. TIMP-1 also binds pro–MMP-9. TIMP-2 and -4 also bind pro–MMP-2. TIMP-2 and -3 are effective inhibitors of MT-MMPs, whereas TIMP-3 is a good inhibitor of TNF-{alpha}–converting enzyme. TIMP-3 is deposited in the ECM and is notoriously difficult to extract from tissues.46

The functional interaction between the two classes of MMPs has been the subject of intense research over the past few years. For example, MT1-MMP is a cellular receptor for and activator of pro–MMP-2, with which it forms a trimolecular complex on the cell surface with TIMP-2.44 45 The importance of MMP-2 and MT1-MMP during angiogenesis has been reviewed.47 MMP-2, MT1-MMP, TIMP-2, and integrin {alpha}vß3 have been colocalized in caveolae in the basolateral compartment of human endothelial cells.48 In contrast, MMP-9 and TIMP-1 are uniformly distributed on the cell surface and are concentrated in the Golgi region. Interestingly, it has been demonstrated that TIMP-2 and -3 derived from perivascular cells (pericytes and smooth muscle cells) are capable of inhibiting the activation of MMP-2 by MT1-MMP in endothelial cells.49 This interplay may be important during the resolution phase of angiogenesis and for the maintenance of endothelial quiescence.

With regard to localization studies, basal levels of expression of MMPs and TIMPs are absent or weakly positive in endothelial cells of normal tissues. However, these molecules are upregulated in endothelial cells (and in some instances, in pericytes) in a variety of physiological and pathological settings. Examples in which MMPs and TIMPs have been detected in endothelial cells include embryogenesis (MMP-1, -2), wound healing (MMP-2), endometrial blood vessels during the menstrual cycle (MMP-2, -3, -9; TIMP-1, -2), placental microvessels (MMP-2, -9; TIMP-1), rheumatoid arthritis (MMP-9), and a variety of tumors, including breast (MMP-2), endometrial (MMP-2, -9), hepatocellular (MMP-2, TIMP-2), colorectal (MMP-7), pancreatic (MMP-7), gastric (MMP-7), renal (MMP-7), and lung (MMP-7) carcinomas, as well as various brain tumors (MMP-2, -9, -14).50 51 52 53 54 55 56 57 58 59 60 61

Cultured endothelial cells have been shown to express MMP-1, -2, -3, -9, and -14 and TIMP-1 and -2.62 Studies on the regulation of MMPs and TIMPs in endothelial cells by angiogenic cytokines have revealed a variable response that is in part cell-type dependent. Thus, VEGF increased MMP-2 and MT-1 MMP, had no effect on MMP-1, and decreased TIMP-1 and -2 in human dermal microvascular endothelial cells.63 64 VEGF increased MMP-1, MMP-2, and TIMP-1 in human umbilical vein endothelial cells, and this change was accompanied by increased activation of MMP-2.65 66 bFGF induced MMP-1 in human omentum–derived67 or dermal68 microvascular endothelial cells. As a rule, the magnitude of the increase in MMP gene expression in response to angiogenic cytokines is significantly less than the increase seen with components of the PA-plasmin system (Figure 1ADown). Furthermore, expression of naturally occurring inhibitors of the MMP and PA-plasmin systems are not necessarily coordinately regulated: in response to TGF-ß1, plasminogen activator inhibitor 1 (PAI-1) is increased whereas TIMP-1 is decreased (Figures 1BDown and 1CDown). In addition to regulation by angiogenic cytokines, endothelial cell MMP-2 and MT1-MMP expression is markedly increased when endothelial cells are cultured in suspension in a 3-dimensional collagen gel compared with monolayer (2-dimensional) cultures,69 which in turn results in a 15-fold increase in MMP-2 activity. The collagen-dependent increase in MT1-MMP is mediated by the transcription factor Egr-1,70 whereas the increase in MMP-2 activation appears to require integrin {alpha}2ß1.71 Changes in Arg-Gly-Asp–dependent integrin clustering and cell shape have also been shown to alter MMP-2 activation in endothelial cells.72 Finally, MMPs -2 and -9 have been found to colocalize with ß1 integrin in focal contacts.73



View larger version (64K):
[in this window]
[in a new window]
 
Figure 1. Regulation of protease and inhibitor gene expression in bovine microvascular endothelial (BME) cells. (A) Confluent monolayers of BME cells were exposed to bFGF at the indicated concentrations for 15 hours. Total cellular RNA (5 µg/lane) was analyzed by Northern blotting. Replicate filters were probed with 32P-labeled bovine uPA, bovine uPAR, human MMP-2, and human MT1-MMP cRNA probes. Filters were stained with methylene blue to reveal 28S and 18S ribosomal RNAs. (B) Confluent monolayers of BME cells were exposed to TGF-ß1 at the indicated concentrations for 12 hours. Total cellular RNA (5 µg/lane) was analyzed by Northern blotting. Replicate filters were probed with 32P-labeled bovine TIMP-1 and PAI-1 cRNA probes. Filters were stained with methylene blue to reveal 28S and 18S ribosomal RNAs. (C) Confluent monolayers of BME cells were exposed to TGF-ß1 for the times indicated. Total cellular RNA (5 µg/lane) was analyzed by Northern blotting. Replicate filters were probed with 32P-labeled bovine TIMP-1 and PAI-1 cRNA probes. Filters were stained with methylene blue to reveal 28S and 18S ribosomal RNAs. (PAI-1 Northern blots in Figures 1BUp and 1CUp are from Mandriotta and Pepper169 [J Cell Sci. 1997;110:2293-2302.] and are reproduced with permission from the Company of Biologists Ltd.)

That MMPs are required for angiogenesis has been firmly established.62 74 75 76 Support for this notion has come mainly from studies in which angiogenesis, or various components thereof, could be inhibited by naturally occurring or synthetic MMP inhibitors. Most studies have addressed the activation (sprouting) phase of angiogenesis. For example, increased expression of TIMPs -1 and -2 inhibited tumor-associated angiogenesis, which in the case of TIMP-2 was associated with a marked reduction in expression of tumor-derived VEGF.77 78 Only recently has the requirement for inhibition of MMP activity during vessel stabilization in the resolution phase of angiogenesis become apparent (induction of endothelial quiescence, increased adhesion, and basement membrane deposition).79 80 81 The presence of unchecked proteolysis during this phase was associated with regression of newly formed vessels.

Although a large number of studies have demonstrated the antiangiogenic effect of synthetic MMP inhibitors,62 virtually all of these inhibitors lack specificity for a single MMP. For example, decreased vessel density and increased tumor cell apoptosis were observed in primary tumors and metastases in mice treated with KB-R7785, which inhibits MMPs -1, -3, and -9.82 Similar effects were observed with N-biphenylsulfonylphenylalanine hydroxamic acid, which potently inhibits MMPs -2, -9, and -14 but not MMPs -1, -3, or -7.83

MMPs have also been implicated in the generation of protein fragments that have angioinhibitory activity. These include, but are not limited to, angiostatin and endostatin. Thus, certain MMPs, including metalloelastase (MMP-12), gelatinase B (MMP-9), stromelysin-1 (MMP-3), and matrilysin (MMP-7), are capable of converting plasminogen into the angiogenesis-inhibiting angiostatin.84 85 86 87 Interestingly, it has been reported that tissue levels of MMPs -7 and -9 are increased in {alpha}1-integrin–null mice and that these mice have increased circulating levels of angiostatin.88 Tumor growth and vascularization were decreased in these mice, and this finding was attributed to the increase in circulating angiostatin levels. Endostatin is generated from the NC1 domain of collagen XVIII by several different proteinases (principally elastase and cathepsin L, but also several MMPs and other cathepsins).89 90 91


*    Requirement for Gelatinases and MT1-MMP During Angiogenesis
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
*Requirement for Gelatinases and...
down arrowMMP Requirement for Fibrinolysis...
down arrowRole of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
The importance of gelatinase activity in angiogenesis has been demonstrated in a rat Swarm chondrosarcoma model, in which the transition to the angiogenic phenotype was characterized by an increase in MMP-2 activity.92 In this model, angiogenesis and tumor growth could be inhibited by antisense MMP-2 oligonucleotides. In the ongoing search for clinically relevant MMP inhibitors, some degree of selectivity for the gelatinases has been achieved. For example, specific gelatinase-inhibitory peptides have been identified from phage display libraries.93 Cyclic peptides containing the sequence His-Trp-Gly-Phe, which are potent and selective inhibitors of MMP-2 and MMP-9, have been shown to inhibit tumor and endothelial cell migration in vitro and tumor growth and invasion in vivo. Moreover, peptide-displaying phage specifically targeted angiogenic blood vessels in vivo. Interestingly, endostatin has been reported to block MT1-MMP–mediated activation and catalytic activity of MMP-2 in endothelial cells and to form a stable complex with pro–MMP-2.94 Similarly, the properdin-like type 1 repeats found in thrombospondins -1 and -2 (which, like endostatin, are endogenous inhibitors of angiogenesis) bind specifically to MMP-2 and inhibit its catalytic activity.95

The C-terminal hemopexin-like domain of MMP-2 (termed PEX) has been shown to inhibit bFGF-induced angiogenesis in the chicken chorioallantoic membrane (CAM) and to disrupt tumor growth.96 The antiangiogenic activity of PEX has been demonstrated with both a recombinant protein and a lentiviral delivery approach.96 97 Physiologically active levels of PEX can purportedly be recovered from sites of active neovascularization in vivo. Not surprisingly, PEX prevents cell surface collagenolytic activity by blocking MMP-2 activation and enzyme activity.96 It has also been reported that PEX prevents binding of MMP-2 to the integrin {alpha}vß3.96 An organic compound (TSR1359) selected for its ability to inhibit MMP-2 binding to {alpha}vß3 has also been reported to have potent antiangiogenic activity in the CAM assay.98

Additional evidence for a requirement for gelatinases during angiogenesis has come from genetic studies in mice. With regard to MMP knockouts, although mice deficient in MMP-299 and MMP-9100 are viable, both have a clear angiogenic phenotype. Thus, in MMP-2–deficient mice, tumor-induced angiogenesis was markedly reduced in a dorsal air sac assay with B16-BL6 melanoma cells.101 This finding indicates that host-derived MMP-2 plays an important role in angiogenesis and tumor progression, with an important contribution from stromal cells. In MMP-9–deficient mice, bone growth plate angiogenesis was reduced, probably owing to delayed release of a positive angiogenesis regulator by hypertrophic cartilage.100

It has recently been reported that tumor angiogenesis is VEGF dependent in a transgenic mouse model of pancreatic beta-cell carcinogenesis (Rip1Tag2 mice). However, in these mice, there is no net increase in the level of expression of VEGF or its tyrosine kinase receptors. Instead, extracellular VEGF is mobilized from matrix stores, making it more available to VEGF receptors. This mobilization is dependent on MMP-9 activity (probably macrophage derived), which is upregulated during tumor progression, more specifically, during the switch from the prevascular to the vascular phase.102 Tumor progression was inhibited in Rip1Tag2xMMP-9–null double-transgenic mice. In contrast, although MMP-2 activity was increased in parallel with MMP-9 in Rip1Tag2 mice, tumor progression was unaffected in Rip1Tag2xMMP-2–null double transgenics. With regard to the PAs (urokinase-type PA [uPA] and tissue-type PA [tPA]), no reproducible changes in activity were noted during tumor progression, and tumor progression was unaffected in Rip1Tag2xuPA–null double-transgenic mice. Taken together, these findings reveal a specific requirement for MMP-9 in the angiogenic switch in this murine model of pancreatic beta-cell carcinogenesis.

MT1-MMP–deficient mice display severe skeletal defects that lead to death by 3 to 16 weeks of age.103 104 Other tissues in these null mice develop relatively normally. The skeletal defects are due in part to decreased vascular invasion of calcified cartilage. In the corneal angiogenesis assay, MT1-MMP–deficient mice also failed to respond to implanted FGF-2. Reduced activation of latent MMP-2 (but not MMP-9) was observed in various tissues of MT1-MMP–null mice.


*    MMP Requirement for Fibrinolysis During Angiogenesis
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
up arrowRequirement for Gelatinases and...
*MMP Requirement for Fibrinolysis...
down arrowRole of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
Traditionally, physiological fibrinolysis has been ascribed to the PA-plasmin system, and studies in null mice have confirmed this notion.105 Surprisingly, however, no overt phenotype related to aberrant angiogenesis has been observed in these mice, during either development or wound healing (see below). This finding raised the possibility that other protease systems might assume a fibrinolytic role during angiogenesis, ie, that in contrast to other cell types, endothelial cells invade fibrin matrixes in a plasmin-independent manner.106 This hypothesis has recently been confirmed in an ex vivo model in which tissue fragments from null mice were embedded in a 3-dimensional fibrin matrix.107 Thus, with the use of inhibitors of serine, cysteine, and aspartate proteinases, it was found that endothelial cell invasion and capillary morphogenesis progressed unabated. In contrast, these processes were completely inhibited by natural and synthetic MMP inhibitors. When a series of MMPs, including MMPs -1, -2, and -3 and a soluble form of MT1-MMP, were assessed for their fibrinolytic activity in a cell-free assay, all had the capacity to solubilize fibrin gels, and this activity could be completely blocked by MMP inhibitors. Quantitatively, the most potent fibrinolytic activity was ascribed to MT1-MMP.107 In a recent study on antiglomerular basement membrane nephritis, MMP-9 was found to be required for fibrinolysis, and in its absence, fibrin accumulated in glomeruli.108

These unexpected and highly novel observations suggest that when endothelial cells invade a provisional fibrin ECM scaffold, this event occurs in a plasmin-independent manner and may require the activity of MMPs such as MT1-MMP and possibly MMP-9. These observations have potentially far-reaching mechanistic and therapeutic implications.


*    Role of the PA-Plasmin System in Angiogenesis
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
up arrowRequirement for Gelatinases and...
up arrowMMP Requirement for Fibrinolysis...
*Role of the PA-Plasmin...
down arrowRequirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
Plasmin is a broad-spectrum protease of tryptic specificity that either directly or indirectly, through the activation of certain pro-MMPs, is presumed to hydrolyze many extracellular proteins, the most notable of which is fibrin. uPA and tPA, the principal activators of plasminogen, are the products of separate genes that are regulated independently by a variety of factors, including hormones and cytokines. Like plasmin, uPA and tPA are serine proteases of tryptic specificity, but in contrast to plasmin, they have a very restricted substrate specificity, namely, plasminogen. uPA (or, more precisely, its inactive precursor pro-uPA) is secreted as a soluble protein and binds with high affinity to a specific GPI–anchored cell surface receptor (uPA receptor, or uPAR) that is present on a variety of cells, including endothelial cells. Plasminogen and plasmin also associate with plasma membranes, and colocalization of uPA and plasminogen on the cell surface increases the efficiency of plasminogen activation and subsequent plasmin-dependent proteolysis. The existence of multiple, specific, physiological inhibitors of both plasmin (ie, {alpha}2-antiplasmin) and PAs (ie, PAI-1 and PAI-2) provides additional points of regulation along this protease cascade. The specificity, activity, and localization of serine protease inhibitors can be regulated by the ECM and other glycoproteins.3 105

With regard to localization studies, the overall picture is that uPA, uPAR, and PAI-1 are not expressed by quiescent endothelium. tPA, on the other hand, has been detected in the quiescent endothelium of a small percentage of arterioles, venules, and vasa vasorum of normal human tissues. In contrast, uPA, uPAR, and PAI-1 are all expressed during angiogenesis in vivo in a variety of settings. uPA and uPAR appear to be expressed by endothelial cells, and, depending on the situation, PAI-1 is expressed either by endothelial cells themselves or by nonendothelial (stromal and epithelial) cells, where it is thought to play a role in the preservation of matrix integrity.5 109 Little is known about tPA expression during angiogenesis.

These in vivo observations are amply supported by results obtained in vitro. That cultured endothelial cells (which are closer to activated than quiescent endothelium) produce uPA, uPAR, tPA, and PAI-1 has been known for some time, and their regulation by bFGF and VEGF has been described (Figure 2Down).2 5 It should be pointed out, however, that endothelial cells of human origin respond less well than do cells of bovine origin with regard to induction of PAs by bFGF and VEGF. The reason for the lack of response may be related to the chronic stimulation of these cells by the components of endothelial growth supplements (FGFs and probably VEGF) used to culture the cells. The response to VEGF also appears to be dependent on the vascular bed from which the cells were isolated. Thus, VEGF induces uPA and tPA in endothelial cells derived from the microvasculature but not in cells derived from the aorta (Figure 3Down).110 111 This distinction may have important implications for the regulation of angiogenesis, which traditionally has been considered to occur from preexisting vessels of the microvasculature. Hypoxia, a major stimulus for angiogenesis, has been reported to increase uPAR112 and PAI-1 (Figure 4Down)113 in endothelial cells. We have previously demonstrated that uPA, uPAR, and PAI-1 are increased in endothelial cells in a 2-dimensional wound-induced migration assay and that both migration and protease/inhibitor induction are dependent on endogenous bFGF.114 115 116 In a coculture system of endothelial cells and fibroblasts, PAI-1 mRNA and promoter activity were induced only in those fibroblasts apposed to sprouting but not resting endothelium.117 The authors reasoned that this may be of importance during sprouting, which constitutes the only period during which endothelial cells establish direct contact with fibroblasts. They suggested that the paracrine induction of PAI-1 provides a mechanism to negate excessive pericellular proteolysis.



View larger version (48K):
[in this window]
[in a new window]
 
Figure 2. Regulation of uPA, uPAR, tPA, and PAI-1 gene expression in bovine microvascular endothelial (BME) cells by VEGF. Confluent monolayers of BME cells were exposed to VEGF at the indicated concentrations for 4 or 15 hours. Total cellular RNA (5 µg/lane) was analyzed by Northern blotting. Replicate filters were probed with 32P-labeled bovine uPA, bovine uPAR, human tPA, and bovine PAI-1 cRNA probes. Filters were stained with methylene blue to reveal 28S and 18S ribosomal RNAs.



View larger version (101K):
[in this window]
[in a new window]
 
Figure 3. Differential regulation of PAs in bovine microvascular and aortic endothelial (BME and BAE, respectively) cells by bFGF and VEGF. (A) PA plaque assay. BME and BAE cells were seeded at 1 and 5x104 cells, respectively, per 35-mm tissue-culture dish in serum-containing medium. Twenty-four hours later, cells were treated with bFGF (10 ng/mL) or VEGF (100 ng/mL). Twelve to 15 hours later, cells were overlaid with a mixture containing agar, plasminogen, and casein. After incubation for various times at 37°C, dishes were photographed under dark-field illumination; black spots around individual cells are indicative of plasmin-mediated casein lysis. This experiment was performed in duplicate; representative dishes are shown. Both VEGF and bFGF increased plaque number and size in BME cells. In contrast, in BAE cells, although bFGF dramatically increased PA activity (resulting in complete lysis of the overlay), VEGF was without effect. (B) Zymographic and reverse-zymographic analysis of BME and BAE cells exposed to VEGF. Confluent monolayers were exposed to VEGF (20 ng/mL) for 15 hours. VEGF was from Genentech (VG) or Peprotech (VP). Cell extracts (CE) and culture supernatants (Sup) were analyzed by zymography (upper panels) and reverse zymography (lower panels). VEGF induced uPA and tPA in BME but not in BAE cells.



View larger version (33K):
[in this window]
[in a new window]
 
Figure 4. Induction of PAI-1 by hypoxia in bovine microvascular and aortic endothelial (BME and BAE, respectively) cells. Confluent monolayers were exposed to hypoxia/anoxia (H) for 15 hours. N indicates normoxia. (A) Total cellular RNA (5 µg/lane) was analyzed by Northern blotting. Filters were probed with a 32P-labeled bovine PAI-1 cRNA probe. Filters were stained with methylene blue to reveal 28S and 18S ribosomal RNAs. (B) Cell extracts were analyzed in duplicate by reverse zymography.

Angiogenesis results in the formation of new vessels in the blood vascular system. A comparable process, called lymphangiogenesis, is responsible for the formation of new vessels in the lymphatic system. Lymphangiogenesis has traditionally been overshadowed by the greater emphasis placed on angiogenesis. This is due in part to the lack of identification of lymphangiogenic factors as well as suitable markers with which to distinguish blood from lymphatic vascular endothelium. This scenario is changing rapidly after discovery of the first lymphangiogenic factors (VEGF-C and -D) as well as a limited number of lymphatic endothelium-specific markers.118 In adult tissues, new lymphatic capillaries grow by sprouting as extensions from preexisting lymphatics, much in the same way as new blood capillaries arise by sprouting from the preexisting microvasculature during angiogenesis. Although very little is known about the mechanisms of lymphangiogenesis, it has been demonstrated that VEGF, VEGF-C, and bFGF are capable of stimulating uPA, uPAR, tPA, and PAI-1 in bovine large-vessel lymphatic endothelial cells.119 120 121 122 The relevance of these in vitro observations to lymphangiogenesis in vivo remains to be determined.

The generation of mice deficient in components of the PA-plasmin system109 provided an opportunity to assess the role of individual components of this system during angiogenesis in vivo. Previous studies, both in vivo and in vitro, had pointed to a crucial role for the PA-plasmin system during angiogenesis. Unexpectedly, however, it was found that embryonic and postnatal development was unperturbed in these mice, at least from the perspective of an angiogenesis-associated phenotype.5 A seminal study on wound healing in plasminogen-deficient mice clearly defined a role for the PA-plasmin system during keratinocyte migration in vivo.123 However, although keratinocyte migration was severely impaired, there were no overt qualitative differences in the granulation tissue (inflammatory cell infiltration, fibroblast migration, and neovascularization) between wild-type and plasminogen-/- mice, suggesting that in this setting, angiogenesis is not PA-plasmin dependent. In addition, expression of 6 MMPs, including MMPs -1, -3, and -9 by keratinocytes and MMPs -2 and -11 and MT1-MMP by cells in granulation tissue, was unaffected in plasminogen-/- mice. These findings suggest that although keratinocyte migration is plasmin dependent, implementation of the genetic program that controls keratinocyte migration is plasmin independent.

Although developmental and wound healing–associated angiogenesis appears to be unaffected in uPA-, uPAR-, tPA-, PAI-1–, and plasminogen-null mice, several in vivo studies have demonstrated a requirement for this system during angiogenesis in other settings. For example, tumor-associated angiogenesis (vascular density) was inhibited in an athymic mouse model utilizing a human prostate carcinoma cell line, PC-3, that was stably transfected with human PAI-1.124 Although this study pointed to a role for PAs in tumor angiogenesis, it provided no mechanistic information, including the cell type specificity of the effect. More precise information has been provided in a murine model of myocardial infarction, in which postinfarction myocardial revascularization (angiogenesis) was severely impaired in uPA-/- mice.125 Because this phenotype could not be rescued by exogenously added VEGF, and because endothelial and smooth muscle cells expressed uPA during revascularization, it was concluded that the defect in angiogenesis was due to impaired endothelial cell invasion. Interestingly, when assayed in the rabbit cornea or on the chicken CAM, uPA itself had a proangiogenic effect.126 127 128 In the CAM, this event could be ascribed to the release of endogenous bFGF.128

uPA-uPAR Interactions Are Required for Angiogenesis
The importance of the interaction between uPA and uPAR during angiogenesis has been demonstrated in a number of in vivo systems. Thus, bFGF-induced angiogenesis in subcutaneously injected Matrigel was inhibited by a fusion protein consisting of the receptor-binding amino-terminal fragment of uPA and the Fc portion of human IgG, which functions as a high-affinity uPAR antagonist.129 Similarly, in syngeneic and xenograft murine tumor models, adenovirally delivered amino-terminal fragment specifically inhibited tumor angiogenesis.130 In a homologous immunocompetent rat model of tumor cells transfected with a mutant murine uPA that retains receptor binding but not proteolytic activity, microvessel density was markedly reduced.131 Tumor angiogenesis in several murine models was also inhibited by an octamer peptide derived from the non–receptor-binding region of uPA.132 133 These studies defined a novel epitope in uPA involved in the uPA-uPAR interaction.

PAI-1 Is Required for Angiogenesis
Localization studies have demonstrated that PAI-1 is strongly expressed in endothelial cells in a number of tumor types.5 Studies in PAI-1–null mice have revealed an absolute requirement for PAI-1 in tumor-induced angiogenesis. In one model, tumor and stromal cells are separated by the interposition of a type I collagen gel, which allows independent assessment of exogenously added tumor cell as well as of host stromal cell invasion.134 135 The absence of PAI-1 (but not of uPA, uPAR, or tPA) from the host markedly impaired tumor cell invasion and host-derived neovascularization. Reversal of this phenotype was achieved by adenovirally delivered human PAI-1 to PAI-1–null mice. In wild-type mice, PAI-1 expression in the stroma could be localized to endothelial and nonendothelial cells. Interestingly, although uPA was localized to newly formed blood vessels in wild-type mice, uPA was replaced by tPA in mice deficient in uPA, demonstrating the capacity for compensation between the PAs. The requirement for host PAI-1 (but not uPA) during tumor angiogenesis has also been demonstrated in a fibrosarcoma model in gene inactivation mice.136 bFGF-induced corneal angiogenesis was similarly impeded in PAI-1– but not in uPA-deficient mice.

Two potential mechanisms may explain why PAI-1 is essential for angiogenesis. First, by protecting the ECM against excessive degradation, PAI-1 may serve to maintain the matrix scaffold required for endothelial cell migration and tube formation.22 Second, a complex series of interactions have been described between PAI-1, uPAR, integrins, and the ECM component vitronectin.137 138 139 Alterations in PAI-1 expression and activity would therefore be expected to alter the adhesive, migratory, and growth properties of endothelial cells, which in turn would regulate angiogenesis. To address this question directly, adenovirus was used to deliver two mutant forms of PAI-1 to PAI-1–deficient mice in the collagen gel interposition model described above.135 The PAI-1 mutants either (1) bound vitronectin normally but failed to inhibit uPA or tPA or (2) inhibited PAs normally but had negligible binding to vitronectin. Angiogenesis was restored by the PAI-1 mutant that retained PA inhibitory activity but not by the mutant that bound vitronectin but failed to inhibit the PAs, demonstrating that the requirement for PAI-1 in this model is due to inhibition of excessive proteolysis rather than inhibition of cellular adhesion to vitronectin. In a separate study, exogenously added PAI-1 ("at therapeutic concentrations") was shown to inhibit bFGF-induced angiogenesis in the CAM.140 With use of a variety of PAI-1 mutants, this activity could be ascribed both to PAI-1’s antiprotease activity as well as its vitronectin-binding capacity.

Does tPA Play a Role in Angiogenesis?
Little is known about the role of tPA in angiogenesis. In vivo, tPA antigen is localized to the endothelium of the microvasculature,141 which, as morphological studies have revealed, is the region of the vascular bed from which new blood vessels are formed during angiogenesis. The presence of tPA in angiogenic endothelium has yet to be described. In vitro, tPA has been implicated in capillary-like tube formation on matrices constituted of type I collagen, Matrigel, and the explanted amnion.142 143 144 145 146 The requirement for tPA in endothelial cell migration in vitro has been demonstrated in some studies147 but not in others.148 Interestingly, the combination of bFGF and VEGF induced tPA mRNA and enzyme activity in a synergistic manner in cultured endothelial cells.111 In this study, immunofluorescence analysis revealed that cell-associated tPA was colocalized with von Willebrand factor, a marker for Weibel-Palade bodies, which are regulated, endothelial cell–specific storage granules. A combination of bFGF and VEGF increased the number of tPA-positive cells as well as the number of tPA-positive granules per cell. Angiostatin, an endogenous inhibitor of angiogenesis, has been shown to inhibit tPA-catalyzed plasminogen activation in endothelial cells.149

At present, one can only speculate on the function of tPA in Weibel-Palade bodies in the context of angiogenesis. An attractive role would be to protect newly forming blood vessels from thrombotic occlusion. Indeed, stagnant blood in the forming dead end of new blood vessels would be particularly prone to coagulation, first because of the potential exposure of blood to the ECM (and in particular, to collagen) in the hyperpermeable and rapidly remodeling migrating sprout and second, because activated blood coagulation would be less easily washed away. To overcome this problem, locally generated thrombin would result in the acute release of tPA from Weibel-Palade bodies,150 151 which in turn would aid in the removal of fibrin deposits.

It is of interest to note that secretion of MMP-1 and MMP-2, but not of TIMP-2, can occur through a posttranscriptional mechanism in endothelial cells.152 MMPs are known to be regulated at different levels; this study indicates that, in endothelial cells, the stimulation of MMPs can also occur at the level of secretion, providing a mechanism for their rapid mobilization in the early phases of angiogenesis. Whether these enzymes, like tPA, are localized to Weibel-Palade bodies (regulated, endothelial cell–specific storage granules) remains to be determined. The intracellular accumulation of MMP-9 in secretory vesicles in response to phorbol esters has been reported.71


*    Requirement for the MMP and PA-Plasmin Systems in Polyomavirus Middle T Oncogene–Induced Vascular Tumor Formation
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
up arrowRequirement for Gelatinases and...
up arrowMMP Requirement for Fibrinolysis...
up arrowRole of the PA-Plasmin...
*Requirement for the MMP...
down arrowConclusions and Perspectives
down arrowReferences
 
Endothelial cells are the primary target of the transforming ability of the polyomavirus middle T (PymT) oncogene. Tumors induced by PymT (called endotheliomas) have been used as a model system for endothelial cell tumors. Although significant morphological differences exist between endotheliomas and human vascular tumors (including hemangiomas), the PymT system does provide a good functional model for hemangiomas because (1) the tumors are endothelium-specific and organ-nonspecific; (2) there appears to be rapid, uncontrolled endothelial cell proliferation; and (3) mice develop many signs of the Kasabach-Merritt syndrome (ie, thrombocytopenia, anemia, and associated splenomegaly), which may be a life-threatening complication of hemangiomas in humans. It has also been suggested that endotheliomas may serve as a model system for vascular malformations. This is due to the cavernous nature of the lesions, which is a characteristic feature of cavernous angiomas in humans. Finally, because recruited host cells are an important component of these tumors, endotheliomas have also been used as a model system for Kaposi’s sarcoma.153

PymT-transformed endothelial cells (End. cells), which can be isolated with relative ease, have the potential to grow indefinitely, and they retain many important features of differentiated endothelium. Endotheliomas can be induced not only by PymT itself but also by subcutaneous or intraperitoneal injection of End. cells. The following is a working hypothesis for endothelioma formation after subcutaneous injection.153 End. cells invade and integrate into host blood vessels, leading to their rupture and subsequent hemorrhage. This event in turn is followed by rapid recruitment of host endothelial and nonendothelial cells. Recruited endothelial cells form new capillary blood vessels, which feed the growing cystic tumor. Recruitment is dependent on the continuous presence of End. cells and mainly involves host cell migration with low levels of proliferation. The signal for host endothelial cell recruitment is not known, but it probably originates from the injected End. cells as well as from the intense inflammatory reaction observed at the periphery of the hemorrhagic cysts. It is likely that in addition to host cell recruitment, proliferating End. cells themselves contribute significantly to tumor expansion during the later phases of tumor growth. Taraboletti et al154 and Vergani et al155 have partially characterized an End. cell–derived motility factor that may be responsible for recruitment of host endothelial cells.

An in vitro model has been developed to study the autonomous, morphogenetic behavior of End. cells.24 This consists of growing End. cells in suspension in 3-dimensional fibrin gels. In these fibrin gels, End. cells proliferate rapidly, and after 10 to 14 days form large cystic structures lined by a monolayer of endothelial cells (Figure 5Down). These cystlike structures are strikingly reminiscent of the cavernous endotheliomas that develop in vivo. Under the same experimental conditions, nontransformed endothelial cells from a variety of species and organs form elongated, branching, tubelike structures (Figure 5Down); in no instance are cystlike structures seen. The fibrin gel model, in which normal vascular morphogenesis is disrupted, ie, formation of endothelium-lined cystlike structures rather than tubelike structures, provides a powerful in vitro system for investigating the mechanisms of protease-dependent tumor formation.



View larger version (98K):
[in this window]
[in a new window]
 
Figure 5. In vitro morphogenetic behavior of normal mouse brain endothelial cells (BECs) and PymT-expressing endothelioma cells grown within 3-dimensional fibrin gels. (a) Phase-contrast view of a network of branching and anastomosing cords formed by primary mouse BECs; fine slitlike lumina are indicated by the small arrows. (b) Spherical cyst formed by PymT-expressing endothelial cells. In this picture, the focus is approximately on the equatorial plane of the cyst. The endothelial cells lining the "floor" and "roof" of the cavity appear blurred in the center of the cyst. Bar=100 µm. (Reprinted from Cell, vol 62, Montesano et al24 : Increased proteolytic activity is responsible for the aberrant morphogenetic behaviour of endothelial cells expressing middle T oncogene, pp 435–445, copyright 1997, with permission from Elsevier Science.)

With regard to MMPs and endothelioma formation in vivo, it has been demonstrated that End. cell–induced endothelioma growth can be inhibited by the broad-spectrum hydroxamic acid–based peptide derivative Batimastat (also known as BB94).156 Daily local injection of the inhibitor at the site of End. cell injection increased tumor doubling time in a dose-dependent manner. Inhibition of tumor growth lasted as long as Batimastat was given, and when treatment was stopped, the tumors resumed a pattern of growth similar to that seen in controls. Histologically, treated tumors consisted of solid, cellular aggregates that circumscribed small- to medium-size blood-filled spaces. Subcutaneous hemorrhage was rarely observed in treated animals. In a subsequent study, these authors demonstrated that tumor growth could be efficiently inhibited by overexpressing TIMP-2 in End. cells.155 When compared with the cavernous tumors induced by wild-type cells, tumors induced by TIMP-2 overproducers had small-to-medium blood-filled spaces and multiple apoptotic foci.

With regard to the PA-plasmin system, End. cells display increased PA activity when compared with nontransformed endothelial cells, which can be accounted for by an increase in uPA and, in some cell lines, by a concomitant decrease in PAI-1.24 157 158 159 The mechanism for this increase is not known, although it has been shown that PymT increases uPA gene activation without influencing uPA mRNA stability.158 Taken together with the observation that transformed endothelial cells form cystlike structures when embedded in fibrin gels (see above), these findings demonstrate that excessive proteolysis is associated with aberrant vascular morphogenesis. Reduction of this activity by inhibiting plasmin restores normal morphogenetic properties to these cells, ie, the formation of capillary-like tubes. These findings clearly implicate increased PA-plasmin–mediated proteolysis in aberrant vascular morphogenesis in vitro.24

Based on these in vitro observations, it was hypothesized that the PA-plasmin system would also be required for endothelioma formation in vivo. This hypothesis was tested directly in uPA-, tPA-, PAI-1–, and plasminogen-deficient mice. Essentially, tumor formation after viral infection/transduction was unaffected in the different genotypes, suggesting that the primary transformation process is PA-plasmin independent. However, compared to tumors induced by injection of wild-type End. cells, tumor incidence and latency were increased in uPA-/- and double-transgenic uPA:tPA-/- mice but not in tPA-/- or PAI-1-/- mice. Tumor incidence and latency were also increased when uPA-/- and uPA:tPA-/- End. cells were injected into wild-type mice.160 These genetic studies demonstrated that components of the PA-plasmin system, in particular uPA, are critical for tumor growth in vivo. With respect to the in vitro morphogenetic behavior of End. cells derived from protease-knockout mice, although PA activity was necessary, it did not appear to be sufficient for cyst formation.160

The plasminogen-dependent and -independent proteolytic activity of wild-type and mutant End. cells has been determined.161 Thus, plasminogen activation with wild-type and tPA-/- cells was comparable but was reduced 4-fold with uPA-/- cells and increased 3-fold with PAI-1-/- cells. Lysis of an 125I-labeled matrix in the presence of plasminogen was comparable in wild-type, tPA-/-, and PAI-1-/- cells but was significantly reduced in uPA-/- cells. Lysis of a human umbilical vein endothelial cell–derived, [3H]proline-labeled ECM in the presence of plasminogen with wild-type, tPA-/-, and PAI-1-/- cells was comparable but was virtually abolished in uPA-/- cells. These findings provide a mechanism for the reduction in tumor growth seen in the absence of uPA (see above).

Finally, using the in vitro fibrin gel model, we have infrequently observed the formation of cystlike structures by End. cells deficient in both uPA and tPA (Pepper et al, unpublished observations, 2000). Clonal populations of these cells have been obtained and in which cyst formation can be completely inhibited by synthetic MMP inhibitors (Pepper et al, unpublished observations, 2000). This result implicates another protease system(s) (possibly MMPs) in the fibrinolysis required for cyst formation and is in accord with the emerging notion of MMP-mediated fibrinolysis in endothelial cells.


*    Conclusions and Perspectives
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
up arrowRequirement for Gelatinases and...
up arrowMMP Requirement for Fibrinolysis...
up arrowRole of the PA-Plasmin...
up arrowRequirement for the MMP...
*Conclusions and Perspectives
down arrowReferences
 
Increased understanding of the mechanisms of angiogenesis has opened up novel and exciting therapeutic avenues, and considerable benefit can now be derived in the clinical setting from manipulating angiogenesis, either positively or negatively.1 162

With respect to MMPs, potential targets for inhibiting angiogenesis include the gelatinases and MT-MMPs. The additional role of MT1-MMP in fibrinolysis during angiogenesis makes this a particularly attractive target. Several novel synthetic inhibitors are currently being investigated in clinical trials.163 164 However, despite the abundance of promising preclinical data, the clinical application of MMP inhibitors has to date met with limited success, and a number of phase III trials have been discontinued.165 Because MMPs have been implicated in the generation of molecules with antiangiogenic activity (eg, endostatin), MMP inhibition may result in the stimulation rather than inhibition of angiogenesis. Furthermore, one hydroxamate-based MMP inhibitor has been reported to promote the formation of liver metastases in a murine breast cancer xenotransplantation model,166 and systemic administration of human TIMP-4 stimulates the growth of human breast cancer cells in a murine xenotransplantation model.167 At present, therefore, a degree of uncertainty surrounds the use of MMP inhibitors in cancer, and it appears that under certain circumstances, MMP inhibition may even be detrimental to cancer patients.

The studies on the PA-plasmin system cited in this review provide ample evidence for the requirement for this system during angiogenesis in vivo. In particular, a role for uPAR and PAI-1 has been clearly defined, with uPA playing a more ancillary role. The counterintuitive possibility that inhibition of PAI-1 might serve to inhibit angiogenesis is one that merits further investigation. To date, little is known about the role of tPA in angiogenesis.

The tumor vasculature has become a key target in the war against cancer.168 Increased understanding of the complex roles of the MMP and PA-plasmin systems in the regulation of angiogenesis will provide a rational basis for the development of antiangiogenesis-based therapeutic strategies for cancer and other angiogenesis-associated diseases.


*    Acknowledgments
 
Work in the author’s laboratory was supported principally by the Swiss National Science Foundation. The author would like to thank Roberto Montesano and Egbert Kuithof for critically reading this manuscript.

Received April 6, 2001; accepted May 25, 2001.


*    References
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowRole of the MMP...
up arrowRequirement for Gelatinases and...
up arrowMMP Requirement for Fibrinolysis...
up arrowRole of the PA-Plasmin...
up arrowRequirement for the MMP...
up arrowConclusions and Perspectives
*References
 
1. Pepper MS. Manipulating angiogenesis: from basic science to the bedside. Arterioscler Thromb Vasc Biol. 1997;17:605–619.[Abstract/Free Full Text]

2. Mignatti P, Rifkin DB. Plasminogen activators and matrix metalloproteinases in angiogenesis. Enzyme Protein. 1996;49:117–137.[Medline] [Order article via Infotrieve]

3. Andreasen PA, Egelund R, Petersen HH. The plasminogen activation system in tumor growth, invasion, and metastasis. Cell Mol Life Sci. 2000;57:25–40.[Medline] [Order article via Infotrieve]

4. Vu TH, Werb Z. Matrix metalloproteinases: effectors of development and normal physiology. Genes Dev. 2000;14:2123–2133.[Free Full Text]

5. Pepper MS, Montesano R, Mandriota SJ, Orci L, Vassalli JD. Angiogenesis: a paradigm for balanced extracellular proteolysis during cell migration and morphogenesis. Enzyme Protein. 1996;49:138–162.[Medline] [Order article via Infotrieve]

6. Clark ER, Clark EL. Microscopic observations on the growth of blood capillaries in the living mammal. Am J Anat. 1939;64:251–301.

7. Kwaan HC, Astrup T. Fibrinolytic activity of reparative connective tissue. J Pathol Bacteriol. 1964;87:409–414.[Medline] [Order article via Infotrieve]

8. Kalebic T, Garbisa S, Glaser B, Liotta LA. Basement membrane collagen: degradation by migrating endothelial cells. Science. 1983;221:281–283.[Abstract/Free Full Text]

9. Bouck N. Tumor angiogenesis: the role of oncogenes and tumor suppressor genes. Cancer Cells. 1990;2:179–185.[Medline] [Order article via Infotrieve]

10. Hanahan D, Folkman J. Patterns and emerging mechanisms of the angiogenic switch during tumorigenesis. Cell. 1996;86:353–364.[Medline] [Order article via Infotrieve]

11. Dvorak HF, Nagy JA, Feng D, Brown LF, Dvorak AM. Vascular permeability factor/vascular endothelial growth factor and the significance of microvascular hyperpermeability in angiogenesis. Curr Top Microbiol Immunol. 1999;237:97–132.[Medline] [Order article via Infotrieve]

12. Ferrara N. Vascular endothelial growth factor: molecular and biological aspects. Curr Top Microbiol Immunol. 1999;237:1–30.[Medline] [Order article via Infotrieve]

13. Dow JK, deVere White RW. Fibroblast growth factor 2: its structure and property, paracrine function, tumor angiogenesis, and prostate-related mitogenic and oncogenic functions. Urology. 2000;55:800–806.[Medline] [Order article via Infotrieve]

14. Gerwins P, Skoldenberg E, Claesson-Welsh L. Function of fibroblast growth factors and vascular endothelial growth factors and their receptors in angiogenesis. Crit Rev Oncol Hematol. 2000;34:185–194.[Medline] [Order article via Infotrieve]

15. Pepper MS, Ferrara N, Orci L, Montesano R. Potent synergism between vascular endothelial growth factor and basic fibroblast growth factor in the induction of angiogenesis in vitro. Biochem Biophys Res Commun. 1992;189:824–831.[Medline] [Order article via Infotrieve]

16. Goto F, Goto K, Weindel K, Folkman J. Synergistic effects of vascular endothelial growth factor and basic fibroblast growth factor on the proliferation and cord formation of bovine capillary endothelial cells within collagen gels. Lab Invest. 1993;69:508–517.[Medline] [Order article via Infotrieve]

17. Asahara T, Bauters C, Zheng LP, Takeshita S, Bunting S, Ferrara N, Symes JF, Isner JM. Synergistic effect of vascular endothelial growth factor and basic fibroblast growth factor on angiogenesis in vivo. Circulation. 1995;92(suppl II):II-365–II-371.

18. Hu DE, Fan T-PD. Suppression of VEGF-induced angiogenesis by the protein tyrosine kinase inhibitor, lavendustin A. Br J Pharmacol. 1995;114:262–268.[Medline] [Order article via Infotrieve]

19. Cao Y. Therapeutic potentials of angiostatin in the treatment of cancer. Haematologica. 1999;84:643–650.[Abstract/Free Full Text]

20. Cirri L, Donnini S, Morbidelli L, Chiarugi P, Ziche M, Ledda F. Endostatin, a promising drug for antiangiogenic therapy. Int J Biol Markers. 1999;14:263–267.[Medline] [Order article via Infotrieve]

21. Keshet E, Ben-Sasson SA. Anticancer drug targets: approaching angiogenesis. J Clin Invest. 1999;104:1497–1501.[Medline] [Order article via Infotrieve]

22. Pepper MS, Montesano R. Proteolytic balance and capillary morphogenesis. Cell Differ Dev. 1990;32:319–327.[Medline] [Order article via Infotrieve]

23. Saarialho-Kere UK, Pentland AP, Birkedal-Hansen H, Parks WC, Welgus HG. Distinct populations of basal keratinocytes express stromelysin-1 and stromelysin-2 in chronic wounds. J Clin Invest. 1994;94:79–88.

24. Montesano R, Pepper MS, Möhle-Steinlein U, Risau W, Wagner EF, Orci L. Increased proteolytic activity is responsible for the aberrant morphogenetic behavior of endothelial cells expressing middle T oncogene. Cell. 1990;62:435–445.[Medline] [Order article via Infotrieve]

25. Pepper MS, Belin D, Montesano R, Orci L, Vassalli JD. Transforming growth factor-ß1 modulates basic fibroblast growth factor-induced proteolytic and angiogenic properties of endothelial cells in vitro. J Cell Biol. 1990;111:743–755.[Abstract/Free Full Text]

26. Mazzieri R, Masiero L, Zanetta L, Monea S, Onisto M, Garbisa S, Mignatti P. Control of type IV collagenase activity by components of the urokinase-plasmin system: a regulatory mechanism with cell-bound reactants. EMBO J. 1997;16:2319–2332.[Medline] [Order article via Infotrieve]

27. Flaumenhaft R, Rifkin DB. The extracellular regulation of growth factor action. Mol Biol Cell. 1992;3:1057–1065.[Medline] [Order article via Infotrieve]

28. Houck KA, Leung DW, Rowland AM, Winer J, Ferrara N. Dual regulation of vascular endothelial growth factor bioavailability by genetic and proteolytic mechanisms. J Biol Chem. 1992;267:26031–26037.[Abstract/Free Full Text]

29. Black RA, Rauch CT, Kozlosky CJ, Peschon JJ, Slack JL, Wolfson MF, Castner BJ, Stocking KL, Reddy P, Srinivasan S, Nelson N, Boiani N, Schooley KA, Gerhart M, Davis R, Fitzner JN, Johnson RS, Paxton RJ, March CJ, Cerretti DP. A metalloproteinase disintegrin that releases tumour-necrosis factor-{alpha} from cells. Nature. 1997;385:729–733.[Medline] [Order article via Infotrieve]

30. McQuibban GA, Gong JH, Tam EM, McCulloch CA, Clark-Lewis I, Overall CM. Inflammation dampened by gelatinase A cleavage of monocyte chemoattractant protein-3. Science. 2000;289:1202–1206.[Abstract/Free Full Text]

31. Sage EH. Pieces of eight: bioactive fragments of extracellular proteins as regulators of angiogenesis. Trends Cell Biol. 1997;7:182–186.[Medline] [Order article via Infotrieve]

32. O’Reilly MS, Holmgren L, Shing Y, Chen C, Rosenthal RA, Moses M, Lane WS, Cao Y, Sage EH, Folkman J. Angiostatin: a novel angiogenesis inhibitor that mediates the suppression of metastases by a Lewis lung carcinoma. Cell. 1994;79:315–328.[Medline] [Order article via Infotrieve]

33. O’Reilly MS, Boehm T, Shing Y, Fukai N, Vasios G, Lane WS, Flynn E, Birkhead JR, Olsen BR, Folkman J. Endostatin, an endogenous inhibitor of angiogenesis and tumor growth. Cell. 1997;88:277–285.[Medline] [Order article via Infotrieve]

34. Colorado PC, Torre A, Kamphaus G, Maeshima Y, Hopfer H, Takahashi K, Volk R, Zamborsky ED, Herman S, Sarkar PK, Ericksen MB, Dhanabal M, Simons M, Post M, Kufe DW, Weichselbaum RR, Sukhatme VP, Kalluri R. Anti-angiogenic cues from vascular basement membrane collagen. Cancer Res. 2000;60:2520–2526.[Abstract/Free Full Text]

35. Kamphaus GD, Colorado PC, Panka DJ, Hopfer H, Ramchandran R, Torre A, Maeshima Y, Mier JW, Sukhatme VP, Kalluri R. Canstatin, a novel matrix-derived inhibitor of angiogenesis and tumor growth. J Biol Chem. 2000;275:1209–1215.[Abstract/Free Full Text]

36. Maeshima Y, Colorado PC, Kalluri R. Two RGD-independent {alpha}vß3 integrin binding sites on tumstatin regulate distinct anti-tumor properties. J Biol Chem. 2000;275:23745–23750.[Abstract/Free Full Text]

37. Maeshima Y, Colorado PC, Torre A, Holthaus KA, Grunkemeyer JA, Ericksen MB, Hopfer H, Xiao Y, Stillman IE, Kalluri R. Distinct antitumor properties of a type IV collagen domain derived from basement membrane. J Biol Chem. 2000;275:21340–21348.[Abstract/Free Full Text]

38. Ramchandran R, Dhanabal M, Volk R, Waterman MJF, Segal M, Lu H, Knebelmann B, Sukhatme VP. Antiangiogenic activity of restin, NC10 domain of human collagen XV: comparison to endostatin. Biochem Biophys Res Commun. 1999;255:735–739.[Medline] [Order article via Infotrieve]

39. Pike SE, Yao L, Jones KD, Cherney B, Appella E, Sakaguchi K, Nakhasi H, Teruya-Feldstein J, Wirth P, Gupta G, Tosato G. Vasostatin, a calreticulin fragment, inhibits angiogenesis and suppresses tumor growth. J Exp Med. 1998;188:2349–2356.[Abstract/Free Full Text]

40. Colman RW, Jameson BA, Lin Y, Johnson D, Mousa SA. Domain 5 of high molecular weight kininogen (kininostatin) down-regulates endothelial cell proliferation and migration and inhibits angiogenesis. Blood. 2000;95:543–550.[Abstract/Free Full Text]

41. O’Reilly MS, Pirie-Shepherd S, Lane WS, Folkman J. Antiangiogenic activity of the cleaved conformation of the serpin antithrombin. Science. 1999;285:1926–1928.[Abstract/Free Full Text]

42. Woessner JF. The matrix metalloproteinase family. In: Parks WC, Mecham RP, eds. Matrix Metalloproteinases. San Diego, Calif: Academic Press; 1998:1–14.

43. Johansson N, Ahonen M, Kähäri VM. Matrix metalloproteinases in tumor invasion. Cell Mol Life Sci. 2000;57:5–15.[Medline] [Order article via Infotrieve]

44. Seiki M. Membrane-type metalloproteinases. APMIS. 1999;107:137–143.[Medline] [Order article via Infotrieve]

45. Murphy G, Stanton H, Cowell S, Butler G, Knäuper V, Atkinson S, Gavrilovic J. Mechanisms for pro matrix metalloproteinase activation. APMIS. 1999;107:38–44.[Medline] [Order article via Infotrieve]

46. Brew K, Dinakarpandian D, Nagase H. Tissue inhibitors of metalloproteinases: evolution, structure and function. Biochim Biophys Acta. 2000;1477:267–283.[Medline] [Order article via Infotrieve]

47. Haas TL, Madri JA. Extracellular matrix-driven matrix metalloproteinase production in endothelial cells. Trends Cardiovasc Med. 1999;9:70–77.[Medline] [Order article via Infotrieve]

48. Puyraimond A, Fridman R, Lemesle M, Arbeille B, Menashi S. MMP-2 colocalizes with caveolae on the surface of endothelial cells. Exp Cell Res. 2001;262:28–36.[Medline] [Order article via Infotrieve]

49. Lafleur MA, Forsyth PA, Atkinson SJ, Murphy G, Edwards DR. Perivascular cells regulate endothelial membrane type-1 matrix metalloproteinase activity. Biochem Biophys Res Commun. 2001;282:463–473.[Medline] [Order article via Infotrieve]

50. Salo T, Makela M, Kylmaniemi M, Autio-Harmainen H, Larjava H. Expression of matrix metalloproteinase-2 and -9 during early human wound healing. Lab Invest. 1994;70:176–182.[Medline] [Order article via Infotrieve]

51. Soini Y, Hurskainen T, Hoyhtya M, Oikarinen A, Autio-Harmainen H. 72 KD and 92 KD type IV collagenase, type IV collagen, and laminin mRNAs in breast cancer: a study by in situ hybridization. J Histochem Cytochem. 1994;42:945–951.[Abstract]

52. Karelina TV, Goldberg GI, Eisen AZ. Matrix metalloproteinases in blood vessel development in human fetal skin and in cutaneous tumors. J Invest Dermatol. 1995;105:411–417.[Medline] [Order article via Infotrieve]

53. Ahrens D, Kock AE, Pope RM, Stein-Picarella M, Niedbala MJ. Expression of matrix metalloproteinase 9 (96-kd gelatinase B) in human rheumatoid arthritis. Arthritis Rheum. 1996;39:1576–1587.[Medline] [Order article via Infotrieve]

54. Musso O, Theret N, Campion JP, Turlin B, Milani S, Grappone C, Clement B. In situ detection of matrix metalloproteinase-2 (MMP2) and the metalloproteinase inhibitor TIMP2 transcripts in human primary hepatocellular carcinoma and in liver metastasis. J Hepatol. 1997;26:593–605.[Medline] [Order article via Infotrieve]

55. Nagashima Y, Hasegawa S, Koshikawa N, Taki A, Ichikawa Y, Kitamura H, Misugi K, Kihira Y, Matuo Y, Yasumitsu H, Miyazaki K. Expression of matrilysin in vascular endothelial cells adjacent to matrilysin-producing tumors. Int J Cancer. 1997;72:441–445.[Medline] [Order article via Infotrieve]

56. Rooprai HK, Van Meter T, Rucklidge GJ, Hudson L, Everall IP, Pilkington GJ. Comparative analysis of matrix metalloproteinases by immunocytochemistry, immunohistochemistry and zymography in human primary brain tumours. Int J Oncol. 1998;13:1153–1157.[Medline] [Order article via Infotrieve]

57. Vagnoni KE, Zheng J, Magness RR. Matrix metalloproteinases-2 and -9, and tissue inhibitor of metalloproteinases-1 of the sheep placenta during the last third of gestation. Placenta. 1998;19:447–455.[Medline] [Order article via Infotrieve]

58. Iurlaro M, Loverro G, Vacca A, Cormio G, Ribatti D, Minischetti M, Ria R, Bruno M, Selvaggi L. Angiogenesis extent and expression of matrix metalloproteinase-2 and -9 correlate with upgrading and myometrial invasion in endometrial carcinoma. Eur J Clin Invest. 1999;29:793–801.[Medline] [Order article via Infotrieve]

59. Forsyth PA, Wong H, Laing TD, Rewcastle NB, Morris DG, Muzik H, Leco KJ, Johnston RN, Brasher PM, Sutherland G, Edwards DR. Gelatinase-A (MMP-2), gelatinase-B (MMP-9), and membrane type matrix metalloproteinase-1 (MT1-MMP) are involved in different aspects of the pathophysiology of malignant gliomas. Br J Cancer. 1999;79:1828–1835.[Medline] [Order article via Infotrieve]

60. Freitas S, Meduri G, Le Nestour E, Bausero P, Perrot-Applanat M. Expression of metalloproteinases and their inhibitors in blood vessels in human endometrium. Biol Reprod. 1999;61:1070–1082.[Abstract/Free Full Text]

61. Ribatti D, Nico B, Vacca A, Iurlaro M, Roncali L. Temporal expression of the matrix metalloproteinase MMP-2 correlates with fibronectin immunoreactivity during the development of the vascular system in the chick embryo chorioallantoic membrane. J Anat. 1999;195:39–44.

62. Moses MA. The regulation of neovascularization by matrix metalloproteinases and their inhibitors. Stem Cells. 1997;15:180–189.[Medline] [Order article via Infotrieve]

63. Chan VT, Zhang DN, Nagaravapu U, Hultquist K, Romero LI, Herron GS. Membrane-type matrix metalloproteinases in human dermal microvascular endothelial cells: expression and morphogenetic correlation. J Invest Dermatol. 1998;111:1153–1159.[Medline] [Order article via Infotrieve]

64. Lamoreaux WJ, Fitzgerald ME, Reiner A, Hasty KA, Charles ST. Vascular endothelial growth factor increases release of gelatinase A and decreases release of tissue inhibitor of metalloproteinases by microvascular endothelial cells in vitro. Microvasc Res. 1998;55:29–42.[Medline] [Order article via Infotrieve]

65. Unemori EN, Ferrara N, Bauer EA, Amento E. Vascular endothelial growth factor induces interstitial collagenase expression in human endothelial cells. J Cell Physiol. 1992;153:5575–5562.

66. Zucker S, Mirza H, Conner CE, Lorenz AF, Drews MH, Bahou WF, Jesty J. Vascular endothelial growth factor induces tissue factor and matrix metalloproteinase production in endothelial cells: conversion of prothrombin to thrombin results in progelatinase A activation and cell proliferation. Int J Cancer. 1998;75:780–786.[Medline] [Order article via Infotrieve]

67. Okamura K, Sato Y, Matsuda T, Hamanaka R, Ono M, Kohno K, Kuwano M. Endogenous basic fibroblast growth factor-dependent induction of collagenase and interleukin-6 in tumor necrosis factor-treated human microvascular endothelial cells. J Biol Chem. 1991;266:19162–19165.[Abstract/Free Full Text]

68. Cornelius LA, Nehring LC, Roby JD, Parks WC, Welgus HG. Human dermal microvascular endothelial cells produce matrix metalloproteinases in response to angiogenic factors and migration. J Invest Dermatol. 1995;105:170–176.[Medline] [Order article via Infotrieve]

69. Haas TL, Davis SJ, Madri JA. Three-dimensional type I collagen lattices induce coordinate expression of matrix metalloproteinases MT1-MMP and MMP-2 in microvascular endothelial cells. J Biol Chem. 1998;273:3604–3610.[Abstract/Free Full Text]

70. Haas TL, Stitelman D, Davis SJ, Apte SS, Madri JA. Egr-1 mediates extracellular matrix-driven transcription of membrane type I matrix metalloproteinase in endothelium. J Biol Chem. 1999;274:22679–22685.[Abstract/Free Full Text]

71. Nguyen M, Arkell J, Jackson CJ. Three-dimensional collagen matrices induce delayed but sustained activation of gelatinase A in human endothelial cells via MT1-MMP. Int J Biochem Cell Biol. 2000;32:621–631.[Medline] [Order article via Infotrieve]

72. Yan L, Moses MA, Huang S, Ingber DE. Adhesion-dependent control of matrix metalloproteinase-2 activation in human capillary endothelial cells. J Cell Sci. 2000;113:3979–3987.[Abstract]

73. Partridge CA, Phillips PG, Niedbala MJ, Jeffrey JJ. Localization and activation of type IV collagenase/gelatinase at endothelial focal contacts. Am J Physiol. 1997;272:L813–L822.[Abstract/Free Full Text]

74. Sang QX. Complex role of matrix metalloproteinases in angiogenesis. Cell Res. 1998;8:171–177.[Medline] [Order article via Infotrieve]

75. Stetler-Stevenson WG. Matrix metalloproteinases in angiogenesis: a moving target for therapeutic intervention. J Clin Invest. 1999;103:1237–1241.[Medline] [Order article via Infotrieve]

76. Raza SL, Cornelius LA. Matrix metalloproteinases: pro- and anti-angiogenic activities. J Invest Dermatol Symp Proc. 2000;5:47–54.

77. Guedez L, McMarlin AJ, Kingma DW, Bennett TA, Stetler-Stevenson M, Stetler-Stevenson WG. Tissue inhibitor of metalloproteinase-1 alters the tumorigenicity of Burkitt’s lymphoma via divergent effects on tumor growth and angiogenesis. Am J Pathol. 2001;158:1207–1215.[Abstract/Free Full Text]

78. Hajitou A, Sounni NE, Devy L, Grignet-Debrus C, Lewalle JM, Li H, Deroanne CF, Lu H, Colige A, Nusgens BV, Frankenne F, Maron A, Yeh P, Perricaudet M, Chang Y, Soria C, Calberg-Bacq CM, Foidart JM, Noel A. Down-regulation of vascular endothelial growth factor by tissue inhibitor of metalloproteinase-2: effect on in vivo mammary tumor growth and angiogenesis. Cancer Res. 2001;61:3450–3457.[Abstract/Free Full Text]

79. Kräling BM, Wiederschain DG, Boehm T, Rehn M, Mulliken JB, Moses MA. The role of matrix metalloproteinase activity in the maturation of human capillary endothelial cells in vitro. J Cell Sci. 1999;112:1599–1609.[Abstract]

80. Zhu WH, Guo X, Villaschi S, Nicosia RF. Regulation of vascular growth and regression by matrix metalloproteinases in the rat aorta model of angiogenesis. Lab Invest. 2000;80:545–555.[Medline] [Order article via Infotrieve]

81. Davis GE, Pintar Allen KA, Salazar R, Maxwell SA. Matrix metalloproteinase-1 and -9 activation by plasmin regulates a novel endothelial cell-mediated mechanism of collagen gel contraction and capillary tube regression in three-dimensional collagen matrices. J Cell Sci. 2001;114:917–930.[Abstract]

82. Lozonschi L, Sunamura M, Kobari M, Egawa S, Ding L, Matsuno S. Controlling tumor angiogenesis and metastasis of C26 murine colon adenocarcinoma by a new matrix metalloproteinase inhibitor, KB-R7785, in two tumor models. Cancer Res. 1999;59:1252–1258.[Abstract/Free Full Text]

83. Maekawa R, Maki H, Yoshida H, Hojo K, Tanaka H, Wada T, Uchida N, Takeda Y, Kasai H, Okamoto H, Tsuzuki H, Kambayashi Y, Watanabe F, Kawada K, Toda K, Ohtani M, Sugita K, Yoshioka T. Correlation of antiangiogenic and antitumor efficacy of N-biphenylsulfonylphenylalanine hydroxamic acid (BPHA), an orally-active, selective matrix metalloproteinase inhibitor. Cancer Res. 1999;59:1231–1235.[Abstract/Free Full Text]

84. Dong Z, Kumar R, Yang X, Fidler IJ. Macrophage-derived metalloelastase is responsible for the generation of angiostatin in Lewis lung carcinoma. Cell. 1997;88:801–810.[Medline] [Order article via Infotrieve]

85. Patterson BC, Sang QA. Angiostatin-converting enzyme activities of human matrilysin (MMP-7) and gelatinase B/type IV collagenase (MMP-9). J Biol Chem. 1997;272:28823–28825.[Abstract/Free Full Text]

86. Cornelius LA, Nehring LC, Harding E, Bolanowski M, Welgus HG, Kobayashi DK, Pierce RA, Shapiro SD. Matrix metalloproteinases generate angiostatin: effects on neovascularization. J Immunol. 1998;161:6845–6852.[Abstract/Free Full Text]

87. Lijnen HR, Ugwu F, Bini A, Collen D. Generation of an angiostatin-like fragment from plasminogen by stromelysin-1 (MMP-3). Biochemistry. 1998;37:4699–4702.[Medline] [Order article via Infotrieve]

88. Pozzi A, Moberg PE, Miles LA, Wagner S, Soloway P, Gardner HA. Elevated matrix metalloproteinase and angiostatin levels in integrin {alpha}1 knockout mice cause reduced tumor vascularization. Proc Natl Acad Sci U S A. 2000;97:2202–2207.[Abstract/Free Full Text]

89. Wen W, Moses MA, Wiederschain D, Arbiser JL, Folkman J. The generation of endostatin is mediated by elastase. Cancer Res. 1999;59:6052–6056.[Abstract/Free Full Text]

90. Felbor U, Dreier L, Bryant RAR, Ploegh HL, Olsen BR, Mothes W. Secreted cathepsin L generates endostatin from collagen XVIII. EMBO J. 2000;19:1187–1194.[Medline] [Order article via Infotrieve]

91. Ferreras M, Felbor U, Lenhard T, Olsen BR, Delaissé JM. Generation and degradation of human endostatin proteins by various proteinases. FEBS Lett. 2000;486:247–251.[Medline] [Order article via Infotrieve]

92. Fang J, Shing Y, Wiederschain D, Yan L, Butterfield C, Jackson G, Harper J, Tamvakopoulos G, Moses MA. Matrix metalloproteinase-2 is required for the switch to the angiogenic phenotype in a tumor model. Proc Natl Acad Sci U S A. 2000;97:3884–3889.[Abstract/Free Full Text]

93. Koivunen E, Arap W, Valtanen H, Rainisalo A, Medina OP, Heikkila P, Kantor C, Gahmberg CG, Salo T, Konttinen YT, Sorsa T, Ruoslahti E, Pasqualini R. Tumor targeting with a selective gelatinase inhibitor. Nat Biotechnol. 1999;17:768–774.[Medline] [Order article via Infotrieve]

94. Kim YM, Jang JW, Lee OH, Yeon J, Choi EY, Kim KW, Lee ST, Kwon YG. Endostatin inhibits endothelial and tumor cellular invasion by blocking the activation and catalytic activity of matrix metalloproteinase 2. Cancer Res. 2000;60:5410–5413.[Abstract/Free Full Text]

95. Bein K, Simons M. Thrombospondin type 1 repeats interact with matrix metalloproteinase 2. J Biol Chem. 2000;275:32167–32173.[Abstract/Free Full Text]

96. Brooks PC, Silletti S, von Schalscha TL, Friedlander M, Cheresh DA. Disruption of angiogenesis by PEX, a noncatalytic metalloproteinase fragment with integrin binding activity. Cell. 1998;92:391–400.[Medline] [Order article via Infotrieve]

97. Pfeifer A, Kessler T, Silletti S, Cheresh DA, Verma IM. Suppression of angiogenesis by lentiviral delivery of PEX, a noncatalytic fragment of matrix metalloproteinase 2. Proc Natl Acad Sci U S A. 2000;97:12227–12232.[Abstract/Free Full Text]

98. Silletti S, Kessler T, Goldberg J, Boger DL, Cheresh DA. Disruption of matrix metalloproteinase 2 binding to integrin {alpha}vß3 by an organic molecule inhibits angiogenesis and tumor growth in vivo. Proc Natl Acad Sci U S A. 2001;98:119–124.[Abstract/Free Full Text]

99. Itoh T, Ikeda T, Gomi H, Nakao S, Suzuki T, Itohara S. Unaltered secretion of ß-amyloid precursor protein in gelatinase A (matrix metalloproteinase 2)-deficient mice. J Biol Chem. 1997;272:22389–22392.[Abstract/Free Full Text]

100. Vu TH, Shipley JM, Bergers G, Berger JE, Helms JA, Hanahan D, Shapiro SD, Senior RM, Werb Z. MMP-9/gelatinase B is a key regulator of growth plate angiogenesis and apoptosis of hypertrophic chondrocytes. Cell. 1998;93:411–422.[Medline] [Order article via Infotrieve]

101. Itoh T, Tanioka M, Yoshida H, Yoshioka T, Nishimoto H, Itohara S. Reduced angiogenesis and tumor progression in gelatinase A-deficient mice. Cancer Res. 1998;58:1048–1051.[Abstract/Free Full Text]

102. Bergers G, Brekken R, McMahon G, Vu TH, Itoh T, Tamaki K, Tanzawa K, Thorpe P, Itohara S, Werb Z, Hanahan D. Matrix metalloproteinase-9 triggers the angiogenic switch during carcinogenesis. Nat Cell Biol. 2000;2:737–744.[Medline] [Order article via Infotrieve]

103. Holmbeck K, Bianco P, Caterina J, Yamada S, Kromer M, Kuznetsov SA, Mankani M, Robey PG, Poole AR, Pidoux I, Ward JM, Birkedal-Hansen H. MT1-MMP-deficient mice develop dwarfism, osteopenia, arthritis, and connective tissue disease due to inadequate collagen turnover. Cell. 1999;99:81–92.[Medline] [Order article via Infotrieve]

104. Zhou Z, Apte SS, Soininen R, Cao R, Baaklini GY, Rauser RW, Wang J, Cao Y, Tryggvason K. Impaired enchondral ossification and angiogenesis in mice deficient in membrane-type matrix metalloproteinase I. Proc Natl Acad Sci U S A. 2000;97:4052–4057.[Abstract/Free Full Text]

105. Collen D. The plasminogen (fibrinolytic) system. Thromb Hemost. 1999;82:259–270.[Medline] [Order article via Infotrieve]

106. Montesano R, Pepper MS, Vassalli JD, Orci L. Phorbol ester induces cultured endothelial cells to invade a fibrin matrix in the presence of fibrinolytic inhibitors. J Cell Physiol. 1987;132:509–516.[Medline] [Order article via Infotrieve]

107. Hiraoka N, Allen E, Apel IJ, Gyetko MR, Weiss SJ. Matrix metalloproteinases regulate neovascularization by acting as pericellular fibrinolysins. Cell. 1998;95:365–377.[Medline] [Order article via Infotrieve]

108. Lelongt B, Bengatta S, Delauche M, Lund LR, Werb Z, Ronco PM. Matrix metalloproteinase 9 protects mice from anti-glomerular basement membrane nephritis through its fibrinolytic activity. J Exp Med. 2001;193:793–802.[Abstract/Free Full Text]

109. Carmeliet P, Collen D. Transgenic mouse models in angiogenesis and cardiovascular disease. J Pathol. 2000;190:387–405.[Medline] [Order article via Infotrieve]

110. Cavallaro U, Tenan M, Castelli V, Perilli A, Maggiano N, Van Meir E, Montesano R, Soria MR, Pepper MS. The response of bovine endothelial cells to FGF-2 and VEGF is dependent on their site of origin: relevance to the regulation of angiogenesis. J Cell Biochem. In press.

111. Pepper MS, Rosnoblet C, Di Sanza C, Kruithof EKO. Synergistic induction of tissue-type plasminogen activator (tPA) by vascular endothelial growth factor and basic fibroblast growth factor and localization of tPA to Weibel-Palade bodies in bovine microvascular endothelial cells. Thromb Hemost. In press.

112. Kroon ME, Koolwijk P, van Der Vecht B, van Hinsbergh VWM. Urokinase receptor expression on human microvascular endothelial cells is increased by hypoxia: implications for capillary-like tube formation in a fibrin matrix. Blood. 2000;96:2775–2783.[Abstract/Free Full Text]

113. Uchiyama T, Kurabayashi M, Ohyama Y, Utsugi T, Akuzawa N, Sato M, Tomono S, Kawazu S, Nagai R. Hypoxia induces transcription of the plasminogen activator inhibitor-1 gene through genistein-sensitive tyrosine kinase pathways in vascular endothelial cells. Arterioscler Thromb Vasc Biol. 2000;20:1155–1161.[Abstract/Free Full Text]

114. Pepper MS, Vassalli J-D, Montesano R, Orci L. Urokinase-type plasminogen activator is induced in migrating capillary endothelial cells. J Cell Biol. 1987;105:2535–2541.[Abstract/Free Full Text]

115. Pepper MS, Sappino A-P, Montesano R, Orci L, Vassalli J-D. Plasminogen activator inhibitor-1 is induced in migrating endothelial cells. J Cell Physiol. 1992;153:129–139.[Medline] [Order article via Infotrieve]

116. Pepper MS, Sappino A-P, Stocklin R, Montesano R, Orci L, Vassalli J-D. Upregulation of urokinase receptor expression on migrating endothelial cells. J Cell Biol. 1993;122:673–684.[Abstract/Free Full Text]

117. Bacharach E, Itin A, Keshet E. Apposition-dependent induction of plasminogen activator inhibitor type-1 expression: a mechanism for balancing pericellular proteolysis during angiogenesis. Blood. 1998;92:939–945.[Abstract/Free Full Text]

118. Pepper MS. Lymphangiogenesis and tumor metastasis: myth or reality. Clin Cancer Res. 2001;7:462–468.[Abstract/Free Full Text]

119. Pepper MS, Wasi S, Ferrara N, Orci L, Montesano R. In vitro angiogenic and proteolytic properties of bovine lymphatic endothelial cells. Exp Cell Res. 1994;210:298–305.[Medline] [Order article via Infotrieve]

120. Pepper MS, Mandriota SJ, Jeltsch M, Kumar V, Alitalo K. Vascular endothelial growth factor (VEGF)-C synergises with basic fibroblast growth factor and VEGF in the induction of angiogenesis in vitro, and alters endothelial cell proteolytic properties. J Cell Physiol. 1998;177:439–452.[Medline] [Order article via Infotrieve]

121. Liu N-F, He Q-L. The regulatory effects of cytokines on lymphatic angiogenesis. Lymphology. 1997;30:3–12.[Medline] [Order article via Infotrieve]

122. Leak LV, Saunders M, Day AA, Jones M. Stimulation of plasminogen activator and inhibitor in the lymphatic endothelium. Microvasc Res. 2000;60:201–211.[Medline] [Order article via Infotrieve]

123. Rømer J, Bugge TH, Pyke C, Lund LR, Flick MJ, Degan LJ, Danø K. Impaired wound healing in mice with a disrupted plasminogen gene. Nat Med. 1996;2:287–292.[Medline] [Order article via Infotrieve]

124. Soff GA, Sanderowitz J, Gately S, Verrusio E, Weiss I, Brem S, Kwaan HC. Expression of plasminogen activator inhibitor type 1 by human prostate carcinoma cells inhibits primary tumor growth, tumor-associated angiogenesis, and metastasis to lung and liver in an athymic mouse model. J Clin Invest. 1995;96:2593–2600.

125. Heymans S, Luttun A, Nuyens D, Theilmeier G, Creemers E, Moons L, Dyspersin GD, Cleutjens JP, Shipley M, Angellilo A, Levi M, Nube O, Baker A, Keshet E, Lupu F, Herbert JM, Smits JF, Shapiro SD, Baes M, Borgers M, Collen D, Daemen MJ, Carmeliet P. Inhibition of plasminogen activators or matrix metalloproteinases prevents cardiac rupture but impairs therapeutic angiogenesis and causes cardiac failure. Nat Med. 1999;5:1135–1142.[Medline] [Order article via Infotrieve]

126. Berman M, Winthrop S, AusprunkD, Rose J, Langer R, Gage J. Plasminogen activator (urokinase) causes vascularization of the cornea. Invest Ophthalmol Vis Sci. 1982;22:191–199.[Abstract/Free Full Text]

127. Goldfarb RH, Ziche M, Murano G, Liotta LA. Plasminogen activators (urokinase) mediate neovascularization: possible role in tumor angiogenesis. Semin Thromb Hemost. 1986;12:337–338.[Medline] [Order article via Infotrieve]

128. Ribatti D, Leali D, Vacca A, Giuliani R, Gualandris A, Roncali L, Nolli ML, Presta M. In vivo angiogenic activity of urokinase: role of endogenous fibroblast growth factor-2. J Cell Sci. 1999;112:4213–4221.[Abstract]

129. Min HY, Doyle LV, Vitt CR, Zandonella L, Stratton-Thomas JR, Shuman MA, Rosenberg S. Urokinase receptor antagonists inhibit angiogenesis and primary tumor growth in syngeneic mice. Cancer Res. 1996;56:2428–2433.[Abstract/Free Full Text]

130. Li H, Lu H, Griscelli F, Opolon P, Sun LQ, Ragot T, Legrand Y, Belin D, Soria J, Soria C, Perricaudet M, Yeh P. Adenovirus-mediated delivery of a uPA/uPAR antagonist suppresses angiogenesis-dependent tumor growth and dissemination in mice. Gene Ther. 1998;5:1105–1113.[Medline] [Order article via Infotrieve]

131. Evans CP, Elfman F, Parangi S, Conn M, Cunha G, Shuman MA. Inhibition of prostate cancer neovascularization and growth by urokinase-plasminogen activator receptor blockade. Cancer Res. 1997;57:3594–3599.[Abstract/Free Full Text]

132. Guo Y, Higazi AA, Arakelian A, Sachais BS, Cines D, Goldfarb RH, Jones TR, Kwaan H, Mazar AP, Rabbani SA. A peptide derived from the nonreceptor binding region of urokinase plasminogen activator (uPA) inhibits tumor progression and angiogenesis and induces tumor cell death in vivo. FASEB J. 2000;14:1400–1410.[Abstract/Free Full Text]

133. Mishima K, Mazar AP, Gown A, Skelly M, Ji XD, Wang XD, Jones TR, Cavenee WK, Huang HJ. A peptide derived from the non-receptor-binding region of urokinase plasminogen activator inhibits glioblastoma growth and angiogenesis in vivo in combination with cisplatin. Proc Natl Acad Sci U S A. 2000;97:8484–8489.[Abstract/Free Full Text]

134. Bajou K, Noel A, Gerard RD, Masson V, Brunner N, Holst-Hansen C, Skobe M, Fusenig NE, Carmeliet P, Collen D, Foidart JM. Absence of host plasminogen activator inhibitor 1 prevents cancer invasion and vascularization. Nat Med. 1998;4:923–928.[Medline] [Order article via Infotrieve]

135. Bajou K, Masson V, Gerard RD, Schmitt PM, Albert V, Praus M, Lund LR, Frandsen TL, Brunner N, Dano K, Fusenig NE, Weidle U, Carmeliet G, Loskutoff D, Collen D, Carmeliet P, Foidart JM, Noël A. The plasminogen activator inhibitor PAI-1 controls in vivo tumor vascularization by interaction with proteases, not vitronectin: implications for antiangiogenic strategies. J Cell Biol. 2001;152:777–784.[Abstract/Free Full Text]

136. Gutierrez LS, Schulman A, Brito-Robinson T, Noria F, Ploplis VA, Castellino FJ. Tumor development is retarded in mice lacking the gene for urokinase-type plasminogen activator or its inhibitor, plasminogen activator inhibitor-1. Cancer Res. 2000;60:5839–5847.[Abstract/Free Full Text]

137. Loskutoff DJ, Curriden SA, Hu G, Deng G. Regulation of cell adhesion by PAI-1. APMIS. 1999;107:54–61.[Medline] [Order article via Infotrieve]

138. Ossowski L, Aguirre-Ghiso JA. Urokinase receptor and integrin partnership: coordination of signalling for cell adhesion, migration and growth. Curr Opin Cell Biol. 2000;12:613–620.[Medline] [Order article via Infotrieve]

139. Preissner KT, Kanse SM, May AE. Urokinase receptor: a molecular organizer in cellular communication. Curr Opin Cell Biol. 2000;12:621–628.[Medline] [Order article via Infotrieve]

140. Stefansson S, Petitclerc E, Wong MK, McMahon GA, Brooks PC, Lawrence DA. Inhibition of angiogenesis in vivo by plasminogen activator inhibitor-1. J Biol Chem. 2001;276:8135–8141.[Abstract/Free Full Text]

141. Levin EG, del Zoppo GJ. Localization of tissue plasminogen activator in the endothelium of a limited number of vessels. Am J Pathol. 1994;144:855–861.[Abstract]

142. Mignatti P, Tsuboi R, Robbins E, Rifkin DB. In vitro angiogenesis on the human amniotic membrane: requirement for basic fibroblast growth factor-induced proteinases. J Cell Biol. 1989;108:671–682.[Abstract/Free Full Text]

143. Yasunaga C, Nakashima Y, Sueishi K. A role of fibrinolytic activity in angiogenesis: quantitative assay using in vitro model. Lab Invest. 1989;61:698–704.[Medline] [Order article via Infotrieve]

144. Sato Y, Okamura K, Morimoto A, Hamanaka R, Hamaguchi K, Shimada T, Ono M, Kohno K, Sakata T, Kuwano M. Indispensable role of tissue-type plasminogen activator in growth factor-dependent tube formation of human microvascular endothelial cells in vitro. Exp Cell Res. 1993;204:223–229.[Medline] [Order article via Infotrieve]

145. Ito K-I, Ryuto M, Ushiro S, Ono M, Sugenoya A, Kuraoka A, Shibata Y, Kuwano M. Expression of tissue-type plasminogen activator and its inhibitor couples with development of capillary network by human microvascular endothelial cells on Matrigel. J Cell Physiol. 1995;162:213–224.[Medline] [Order article via Infotrieve]

146. Schnaper HW, Barnathan ES, Mazar A, Maheshwari S, Ellis S, Cortez SL, Baricos WH, Kleinman HK. Plasminogen activators augment endothelial cell organization in vitro by two distinct pathways. J Cell Physiol. 1995;165:107–118.[Medline] [Order article via Infotrieve]

147. Mawatari M, Okamura K, Matsuda T, Hamanaka R, Mizoguchi H, Higashio K, Kohno K, Kuwano M. Tumor necrosis factor and epidermal growth factor modulate migration of human microvascular endothelial cells and production of tissue-type plasminogen activator and its inhibitor. Exp Cell Res. 1991;192:574–580.[Medline] [Order article via Infotrieve]

148. Zablocki DK, Rade JJ, Alevriadou BR. Adenovirus-mediated expression of tissue plasminogen activator does not alter endothelial cell proliferation and invasion. In Vitro Cell Dev Biol Anim.. 2000;36:625–628.[Medline] [Order article via Infotrieve]

149. Stack MS, Gately S, Bafeti LM, Enghild JJ, Soff GA. Angiostatin inhibits endothelial and melanoma cellular invasion by blocking matrix-enhanced plasminogen activation. Biochem J. 1999;340:77–84.

150. Datta YH, Youssoufian H, Marks PW, Ewenstein BM. Targeting of a heterologous protein to a regulated secretion pathway in cultured endothelial cells. Blood. 1999;94:2696–2703.[Abstract/Free Full Text]

151. Rosnoblet C, Vischer UM, Gerard RD, Irminger JC, Halban PA, Kruithof EKO. Storage of tissue-type plasminogen activator in Weibel-Palade bodies of human endothelial cells. Arterioscler Thromb Vasc Biol. 1999;19:1796–1803.[Abstract/Free Full Text]

152. Taraboletti G, Sonzogni L, Vergani V, Hosseini G, Ceruti R, Ghilardi C, Bastone A, Toschi E, Borsotti P, Scanziani E, Giavazzi R, Pepper MS, Stetler-Stevenson WG, Bani MR. Posttranscriptional stimulation of endothelial cell matrix metalloproteinases 2 and 1 by endothelioma cells. Exp Cell Res. 2000;258:384–394.[Medline] [Order article via Infotrieve]

153. Pepper MS, Tacchini-Cottier F, Sabapathy K, Montesano R, Wagner EF. Endothelial cells transformed by polyomavirus middle T oncogene: a model for hemangiomas and other vascular tumours. In: Bicknell R, Lewis CE, Ferrara N, eds. Tumour Angiogenesis. Oxford, England: Oxford University Press; 1997:309–331.

154. Taraboletti G, Belotti D, Dejana E, Mantovani A, Giavazzi R. Endothelial cell migration and invasiveness are induced by a soluble factor produced by murine endothelioma cells transformed by polyoma virus middle T oncogene. Cancer Res. 1993;53:3812–3816.[Abstract/Free Full Text]

155. Vergani V, Garofalo A, Bani MR, Borsotti P, Parker MP, Drudis T, Mazzarol G, Viale G, Giavazzi R, Stetler-Stevenson WG, Taraboletti G. Inhibition of matrix metalloproteinases by over-expression of tissue inhibitor of metalloproteinase-2 inhibits the growth of experimental hemangiomas. Int J Cancer. 2001;91:241–247.[Medline] [Order article via Infotrieve]

156. Taraboletti G, Garofalo A, Belotti D, Drudis T, Borsotti P, Scanziani E, Brown PD, Giavazzi R. Inhibition of angiogenesis and murine hemangioma growth by Batimastat, a synthetic inhibitor of matrix metalloproteinases. J Natl Cancer Inst. 1995;87:293–298.[Abstract/Free Full Text]

157. Dubois-Stringfellow N, Jonczyk J, Bautch VL. Perturbations in the fibrinolytic pathway abolish cyst formation but not capillary-like organization of cultured murine endothelial cells. Blood. 1994;83:3206–3217.[Abstract/Free Full Text]

158. Besser D, Urich M, Sakaue M, Messerschmitt A, Ballmer-Hofer K, Nagamine Y. Urokinase-type plasminogen activator gene regulation by polyomavirus middle-T antigen. Oncogene. 1995;11:2383–2391.[Medline] [Order article via Infotrieve]

159. Primo L, Roca C, Ferrandi C, Lanfrancone L, Bussolino F. Human endothelial cells expressing polyoma middle T induce tumors. Oncogene. 2000;19:3632–3641.[Medline] [Order article via Infotrieve]

160. Sabapathy KT, Pepper MS, Kiefer F, Möhle-Steinlein U, Tacchini-Cottier F, Fetka I, Breier G, Carmeliet P, Risau W, Montesano R, Wagner EF. Polyoma middle T-induced vascular tumor formation: the role of the plasminogen activator/plasmin system. J Cell Biol. 1997;137:953–963.[Abstract/Free Full Text]

161. Lijnen HR, Wagner EF, Collen D. Plasminogen-dependent and -independent proteolytic activity of murine endothelioma cells with targeted inactivation of fibrinolytic genes. Thromb Hemost. 1997;77:362–367.[Medline] [Order article via Infotrieve]

162. Griffioen AW, Molema G. Angiogenesis: potentials for pharmacologic intervention in the treatment of cancer, cardiovascular diseases, and chronic inflammation. Pharmacol Rev. 2000;52:237–268.[Abstract/Free Full Text]

163. Brown PD. Clinical studies with matrix metalloproteinase inhibitors. APMIS. 1999;107:174–180.[Medline] [Order article via Infotrieve]

164. Hidalgo M, Eckhardt SG. Development of matrix metalloproteinase inhibitors in cancer therapy. J Natl Cancer Inst. 2001;93:178–193.[Abstract/Free Full Text]

165. Zucker S, Cao J, Chen WT. Critical appraisal of the use of matrix metalloproteinase inhibitors in cancer treatment. Oncogene. 2000;19:6642–6650.[Medline] [Order article via Infotrieve]

166. Kruger A, Soeltl R, Sopov I, Kopitz C, Arlt M, Magdolen V, Harbeck N, Gansbacher B, Schmitt M. Hydroxamate-type matrix metalloproteinase inhibitor batimastat promotes liver metastasis. Cancer Res. 2001;61:1272–1275.[Abstract/Free Full Text]

167. Jiang Y, Wang M, Celiker MY, Liu YE, Sang QXA, Goldberg ID, Shi YE. Stimulation of mammary tumorigenesis by systemic tissue inhibitor of matrix metalloproteinase 4 gene delivery. Cancer Res. 2001;61:2365–2370.[Abstract/Free Full Text]

168. Eatock MM, Schätzlein A, Kaye SB. Tumour vasculature as a target for anticancer therapy. Cancer Treatment Rev. 2000;26:191–204.[Medline] [Order article via Infotrieve]

169. Mandriota SJ, Pepper MS. Vascular endothelial growth factor-induced in vitro angiogenesis and plasminogen activator expression are dependent on endogenous basic fibroblast growth factor. J Cell Sci. 1997;110:2293–2302.[Abstract]




This article has been cited by other articles:


Home page
IOVSHome page
A. Basu, G. Menicucci, J. Maestas, A. Das, and P. McGuire
Plasminogen Activator Inhibitor-1 (PAI-1) Facilitates Retinal Angiogenesis in a Model of Oxygen-Induced Retinopathy
Invest. Ophthalmol. Vis. Sci., October 1, 2009; 50(10): 4974 - 4981.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Cell Physiol.Home page
A. C. Aplin, W. H. Zhu, E. Fogel, and R. F. Nicosia
Vascular regression and survival are differentially regulated by MT1-MMP and TIMPs in the aortic ring model of angiogenesis
Am J Physiol Cell Physiol, August 1, 2009; 297(2): C471 - C480.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
H. Lukkarinen, A. Hogmalm, U. Lappalainen, and K. Bry
Matrix Metalloproteinase-9 Deficiency Worsens Lung Injury in a Model of Bronchopulmonary Dysplasia
Am. J. Respir. Cell Mol. Biol., July 1, 2009; 41(1): 59 - 68.
[Abstract] [Full Text] [PDF]


Home page
Anticancer ResHome page
D. W. SIEMANN, C. M. NORRIS, A. RYAN, and W. SHI
Impact of Tumor Cell VEGF Expression on the In Vivo Efficacy of Vandetanib (ZACTIMATM; ZD6474)
Anticancer Res, June 1, 2009; 29(6): 1987 - 1992.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. ProteomicsHome page
T. Vaisar, S. Y. Kassim, I. G. Gomez, P. S. Green, S. Hargarten, P. J. Gough, W. C. Parks, C. L. Wilson, E. W. Raines, and J. W. Heinecke
MMP-9 Sheds the {beta}2 Integrin Subunit (CD18) from Macrophages
Mol. Cell. Proteomics, May 1, 2009; 8(5): 1044 - 1060.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
O. A. Stone, C. Richer, C. Emanueli, V. van Weel, P. H.A. Quax, R. Katare, N. Kraenkel, P. Campagnolo, L. S. Barcelos, M. Siragusa, et al.
Critical Role of Tissue Kallikrein in Vessel Formation and Maturation: Implications for Therapeutic Revascularization
Arterioscler Thromb Vasc Biol, May 1, 2009; 29(5): 657 - 664.
[Abstract] [Full Text] [PDF]


Home page
Ann Rheum DisHome page
L Oslejskova, M Grigorian, S Gay, M Neidhart, and L Senolt
The metastasis associated protein S100A4: a potential novel link to inflammation and consequent aggressive behaviour of rheumatoid arthritis synovial fibroblasts
Ann Rheum Dis, November 1, 2008; 67(11): 1499 - 1504.
[Abstract] [Full Text] [PDF]


Home page
Innate ImmunityHome page
C. Guruvayoorappan and G. Kuttan
(+)-Catechin inhibits tumour angiogenesis and regulates the production of nitric oxide and TNF-{alpha} in LPS-stimulated macrophages
Innate Immunity, June 1, 2008; 14(3): 160 - 174.
[Abstract] [PDF]


Home page
Arch OphthalmolHome page
I. A. Bhutto, K. Uno, C. Merges, L. Zhang, D. S. McLeod, and G. A. Lutty
Reduction of Endogenous Angiogenesis Inhibitors in Bruch's Membrane of the Submacular Region in Eyes With Age-Related Macular Degeneration
Arch Ophthalmol, May 1, 2008; 126(5): 670 - 678.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
C. Consoli, E. Martelli, M. D'Adamo, R. Menghini, D. Arcelli, O. Porzio, A. Pandolfi, G. R. Pistolese, A. Consoli, R. Lauro, et al.
Insulin Resistance Affects Gene Expression in Endothelium
Arterioscler Thromb Vasc Biol, February 1, 2008; 28(2): e7 - e9.
[Full Text] [PDF]


Home page
Am. J. Clin. Nutr.Home page
L. Jensen, B. Sloth, I. Krog-Mikkelsen, A. Flint, A. Raben, T. Tholstrup, N. Brunner, and A. Astrup
A low-glycemic-index diet reduces plasma plasminogen activator inhibitor-1 activity, but not tissue inhibitor of proteinases-1 or plasminogen activator inhibitor-1 protein, in overweight women
Am. J. Clinical Nutrition, January 1, 2008; 87(1): 97 - 105.
[Abstract] [Full Text] [PDF]


Home page
Mol Hum ReprodHome page
M. Plaisier, P. Koolwijk, F. Willems, F. M. Helmerhorst, and V. W.M. van Hinsbergh
Pericellular-acting proteases in human first trimester decidua
Mol. Hum. Reprod., January 1, 2008; 14(1): 41 - 51.
[Abstract] [Full Text] [PDF]


Home page
Reproductive SciencesHome page
L. K. Harris and J. D. Aplin
Vascular Remodeling and Extracellular Matrix Breakdown in the Uterine Spiral Arteries During Pregnancy
Reproductive Sciences, December 1, 2007; 14(8_suppl): 28 - 34.
[Abstract] [PDF]


Home page
Am. J. Physiol. Heart Circ. Physiol.Home page
L. Krishnan, J. B. Hoying, H. Nguyen, H. Song, and J. A. Weiss
Interaction of angiogenic microvessels with the extracellular matrix
Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3650 - H3658.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
M. A. Zayed, W. Yuan, T. M. Leisner, D. Chalothorn, A. W. McFadden, M. D. Schaller, M. E. Hartnett, J. E. Faber, and L. V. Parise
CIB1 Regulates Endothelial Cells and Ischemia-Induced Pathological and Adaptive Angiogenesis
Circ. Res., November 26, 2007; 101(11): 1185 - 1193.
[Abstract] [Full Text] [PDF]


Home page
FASEB J.Home page
D. Belloni, S. Scabini, C. Foglieni, L. Veschini, A. Giazzon, B. Colombo, A. Fulgenzi, K. B. Helle, M. E. Ferrero, A. Corti, et al.
The vasostatin-I fragment of chromogranin A inhibits VEGF-induced endothelial cell proliferation and migration
FASEB J, October 1, 2007; 21(12): 3052 - 3062.
[Abstract] [Full Text] [PDF]


Home page
Hum ReprodHome page
J. Gilabert-Estelles, L.A. Ramon, F. Espana, J. Gilabert, V. Vila, E. Reganon, R. Castello, M. Chirivella, and A. Estelles
Expression of angiogenic factors in endometriosis: relationship to fibrinolytic and metalloproteinase systems
Hum. Reprod., August 1, 2007; 22(8): 2120 - 2127.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Gastrointest. Liver Physiol.Home page
J. H. Chidlow Jr., D. Shukla, M. B. Grisham, and C. G. Kevil
Pathogenic angiogenesis in IBD and experimental colitis: new ideas and therapeutic avenues
Am J Physiol Gastrointest Liver Physiol, July 1, 2007; 293(1): G5 - G18.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
N. E. Vlahakis, B. A. Young, A. Atakilit, A. E. Hawkridge, R. B. Issaka, N. Boudreau, and D. Sheppard
Integrin {alpha}9beta1 Directly Binds to Vascular Endothelial Growth Factor (VEGF)-A and Contributes to VEGF-A-induced Angiogenesis
J. Biol. Chem., May 18, 2007; 282(20): 15187 - 15196.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
L. Ivanciu, R. D. Gerard, H. Tang, F. Lupu, and C. Lupu
Adenovirus-Mediated Expression of Tissue Factor Pathway Inhibitor-2 Inhibits Endothelial Cell Migration and Angiogenesis
Arterioscler Thromb Vasc Biol, February 1, 2007; 27(2): 310 - 316.
[Abstract] [Full Text] [PDF]


Home page
Physiol. Rev.Home page
K. J. Greenlee, Z. Werb, and F. Kheradmand
Matrix Metalloproteinases in Lung: Multiple, Multifarious, and Multifaceted
Physiol Rev, January 1, 2007; 87(1): 69 - 98.
[Abstract] [Full Text] [PDF]


Home page
EndocrinologyHome page
E. J. Mead, J. J. Maguire, R. E. Kuc, and A. P. Davenport
Kisspeptins Are Novel Potent Vasoconstrictors in Humans, with a Discrete Localization of Their Receptor, G Protein-Coupled Receptor 54, to Atherosclerosis-Prone Vessels
Endocrinology, January 1, 2007; 148(1): 140 - 147.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
A. H. Licht, O. T. Pein, L. Florin, B. Hartenstein, H. Reuter, B. Arnold, P. Lichter, P. Angel, and M. Schorpp-Kistner
JunB is required for endothelial cell morphogenesis by regulating core-binding factor {beta}
J. Cell Biol., December 18, 2006; 175(6): 981 - 991.
[Abstract] [Full Text] [PDF]


Home page
Molecular Cancer TherapeuticsHome page
P.-Y. Ho, W.-B. Zhong, Y.-S. Ho, and W.-S. Lee
Terbinafine inhibits endothelial cell migration through suppression of the Rho-mediated pathway
Mol. Cancer Ther., December 1, 2006; 5(12): 3130 - 3138.
[Abstract] [Full Text] [PDF]


Home page
Clin. Cancer Res.Home page
X. Zhang, X.-O. Shu, Q. Cai, Z. Ruan, Y.-T. Gao, and W. Zheng
Functional plasminogen activator inhibitor-1 gene variants and breast cancer survival.
Clin. Cancer Res., October 15, 2006; 12(20): 6037 - 6042.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
W. B. Saunders, B. L. Bohnsack, J. B. Faske, N. J. Anthis, K. J. Bayless, K. K. Hirschi, and G. E. Davis
Coregulation of vascular tube stabilization by endothelial cell TIMP-2 and pericyte TIMP-3
J. Cell Biol., October 9, 2006; 175(1): 179 - 191.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
J. R. van Beijnum, R. P. Dings, E. van der Linden, B. M. M. Zwaans, F. C. S. Ramaekers, K. H. Mayo, and A. W. Griffioen
Gene expression of tumor angiogenesis dissected: specific targeting of colon cancer angiogenic vasculature
Blood, October 1, 2006; 108(7): 2339 - 2348.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
J. Herrmann, L. O. Lerman, D. Mukhopadhyay, C. Napoli, and A. Lerman
Angiogenesis in Atherogenesis
Arterioscler Thromb Vasc Biol, September 1, 2006; 26(9): 1948 - 1957.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
G. Zhang, R. G. Fahmy, N. diGirolamo, and L. M. Khachigian
JUN siRNA regulates matrix metalloproteinase-2 expression, microvascular endothelial growth and retinal neovascularisation
J. Cell Sci., August 1, 2006; 119(15): 3219 - 3226.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
G. Ghersi, Q. Zhao, M. Salamone, Y. Yeh, S. Zucker, and W.-T. Chen
The Protease Complex Consisting of Dipeptidyl Peptidase IV and Seprase Plays a Role in the Migration and Invasion of Human Endothelial Cells in Collagenous Matrices.
Cancer Res., May 1, 2006; 66(9): 4652 - 4661.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
J. L. Jadrich, M. B. O'Connor, and E. Coucouvanis
The TGF{beta} activated kinase TAK1 regulates vascular development in vivo.
Development, April 1, 2006; 133(8): 1529 - 1541.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
V. W.M. van Hinsbergh, M. A. Engelse, and P. H.A. Quax
Pericellular Proteases in Angiogenesis and Vasculogenesis
Arterioscler Thromb Vasc Biol, April 1, 2006; 26(4): 716 - 728.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. J. Post, K. Sato, M. Murakami, J. Bao, D. Tirziu, J. D. Pearlman, and M. Simons
Adenoviral PR39 improves blood flow and myocardial function in a pig model of chronic myocardial ischemia by enhancing collateral formation
Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R494 - R500.
[Abstract] [Full Text] [PDF]


Home page
EndocrinologyHome page
S. Feng, N. V. Bogatcheva, A. A. Kamat, A. Truong, and A. I. Agoulnik
Endocrine Effects of Relaxin Overexpression in Mice
Endocrinology, January 1, 2006; 147(1): 407 - 414.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
A. Zijlstra, M. Seandel, T. A. Kupriyanova, J. J. Partridge, M. A. Madsen, E. A. Hahn-Dantona, J. P. Quigley, and E. I. Deryugina
Proangiogenic role of neutrophil-like inflammatory heterophils during neovascularization induced by growth factors and human tumor cells
Blood, January 1, 2006; 107(1): 317 - 327.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
G. E. Davis and D. R. Senger
Endothelial Extracellular Matrix: Biosynthesis, Remodeling, and Functions During Vascular Morphogenesis and Neovessel Stabilization
Circ. Res., November 25, 2005; 97(11): 1093 - 1107.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
U. R. Pendurthi, T. T. Tran, M. Post, and L. V. M. Rao
Proteolysis of CCN1 by Plasmin: Functional Implications
Cancer Res., November 1, 2005; 65(21): 9705 - 9711.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
C.-L. E. Helm, M. E. Fleury, A. H. Zisch, F. Boschetti, and M. A. Swartz
Synergy between interstitial flow and VEGF directs capillary morphogenesis in vitro through a gradient amplification mechanism
PNAS, November 1, 2005; 102(44): 15779 - 15784.
[Abstract] [Full Text] [PDF]


Home page
StrokeHome page
Y. Zhu, C. Lee, F. Shen, R. Du, W. L. Young, and G.-Y. Yang
Angiopoietin-2 Facilitates Vascular Endothelial Growth Factor-Induced Angiogenesis in the Mature Mouse Brain
Stroke, July 1, 2005; 36(7): 1533 - 1537.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
A. Garcia-Touchard, T. D. Henry, G. Sangiorgi, L. G. Spagnoli, A. Mauriello, C. Conover, and R. S. Schwartz
Extracellular Proteases in Atherosclerosis and Restenosis
Arterioscler Thromb Vasc Biol, June 1, 2005; 25(6): 1119 - 1127.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
W. B. Saunders, K. J. Bayless, and G. E. Davis
MMP-1 activation by serine proteases and MMP-10 induces human capillary tubular network collapse and regression in 3D collagen matrices
J. Cell Sci., May 15, 2005; 118(10): 2325 - 2340.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
C.-S. Shi, G.-Y. Shi, Y.-S. Chang, H.-S. Han, C.-H. Kuo, C. Liu, H.-C. Huang, Y.-J. Chang, P.-S. Chen, and H.-L. Wu
Evidence of Human Thrombomodulin Domain as a Novel Angiogenic Factor
Circulation, April 5, 2005; 111(13): 1627 - 1636.
[Abstract] [Full Text] [PDF]


Home page
JCOHome page
G. Gasparini, R. Longo, M. Fanelli, and B. A. Teicher
Combination of Antiangiogenic Therapy With Other Anticancer Therapies: Results, Challenges, and Open Questions
J. Clin. Oncol., February 20, 2005; 23(6): 1295 - 1311.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
N. E. Vlahakis, B. A. Young, A. Atakilit, and D. Sheppard
The Lymphangiogenic Vascular Endothelial Growth Factors VEGF-C and -D Are Ligands for the Integrin {alpha}9{beta}1
J. Biol. Chem., February 11, 2005; 280(6): 4544 - 4552.
[Abstract] [Full Text] [PDF]


Home page
Physiol. Rev.Home page
A. C. Newby
Dual Role of Matrix Metalloproteinases (Matrixins) in Intimal Thickening and Atherosclerotic Plaque Rupture
Physiol Rev, January 1, 2005; 85(1): 1 - 31.
[Abstract] [Full Text] [PDF]


Home page
Arch OphthalmolHome page
A. Das, N. Boyd, T. R. Jones, N. Talarico, and P. G. McGuire
Inhibition of Choroidal Neovascularization by a Peptide Inhibitor of the Urokinase Plasminogen Activator and Receptor System in a Mouse Model
Arch Ophthalmol, December 1, 2004; 122(12): 1844 - 1849.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
T.-H. Chun, F. Sabeh, I. Ota, H. Murphy, K. T. McDonagh, K. Holmbeck, H. Birkedal-Hansen, E. D. Allen, and S. J. Weiss
MT1-MMP-dependent neovessel formation within the confines of the three-dimensional extracellular matrix
J. Cell Biol., November 22, 2004; 167(4): 757 - 767.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Endocrinol. Metab.Home page
M. Plaisier, K. Kapiteijn, P. Koolwijk, C. Fijten, R. Hanemaaijer, J. M. Grimbergen, A. Mulder-Stapel, P. H. A. Quax, F. M. Helmerhorst, and V. W. M. van Hinsbergh
Involvement of Membrane-Type Matrix Metalloproteinases (MT-MMPs) in Capillary Tube Formation by Human Endometrial Microvascular Endothelial Cells: Role of MT3-MMP
J. Clin. Endocrinol. Metab., November 1, 2004; 89(11): 5828 - 5836.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Heart Circ. Physiol.Home page
D. Wang, O. A. Carretero, X.-Y. Yang, N.-E. Rhaleb, Y.-H. Liu, T.-D. Liao, and X.-P. Yang
N-acetyl-seryl-aspartyl-lysyl-proline stimulates angiogenesis in vitro and in vivo
Am J Physiol Heart Circ Physiol, November 1, 2004; 287(5): H2099 - H2105.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
L. K. Chang, G. Garcia-Cardena, F. Farnebo, M. Fannon, E. J. Chen, C. Butterfield, M. A. Moses, R. C. Mulligan, J. Folkman, and A. Kaipainen
Dose-dependent response of FGF-2 for lymphangiogenesis
PNAS, August 10, 2004; 101(32): 11658 - 11663.
[Abstract] [Full Text] [PDF]


Home page
IOVSHome page
S. Hughes and T. Chan-Ling
Characterization of Smooth Muscle Cell and Pericyte Differentiation in the Rat Retina In Vivo
Invest. Ophthalmol. Vis. Sci., August 1, 2004; 45(8): 2795 - 2806.
[Abstract] [Full Text] [PDF]


Home page
GutHome page
V M Diaz, M Hurtado, T M Thomson, J Reventos, and R Paciucci
Specific interaction of tissue-type plasminogen activator (t-PA) with annexin II on the membrane of pancreatic cancer cells activates plasminogen and promotes invasion in vitro
Gut, July 1, 2004; 53(7): 993 - 1000.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Pathol.Home page
R. E. Nisato, J. A. Harrison, R. Buser, L. Orci, C. Rinsch, R. Montesano, P. Dupraz, and M. S. Pepper
Generation and Characterization of Telomerase-Transfected Human Lymphatic Endothelial Cells with an Extended Life Span
Am. J. Pathol., July 1, 2004; 165(1): 11 - 24.
[Abstract] [Full Text] [PDF]


Home page
Clin. Cancer Res.Home page
W.-H. Yoon, Y.-J. Jung, T.-D. Kim, G. Li, B.-J. Park, J.-Y. Kim, Y.-C. Lee, J.-M. Kim, J.-I. Park, H.-D. Park, et al.
Gabexate Mesilate Inhibits Colon Cancer Growth, Invasion, and Metastasis by Reducing Matrix Metalloproteinases and Angiogenesis
Clin. Cancer Res., July 1, 2004; 10(13): 4517 - 4526.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
A. Zijlstra, R. T. Aimes, D. Zhu, K. Regazzoni, T. Kupriyanova, M. Seandel, E. I. Deryugina, and J. P. Quigley
Collagenolysis-dependent Angiogenesis Mediated by Matrix Metalloproteinase-13 (Collagenase-3)
J. Biol. Chem., June 25, 2004; 279(26): 27633 - 27645.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
G. W. Prager, J. M. Breuss, S. Steurer, D. Olcaydu, J. Mihaly, P. M. Brunner, H. Stockinger, and B. R. Binder
Vascular Endothelial Growth Factor Receptor-2-Induced Initial Endothelial Cell Migration Depends on the Presence of the Urokinase Receptor
Circ. Res., June 25, 2004; 94(12): 1562 - 1570.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Pathol.Home page
A Noel, C Maillard, N Rocks, M Jost, V Chabottaux, N E Sounni, E Maquoi, D Cataldo, and J M Foidart
Membrane associated proteases and their inhibitors in tumour angiogenesis
J. Clin. Pathol., June 1, 2004; 57(6): 577 - 584.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Pathol.Home page
A H G Hansma, Y van Hensbergen, B C Kuenen, P J van Diest, R Hanemaaijer, S Meijer, H M Pinedo, and K Hoekman
A patient with a VEGF and endostatin producing gastrointestinal autonomic nerve tumour
J. Clin. Pathol., May 1, 2004; 57(5): 536 - 538.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Pathol.Home page
A. Agarwal, U. Munoz-Najar, U. Klueh, S.-C. Shih, and K. P. Claffey
N-Acetyl-Cysteine Promotes Angiostatin Production and Vascular Collapse in an Orthotopic Model of Breast Cancer
Am. J. Pathol., May 1, 2004; 164(5): 1683 - 1696.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
B. Hou, M. Eren, C. A. Painter, J. W. Covington, J. D. Dixon, J. A. Schoenhard, and D. E. Vaughan
Tumor Necrosis Factor {alpha} Activates the Human Plasminogen Activator Inhibitor-1 Gene through a Distal Nuclear Factor {kappa}B Site
J. Biol. Chem., April 30, 2004; 279(18): 18127 - 18136.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
M. Ehrbar, V. G. Djonov, C. Schnell, S. A. Tschanz, G. Martiny-Baron, U. Schenk, J. Wood, P. H. Burri, J. A. Hubbell, and A. H. Zisch
Cell-Demanded Liberation of VEGF121 From Fibrin Implants Induces Local and Controlled Blood Vessel Growth
Circ. Res., April 30, 2004; 94(8): 1124 - 1132.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
S. Langlois, D. Gingras, and R. Beliveau
Membrane type 1-matrix metalloproteinase (MT1-MMP) cooperates with sphingosine 1-phosphate to induce endothelial cell migration and morphogenic differentiation
Blood, April 15, 2004; 103(8): 3020 - 3028.
[Abstract] [Full Text] [PDF]


Home page
Sci Aging Knowl EnvironHome page
M. J. Reed and J. M. Edelberg
Impaired Angiogenesis in the Aged
Sci. Aging Knowl. Environ., February 18, 2004; 2004(7): pe7 - 7.
[Abstract] [Full Text]


Home page
Circ. Res.Home page
M. P. Bendeck
Macrophage Matrix Metalloproteinase-9 Regulates Angiogenesis in Ischemic Muscle
Circ. Res., February 6, 2004; 94(2): 138 - 139.
[Full Text] [PDF]


Home page
Circ. Res.Home page
C. Johnson, H.-J. Sung, S. M. Lessner, M. E. Fini, and Z. S. Galis
Matrix Metalloproteinase-9 Is Required for Adequate Angiogenic Revascularization of Ischemic Tissues: Potential Role in Capillary Branching
Circ. Res., February 6, 2004; 94(2): 262 - 268.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
G. W. Prager, J. M. Breuss, S. Steurer, J. Mihaly, and B. R. Binder
Vascular endothelial growth factor (VEGF) induces rapid prourokinase (pro-uPA) activation on the surface of endothelial cells
Blood, February 1, 2004; 103(3): 955 - 962.
[Abstract] [Full Text] [PDF]


Home page
J. Histochem. Cytochem.Home page
A. N. Witmer, B. C. van Blijswijk, C. J.F. van Noorden, G. F.J.M. Vrensen, and R. O. Schlingemann
In Vivo Angiogenic Phenotype of Endothelial Cells and Pericytes Induced by Vascular Endothelial Growth Factor-A
J. Histochem. Cytochem., January 1, 2004; 52(1): 39 - 52.
[Abstract] [Full Text] [PDF]


Home page
IOVSHome page
I. J. Suner, D. G. Espinosa-Heidmann, M. E. Marin-Castano, E. P. Hernandez, S. Pereira-Simon, and S. W. Cousins
Nicotine Increases Size and Severity of Experimental Choroidal Neovascularization
Invest. Ophthalmol. Vis. Sci., January 1, 2004; 45(1): 311 - 317.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
H. Solberg, J. Rinkenberger, K. Dano, Z. Werb, and L. R. Lund
A functional overlap of plasminogen and MMPs regulates vascularization during placental development
Development, September 15, 2003; 130(18): 4439 - 4450.
[Abstract] [Full Text] [PDF]


Home page
SEMIN CARDIOTHORAC VASC ANESTHHome page
V. Chhokar and A. L. Tucker
Angiogenesis: Basic Mechanisms and Clinical Applications
Seminars in Cardiothoracic and Vascular Anesthesia, September 1, 2003; 7(3): 253 - 280.
[Abstract] [PDF]


Home page
Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
T. Koike, R. B. Vernon, M. D. Gooden, E. Sadoun, and M. J. Reed
Inhibited Angiogenesis in Aging: A Role for TIMP-2
J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2003; 58(9): B798 - 805.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
J. Sturge, D. Wienke, L. East, G. E. Jones, and C. M. Isacke
GPI-anchored uPAR requires Endo180 for rapid directional sensing during chemotaxis
J. Cell Biol., September 1, 2003; 162(5): 789 - 794.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
M. Buchholz, A. Biebl, A. Neesse, M. Wagner, T. Iwamura, G. Leder, G. Adler, and T. M. Gress
SERPINE2 (Protease Nexin I) Promotes Extracellular Matrix Production and Local Invasion of Pancreatic Tumors in Vivo
Cancer Res., August 15, 2003; 63(16): 4945 - 4951.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
M. L. Ponce, S. Hibino, A. M. Lebioda, M. Mochizuki, M. Nomizu, and H. K. Kleinman
Identification of a Potent Peptide Antagonist to an Active Laminin-1 Sequence That Blocks Angiogenesis and Tumor Growth
Cancer Res., August 15, 2003; 63(16): 5060 - 5064.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Pathol.Home page
S. Chuang-Tsai, T. H. Sisson, N. Hattori, C. G. Tsai, N. M. Subbotina, K. E. Hanson, and R. H. Simon
Reduction in Fibrotic Tissue Formation in Mice Genetically Deficient in Plasminogen Activator Inhibitor-1
Am. J. Pathol., August 1, 2003; 163(2): 445 - 452.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
M. L. Cher, H. R. Biliran Jr., S. Bhagat, Y. Meng, M. Che, J. Lockett, J. Abrams, R. Fridman, M. Zachareas, and S. Sheng
Maspin expression inhibits osteolysis, tumor growth, and angiogenesis in a model of prostate cancer bone metastasis
PNAS, June 24, 2003; 100(13): 7847 - 7852.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
K. Kallenbach, H. A. Fernandez, G. Seghezzi, F. G. Baumann, S. Patel, E. A. Grossi, A. C. Galloway, and P. Mignatti
A Quantitative In Vitro Model of Smooth Muscle Cell Migration Through the Arterial Wall Using the Human Amniotic Membrane
Arterioscler Thromb Vasc Biol, June 1, 2003; 23(6): 1008 - 1013.
[Abstract] [Full Text] [PDF]


Home page
IOVSHome page
J.-M. Rakic, V. Lambert, C. Munaut, K. Bajou, K. Peyrollier, M.-L. Alvarez-Gonzalez, P. Carmeliet, J.-M. Foidart, and A. Noel
Mice without uPA, tPA, or Plasminogen Genes Are Resistant to Experimental Choroidal Neovascularization
Invest. Ophthalmol. Vis. Sci., April 1, 2003; 44(4): 1732 - 1739.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
P. E. Rakoczy, M. Brankov, A. Fonceca, T. Zaknich, B. C. Rae, and C.-M. Lai
Enhanced Recombinant Adeno-Associated Virus-Mediated Vascular Endothelial Growth Factor Expression in the Adult Mouse Retina: A Potential Model for Diabetic Retinopathy
Diabetes, March 1, 2003; 52(3): 857 - 863.
[Abstract] [Full Text] [PDF]


Home page
Eur Heart JHome page
P.O Bonetti, L.O Lerman, C Napoli, and A Lerman
Statin effects beyond lipid lowering--are they clinically relevant?
Eur. Heart J., February 1, 2003; 24(3): 225 - 248.
[Full Text] [PDF]


Home page
IOVSHome page
L. Berglin, S. Sarman, I. van der Ploeg, B. Steen, Y. Ming, S. Itohara, S. Seregard, and A. Kvanta
Reduced Choroidal Neovascular Membrane Formation in Matrix Metalloproteinase-2-Deficient Mice
Invest. Ophthalmol. Vis. Sci., January 1, 2003; 44(1): 403 - 408.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Pathol.Home page
V. Lambert, C. Munaut, M. Jost, A. Noel, Z. Werb, J.-M. Foidart, and J.-M. Rakic
Matrix Metalloproteinase-9 Contributes to Choroidal Neovascularization
Am. J. Pathol., October 1, 2002; 161(4): 1247 - 1253.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
J. C. Juarez, X. Guan, N. V. Shipulina, M. L. Plunkett, G. C. Parry, D. E. Shaw, J.-C. Zhang, S. A. Rabbani, K. R. McCrae, A. P. Mazar, et al.
Histidine-Proline-rich Glycoprotein Has Potent Antiangiogenic Activity Mediated through the Histidine-Proline-rich Domain
Cancer Res., September 15, 2002; 62(18): 5344 - 5350.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
U. R. Pendurthi, M. Ngyuen, P. Andrade-Gordon, L. C. Petersen, and L. V. M. Rao
Plasmin Induces Cyr61 Gene Expression in Fibroblasts Via Protease-Activated Receptor-1 and p44/42 Mitogen-Activated Protein Kinase-Dependent Signaling Pathway
Arterioscler Thromb Vasc Biol, September 1, 2002; 22(9): 1421 - 1426.
[Abstract] [Full Text] [PDF]


Home page
IOVSHome page
S. Sakurai, S. Alam, G. Pagan-Mercado, F. Hickman, J.-Y. Tsai, P. Zelenka, and S. Sato
Retinal Capillary Pericyte Proliferation and c-Fos mRNA Induction by Prostaglandin D2 through the cAMP Response Element
Invest. Ophthalmol. Vis. Sci., August 1, 2002; 43(8): 2774 - 2781.
[Abstract] [Full Text] [PDF]


Home page
Cell Growth Differ.Home page
A. R. Farina, M.-P. Masciulli, A. Tacconelli, L. Cappabianca, G. De Santis, A. Gulino, and A. R. Mackay
All-trans-Retinoic Acid Induces Nuclear Factor {kappa}B Activation and Matrix Metalloproteinase-9 Expression and Enhances Basement Membrane Invasivity of Differentiation-resistant Human SK-N-BE 9N Neuroblastoma Cells
Cell Growth Differ., August 1, 2002; 13(8): 343 - 354.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
A. G. Polson, D. Wang, J. DeRisi, and D. Ganem
Modulation of Host Gene Expression by the Constitutively Active G Protein-coupled Receptor of Kaposi's Sarcoma-associated Herpesvirus
Cancer Res., August 1, 2002; 62(15): 4525 - 4530.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
B. H. Rauch, E. Bretschneider, M. Braun, and K. Schror
Factor Xa Releases Matrix Metalloproteinase-2 (MMP-2) From Human Vascular Smooth Muscle Cells and Stimulates the Conversion of Pro-MMP-2 to MMP-2: Role of MMP-2 in Factor Xa-Induced DNA Synthesis and Matrix Invasion
Circ. Res., May 31, 2002; 90(10): 1122 - 1127.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pepper, M. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pepper, M. S.
Related Collections
Right arrow Angiogenesis
Right arrow Growth factors/cytokines
Right arrow Fibrinogen/fibrin
Right arrow Other Vascular biology
Right arrow Other Research