ESTROGEN INDUCTION OF INSULIN-LIKE GROWTH-FACTORS AND MYC PROTOONCOGENE EXPRESSION IN THE UTERUS

In contrast to the effects observed in vivo, isolated uterine cells cultured in vitro demonstrate little proliferative response to estrogens. Estrogen induced uterine proliferation involves a carefully orchestrated, sequential activation of genes which encode a variety of biologically active molecules. These include nuclear transcription factors, growth factors and growth factor receptors. Expression of these proteins serve to amplify the effect of estrogen through cellular, autocrine and paracrine mechanisms. In this review the effects of estrogen on uterine expression of the myc family of oncogenes and the insulin-like growth factors are discussed.