Objective We performed this study to explore the effect of NCLX-mediated mitochondrial calcium on the growth of hep-atocellular carcinoma （HCC） cell line. Methods Eukaryotic expression vector pSliencer3.0-shNCLX and pcDNA3.1（+）-NCLX were transfected into HCC cells SNU-739 and SNU-368，respectively，and NCLX was stably knocked down or overexpressed. The expression level of NCLX protein was detected by Western blot assay. Rhod-2-AM staining was used to detect the level of mitochondrial calcium. The proliferation ability of cells was evaluated by MTS and EdU assay. The apoptosis of cells was assessed by apoptosis assay. Results Western blot assay showed that NCLX was stably knocked down or overexpressed in HCC cells SNU-739 and SNU-368. Compared with transfected empty vector，the mitochondrial calcium level was significantly increased after downregulation of NCLX expression （P<0.01），the cell proliferation rate was significantly increased （P<0.05），and the apoptosis rate was significantly decreased （P<0.01） in HCC cells SNU-739 and SNU-368. After upregulation of NCLX expression，the mitochondrial calcium level was significantly decreased （P<0.05），the cell proliferation rate was significantly decreased （P<0.05），and the apoptosis rate was significantly increased （P<0.01） in HCC cells SNU-739 and SNU-368. Conclusions In HCC cells，downregulation of NCLX-induced increase in mitochondrial calcium level may effectively promote cell proliferation and inhibit apoptosis. However，overexpression of NCLX-induced decrease in mitochondrial calcium levels inhibits cell proliferation and promotes apoptosis in HCC cells SNU-739 and SNU-368.These results suggest that NCLX may be a potential target for the treatment of hepatocellular carcinoma.
