DNMT Inhibitors and HDAC Inhibitors Regulate E-Cadherin and Bcl-2 Expression in Endometrial Carcinoma in vitro and in vivo

<i>Background:</i> The effect of histone deacetylase inhibitors (HDACIs) and DNA methyltransferase inhibitors (DNMTIs) on proliferation of endometrial cancer (EC) cells in vitro and in vivo was investigated. <i>Methods:</i> Changes in methylation of the CDH1 promoter in HDACI- and DNMTI-treated HEC-1-B and RL-952 EC cells were detected. Nude mice with xenografted implants of human EC HEC-1-B cells were treated with valproic acid (VPA) and decitabine (DAC) and evaluated for tumor growth, CDH1 and Bcl-2 mRNA levels. <i>Results:</i> DAC, VPA and suberoylanilide hydroxamic acid (SAHA) inhibited proliferation, induced cell cycle arrest and enhanced the apoptotic index in both cell lines, DAC, VPA and SAHA upregulated E-cadherin mRNA and protein levels and downregulated Bcl-2 mRNA levels in vitro. DAC and VPA inhibited tumor growth, upregulated CDH1 mRNA and downregulated Bcl-2 mRNA levels in vivo. <i>Conclusions:</i> A combination of HDACIs and DNMTIs suppresses the growth of EC, which is likely mediated by upregulation of E-cadherin and downregulation of Bcl-2.