COCULTIVATION OF OVARIAN-CARCINOMA CELLS WITH DERMAL FIBROBLASTS INDUCES FIBROBLAST EXPRESSION OF SEX STEROID-RECEPTOR TRANSCRIPTS AND PROTEIN

We have previously reported that stromal fibroblasts of ovarian carcin oma specimens may express estrogen (ER) and progesterone receptors (PR ) when the malignant epithelial cells do not, and even when the specim ens have been obtained from such non-Mullerian structures as the oment um whose fibroblasts normally express neither ER nor PR. in an attempt to investigate whether our observations of the expression of ER and P R in fibroblasts surrounding metastatic invasive epithelial ovarian ca rcinoma cells might result from an interaction involving malignant epi thelial cells and stromal fibroblasts, we cocultivated in vitro BG1 ov arian carcinoma cells with sex steroid receptor-negative dermal fibrob lasts to determine whether carcinoma cells might induce the latter to express ER or PR protein and transcripts at levels detectable by stand ard immunocytochemical (ICC) and in situ hybridization (ISH) technique s. We report the in vitro induction of ER and PR transcripts and prote in in previously steroid receptor-negative skin fibroblasts after co-c ultivation with BG1 ovarian adenocarcinoma cells; Such observations su ggest that a juxtacrine mechanism is responsible for the observed phen omenon, possibly involving ER- and PR-inducing factors (PR-IF and PR-I F).