Trichostatin A Increases Radiosensitivity of Non-small Cell Lung Cancer A549 Cells

Objective:To investigate the activity of trichostatin A(TSA),one of the HDIs,on radiosensitize human non-small cell lung cancer(NSCLC) cell line A549 cells in vitro.Methods:A549 cells were exposed toγ-irradiation with or without TSA pre-treatment. MTT assay was performed to detect cell viability.Apoptosis was analyzed with Annexin V-PI staining by flow cytometry.The pro-apoptotic protein Bax expression in cytoplasm and mitochondria was detected by western blot.The changes of mitochondrial membrane potential(MMP) were measured by flow cytometry.Results:The pre-treatment with TSA 0.5μM radiosensitized A549 cells toγ-irradiation(5Gy) significantly by decreasing cell viability.γ-irradiation or TSA alone only caused small amount of apoptotic cells,as indicated by Annexin V positive cells.However,TSA pre-treatment enhancedγ-irradiation-induced apoptosis significantly.In the combined treatment group,mitochondrial Bax expression was higher than that in the other groups,and which decreased MMP significantly compared withγ-irradiation(5Gy) or TSA alone.Conclusions:TSA has potential to act as radio-sensitizer in A549 cells through Bax activation and mitochondrial apoptotic pathway.