Abstract: Objective To investigate miR-146a expression in colonic cancer and its clinical implications. Methods Quantitative
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.
Results Compared 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. Conclusion miR-146a may serve as a potential therapeutic target for colonic cancer for its role in inhibiting
colonic cancer cell proliferation.