Increasing expression of serine protease matriptase in ovarian tumors: tissue microarray analysis of immunostaining score with clinicopathological parameters.

Matriptase is a type II transmembrane serine protease expressed by cells of surface epithelial origin, including epithelial ovarian tumor cells. Matriptase cleaves and activates proteins implicated in the progression of cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine the expression of matriptase in ovarian tumors and to assign clinicopathological correlations. Immunohistochemical analysis of matriptase was performed in tissue microarrays of 164 ovarian neoplasms including 84 serous adenocarcinomas, 23 mucinous adenocarcinomas, 10 endometrioid adenocarcinomas, six yolk sac tumors, 12 clear cell carcinomas, six dysgerminomas, eight granulosa cell tumors, four transitional cell carcinomas, five fibromas, and six Brenner tumors. All ovarian tumors except the fibromas and Brenner tumors showed significant expression of matriptase. The matriptase scores were significantly higher in the tumors than in their nontumor counterparts (304+/-26 for serous adenocarcinoma; 361+/-28 for mucinous adenocarcinoma; 254+/-17 for endometrioid adenocarcinoma; 205+/-19 for yolk sac tumor; 162+/-16 for clear cell carcinoma; 109+/-11 for dysgerminoma; 105+/-9 for granulosa cell tumor; and 226+/-18 for transitional cell carcinoma). Matriptase scores in serous adenocarcinoma were correlated with TNM stage and FIGO stage. Our findings demonstrate for the first time that matriptase is overexpressed in many malignant ovarian tumors. It may be a novel biomarker for diagnosis and treatment of malignant ovarian tumors.

Expression of 72 kilodalton type IV collagenase (gelatinase A) in benign and malignant ovarian tumors.

BACKGROUND: 72 Kilodalton (kd) type IV collagenase is a matrix metalloproteinase that specifically cleaves type IV collagen molecules. The enzyme has been postulated to have an important role in the invasion and spread of malignant tumors. EXPERIMENTAL DESIGN: In situ hybridization was used to study the expression of the 72 kd type IV collagenase mRNA in 24 benign, 2 semimalignant, and 15 malignant ovarian tumors and in 5 metastases of ovarian serous adenocarcinomas. The results were correlated with the expression of the mRNA for the alpha 1(IV) chain of type IV collagen and with the corresponding immunohistochemical distribution of the enzyme. RESULTS: The results showed that the more malignant an ovarian tumor was, the more clearly mRNA expressions for both 72 kd type IV collagenase and the alpha 1(IV) chain could be detected in tumor cells. The expression of both types of mRNAs was localized within the cells of tumor stroma and occurred mainly in fibroblasts and vascular endothelial cells. Epithelial tumor cells only rarely expressed these mRNAs. Immunohistochemical stainings localized the 72 kd collagenase as well to the stromal cells as to the epithelial cells of both benign and malignant tumors. CONCLUSIONS: The findings indicate that genes for the 72 kd type IV collagenase and for its substrate are simultaneously active in the same cells of the tumor stroma. The difference in the in situ hybridization and immunohistochemical findings could be explained by a possible variation in the metabolic balance between synthesis and accumulation of the protein in different cell types. It can also be proposed that the activity of the 72 kd type IV collagenase would be mediated through a receptor-like mechanism present on epithelial cells which could bind the 72 kd type IV collagenase synthesized elsewhere. There is also a possibility that the gelatinolytic activity of the mesenchymally synthesized 72 kd type IV collagenase would be consumed to degrade extracellular matrix proteins other than basement membranes.