Changes in expression of differentiation markers between normal ovarian cells and derived tumors

The marker profile of 18 samples of normal human ovarian tissues and 138 samples of their derived tumors was established using 51 monoclonal antibodies directed against intermediate filaments, ovarian carcinoma-specific antigens, general tumor-associated antigens and MHC-I/II antigens. Our data show that vimentin and keratins 7, 8, 18, and 19 were found in both epithelial and some nonepithelial ovarian tumors. Several tumor samples contained additional keratins 4, 10, 13, and 14, as well as desmin. BW 495/36 and to a lesser extent HMFG-2 were usually found in all ovarian tumors that contained simple epithelial keratins, except the absence of HMFG-2 in gonadal tumors as well as in dysgerminomas. In contrast to the keratin antibodies, these two panepithelial antibodies were negative in normal mesothelial cells and granulosa cells of the ovarian follicles. In general, the marker TAG-72 appeared useful for its discrimination between positively stained mucinous adenomas, the ovarian carcinomas as well as germ cell tumors, and the negatively stained gonadal tumors, serous adenomas, and cystomas. OV632 appeared useful in the distinction between negatively stained serous adenomas and positively stained serous carcinomas. In contrast, the monoclonal antibodies OC 125, OV-TL 3, OV-TL 16, and MOv 18 can be considered as pan-ovarian carcinoma markers, however without the discriminative capability as seen for OV632. These ovarian carcinoma-associated antigens were hardly found expressed in gonadal and germ cell tumors, except in the group of endodermal sinus tumors. HLA-I was found to be expressed in almost all nucleated cells, although loss of HLA-I expression was seen in areas of tumor cells. HLA-DR was negative in normal ovarian tissue, but heterogeneous expression was noticed in most of the epithelial tumors.