Activated matrix metalloproteinase-2--a potential marker of prognosis for epithelial ovarian cancer

Selected Matrix Metalloproteinases (MMP-2, MMP-7) and Their Inhibitor (TIMP-2) in Adult and Pediatric Cancer

The tumor microenvironment (TME) consists of numerous biologically relevant elements. One of the most important components of the TME is the extracellular matrix (ECM). The compounds of the ECM create a network that provides structural and biochemical support to surrounding cells. The most important substances involved in the regulation of the ECM degradation process are matrix metalloproteinases (MMPs) and their endogenous inhibitors (tissue inhibitors of metalloproteinases, TIMPs). The disruption of the physiological balance between MMP activation and deactivation could lead to progression of various diseases such as cardiovascular disease, cancer, fibrosis arthritis, chronic tissue ulcers, pathologies of the nervous system (such as stroke and Alzheimer's disease), periodontitis, and atheroma. MMP-TIMP imbalance results in matrix proteolysis associated with various pathological processes such as tumor invasion. The present review discusses the involvement of two MMPs, MMP-2 and MMP-7, in cancer pathogenesis. These two MMPs have been proven in several studies, conducted mostly on adults, to make an important contribution to cancer development and progression. In the current review, several studies that indicate the importance of MMP-TIMP balance determination for the pediatric population are also highlighted. The authors of this review believe that carrying out biochemical and clinical studies focused on metalloproteinases and their inhibitors in tumors in children will be of great relevance for future patient diagnosis, determination of a prognosis, and monitoring of therapy.

Vaccination with gamma radiation-attenuated Toxoplasma gondii protects against ovarian infiltration in mice-bearing Ehrlich ascites carcinoma

Purpose: Cancer is one of the most common causes of mortality and morbidity worldwide. Vaccines have been emerged as an attractive approach for their capacity of eliciting long-term immune response targeting cancer cells. Attenuated avirulent Toxoplasma gondii stimulate immunity and activate antitumor cells thereby eliciting rejection of some established cancer. The purpose of this study was to evaluate the antitumor-protective capacity of vaccination with gamma radiation-attenuated T. gondii against ovarian penetration in Ehrlich ascites carcinoma (EAC)-bearing mice.Materials and methods: Forty-five mice were randomly divided into three groups as follows: nontumor-bearing (normal control); EAC-bearing group (EAC); and mice vaccinated orally with gamma radiation-attenuated T. gondii then inoculated 2 weeks later with EAC (TG + EAC). Survival rate, serum interleukin-12 (IL-12), and levels of IFN-γ mRNA, CD4, and CD8 in ovarian tissues homogenate were assessed. Also, ovarian histopathology and immunohistochemical expressions of metalloproteinase-2, CD34, and vimentin were determined.Results: The group vaccinated with attenuated T. gondii showed significantly increased survival rates, serum IL-12, and levels of IFN-γ, CD4, and CD8 in ovarian tissue homogenates as well as an enhancement of histopathological and immunohistochemical changes compared to EAC-bearing group.Conclusion: Vaccination with gamma radiation-attenuated T. gondii has the capacity to supply immunoprotective impact against ovarian invasion in EAC-bearing mice.

Nerve growth factor modulates the tumor cells migration in ovarian cancer through the WNT/β-catenin pathway

Nerve growth factor (NGF)/nerve growth factor receptors (NGFRs) axis and canonical WNT/β-catenin pathway have shown to play crucial roles in tumor initiation, progression and prognosis. But little did we know the relationship between them in modulation of tumor progress. In this report, we found that NGF/NGFRs and β-catenin were coexpression in ovarian cancer cell lines, and NGF can decrease the expression level of β-catenin and affect its activities, which may be related to the NGF-induced down-regulation of B-cell CLL/lymphoma 9-like (BCL9L, BCL9-2). Furthermore, NGF can also increase or decrease the downstream target gene expression levels of WNT/β-catenin depending on the cell types. Especially, we created a novel in vitro cell growth model based on a microfluidic device to intuitively observe the effects of NGF/NGFRs on the motility behaviors of ovarian cancer cells. The results showed that the migration area and maximum distance into three dimensional (3D) matrigel were decreased in CAOV3 and OVCAR3 cells, but increased in SKOV3 cells following the stimulation with NGF. In addition, we found that the cell colony area was down-regulated in CAOV3 cells, however, it was augmented in OVCAR3 cells after treatment with NGF. The inhibitors of NGF/NGFRs, such as Ro 08-2750, K252a and LM11A-31,can all block NGF-stimulated changes of gene expression or migratory behavior on ovarian cancer cells. The different results among ovarian cancer cells illustrated the heterogeneity and complexity of ovarian cancer. Collectively, our results suggested for the first time that NGF is functionally linked to β-catenin in the migration of human ovarian cancer cells, which may be a novel therapeutic perspective to prevent the spread of ovarian carcinomas by studying the interaction between NGF/NGFRs and canonical WNT/β-catenin signaling.

A Specific Mixture of Nutrients Suppresses Ovarian Cancer A-2780 Tumor Incidence, Growth, and Metastasis to Lungs

Ovarian cancer is the deadliest gynecological malignancy in women, and fifth leading cause of death. Despite advances made in chemotherapy and surgery, the average time of clinical remission is approximately 2 years and the 5-year survival rate is 45%. Thus, there is an urgent need for the development of a novel therapeutic approach to ovarian cancer treatment. We investigated the effect of a specific nutrient mixture (EPQ) containing ascorbic acid, lysine, proline, green tea extract, and quercetin on human ovarian cancer cell A-2780 in vivo and in vitro. Athymic female nude mice (n = 12) were all inoculated intraperitoneally (IP) with 2 × 10⁶ cells in 0.1 mL of phosphate buffered saline (PBS) and randomly divided into two groups. Upon injection, the Control group (n = 6) was fed a regular diet and the EPQ group (n = 6) a regular diet supplemented with 0.5% EPQ. Four weeks later, the mice were sacrificed and tumors that developed in the ovary were excised, weighed, and processed for histology. Lungs were inspected for metastasis. In vitro, A-2780 cells were cultured in Dulbecco modified Eagle medium supplemented with 10% FBS and antibiotics. At near confluence, cells were treated with EPQ in triplicate at concentrations between 0 and 1000 μg/mL. Cell proliferation was measured via MTT assay, MMP-9 secretion via gelatinase zymography, invasion through Matrigel and morphology via hematoxylin and eosin (H & E) staining. All Control mice developed large ovarian tumors, whereas 5 out of 6 mice in the EPQ group developed no tumors, and one, a small tumor. Control mice also showed lung metastasis in 6 out of 6 mice, while no lung metastasis was evident in EPQ mice. Zymography demonstrated only MMP-9 expression, which EPQ inhibited in a dose-dependent fashion, with virtual total block at 250 μg/mL concentration. EPQ significantly inhibited invasion through Matrigel with total block at 250 μg/mL concentration. MTT showed dose-dependent inhibition of cell proliferation with EPQ, and H & E staining showed no morphological changes below 500 μg/mL EPQ. These results suggest that EPQ has therapeutic potential in the treatment of ovarian cancer by significantly suppressing ovarian tumor incidence and growth and lung metastasis, and by inhibiting MMP-9 secretion and invasion of A-2780 ovarian cancer cells.

Prognostic value of MMP-2 for patients with ovarian epithelial carcinoma: a systematic review and meta-analysis

BACKGROUND

The reported roles of matrix metalloproteinase 2 (MMP-2) on the prognosis of patients with epithelial ovarian cancers (EOCs) are inconsistent.

OBJECTIVE

This meta-analysis was performed to evaluate the prognostic significance of MMP-2 for patients with EOCs by analyzing 11 studies.

METHODS

We systematically searched articles in the Cochrane Library, Pubmed, Embase, China National Knowledge Infrastructure (CNKI), Wanfang Database, and Chinese Biological Medical (CBM) Database, updated to February 1^st 2015, with the following search terms: ovarian neoplasm OR ovarian tumor OR ovarian carcinoma OR ovarian malignance OR ovarian cancer AND matrix metalloproteinase-2 OR MMP-2.

RESULTS

A total of 11 studies involving 1058 patients with EOCs were in accordance with the inclusion criteria. The pooled HR was 1.09 (95% CI 0.32-1.86, p = 0.006) in patients with overexpression of stromal MMP-2 with significant heterogeneity (I ² = 53.1%, p = 0.074) between studies. For patients with MMP-2 overexpression in tumor cells, the pooled HR was 1.42 (95% CI 1.14-1.70, p = 0.000) with no significant heterogeneity (I ² = 43.4%, p = 0.078) between studies. Sensitivity analyses were stable.

CONCLUSIONS

MMP-2 overexpression in tumor cells rather than stroma was significantly associated with poor prognosis in patient with endothelial ovarian cancer; however, the result remains to be confirmed with additional high-quality studies.

The C3G/Rap1 pathway promotes secretion of MMP-2 and MMP-9 and is involved in serous ovarian cancer metastasis

Complete resection is pivotal to improve survival to epithelial ovarian cancer (EOC). Crk SH3-domain-binding guanine nucleotide-releasing factor (C3G) is involved in multiple signaling pathways and it has opposite roles in different cancers. The present study aimed to identify C3G expression in ovarian tissue samples from patients with EOC and to explore its association with tumor grade. Eighty-seven archival paraffin-embedded, formalin-fixed, ovarian cancer tissues with serous histology were stained for C3G by immunohistochemistry. To evaluate the contribution of C3G to Rap1 activity, 36 patients with serous ovarian cancer (SOC) were investigated. Additionally, C3G was knocked down in SKOV3 and HEY cells. C3G regulated Rap1 activity and high Rap1 activity was correlated with poor differentiation, advanced FIGO stage, and unsuccessful cytoreductive surgery of SOC. Knockdown of C3G suppressed cell invasion, intravasation and extravasation, and reduced Rap1 activity and secretion of matrix metalloproteinase (MMP)-2 and MMP-9. C3G-mediated activation of Rap1 could direct the tumor pattern of human SOC by promoting the secretion of MMP-2 and MMP-9. These results suggest that C3G is involved in the metastatic spread of EOC.

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.

Establishment of a new representative model of human ovarian cancer in mice

Background

Intraperitoneal (i.p.) models that accurately mimic the feature behavior of human ovarian cancer are required to investigate the pathology and therapeutics of the disease. However, established i.p. models which are well-characterized and reliable are few. The purposes of this study are to establish a representative mice i.p. model of the disease and to analyze the consequent pathology.

Methods

Fresh tumor cells fiom the ascites of patient were injected into female NOD/SCID mice intraperitoneally. Histology, Cytogenetic, immunohistochemistry,tumor markers of CA125,AFP, CA-199 and CEA were used to analyze the model.

Results

The mice developed marked abdominal distention within 6 months after inoculated with tumor cells from a patient with epithelial ovarian carcinoma. The mice developed clinically evident intraperitoneal tumors and massive ascites containing numerous tumor cells in clumps. CA125 level in our model was high in both serum and ascites supernatants, while levels of other tumor markers, such as AFP, CA-199 and CEA, were normal. Cytogenetic analysis and immunohistochemical staining confirmed its characteristics resembling human epithelial ovarian tumor.

Conclusions

The model described in this paper accurately mimics the features of ovarian tumor, which may be useful for evaluation of new therapeutics.

Angiogenic alterations associated with circulating neoplastic DNA in ovarian carcinoma

OBJECTIVES

Forty percent of women with ovarian carcinoma have circulating free neoplastic DNA identified in plasma. Angiogenesis is critical in neoplastic growth and metastasis. We sought to determine whether circulating neoplastic DNA results from alterations in the balance of angiogenesis activators and inhibitors.

METHODS

Sixty patients with invasive ovarian carcinomas with somatic TP53 mutations that had been characterized for circulating neoplastic DNA had carcinoma analyzed for microvessel density using immunohistochemistry with CD31 and for the expression of VEGF, ANGPT1, ANGPT2, PTGS2, PLAU, THBS1, CSF1, PIK3CA, HIF1A, IL8, MMP2, and MMP9 message by real-time quantitative polymerase chain reaction. The expression of each gene was calculated relative to GAPDH expression for each neoplasm. Patient plasma had been tested for circulating neoplastic DNA using a ligase detection reaction.

RESULTS

MMP2 expression was significantly correlated with free plasma neoplastic DNA (P = .007). Microvessel density was not correlated with plasma neoplastic DNA or BRCA1/2 mutation status. The expression pattern of other angiogenic factors did not correlate with plasma neoplastic DNA but correlated with each other. BRCA1/2 mutated carcinomas had significantly different expression profiles of angiogenesis activators and inhibitors in comparison to sporadic carcinomas.

CONCLUSIONS

MMP2 expression is associated with the presence of circulating neoplastic DNA in women with ovarian carcinoma. These data are consistent with the proinvasive properties of MMP2 and suggest that the presence of circulating neoplastic DNA indicates a more aggressive malignant phenotype. Carcinomas with germ line BRCA1/2 mutations had a lower angiogenic profile than those without mutations.

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.

Liposomal Tumor Targeting in Drug Delivery Utilizing MMP-2- and MMP-9-Binding Ligands

Nanotechnology offers an alternative to conventional treatment options by enabling different drug delivery and controlled-release delivery strategies. Liposomes being especially biodegradable and in most cases essentially nontoxic offer a versatile platform for several different delivery approaches that can potentially enhance the delivery and targeting of therapies to tumors. Liposomes penetrate tumors spontaneously as a result of fenestrated blood vessels within tumors, leading to known enhanced permeability and subsequent drug retention effects. In addition, liposomes can be used to carry radioactive moieties, such as radiotracers, which can be bound at multiple locations within liposomes, making them attractive carriers for molecular imaging applications. Phage display is a technique that can deliver various high-affinity and selectivity peptides to different targets. In this study, gelatinase-binding peptides, found by phage display, were attached to liposomes by covalent peptide-PEG-PE anchor creating a targeted drug delivery vehicle. Gelatinases as extracellular targets for tumor targeting offer a viable alternative for tumor targeting. Our findings show that targeted drug delivery is more efficient than non-targeted drug delivery.

Lysophosphatidic acid (LPA) effects on endometrial carcinoma in vitro proliferation, invasion, and matrix metalloproteinase activity

OBJECTIVES

Lysophosphatidic acid (LPA) has potent growth-regulatory effect in many cell types and has been linked to the in vivo tumor growth and metastasis in several malignancies. The goal of this study was to assess the regulation of (EC) microenvironment by LPA through the examination of its effect on cell proliferation, migration, invasion, uPA activity, and matrix metalloproteinase (MMP) secretion/activation.

METHODS

All experiments were performed in vitro using an EC cell line, HEC-1A. Cell proliferation was determined using the Promega MTS proliferation assay following 48 h of exposures to different concentrations of LPA (0.1, 1.0 and 10.0 microM). Cell invasion was assessed using a modified Boyden chamber assay with collagen I coated on the membrane. HEC-1A motility was examined by Boyden chamber migration assay as well as the scratch wound closure assay on type I collagen. MMP secretion/activation in HEC-1A conditioned medium was detected by gelatin zymography. MMP-7 mRNA expression was determined using real-time PCR. uPA activity was measured using a coupled colorimetric assay.

RESULTS

LPA, at the concentrations of 0.1 and 1.0 microM, significantly induced the proliferation of HEC-1A cells (p<0.01). At 10 microM, LPA- induced HEC-1A proliferation to a less extent and showed no significant effect on HEC-1A invasion and migration (p>0.05). Gelatin zymogram showed that HEC-1A cells secreted high levels of MMP-7, while MMP-2 and MMP-9 are barely detectable. In addition, LPA significantly enhanced uPA activity in HEC-1A conditioned medium in a concentration-dependent manner.

CONCLUSIONS

LPA is a potent modulator of cellular proliferation and invasion for EC cells. It also has the capacity to stimulate the secretion/activity of uPA and MMP-7. Those results suggest that LPA is a bioactive modulator of EC microenvironment and may have a distinct regulation mechanism as observed in epithelial ovarian cancer.

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.

Clinical significance of serum MMP-2 and MMP-7 in patients with ovarian cancer

Matrix metalloproteinases (MMPs) are frequently expressed in malignant tumors and play an important role in tumor invasion and metastasis. The aim of this study was to evaluate role of serum MMP-2 and MMP-7 levels in patients with ovarian cancer. Serum levels of MMP-2 and MMP-7 were measured in 28 patients with ovarian carcinoma, 2 with borderline ovarian tumors, 10 with non-malignant gynecological disease and 30 healthy women by Enzyme-Linked Immunosorbent Assay (ELISA). Serum MMP-7 level was significantly (10.24+/-1.35 ng/ml) higher in the patients with ovarian malign tumors than healthy controls (3.29+/-1.64 ng/ml) (P<0.05). Postoperative levels of MMP-7 (7.68+/-1.17 ng/ml) were significantly lower in patients with malign ovarian tumors than those of preoperative level (10.24+/-1.35 ng/ml) (P<0.05). Serum MMP-2 levels were significantly lower in the patients with ovarian malign tumors (227.51+/-9.91 ng/ml) than those in the healthy controls (279.12+/-73 ng/ml) (P<0.05). There was no significant difference in serum levels of MMP-2 and MMP-7 in patients with benign ovarian disease when compared to healthy controls and patients with malignant disease (P>0.05). As a conclusion, MMP-7 can be a useful serum marker to show disease activity in malignant ovarian tumors.

Prognostic significance of extracellular matrix metalloproteinase inducer and matrix metalloproteinase 2 in epithelial ovarian cancer

AIMS

We investigated the prognostic significance of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase 2 (MMP-2) in epithelial ovarian cancer as well as their relation to hyaluronan (HA) expression.

METHODS

The expression of EMMPRIN and MMP-2 was analyzed immunohistochemically in 295 primary epithelial ovarian cancer patients and 67 metastases.

RESULTS

A low membranous EMMPRIN expression was detected more often in serous tumors than in other types (p < 0.0005) and it was associated with tumors of advanced stage (p = 0.012) or with a large primary residual (p = 0.011). A low expression of MMP-2 in cancer cells was associated with a high histologic grade (grade 3) of the tumor (p = 0.005) and endometrioid type of tumors (p < 0.0005). Stromal MMP-2 expression was significantly associated with strong stromal HA expression (p = 0.002, r = 0.187). In univariate analysis, 10-year disease-related (DRS) and recurrence-free survivals were significantly better when MMP-2 expression in cancer cells was high (p = 0.0057 and p = 0.0467, respectively). DRS was also better when membranous EMMPRIN expression was high (p = 0.013). In multivariate analysis, strong MMP-2 in cancer cells (RR = 1.48, CI = 1.07-2.04, p = 0.017) indicated favorable DRS.

CONCLUSION

Our results show that EMMPRIN and MMP-2 in cancer cells are significant indicators of a favorable prognosis of epithelial ovarian cancer.

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.

Inhibition of Matrilysin Expression by Antisense or RNA Interference Decreases Lysophosphatidic Acid–Induced Epithelial Ovarian Cancer Invasion

Our previous reports show that matrilysin [matrix metalloproteinase (MMP)-7] is overexpressed in epithelial ovarian cancer (EOC) and recombinant MMP-7 promotes EOC invasion in vitro. In the present study, we further evaluated the correlation of MMP-7 expression to EOC invasiveness and examined its role in lysophosphatidic acid (LPA)-induced invasion. By sense and antisense gene transfection in vitro, we show that overexpression of MMP-7 in all MMP-7 stably transfected DOV13 clones significantly enhanced their invasiveness, although MMP-7 antisense transfection caused a 91% decrease of MMP-7 expression (P < 0.01) and 87% decrease of invasion (P < 0.05) in geneticin (G418)-selected DOV13 clone P47-M7As-3 compared with vector-transfected control. As assessed by MMP-7 ELISA, LPA treatment at 10 to 80 micromol/L significantly stimulated the secretion of total MMP-7 in DOV13 conditioned medium (P < 0.01). In addition, LPA apparently induced the activation of MMP-7 in DOV13 cells as detected by gelatin zymography. In the antisense MMP-7-transfected DOV13 clone (P47-M7As-3), LPA-increased invasion was significantly decreased compared with vector control. Moreover, knocking down of MMP-7 by small interfering RNA also suppressed LPA-induced invasion in two EOC cell lines (DOV13 and R182). Altogether, our results show that MMP-7 expression is correlated with EOC invasiveness and LPA-induced MMP-7 secretion/activation may represent a new mechanism that facilitates ovarian cancer invasion besides the well-known induction of MT1-MMP-mediated proMMP-2 activation by LPA.

Prognostic significance of matrix metalloproteinase-9 (MMP-9) in epithelial ovarian cancer

OBJECTIVE

We investigated the expression of matrix metalloproteinase-9 (MMP-9) and its relation to clinicopathologic factors and survival and also to previously analyzed expressions of CD44 and hyaluronan in epithelial ovarian cancer.

METHODS

The expression of MMP-9 was analyzed immunohistochemically in 292 primary tumors and their 31 metastases.

RESULTS

A low proportion of strong MMP-9 expression in cancer cells and high stromal MMP-9 expression correlated with advanced stage of the tumor (p=0.003, p=0.02, respectively). Stromal MMP-9 expression significantly correlated with hyaluronan positivity (p<0.0005), whereas MMP-9 did not correlate with CD44. In univariate analysis, a longer 10-year disease-related survival (DRS) was found in patients with a high proportion of MMP-9 or strong MMP-9 expression in cancer cells (p=0.02, p=0.05, respectively). However, high stromal expression of MMP-9 indicated short DRS (p=0.01). In multivariate analysis of all patients, MMP-9 expressing cancer or stromal cells were not independent prognostic factors, while in FIGO stage I patients a high percentage of MMP-9 positive cancer cells was associated with long DRS (p=0.008).

CONCLUSION

These data suggest that MMP-9 has a dual role in tumor progression, acting against tumor advancement when in tumor epithelium and promoting tumor progression while in the stroma.

Expression of matrix metalloproteinase-26 and tissue inhibitors of metalloproteinase-3 and -4 in normal ovary and ovarian carcinoma

The objective of this study was to determine the spatial expression of matrix metalloproteinases (MMPs) and their physiologic inhibitors, the tissue inhibitor of MMP (TIMP)-3 and TIMP-4, in ovarian carcinoma compared to normal ovaries. Immunohistochemistry was carried out in this study. Tissue sections prepared from normal ovarian tissues from throughout the menstrual cycle (N = 20) and ovarian carcinomas (N = 45) characterized as stage I (N = 5), stage III/IV (N = 40) were immunostained using polyclonal antibodies to the latent and the active form of MMP-26, TIMP-3, and a monoclonal antibody to TIMP-4. Immunoreactive MMP-26, TIMP-3, and TIMP-4 were detected in all the ovarian cell types in normal and tumor tissues. In normal ovarian tissues, theca externa and luteal cells immunostained with high intensity for MMP-26 and TIMPs while theca/granulosa cell staining intensity increased as lutenization progressed. There was low immunostaining of the ovarian stromal and surface epithelial cells for MMP-26, with moderate staining for TIMPs. In the carcinoma specimens, cancer cells and vascular endothelial cells displayed the highest staining intensity compared to adjacent nontumor areas. The immunostaining intensity of MMP-26 and TIMP-3 increased with stage of tumor with the invading tumor cells displaying the strongest immunostaining. MMP-26, TIMP-3, and TIMP-4 are expressed in normal ovarian as well as ovarian tumors with elevated expression in the invasive tumor cells suggesting a potential role for MMP-26 in normal ovary and ovarian cancer biologic function.

Matrilysin (MMP-7) promotes invasion of ovarian cancer cells by activation of progelatinase

Although matrilysin (MMP-7) is overexpressed in various malignancies, few studies have evaluated its role in epithelial ovarian cancer (EOC) invasion and metastasis. We report that the secretion of MMP-7 in EOC is stimulated significantly by vascular endothelial growth factor (VEGF) and interlukin-8 (IL-8). We also examined the in vivo expression of MMP-7 in EOC and its effects on the in vitro invasion and progelatinase activation. We report that MMP-7 is overexpressed in ovarian cancer cell lines and EOC surgical specimens. DOV13 cells incubated with active rhMMP-7 significantly increased cellular invasion and proMMP-2 activation. RhMMP-7 also showed the ability to activate proMMP-2 and proMMP-9 in immortalized ovarian epithelial cell (IOSE-29) conditioned medium. In addition, rhMMP-7 was able to activate progelatinase in a concentration-dependent manner in vitro. TIMP-2 or the generic MMP inhibitor-GM6001 inhibited both the activation of proMMP-2 and the increased invasion of DOV13 cells promoted by rhMMP-7. By incubation of MMP2-TIMP-2 complex with equal molar rhMMP-7, MMP-2 was dissociated from the complex and activated in a time-dependent manner, suggesting that TIMP-2 helps to keep the latency of MMP-2. TIMP-2 also showed inhibitory effects on the MMP-7 induced increase of gelatinolytic activity in DOV13 and IOSE-29 conditioned media. A strong co-localization of MMP-7 and MMP-2 was observed in DOV13 cells and ovarian carcinoma permanent tissue sections. These results indicate MMP-7 is overexpressed in malignant ovarian epithelium and suggest MMP-7 may facilitate tumor cell invasion in vivo partly through the induction of progelatinase activation.

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.

Human kallikrein 13 involvement in extracellular matrix degradation

The human kallikrein family is a group of 15 serine protease genes clustered on chromosome 19q13.4 and shares a high degree of homology. These proteolytic enzymes have diverse physiological functions in many different tissues. Growing evidence suggests that many kallikreins are differentially expressed in cancer and may play a role in metastasis. Human kallikrein gene 13 (KLK13) is a member of this family and codes for a trypsin-like, secreted serine protease (hK13) that is overexpressed in ovarian cancer patients. The aim of this study was to determine if hK13 can degrade extracellular matrix components. Recombinant hK13 was produced in yeast and purified using cation exchange and reverse-phase chromatography. The protein was used as an immunogen to generate mouse monoclonal antibodies. Enzymatic activity of hK13 was verified by using synthetic tri-peptide fluorogenic substrates and gelatin zymography. Active hK13 was incubated with biotinylated extracellular matrix (ECM) proteins and degradation was evaluated by Western blot analysis. hK13-secreting cancer cell lines were treated in a chemotaxis invasion chamber that was coated with various ECM proteins, to determine if hK13 plays a role in tumor cell migration and invasion. Assay with the synthetic substrates and zymography have shown that recombinant hK13 was enzymatically active. The Western blot results showed that hK13 was able to cleave the major components of the extracellular matrix. In the chemotaxis invasion chamber experiment, it was found that ovarian cancer cell lines that secreted hK13 and were treated with an hK13 neutralizing antibody migrated less than untreated cells. Human kallikrein13 may play a role in tissue remodeling and/or tumor invasion and metastasis. Targeting hK13 activity with neutralizing antibodies may have therapeutic applications.

Human kallikrein 13 protein in ovarian cancer cytosols: a new favorable prognostic marker

PURPOSE

Human kallikrein 13 (hK13; encoded by the KLK13 gene) is a secreted serine protease expressed in endocrine tissues, including the prostate, testis, breast, and ovary. We have previously reported steroid hormone regulation of the KLK13 gene and its clinical value as a marker of favorable prognosis in breast cancer at the mRNA level. We hypothesized that hK13 may represent a potential biomarker for ovarian carcinomas.

PATIENTS AND METHODS

Using a newly developed enzyme-linked immunosorbent assay (ELISA), hK13 levels were quantified in 131 ovarian tumor extracts and correlated with various clinicopathological variables and outcome (progression-free survival [PFS], overall survival [OS]), over a median follow-up period of 42 months.

RESULTS

hK13 concentration in ovarian tumor cytosols ranged from 0 to 18.4 ng/mg of total protein. An optimal cutoff value of 0.13 ng/mg (67(th) percentile) was selected, based on the ability of hK13 values to predict the PFS of the study population, to categorize tumors as hK13-positive or negative. Women with hK13-positive tumors most often had early stage (stage I/II) disease, no residual tumor after surgery and optimal debulking success (P <.05). Univariate and multivariate Cox regression analyses revealed that patients with hK13-positive tumors had a significantly longer PFS and OS than hK13-negative patients (P <.05). Kaplan-Meier survival curves further confirmed a reduced risk of relapse and death in women with hK13-positive tumors (P =.007 and P =.002, respectively).

CONCLUSION

These results indicate that hK13 is an independent marker of favorable prognosis in ovarian cancer.

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.

Cytokine-regulated expression of collagenase-2 (MMP-8) is involved in the progression of ovarian cancer

Matrix metalloproteinases (MMPs) have been implicated in ovarian cancer progression. Among them, MMP-8 that degrades type I collagen may play a crucial role. The aim of our study was to determine MMP-8 expression and regulation in ovarian cancer and its association with other MMPs and tissue inhibitors of metalloproteinases (TIMPs). Tissue microarrays (TMAs) containing tissue cylinders from 302 patients were used for immunohistochemical studies. In addition, MMP-8 expression in vitro was analysed by a specific immunoassay and PCR-analysis. MMP-7 (81%), MMP-8 (95%), MT3-MMP (100%), TIMP-2 (100%), and TIMP-3 (96%) were expressed in all the OVCAs, but the staining intensities varied. MMP-3 (6%), MMP-9 (57%) and TIMP-1 (43%) expressions were more rarely detected. Only MMP-8 expression levels correlated with tumour grade (P<0.01), tumour stage (P<0.01), and a poor prognosis (P<0.05). MMP-8 protein and gene expression in vitro was found to be significantly upregulated by interleukin-1beta (IL-1beta, P<0.01). The data indicate that MMP-8 overexpression in OVCAs is regulated by IL-1beta and that pro-inflammatory cytokines may promote the invasive potential of ovarian cancer.

Targeted therapy for epithelial ovarian cancer: Current status and future prospects

Despite advances in surgery and chemotherapy, less than 20% of patients with stage III or IV ovarian cancer survive long-term. In the past, cytotoxic regimens have been developed empirically, combining active agents at maximally tolerated doses, often without a clear rationale for their interaction. Advances in understanding the biology of ovarian cancer have identified multiple molecular targets that differ in normal and malignant cells. Targets include cell cycle regulators, growth factor receptors, signal transduction pathways, molecules that confer drug resistance, and angiogenic mechanisms. A number of targeted agents have entered clinical trials. Small molecular weight inhibitors, monoclonal antibodies, and antisense and gene therapy are all being evaluated alone and in combination with cytotoxic drugs. In contrast to earlier studies, the impact of each agent on the designated target can be assessed and agents can be matched to the genotype and phenotype of malignant and normal cells. In the long run, this should facilitate individualization of more effective, less toxic therapy for women with ovarian cancer.

Identification of biomarkers for ovarian cancer using strong anion-exchange ProteinChips: potential use in diagnosis and prognosis

One hundred eighty-four serum samples from patients with ovarian cancer (n = 109), patients with benign tumors (n = 19), and healthy donors (n = 56) were analyzed on strong anion-exchange surfaces using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry technology. Univariate and multivariate statistical analyses applied to protein-profiling data obtained from 140 training serum samples identified three biomarker protein panels. The first panel of five candidate protein biomarkers, termed the screening biomarker panel, effectively diagnosed benign and malignant ovarian neoplasia [95.7% sensitivity, 82.6% specificity, 89.2% accuracy, and receiver operating characteristic (ROC) area under the curve of 0.94]. The other two panels, consisting of five and four candidate protein biomarkers each, effectively distinguished between benign and malignant ovarian neoplasia and were therefore referred to as validation biomarker panel I (81.5% sensitivity, 94.9% specificity, 88.2% accuracy, and ROC = 0.94) and validation biomarker panel II (72.8% sensitivity, 94.9% specificity, 83.9% accuracy, and ROC = 0.90). The three ovarian cancer biomarker protein panels correctly diagnosed 41 of the 44 blinded test samples: 21 of 22 malignant ovarian neoplasias [10 of 11 early-stage ovarian cancer (I/II) and 11 of 11 advanced-stage ovarian cancer (III/IV)], 6 of 6 low malignant potential, 5 of the 6 benign tumors, and 9 of 10 normal patient samples. In conclusion, we have discovered three ovarian cancer biomarker protein panels that, when used together, effectively distinguished serum samples from healthy controls and patients with either benign or malignant ovarian neoplasia.

Urinary matrix metalloproteinases as a potential screening test for gynecologic malignancies

OBJECTIVE

This was a pilot study to determine the feasibility of using urinary matrix metalloproteinases (MMPs) as a screening test for gynecologic malignancies.

METHODS

Urine samples from ovarian (n = 29), cervical (n = 31), endometrial (n = 31), and vulvar (n = 5) cancer patients and 19 controls were collected. Substrate gel electrophoresis (zymography) was used to determine the presence of MMP-2 (72 kDa), MMP-9 (92 kDa) and two high-molecular-weight forms (130 and 220 kDa) of MMPs. The sensitivity, specificity, and positive and negative predictive values of the test for each tumor type were determined.

RESULTS

No association was noted between malignancy and presence of urinary MMPs in ovarian, cervical, endometrial, or vulvar cancer patients. Sensitivity, specificity, negative and positive predictive values, and likelihood ratios were determined. Sensitivities ranged from 28.1 to 51.0% for individual MMPs, peaking at 69.8% when the presence of any of the four proteinases was considered a positive test. Specificities ranged from 42.1 to 68.4%.

CONCLUSION

Our study suggests that the presence of MMPs in the urine of patients with a gynecologic malignancy is not an adequate screening test for disease. There was also little evidence of an association between urinary MMPs and stage or extent of disease. However, the limited number of patients in the various stages of each disease site, specifically advanced stage disease, make it difficult to state this definitively.