ABSTRACT
OBJECTIVE: To investigate the effect of nickel sulfate on cell survival rate and apoptosis of normal human liver L02 cells. METHODS: i) L02 cells in logarithmic growth phase were divided into 9 groups, each with 6 wells. L02 cells in each group were treated with 0, 100, 200, 300, 400, 500, 600, 700 and 800 μmol/L nickel sulfate. The survival rate of L02 cells was determined by CCK-8 assay after cells were treated for 0, 6, 12, 24, 48 and 72 hours. The nickel sulfate exposure dose and exposure time for subsequent experiments were selected based on the results of CCK-8 assay. ii) L02 cells in logarithmic growth phase were divided into control group, 100 and 300 μmol/L dose groups, and were exposed to 0, 100 and 300 μmol/L nickel sulfate for 12 hours, respectively. Western blot was used to detect the relative protein expression of B cell lymphoma/leukemia 2(BCL-2), Bcl-2 related protein X(BAX), caspase-3, phosphorylated RNA-dependent protein kinase-like endoplasmic reticulum kinase(p-PERK), phosphorylated eukaryotic translation initiation factor 2α(p-eIF2α), CCAAT/enhancer-binding protein homologous protein(CHOP) and glucose regulatory protein 78(GRP78). RESULTS: i) After treatment with nickel sulfate, the survival rate of cells decreased with the increase of dose and the prolongation of exposure time(all P values were <0.01). According to the half inhibitory concentration of nickel sulfate on L02 cells, the nickel sulfate exposure time in subsequent experiments was selected as 12 hours, and the exposure concentration was 100 and 300 μmol/L. ii) Compared with the control group, the relative expression of BCL-2 protein in L02 cells in the 100 and 300 μmol/L dose groups decreased(all P values were <0.05), while the relative protein expression of BAX, caspase-3 protein and ratio BAX/BCL-2 increased(all P values were <0.05). Compared with 100 μmol/L dose group, the relative expression of BCL-2 protein in L02 cells of 300 μmol/L dose group decreased(P<0.05), while the relative expression of BAX and caspase-3 protein and the ratio of BAX/BCL-2 increased(all P values were <0.05). Compared with the control group, the relative expression levels of p-PERK, p-eIF2α, CHOP and GRP78 protein in L02 cells were increased in 100 and 300 μmol/L dose groups(all P values were P<0.05). Compared with 100 μmol/L dose group, the relative expression levels of p-eIF2α, CHOP and GRP78 protein in 300 μmol/L dose group were increased(all P values were<0.05).CONCLUSION: Nickel sulfate can regulate the expression of apoptosis related proteins and PERK signaling pathway related proteins in L02 cells, aggravate apoptosis of L02 cells and decrease the cell survival rate.
ABSTRACT
During growth,invasion and metastasis,tumor cells undergo endoplasmic reticulum stress(ERS)under hypoxia,hy-poglycemia and other environmental stresses.In response to ERS,tumor cells induce unfolded protein response(UPR).PERK signa-ling pathway as a key pathway to activate UPR can promote survival,proliferation,invasion and protection of tumor cells by increasing tumor tolerance to adverse microenvironment,inducting angiogenesis,inducing autophagosome formation and activating apoptotic signal molecules.Tumor cells are induced apoptotic and autophagic death when UPR reaches a certain extent.