EZH2 is over-expressed in human colon cancer and is closely associated with tumor proliferation, metastasis and poor prognosis. Targeting and inhibiting EZH2 may be an effective therapeutic strategy for colon cancer. 3-Deazaneplanocin A (DZNep), as an EZH2 inhibitor, can suppress cancer cell growth. However, the anti-cancer role of DZNep in colon cancer cells has been rarely studied. In this study, we demonstrate that DZNep can inhibit the growth and survival of colon cancer HCT116 cells by inducing cellular senescence and apoptosis. The study provides a novel view of anti-cancer mechanisms of DZNep in human colon cancer cells.