Let-7a inhibits proliferation and induces apoptosis by targeting EZH2 in nasopharyngeal carcinoma cells

Let-7a is frequently downregulated in various types of human cancer including nasopharyngeal carcinoma. However, the underlying mechanism of let-7a action in nasopharyngeal carcinoma remains elusive. In this study, we show that the enhancer of zeste homolog 2 (EZH2) is a direct target of let-7a in human nasopharyngeal carcinoma cells. The inhibition of EZH2 in vitro by let-7a, EZH2 si RNA, attenuated nasopharyngeal carcinoma cell growth, inhibited cell proliferation and induced cell apoptosis. In addition, for each biological process we identified ontology-associated transcripts that significantly correlate with EZH2 expression. Finally, the expression of EZH2 significantly abrogated let-7a-mediated cell proliferation and apoptosis in the nasopharyngeal carcinoma cells. Taken together, our results suggest that let-7a and EZH2 may be potential therapeutic targets for nasopharyngeal carcinoma.