Enhancement Of Human Glioma Carcinoma Cell Line SHN-44Radiosensitivity By Gamma-hydroxybutrate

Objective To investigate the function of GHB on human glioma carcinoma cellSHG-44proliferation inhibition and radiotherapy sensitization.Methods In SHG-44cell as the research object, MTT assay assesses cell growthinhibition after incubated with GHB at various concentrations and times. To observe thenucleus changes was investigated with Hoechst33258assay. The following trialincluded a control group, GHB group, Radiotherapy group and combined group. FCManalyzes cell cycles and cell apoptosis in different groups. The radiosensitization ofgamma-hydroxybutrate was measured by clongenic assay, and the survival curve wasdescribed. Expression level of HDAC1in different groups was detected byimmumofluorescence method. RT-PCR was performed to detect the expression level ofHDAC1mRNA, ATM mRNA in each group.Result The absorption value decreased with the increase of GHB concentrationand exposure time, compared with the control group. Cell apoptosis and the proportionof G0/G1phase were increased significantly in the combination group, and theproportion of S phase was reduced. The D0，Dq, SF2values for combined group werelower than those for unpretreated ones．The SER was1.27. Chromosomes are highlyconcentrated and showed strong blue fluorescence by Hoechst33258. The HDAC1mainly localized in the nucleus. RT-PCR showed that GHB inhibited expression ofHDAC1mRNA, ATM mRNA.Conclusion Gamma-hydroxybutrate enhanced radiosensitization effect on humanglioma carcinoma cell SHG-44. The possible mechanism may be involving induce cell apoptosis, redistribution cell cycle phase, repair inhibition of sublethal damage andinhibit HDAC1,ATM m RNA expression.