Effect of sirtuin 6 on proliferation of hepatocellular carcinoma cells

AIM: To illuminate the effect of sirtuin 6 (SIRT6) on the proliferation of hepatocellular carcinoma (HCC) cells. METHODS: The mRNA expression of SIRT6 in the peripheral blood from 200 cases of HCC patients and 50 cases of healthy people was detected by real-time quantitative PCR (RT-qPCR). The mRNA expression levels of SIRT6 in the peripheral blood from 200 cases of HCC patients were combined with multiple clinicopathologic parameters for statistical analysis. The protein expression of SIRT6 in primary hepatocytes, immortalized hepatocytes and 4 hepatoma cell lines were determined by Western blotting. The silencing of SIRT6 was conducted by transfection of vector expressing short hairpin RNA targeting on SIRT6, and the protein level of SIRT6 was measured by Western blotting. The viability of HCC cells was tested by MTS assay. DNA synthesis was analyzed by Cell-Light^TM EdU Apollo® 488 In Vitro Imaging Kit. The abilities of colony formation and anchorage-dependent growth were measured by colony formation assay and soft agar assay, respectively. RESULTS: The mRNA expression of SIRT6 in the peripheral blood of HCC patients was significantly higher than that in the healthy people, and its expression was highly associated with tumor size, tumor grade and vascular invasion. SIRT6 expression in 4 hepatoma cell lines was significantly higher than that in the others. SIRT6 silencing led to a significant decrease in the cell viability as tested by MTS assay. EdU staining revealed that SIRT6 silencing reduced DNA synthesis. SIRT6 silencing reduced the ability of colony formation and anchorage-dependent growth as determined by colony formation assay and soft agar assay, respectively. CONCLUSION: Sirtuin 6 promotes the proliferation and malignant transformation of HCC cells.