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A study of radiosensitizing effect of PKM2 silencing in lung adenocarcinoma cells and xenografts
Wang Huanhuan, Zeng Xianliang,Meng Maobin, Qian Dong,Ying Guoguang, Zhao Lujun, Yuan Zhiyong, Wang Ping
Department of Radiation Oncology, Tianjin Medical University Cancer Institute& Hospital, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin 300060, China
Abstract Objective To investigate the impacts of pyruvate kinase M2 isoform (PKM2) silencing on the radiosensitivity of lung adenocarcinoma cell line (A549 cells) and the radiation synergy of xenografts, and to explore their mechanisms. Methods Plasmid pshRNA-PKM2 for interference with PKM2 expression was transfected into A549 cells, and empty vector-transfected cells and untransfected cells were set as controls. The silencing efficiency of pshRNA-PKM2 and the expression level of microtubule-associated protein 1 light chain 3(LC3) were measured by Western blot assay. The radiosensitizing effects in A549 cells and xenografts after PKM2 silencing were determined by colony-forming assay and xenografts growth curves. Autophagy formation in A549 cells and xenografts was analyzed by transmission electron microscopy, and the expression level of PKM2 in xenografts was measured by immunohistochemistry. Comparison between groups was made by Student′st-test, and the body weights of nude mice and xenograft volumes were subjected to analysis of variance for continuous variables. Results Stable A549 cell lines transfected with pshRNA-PKM2 were successfully produced. Transfection with pshRNA-PKM2 significantly down-regulated PKM2 expression in A549 cells and xenografts (P=0.001;P=0.000). The sensitizer enhancement ratios for A549 cells and xenografts were 1.47 and 2.00, respectively. Interference with PKM2 expression enhanced radiation-induced autophagy formation and significantly increased the ratio of LC3-II/I (P=0.0001). ConclusionsSilencing of PKM2 expression may enhance the radiosensitivity of A549 cells and xenografts by regulation of autophagy, which holds promise for becoming an effective radiosensitizing target for non-small cell lung cancer, but still needs to be confirmed by further studies.
Wang Huanhuan,Zeng Xianliang,Meng Maobin et al. A study of radiosensitizing effect of PKM2 silencing in lung adenocarcinoma cells and xenografts[J]. Chinese Journal of Radiation Oncology, 2015, 24(4): 466-470.
Wang Huanhuan,Zeng Xianliang,Meng Maobin et al. A study of radiosensitizing effect of PKM2 silencing in lung adenocarcinoma cells and xenografts[J]. Chinese Journal of Radiation Oncology, 2015, 24(4): 466-470.
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2015, Vol. 24 
