Mammary adipocytes promote breast tumor cell invasion and angiogenesis in the context of menopause and obesity.

The mechanism(s) underlying obesity-related postmenopausal (PM) breast cancer (BC) are not clearly understood. We hypothesized that the increased local presence of 'obese' mammary adipocytes within the BC microenvironment promotes the acquisition of an invasive and angiogenic BC cell phenotype and accelerates tumor proliferation and progression. BC cells, treated with primary mammary adipocyte secretome from premenopausal (Pre-M) and PM obese women (ObAdCM; obese adipocyte conditioned-media) upregulated the expression of several pro-tumorigenic factors including VEGF, lipocalin-2 and IL-6. Both Pre-M and PM ObAdCM stimulated endothelial cell recruitment and proliferation and significantly stimulated BC cell proliferation, migration and invasion. IL-6 and LCN2 induced STAT3/Akt signaling in BC cells and STAT3 inhibition abrogated the ObAdCM-stimulated BC cell proliferation and migration. Expression of proangiogenic regulators including VEGF, NRP1, NRP2, IL8RB, TGFß2, and TSP-1 were found to be differentially regulated in mammary adipocytes from obese PM women. Comparative RNAseq indicated an upregulation of PI3K/Akt signaling, ECM-receptor interactions and lipid/fatty acid metabolism in PM versus Pre-M mammary adipocytes. Our results demonstrate that irrespective of menopausal status, cross-talk between obese mammary adipocytes and BC cells promotes tumor aggressiveness and suggest that targeting the LCN2/IL-6/STAT3 signaling axis may be a useful strategy in obesity-driven breast tumorigenesis.

Escape from breast tumor dormancy: The convergence of obesity and menopause.

Obesity is associated with an increased risk of, and a poor prognosis for, postmenopausal (PM) breast cancer (BC). Our goal was to determine whether diet-induced obesity (DIO) promotes 1) shorter tumor latency, 2) an escape from tumor dormancy, and 3) an acceleration of tumor growth and to elucidate the underlying mechanism(s). We have developed in vitro assays and PM breast tumor models complemented by a noninvasive imaging system to detect vascular invasion of dormant tumors and have used them to determine whether obesity promotes the escape from breast tumor dormancy and tumor growth by facilitating the switch to the vascular phenotype (SVP) in PM BC. Obese mice had significantly higher tumor frequency, higher tumor volume, and lower overall survival compared with lean mice. We demonstrate that DIO exacerbates mammary gland hyperplasia and neoplasia, reduces tumor latency, and increases tumor frequency via an earlier acquisition of the SVP. DIO establishes a local and systemic proangiogenic and inflammatory environment via the up-regulation of lipocalin-2 (LCN2), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) that may promote the escape from tumor dormancy and tumor progression. In addition, we show that targeting neovascularization via a multitargeted receptor tyrosine kinase inhibitor, sunitinib, can delay the acquisition of the SVP, thereby prolonging tumor latency, reducing tumor frequency, and increasing tumor-free survival, suggesting that targeting neovascularization may be a potential therapeutic strategy in obesity-associated PM BC progression. This study establishes the link between obesity and PM BC and, for the first time to our knowledge, bridges the dysfunctional neovascularization of obesity with the earliest stages of tumor development.

Association of Longitudinal Changes in Symptoms and Urinary Biomarkers in Patients with Urological Chronic Pelvic Pain Syndrome: A MAPP Research Network Study.

PURPOSE: We analyzed a series of novel noninvasive urinary biomarkers for their ability to objectively monitor the longitudinal clinical status of patients with urological chronic pelvic pain syndrome. MATERIALS AND METHODS: Baseline, 6 and 12-month urine samples were collected (216) and used to quantify vascular endothelial growth factor, vascular endothelial growth factor (VEGF) receptor 1 (R1), neutrophil gelatinase associated lipocalin (NGAL), matrix metalloproteinase-2, matrix metalloproteinase (MMP)-9, and MMP-9/NGAL complex by enzyme-linked immunosorbent assays. Patient symptom changes were classified as improved, stable or worse using a functional clustering algorithm. Proportional odds models were used to evaluate the association between symptom change and urinary biomarkers. RESULTS: Across all sampled participants, longitudinal decreases in normalized VEGF concentration (pg/µg) were associated with pain severity improvement, and decreases in MMP-9, NGAL and VEGF-R1 concentration (pg/ml) as well as NGAL normalized concentration were associated with improved urinary symptoms. Longitudinal decreases in normalized VEGF-R1 were associated with pain improvement in patients with moderate widespreadness, no bladder symptoms and no painful filling. Lower baseline normalized VEGF-R1 concentration was associated with pain improvement in patients with pelvic pain only. Higher baseline MMP-9/NGAL levels were associated with pain and urinary improvement across all participants. Moreover, longitudinal increases in MMP-2 concentration was associated with improved pain in men and patients with painful filling. CONCLUSIONS: Our results suggest these urinary biomarkers may be useful in monitoring urological chronic pelvic pain syndrome symptom changes with respect to both urinary severity and pain severity. With further testing, they may represent objective biological measures of urological chronic pelvic pain syndrome progression and/or resolution while also providing insight into the pathophysiology of urological chronic pelvic pain syndrome.

Metalloproteinases and their roles in human cancer.

It is now widely appreciated that members of the matrix metalloproteinase (MMP) family of enzymes play a key role in cancer development and progression along with many of the hallmarks associated with them. The activity of these enzymes has been directly implicated in extracellular matrix remodeling, the processing of growth factors and receptors, the modulation of cell migration, proliferation, and invasion, the epithelial to mesenchymal transition, the regulation of immune responses, and the control of angiogenesis. Certain MMP family members have been validated as biomarkers of a variety of human cancers including those of the breast, brain, pancreas, prostate, ovary, and others. The related metalloproteinases, the A disintegrin and metalloproteinases (ADAMs), share a number of these functions as well. Here, we explore these essential metalloproteinases and some of their disease-associated activities in detail as well as some of their complementary translational potential. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Adipocytes promote ovarian cancer chemoresistance.

Ovarian cancer (OvCa), while accounting for only 3% of all women's cancer, is the fifth leading cause of cancer death among women. One of the most significant obstacles to successful OvCa treatment is chemoresistance. The current lack of understanding of the driving mechanisms underlying chemoresistance hinders the development of effective therapeutics against this obstacle. Adipocytes are key components of the OvCa microenvironment and have been shown to be involved in OvCa cell proliferation, however, little is known about their impact on OvCa chemoresistance. In the current study, we found that adipocytes, of both subcutaneous and visceral origin, secrete factors that enhance the resistance of OvCa cells against chemotherapeutic drugs by activating the Akt pathway. Importantly, we have demonstrated that secreted lipids mediate adipocyte-induced chemoresistance. Through a comprehensive lipidomic analysis, we have identified this chemo-protective lipid mediator as arachidonic acid (AA). AA acts on OvCa cells directly, not through its downstream derivatives such as prostaglandins, to activate Akt and inhibit cisplatin-induced apoptosis. Taken together, our study has identified adipocytes and their secreted AA as important mediators of OvCa chemoresistance. Strategies that block the production of AA from adipocytes or block its anti-apoptotic function may potentially inhibit chemoresistance in OvCa patients.

ADAM12 Is a Novel Regulator of Tumor Angiogenesis via STAT3 Signaling.

ADAM12, (ADisintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608-22. ©2017 AACR.

Identification of novel non-invasive biomarkers of urinary chronic pelvic pain syndrome: findings from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network.

OBJECTIVE: To examine a series of candidate markers for urological chronic pelvic pain syndrome (UCPPS), selected based on their proposed involvement in underlying biological processes so as to provide new insights into pathophysiology and suggest targets for expanded clinical and mechanistic studies. METHODS: Baseline urine samples from Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study participants with UCPPS (n = 259), positive controls (PCs; chronic pain without pelvic pain, n = 107) and healthy controls (HCs, n = 125) were analysed for the presence of proteins that are suggested in the literature to be associated with UCPPS. Matrix metalloproteinase (MMP)-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex (also known as Lipocalin 2), vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGF-R1) and NGAL were assayed and quantitated using mono-specific enzyme-linked immunosorbent assays for each protein. Log-transformed concentration (pg/mL or ng/mL) and concentration normalized to total protein (pg/µg) values were compared among the UCPPS, PC and HC groups within sex using the Student's t-test, with P values adjusted for multiple comparisons. Multivariable logistic regression and receiver-operating characteristic curves assessed the utility of the biomarkers in distinguishing participants with UCPPS and control participants. Associations of protein with symptom severity were assessed by linear regression. RESULTS: Significantly higher normalized concentrations (pg/µg) of VEGF, VEGF-R1 and MMP-9 in men and VEGF concentration (pg/mL) in women were associated with UCPPS vs HC. These proteins provided only marginal discrimination between UCPPS participants and HCs. In men with UCCPS, pain severity was significantly positively associated with concentrations of MMP-9 and MMP-9/NGAL complex, and urinary severity was significantly positively associated with MMP-9, MMP-9/NGAL complex and VEGF-R1. In women with UCPPS, pain and urinary symptom severity were associated with increased normalized concentrations of MMP-9/NGAL complex, while pain severity alone was associated with increased normalized concentrations of VEGF, and urinary severity alone was associated with increased normalized concentrations of MMP-2. Pain severity in women with UCPPS was significantly positively associated with concentrations of all biomarkers except NGAL, and urinary severity with all concentrations except VEGF-R1. CONCLUSION: Altered levels of MMP-9, MMP-9/NGAL complex and VEGF-R1 in men, and all biomarkers in women, were associated with clinical symptoms of UCPPS. None of the evaluated candidate markers usefully discriminated UCPPS patients from controls. Elevated VEGF, MMP-9 and VEGF-R1 levels in men and VEGF levels in women may provide potential new insights into the pathophysiology of UCPPS.

Mining the Human Proteome: Biomarker Discovery for Human Cancer and Metastases.

As our knowledge of the mechanisms underlying cancer development and progression has increased, so too have more effective, less toxic, and targeted therapies begun to reach the clinic. However, the full impact of these clinical advances and the practical success of the emerging field of precision medicine are dependent on the discovery and validation of sensitive and accurate biomarkers that can enable appropriate and rigorous sample type and patient selection, reliable longitudinal monitoring of therapeutic efficacy, and even risk assessment and early detection. Within the context of this review, we examine state-of-the-art approaches to the discovery and validation of noninvasive cancer biomarkers, with a specific emphasis on those that are protein or protein-associated ones. We also review sample selection strategies, currently utilized proteomic approaches for both discovery and validation requirements, and data analysis standards. Finally, we provide examples of these elements of biomarker discovery and validation from our own biomarker research.

Novel non-invasive biomarkers that distinguish between benign prostate hyperplasia and prostate cancer.

BACKGROUND: The objective of this study was to discover and to validate novel noninvasive biomarkers that distinguish between benign prostate hyperplasia (BPH) and localized prostate cancer (PCa), thereby helping to solve the diagnostic dilemma confronting clinicians who treat these patients. METHODS: Quantitative iTRAQ LC/LC/MS/MS analysis was used to identify proteins that are differentially expressed in the urine of men with BPH compared with those who have localized PCa. These proteins were validated in 173 urine samples from patients diagnosed with BPH (N = 83) and PCa (N = 90). Multivariate logistic regression analysis was used to identify the predictive biomarkers. RESULTS: Three proteins, ß2M, PGA3, and MUC3 were identified by iTRAQ and validated by immunoblot analyses. Univariate analysis demonstrated significant elevations in urinary ß2M (P < 0.001), PGA3 (P = 0.006), and MUC3 (P = 0.018) levels found in the urine of PCa patients. Multivariate logistic regression analysis revealed AUC values ranging from 0.618 for MUC3 (P = 0.009), 0.625 for PGA3 (P < 0.008), and 0.668 for ß2M (P < 0.001). The combination of all three demonstrated an AUC of 0.710 (95% CI: 0.631 - 0.788, P < 0.001); diagnostic accuracy improved even more when these data were combined with PSA categories (AUC = 0.812, (95% CI: 0.740 - 0.885, P < 0.001). CONCLUSIONS: Urinary ß2M, PGA3, and MUC3, when analyzed alone or when multiplexed with clinically defined categories of PSA, may be clinically useful in noninvasively resolving the dilemma of effectively discriminating between BPH and localized PCa.

ADAM12 induces estrogen-independence in breast cancer cells.

Antiestrogen therapy has been used successfully to prolong disease-free and overall survival of ER positive breast cancer patients. However, 50% of patients with ER+ tumors fail to respond to such therapy or eventually acquire resistance to endocrine therapy, resulting in tumor progression and mortality. It is imperative, therefore, to understand the mechanisms that lead to hormone refractory breast cancer in order to develop therapeutics that can modulate the resistance to antiestrogen therapy. The protease, ADAM12, can be detected in the urine of breast cancer patients and its levels correlate with disease status, stage, and cancer risk. Within the context of this study, the authors have investigated the role of the two distinct isoforms of ADAM12 in breast tumor cell proliferation and as potential mediators of endocrine resistance. Using stable clones of ADAM12-overexpressing MCF-7 cells, the authors analyzed proliferation rates of these ER+ breast tumor cells both in estrogen-depleted medium and in the presence of the antiestrogens, tamoxifen, and ICI 182,780. Acquired estrogen resistance in these cells was analyzed using phospho-RTK analysis. Upregulation and phosphorylation of proteins were detected via immunoprecipitation and immunoblotting. EGFR and MAPK inhibitors were used to explore the mechanism of acquired estrogen resistance in breast tumor cells. It was observed that overexpression of the two isoforms, transmembrane ADAM12-L, and secreted ADAM12-S, in breast tumor cells promoted estrogen-independent proliferation. In ADAM12-L-expressing cells, estrogen-independence was a direct result of increased EGFR expression and MAPK activation, whereas, the mechanism in ADAM12-S-expressing cells may be enhanced IGF-1R signaling. The importance of the EGFR signaling pathway in the estrogen-independent growth of ADAM12-L expressing cells was highlighted by the effect of EGFR inhibitors AG1478 and PD15035 or MAPK inhibitor U0126, each of which abolished the antiestrogen resistance in these cells. Taken together, these results demonstrate that ADAM12 isoforms confer a proliferative advantage to MCF-7 cells in the absence of estrogen stimulation, and suggest that downregulation of ADAM12 in combination with endocrine therapy may represent a useful pharmacological approach to breast cancer therapy.

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.

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.

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.

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.

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 approximately 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 approximately 140, >220 kDa, and approximately 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.

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.

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.

Making the cut: protease-mediated regulation of angiogenesis.

Angiogenesis is an integral element of normal physiologic development as well as of wound healing and a variety of pathologic conditions. Since the earliest studies of the cellular processes required for the formation of new capillaries from preexisting vessels, proteolysis has been recognized as one of the earliest and most sustained activities involved in these events. Several proteases including matrix metalloproteases (MMPs), and the closely related ADAM (a disintegrin and metalloprotease domain) and ADAMTS (a disintegrin and metalloprotease domain with thrombospondin motifs) families, as well as cysteine and serine proteases, have been implicated in this regulation. The current review addresses the contribution of these proteases in the positive and negative regulation of angiogenesis as mediated by degradation of the endothelial basement membrane and extracellular matrix proteins, release of angiogenic factors, processing of cytokines, growth factors and growth factor receptors, and the production of endogenous inhibitors.

Urinary matrix metalloproteinases and their endogenous inhibitors predict hepatic regeneration after murine partial hepatectomy.

BACKGROUND: Matrix metalloproteinases (MMPs) play a key role in extracellular matrix remodeling events associated with hepatic regeneration after partial hepatectomy. We therefore hypothesized that urinary MMPs and their endogenous tissue inhibitors of matrix metalloproteinases (TIMPs) might also provide important information regarding initiation and progression of liver regeneration. METHODS: Groups of 20 mice underwent sham operations, two-thirds hepatectomy, or treatment with the angiogenesis inhibitor, AGM-1470,O-chloroacetyl-carbamoyl-fumagillol (TNP-470), after two-thirds hepatectomy to prevent hepatic regeneration. Urine was collected preoperatively and for 24 days after surgery and tested for MMP-2, MMP-9, TIMP-1, and TIMP-2 using substrate gel electrophoresis (zymography) and Western blot analysis. RESULTS: During hepatic regeneration, MMP-9 was detected in the urine at significantly lower levels on postoperative day 8 when the liver returned to its preoperative mass. In contrast, urine from mice whose livers were inhibited from regenerating (TNP-treated groups) contained increased levels of the gelatinases MMP-2 and MMP-9. The MMP inhibitors, TIMP-1 and TIMP-2, were significantly reduced in the urine of mice with normally regenerating livers but were increased in the urine of mice treated with TNP-470 on day 8. CONCLUSIONS: We demonstrate that (1) urinary MMPs and their cognate inhibitors, the TIMPs, can be detected in the urine of mice undergoing partial hepatectomy, (2) the presence of these remodeling proteins in the urine may predict the progressive return of the partially resected liver to its preoperative mass, and (3) analysis of urinary MMPs and TIMPs may someday provide a noninvasive means of monitoring the status of patients undergoing hepatic resection and transplantation.