SIRT1 and neoplasm: SIRT1 is a member of the SIRT family of class III histone deacetylases and widely involved in the regulation of cellular senescence (Haigis and Sinclair, 2010; Morris, 2013), suggesting that miR-34a’s anti-tumor mechanisms in ECa-109 cells are executed via SIRT1 and its downstream p53/p21 pathway.