Role of Autophagy in the Radiosensitivity of Human Lung Adenocarcinoma A549 Cells

Radiotherapy is an important treatment for lung cancer. The poor prognosis of lung cancer is largely caused by the high recurrence rate and metastasis of the tumor. Autophagy, which can be induced by radiotherapy, might be associated with DNA repair. The aim of this study is to investigate whether activating autophagy using rapamycin can enhance the radiosensitivity of lung cancer cells and clarify the association of autophagy with DNA repair.The human adenocarcinoma A549 cell line was selected as the experimental subject. The specimens were divided into three groups: control (N), radiation (R), and Rapamycin and radiation (R+RAPA). The protein levels of γ-H2AX, Rad51, Ku70/Ku80, p62, and LC3 were determined by Western blot. Autophagosome was observed under a transmission electron microscope, and SF was determined by colony formation assay.Compared with group R, the activity of autophagy and the protein expression levels of Rad51 and Ku70/80 were remarkably increased in group R+RAPA.The radiosensitivity of lung cancer can be promoted by activating autophagy via treatment with Rapamycin, and the process may be associated with DNA repair. .