Roopali Roy

Matrix metalloproteinases as novel biomarkers and potential therapeutic targets in human cancer.

The matrix metalloproteinase (MMP) family of enzymes is comprised of critically important extracellular matrix remodeling proteases whose activity has been implicated in a number of key normal and pathologic processes. The latter include tumor growth, progression, and metastasis as well as the dysregulated angiogenesis that is associated with these events. As a result, these proteases have come to represent important therapeutic and diagnostic targets for the treatment and detection of human cancers. In this review, we summarize the literature that establishes these enzymes as important clinical targets, discuss the complexity surrounding their choice as such, and chronicle the development strategies and outcomes of their clinical testing to date. The status of the MMP inhibitors currently in US Food and Drug Administration approved clinical trials is presented and reviewed. We also discuss the more recent and successful targeting of this enzyme family as diagnostic and prognostic predictors of human cancer, its status, and its stage. This analysis includes a wide variety of human cancers and a number of human sample types including tissue, plasma, serum, and urine.

ADAM 12 Cleaves Extracellular Matrix Proteins and Correlates with Cancer Status and Stage

ADAM 12 is a member of a family of disintegrin-containing metalloproteases that have been implicated in a variety of diseases including Alzheimers disease, arthritis, and cancer. We purified ADAM 12 from the urine of breast cancer patients via Q-Sepharose anion exchange and gelatin-Sepharose affinity chromatography followed by protein identification by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Four peptides were identified that spanned the amino acid sequence of ADAM 12. Immunoblot analysis using ADAM 12-specific antibodies detected an ∼68-kDa band identified as the mature form of ADAM 12. To characterize catalytic properties of ADAM 12, full-length ADAM 12-S was expressed in COS-7 cells and purified. Substrate specificity studies demonstrated that ADAM 12-S degrades gelatin, type IV collagen, and fibronectin but not type I collagen or casein. Gelatinase activity of ADAM 12 was completely abrogated by zinc chelators 1,10-phenanthroline and EDTA and was partially inhibited by the hydroxamate inhibitor Marimastat. Endogenous matrix metalloprotease inhibitor TIMP-3 inhibited activity. To validate our initial identification of this enzyme in human urine, 117 urine samples from breast cancer patients and controls were analyzed by immunoblot. The majority of samples from cancer patients were positive for ADAM 12 (67 of 71, sensitivity 0.94) compared with urine from controls in which ADAM 12 was detected with significantly lower frequency. Densitometric analyses of immunoblots demonstrated that ADAM 12 protein levels were higher in urine from breast cancer patients than in control urine. In addition, median levels of ADAM 12 in urine significantly increased with disease progression. These data demonstrate for the first time that ADAM 12 is a gelatinase, that it can be detected in breast cancer patient urine, and that increased urinary levels of this protein correlate with breast cancer progression. They further support the possibility that detection of urinary ADAM 12 may prove useful in the development of noninvasive diagnostic and prognostic tests for breast and perhaps other cancers.

Microdeformational wound therapy: effects on angiogenesis and matrix metalloproteinases in chronic wounds of 3 debilitated patients.

The vacuum-assisted closure (VAC) device causes microdeformations of the wound surface in contact with the foam. Because angiogenesis and matrix metalloproteinase (MMP) activity are altered in chronic wounds, we hypothesized that microdeformations stimulate capillary formation and affect MMP activity. A VAC device was used to deliver microdeformational wound therapy (MDWT) to the chronic wounds of 3 debilitated patients. Debrided tissue was obtained from wound areas with and without foam contact. Microvessel density and MMP activity were determined by immunohistochemistry and zymography, respectively. Microvessel density of MDWT-treated wounds was 4.5% (±0.8) compared with areas not covered by foam [1.6% (±0.1)] (P = 0.05) during the first week of treatment and 2.7% (±0.3) compared with untreated tissue [1.3% (±0.1)] (P = 0.03) during the second treatment week. Wounds subjected to MDWT had greater microvessel density compared with the same wound prior to treatment [1.5% (±0.3)] (P = 0.02). MMP-9/NGAL (neutrophil gelatinase-associated lipocalin), MMP-9, latent MMP-2, and active MMP-2 were reduced by 15%–76% in MDWT-treated wounds. MDWT provides a favorable wound-healing environment by increasing angiogenesis and decreasing MMP activity in chronic wounds.

Tumor-Specific Urinary Matrix Metalloproteinase Fingerprinting: Identification of High Molecular Weight Urinary Matrix Metalloproteinase Species

Purpose: We have previously reported that matrix metalloproteinases MMP-2, MMP-9, and the complex MMP-9/NGAL can be detected in urine of patients with a variety of cancers including prostate and bladder carcinoma. In addition, we also detected several unidentified urinary gelatinase activities with molecular weights >125 kDa. The objective of the current study was to identify these high molecular weight (HMW) species, determine their potential as predictors of disease status, and ask whether a tumor-specific pattern existed based on urinary MMP analysis. Experimental Design: Chromatography, zymography, and mass spectrometry was used to identify HMW gelatinase species of ∼140, 190, and >220 kDa in urine of cancer patients. To determine whether a tumor-specific pattern of appearance existed among the MMPs detected, we analyzed the urine of 189 patients with prostate or bladder cancer and controls. Results: The ∼140, >220 kDa, and ∼190 HMW gelatinase species were identified as MMP-9/tissue inhibitor of metalloproteinase 1 complex, MMP-9 dimer, and ADAMTS-7, respectively. The frequency of detection of any MMP species was significantly higher in urine from prostate and bladder cancer groups than controls. MMP-9 dimer and MMP-9 were independent predictors for distinguishing between patients with prostate and bladder cancer (P < 0.001 for each) by multivariable analysis. Conclusions: This study is the first to identify a tumor-specific urinary MMP fingerprint that may noninvasively facilitate identification of cancer presence and type. This information may be of diagnostic and prognostic value in the detection and/or clinical monitoring of disease progression and therapeutic efficacy in patients with bladder or prostate cancer.

Urinary Metalloproteinases: Noninvasive Biomarkers for Breast Cancer Risk Assessment

Matrix metalloproteinases (MMP) and a disintegrin and metalloprotease 12 (ADAM 12) can be detected in the urine of breast cancer patients and provide independent prediction of disease status. To evaluate the potential of urinary metalloproteinases as biomarkers to predict breast cancer risk status, urine samples from women with known risk marker lesions, atypical hyperplasia and lobular carcinoma in situ (LCIS), were analyzed. Urine samples were obtained from 148 women: 44 women with atypical hyperplasia, 24 women with LCIS, and 80 healthy controls. MMP analysis was done using gelatin zymography and ADAM 12 analysis was done via immunoblotting with monospecific antibodies and subsequent densitometric measurement. Positive urinary MMP-9 levels indicated a 5-fold risk of atypical hyperplasia and >13-fold risk of LCIS compared with normal controls. Urinary ADAM 12 levels were significantly elevated in women with atypical hyperplasia and LCIS from normal controls, with receiver operating characteristic curve analysis showing an area under the curve of 0.914 and 0.950, respectively. To assess clinical applicability, a predictive index was developed using ADAM 12 in conjunction with Gail risk scores for women with atypia. Scores above 2.8 on this ADAM 12-Gail risk prediction index score are predictive of atypical hyperplasia (sensitivity, 0.976; specificity, 0.977). Our data suggest that the noninvasive detection and analysis of urinary ADAM 12 and MMP-9 provide important clinical information for use as biomarkers in the identification of women at increased risk of developing breast cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1034–12)

ADAM12 Transmembrane and Secreted Isoforms Promote Breast Tumor Growth A DISTINCT ROLE FOR ADAM12-S PROTEIN IN TUMOR METASTASIS

Increased levels of ADAM12 have been reported in a variety of human cancers. We have previously reported that urinary ADAM12 is predictive of disease status in breast cancer patients and that ADAM12 protein levels in urine increase with progression of disease. On the basis of these findings, the goal of this study was to elucidate the contribution of ADAM12 in breast tumor growth and progression. Overexpression of both the ADAM12-L (transmembrane) and ADAM12-S (secreted) isoforms in human breast tumor cells resulted in a significantly higher rate of tumor take and increased tumor size. Cells expressing the enzymatically inactive form of the secreted isoform, ADAM12-S, had tumor take rates and tumor volumes similar to those of wild-type cells, suggesting that the tumor-promoting activity of ADAM12-S was a function of its proteolytic activity. Of the two isoforms, only the secreted isoform, ADAM12-S, enhanced the ability of tumor cells to migrate and invade in vitro and resulted in a higher incidence of local and distant metastasis in vivo. This stimulatory effect of ADAM12-S on migration and invasion was dependent on its catalytic activity. Expression of both ADAM12 isoforms was found to be significantly elevated in human malignant breast tissue. Taken together, our results suggest that ADAM12 overexpression results in increased tumor take, tumor size, and metastasis in vivo. These findings suggest that ADAM12 may represent a potential therapeutic target in breast cancer.

A critical role for matrix metalloproteinases in liver regeneration.

BACKGROUND Matrix metalloproteinases (MMPs), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) are mediators of liver regeneration. To determine whether MMPs are required for normal hepatic regeneration, we performed 67% hepatectomies on mice treated with a broad-spectrum MMP-inhibitor, and assessed the effect on liver regeneration and urinary MMP activity. METHODS Mice were subjected to sham operations, 67% hepatectomy, or 67% hepatectomy plus treatment with the broad-spectrum MMP inhibitor Marimastat. Urine collected preoperatively and for 8 d postoperatively was tested for MMP-2 and MMP-9 activity using zymography. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin, TNF-alpha, IL-6, and hepatocyte growth factor levels were measured. Liver sections were analyzed by CD31 immunohistochemistry and microvessel density. Mitotic index and proliferating cell nuclear antigen labeling index were determined. RESULTS The mean regenerating liver weight on postoperative day 8 was 0.72 +/- 0.01 grams for the hepatectomy Marimastat group, and 0.83 +/- 0.02 grams for the hepatectomy control group (P < 0.001). Urinary MMP-9 activity was elevated during hepatic regeneration, and decreased on postoperative day 8 when the liver returned to its preoperative mass. In contrast, urine from hepatectomy Marimastat mice, in which liver regeneration was successfully inhibited, showed consistently low levels of MMP-2 and MMP-9 activity. The hepatectomy Marimastat group also exhibited elevated serum IL-6 levels on post-operative day 8, while serum TNF-alpha soluble receptor II levels were unchanged. Hepatocyte growth factor levels were not significantly different between the control hepatectomy and hepatectomy Marimastat groups at days 2, 4, and 8. Liver microvessel density was reduced in the hepatectomy Marimastat group at day 4. Mitotic index and proliferating cell nuclear antigen index were significantly decreased in the Marimastat hepatectomy group at post-operative day 2. CONCLUSIONS The broad-spectrum MMP-inhibitor Marimastat inhibits liver regeneration. Microvessel density is reduced at day 4. Furthermore, urinary MMP-9 is elevated during liver regeneration, and this effect is not observed when regeneration is inhibited by the broad-spectrum MMP-inhibitor Marimastat.

Potential of Fluorescent Metalloproteinase Substrates for Cancer Detection

OBJECTIVES MMP-2, MMP-9, their complexes and ADAM12 are detected in the urine of breast cancer patients and predict disease status. We assessed the use of FRET-based substrates in an assay to distinguish breast cancer patients from controls. DESIGN AND METHODS Substrates with varying specificities for MMP-9 and MMP-2 and several ADAMs were screened. Flsub21 and Flsub13, substrates for ADAM12 and ADAM8 respectively, were studied. RESULTS Flsub21 and Flsub13 cleavage activities were detected in the urine of patients with invasive and metastatic breast cancers at significantly higher frequencies compared to controls. Our model predicted probabilities of 90% when both Flsub21 and Flsub13 were positive, 65% when Flsub21 alone was positive, 55% when Flsub13 alone was positive and 20% when both substrates were negative. CONCLUSIONS These data suggest the potential utility of FRET substrates to non-invasively identify invasive and/or metastatic breast cancer.

Urinary TIMP-1 and MMP-2 levels detect the presence of pancreatic malignancies

Background:A majority of patients with pancreatic malignancies, including both pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumours (pNETs), present with advanced disease due to a lack of specific symptoms and current diagnostic limitations, making this disease extremely difficult to detect. Our goal was to determine whether urinary matrix metalloproteases (uMMPs) and/or their endogenous inhibitors, urinary tissue inhibitor of metalloproteases (uTIMPs), could be detected in the urine of patients with pancreatic malignancies and whether they may serve as independent predictors of disease status.Methods:Retrospective analyses of urine samples (n=139) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary MMP-2 and uTIMP-1 levels were determined using ELISA and zymography. Biomarker expression in tumour and normal pancreatic tissues was analysed via immunohistochemistry (IHC).Results:Multivariable logistic regression analyses indicated that, when controlling for age and sex, uMMP-2 (P<0.0001) and uTIMP-1 (P<0.0001) but not uMMP-9, were significant independent predictors for distinguishing between PDAC patients and healthy controls. Our data also indicated that uMMP-2 was an independent predictor of the presence of pNET. In addition, uTIMP-1 levels could differentiate the two cancer groups, PDAC and pNET, respectively. Immunohistochemistry analysis confirmed that MMP-2 and TIMP-1 protein expression is significantly upregulated in PDAC tissue compared with the normal pancreas.Conclusions:Taken together, our results suggest that the detection of uMMP-2 and uTIMP-1 may have diagnostic value in the detection of pancreatic malignancies and that uTIMP-1 may be useful in distinguishing between pancreatic adenocarcinoma and neuroendocrine tumours.

The Anti-angiogenic Peptide, Loop 6, Binds Insulin-like Growth Factor-1 Receptor

Tissue inhibitors of metalloproteinases (TIMPs), the endogenous inhibitors of matrix metalloproteinases, have been shown to possess biological functions that are independent of their ability to inhibit matrix metalloproteinases. We have previously shown that the C-terminal domain of TIMP-2 and, in particular, Loop 6 inhibit capillary endothelial cell proliferation and angiogenesis both in vitro and in vivo. To elucidate the mechanism by which Loop 6 inhibits angiogenesis, we sought to determine whether its biological effects were the result of a known TIMP-2 protein-protein interaction or of a receptor-mediated event. In this study, we identify insulin-like growth factor-1 receptor as a binding partner of Loop 6/TIMP-2 and characterize this interaction on the endothelial cell surface and the consequences of this interaction on downstream receptor signaling.