EFFECTS OF SEX STEROID-HORMONES ON CORTICOSTEROID-BINDING GLOBULIN GENE-EXPRESSION IN HUMAN ENDOMETRIAL CANCER CELL-LINE ISHIKAWA

The effect of progestins on intracellular corticosteroid-binding globu lin (CBG) mRNA expression in an endometrial cancer cell line (Ishikawa ) was examined in an attempt to understand the biological effects of h igh-dose progestins in the treatment of well-differentiated uterine en dometrial cancers. Oestradiol-17 beta (E2) significantly increased CBG mRNA expression in a dose-dependent manner, while a high dose of prog esterone with or without E2 suppressed it significantly. Furthermore, a high dose of progesterone or medroxyprogesterone acetate (MPA) suppr essed CBG mRNA expression to a greater degree than did chlormadinone a cetate or 17 alpha-hydroxyprogesterone caproate with or without E2. Th ese findings suggest that the effects of high-dose progestins on cance r cells may be mediated via suppression of intracellular CBG.