OBJECTIVETo investigate miR-146a expression in colonic cancer and its clinical implications.

METHODSQuantitative real-time PCR was employed to detect the levels of miR-146a expression in colonic cancer tissues, pair-matched adjacent normal tissues and different colonic cancer cell lines. MTT essay was used to evaluate the proliferation of colonic cancer SW260 cells transfected with miR-146a mimics, and the cell cycle and apoptosis of the cells were analyzed with flow cytometry.

RESULTSCompared with the normal tissues, 38 of the 43 colonic cancer samples showed down-regulated miR-146a expression, which was associated with poor tumor differentiation. The expression of miR-146a in the tumor tissues was significantly correlated with tumor size and clinical stages. The patients with high miR-146a expression levels had significantly longer total survival time than those with low expression of miR-146a. In SW260 cell cultures, transfection with miR-146a mimics significantly inhibited cell growth (P<0.05) and increased the cell apoptosis rate (11.9% vs 5.9%) but produced no obvious effect on cell cycle.

CONCLUSIONSmiR-146a may serve as a potential therapeutic target for colonic cancer for its role in inhibiting colonic cancer cell proliferation.