FREQUENT EXPRESSION OF FAS IN GONADOTROPIN-RELEASING-HORMONE RECEPTOR-BEARING TUMORS

Objective: Fas, a cell surface receptor, mediates cell death by means of apoptosis in a variety of cell types. Gonadotropin-releasing hormon e (GnRH) receptor-bearing tumors undergo the apoptosis with GnRH analo gs. The authors attempted to determine the frequency with which Fas is present in the GnRH receptor-bearing tumors. Study Design: Surgically removed gynecological tumors were screened for GnRH receptor expressi on prior to analyses. Fas was characterized by immunoblotting of membr ane proteins with the specific antibodies. Fas messenger ribonucleic a cid (mRNA) was determined by reverse transcription-polymerase chain re action using oligonucleotide primers synthesized according to the publ ished Fas sequence. Results: Immunoreactive Fas and Fas mRNA were dete cted in a high proportion (94.4%) of the specimens from endometrial ca rcinomas (8 of 9), ovarian carcinomas (7 of 7), and uterine leiomyosar comas (2 of 2); all these expressed GnRH receptor. There was neither s ubstantial Fas nor GnRH receptor in 9 cervical carcinomas. Cloned cell lines gave identical results to those obtained in their respective mo ther tumors. Conclusion: These data might suggest the frequent express ion of Fas in the GnRH receptor-bearing tumors, but not in the GnRH re ceptor-negative tumors. Despite a poorly understood processes of apopt osis at present, there may be at least some similarity in signal trans duction pathway utilized by GnRH analogs and Fas ligands. (C) 1997 Els evier Science Ireland Ltd.