沉默信息调节因子3对肝癌细胞增殖的影响

目的探讨沉默信息调节因子3（SIRT3）对肝癌细胞增殖的影响。方法Western blotting检测SIRT3在正常肝组织、永生化
肝细胞及肝癌细胞系中的蛋白表达水平；在肝癌细胞中过表达SIRT3，台盼蓝排斥实验检测过表达SIRT3对肝癌细胞增殖的影
响，EdU标记实验检测SIRT3对肝癌细胞DNA合成的影响；在肝癌细胞中过表达SIRT3，平板集落实验检测SIRT3对肝癌细胞
集落形成能力的影响；qRT-PCR验证SIRT3的沉默效率，台盼蓝排斥实验检测SIRT3沉默对肝癌细胞增殖的影响，EdU标记实
验检测SIRT3沉默对肝癌细胞DNA合成的影响。结果SIRT3在肝癌细胞系中的蛋白水平较永生化肝细胞、正常肝组织降低；
SIRT3在肝癌细胞中成功过表达，过表达SIRT3使肝癌细胞增殖数目减少了约为51%~61%（P<0.001），使肝癌细胞DNA合成下
降了约57%（P<0.05）；过表达SIRT3抑制肝癌细胞的集落形成能力；SIRT3沉默有效，SIRT3沉默使肝癌细胞的增殖增加了约
51%~61%（P<0.01），使肝癌细胞的DNA合成能力增强了137%~149%（P<0.01）。结论SIRT3可抑制肝癌细胞的增殖。

Role of SIRT3 in regulating proliferation of hepatocellular carcinoma cells in vitro

Objective To explore the role of SIRT3 in regulating the proliferation of hepatocellular carcinoma (HCC) cells in vitro.
Methods The protein expression of SIRT3 in 2 normal liver tissues, 2 immortalized hepatocyte lines, and 3 HCC cell lines was
determined with Western blotting. SIRT3 overexpression and knockdown in HCC cells were induced by transfection with a
vector expressing SIRT3 and a siRNA construct targeting SIRT3, respectively. The efficiency of SIRT3 overexpression and
knockdown was detected by Western blot and qRT-PCR, respectively. The proliferation of the transfected HCC cells was
examined using Trypan blue exclusion assay, and the cellular DNA synthesis was tested using EdU incorporation assay. The
colony-forming ability of the cells was analyzed by colony formation assays. Results SIRT3 expression was significantly lower
in the 3 HCC cell lines than in immortalized hepatocytes and normal liver tissues. SIRT3 overexpression in HCC cells
significantly lowered the cell proliferation by 51%-61% (P<0.001), reduced cellular DNA synthesis by 57% (P<0.05), and
inhibited colony formation of the cells. SIRT3 knockdown significantly increased the proliferation of HCC cells by 51%-61% (P<
0.01) and enhanced DNA synthesis by 137%-149% (P<0.01). Conclusion SIRT3 plays a inhibitory role in regulating the
proliferation of HCC cells in vitro.