Effect of hyperosmotic stress on proliferation and apoptosis of hepatocellular carcinoma Huh7 cells

Abstract

Objective To investigate the effect of hyperosmotic stress on the proliferation and apoptosis of hepatocellular carcinoma Huh7 cells,and preliminarily explore the mechanism.Methods The expression of mammalian osmotic regulator nuclear factor of activated T-cells 5 (NFAT5) was detected in 64 cases of hepatocellular carcinoma by using immunohistochemistry.NaC1 was used as a chemical hyperosmotic-inducible reagent to mimic tumor hyperosmotic microenvironment.The expression of NFAT5 protein was analyzed by Western blotting.Cell apoptosis was examined by using flow cytometry and cell growth was measured by methyl-thiazol-tetrazolium (MTT) assay.Results NFAT5 positive expression rate was low (9.38％) in hepatocellular carcinoma tissue but high in the corresponding peritumoral tissue (68.75％) (P ＜0.01).Under hyperosmotic stress (100 mmol/L NaC1) for 24 h,the protein expression levels of NFAT5 in Huh7 cells were up-regulated (P ＜ 0.01).The apoptosis rate in experimental group [(26.0 ± 3.2) ％] was significantly higher than that in blank control group [(0.8 ± 0.2) ％] (P ＜0.01).Hyperosmotic stress (100 mmol/L NaCl) also inhibited growth of Huh7 cells with the cell growth inhibitory rate being (31.35 ± 2.09) ％ (P ＜ 0.01).Conclusion There are obvious differences in the expression of the only mammalian osmotic regulator NFAT5 between hepatocellular carcinoma tissue and peritumoral tissue.Hyperosmotic stress can up-regulate the NFAT5 protein expression,induce apoptosis of hepatocellular carcinoma Huh7 cells,and inhibit cells proliferation. Key words: Carcinoma, hepatocellular; Hyperosmotic stress; Apoptosis; Proliferation