Biomedical subjects

R Fridman

Publications and source records attributed to R Fridman.

At least 37 records · Page 2Linked to original sources

PubMed1998

Matrix metalloproteinases: structures, evolution, and diversification.

A comprehensive sequence alignment of 64 members of the family of matrix metalloproteinases (MMPs) for the entire sequences, and subsequently the catalytic and the hemopexin-like domains, have been performed. The 64 MMPs were selected from plants, invertebrates, and vertebrates. The analyses disclosed that as many as 23 distinct subfamilies of these proteins are known to exist. Information from the sequence alignments was correlated with structures, both crystallographic as well as computational, of the catalytic domains for the 23 representative members of the MMP family. A survey of the metal binding sites and two loops containing variable sequences of amino acids, which are important for substrate interactions, are discussed. The collective data support the proposal that the assembly of the domains into multidomain enzymes was likely to be an early evolutionary event. This was followed by diversification, perhaps in parallel among the MMPs, in a subsequent evolutionary time scale. Analysis indicates that a retrograde structure simplification may have accounted for the evolution of MMPs with simple domain constituents, such as matrilysin, from the larger and more elaborate enzymes.

Amino Acid Sequence↗

PubMed1998

Matrix metalloproteinase-9 expression in bladder washes from bladder cancer patients predicts pathological stage and grade.

The matrix metalloproteinases (MMPs), in particular the gelatinases (MMP-2 and MMP-9) have been associated with tumor cell invasion and metastasis in many human cancers. Here we examined the expression of proMMP-2 (gelatinase A) and proMMP-9 (gelatinase B) proteins in the cellular component of bladder washes obtained from 65 patients. Twenty-six patients had active bladder cancer, 24 had a history of bladder cancer but no evidence of active disease at the time of cystoscopy (recurrence-free), and 15 patients had lesions other than bladder cancer (controls). The results were correlated with the cytological findings of the bladder wash and the histopathological results of the tumor resection when performed. In patients with active transitional cell carcinoma of the bladder, 71 and 38% had expression and overexpression of the latent form of MMP-9 (proMMP-9), respectively. In contrast, neither latent nor active MMP-2 could be detected in any of the samples examined, regardless of tumor status. Overexpression of proMMP-9 correlated with higher grade (P = 0.003) and pathological stage (P = 0.04) of disease in the active bladder cancer group. No significant gelatinase expression was detected in the recurrence-free and control cases. Compared with urine cytology, proMMP-9 expression had an overall higher sensitivity for bladder cancer identification (71 versus 54%, P = 0.11). Detection of proMMP-9 in bladder washes may be a novel approach for the identification of patients with more aggressive forms of bladder cancer.

Adult↗

PubMed1997

Kinetic analysis of the binding of human matrix metalloproteinase-2 and -9 to tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2.

The dissociation constants (Kd) of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 for the active and latent forms of matrix metalloproteinase (MMP)-2 and MMP-9 were evaluated using surface plasmon resonance (SPR) and enzyme inhibition studies. SPR analysis shows biphasic kinetics with high (nM) and low (microM) affinity binding sites of TIMP-2 and TIMP-1 for MMP-2 (72- and 62-kDa species) and MMP-9 (92- and 82-kDa species), respectively. In contrast, binding data of TIMP-2 to an MMP-2 45-kDa active form lacking the C-terminal domain and to an MMP-2 C-terminal domain (CTD) fragment displays monophasic kinetics with Kd values of 315 and 60 nM, respectively. This suggests that the CTD contains the high affinity binding site, whereas the catalytic domain contains the low affinity site. Also, binding of TIMP-2 to pro-MMP-2 is stronger at both the high and low affinity sites than the corresponding binding of TIMP-2 to the MMP-2 62-kDa form demonstrating the importance of the N-terminal prodomain. In addition, the Kd value of TIMP-1 for the MMP-2 62-kDa species is 28. 6 nM at the high affinity site, yet neither the MMP-2 45-kDa species nor the CTD interacts with TIMP-1. Enzyme inhibition studies demonstrate that TIMPs are slow binding inhibitors with monophasic inhibition kinetics. This suggests that a single binding event results in enzyme inhibition. The kinetic parameters for the onset of inhibition are fast (kon approximately 10(5) M-1 s-1) with slow off rates (koff approximately 10(-3) s-1). The inhibition constants (Ki) are in the 10(-7)-10(-9) M range and correlate with the values determined by SPR.

Biosensing Techniques↗

PubMed1997

Phorbol ester-induced cell surface association of matrix metalloproteinase-9 in human MCF10A breast epithelial cells.

Cell surface association of extracellular matrix (ECM)-degrading enzymes has been suggested to facilitate proteolysis of ECM in areas of cell-matrix contacts and to be crucial for the process of tumor cell invasion. Matrix metalloproteinase-9 (MMP-9) is a member of the MMP family of endopeptidases that has been shown to play a critical role in hydrolysis of ECM components and has been localized on the surface of tumor cells. However, the nature of the cell surface association of MMP-9 is unknown. Here, we report the cell surface association of MMP-9 in human breast epithelial MCF10A cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA). Surface biotinylation and immunoprecipitation with anti-MMP-9 antibodies revealed the presence of two MMP-9 forms (M(r) 92,000 and 85,000) on the surface of TPA-treated MCF10A cells, whereas in the media, only the M(r) 92,000 form was detected, mostly in complex with TIMP-1, a specific MMP-9 inhibitor. The MMP-9 forms were also found in purified plasma membranes of TPA-treated cells. In contrast, the plasma membranes contained little or no TIMP-1. The surface-bound MMP-9 forms were recognized by an antibody to the NH2-terminal prodomain, indicating that both represent latent enzymes. Pulse-chase analysis and endoglycosidase H digestion of surface-biotinylated MMP-9 forms demonstrated that the M(r) 85,000 species was endoglycosidase H sensitive, suggesting targeting of the precursor form of MMP-9 to the cell surface. These studies demonstrate a specific cell surface association of MMP-9 in response to TPA that may help to localize TIMP-1-free enzyme on the surface of breast epithelial cells.

Breast↗

PubMed1997

Epidermal growth factor and amphiregulin up-regulate matrix metalloproteinase-9 (MMP-9) in human breast cancer cells.

The EGF family of proteins encompasses several polypeptides such as epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), amphiregulin (AR) and heregulin (HRG-beta 1). These polypeptides regulate proliferation in breast cancer cells through interaction with membrane receptors. It has been previously shown that high EGF receptor number correlates with aggressive behavior and increased metastasis in human breast cancer. In the present study, we investigated the association between EGF and EGF-like ligand-induced DNA synthesis and secretion of MMP-9 and MMP-2 in metastatic SKBR-3 and non-metastatic MCF-7 breast cancer cells. Exposure of SKBR-3 cells to EGF or AR induces expression of MMP-9 but has no effect on MMP-2 secretion. In contrast to EGF and AR, HRG had no effect on gelatinase induction. None of the EGF polypeptides had any effect on gelatinase induction in MCF-7 non-metastatic breast cancer cells. While a relatively specific inhibitor of EGF receptor tyrosine kinase, PD 153035, inhibited EGF-, AR- and HRG-induced cell proliferation, it had no effect on MMP-9 induced by EGF and AR. Experimental evidence suggests that signaling mechanisms for cell proliferation and MMP-9 induction are mediated by different pathways down-stream of EGF receptor autophosphorylation or that low levels of EGF-induced signal that escape inhibition are sufficient to induce MMP-9 but unable to support cell proliferation. In addition, our results suggest that EGF and AR may modulate invasion of metastatic breast cancer cells by increasing the expression of MMPs.

Amphiregulin↗

PubMed1997

In vivo characterization of host and bacterial protease expression during Pseudomonas aeruginosa corneal infections in naive and immunized mice.

PURPOSE: The corneal destruction resulting from P. aeruginosa keratitis is thought to be due, in part, to the actions of host and bacterial proteases on corneal tissue. The intent of the current study was to compare host and bacterial protease expression in the ocular tissues of mice that have been shown to be susceptible to corneal infection with mice that have been protected from such infection as a result of prior immunization. METHODS: Supernatants of infected corneal homogenates from naive mice or from mice immunized as a result of prior corneal infection or that had been immunized against bacterial protease were analyzed by gelatin zymography for the presence of host gelatinases and bacterial proteases at various times after infection. In addition, studies were carried out to examine the effect of immunization with bacterial protease on numbers of ocular bacteria. RESULTS: Mice that were protected against the tissue destruction during infection were found to have reduced proteolytic activity in corneal tissues when compared with susceptible mice. More specifically, the resistant mice displayed lower levels of bacterial alkaline protease, latent MMP-2, and both the active and latent forms of MMP-9. In addition, immunization against either bacterial alkaline protease or elastase failed to reduce bacterial numbers in ocular tissues from 6 to 72 hours after infection. CONCLUSIONS: These results suggest that increased proteolytic activity in ocular tissues during P. aeruginosa infection may contribute to the irreversible corneal damage observed during the infection.

Animals↗

PubMed1996

Carbohydrate-mediated regulation of matrix metalloproteinase-2 activation in normal human fibroblasts and fibrosarcoma cells.

Matrix metalloproteinase-2 (MMP-2) is activated on the cell surface by membrane type 1-MMP (MT1-MMP). Activation of proMMP-2 is induced in vitro by concanavalin A (ConA). The regulation of proMMP-2 activation is, however, not yet fully understood. We investigated the effect of plant lectins, carbohydrates and inhibitors of the cytoskeleton on proMMP-2 activation in normal (HLF1) and malignant fibroblast (HT1080) cells. Native ConA induced proMMP-2 activation in both cell types while dimeric succinyl-ConA had no effect, suggesting that receptor clustering is involved in activation. Wheat germ agglutinin (WGA) also induced proMMP-2 activation. N-acetyl-D-glucosamine (GlcNac) inhibited the effects of ConA and WGA while mannose only inhibited ConA-induced proMMP-2 activation. Mannose also inhibited the expression of MT1-MMP mRNA induced by ConA. Cytochalasin B and colchicine had no effect on the ConA induction of proMMP-2 activation. These studies help to define some of the cellular and molecular mechanisms for the induction of proMMP-2 activation.

Acetylgalactosamine↗

PubMed1996

Expression of functional recombinant human procathepsin B in mammalian cells.

Cathepsin B has been implicated in numerous pathobiological processes. In order to study its interactions with other proteins implicated in these processes, quantities of functional recombinant cathepsin B are needed. Therefore, we expressed recombinant human procathepsin B in mammalian cells (BSC-1 monkey kidney cells and HeLa human cervical carcinoma cells) using a vaccinia virus expression system. The recombinant human procathepsin B appeared to be authentic and expressed in its native conformation as indicated by: (1) N-terminal sequencing; (2) molecular size; (3) processing intracellularly to mature double-chain cathepsin B; (4) in vitro cleavage by pepsin to mature cathepsin B coincident with appearance of activity against a selective synthetic substrate; and (5) substrate/inhibitor profiles. This is the first report of the expression of functional recombinant human procathepsin B in mammalian cells. We also report a single-step immunoaffinity purification procedure for the isolation of electrophoretically pure proenzyme. By the methodologies described, human procathepsin B can now be obtained in high yield. This should facilitate studies of its interactions with protease inhibitors, other proteases, extracellular matrices, cell-surface proteins and biological substrates that may be of relevance to the pathobiological functions of this enzyme.

Adenocarcinoma↗

PubMed1996

Matrix metalloproteinase 2 releases active soluble ectodomain of fibroblast growth factor receptor 1.

Recent studies have demonstrated the existence of a soluble fibroblast growth factor (FGF) receptor type 1 (FGFR1) extracellular domain in the circulation and in vascular basement membranes. However, the process of FGFR1 ectodomain release from the plasma membrane is not known. Here we report that the 72-kDa gelatinase A (matrix metalloproteinase type 2, MMP2) can hydrolyze the Val368-Met369 peptide bond of the FGFR1 ectodomain, eight amino acids upstream of the transmembrane domain, thus releasing the entire extracellular domain. Similar results were obtained regardless of whether FGF was first bound to the receptor or not. The action of MMP2 abolished binding of FGF to an immobilized recombinant FGFR1 ectodomain fusion protein and to Chinese hamster ovary cells overexpressing FGFR1 The released recombinant FGFR1 ectodomain was able to bind FGF after MMP2 cleavage, suggesting that the cleaved soluble receptor maintained its FGF binding capacity. The activity of MMP2 could not be reproduced by the 92-kDa gelatinase B (MMP9) and was inhibited by tissue inhibitor of metalloproteinase type 2. These studies demonstrate that FGFR1 may be a specific target for MMP2 on the cell surface, yielding a soluble FGF receptor that may modulate the mitogenic and angiogenic activities of FGF.

Amino Acid Sequence↗

PubMed1996

High levels of tissue inhibitor of metalloproteinase-2 (TIMP-2) expression are associated with poor outcome in invasive bladder cancer.

The matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs) have been associated with tumor invasion and metastasis in many human cancers. Immunohistochemical studies were performed on frozen tumor samples from 42 patients with invasive bladder cancer treated by cystectomy with monoclonal antibodies against the Mr 72,000 gelatinase A (MMP-2), Mr 92,000 gelatinase B (MMP-9), and TIMP-2 to evaluate their significance in bladder cancer. Immunoreactivity for the gelatinases was predominantly tumor cell-associated, whereas strong TIMP-2 staining was mostly detected in the stroma. Tumor cells demonstrated moderate to strong reactivity for MMP-2 and MMP-9 in 71 and 71% of cases, respectively, which did not correlate with stage, grade, or outcome. Tumor cells were positive for TIMP-2 in 26 (62%) of 42 cases, and this correlated with a worse outcome (69 versus 25% died of disease; P < 0.05). In 31 (74%) of 42, there was moderate to strong stromal staining for TIMP-2; this also was associated with a poor outcome (65 versus 25% died of cancer; P < 0.05). Tumor basement membrane (BM) status was investigated using an antibody to type IV collagen. In 9 cases, the invasive tumor nests were surrounded by an intact BM; in 7 of these, stromal staining for TIMP-2 was absent. None of these 9 patients (0%) died of tumors compared with 7 (100%) of 7 with complete loss of BM staining (P < 0.001). These results suggest a potential role for TIMP-2 and BM staining as prognostic indicators in invasive bladder cancer.

Adult↗

PubMed1996

Consequences of functional expression of the plasma membrane Ca2+ pump isoform 1a.

The plasma membrane Ca2+-ATPase pump (PMCA) is an integral component of the Ca2+ signaling system which participates in signal transduction during agonist stimulated cell activation. To better understand the physiological function of the pump, isoform 1a (PMCA1a) was over-expressed in rat aortic endothelial cells using a stable transfection system under the control of a cytomegalovirus promoter. The cell lines selected after transfection with PMCA1a construct, expressed 3-4-fold increased pump protein which was mostly targeted to the plasma membrane as indicated by immunoperoxidase staining. Ca2+ uptake assays in a membrane preparation indicated a 3-4-fold increase in Ca2+ pumping activity in the transfected cells, and the expressed PMCA1a showed typical dependence on Ca2+ and calmodulin for stimulation of activity. Measurement of [Ca2+]i and [Ca2+]out showed that expression of PMCA1a had a profound effect on different aspects of the Ca2+ signal. The peak increase in [Ca2+]i evoked by ATP and/or thapsigargin was lower but the plateau phase was similar in the PMCA1a expressing cells. Accordingly, titration with ionomycin of Ca2+ content of internal stores, measurement of Ca2+ uptake into the thapsigargin- and oxalate-sensitive pool (endoplasmic reticulum) of isolated microsomes, Ca2+ uptake into streptolysin O-permeabilized cells, and analysis of SERCA mRNA and protein, showed that expression and activity of the SERCA pump was down-regulated in cells expressing PMCA1a pump. Expression of PMCA1a also down-regulated expression of the inositol 1,4,5-trisphosphate (IP3)-activated Ca2+ channel and the rate of IP3-mediated Ca2+ release in permeable cells, without affecting the affinity of the channel for IP3. On the other hand the rate of store depletion-dependent Ca2+ and Mn2+ influx (Ca2+ entry) into PMCA1a expressing cells was increased by about 2.6-fold. These changes prevented estimating the rate of pump-mediated Ca2+ efflux from changes in [Ca2+]i. Measurement of [Ca2+]out showed that the rate of Ca2+ efflux in cells expressing PMCA1a was about 1.45-fold higher than Neo controls, despite the 4-fold increase in the amount of functional pump protein. The overall study points to the flexibility, interdependence, and adaptability of the different components of the Ca2+ signaling systems to regulate the expression and activity of each component and maintain a nearly constant Ca2+ signal.

Animals↗

PubMed1995

Activation of progelatinase B (MMP-9) by gelatinase A (MMP-2).

The M(r) 72,000 (MMP-2; gelatinase A) and M(r) 92,000 (MMP-9; gelatinase B) gelatinases are two members of the family of matrix metalloproteinases (MMPs). These proteinases are thought to play a critical role in tumor cell invasion and are frequently coexpressed in human cancers. Gelatinases are secreted in a latent inactive form, and their conversion to the active species can be accomplished by other proteolytic enzymes, including other MMPs. We report herein that organomercurial or plasma membrane-activated M(r) 72,000 gelatinase A activates progelatinase B to an M(r) 82,000 active form in a process inhibited by tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Progelatinase B activation was accomplished by the two active species of gelatinase A, the M(r) 62,000 and M(r) 45,000 forms, generated after plasma membrane or organomercurial activation of TIMP-2-free progelatinase A. The M(r) 45,000 species of gelatinase A lacks both the NH2-terminal profragment and the COOH-terminal domain known to play a role in plasma membrane activation and the regulation of TIMP-2 inhibition. These results suggest a novel mechanism of activation of progelatinase B mediated by gelatinase A species that may be localized in the surface of tumor cells and enhance matrix degradation during cancer metastasis.

Amino Acid Sequence↗

PubMed1995

The extracellular matrix produced by bovine corneal endothelial cells contains progelatinase A.

Progelatinase A is a matrix metalloproteinase involved in the turnover of extracellular matrix (ECM). We report that the ECM produced by bovine corneal endothelial (BCE) cells contains progelatinase A free of tissue inhibitor of metalloproteinase (TIMP2). The matrix-bound progelatinase A can be activated by APMA to generate a 62 kDa and a 45 kDa species with enzymatic activity and is inhibited by TIMP2. The bound progelatinase can be released after treatment of the ECM with gelatinase B. These studies suggest that the ECM can function as a reservoir for progelatinase A which may be readily available for cells in processes such as metastasis, angiogenesis, inflammation and wound healing.

Animals↗

PubMed1995

The effect of platelets on invasiveness and protease production of human mammary tumor cells.

Interaction of tumor cells with platelets facilitates metastasis of tumor cells. It has been proposed that platelets protect tumor cells against the host's immune defense and enhance tumor-cell extravasation. In the present work we show that platelets increase the invasiveness of 3 mammalian cell lines (MCF-7, ZR-51 and MDA-MB231) through extracellular matrix, and propose this as an additional mechanism by which platelets facilitate metastasis. Since gelatinase and urokinase have both been implicated in degradation of the extracellular matrix and cell migration, and therefore in tumor invasion, we have also analyzed whether the interaction of platelets with tumor cells can modify the secretion of these proteases by tumor cells. MDA-MB231, which was the most invasive cell line among the 3 tested and was the most potent in inducing platelet aggregation, secreted the highest level of urokinase and was the only one in which gelatinase was detected. While platelets had no significant effect on the urokinase activity expressed by these cells, they induced in MDA-MB231 an important increase in the secretion of gelatinase, which can be reproduced by both platelet membrane and platelet releasate of activated platelets. This increase in gelatinase could be responsible, at least in part, for the increased invasiveness of these cells, since added TIMP-1 significantly reduced the number of cells which traversed matrigel.

Blood Platelets↗

PubMed1995

In vivo bacterial protease production during Pseudomonas aeruginosa corneal infection.

PURPOSE: To establish if active pseudomonal proteases are present in vivo during corneal infection with Pseudomonas aeruginosa and to determine if the mouse strains used in these and previous studies have the ability to mount a nonocular antibody response to the purified proteases because antibodies to the bacterial proteases were not detected previously during in vivo ocular infection. METHODS: At certain times after corneal infection with P. aeruginosa, corneas were harvested and supernatants from the corneal homogenates were analyzed for proteolytic activity by zymography and immunoreactivity by immunoblotting. The efficiency of the extraction procedures used in these studies was determined by incubating uninfected corneal homogenates with the purified proteases. The resultant supernatants were analyzed for alkaline protease and elastase activity. Additionally, mice were immunized intraperitoneally with the purified proteases with and without adjuvant to determine if the animals could mount a nonocular antibody response. RESULTS: Corneas infected with P. aeruginosa demonstrated the presence of alkaline protease, but not elastase, by the two methods examined. The kinetics of the in vivo alkaline protease response closely parallels previously reported bacterial clearance studies in that peak alkaline protease activity was detected in corneal tissue when peak bacterial numbers also were observed in the eye, and it was absent when the eyes were sterile or nearly sterile. In addition, C57BL/6J mice were capable of mounting a nonocular antibody response to microgram quantities of both proteases only in the presence of adjuvant. CONCLUSIONS: In the model described, enzymatically active alkaline protease, but not elastase, was demonstrated in corneal tissues during in vivo infection. Concentrations of these proteases were much lower than those required to stimulate an antibody response.

Animals↗

PubMed1994

Proteolysis of A beta peptide from Alzheimer disease brain by gelatinase A.

It has been recently reported that the 72 kDa proteolytic enzyme gelatinase A/type IV collagenase/matrix metalloproteinase 2 (MMP2) hydrolyzed the Lys 16-Leu 17 peptide bond of a synthetic decapeptide (YEVHHQKLVFF) representing the soluble A beta sequence of amino acid residues 10-20. Our aim was to test if this enzyme could also degrade the insoluble 40-42 residues long A beta peptides purified from Alzheimer Disease brain. Our results indicate that MMP2 hydrolyzes A beta 1-40 and A beta 1-42 peptides at Lys 16-Leu 17, at Leu 34-Met 35, and Met 35-Val 36 peptide bonds. These results suggest that MMP2 has the ability of degrading A beta of AD in vitro. If this hydrolysis also occurs in the brain's extracellular matrix, the enzymatic action of gelatinase a could prevent the generation of amyloidogenic A beta 1-40(42).

Alzheimer Disease↗

PubMed1994

Galectin-3 is a novel substrate for human matrix metalloproteinases-2 and -9.

The primary structure of galectin-3, a approximately 30 kDa galactoside-binding protein (aka CBP-35, mL-34, hL-31, L-29, Mac-2, and epsilon BP), reveals two structural domains: an amino-terminal domain consists of a Pro-Gly-rich motif, and a globular carboxyl-terminal domain containing a carbohydrate-binding site. In this study, we report that the amino-terminal domain of galectin-3 contains a cleavage site for two members of the matrix metalloproteinase family of enzymes: the 72 kDa (gelatinase A, MMP-2) and the 92 kDa (gelatinase B, MMP-9) proteinases. The major cleavage site for the gelatinases in galectin-3 is at the Ala62-Tyr63 bond, and its hydrolysis by these enzymes was inhibited by TIMP-2. Cell-surface expression of galectin-3 was reduced following treatment of viable T47D human breast carcinoma cells with gelatinase A. These results suggest that galectin-3 may be a substrate for gelatinases and that its degradation may play a role in modulating the biological activities of galectin-3.

Amino Acid Sequence↗

PubMed1994

Enhanced expression of tissue inhibitor of metalloproteinase-2 (TIMP-2) in the stroma of breast carcinomas correlates with tumor recurrence.

The 72-kDa (MMP-2, gelatinase A) and the 92-kDa (MMP-9, gelatinase B) matrix metalloproteinases have been associated with tumor cell invasion and metastasis. Immunohistological staining of MMP-2 and MMP-9, basal lamina collagen IV and TIMP-2 were performed on frozen sections of 83 invasive breast carcinomas. MMP-2 and MMP-9 were associated with neoplastic cell plasma membrane in 72% of cases and exhibited inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining was not correlated with presence of metastases at time of diagnosis or with disease outcome. TIMP-2 was detected in the peri-tumoral stroma and was present in 87% of cases. Residual benign breast tissue was negative for TIMP-2 staining. Neoplasms with diffuse TIMP-2 staining (24%) recurred significantly more frequently (75% recurred) than cases with focal (42% recurred) or absent (27% recurred) TIMP-2. Presence of collagen IV was negatively correlated with gelatinase staining. We conclude that up-regulation of MMP-2 and MMP-9 expression in breast tumor cells is reciprocally correlated to collagen IV staining. Clinical outcome, however, is more closely related to the presence of TIMP-2 than the corresponding MMPs. Enhanced TIMP-2 expression, therefore, may denote a stromal response to tumor invasion, indicative of aggressive behavior in a subset of breast carcinomas.

Antibodies, Monoclonal↗