Research About Effect On HepG2Cell And Mechanism Of Anacardic Acid

ObjectiveThe research focus on the toxic effect on tumor cells especially hepatocellularcarcinoma with AA only or the combination of AA and other anti-tumordrugs,simultaneously,approaching the molecular mechanism of the function ofAA.Through the research,to help make AA as an inhibitor of tumor in clinic.MethodsFirst of all,the cytotoxic effects on HepG2cells with AA, Doxorubicin (destructivereagent of DNA),Nocodazole(destructive reagent of microtubule) can be detected withthe method of MTT respectively.Set ten different concentrations with the span of2times for each drug.Half inhibition rate(IC50) can be calculated for each kind of drugson HepG2cell.Then compare the cytotoxic effects with Doxorubicin and the cytotoxiceffects with the combination of Doxorubicin and Ancardic Acid in the sameconditions,and make the same comparison between Nocodazole only and thecombination of Nocodazole and Ancardic Acid.A cobalt-60γ-ray source was used toirradiate the cells of control group at a dose rate of1.67Gy/min at roomtemperature.Ancardic acid was added in the culture media before the irradiation for thecells of experimental group, and other condition were kept the same with the controlgroup. After irradiation, the cells were harvested either immediately or at an indicatedtime of postirradiation culture and then subjected to further experiments.The changes ofproteinγ-H2AX related with cell apoptosis and the proteins in the DNA-PKcs/Akt/GSK-3β signaling pathway through analysis of Western blot.ResultsThe results show that the inhibitive effect of AA on tumor cells is notobvious.However,AA can apparently enhance the inhibition on tumor cells growth ofDoxorubicin and Nocodazole.From the analysis of Western blot,the intervention of AA inhibited the phosphorylation of DNA-PKcs、Akt and GSK-3β,thus the injure on thecell lines from irradiation of cobalt-60can be larger because the self-recovery functionthrough the DNA-PKcs/Akt/GSK-3signaling pathway has been delayed. Incontrast,the control group with the absence of AA can repair throughDNA-PKcs/Akt/GSK-3signaling pathway to decrease the injure.γ-H2AX isconsidered to be an injury marker which can reflect the degree of injury caused byirradiation of cobalt-60.ConclusionsAA itself show little inhibition effect on tumor cells,however,it can significantlyenhance the inhibition of DNA damaging reagent and microtubule danmagingreagent.AA functions as a inhibition of protein phosphorylation through the theinfluence of DNA-PKcs-Akt-GSK-3signaling pathways,thereby aggravating thedamage to the cell.