ESTROGEN-INDUCED EPITHELIAL PROLIFERATION AND CORNIFICATION ARE UNCOUPLED IN SINUS VAGINAL EPITHELIUM ASSOCIATED WITH UTERINE STROMA

Epithelium from the urogenital sinus-derived portion of the newborn mo use vagina when grown in association with uterine mesenchyme forms a ' 'vaginal'' stratified squamous non-cornified epithelium. However, the epithelium of these tissue recombinants composed of sinus vaginal epit helium plus uterine mesenchyme does not undergo the fluctuations in cy todifferentiation normally seen in vaginal epithelium during the estro us cycle (e.g., cornification and mucification). In this report we sho w that sinus vaginal epithelium in association with uterine mesenchyme proliferated in response to estradiol but failed to cornify in respon se to diethylstilbestrol (DES), even though both the epithelium and th e stroma had estrogen receptors. However, if sinus vaginal epithelium that had been grown in combination with uterine mesenchyme was re-isol ated from the tissue recombinant and recombined with fresh vaginal mes enchyme, the epithelium cornified in response to DES. These results in dicate that the proliferative and the cytodifferentiation response to estrogen could be uncoupled and that sinus vaginal epithelium required vaginal stroma to cornify in response to DES.