ESTRADIOL AND PROGESTERONE REGULATE E-CADHERIN MESSENGER-RNA LEVELS IN THE MOUSE UTERUS

E-cadherin is a calcium-dependent cell adhesion molecule which is pres ent in the epithelium of the mouse uterus. The regulators of E-cadheri n mRNA levels in this tissue have not been identified. We have examine d the ability of steroids to influence uterine E-cadherin mRNA levels in vivo. Immature mice were injected with either progesterone, testost erone, dihydrotestosterone, 17-beta estradiol or 17-alpha estradiol. P rogesterone and 17-beta estradiol caused a rapid and significant incre ase in the uterine E-cadherin mRNA levels. In contrast, testosterone, dihydrotestosterone and 17-alpha estradiol had no effect on the uterin e levels of this transcript. Actinomycin D, an inhibitor of RNA synthe sis blocked the ability of 17-beta estradiol and progesterone to stimu late E-cadherin mRNA levels. Cycloheximide, an inhibitor of protein sy nthesis had no effect on the ability of progesterone to enhance E-cadh erin mRNA levels, but this drug blocked the ability of 17-beta estradi ol to stimulate the uterine levels of this transcript. These results s uggest that 17-beta estradiol and progesterone stimulate E-cadherin mR NA levels in the immature mouse uterus by different mechanisms. We spe culate that these two steroids are key regulators of E-cadherin-mediat ed epithelial cell interactions in vivo.