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 the levels of c-fos and c-jun expressions in uterine endometrial fibroblasts were increased and reached peak levels with the administration of estradiol, but were partially diminished by the addition of progesterone. The response of c-fos was earlier than that of c-jun. Twelve-0-tetradecanoylphorbol-13-acetate (TPA) increased c-fos and c-jun expressions in endometrial fibroblasts as estradiol did, and pretreatment with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) reduced the estrogen-inducible c-fos and c-jun expressions. Therefore, it is suggested that oncogenes c-fos and c-jun in uterine stromal cells might be induced by estrogen partly via PKC, involving the interplay of the anti-estrogenic effect of progesterone, and there might be a cross talk between estrogen and PKC stimulants for c-fos and c-jun expressions.