Downregulation of myosin VI reduced cell growth and increased apoptosis in human colorectal cancer.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, with the mortality increasing steadily over the last decade. Myosin VI (MYO6) expression is found to be elevated in some types of human carcinoma cell types, suggesting that it may be a sensitive biomarker for the diagnosis and follow-up. In this study, we first used the Oncomine database to explore the expression of MYO6 in CRC tissues, and then constructed a plasmid of RNA interference targeting MYO6 gene. After transfection of lentivirus targeting MYO6 into SW1116 cells, cell viability and proliferation were measured with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assay. Cell cycle distribution was assayed by flow cytometry and apoptosis was evaluated by Annexin V. MYO6 expression was detected by quantitative real-time polymerase chain reaction and western blot analysis. It was found that MYO6 mRNA was upregulated in CRC tissues using data mining of public Oncomine microarray datasets. Depletion of MYO6 significantly inhibited cell proliferation and colony formation. In addition, knockdown of MYO6 slightly arrested cell cycle in G0/G1 phase, but remarkably increased the proportion of the sub-G1 phase of cell with the increase of apoptotic cells. These results suggest that MYO6 may promote cell growth and may be used as a potential target for anticancer therapy of CRC.