The Selective Expression of Ret Finger Protein in Endometrial Cancer: Can RFP be a Marker of Serous Carcinomas?

Abstract

Endometrial cancer is a common malignancy of the gynecological system and has been classified into two major groups, Types I and II. Type I tumors are estrogen-related, low-grade endometrioid tumors, whereas type II tumors are aggressive, high-grade non-endometrioid tumors. Ret finger protein is a nuclear transcription factor with a tripartite motif that is highly expressed in different tumor cells. To analyze the expression of ret finger protein in endometrial tissues and cancer, 18 cases of secretory and proliferative endometrium, endometrial polyp, endometrial hyperplasia and endometrial intraepithelial neoplasia and 21 cases of types I and II endometrial carcinoma were evaluated immunohistochemically. Although rare cases of secretory endometrium showed a weak focal nuclear positivity, remaining proliferative endometrium, endometrial hyperplasia and type I endometrioid cancer cases were negative. In contrast, all cases of serous cancers showed strong nuclear positivity. After these strong positive results for serous endometrial cancer, 12 more cases of ovarian and endometrial serous carcinoma cases were added to the study. All of the additional cases were also strongly positive for ret finger protein. We suggest that ret finger protein might play a role in the carcinogenesis of the serous tumors of gynecological system and can be used to differentiate serous carcinomas from other epithelial tumors.