Modulation of type-IV collagenase activity and invasive behavior of metastatic human melanoma (A2058) cells in vitro by monoclonal antibodies to type-IV collagenase

Melanoma Mediated Disruption of Brain Endothelial Barrier Integrity Is Not Prevented by the Inhibition of Matrix Metalloproteinases and Proteases

We have previously shown that human melanoma cells rapidly decrease human brain endothelial barrier strength. Our findings showed a fast mechanism of melanoma mediated barrier disruption, which was localised to the paracellular junctions of the brain endothelial cells. Melanoma cells are known to release molecules which cleave the surrounding matrix and allow traversal within and out of their metastatic niche. Enzymatic families, such as matrix metalloproteinases (MMPs) and proteases are heavily implicated in this process and their complex nature in vivo makes them an intriguing family to assess in melanoma metastasis. Herein, we assessed the expression of MMPs and other proteases in melanoma conditioned media. Our results showed evidence of a high expression of MMP-2, but not MMP-1, -3 or -9. Other proteases including Cathepsins D and B were also detected. Recombinant MMP-2 was added to the apical face of brain endothelial cells (hCMVECs), to measure the change in barrier integrity using biosensor technology. Surprisingly, this showed no decrease in barrier strength. The addition of potent MMP inhibitors (batimastat, marimastat, ONO4817) and other protease inhibitors (such as aprotinin, Pefabloc SC and bestatin) to the brain endothelial cells, in the presence of various melanoma lines, showed no reduction in the melanoma mediated barrier disruption. The inhibitors batimastat, Pefabloc SC, antipain and bestatin alone decreased the barrier strength. These results suggest that although some MMPs and proteases are released by melanoma cells, there is no direct evidence that they are substantially involved in the initial melanoma-mediated disruption of the brain endothelium.

Monoclonal antibodies against metzincin targets

The metzincin clan of metalloproteinases includes the MMP, disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs families, which cleave extracellular targets in a wide range of (patho)physiological processes. Antibodies constitute a powerful tool to modulate the activity of these enzymes for both therapeutic and research purposes. In this review, we give an overview of monoclonal antibodies (mAbs) that have been tested in preclinical disease models, human trials and important studies of metzincin structure and function. Initial attempts to develop therapeutic small molecule inhibitors against MMPs were hampered by structural similarities between metzincin active sites and, consequently, off-target effects. Therefore, more recently, mAbs have been developed that do not bind to the active site but bind to surface-exposed loops that are poorly conserved in closely related family members. Inhibition of protease activity by these mAbs occurs through a variety of mechanisms, including (i) barring access to the active site, (ii) disruption of exosite binding, and (iii) prevention of protease activation. These different modes of inhibition are discussed in the context of the antibodies' potency, selectivity and, importantly, the effects in models of disease and clinical trials. In addition, various innovative strategies that were used to generate anti-metzincin mAbs are discussed. LINKED ARTICLES: This article is part of a themed section on Translating the Matrix. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.1/issuetoc.

Wasting mechanisms in muscular dystrophy

Muscular dystrophy is a group of more than 30 different clinical genetic disorders that are characterized by progressive skeletal muscle wasting and degeneration. Primary deficiency of specific extracellular matrix, sarcoplasmic, cytoskeletal, or nuclear membrane protein results in several secondary changes such as sarcolemmal instability, calcium influx, fiber necrosis, oxidative stress, inflammatory response, breakdown of extracellular matrix, and eventually fibrosis which leads to loss of ambulance and cardiac and respiratory failure. A number of molecular processes have now been identified which hasten disease progression in human patients and animal models of muscular dystrophy. Accumulating evidence further suggests that aberrant activation of several signaling pathways aggravate pathological cascades in dystrophic muscle. Although replacement of defective gene with wild-type is paramount to cure, management of secondary pathological changes has enormous potential to improving the quality of life and extending lifespan of muscular dystrophy patients. In this article, we have reviewed major cellular and molecular mechanisms leading to muscle wasting in muscular dystrophy. This article is part of a Directed Issue entitled: Molecular basis of muscle wasting.

Recent findings on the role of gelatinases (matrix metalloproteinase-2 and -9) in osteoarthritis

Several studies dealing with the pathomechanisms of OA refer to MMP-1, -3, -7, -8, and -13 whereas a smaller number of investigations have pointed out the pathogenic role of gelatinases in OA. These gelatinases are best known for their involvement in pulmonary, myocardial, and neoplastic disease but they are emerging as important proteases implicated in the OA progression. This paper highlights the role of the gelatinases as emerging factors in OA pathogenesis through the regulation of subchondral bone resorption and microvascular invasion. The most significant new findings over the last year that add to our knowledge of the activity of these proteins in OA have been reported.

Osteopontin-stimulated expression of matrix metalloproteinase-9 causes cardiomyopathy in the mdx model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is a common and lethal form of muscular dystrophy. With progressive disease, most patients succumb to death from respiratory or heart failure, or both. However, the mechanisms, especially those governing cardiac inflammation and fibrosis in DMD, remain less understood. Matrix metalloproteinase (MMPs) are a group of extracellular matrix proteases involved in tissue remodeling in both physiologic and pathophysiologic conditions. Previous studies have shown that MMP-9 exacerbates myopathy in dystrophin-deficient mdx mice. However, the role and the mechanisms of action of MMP-9 in cardiac tissue and the biochemical mechanisms leading to increased levels of MMP-9 in mdx mice remain unknown. Our results demonstrate that the levels of MMP-9 are increased in the heart of mdx mice. Genetic ablation of MMP-9 attenuated cardiac injury, left ventricle dilation, and fibrosis in 1-y-old mdx mice. Echocardiography measurements showed improved heart function in Mmp9-deficient mdx mice. Deletion of the Mmp9 gene diminished the activation of ERK1/2 and Akt kinase in the heart of mdx mice. Ablation of MMP-9 also suppressed the expression of MMP-3 and MMP-12 in the heart of mdx mice. Finally, our experiments have revealed that osteopontin, an important immunomodulator, contributes to the increased amounts of MMP-9 in cardiac and skeletal muscle of mdx mice. This study provides a novel mechanism for development of cardiac dysfunction and suggests that MMP-9 and OPN are important therapeutic targets to mitigating cardiac abnormalities in patients with DMD.

Matrix metalloproteinase inhibitor batimastat alleviates pathology and improves skeletal muscle function in dystrophin-deficient mdx mice

Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, involves severe muscle degeneration, inflammation, fibrosis, and early death in afflicted boys. Matrix metalloproteinases (MMPs) are extracellular proteases that cause tissue degradation in several disease states. In this study, we tested the hypothesis that the expression levels of various MMPs are abnormally increased and that their inhibition will ameliorate muscle pathogenesis in animal models of DMD. Our results show that the transcript levels of several MMPs are significantly up-regulated, whereas tissue inhibitors of MMPs are down-regulated, in dystrophic muscle of mdx mice. Chronic administration of batimastat (BB-94), a broad spectrum peptide inhibitor of MMPs, reduced necrosis, infiltration of macrophages, centronucleated fibers, and the expression of embryonic myosin heavy chain in skeletal muscle of mdx mice. Batimastat also reduced the expression of several inflammatory molecules and augmented the levels of sarcolemmal protein beta-dystroglycan and neuronal nitric oxide in mdx mice. In addition, muscle force production in isometric contraction was increased in batimastat-treated mdx mice compared with those treated with vehicle alone. Furthermore, inhibition of MMPs using batimastat reduced the activation of mitogen-activated protein kinases and activator protein-1 in myofibers of mdx mice. Our study provides the novel evidence that the expression of MMPs is atypically increased in DMD, that their inhibition ameliorates pathogenesis, and that batimastat could prove to be a significant candidate for DMD therapy.

Matrix metalloproteinase-9 inhibition ameliorates pathogenesis and improves skeletal muscle regeneration in muscular dystrophy

Duchenne muscular dystrophy (DMD) is a fatal X-linked genetic disorder of skeletal muscle caused by mutation in dystrophin gene. Although the degradation of skeletal muscle extracellular matrix, inflammation and fibrosis are the common pathological features in DMD, the underlying mechanisms remain poorly understood. In this study, we have investigated the role and the mechanisms by which increased levels of matrix metalloproteinase-9 (MMP-9) protein causes myopathy in dystrophin-deficient mdx mice. The levels of MMP-9 but not tissue inhibitor of MMPs were drastically increased in skeletal muscle of mdx mice. Besides skeletal muscle, infiltrating macrophages were found to contribute significantly to the elevated levels of MMP-9 in dystrophic muscle. In vivo administration of a nuclear factor-kappa B inhibitory peptide, NBD, blocked the expression of MMP-9 in dystrophic muscle of mdx mice. Deletion of Mmp9 gene in mdx mice improved skeletal muscle structure and functions and reduced muscle injury, inflammation and fiber necrosis. Inhibition of MMP-9 increased the levels of cytoskeletal protein beta-dystroglycan and neural nitric oxide synthase and reduced the amounts of caveolin-3 and transforming growth factor-beta in myofibers of mdx mice. Genetic ablation of MMP-9 significantly augmented the skeletal muscle regeneration in mdx mice. Finally, pharmacological inhibition of MMP-9 activity also ameliorated skeletal muscle pathogenesis and enhanced myofiber regeneration in mdx mice. Collectively, our study suggests that the increased production of MMP-9 exacerbates dystrophinopathy and MMP-9 represents as one of the most promising therapeutic targets for the prevention of disease progression in DMD.

Melanoma associated spongiform scleropathy: characterization, biochemical and immunohistochemical studies

SUMMARY

Melanoma associated spongiform scleropathy (MASS) is a non-inflammatory scleral change with a spongiotic morphology seen in association with uveal melanoma. MASS is seen as whitish spindle shaped areas within the sclera that is adjacent to and in contact with a choroidal or ciliary body melanoma. This change can be seen as small scattered lesions in the inner scleral layers or as extensive areas along the whole extent of contact between the tumour and the sclera and involves most of the scleral thickness. MASS changes of different grades of severity were seen in 38% of 363 melanoma eyes investigated. The presence of MASS showed a statistical correlation with age. A significant high incidence of MASS was found in old age groups. This might due to the fact that MASS needs a longer period of contact between the tumour and the sclera to develop. It is also possible that age-related changes of the extracellular matrix might alter its response to melanoma produced factors leading to the development of MASS. The development of MASS and its severity are influenced by the extent of contact between the tumour and the sclera. This is supported by the significant statistical relation between the largest basal diameter of the tumours and the severity of MASS. Statistical correlation was found between MASS and scleral and extrascleral tumour extension. More than 90% of 82 specimens that showed tumour extension were associated with MASS. A biochemical analysis of scleral samples taken from areas with severe MASS showed a significant reduction of the main amino acids of collagen type I, which is the main scleral collagen. The amounts of total scleral proteins were significantly reduced. This scleral protein reduction is associated with an increase in glycosaminoglycans. These findings indicate a collagen degradation process. Immunohistochemical studies were performed to investigate the expression of matrix metalloproteinases (MMPs). In situ hybridization showed a significantly more frequent and more intense expression of MMP-2 by scleral fibroblasts in areas with MASS compared with areas without MASS. This was also seen by immunohistochemical staining. Similar high frequency and intense expression of MMP-2 were seen in tumour infiltrating macrophages. The results of biochemical and immunohistochemical studies indicate a collagen degradation process. This degradation may be the result of the proteolytic enzyme MMP-2 expressed by scleral fibroblasts under the effect of tumour humeral factors and/or tumour infiltrating macrophages. This scleral degradation results in fragmentation of the scleral collagen fibrils. This along with the accumulation of water in the sclera, as a result of the increase in the production of glycosaminoglycans, results in increase of scleral thickness in MASS areas and forms the histopathological picture of MASS. The scleral degradation may facilitate tumour invasion and may explain the statistical relation between MASS and scleral tumour invasion. MASS was found in a few of the eyes that had received pre-enucleation radiation. The possible explanation is that radiation might cause destruction of scleral fibroblasts reducing their ability to produce MMP-2, thus decreasing the development of MASS. No relation between MASS and survival was found. This is probably explained by the fact that the main cause of death due to uveal melanoma is distant metastasis. MASS changes are found to be associated with local tumour invasion but not statistically correlated to survival.

Production and characterization of a human single-chain Fv to collagenase IV

The over-expression of collagenase IV in tumor tissues was found to be closely related to tumor metastasis. Collagenase IV has been therefore considered as one of the novel indicative molecules for tumor diagnosis and treatment. Based on phage display antibody library technique, a single-chain Fv specific for colbgenase IV was successfully cloned. This antibody, referred to as hCo4, was mainly composed of variable regions from heavy and liiht chains, with its molecular weight of 27 ku. The engineered antibody bound to collagenase IV specifically. The affinity of hCo4 was found to be the same as that of a single-chain antibody constructed from a monoclonal antibody to collagenase IV. Since hCo4 is the smallest among all the antibodies specific for collagenase IV and it is of human origin, it has a potential to be applied for tumor irnmunotherapy and for the study of the relationship between collagenase IV and tumor metastasis.

Induction of secreted matrix metalloproteinase-9 activity in human melanoma cells by extracellular matrix proteins and cytokines

Degradation of matrix proteins that constitute the dermal-epidermal junction and dermis by proteolytic enzymes is an essential step of melanoma invasion and metastasis, and this is primarily achieved by the matrix metalloproteinases. In this report, using zymography, we compared the basal secretion levels of active matrix metalloproteinase-2 and matrix metalloproteinase-9 to levels in response to various extracellular matrix proteins, cytokines, and growth factors in normal human melanocyte cells and melanoma cell lines from different stages of neoplastic progression. Basal matrix metalloproteinase-9 activity was only detected in vertical growth phase and metastatic melanoma cell lines, suggesting that matrix metalloproteinase-9 is a candidate biomarker for identifying vertical growth phase and metastatic melanomas. Most melanoma cell lines and cultured normal melanocytes produced high levels of matrix metalloproteinase-2. In addition, both tumor necrosis factor-alpha and interleukin-1beta are strong inducers of active matrix metalloproteinase-9 in vertical growth phase melanoma cell lines, indicating a possible role of these cytokines in the switch from radial growth phase to vertical growth phase. We propose that these proinflammatory cytokines promote melanoma invasion in part through upregulating matrix metalloproteinase-9. Both these cytokines are released from keratinocytes in the epidermis by ultraviolet radiation. Thus, our study suggests that the microenvironment of melanoma cells is an important feature in melanoma progression, and ultraviolet-radiation-induced cytokines might promote the progression of melanoma through the release or activation of matrix metalloproteinases.

Collagenase-3 (MMP-13) expression in cutaneous malignant melanoma

BACKGROUND

Matrix metalloproteases (MMPs), enzymes with the ability to degrade the extracellular matrix, play an important role in tissue invasion by cutaneous malignant melanoma (CMM). One specific MMP, collagenase-3 (MMP-13), is thought to have a key function in the activation of MMP.

AIMS

To evaluate the expression of MMP-13 in CMM and assess its possible relationship to clinical and pathological parameters.

METHODS

MMP-13 expression was analyzed in 51 paraffin-embedded tumor samples from patients with invasive CMM, ten samples from in situ melanomas, and in eight samples from benign lesions (three dermal melanocytic nevi, three compound melanocytic nevi and two atypical melanocytic nevi) using immunohistochemical techniques. The median follow-up period in patients with invasive CMM was 50 months.

RESULTS

Benign lesions were consistently negative for MMP-13, whereas three of the ten in situ melanomas (30%) and 23 of the 51 invasive CMMs (45%) showed positive immunostaining for MMP-13. The percentage of MMP-13-positive tumors correlated significantly and positively with the mitotic index (p=0.002) in invasive CMM. However, our results did not show any significant association between tumoral MMP-13 expression and relapse-free survival in patients with invasive CMM.

CONCLUSIONS

MMP-13 appears to be a factor associated with tumor aggressiveness in CMM. It seems to eliminate an important barrier not only against tumoral invasion but also against proliferation.

The role of chemokines and extracellular matrix components in the migration of T lymphocytes into three-dimensional substrata

The role of chemokines and their interactions with extracellular matrix components (ECM) or the capacity of T cells to migrate into and accumulate within three-dimensional (3D) collagen type 1 substrata was studied. We examined the influence of chemokines and fibronectin on the infiltration properties of non-infiltrative (do not migrate into 3D substrata) and spontaneously infiltrative (migrate into 3D substrata) T-cell lines. Infiltrative and non-infiltrative T-acute lymphocytic leukaemic cell lines exhibited no consistent differences with respect to the expression of various chemokine receptors or beta(1)-integrins. Chemokines presented inside the collagen increased the depth of migration of infiltrative T-cell lines, but did not render non-infiltrative T-cell lines infiltrative, although they augmented the attachment of non-infiltrative T-cell lines to the upper surface of the collagen. The presence of fibronectin inside the collagen did not render non-infiltrative T-cell lines infiltrative, but markedly augmented the migration of 'infiltrative' T-cell lines into collagen. Both infiltrative and non-infiltrative T-cell lines showed migratory responses to chemokines in Boyden assays (migration detected on 2D substrata). These results indicate that the process of T-cell infiltration/migration into 3D substrata depends on a tissue penetration mechanism distinguishable from migration on 2D substrata and that the basic capacity of T cells to infiltrate is independent of chemokines and ECM components applied as attractants.

Identification of activated matrix metalloproteinase-2 (MMP-2) as the main gelatinolytic enzyme in malignant melanoma by in situ zymography

The involvement of extracellular matrix-degrading enzymes, such as matrix metalloproteinases and serine proteases, during tumour progression and metastasis is well established. In particular, the activation of pro-matrix metalloproteinase (MMP)-2 on the surface of malignant cells by membrane-bound MT1-MMP has been shown to contribute to the invasive abilities of various tumours. This study presents evidence that in tissue of malignant melanomas, increased effective gelatinolytic activity is mainly located at sites where melanoma cells interact with the surrounding extracellular matrix. Forty-one primary melanomas (30 superficial spreading and 11 nodular type) and six lymph node metastases were investigated by a modified technique of gelatin in situ zymography. This technique localizes areas of effective proteolytic activity within tissue sections. In 28/41 (68%) primary melanomas and in 6/6 (100%) metastases, considerable proteolysis was detected at the invading part of the tumour and especially at sites of tumour-stroma interactions, whereas no or only weak proteolytic activity was localized within the centres of solid nests of tumour cells. Zymographic analysis of extracts obtained from different areas of microdissected melanoma specimens identified activated MMP-2 as the enzyme responsible for this activity. Immunohistochemical analysis detected strong staining for MMP-2 and MT1-MMP, even in areas in which no proteolytic activity was found by in situ zymography, emphasizing the importance of more functional techniques for the investigation of balanced proteolytic systems. This technology makes it possible to draw conclusions regarding the balance between activated proteases and inhibitors, which are frequently found to be present together in close proximity in vivo.

The levels of trypsinogen isoenzymes in ovarian tumour cyst fluids are associated with promatrix metalloproteinase-9 but not promatrix metalloproteinase-2 activation

Proteolysis mediated by matrix metalloproteinases (MMPs) and serine proteinases is associated with cancer invasion and metastasis. Activation of latent proMMPs, and especially the proforms of the type IV collagen degrading gelatinases A and B (proMMP-2 and proMMP-9), is thought to be a critical step in this process. We have recently found that human tumour-associated trypsin-2 is a potent activator of proMMP-9 and it also activates proMMP-2 in vitro. Trypsinogen, MMP-2, and MMP-9 are expressed in ovarian cancer. To elucidate the function of trypsin in vivo, we studied whether high concentrations of trypsinogen-1, trypsinogen-2, their alpha(1)-proteinase inhibitor (API) complexes, and tumour-associated trypsin inhibitor (TATI) are associated with proMMP-2 and proMMP-9 activation in ovarian tumour cyst fluids. Zymography and immunofluorometric analysis of 61 cyst fluids showed a significant association between high trypsin concentrations and the activation of MMP-9 (P = 0.003-0.05). In contrast, the trypsin concentrations were inversely associated with the activation of MMP-2 (P = 0.01-0.02). Immunohistochemical analysis of ovarian tumour tissue demonstrated expression of trypsinogen-2 and TATI in the secretory epithelium. MMP-2 was detected both in stromal and epithelial cells whereas MMP-9 was detected in neutrophils and macrophage-like cells in stromal and epithelial areas. These results suggest that trypsin may play a role in the regulation of the MMP-dependent proteolysis associated with invasion and metastasis of ovarian cancer.

Expression of integrins, degradative enzymes and their inhibitors in uveal melanoma: differences between in vitro and in vivo expression

Posterior uveal melanoma is the most common intraocular malignancy in adults. Metastasis occurs in approximately 40% of all cases and spread is primarily to the liver. Once secondary hepatic disease has developed the prognosis is poor. Metastasis involves a series of adhesion and de-adhesion events, coupled with regulated tissue degradation to facilitate tumour cell invasion and spread to both local and distant sites. These processes are assisted by the expression of integrins and degradative enzymes by both tumour and host cells. Using a series of 10 uveal melanomas, we investigated the expression of a panel of integrins, degradative enzymes and their inhibitors that have been shown to be associated with metastasis. In addition, we undertook to establish if there might be differential expression in response to growth under artificial conditions. All the tumours expressed matrix metalloproteinases (MMP)-2 and-9, tissue inhibitor of metalloproteases (TIMP)-2, urokinase plasminogen activator (u-PA), plasminogen activator inhibitor (PAI)-1 and PAI-2. Differences in the expression of the integrins alpha1beta1, alpha2beta1 and alpha6beta1 were observed; in particular, these differences appeared to relate to expression as a consequence of growth in culture. In summary, uveal melanoma cells express both degradative enzymes and their respective inhibitors, which are important in metastasis. It would appear that differential expression of integrins is present, probably as a response to in vitro stimulation.

High collagenase-1 expression correlates with a favourable chemoimmunotherapy response in human metastatic melanoma

Matrix metalloproteinases (MMPs) are proteolytic enzymes that can degrade extracellular matrix and thus enhance metastasis. We have studied the expression of two collagenolytic MMPs in 37 samples obtained from 26 patients treated for metastatic melanoma. Interestingly, the samples showed a different expression pattern of collagenase-1 (MMP-1) and collagenase-3 (MMP-13). The samples with high expression levels of MMP-1 (n = 18) were more frequently MMP-13 negative (14 out of 18), whereas those with low expression levels of MMP-1 (n = 15) were predominantly positive for MMP-13 (nine out of 15) (P = 0.027). High expression levels of MMP-1 were associated with a favourable response to chemoimmunotherapy. Responders (n = 13) frequently had intensively MMP-1-expressing metastases (nine out of 13), especially those who achieved a complete response (five out of six). Response failures (n = 7) mainly had metastases with a low intensity of MMP-1 expression (six out of seven) (P = 0.019). There was a tendency towards longer survival among patients with intensively MMP-1-expressing tumours (median 14.3 versus 6.7 months, P = 0.068). The high expression levels of MMP-1 correlated with low MIB-1 (to nuclear antigen Ki-67) (P = 0.019) and positivity for MMP-13 was associated with high MIB-1 expression (P = 0.00048), suggesting that their different expression patterns may affect tumour growth and contribute to differences in patient survival.

The role of matrix metalloproteinases in tumor angiogenesis and tumor metastasis

Although a considerable amount of effort has been placed on discovering the etiologies of cancer, the majority of the basic cancer research existing today has focused on understanding the molecular mechanism of tumor formation and metastasis. Metastatic spread of tumors continues to be a major obstacle to successful treatment of malignant tumors. Approximately 30% of those patients diagnosed with a solid tumor have a clinically detectable metastasis and for the remaining 70%, metastases are continually being formed throughout the life of the tumor. Even after the tumor is excised, the threat of death is attributable to the metastasis that may occur through the remaining tumor cells. In addition, treating the metastasis often proves futile since metastasis often vary in size, composition, and anatomical location. New treatments blocking the formation of metastasis will provide greater chances of survival for cancer patients. One family of enzymes that has been shown over the years to play a role in tumor progression is the matrix metalloproteinase (MMP) family. The main function of MMPs, also known as matrixins, is degradation of the extracellular matrix physiologic function involving MMPs include wound healing, bone resorption and mammary involution. MMPs, however, also contribute to pathological conditions including rheumatoid arthritis, coronary artery disease, and cancer. Tumor cells are believed to utilize the matrix degrading capability of these enzymes to spread to distant sites. In addition, MMPs also are thought to promote the growth of these tumor cells once they have metastasized. This review will discuss the role of MMPs and their inhibitors in tumor invasion, angiogenesis and metastasis with special emphasis on the gelatinases, MMP-2 and MMP-9.

Overexpression of vacuolar ATPase 16-kDa subunit in 10T1/2 fibroblasts enhances invasion with concomitant induction of matrix metalloproteinase-2

Recent studies show that the vacuolar-type H(+)-ATPase (V-ATPase) 16 kDa subunit is expressed on plasma membrane of cancer cells. We hypothesized that V-ATPase 16 kDa subunit is directly involved in cell invasion. In the present study we established transfectants overexpressing V-ATPase 16 kDa subunit at the mRNA level, and found that these transfectants showed an enhanced invasiveness through matrigel with a concomitant increases in secretion of matrix metalloproteinase-2. Moreover, antisense oligonucleotides of the V-ATPase 16 kDa subunit suppressed invasive human A549 cell invasion with concomitant decreases in secretion of matrix metalloproteinase-2. The results suggest that the V-ATPase 16 kDa subunit is directly involved in cell invasion and that matrix metalloproteinase-2 is responsible for promoting the invasion by the V-ATPase 16 kDa subunit.

Infiltrative capacity of T leukemia cell lines: a distinct functional property coupled to expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1)

Infiltrative capacity was found to distinguish separate T leukemia cell lines. Of seven T-cell lines four exhibited capacity to infiltrate Matrigel. Analysis of infiltration was performed at the single-cell level throughout the Matrigel using a depth meter. Further, we examined differences in migration capacity and metalloproteinase production between infiltrating and non-infiltrating T-cell lines. The capacity to infiltrate was not directly correlated to the capacity to adhere to the Matrigel or to migrate on/to extracellular matrix components. It is concluded that infiltration capacity does not simply reflect capacity to migrate but represents a distinct functional property. The production of metalloproteinases and their inhibitors by the separate T-cell lines was analyzed using rt PCR, biosynthetic labelling, zymography, immunoprecipitation and ELISA. All T-cell lines with capacity to infiltrate produced matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) while non-infiltrating cell lines did not express MMP-9. Expression of MMP-1, 2, 3, 10, 14 and 17 showed no correlation to capacity to infiltrate. Analysis of infiltration in the presence of a metalloprotease inhibitor showed an increased number of cells within the gel. This enhancement of infiltration suggests that the function of MMPs and/or their inhibitors in lymphocyte infiltration is more complex than previously thought.

Expression and activation of pro-gelatinase A by human melanoma cell lines with different tumorigenic potential

The production of various proteolytic enzymes by tumor cells facilitate the invasion of solid tumors into surrounding tissues. We examined three cell lines (M1Dor, M4Be and M3Da) derived from malignant melanoma which exhibited different abilities to grow in nude mice following subcutaneous grafting. By in vitro invasion assay using Boyden-chambers technique, we found that none of those cell lines were able to invade the Matrigel. Several studies have substantiated the role of matrix metalloproteinases (MMP), mainly gelatinases MMP-9 and MMP-2, in melanoma cell invasion. Each cell line constitutively produced MMP-2 (but not MMP-9) in its latent form only, with stronger production for the most tumorigenic cell line in vivo (M3Da). Integrity of the MMP-2 activation process was studied since MMP-2 was also recovered as zymogen at the cell plasma membrane. All cell lines secreted TIMP-1 and TIMP-2 in a constitutive manner and again, but TIMP-2 production as well as MT1-MMP expression were found inversely related to their tumorigenic potential. Plating cells onto type I or type IV collagen did not trigger pro-MMP-2 activation; on the contrary, conversion of pro-MMP-2 to its active form could be evidenced when melanoma cell lines were seeded in a three dimensional type I collagen lattice.

Gelatinase A-immunoreactive protein in ovarian lesions- prognostic value in epithelial ovarian cancer

OBJECTIVE

Gelatinase A (MMP-2) is a member of the matrix metalloproteinase family and it degrades the major component of the basement membrane, type IV collagen. MMP-2 has been linked to invasion in different types of cancer.

METHOD

We have studied the localization of MMP-2 in 18 benign, 3 borderline, and 33 malignant ovarian lesions by immunohistochemical stainings using a monoclonal antibody against MMP-2.

RESULTS

MMP-2-immunoreactive protein was localized in epithelial cells and in fibroblasts. Two types of cytoplasmic staining were observed, a diffuse and a granular pattern. The diffuse staining model was found more often. In 19% of the cases, both staining patterns were present in epithelial cells. Granular staining was found in epithelial cells in cystadenomas and in ovarian cancer cells. The pattern of MMP-2 positivity in fibroblasts was diffuse. MMP-2 positivity in cancer cells was associated with recurrent disease (P < 0.05) in ovarian cancers. MMP-2 negativity in fibroblasts correlated to Grade 3 (P < 0.01), Stage III-IV (P < 0.001), recurrency (P < 0.05), and refractory disease (P < 0.05) in ovarian cancer. The relative survival rate was 32% in patients with an MMP-2-positive ovarian cancer, 57% in patients with an MMP-2-negative ovarian cancer, and 19% in patients with MMP-2 positivity in cancer cells and concomitant negativity in stromal fibroblasts. The disease-free 5-year survival rates were 25, 57, and 12.5%, respectively.

CONCLUSIONS

These data suggest that MMP-2 may contribute to poor prognosis of ovarian cancer.

Matrix metalloproteinase-2 (MMP-2) immunoreactive protein--a new prognostic marker in uveal melanoma?

Uveal melanoma is the most common primary intraocular tumour. Once haematogenous metastasis has occurred, there is no cure for the disease and there is an obvious need for new biological prognostic markers to estimate the risk of metastasis. In this study, the expression of matrix metalloproteinase-2 (MMP-2) was characterized immunohistochemically in 29 human uveal melanomas. Enzyme-linked immunoassays and gelatin zymographies were assessed in order to quantify the expression of gelatinases A and B, as well as the tissue inhibitor of metalloproteinases (TIMPs), in the vitreous body. A total of 49 per cent of the uveal melanomas displayed a positive immunoreaction for MMP-2 in melanoma cells, the epithelioid cells showing the most frequent staining. There was no correlation between the positivity of MMP-2 staining and the size of the primary tumour, gender or age. The expression of MMP-2 was associated with a dismal prognosis: the 5-year overall survival rate for MMP-2-positive cases was significantly inferior to that of the MMP-2 negative cases, 49 per cent vs. 86 per cent, respectively (p=0.02). A patient group at high risk of metastatic disease was identified; only 38 per cent of patients with a MMP-2-positive non-spindle cell uveal melanoma survived for 5 years. The analyses of MMPs or TIMPs in the vitreous body had no prognostic value. Positive immunostaining for MMP-2 was observed in the retinal pigment epithelium, corneal epithelium, and fibroblasts in the ciliary body and choroid. It is concluded that immunohistochemical analysis of MMP-2 may help to predict a risk of metastasis in uveal melanoma.

Expression of collagenases-1 and -3 and their inhibitors TIMP-1 and -3 correlates with the level of invasion in malignant melanomas

Since proteolysis of the dermal collagenous matrix and basement membranes is required for local invasive growth and early metastasis formation of cutaneous melanomas, we have analysed the activities/expression levels of certain metalloproteinases in melanomas and cultured melanoma cells by in situ hybridization and Northern analysis. In addition to collagenases-1 and -3 that have been implicated in invasive growth behaviour of various malignant tumours, we analysed the levels of 72-kDa gelatinase and its activators MT1-MMP and TIMP-2 in cultured melanoma cells. The lesions examined included three cases of lentigo maligna and 28 cases of Clark grade I-V melanomas. The premalignant as well as the grade I tumours were consistently negative for collagenase-1 and -3 and TIMP-1 and -3. The collagenases were predominantly expressed in the cancer cells of Clark grade III and IV tumours. TIMP-1 and -3 were abundantly expressed in the cancer and/or stromal cells of grade III and IV melanomas, while TIMP-2 protein was detected also in melanomas representing lower invasive potential. Northern analysis of seven melanoma cell lines showed that the expression of collagenase-1 and TIMPs-1 and -3 was associated with 72-kDa gelatinase positivity. All melanoma cell lines were positive for MT1-MMP and TIMP-2 mRNAs. Our results suggest that overexpression of collagenases-1 and -3 and TIMPs-1 and -3 is induced during melanoma progression. Expression of TIMPs may reflect host response to tumour invasion in an effort to control MMP activity and preserve extracellular matrix integrity.

Matrix metalloproteinase 2 immunoreactive protein appears early in cervical epithelial dedifferentiation

OBJECTIVE

Expression of the immunoreactive protein of matrix metalloproteinase 2 (MMP-2) was studied in cervical tumors representing various stages of cell atypia and differentiation. In this study, we evaluated whether the expression of MMP-2 is an early or late event in the process of dedifferentiation and cancer progression.

METHODS

Paraffin tissue sections from 60 cervical neoplasias including 38 cervical intraepithelial neoplasias (CINs) and 22 early-stage (stage IB and IIA) squamous cervical carcinomas were studied with respect to the expression of MMP-2 protein by using immunoperoxidase staining.

RESULTS

The staining pattern of MMP-2 in the CIN lesions usually differed from that in squamous carcinoma. Latent MMP-2 protein localized, in most of the cases, to the periphery of the CIN cells, but was diffuse in the cytoplasm of the carcinoma cells. No correlation was found between overexpression of MMP-2 protein and degree of dysplasia, nor was there any association between MMP-2 and human papillomavirus (HPV). High scores for MMP-2 were observed only in histologically higher-grade early-stage cervical carcinomas. The lymph node metastases derived from high-MMP-2-score primary tumors were also positive for MMP-2. No correlation between MMP-2 staining and clinical course or prognosis was found.

CONCLUSIONS

MMP-2 expression is an early event during dedifferentiation and malignant transformation in cervical neoplasias. The pattern of staining is different in CIN than in squamous carcinoma cells, in which overexpression may correlate with the degree of anaplasia.

Prognostic value of MMP-2 immunoreactive protein (72 kD type IV collagenase) in primary skin melanoma

The penetration of the subepithelial basement membrane is the first critical step in the dissemination of melanoma. In vitro studies have suggested that the 72 kD type IV collagenase (MMP-2) may be important in melanoma invasion. It has recently been demonstrated that the expression of MMP-2 immunoreactive protein increased with increasing atypia in melanocytic tumours and was associated with later haematogenous metastases in melanoma. This paper investigates the value of MMP-2 as a possible prognostic marker in melanoma. The expression of MMP-2 immunoreactive protein was studied with immunoperoxidase staining in paraffin-embedded sections of 50 cases of primary skin melanoma by using specific, affinity purified antibodies. Positive immunostaining was quantified by counting the percentage of positive cancer cells and was compared with clinical patient characteristics and survival. Sixty-four per cent of the primary melanoma cases displayed positive cytoplasmic immunostaining for MMP-2 in tumour cells. Marked overexpression of MMP-2 protein (> or = 34 per cent of melanoma cells positive) correlated with the 5-year survival of the patients when compared with patients with lower MMP-2 positivity, 55 per cent vs. 85 per cent, respectively (P < 0.05). Male patients displayed positive staining more often than females (75 per cent vs. 54 per cent, respectively). There was no correlation between MMP-2 positivity and Clark level or Breslow classification. A distinct group with unfavourable prognosis was identified. The 10-year survival for MMP-2-positive male melanoma patients was 39 per cent as opposed to 79 per cent with the other melanoma patients (P < 0.05). In the hierarchic Cox regression model for survival, MMP-2 immunoreactive protein was found to be independent of Clark level and Breslow classification. Overexpression of MMP-2 protein indicated a 4.5-fold relative risk of dying from melanoma. It is concluded that MMP-2 immunoreactive protein in melanoma cells is an independent prognostic factor for survival. High MMP-2 expression in male melanoma patients indicates an unfavourable prognosis.

Assay of matrix metalloproteinases types 1, 2, 3 and 9 in breast cancer

Matrix metalloproteinases (MMPs) are zinc dependent endopeptidases implicated in cancer invasion and metastasis. Gelatin zymography was performed on 84 human breast carcinomas and seven normal breast tissues. The precursor form of MMP-2 (72 kDa) was found in 11 (12%) samples, while its two activated forms, i.e. 62 kDa and 59 kDa, were found in three (6%) and 34 (40%) samples respectively. In contrast to MMP-2, most of the samples (52%) contained MMP-9 in its precursor form. Using ELISA, MMP-1 levels were found in 12% of the samples while MMP-3 levels were found in only 2% of the samples. Levels of MMP-2, -3 and -9 correlated inversely with numbers of nodal metastases. Neither MMP-2 nor -9 levels were significantly related to patient outcome. However, patients with high levels of a 50-kDa gelatinase band after zymography had a significantly better survival than patients with low levels. This species was never observed in normal breast tissue.

Ovarian cancer cell invasion is inhibited by paclitaxel

Overproduction of matrix metalloproteinases (MMPs) and alterations in adhesive and migratory behavior are common characteristics of metastatic cancer cells. Ovarian cancer is a highly invasive type of malignancy. The effect of the antineoplastic drug paclitaxel on human ovarian cancer cell (Ovcar-3) invasion was studied using an in vitro invasion assay with reconstituted basement membrane. The effect of treatment with paclitaxel was also determined separately on certain invasion-associated events, such as the secretion of 72 kDa type IV collagenase (gelatinase A/MMP-2), the expression of the tissue inhibitor of metalloproteinase-2 (TIMP-2), cell attachment and migration. Ovcar-3 cell attachment, migration and in vitro invasion were significantly decreased after paclitaxel treatment (P = 0.02, P < 0.01 and P = 0.001, respectively) whereas no alteration in the secretion of latent MMP-2 was noted. However, the intracellular localization of the immunoreactive protein for MMP-2 was altered in response to paclitaxel treatment. Interestingly, paclitaxel increased the appearance of TIMP-2 protein in culture medium (P = 0.002) but did not change the expression of mRNA for TIMP-2 in Ovcar-3 cells. These data show that paclitaxel is an effective suppressor of Ovcar-3 cell invasion. It inhibits attachment and migratory activities of the cells but also causes a release of TIMP-2 protein into the tissue culture medium.

Matrix metalloproteinases

BACKGROUND

The matrix metalloproteinases (MMPs) have a role in gastrointestinal malignancy. This role is reviewed, with particular reference to the gelatinase subgroup of enzymes.

METHODS

All relevant papers derived from the Medline and Enbase databases between 1984 and early 1996 were reviewed.

RESULT AND CONCLUSION

There is now strong evidence that MMPs play a major role in tumour invasion and metastasis. The development of MMP inhibitors may lead to important new treatment for the control of malignant disease.

Misregulation of stromelysin-1 expression in mouse mammary tumor cells accompanies acquisition of stromelysin-1-dependent invasive properties

Stromelysin-1 is a member of the metalloproteinase family of extracellular matrix-degrading enzymes that regulates tissue remodeling. We previously established a transgenic mouse model in which rat stromelysin-1 targeted to the mammary gland augmented expression of endogenous stromelysin-1, disrupted functional differentiation, and induced mammary tumors. A cell line generated from an adenocarcinoma in one of these animals and a previously described mammary tumor cell line generated in culture readily invaded both a reconstituted basement membrane and type I collagen gels, whereas a nonmalignant, functionally normal epithelial cell line did not. Invasion of Matrigel by tumor cells was largely abolished by metalloproteinase inhibitors, but not by inhibitors of other proteinase families. Inhibition experiments with antisense oligodeoxynucleotides revealed that Matrigel invasion of both cell lines was critically dependent on stromelysin-1 expression. Invasion of collagen, on the other hand, was reduced by only 40-50%. Stromelysin-1 was expressed in both malignant and nonmalignant cells grown on plastic substrata. Its expression was completely inhibited in nonmalignant cells, but up-regulated in tumor cells, in response to Matrigel. Thus misregulation of stromelysin-1 expression appears to be an important aspect of mammary tumor cell progression to an invasive phenotype.

Anti-alpha3 integrin antibody induces the activated form of matrix metalloprotease-2 (MMP-2) with concomitant stimulation of invasion through matrigel by human rhabdomyosarcoma cells

Proteolytic enzymes, such as matrix metalloproteases (MMPs), play a pivotal role in cancer invasion and metastasis. Invasive human rhabdomyosarcoma cells (RD) secreted proMMP-2 (72-kDa progelatinase). We found that anti-alpha3 and -alpha2 integrin antibodies induced the activated form of MMP-2 and enhanced proMMP-2 secretion by RD cells. The effect of anti-alpha2 integrin antibody was less prominent than that seen with anti-alpha3 integrin antibody. Moreover, we have found that anti-alpha3 and -alpha2 integrin antibodies enhanced RD-cell invasion through matrigel (reconstituted basement membrane) by 2.6- and 2.0-fold respectively this process was abrogated by neutralizing antibody to MMP-2. These data suggest that signaling events induced by anti-alpha3 integrin antibody may be involved in RD-cell invasion as a result of modulation of matrix-metalloprotease expression.

Matrix metalloproteinase-2 (72 kD type IV collagenase) expression occurs in the early stage of human melanocytic tumour progression and may have prognostic value

Matrix metalloproteinase-2 (MMP-2), a member of the matrix metalloproteinase family, participates in degradation of the pericellular and extracellular matrix during neoplastic growth and metastasis. Experimental data have substantiated its role in melanoma invasion, but there is no information at present concerning its expression in histological specimens from human melanocytic tumors. This study describes the occurrence and immunolocalization of MMP-2 in human melanocytic lesions, defining distinct steps in melanoma progression. Paraffin-embedded sections from 118 melanocytic lesions were immunostained using a specific antibody to 72 kD type IV collagenase. The material included 34 common naevocellular naevi, 14 dysplastic naevi, 21 in situ melanomas, 20 primary malignant melanomas, and 29 melanoma metastases. Intracytoplasmic MMP-2 immunoreactive protein was found in the 'naevocytic nests' of common naevi, in junctional naevus cells, and in melanoma cells. The surrounding normal skin stained negatively, except for occasional macrophages, sweat glands, and hair follicles. The number of MMP-2-positive cells increased with decreasing architectural organization and increasing atypia in the melanocytic lesions. The MMP-2 positivity in the primary and subcutaneous melanoma lesions correlated with later haematogenous metastasis. The data suggest that MMP-2 expression is an early event in melanocytic tumour progression, but is nevertheless prognostic for haematogenous metastasis in melanoma.

Comparison of migration and invasiveness of epithelial tumor and melanoma cells in vitro

Tumor invasion of basement membranes is a complex multi-step process. Altered adhesion, as well as increased cell locomotion contribute to tumor cell invasion and metastasis. A variety of in vitro models have been used to measure cell invasiveness. The invasion of basement membranes can be simulated in vitro in blind well Boyden Chambers using the reconstituted basement membrane matrigel or collagen type I as the invasion barrier. The aim of our study was to compare the migration and invasive capacity of epidermal tumor cells (TR 131, TR 146, SCL II, FaDu, HLaC 79) and melanoma cells derived from primary tumors (Mel Ei, Mel Ho, Mel Juso, Mel Wei) or their metastases (Mel Ju, Mel Im, Sk Mel 1, Sk Mel 28). Chemotactic response of epidermal tumor cells was increased toward fibroblast conditioned medium and fibronectin (20 micrograms/ml), while laminin (100 micrograms/ml) stimulated chemotaxis in only 3 epidermal tumor cell lines (HLaC 79, FaDu, TR 146), EGF (10 ng/ml) in only 4 cases (SCL II, FaDu, TR 131, TR 146), and interleukin-1 (IL-1) in only 1 case (FaDu). Epithelial tumor cell conditioned medium had no chemotactic influence on epithelial tumor cells. Fibroblast conditioned medium, fibronectin, EGF and PDGF were potent chemoattractants for all melanoma tumor cells, whereas IL-1 did not induce a significant chemotactic response. While two epithelial tumor cell lines (FaDu, TR 146) were able to penetrate collagen type I, matrigel was an impenetrable barrier for all epithelial tumor cells. Two cell lines from melanoma primary tumors (Mel Ho, Mel Ei) and two cell lines from melanoma metastases (Sk Mel 1, Sk Mel 28) showed no invasion through collagen type I and matrigel, whereas invasion through both barriers could be observed for the metastatic cell lines Mel Ju and Mel Im and in the primary tumor cell line Mel Wei. Therefore, the clinical observation of late and rare metastasis in epithelial tumors and early metastasis in melanoma correlate with our in vitro investigation of invasive behavior in tumor cells. No significant correlation between the invasiveness of melanoma cell lines and their clinical origin could be demonstrated suggesting the existence of subpopulations with varying invasive potential.

Monoclonal antibodies against human collagenase and stromelysin

Mouse monoclonal antibodies against recombinant human fibroblast procollagenase and prostromelysin have been generated and characterized. The epitope-containing domains for the antibodies have been assigned based on their immunoreactivities against recombinant proenzymes, mature enzymes, truncated collagenases, proteolytic fragments of stromelysin, and chimeric molecules constructed from different domains of the two enzymes. These antibodies can be divided into four groups: (1) antibodies that recognize the truncated 19-kDa NH2-terminal collagenase, (2) antibodies that recognize the C-terminal domain of collagenase and stromelysin, (3) antibodies that recognize a 31-kDa NH2-terminal collagenase fragment, and (4) antibodies that recognize the 19-kDa NH2-fragment of stromelysin. The prostromelysin-specific antibody 11N13 is of particular interest; it neutralizes stromelysin activity in a stromelysin peptide substrate assay, with an IC50 value of 75 nM. MAb 11N13 may be useful for in vivo and in vitro studies to validate the roles of stromelysin in tumor cell invasion, metastasis, and connective tissue disorders.

Assay of matrix metalloproteases types 8 and 9 by ELISA in human breast cancer

Results from model tumour systems suggest that either increased levels of certain metalloproteases (MMPs) or decreased levels of their inhibitors correlate with metastatic potential. In this study, levels of two MMPs, i.e. MMP-8 and -9, and their inhibitor tissue inhibitor of metalloprotease type 1 (TIMP-1) were measured by enzyme-linked immunosorbent assay in human breast tumours. Levels of MMP-8 and -9 correlated significantly with each other, but neither MMP correlated with urokinase plasminogen activator. Levels of both MMP-8 and -9 were also significantly related to levels of TIMP-1. In contrast, neither MMP correlated with plasminogen activator inhibitor. No relationship was found between MMP-8, MMP-9 or TIMP-1 and either tumour size or metastasis to axillary nodes. MMP-8 and -9 levels were inversely related to levels of oestrogen receptors. MMP-8 but not MMP-9 levels were also inversely correlated with progesterone receptor levels. It is concluded that the assay for MMP-8 and -9 described here will permit the evaluation of these proteases as prognostic markers in cancer.

Molecular and cellular basis of cancer invasion and metastasis: implications for treatment

In the past decade significant advances in establishing the underlying biological mechanisms of tumour invasion and metastasis have been made. Some of the triggering factors and genes relevant to metastatic spread have been identified. Advances have also been made in understanding the signal transduction pathways involved in invasion and metastasis. This increased comprehension of the malignant metastatic process has enabled new antimetastatic strategies to be devised. This review summarizes progress in these areas and discusses the implications for the treatment of metastasis.

TIMP-2 expression modulates human melanoma cell adhesion and motility

Invasion of cells across extracellular matrix barriers requires attachment of cells to the matrix, creation of a proteolytic defect in the matrix, and migration of the cells through the defect. To date, alterations in the balance between matrix metalloproteinases (MMPs) and their inhibitors have been shown to alter cellular invasion only through effects on matrix degradation. We used a retroviral infection system to over- and underproduce tissue inhibitor of metalloproteinase-2 (TIMP-2) in human A2058 melanoma cells. Our results indicate that altering the balance of MMPs and TIMP-2 through genetic manipulation of TIMP-2 production modulates not only proteolysis of the extracellular matrix but also cell attachment to the extracellular matrix and motility of cells through matrix components. Altering the production of TIMP-2 also results in the ability of cells to form foci. These results implicate the MMPs and their inhibitors in all aspects of the cellular invasion cascade. This supports the hypothesis that highly invasive cell lines establish a balance of MMPs and inhibitors that is optimal for invasion, and alteration of this balance in either direction results in perturbation of the invasive phenotype.

Modulation of M(r) 72,000 and M(r) 92,000 type-IV collagenase (gelatinase A and B) gene expression by interferons alpha and gamma in human melanoma

The purpose of this study was to determine how interferons alpha and gamma influence the expression of M(r) 72,000 type-IV collagenase (gelatinase A) and M(r) 92,000 type-VI collagenase (gelatinase B) genes and whether there are differences in their gene expression. Special emphasis was focused on the treatment time. Total cellular RNA from A2058 human melanoma cells treated for various time periods with IFN-alpha or gamma was analyzed by Northern- and slot-blot hybridization. Both M(r) 72,000 and M(r) 92,000 type-IV collagenase mRNAs were detectable in A2058 cells and mRNA levels for both gelatinases were significantly up-regulated in the cells treated for a short time period with either IFN-alpha or gamma. In contrast, a long-term treatment (7 days) with these drugs markedly down-regulated the genes for both gelatinase A and B. Zymographic analysis showed that human melanoma primarily secretes the gelatinase-A activity, which showed changes similar to those seen in the corresponding mRNA after the treatments with interferons. The expression of gelatinase-B activity was, however, detectable only transiently during the stimulating phase with IFN-alpha. Western immunoblot analysis showed that alterations in the levels of immunoreactive protein of gelatinase A in the cells correlated with the mRNA levels after the treatments. These findings suggest that IFN-alpha and IFN-gamma are potent regulators of both M(r) 72,000 and M(r) 92,000 type-IV collagenase/gelatinase A and B genes in human melanoma showing biphasic and parallel effects on mRNA levels of both enzymes, depending on the treatment time, and that the M(r) 72,000 metalloproteinase/gelatinase A is the predominant basement-membrane-degrading type-IV collagenase in human melanoma.

The induction of 72-kD gelatinase in T cells upon adhesion to endothelial cells is VCAM-1 dependent

T cell extravasation from the bloodstream into the perivascular tissue during inflammation involves transmigration through the endothelial cell layer and basement membrane into the interstitial matrix. The specific mechanisms by which T cells transmigrate, however, are poorly understood. Matrix degradation by enzymes such as 72-kD gelatinase has been implicated as an important component in tissue invasion by various types of cells. In this study, we have demonstrated that 72-kD gelatinase is induced in T cells upon adhesion to endothelial cells. We also provide evidence that the induction of 72-kD gelatinase is mediated by binding to vascular cell adhesion molecule-1 (VCAM-1). The T cells used in this study were cloned murine Th1 cells antigenic to myelin basic protein. These cells express very late antigen-4 on their cell surface and have been shown to infiltrate the brain parenchyma and cause experimental autoimmune encephalomyelitis when infused into normal mice (Baron, J. L., J. A. Madri, N. H. Ruddle, G. Hashim, and C. A. Janeway. 1993. J. Exp. Med. 177:57-68). In the experiments presented here, T cells were cocultured with VCAM-1-positive and -negative endothelial cells grown in a monolayer in order to study the expression of 72-kD gelatinase upon T cell adhesion. Additional experiments were conducted in which T cells were cocultured with VCAM-1 positive cells grown on microporous membranes suspended in transwells to study 72-kD gelatinase following T cell transmigration. T cells were also incubated with recombinant VCAM-1 in order to study the role of VCAM-1 in inducing 72-kD gelatinase. The results demonstrated that T cells adhered to both VCAM-1-positive and -negative endothelial cells. T cells that adhered to the VCAM-1-positive endothelial cells exhibited an induction in 72-kD gelatinase protein, activity, and mRNA whereas 72-kD gelatinase was not induced in the T cells that adhered to the VCAM-1-negative endothelial cells. Incubating T cells with recombinant VCAM-1 coated onto tissue culture plastic showed that T cells adhered to the molecule and that adhesion to recombinant VCAM-1 was sufficient to induce 72-kD gelatinase. Further, T cells that had transmigrated through a VCAM-1-positive endothelial cell monolayer exhibited 72-kD gelatinase activity but not mRNA expression. In addition, 72-kD gelatinase was detected on the cell surface of the transmigrated T cells by FACS analysis. In other experiments, TIMP-2 was added to the transmigration studies and was shown to reduce T cell transmigration.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunohistochemical localization of matrix metalloproteinase 2 and its specific inhibitor TIMP-2 in neoplastic tissues with monoclonal antibodies

Matrix metalloproteinase-2 (MMP-2), synthesized as a 631 amino-acid proenzyme, is activated by cleavage of the first 80 amino acids and naturally inhibited by tissue inhibitor of metalloproteinase-2 (TIMP-2). We report here the production of MAbs against MMP-2 and TIMP-2 and their use in localizing the respective antigens on tumor tissues. The anti-MMP-2 MAb recognized the latent and activated MMP-2 mutant protein (mutein) with C-terminal deletion at amino acid 425, indicating that both N- and C-terminal amino acids of MMP-2 are not important for its binding. The binding study of anti-TIMP-2 MAb, using several C-terminally truncated TIMP-2 muteins, showed that the amino acids 111-126 of TIMP-2 are essential for the binding of this antibody. Besides their respective antigens, both MAbs also recognized the MMP-2/TIMP-2 complex. On frozen sections of breast tumor, anti-MMP-2 MAb stained mainly tumor-cell cytoplasm with varying intensity, while anti-TIMP-2 MAb gave a stromal staining of varying intensity and a weak or absent staining of tumor-cell cytoplasm, suggesting different localization of the proteins in these tumors. In addition, in 1/3 of the breast cases both antibodies also localized on tumor-cell membranes. Similar cytoplasmic and stromal but not membrane staining patterns were observed in colon, gastric, endometrial, squamous-cell, prostatic and ovarian carcinoma as well. Since MMP-2 degrades type-IV collagen, the major component of basement membranes, the differences between MMP-2 and TIMP-2 levels and localization in individual tumors may relate to the invasiveness of the tumor and thus provide predictive information. However, this aspect could not be discussed in this study because no biological and clinical parameters such as lymph-node involvement or Dukes' stage of the tumors were available.