ABSTRACT
Objective To establish the insulin resistant HepG2(HepG2/IR)cells model,and investigate the relationship of insu-lin resistance and reduced susceptibility to chemotherapy in hepatoma cells and its mechanism.Methods HepG2 cells were cultured in medium containing 0.5μmol/L insulin for different hours to induce insulin resistance.Glucose consumption of HepG2/IR cells were measured by Hitachi 7600 automatic biochemical analyzer.The cis-dichlorodiamineplatinum(DDP)sensitivity of the HepG2 and HepG2/IR cells were determined by MTT assay,the Annexin Ⅴ/PI assay was adopted to measure the apoptosis rate.In addi-tion,real-time PCR,flow cytometry (FCM)and Western-Blot were employed to detect the mRNA and protein levels of insulin re-ceptor(InsR)and endoplasmic reticulum chaperonin 78(GRP78).Results The glucose consumption decreased and expression of In-sR was down-regulated in HepG2/IR cells.The HepG2/IR cells had reduced sensitivity to DDP (P<0.05 ).The IC50 s of the HepG2/IR cells treated by DDP for 48 h and 72 h were 158.8% and 165.9% of HepG2 cells respectively,while the apoptosis rate was 50.29% lower.The mRNA and protein level of GRP78 in HepG2/IR cells were 2.12 and 2.27 times of that in HepG2 cells. Conclusion The stable HepG2/IR cells showed stronger resistance to DDP were established from HepG2 cell induced with insulin, and its mechanism may be related to the increased expression of GRP78.