MT1-MMP and MMP-2 mRNA expression in human ovarian tumors: possible implications for the role of desmoplastic fibroblasts

Utility of Matrix Metalloproteinases in the Diagnosis, Monitoring and Prognosis of Ovarian Cancer Patients

Ovarian cancer is one of the most common gynecologic malignancies. It is characterized by a high mortality rate, which is mainly due to the asymptomatic course of the disease. In light of the high mortality rate and increasing morbidity, new diagnostic methods are being explored to enable earlier detection, better monitoring, and improved prognosis. Such diagnostic methods include the assessment of tumor markers in various biological samples. Among the markers currently being investigated, extracellular matrix metalloproteinases (MMPs) are of particular interest. The objective of this article was to compile the existing knowledge of MMPs in ovarian cancer patients and to describe their potential diagnostic utility. Additionally, this article provides an overview of the symptoms, complications, and risk factors associated with ovarian cancer and the role of MMPs in physiology and pathology. Preliminary results indicate that tissue expression and blood and body fluid levels of MMPs may be different in ovarian cancer patients than in healthy women. The expression and concentration of individual MMPs have been shown to be correlated with cancer stage and disease severity. In addition, the preliminary value of some of these enzymes in predicting prognosis is discussed. However, as the amount of data is limited, more studies are needed to fully evaluate the potential function of individual MMPs in ovarian cancer patients. Based on the knowledge gathered for this article, it seems that MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-13, are tentatively the most useful. A thorough evaluation of their utility as modern biomarkers in ovarian cancer requires further investigation.

The role of MMP-14 in ovarian cancer: a systematic review

AIM

In order to evaluate the role of MMP-14 in ovarian cancer, a systematic review was conducted.

METHODS

In March 2020, a search in Pubmed was performed with MMP-14 and ovarian cancer as search terms. After exclusion of the references not on MMP-14 or ovarian cancer or not in English, the studies found were classified into two categories: basic research and clinicopathological research.

RESULTS

In total, 94 references were found of which 33 were excluded. Two additional articles were found in the reference lists of the included studies. Based on the full texts, another 4 were excluded. Eventually, 59 studies were included in the review, 32 on basic research and 19 on clinicopathological research. 8 studies fell in both categories. The basic research studies show that MMP-14 plays an important role in ovarian cancer in the processes of proliferation, invasion, angiogenesis and metastasis. In clinocopathological research, MMP-14 expression is found in most tumours with characteristics of poor prognosis but this immunohistochemical MMP-14 determination does not seem to be an independent predictor of prognosis.

CONCLUSIONS

From this systematic review of the literature concerning MMP-14 in ovarian cancer it becomes clear that MMP-14 plays various important roles in the pathophysiology of ovarian cancer. The exact translation of these roles in the pathophysiology to the importance of MMP-14 in clinicopathological research in ovarian cancer and possible therapeutic role of anti-MMP-14 agents needs further elucidation.

p85β regulates autophagic degradation of AXL to activate oncogenic signaling

PIK3R2 encodes the p85β regulatory subunit of phosphatidylinositol 3-kinase and is frequently amplified in cancers. The signaling mechanism and therapeutic implication of p85β are poorly understood. Here we report that p85β upregulates the protein level of the receptor tyrosine kinase AXL to induce oncogenic signaling in ovarian cancer. p85β activates p110 activity and AKT-independent PDK1/SGK3 signaling to promote tumorigenic phenotypes, which are all abolished upon inhibition of AXL. At the molecular level, p85β alters the phosphorylation of TRIM2 (an E3 ligase) and optineurin (an autophagy receptor), which mediate the selective regulation of AXL by p85β, thereby disrupting the autophagic degradation of the AXL protein. Therapeutically, p85β expression renders ovarian cancer cells vulnerable to inhibitors of AXL, p110, or PDK1. Conversely, p85β-depleted cells are less sensitive to these inhibitors. Together, our findings provide a rationale for pharmacological blockade of the AXL signaling axis in PIK3R2-amplified ovarian cancer.

Surgical margins in head and neck cancer: Intra- and postoperative considerations

OBJECTIVE

To provide a perspective on the significance of recent reports for optimizing cancer free surgical margins that have challenged standard practices.

METHODS

We conducted a review of the recent literature (2012-2018) using the keywords surgical margin analysis, frozen and paraffin section techniques, head and neck cancer, spectroscopy and molecular markers.

RESULTS

Of significance are the reports indicating superiority of tumor specimen directed sampling of margins compared to patient directed (tumor bed) sampling for frozen section control of oral cancers. With reference to optimal distance between tumor and the surgical margin, recent reports recommended cutoffs less than 5mm. Employment of new technologies such as light spectroscopy and molecular analysis of tissues, provide opportunities for a "real time" assessment of surgical margins.

CONCLUSIONS

The commonly practiced method of patient directed margin sampling involving previous studies raises concern over conclusions made regarding the efficacy of frozen section margin control. The recent studies that challenge the optimal distance for clear surgical margins are retrospective and address patient cohorts with inherently confounding factors. The use of novel ancillary techniques require further refinements, clinical trial validation, and justification based on the additional resources.

CD133 Promotes Adhesion to the Ovarian Cancer Metastatic Niche

Cancer stem cells (CSCs) are an attractive therapeutic target due to their predicted role in both metastasis and chemoresistance. One of the most commonly agreed on markers for ovarian CSCs is the cell surface protein CD133. CD133+ ovarian CSCs have increased tumorigenicity, resistance to chemotherapy, and increased metastasis. Therefore, we were interested in defining how CD133 is regulated and whether it has a role in tumor metastasis. Previously we found that overexpression of the transcription factor, ARID3B, increased the expression of PROM1 (CD133 gene) in ovarian cancer cells in vitro and in xenograft tumors. We report that ARID3B directly regulates PROM1 expression. Importantly, in a xenograft mouse model of ovarian cancer, knockdown of PROM1 in cells expressing exogenous ARID3B resulted in increased survival time compared with cells expressing ARID3B and a control short hairpin RNA. This indicated that ARID3B regulation of PROM1 is critical for tumor growth. Moreover, we hypothesized that CD133 may affect metastatic spread. Given that the peritoneal mesothelium is a major site of ovarian cancer metastasis, we explored the role of PROM1 in mesothelial attachment. PROM1 expression increased adhesion to mesothelium in vitro and ex vivo. Collectively, our work demonstrates that ARID3B regulates PROM1 adhesion to the ovarian cancer metastatic niche.

MMP Inhibitors: Experimental and Clinical Studies

Matrix metalloproteases (MMPs) are a family of structurally related enzymes that are capable of degrading proteins of the extracellular matrix. These enzymes play a role in tissue remodelling associated with both physiological and pathogenic processes. A high expression of MMPs is associated with cancer malignancy: it is related to the tumor's ability to metastasize and to the process of angiogenesis. Treatment with MMP inhibitors alone or in combination with cytotoxic therapy is an interesting novel approach to control tumor progression. The expected mechanism of action of these compounds and the difference in side effects compared to cytotoxic drugs make the definition of endpoints and the assessment of response difficult. Furthermore, it is not yet clear whether tumor vascularization or, more specifically, MMP expression/activation should be a criterion of eligibility for this kind of treatment. This review provides an overview of the characteristics of MMPs and their role in tumor progression, metastasis and angiogenesis. Preclinical and clinical studies with synthetic MMP inhibitors are described. The presence of MMPs in biological fluids of patients and their use in prognostic evaluation and in determining the efficacy of treatment with MMP inhibitors is discussed.

Integrin-linked kinase activity modulates the pro-metastatic behavior of ovarian cancer cells

Epithelial ovarian cancer (EOC) is the most fatal gynecologic cancer in the U.S., resulting in >14,000 deaths/year. Most women are diagnosed at late stage with widely disseminated intra-peritoneal metastatic disease, resulting in a 5-year survival rate of <30%. EOCs spread via direct extension and exfoliation into the peritoneal cavity, adhesion to peritoneal mesothelial cells, mesothelial cell retraction to expose sub-mseothelial matrix and anchoring in the type I collagen-rich matrix to generate secondary lesions. As a molecular-level understanding of EOC metastasis may identify novel therapeutic targets, the current study evaluated the expression and activity of integrin-linked kinase (ILK), a Ser/Thr protein kinase activated upon integrin-mediated adhesion. Results show that ILK is co-expressed in EOC with the pro-metastatic enzyme membrane type 1 matrix metalloproteinase (MT1-MMP) and catalyzed phosphorylation of the cytoplasmic tail of the proteinase. Downregulation of ILK expression or activity reduced adhesion to and invasion of collagen gels and organotypic meso-mimetic cultures. As an initial early event in EOC metastasis is integrin-mediated adhesion, these results suggest that further evaluation of ILK inhibitors as anti-metastatic agents in EOC is warranted.

Complex Determinants of Epithelial: Mesenchymal Phenotypic Plasticity in Ovarian Cancer

Unlike most epithelial malignancies which metastasize hematogenously, metastasis of epithelial ovarian cancer (EOC) occurs primarily via transcoelomic dissemination, characterized by exfoliation of cells from the primary tumor, avoidance of detachment-induced cell death (anoikis), movement throughout the peritoneal cavity as individual cells and multi-cellular aggregates (MCAs), adhesion to and disruption of the mesothelial lining of the peritoneum, and submesothelial matrix anchoring and proliferation to generate widely disseminated metastases. This exceptional microenvironment is highly permissive for phenotypic plasticity, enabling mesenchymal-to-epithelial (MET) and epithelial-to-mesenchymal (EMT) transitions. In this review, we summarize current knowledge on EOC heterogeneity in an EMT context, outline major regulators of EMT in ovarian cancer, address controversies in EMT and EOC chemoresistance, and highlight computational modeling approaches toward understanding EMT/MET in EOC.

Cadherin composition and multicellular aggregate invasion in organotypic models of epithelial ovarian cancer intraperitoneal metastasis

During epithelial ovarian cancer (EOC) progression, intraperitoneally disseminating tumor cells and multi-cellular aggregates (MCAs) present in ascites fluid adhere to the peritoneum and induce retraction of the peritoneal mesothelial monolayer prior to invasion of the collagen-rich sub-mesothelial matrix and proliferation into macro-metastases. Clinical studies have shown heterogeneity among EOC metastatic units with respect to cadherin expression profiles and invasive behavior, however the impact of distinct cadherin profiles on peritoneal anchoring of metastatic lesions remains poorly understood. In the current study, we demonstrate that metastasis-associated behaviors of ovarian cancer cells and MCAs are influenced by cellular cadherin composition. Our results show that mesenchymal N-cadherin expressing (Ncad+) cells and MCAs invade much more efficiently than E-cadherin expressing (Ecad+) cells. Ncad+ MCAs exhibit rapid lateral dispersal prior to penetration of three-dimensional collagen matrices. When seeded as individual cells, lateral migration and cell-cell junction formation precede matrix invasion. Neutralizing the Ncad extracellular domain with the monoclonal antibody GC-4 suppresses lateral dispersal and cell penetration of collagen gels. In contrast, use of a broad spectrum matrix metalloproteinase (MMP) inhibitor (GM6001) to block endogenous membrane type 1 matrix metalloproteinase (MT1-MMP) activity does not fully inhibit cell invasion. Using intact tissue explants, Ncad+ MCAs were also shown to efficiently rupture peritoneal mesothelial cells, exposing the sub-mesothelial collagen matrix. Acquisition of Ncad by E-cadherin expressing cells (Ecad+) increased mesothelial clearance activity, but was not sufficient to induce matrix invasion. Furthermore, co-culture of Ncad+ with Ecad+ cells did not promote a “leader-follower” mode of collective cell invasion, demonstrating that matrix remodeling and creation of invasive micro-tracks are not sufficient for cell penetration of collagen matrices in the absence of Ncad. Collectively, our data emphasize the role of Ncad in intraperitoneal seeding of EOC and provide the rationale for future studies targeting Ncad+ in pre-clinical models of EOC metastasis.

Development of a Novel PET Tracer [18F]AlF-NOTA-C6 Targeting MMP2 for Tumor Imaging

Background and Objective

The overexpression of gelatinases, that is, matrix metalloproteinase MMP2 and MMP9, has been associated with tumor progression, invasion, and metastasis. To image MMP2 in tumors, we developed a novel ligand termed [¹⁸F]AlF-NOTA-C6, with consideration that: c(KAHWGFTLD)NH₂ (herein, C6) is a selective gelatinase inhibitor; Cy5.5-C6 has been visualized in many in vivo tumor models; positron emission tomography (PET) has a higher detection sensitivity and a wider field of view than optical imaging; fluorine-18 (¹⁸F) is the optimal PET radioisotope, and the creation of a [¹⁸F]AlF-peptide complex is a simple procedure.

Methods

C6 was conjugated to the bifunctional chelator NOTA (1, 4, 7-triazacyclononanetriacetic acid) for radiolabeling [¹⁸F]AlF conjugation. The MMP2-binding characteristics and tumor-targeting efficacy of [¹⁸F]AlF-NOTA-C6 were tested in vitro and in vivo.

Results

The non-decay corrected yield of [¹⁸F]AlF-NOTA-C6 was 46.2–64.2%, and the radiochemical purity exceeded 95%. [¹⁸F]AlF-NOTA-C6 was favorably retained in SKOV3 and PC3 cells, determined by cell uptake. Using NOTA-C6 as a competitive ligand, the uptake of [¹⁸F]AlF-NOTA-C6 in SKOV3 cells decreased in a dose-dependent manner. In biodistribution and PET imaging studies, higher radioactivity concentrations were observed in tumors. Pre-injection of C6 caused a marked reduction in tumor tissue uptake. Immunohistochemistry showed MMP2 in tumor tissues.

Conclusions

[¹⁸F]AlF-NOTA-C6 was easy to synthesize and has substantial potential as an imaging agent that targets MMP2 in tumors.

Targeting of MMP2 activity in malignant tumors with a 68Ga-labeled gelatinase inhibitor cyclic peptide

INTRODUCTION

Elevated levels of gelatinases (matrix metalloproteinases 2/9, i.e., MMP2 and MMP9) are associated with tumor progression, invasion and metastasis, so these enzymes are potential targets for tumor imaging. The peptide c(KAHWGFTLD)NH2 (herein, C6) is a selective gelatinase inhibitor. Cy5.5-C6 has been visualized in many tumor models in vivo. However, the sensitivity and penetrance of optical imaging are poor. It is well known that positron emission tomography (PET) has a high detection sensitivity and Gallium-68 ((68)Ga) is an optimal PET radioisotope. Thus, in the present study, we developed a novel ligand, (68)Ga-NOTA-C6, to image MMP2 activity in tumors.

METHODS

C6 was conjugated with the bifunctional chelator NOTA (1,4,7-triazacyclononanetriacetic acid) and labeled with (68)Ga. In vitro uptake and binding analyses were performed by using SKOV3 cell lines, coincubating with or without the MMP inhibitor doxycycline. The biodistribution and PET imaging were conducted on SKOV3 ovarian tumor models. MMP2 expression in tumors was analyzed by immunohistochemistry (IHC).

RESULTS

The non-decay corrected yield of (68)Ga-NOTA-C6 was 61.8%-63.3%. (68)Ga-NOTA-C6 was stable in both physiological saline and human serum. The uptake of (68)Ga-NOTA-C6 in SKOV3 cells increased with time, and could be blocked by doxycycline in a dose dependent manner. The results of biodistribution and PET imaging showed that high radioactivity concentrations of (68)Ga-NOTA-C6 occurred in tumors. The ratios of tumor to blood, muscle and ovary and oviduct at 30, 60 and 120min p.i. were 2.78±0.54, 3.86±0.65, 0.48±0.14, and 1.73±0.36, 10.31±3.12, 1.22±0.10, and 2.50±0.78, 7.03±1.85, 0.97±0.25, respectively. The tracer was excreted mainly through the renal system, as evidenced by high levels of radioactivity in the kidneys. These data support the possibility of using (68)Ga-NOTA-C6 in PET to visualize tumors that overexpress MMP2.

CONCLUSIONS

(68)Ga-NOTA-C6 is a potential radiopharmaceutical for the imaging of in vivo MMP2 activity in tumors.

miR-181a-5p Inhibits Cancer Cell Migration and Angiogenesis via Downregulation of Matrix Metalloproteinase-14

Upregulation of matrix metalloproteinase MMP-14 (MT1-MMP) is associated with poor prognosis in cancer patients, but it is unclear how MMP-14 becomes elevated in tumors. Here, we show that miR-181a-5p is downregulated in aggressive human breast and colon cancers where its levels correlate inversely with MMP-14 expression. In clinical specimens, enhanced expression of MMP-14 was observed in cancer cells located at the invasive front of tumors where miR-181a-5p was downregulated relative to adjacent normal cells. Bioinformatics analyses defined a potential miR-181a-5p response element within the 3'-untranslated region of MMP-14 that was validated in reporter gene experiments. Ectopic miR-181a-5p reduced MMP-14 expression, whereas miR-181a-5p attenuation elevated MMP-14 expression. In support of a critical relationship between these two genes, miR-181a-5p-mediated reduction of MMP-14 levels was sufficient to decrease cancer cell migration, invasion, and activation of pro-MMP-2. Furthermore, this reduction in MMP-14 levels was sufficient to reduce in vivo invasion and angiogenesis in chick chorioallantoic membrane assays. Taken together, our results establish the regulation of MMP-14 in cancers by miR-181a-5p through a posttranscriptional mechanism, and they further suggest strategies to elevate miR-181a-5p to prevent cancer metastasis.

Visual and automated assessment of matrix metalloproteinase-14 tissue expression for the evaluation of ovarian cancer prognosis

The purpose of this study was to evaluate whether the membrane type 1 matrix metalloproteinase-14 (or MT1-MMP) tissue expression, as assessed visually on digital slides and by digital image analysis, could predict outcomes in women with ovarian carcinoma. Tissue microarrays from a cohort of 211 ovarian carcinoma women who underwent a debulking surgery between 1993 and 2006 at the CHU de Québec (Canada) were immunostained for matrix metalloproteinase-14. The percentage of MMP-14 staining was assessed visually and with the Calopix software. Progression was evaluated using the CA-125 and/or the RECIST criteria according to the GCIG criteria. Dates of death were obtained by record linkage with the Québec mortality files. Adjusted hazard ratios of death and progression with their 95% confidence intervals were estimated using the Cox model. Comparisons between the two modalities of MMP-14 assessment were done using the box plots and the Kruskal-Wallis test. The highest levels of MMP-14 immunostaining were associated with nonserous histology, early FIGO stage, and low preoperative CA-125 levels (P<0.05). In bivariate analyses, the higher level of MMP-14 expression (>40% of MMP-14-positive cells) was inversely associated with progression using visual assessment (hazard ratio=0.39; 95% confidence interval: 0.18-0.82). A similar association was observed with the highest quartile of MMP-14-positive area assessed by digital image analysis (hazard ratio=0.48; 95% confidence interval: 0.28-0.82). After adjustment for standard prognostic factors, these associations were no longer significant in the ovarian carcinoma cohort. However, in women with serous carcinoma, the highest quartile of MMP-14-positive area was associated with progression (adjusted hazard ratio=0.48; 95% confidence interval: 0.24-0.99). There was no association with overall survival. The digital image analysis of MMP-14-positive area matched the visual assessment using three categories (>40% vs 21-40 vs <20%). Higher levels of MMP-14 immunostaining were associated with standard factors of better ovarian carcinoma prognosis. In women with serous carcinoma, high expression of MMP-14 was associated with lower progression.

The role of the tumor stroma in ovarian cancer

The tumor microenvironment, consisting of stromal myofibroblasts, endothelial cells, and leukocytes, is growingly perceived to be a major contributor to the pathogenesis and disease progression in practically all cancer types. Stromal myofibroblasts produce angiogenic factors, proteases, growth factors, immune response-modulating proteins, anti-apoptotic proteins, and signaling molecules, and express surface receptors and respond to stimuli initiated in the tumor cells to establish a bi-directional communication network in the microenvironment to promote tumor cell invasion and metastasis. Many of these molecules are candidates for targeted therapy and the cancer stroma has been recently regarded as target for biological intervention. This review provides an overview of the biology and clinical role of the stroma in ovarian cancer.

Characterizing the Genetic Basis for Nicotine Induced Cancer Development: A Transcriptome Sequencing Study

Nicotine is a known risk factor for cancer development and has been shown to alter gene expression in cells and tissue upon exposure. We used Illumina® Next Generation Sequencing (NGS) technology to gain unbiased biological insight into the transcriptome of normal epithelial cells (MCF-10A) to nicotine exposure. We generated expression data from 54,699 transcripts using triplicates of control and nicotine stressed cells. As a result, we identified 138 differentially expressed transcripts, including 39 uncharacterized genes. Additionally, 173 transcripts that are primarily associated with DNA replication, recombination, and repair showed evidence for alternative splicing. We discovered the greatest nicotine stress response by HPCAL4 (up-regulated by 4.71 fold) and NPAS3 (down-regulated by -2.73 fold); both are genes that have not been previously implicated in nicotine exposure but are linked to cancer. We also discovered significant down-regulation (-2.3 fold) and alternative splicing of NEAT1 (lncRNA) that may have an important, yet undiscovered regulatory role. Gene ontology analysis revealed nicotine exposure influenced genes involved in cellular and metabolic processes. This study reveals previously unknown consequences of nicotine stress on the transcriptome of normal breast epithelial cells and provides insight into the underlying biological influence of nicotine on normal cells, marking the foundation for future studies.

Fibrotic focus and hypoxia in male breast cancer

Fibrotic focus is a scar-like lesion near the center of a carcinoma and has been associated with high-grade, lymph node metastases and poor survival in female breast cancers. Hypoxia is suggested to be the crucial link between fibrotic focus and aggressive tumor phenotype and is also itself a poor prognostic marker. We here set out to study fibrotic focus and hypoxia in male breast cancer for the first time. In a group of 134 male breast cancer patients, the presence and size of a fibrotic focus and the expression of three hypoxia-related immunohistochemical stainings, hypoxia-inducible factor-1α, carbonic anhydrase IX and Glut-1 were studied in correlation with clinicopathological features and prognosis. Fibrotic focus was seen in 25% of the male breast cancer cases and was correlated with hypoxia-inducible factor-1α overexpression (P=0.023), high grade (P=0.005), high mitotic activity (P=0.005) and lymph node metastases (P=0.037). Hypoxia-inducible factor-1α-positive tumors were more often high grade (P=0.003) and HER2 amplified (P=0.005). Glut-1 expression was also more common in grade 3 tumors (P=0.038), but no association between carbonic anhydrase IX and any clinicopathological feature was found. Fibrotic focus >8 mm and hypoxia-inducible factor-1α overexpression were correlated with decreased patients' outcome (P=0.035 and 0.008, respectively). Hypoxia-inducible factor-1α overexpression was an independent and the most powerful predictor of survival in multivariate analysis (P=0.029; hazard ratio 2.5). In conclusion, the presence of a fibrotic focus is associated with hypoxia-inducible factor-1α overexpression, and both are associated with aggressive tumor phenotype and poor survival in male breast cancer. These markers seem to have similar clinical importance as previously reported in female breast cancer.

Expression of MMP-2, -7, -9, MT1-MMP and TIMP-1 and -2 has no prognostic relevance in patients with advanced epithelial ovarian cancer

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in tumor invasion, but their prognostic significance is still under discussion. We set out to analyze the epithelial and stromal expression of MMP-2, MMP-7, MMP-9, MT1-MMP, TIMP-1 and TIMP-2 in advanced epithelial ovarian cancers and to assess their prognostic value. A tissue microarray of malignant ovarian tumors from 69 patients was constructed. Immunostaining results were scored using the HSCORE and assessed by univariate analysis with Bonferroni correction and classical multidimensional scaling (CMDS). Kaplan-Meier survival curves calculated with regard to patient and tumor characteristics were compared by the log-rank test. Patients treated by primary surgery (n=43) had a higher tumor size and a trend toward higher epithelial MMP and TIMP expression than those treated by interval surgery (n=26). Optimal cytoreduction (residue ≤ 1 cm) was obtained in 27 and 18 patients, respectively. Clinical and histological characteristics were not different in patients with optimal cytoreduction and those with suboptimal cytoreduction. The expression of epithelial MMP-9 (P=0.002) and TIMP-2 (P=0.026) were higher in the latter group. CMDS failed to demonstrate any influence of MMP and TIMP expression with regard to cytoreduction outcome. MMP and TIMP expression did not influence survival. Their prognostic values were outweighed by histological type, lymph node involvement and cytoreduction. Standard statistical analysis adjusted after Bonferroni correction and CMDS reduced the relevance of MMPs and TIMPs in the prognosis of patients with advanced ovarian cancer.

Gonadotropin-releasing hormone-II increases membrane type I metalloproteinase production via beta-catenin signaling in ovarian cancer cells

GnRH-II is produced by ovarian cancer cells and enhances their invasiveness in vitro. In our studies of OVCAR-3 and CaOV-3 ovarian cancer cell lines, GnRH-II treatment induced phosphorylation of Akt and glycogen synthase kinase (GSK)3β, as well as β-catenin accumulation in the nucleus, and the latter was reduced by small interfering RNA (siRNA)-mediated depletion of the GnRH receptor. The phosphatidylinositol 3 kinase (PI3K)/Akt pathway is involved in β-catenin-dependent signaling, and pretreatment of these human ovarian cancer cells with a PI3K/Akt inhibitor, LY294002, attenuated GnRH-II-stimulated phosphorylation of GSK3β and inhibited GnRH-II-induced invasion. It also attenuated GnRH-II induced trans-activation of a β-catenin-dependent reporter gene, most likely because GSK3β phosphorylation promotes translocation of β-catenin to the nucleus. Membrane type I matrix metalloproteinase (MT1-MMP) contributes to tumor progression directly, or by processing the latent MMP-2 zymogen, and is a known target of β-catenin signaling. When OVCAR-3 and CaOV-3 cells were treated with GnRH-II, MT1-MMP levels increased approximately 3-fold, whereas siRNA-mediated depletion of GnRH receptor or pretreatment with LY294002 abrogated this. In addition, lithium chloride, which increases GSK3β phosphorylation and the nuclear translocation of β-catenin, increased MT1-MMP levels in these ovarian cancer cells. By contrast, depletion of β-catenin by siRNA treatment abolished GnRH-II-induced MT1-MMP synthesis and reduced their invasive potential. Furthermore, siRNA-mediated reduction of MT1-MMP levels reduced GnRH-II-induced invasion in ovarian cancer cells. We therefore conclude that GnRH-II stimulates the PI3K/Akt pathway, and the phosphorylation of GSK3β, thereby enhancing the β-catenin-dependent up-regulation of MT1-MMP production, which contributes to ovarian cancer metastasis.

Overexpression of proto-oncogene FBI-1 activates membrane type 1-matrix metalloproteinase in association with adverse outcome in ovarian cancers

Background

FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) is a member of the POK (POZ and Kruppel) family of transcription factors and play important roles in cellular differentiation and oncogenesis. Recent evidence suggests that FBI-1 is expressed at high levels in a subset of human lymphomas and some epithelial solid tumors. However, the function of FBI-1 in human ovarian cancers remains elusive.

Results

In this study, we investigated the role of FBI-1 in human ovarian cancers, in particularly, its function in cancer cell invasion via modulating membrane type 1-matrix metalloproteinase (MT1-MMP). Significantly higher FBI-1 protein and mRNA expression levels were demonstrated in ovarian cancers samples and cell lines compared with borderline tumors and benign cystadenomas. Increased FBI-1 mRNA expression was correlated significantly with gene amplification (P = 0.037). Moreover, higher FBI-1 expression was found in metastatic foci (P = 0.036) and malignant ascites (P = 0.021), and was significantly associated with advanced stage (P = 0.012), shorter overall survival (P = 0.032) and disease-free survival (P = 0.016). In vitro, overexpressed FBI-1 significantly enhanced cell migration and invasion both in OVCA 420 and SKOV-3 ovarian carcinoma cells, irrespective of p53 status, accompanied with elevated expression of MT1-MMP, but not MMP-2 or TIMP-2. Moreover, knockdown of MT1-MMP abolished FBI-1-mediated cell migration and invasion. Conversely, stable knockdown of FBI-1 remarkably reduced the motility of these cells with decreased expression of MT1-MMP. Promoter assay and chromatin immunoprecipitation study indicated that FBI-1 could directly interact with the promoter spanning ~600bp of the 5'-flanking sequence of MT1-MMP and enhanced its expression in a dose-dependent manner. Furthermore, stable knockdown and ectopic expression of FBI-1 decreased and increased cell proliferation respectively in OVCA 420, but not in the p53 null SKOV-3 cells.

Conclusions

Our results suggested an important role of FBI-1 in ovarian cancer cell proliferation, cell mobility, and invasiveness, and that FBI-1 can be a potential target of chemotherapy.

Ovarian cancer cell detachment and multicellular aggregate formation are regulated by membrane type 1 matrix metalloproteinase: a potential role in I.p. metastatic dissemination

An early event in the metastasis of epithelial ovarian carcinoma is shedding of cells from the primary tumor into the peritoneal cavity followed by diffuse i.p. seeding of secondary lesions. Anchorage-independent metastatic cells are present as both single cells and multicellular aggregates (MCA), the latter of which adhere to and disaggregate on human mesothelial cell monolayers, subsequently forming invasive foci. Although this unique metastatic mechanism presents a distinct set of therapeutic challenges, factors that regulate MCA formation and dissemination have not been extensively evaluated. Proteolytic activity is important at multiple stages in i.p. metastasis, catalyzing migration through the mesothelial monolayer and invasion of the collagen-rich submesothelial matrix to anchor secondary lesions, and acquisition of membrane type 1 matrix metalloproteinase (MT1-MMP; MMP-14) expression promotes a collagen-invasive phenotype in ovarian carcinoma. MT1-MMP is regulated posttranslationally through multiple mechanisms including phosphorylation of its cytoplasmic tail, and the current data using ovarian cancer cells expressing wild-type, phosphomimetic (T567E-MT1-MMP), and phosphodefective (T567A-MT1-MMP) MT1-MMP show that MT1-MMP promotes MCA formation. Confluent T567E-MT1-MMP-expressing cells exhibit rapid detachment kinetics, spontaneous release as cell-cell adherent sheets concomitant with MT1-MMP-catalyzed alpha(3) integrin ectodomain shedding, and robust MCA formation. Expansive growth within three-dimensional collagen gels is also MT1-MMP dependent, with T567E-MT1-MMP-expressing cells exhibiting multiple collagen invasive foci. Analysis of human ovarian tumors shows elevated MT1-MMP in metastases relative to paired primary tumors. These data suggest that MT1-MMP activity may be key to ovarian carcinoma metastatic success by promoting both formation and dissemination of MCAs.

EGF-receptor regulation of matrix metalloproteinases in epithelial ovarian carcinoma

Ovarian carcinoma is most frequently detected when disease has already disseminated intra-abdominally, resulting in a 5-year survival rate of less than 20% owing to complications of metastasis. Peritoneal ascites is often present, establishing a unique microenvironmental niche comprised of tumor and inflammatory cells, along with a wide range of bioactive soluble factors, several of which stimulate the EGF-receptor (EGFR). Elevated EGFR is associated with less favorable disease outcome in ovarian cancer, related in part to EGFR activation of signaling cascades that lead to enhanced matrix metalloproteinase expression and/or function. The available data suggest that modulating the expression or activity of the EGFR and/or matrix metalloproteinases offers opportunity for targeted intervention in patients with metastatic disease.

Activity of 2 methoxyestradiol (Panzem NCD) in advanced, platinum-resistant ovarian cancer and primary peritoneal carcinomatosis: a Hoosier Oncology Group trial

BACKGROUND

2-Methoxyestradiol (Panzem, 2ME2) is an endogenous metabolite of estradiol that destabilizes microtubules and exerts anti-angiogenic properties. This study was conducted to determine the activity and safety of 2ME2 administered as a NanoCrystal dispersion (NCD) formulation in patients with recurrent, platinum-resistant epithelial ovarian cancer (EOC).

METHODS

Eligible patients had relapsed, platinum-resistant or refractory EOC with measurable or detectable disease. There was no limit on the number of prior treatment regimens. 2ME2 NCD 1000 mg orally four times daily (q.i.d.) was administered continuously during 4 week cycles. The primary endpoint was objective response rate (ORR). Secondary endpoints were assessment of toxicity, rate of clinical benefit defined as the number of patients experiencing an objective response, a CA125 response or stable disease (SD) >3 months, mean change in CA-125, progression-free survival (PFS), and pharmacokinetic analyses of 2ME2.

RESULTS

Eighteen patients were enrolled. Median age was 65.5 (range 40-73). Patients had received a median of five prior treatments. The most common adverse events were fatigue (78%), nausea (78%), diarrhea (39%), neuropathy (50%), edema (39%), and dyspnea (44%), the majority being grade 1-2. There were no objective responses, but seven patients had SD as best response. Of those, two patients had SD for greater than 12 months. The rate of clinical benefit was 31.3%. Fairly stable plasma levels of 2ME2 ranging within the predicted therapeutic window were observed.

CONCLUSIONS

The NCD formulation of 2ME2 is well tolerated in patients with heavily pretreated EOC. Few of these heavily pretreated patients had sustained stable disease.

Epidermal growth factor receptor-mediated membrane type 1 matrix metalloproteinase endocytosis regulates the transition between invasive versus expansive growth of ovarian carcinoma cells in three-dimensional collagen

The epidermal growth factor receptor (EGFR) is overexpressed in ovarian carcinomas and promotes cellular responses that contribute to ovarian cancer pathobiology. In addition to modulation of mitogenic and motogenic behavior, emerging data identify EGFR activation as a novel mechanism for rapid modification of the cell surface proteome. The transmembrane collagenase membrane type 1 matrix metalloproteinase (MT1-MMP, MMP-14) is a major contributor to pericelluar proteolysis in the ovarian carcinoma microenvironment and is subjected to extensive posttranslational regulation. In the present study, the contribution of EGFR activation to control of MT1-MMP cell surface dynamics was investigated. Unstimulated ovarian cancer cells display caveolar colocalization of EGFR and MT1-MMP, whereas EGFR activation prompts internalization via distinct endocytic pathways. EGF treatment results in phosphorylation of the MT1-MMP cytoplasmic tail, and cells expressing a tyrosine mutated form of MT1-MMP (MT1-MMP-Y(573)F) exhibit defective MT1-MMP internalization. As a result of sustained cell surface MT1-MMP activity, a phenotypic epithelial-mesenchymal transition is observed, characterized by enhanced migration and collagen invasion, whereas growth within three-dimensional collagen gels is inhibited. These data support an EGFR-dependent mechanism for regulation of the transition between invasive and expansive growth of ovarian carcinoma cells via modulation of MT1-MMP cell surface dynamics.

Expression of membrane type 1 matrix metalloproteinase (MMP-14) in epithelial ovarian cancer: high level expression in clear cell carcinoma

OBJECTIVE

Clear cell carcinomas of the ovary constitute approximately 5% of all ovarian neoplasms and have a distinct gene expression profile relative to other ovarian carcinoma histotypes. Tumors often present as an early stage large pelvic mass with a high degree of recurrence and frequent early metastasis. Matrix metalloproteinases (MMPs) play a role in intraperitoneal metastasis through breakdown of cell-cell and cell-matrix barriers, enabling anchoring of secondary lesions and promoting proliferation in a geometrically constrained matrix environment. The objective of this study was to evaluate MMP expression in ovarian clear cell carcinoma.

METHODS

Immunohistochemistry was used to evaluate expression of membrane type 1 MMP (MMP-14), MMP-2 and MMP-9 in a panel of ovarian tumors. Western blotting and gelatin zymography were used to examine MMP-14 expression and activity in the clear cell carcinoma cell line ES2. The ability of ES2 cells to invade and proliferate within three-dimensional collagen gels was evaluated.

RESULTS

High level expression of MMP-14 and MMP-2 were observed in ovarian clear cell carcinoma relative to other histotypes (94-95% strong positive). MMP-14 was expressed and active in cultured ES2 cells. ES2 cells also exhibited MMP-dependent invasion of and proliferation within three-dimensional collagen gels.

CONCLUSIONS

The high level expression of MMP-14 together with in vitro functional analyses suggest that MMP-14 may contribute to both the proliferative capacity and the enhanced parenchymal metastasis of ovarian clear cell carcinoma.

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.

p37 from Mycoplasma hyorhinis promotes cancer cell invasiveness and metastasis through activation of MMP-2 and followed by phosphorylation of EGFR

High Mycoplasma infection in gastric cancer tissues suggests a possible association between Mycoplasma infection and tumorigenesis. By using human gastric cancer cells AGS and mouse melanoma cells B16F10 stably expressing p37, the major immunogen of Mycoplasma hyorhinis, we found that p37 enhanced cell motility, migration, and invasion in vitro. With experimental metastasis model in C57BL/6 mice, p37 adenovirus-infected B16F10 cells formed more metastasis lesions in the lung. Furthermore, p37 promoted the phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase and the activity of matrix metalloproteinase-2 (MMP-2). Inhibitor of MMPs significantly blocked p37-induced EGFR but has little effect on extracellular signal-regulated kinase phosphorylation, whereas the p37-induced MMP-2 activation was only partially suppressed by inhibitor of MEK1/2 or by inhibitor of EGFR. However, all these inhibitors significantly reduced the p37-induced invasiveness of AGS cells. These results suggest that p37 may stimulate invasion by increasing the activity of MMP-2, thereby inducing EGFR phosphorylation and contributing to tumor metastasis on M. hyorhinis infection. p37 and its regulated molecules could be the potential targets for cancer therapy.

PEA3 is necessary for optimal epidermal growth factor receptor-stimulated matrix metalloproteinase expression and invasion of ovarian tumor cells

Elevated expression of the epidermal growth factor (EGF) receptor (EGFR) is detected in human ovarian tumors and is associated with decreased recurrence-free and overall survival. EGFR activation affects tumor progression in part by promoting tumor invasion through the induction of prometastatic matrix metalloproteinases (MMP). PEA3, an ETS family transcription factor, is elevated in advanced and metastatic ovarian cancer and regulates MMPs in various cell types, therefore, we investigated whether PEA3 is required for the EGFR-dependent induction of MMP mRNA. MMP-9 and MMP-14 mRNA levels were selectively increased in response to EGFR activity in ovarian tumor cells. EGFR activation resulted in nuclear accumulation of PEA3 and direct binding of PEA3, but not the related protein ETS-1, to the endogenous MMP-9 and MMP-14 promoters. Furthermore, PEA3 overexpression was sufficient to induce MMP-9 and MMP-14 mRNA, tumor cell migration, and invasion, suggesting that PEA3 is an important contributor to the metastatic phenotype. Additionally, inhibition of PEA3 expression via short interfering RNA reduced the EGF induction of MMP-9 and MMP-14 gene expression by 92% and 50%, respectively, and impaired EGF-stimulated tumor cell invasion. These results suggest that PEA3 is regulated by EGFR and that the elevated PEA3 expression detected in human ovarian cancer may divert cells to a more invasive phenotype by regulating MMP-9 and MMP-14.

Influence of genistein isoflavone on matrix metalloproteinase-2 expression in prostate cancer cells

We investigated the expression of matrix metalloproteinase (MMP)-2 in human LNCaP and PC3 prostate cancer cell lines in response to genistein exposure. Initially we studied the phytosensitivity of the cells to genistein using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to determine percentage cell viability/inhibition and the terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end-labeling apoptosis assay to assess the type of cell death. The results revealed that genistein inhibited growth and proliferation in both PC3 (hormone-dependent) and LNCaP (hormone-independent) prostate cancer cell lines, that there was no significant difference in sensitivity to genistein between PC3 and LNCaP cells, and that the effect of genistein on the cells was dose- and time-dependent. The results also revealed that inhibition of cell growth in both PC3 and LNCaP cells was predominantly due to apoptotic cell death. These results were consistent with data in previous studies. This was followed by determination of the MMP-2 profile in response to genistein treatment. The results indicated a significant dose- and time-dependent inhibition of MMP-2 expression levels in both cells, with a highly significant negative correlation between MMP-2 levels and concentration of genistein. This is of phytotherapeutic significance in view of the pivotal role of MMP-2 expression in the pathogenesis of prostate cancer. Increasing expression of MMPs has been identified in many human cancers, including prostate cancer. Our findings indicate that genistein could be a potent therapeutic inhibitor of MMP-2 in line with current concepts of targeted treatment.

Microenvironmental Regulation of Membrane Type 1 Matrix Metalloproteinase Activity in Ovarian Carcinoma Cells via Collagen-induced EGR1 Expression

Late stage ovarian cancer is characterized by disseminated intraperitoneal metastasis as secondary lesions anchor in the type I and III collagen-rich submesothelial matrix. Ovarian carcinoma cells preferentially adhere to interstitial collagen, and collagen-induced integrin clustering up-regulates the expression of the transmembrane collagenase membrane type 1 matrix metalloproteinase (MT1-MMP). Collagenolytic activity is important in intraperitoneal metastasis, potentiating invasion through the mesothelial cell layer and colonization of the submesothelial collagen-rich matrix. The objective of this study was to elucidate a potential mechanistic link between collagen adhesion and MT1-MMP expression. Our results indicate that culturing cells on three-dimensional collagen gels, but not thin layer collagen or synthetic three-dimensional hydrogels, results in rapid induction of the transcription factor EGR1. Integrin signaling through a SRC kinase-dependent pathway is necessary for EGR1 induction. Silencing of EGR1 expression using small interfering RNA abrogated collagen-induced MT1-MMP expression and inhibited cellular invasion of three-dimensional collagen gels. These data support a model for intraperitoneal metastasis wherein collagen adhesion and clustering of collagen binding integrins activates integrin-mediated signaling via SRC kinases to induce expression of EGR1, resulting in transcriptional activation of the MT1-MMP promoter and subsequent MT1-MMP-catalyzed collagen invasion. This model highlights the role of unique interactions between ovarian carcinoma cells and interstitial collagens in the ovarian tumor microenvironment in inducing gene expression changes that potentiate intraperitoneal metastatic progression.

Tissue inhibitor of metalloproteinases-2 improves antitumor efficacy of a replicating adenovirus in vivo

Clinical studies of replicating adenoviruses for the treatment of cancer have demonstrated their safety but have yielded disappointing results, indicating the need for new strategies to improve their efficacy. We hypothesized that the efficacy of a replicating adenovirus could be improved by expression of tissue inhibitor of metalloproteinases-2 (TIMP-2), a 21-kDa unglycosylated secretory protein. TIMP-2 specifically inhibits the active forms of a number of matrix metalloproteinases (MMPs) that play a role in the degradation of basement membranes and the extracellular matrix and are therefore involved in the control of the growth, invasion and metastasis of tumor cells, as well as angiogenesis. In addition, TIMP-2 can abrogate tumor growth and angiogenesis by a variety of mechanisms independent of MMP inhibition. In this study, we demonstrate that expression of TIMP-2 enhanced the antitumor efficacy of a replicating adenovirus in vivo, by reducing both tumor growth and angiogenesis.

The clinical relevance of stromal matrix metalloproteinase expression in ovarian cancer

PURPOSE

Matrix metalloproteinases (MMP) are proteolytic enzymes implicated in cancer progression and metastasis. We sought to determine the role of epithelial (tumor cell-derived) and stromal (host-derived) expression of MMPs in predicting the clinical outcome of patients with epithelial ovarian cancer (EOC).

EXPERIMENTAL DESIGN

MMP-2, MMP-9, and membrane type 1 (MT1)-MMP expression was evaluated using immunohistochemistry in 90 invasive EOCs, and samples were scored for epithelial and stromal staining. Results were correlated with clinicopathologic characteristics using univariate and multivariate analyses.

RESULTS

High expression of MMP-2, MMP-9, and MT1-MMP in tumor epithelium was detected in 54%, 97%, and 100% of cases, and in stromal compartments, in 38%, 70%, and 38% of cases, respectively. High stromal expression of MMP-2, MMP-9, and MT1-MMP was significantly associated with aggressive features such as high stage, high grade ascites, and positive lymph node status. Kaplan-Meier analysis showed that high epithelial and stromal expression of MMP-2, MMP-9, and MT1-MMP were each significantly associated with shorter disease-specific survival (DSS; P < 0.01). On tree-structured survival analysis, patients with strong epithelial MT1-MMP expression had the shortest DSS, whereas patients with moderate epithelial MT1-MMP and low stromal MMP-9 expression had the longest DSS (P < 0.01). On multivariate analysis, high stromal expression of MMP-9 (P = 0.01) and MT1-MMP (P = 0.04), strong epithelial MT1-MMP (P = 0.01) and high stage (P = 0.04) were independent predictors of poor DSS.

CONCLUSIONS

Overexpression of stromal MMP-9 and MT1-MMP is independently associated with shorter DSS in EOC. Thus, host-derived MMPs are valuable predictors of clinical outcome in EOC.

Extracellular matrix metalloprotease inducer stimulates fibroblast-mediated tumor growth in vivo

HYPOTHESIS

Extracellular matrix metalloprotease inducer (EMMPRIN) is a molecule expressed on the cell surface of tumor cells that has been shown to induce both tumor cells and fibroblasts to express matrix metalloproteases in vitro. We hypothesize that fibroblasts are stimulated by EMMPRIN to create a microenvironment favorable to tumor growth.

STUDY DESIGN

Case series review of laryngeal cancer and assessment of tumor cell lines in vivo.

METHODS

EMMPRIN immunoreactivity in 33 pathologic specimens from patients with supraglottic laryngeal cancer was correlated with clinicopathologic features and survival. The CAL 27 cell line was transfected with EMMPRIN (CAL 27E) or a control vector (CAL 27). Cells were xenografted into the flank of severe combined immunodeficient (SCID) mice with or without a co-injection of normal dermal fibroblasts (NDFs).

RESULTS

Immunohistochemical detection of EMMPRIN in laryngeal cancer specimens demonstrated expression in all the tumors but not in adjacent, histologically normal mucosa. EMMPRIN membrane immunoreactivity (transmembrane EMMPRIN score) was associated with nodal positivity (P=.07), and it was associated with poorer survival (hazard ratio=2.4, 95% confidence interval 0.88, 6.55). As a categoric variable, higher EMMPRIN expression positively correlates with higher mortality. To determine whether EMMPRIN mediates tumor growth in vivo through fibroblast stimulation, EMMPRIN-expressing CAL 27 (CAL 27E) xenografted (n=20) onto the flank of SCID mice developed larger tumors than CAL 27 control vector transfected cells alone (n=20), but they were not significantly larger (P=.17). However, when CAL 27E cells were co-injected with NDFs, there was a statistically significant increase in tumor growth compared with the CAL 27 cells co-injected with NDFs (n=10, P=.0038).

CONCLUSIONS

As a cell surface expressed protein that promotes tumor growth and high expression in head and neck squamous cell carcinoma but not in normal tissue, EMMPRIN may be a good target for directed molecular therapy.

Correlation of tumor- and stromal-derived MT1-MMP expression with progression of human ovarian tumors in SCID mice

OBJECTIVE

Human ovarian carcinoma samples were orthotopically implanted into SCID mice to investigate the contribution of matrix metalloproteases (MMPs) to the spread of ovarian tumors.

METHODS

Mice were inoculated with patient tumor samples, and developed ovarian tumors over a 16-week period with metastasis occurring in some mice. Species-specific quantitative RT-PCR was used to identify the source of tumor-associated MMPs.

RESULTS

Membrane-type (MT)1-MMP mRNA was significantly increased in high-grade tumors, tumors with evidence of serosal involvement, and tumors in which distant metastases were detected. The increase in MT1-MMP expression was predominantly from the human tumor cells, with a minor contribution from the mouse ovarian stroma. Neither human nor mouse MT2-MMP were correlated with tumor progression and MT3-MMP levels were negligible. While tumor cells did not produce significant amounts of MMP-2 or MMP-9, the presence of tumor was associated with increased levels of MMP-2 expression by mouse ovarian stroma. Stromal-derived MT1-MMP was greater in large tumors and was associated with stromal MMP-2 expression but neither was significantly linked with metastasis.

CONCLUSIONS

These studies indicate that tumor-derived MT1-MMP, more so than other gelatinolytic MMPs, is strongly linked to aggressive tumor behavior. This orthotopic model of human ovarian carcinoma is appropriate for studying ovarian tumor progression, and will be valuable in the further investigation of the metastatic process.

Histological characteristics of tumor in vessels and lymph nodes are significant predictors of progression of invasive ductal carcinoma of the breast: a prospective study

Invasive ductal carcinomas (IDCs) of the breast are composed of primary invasive tumors as well as tumor cells in blood vessels and lymph nodes. The purpose of this study was to determine whether the histological characteristics of tumor in the vessels and nodes are significantly associated with outcome. In a series of 393 patients, multivariate analyses showed that in IDCs without nodal metastasis and with fibrotic focus dimension, lymph vessel tumor emboli with >6 apoptotic figures and those invading >3 mm from the tumor margin had significantly higher hazard rates (HRs) for recurrence (P<0.05). In IDCs with 1 to 3 nodal metastases, >2 apoptotic figures in tumor emboli in blood vessels and >5 invaded lymph vessels were associated with significantly higher HRs for tumor recurrence and death (P<0.005). In IDCs with 4 or more nodal metastases, nodal tumors with >5 mitotic figures and >5 nodes with extranodal extension were associated with significantly higher HRs for tumor recurrence or death (P<0.05). We conclude that several histological characteristics of tumors in vessels and nodes have significant implications for the progression of IDCs.

Transmembrane proteases in cell growth and invasion: new contributors to angiogenesis?

Transmembrane proteases (TPs) are proteins anchored in the plasma membrane with their catalytic site exposed to the external surface of the membrane. TPs are widely expressed, and their dysregulated expression is associated with cancer, infection, inflammation, autoimmune and cardiovascular diseases, all diseases where angiogenesis is part of the pathology. TPs participate in extracellular proteolysis (degradation of extracellular matrix components, regulation of chemokine activity, release of membrane-anchored cytokines, cytokine receptors and adhesion molecules) and influence cell functions (growth, secretion of angiogenic molecules, motility). Recent attention has been focused on the ADAM-17 (a disintegrin and metalloprotease)/TACE/CD156q, the MT1-MMP (membrane-type-1 matrix metallo proteinase)/MMP-14, and the ectopeptidases aminopeptidase N (APN/CD13), dipeptidyl peptidase IV (DPPIV/CD26) and angiotensin-converting enzyme (ACE/CD143), that appear to have a critical role in angiogenesis. This article summarizes current knowledge on these TPs, and reviews recent investigations that document their participation during angiogenic-related events. Through their multiple roles, TPs may thereby provide critical links in angiogenesis.

Prognostic significance of stromal metalloproteinase-2 in ovarian adenocarcinoma and its relation to carcinoma progression

OBJECTIVES

MMP-2 expression in ovarian cancer cells has been correlated with poor prognosis. This study attempts to assess the prognostic importance of stromal MMP-2 in patients with ovarian endometrioid and serous adenocarcinoma.

METHODS

MMP-2, MMP-2 activator, MT1-MMP, and its inhibitor (TIMP-2) were immunostained in 84 primary epithelial ovarian carcinomas (EOCs) (35 endometrioid adenocarcinomas [ECs] and 49 serous adenocarcinomas [SCs]). Results were correlated to pathological subtypes, tumor stage, grade, size, and to recurrence-free and cancer-specific survival.

RESULTS

MMP-2 and stromal MMP-2 were detected in all carcinoma cells of 22.2% of EC and 77.8% of SC tumors. MT1-MMP co-localized with MMP-2. TIMP-2 staining was weak and cytoplasmically distributed in all tumors. Univariant analysis showed expression of stromal MMP-2 significantly associated with advanced stage (P = 0.018), higher grade (P = 0.005), serous subtype (P = 0.02), smaller tumor size at operation (P = 0.001), and higher incidence of recurrence (P = 0.042), but not with the rate of death due to cancer. By multiple Cox proportional hazard regression analysis, patient survival and disease-free survival were significantly related to the presence of stromal MMP-2 in EC but not SC patients (P < 0.05). However, after multivariant analysis, the associations with patient age, tumor stage, grade, and size no longer existed. In stepwise selection, tumor stage remained the most important predictor of patient survival and disease-free survival in ovarian EC and SC, but stromal MMP-2 remained the most important predictor of recurrence-free survival in patients with EC.

CONCLUSIONS

Stromal MMP-2 occurs early and may play a role early in EOC invasion. Tumor stage and stromal MMP-2 are important predictors of disease-free survival.

Pathophysiological Dynamics of Human Ovarian Surface Epithelial Cells in Epithelial Ovarian Carcinogenesis

Epithelial ovarian cancer is responsible for almost half of all the deaths from female genital tract tumors. Major impediments to the clinical treatment of this disease are the relatively asymptomatic progression and a lack of knowledge regarding defined precursor or malignant lesions. Most epithelial ovarian cancers are thought to arise from the transformation of ovarian surface epithelial cells, a single continuous layer of flat-to-cuboidal mesothelial cells surrounding the ovary. To improve our understanding of the pathogenesis of epithelial ovarian cancer, it is necessary to study the biological characteristics of normal ovarian surface epithelial cells. However, this approach has been hampered by the inability to purify and culture such human cells. During the past decade, procedures to isolate and culture human ovarian surface epithelial cells have been developed, and, subsequently, using viral oncogenes, several immortalized cells have been established. This new experimental system is being employed to improve our understanding of the genetic changes leading to the initiation of epithelial ovarian cancer and to identify events in the cancer's development. This review mainly describes the biological dynamics of ovarian surface epithelial cells in the pathogenesis of epithelial ovarian cancer, focusing on humans and excluding small animal models.

The mouse matrix metalloproteinase, epilysin (MMP-28), is alternatively spliced and processed by a furin-like proprotein convertase

Epilysin (MMP-28) is a recently identified member of the matrix metalloproteinase (MMP) family. To explore the expression of epilysin in vivo and to gain insight into its biological functions, we have cloned the mouse epilysin cDNA and determined its expression. The amino acid sequence of the mouse protein is 85% identical with the human sequence and contains conserved features such as an RKKR furin-activation sequence following the prodomain. Unexpectedly, we found two alternatively spliced forms of the epilysin mRNA lacking 30 and 72 nt at the beginning of the seventh exon coding for part of the haemopexin domain. Expression of recombinant epilysin in HT-1080 fibrosarcoma cells indicated that epilysin was secreted as a major 48 kDa form and a minor 58 kDa form. Expression of the 58 kDa form was increased by a synthetic furin inhibitor at the expense of the 48 kDa form, suggesting that furin cleaves and activates epilysin. Epilysin mRNA was detected in a number of mouse tissues, with the highest expression in the lung, placenta, heart and uterus, and lower levels in the testis and gastrointestinal tract. The wide expression of epilysin in intact, healthy tissues suggests that this MMP functions in physiological tissue homoeostasis and turnover.

Proliferative activities of tumor stromal cells play important roles in tumor thickness and progression of T3 ulcerative-type colorectal cancer

The central depressed area thickness (tumor thickness) of colorectal cancers is an important prognostic parameter for colorectal cancer patients. We examined whether the proliferative activities of tumor and stromal components play important roles in the increase of tumor thickness and the progression of colorectal cancers. Colorectal cancers were classified into thin and thick groups according to tumor thickness. The proliferative activities of fibroblasts and endothelial cells were immunohistochemically evaluated in 157 T3 ulcerative-type colorectal cancers by CD31/MIB-1 (anti-Ki-67 antigen) double staining. The MIB-1 labeling index was estimated as the percentage of fibroblasts with positive nuclei. The CD31-positive microvessels lined by MIB-1-positive endothelial cells were assessed. The proliferative microvessel index was defined as the percentage of proliferative microvessels relative to all microvessels. The fibroblast MIB-1 labeling index was the only parameter significantly associated with tumor thickness ( P=0.049). High fibroblast MIB-1 labeling indices showed significant correlation with tumor recurrence in the thin group ( P=0.020). High proliferative microvessel index was a significant parameter of tumor recurrence in the thick group ( P=0.003) in multivariate analyses. This study strongly suggests that proliferative activities of stromal components are useful parameters of tumor biology and of prognosis for T3 ulcerative-type colorectal cancer patients.

Membrane-type 1 matrix metalloproteinase: a key enzyme for tumor invasion

Matrix metalloproteinases (MMPs) are believed to play a pivotal role in malignant behavior of cancer cells such as rapid tumor growth, invasion, and metastasis by degrading extracellular matrix (ECM). Different types of synthetic inhibitors against MMPs (MMPIs) were developed as candidates for anti-cancer therapeutics and so far clinical trials had led to no significant success. However, this does not diminish the importance of MMPs in the malignancy of cells. Details about MMPs, specifically when and how they take part in the development of cancer are necessary for more advanced application of MMPIs. In this paper, we summarize recent knowledge about membrane-type 1 matrix metalloproteinase (MT1-MMP) which is expressed on cancer cell surface as an invasion-promoting proteinase. By localizing at the leading edge of invasive cancer cells, MT1-MMP degrades components of the tissue barriers. One of the major targets is type I collagen, the most abundant ECM component. Although MT1-MMP itself cannot degrade type IV collagen in the basement membrane, it binds to and activates proMMP-2, one of the type IV collagenases. However, degradation of the ECM is not the sole function of MT1-MMP. MT1-MMP also regulates cell-ECM interaction by processing cell adhesion molecules such as CD44 and integrin alphav chain, and eventually promotes cell migration as well. In addition to the transcriptional regulation, invasion-promoting activity of the MT1-MMP is also strictly monitored at the post-translational level. Precise knowledge about the regulation will give us insight to develop new methods for treating invasive cancer patients.

Advanced pancreatic ductal cancer: fibrotic focus and beta-catenin expression correlate with outcome

INTRODUCTION

Many investigators have examined prognostic factors for advanced pancreatic ductal cancer, but it is still difficult to accurately predict the outcome of the disease.

AIM

To examine correlation between histopathologic factors and outcome of advanced ductal carcinoma of the pancreas.

METHODOLOGY

The subjects were 23 patients who underwent resection of pancreatic ductal cancer classified as stage III according to pTNM classification. Fibrotic focus (which is evidence of intratumoral fibroblast proliferation), tumor size and differentiation, invasion to the portal vein, and immunohistologic expression of E-cadherin and alpha-, beta- andbgr;- and gamma-catenins were evaluated. Correlation between histologic and immunohistologic data and correlation between these data and liver metastasis-free survival and overall survival were assessed by means of the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards regression model (for multivariate analysis).

RESULTS

The presence of fibrotic focus correlated with reduced membranous beta-catenin expression. The presence of fibrotic focus, reduced membranous beta-catenin expression, and reduced cytoplasmic alpha-catenin expression were significantly associated with shorter liver metastasis-free survival. The presence of fibrotic focus also significantly correlated with shorter survival and was the only factor significantly associated with survival in multivariate analysis.

CONCLUSION

The presence of fibrotic focus and reduced beta-catenin expression closely correlated with poor survival of patients with advanced ductal carcinoma of the pancreas.

Identification of membrane-type matrix metalloproteinase-1 as a target of the beta-catenin/Tcf4 complex in human colorectal cancers

Genetic alterations of APC and CTNNB1 (beta-catenin) have been identified in a number of human cancers including tumors arising in the colon and liver. Mutations in these genes lead to abnormal accumulation of beta-catenin and constitutive activation of target genes in the Wnt signaling pathway. To clarify the precise role of accumulated beta-catenin in colorectal carcinogenesis, we searched for genes involved in the beta-catenin/Tcf signaling pathway by cDNA microarray. MT1-MMP (membrane-type matrix metalloproteinase) was among 84 genes that were down-regulated after beta-catenin had been depleted by transduction of wild-type APC in SW480 cells. Expression of MT1-MMP was elevated in 22 of 24 colon carcinomas we examined. Reporter assays and an electromobility-shift assay revealed a DNA fragment between -1169 bp and -1163 bp in the 5' flanking region of this gene to be a target of the beta-catenin/Tcf4 complex. Our results indicate that MT1-MMP is a direct down-stream target in the Wnt signaling pathway, and that one of the ways accumulated beta-catenin contributes to colorectal carcinogenesis is by transactivating this gene.

Basigin (CD147) is expressed on melanoma cells and induces tumor cell invasion by stimulating production of matrix metalloproteinases by fibroblasts

EMMPRIN, which is identical to human basigin (CD147), interacts with fibroblasts and stimulates expression of MMPs, which play an important role in tumor invasiveness and metastasis. In the present study, we demonstrated that coculture of basigin-expressing human MM cells with dermal fibroblasts resulted in the induction of MMP-1, MMP-2, MMP-3 and MT1-MMP production by fibroblasts and of melanoma cell invasion through a reconstituted basement membrane. Antibody to basigin inhibited both the production of MMPs by fibroblasts and the invasiveness of melanoma cells. Expression of basigin and MMPs in MM and surrounding fibroblasts was examined immunohistochemically in 28 specimens from 18 MM patients without metastasis and 10 with metastasis, to investigate whether basigin plays a role in metastasis of MM in vivo. Basigin was expressed in melanoma cells but not in fibroblasts. MM with metastasis had significantly higher basigin expression compared to MM without metastasis. There were significant differences between MMs with and without metastasis in the expression of MMPs in both melanoma cells and fibroblasts. Expression of MMPs in fibroblasts was positively correlated with expression levels of basigin. These immunohistochemic findings indicate that MMPs might be expressed in fibroblasts as well as melanoma cells concomitantly with basigin, which was expressed in melanoma cells more frequently in MM with metastasis. Basigin is highly expressed in melanoma cells and may play an important role in their invasiveness and metastasis by stimulating surrounding fibroblasts to express MMPs.

Adhesion molecules

The exact mechanisms by which serous ovarian cancer cells invade through their underlying basement membrane or are released from the surface of the ovary have yet to be elucidated. This process undoubtedly has a complex molecular basis that most likely involves multiple cell surface receptors, basement membrane components, intercellular adhesion molecules, and signaling from the cell [137]. One possible mechanism by which ovarian carcinoma tumor cells may alter their basement membrane is by the synthesis and secretion of proteolytic enzymes that degrade their basement membranes [88-94, 138]. Alternatively, metastatic ovarian carcinoma cells may decrease their synthesis and/or secretion of ECM molecules. Additional studies are required to determine whether the more aggressive behavior of malignant ovarian carcinoma cells, compared to normal ovarian epithelial cells, is related to an altered cellular response towards ECM molecules, perhaps due to alterations in adhesion molecules/receptors. A further elucidation of the mechanisms by which serous ovarian carcinoma cells regulate their expression of ECM molecules and adhesion molecules/receptors will help in our understanding of the invasion and metastasis of tumor cells. Members of several families of adhesion molecules have been described that seem to be important in the progression of ovarian carcinoma, including CD44, integrins, and E-cadherin. Due to the complexity of this disease, it is likely that other adhesion molecules will also be implicated in the adhesion, migration, invasion, growth, proliferation, and apoptosis of ovarian carcinoma cells. Our group and others have shown that CD44 and the beta 1 integrin subunit play fundamental roles in the adhesion and migration of ovarian carcinoma cells to mesothelial cells and their associated pericellular matrix. Subsequent to the initial adhesion, the ovarian carcinoma cells may migrate through the layer of mesothelial cells, penetrate through the underlying basement membrane, invade into the tissue, and establish a secondary site of growth. Further studies will be required in order to fully understand the relationship of each adhesion molecule and their ligand(s) in the progression of this disease. Once the adhesion molecules and their ligand(s) for each step of the progression of this disease have been identified, it should be possible to develop reagents that can inhibit these interactions. Then, when ovarian carcinoma cells can no longer interact with mesothelial cells and their associated ECM, the dissemination of ovarian carcinoma cells in vivo may be prevented.

Immunohistochemical study of membrane type-matrix metalloproteinases (MT-MMPs) and matrix metalloproteinase-2 (MMP-2) in dermatofibroma and malignant fibrous histiocytoma

Matrix metalloproteinases (MMPs) play an important role in tumor invasion and metastasis. Enhanced expression of matrix metalloproteinase-2 (MMP-2) has been demonstrated in dermatofibroma (DF) and malignant fibrous histiocytoma (MFH). MMP-2 has been shown to be activated by membrane-type MMPs (MT-MMPs). To study the role of MT-MMP in the activation of MMP-2, skin specimens of DF (five cases) and MFH (three cases) were immunohistochemically studied using in situ zymography and the antibodies against matrix metalloproteinase-2 (MMP-2) and membrane type 1-3-MMPs (MT1-3-MMPs). Both MMP-2 activity and its expression were significantly activated in the tumor cells in DF and MFH. Anti-MT2-MMP strongly reacted with tumor cells of all cases of DF and MFH, whereas anti-MT1 or 3-MMP antibody showed a weak reaction in some cases of DF and MFH. Double immunofluorescence labeling demonstrated that the immunoreactive cells with anti-MMP-2 antibody in DF and MFH consistently reacted with anti-MT2-MMP antibody. The results suggest that the activation of MMP-2 in the benign and malignant fibrous tumors is related to the activation of MT-MMPs.