Tannic acid enhances cisplatin-induced apoptosis of hepatocellular carcinoma HepG2 cells by activating ATF6-CHOP pathway / 实用医学杂志

Objective To detect the activation levels of endoplasmic reticulum stress ATF6-CHOP pathway,and to investigate the molecular mechanism of tannic acid (TA) combined with cisplatin (CDDP) against hepatocellular carcinoma.Methods HepG2 cells were cultured with 180 μM TA or/and 0.9 μg/ml CDDP for 24 h or 48 h.The levels of ATF6 (ATF6α),ATF6B (ATF6β) and CHOP were analyzed by real-time fluorescence quantitative PCR (q-RT-PCR) and western blot.Results We found that after 24 h or 48 h,compared with the control group,ATF6 mRNA and protein levels,ATF6B protein level,CHOP mRNA and protein levels were significantly increased in the TA group,CDDP group or combination group (P ＜ 0.01 or P ＜ 0.05).Conclusion TA can combine with CDDP to increase the levels of endoplasmic reticulum stress ATF6-CHOP pathway,and the ATF6-CHOP pathway may be one of the molecular mechanisms synergistic anti-hepatocellular carcinoma effect of TA and CDDP on HepG2 cells.

Tannic acid enhances cisplatin effect against hepatocellular carcinoma HepG2 by endoplasmic reticulum stress pathway / 重庆医学

Objective To investigate the synergistic effects of tannic acid(TA) and cis-dichlorodiamine platinum(CDDP) on hepatocellular carcinoma HepG2 cells and its activation situation of endoplasmic reticulum stress(ERS) pathway.Methods Human hepatocellular carcinoma HepG2 cells were divided into the control group,TA group,CDDP group and TA+CDDP group,and were cultured in vitro for 24 h.The growth inhibitory effect of medication on HepG2 cells was detected by MTT assay.The pharmacodynamics synergistic effect between the two drugs was analyzed by the drug interaction index,drug dose reduction index and equivalent graphical method.The nucleus changes were observed by DAPI staining.Real time fluorescent quantitative PCR(q-RT-PCR) and Western blot were used to detect the levels of ERS markers glucose regulated protein (GRP)78 and GRP94.Results TA and CDDP had dose-dependent growth inhibition effect on HepG2 cells,their median effective concentrations(IC50) were 360.00 μmol/L and 1.80 μg/mL respectively.The combination treatment of 180.00 μmol/L TA and 0.90 μg/mL CDDP on HepG2 cells could enhance the inhibitory effect on cell growth.Ta and CDDP had synergistic effect for inhibiting hepatocellular carcinoma cells growth.Compared with the TA group and CDDP group,cell shrinkage and rounding were accelerated in the combined group,apoptotic cells were increased,nuclear had pyknosis,irregular edge and dense staining,nuclear fragmentations were increased and the expressions of GRP78 and GRP94 were up-regulated.Conclusion TA can enhance the effect of CDDP on anti-hepatic carcinoma HepG2 cells,and the synergy mechanism may be related to the activation of ERS pathway.

Enhanced activation of PERK-ATF4 pathway by Brefeldin A and cisplatin in human lung cancer GLC-82 ;cells / 实用医学杂志

Objective To investigate the molecular mechanisms of synergistic effects of BFA and CDDP on human lung cancer GLC-82 cells, and to test the levels of PERK-ATF4 pathway. Methods GLC-82 cells were incubated with 50 ng/mL of BFA or/and 2 μg/mL of CDDP for 24 or 48 hours. The levels of PERK, p-PERK and ATF4 in GLC-82 were analyzed by real-time PCRand/or Western Blot. Results The levels of PERK were lowest in CDDP group, but higher in BFA group (P < 0.05), the highest in group of BFA+CDDP (P < 0.05 or P < 0.01). The p-PERK level decreased in group of BFA+CDDP (P < 0.05 or P < 0.01). There was no significant change of ATF4 expression in CDDP group, but ATF4 expression increased slightly in BFA group, and increased further in group of BFA+CDDP (P < 0.05 or P < 0.01)which was also higher than that in BFA group or CDDP group (P < 0.05 or P < 0.01). Conclusions The upregulated levels of PERK and ATF4 by the combination of BFA and CDDP may be one of the mechanisms of synergistic anti-cancer effect of BFA and CDDP on GLC-82 cells.