Human endometrial cytodifferentiation by histone deacetylase inhibitors

Abstract Human uterine endometrium repeats proliferation, differentiation (decidualization) and tissue breakdown during the menstrual period. Appropriate secretion of ovarian steroid hormones regulates these sequential endometrial remodeling cycles. While progesterone replacement therapy is adopted for endometrial dysfunction of differentiation, including recurrent impairment of implantation, no obvious effective results are obtained. Histone reversible acetylation, regulated by histone acetyltransferases and histone deacetylases plays a pivotal role in gene transcription. Although, in cells cultured with histone deacetylase inhibitors (HDACI), the expression of only about 2% of expressed genes is changed twofold or more compared with untreated control cells. Numerous previous works have demonstrated that HDACI affect cell proliferation/apoptosis in a variety of types of cells. To date, several HDACI are in phase I or phase II clinical trials as anticancer drugs. However, no reports have been found that HDACI is useful for transdifferentiation in human endometrium. Recently, we reported that HDACI could induce the expression of differentiation marker proteins, morphological change and functional cytodifferentiation in both human endometrial stromal and epithelial cells. In this review, we summarize the effect of HDACI against the human endometrial cytodifferentiation, indicating the possibility that HDACI can be used not only as an anticancer drug, but also as a transdifferentiation reagent, based on a new strategy.