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 hormone (GnRH) receptor-bearing tumors undergo the apoptosis with GnRH analogs. 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 expression prior to analyses. Fas was characterized by immunoblotting of membrane proteins with the specific antibodies. Fas messenger ribonucleic acid (mRNA) was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized according to the published Fas sequence.

Results: Immunoreactive Fas and Fas mRNA were detected in a high proportion (94.4%) of the specimens from endometrial carcinomas (8 of 9), ovarian carcinomas (7 of 7), and uterine leiomyosarcomas (2 of 2); all these expressed GnRH receptor. There was neither substantial Fas nor GnRH receptor in 9 cervical carcinomas. Cloned cell lines gave identical results to those obtained in their respective mother tumors.

Conclusion: These data might suggest the frequent expression of Fas in the GnRH receptor-bearing tumors, but not in the GnRH receptor-negative tumors. Despite a poorly understood processes of apoptosis at present, there may be at least some similarity in signal transduction pathway utilized by GnRH analogs and Fas ligands.