ESTROGEN INDUCES THE EXPRESSION OF C-FOS AND C-JUN GENES IN FIBROBLASTS DERIVED FROM HUMAN UTERINE ENDOMETRIUM

The ratio of membrane/cytosolic protein kinase C (PKC) activity and th e levels of c-fos and c-jun expressions in uterine endometrial fibrobl asts were increased and reached peak levels with the administration of estradiol, but were partially diminished by the addition of progester one. The response of c-fos was earlier than that of c-jun. Twelve-O-te tradecanoylphorbol-13-acetate (TPA) increased c-fos and c-jun expressi ons in endometrial fibroblasts as estradiol did; and pretreatment with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) r educed the estrogen-inducible c-fos and c-jun expressions. Therefore, it is suggested that oncogenes c-fos and c-jun in uterine stromal cell s might be induced by estrogen partly via PKC, involving the interplay of the anti-estrogenic effect of progesterone, and there might be a c ross talk between estrogen and PKC stimulants for c-fos and c-jun expr essions.