The role of miR-141/ Sirt1 in colon cancer.

To explore the effects of micro ribonucleic acid-141 (miR)-141 on the proliferation and apoptosis of colon cancer cells and its association with the sirtuin 1 (Sirt1) expression. The samples of stage I, II, III and IV colon cancer were obtained, and the miRNA expression levels was analyzed, with normal colon tissues as controls. The expression of miR-141 and miR-34 was detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the cell proliferation and apoptosis in each group were detected via cell counting kit-8 (CCK8) assay, respectively. Finally, the protein expressions of Sirt1, Caspase-3 and Caspase-8 were determined using Western blotting. The expressions of miR-141 and miR-34 (miR-34 is mentioned in previous methods. Furthermore, we found the expression of miR-141 increasing with the progression of colon cancer, which was higher in stage III than in stage I-II and also higher in stage IV than in stage III. miR-34 was also highly expressed in stage IV colon cancer in our study were up-regulated in the progression of colon cancer. Overexpression of miR-141 could promote cell proliferation (p<0.05) and inhibit apoptosis (p<0.05), while inhibition on miR-141 expression could significantly weaken cell proliferation (p<0.05) and promote apoptosis (p<0.05). The results of luciferase reporter assay showed that miR-141 obviously inhibited Sirt1 (p<0.05). SRT2183 reduced cell proliferation (p<0.05) but up-regulated the protein expressions of Sirt1, Caspase-3 and Caspase-8 (p<0.05), while EX 527 had the opposite effects (p<0.05). MiR-141 may promote proliferation and reduce apoptosis of colon cancer cells via targeting Sirt1.