DIFFERENTIAL EXPRESSION OF TRYPSIN IN HUMAN OVARIAN CARCINOMAS AND LOW-MALIGNANT-POTENTIAL TUMORS

It is widely recognized that matrix metalloproteinases and serine prot einases play an important role in cancer invasion and metastasis. We h ave reported that trypsin is synthesized in ovarian carcinomas as well as in some other types of cancers. In general, ovarian cancers easily tend to invade, metastasize, and spread widely into the peritoneal ca vity. However, low-malignant-potential (LMP, borderline tumor) ovarian tumors are known to have limited malignant potential for progression, although microinvasion and distant metastasis have been reported amon g them. To analyze the relationship between varied degrees of trypsin expression and malignant behavior of ovarian tumors, immunohistochemic al studies with monoclonal antibodies to human trypsin and clinicopath ologic analysis were performed in human ovarian carcinomas, low-malign ant-potential tumors, and benign cystadenomas. Thirteen (44.8%) cases of 29 ovarian carcinomas showed prominent trypsin expression, while on ly 2 (18.2%) cases of 11 LMP ovarian tumors demonstrated low levels of expression. Benign tumors and normal ovaries did not show any positiv ity for trypsin. These data suggest that tumor-derived heterotropic tr ypsin may be associated with ovarian tumors in parallel with malignant potential or behavior such as invasiveness or metastasis. At least in some ovarian carcinomas, prominent stromal invasion or metastasis mig ht require the acquisition of or association with tumor-derived trypsi n production. (C) 1998 Academic Press.