The Influence of β-elemene Combined with Radiotherapy on the Expression of DNA-PKcs mRNA and Apoptosis

Objective To explore the mechanism of radiosensitization of β-elemene to lung cell line of A549 from influcing the expression of DNA-PKcs mRNA and apoptosis.Methods Objective To explore the mechanism of radiosensitization of β-elemene to lung cell line of A549 from influcing the expression of DNA-PKcs mRNA and apoptosis.Methods The cells were devided into control group,radiotherapy group(4 Gy radiation),drug group(10 μg/ml、20 μg/mlβ-elemene )and drug with radiotherapy group (10 μg/ml、20 μg/ml β-elemene combined with 4 Gy radiation).IC50 was detected by MTT method and cell survival rate was detected by colony formation test.Cell cycle and apoptosis were analyzed with flow cytometry.The expression level of DNA-PKcs mRNA was detected by Reverse Transcription-Polymerase Chain Reaction (RT-PCR).Results MTT assay showed that IC50 values of A549 cell was 120 μg/ml.Colony formation test showed that the radiosensitivity of A549 cells could be enhanced by β-elemene.The flow cytometry confirmed that the ratio of G2/M and apoptosis were significantly increased than control group under the effect of β-elemene.The expression level of DNA-PKcs mRNA of 10 μg/ml、20 μg/ml β-elemene with radiotherapy group was declined significantly than those of the control group (P0.05).Conclusion The radiosensitization effect of β-elemene to A549 cell is associated with inducing cell apoptosis and down-regulating the expression level of DNA-PKcs mRNA