Enhancement Of Gastric Carcinoma Cell Line SGC-7901Radiosensitivity By Valproic Acid

Objective: To investigate radiosensitization effect of valproic acidon gastriccarcinoma cell line SGC-7901.Methods: MTT assay was used to measure the inhibition rate of growth ofvalproic acidon on gastric carcinoma cell SGC-7901at different concentrations anddifferent time point. The radio sensitization of valproic acid on SGC-7901cells wasmeasured by clongenic assay. The apoptosis and cycle of SGC-7901cells in differentgroups were analyzed by flow cytometry (FCM). The expression of HDAC1and ATMwere detected by RT-PCR in each group.Results: After treated with valproic acid, the cell proliferation was inhibited, cellapoptosis were increased, the proportion of S phase was reduced and the proportion ofG1phase was increased. The combination group induced apoptosis on human gastriccarcinoma cell SGC-7901was significant more than the alone group.Compared with thecontrol group, cell apoptosis and the proportion of G0/G1phase were increasedsignificantly in the combination group, and the proportion of S phase was reduced thatassayed by FCM.The IC50of valproic acid treated with SGC-7901cells for24hwas19.83mmol/L, for48h was3.67mmol/L, and for72h was2.75mmol/L, the cellproliferation was inhibited significantly in a time-and dose-dependent manner. Thevalproic acid have radiosensitization on human glioma carcinoma cell line SHG-44,SER=1.31. The result of the flow cytometry showed that more apoptosis ratio increasedand the proportion of S phase was reduced and the proportion of G0/G1phase wasincreased significantly in the combination group when comparing with the controlgroup. Valproic acid combine with radiation inhibited expression of HDAC1and ATM.Conclusion: Valproic acid can increase the radiosensitization of SGC-7901, Itsrole may be change cell cycle phase redistribution, induce cell apoptosis, and suppress the expression of HDAC1mRNA及ATM mRNA.