Objective To determine the effect of apurinic/apyrimidinic endonuclease-1(APE1) on the radiosensitivity of non-small cell lung cancer cells. Methods The expression of APE1 was detected by immunohistochemistry in 20 surgical specimen of non-small cell lung cancer tissues and 5 cases of pericarcinous lung tissues.The expressions of APE1 protein and mRNA in non-small cell lung cancer cell lines(A549,H460,H1299)and normal lung epithelial cell lines was detected by Western blot and qRT-PCR. The A549 and H460 stable cell lines with silencing of APE1 were constructed.The expression of APE1 in the silenced and non-silenced cells after exposure to 0-6 Gy radiation was detected by Western blot. The effect of silencing of APE1 was measured by colony formation assay,the proliferation of non-small cell lung cancer cells detected by CCK-8 assay, and the apoptosis of non-small cell lung cancer cells detected by Annexin Ⅴ/PI flow cytometry.Results The expression of APE1 was upregulated in non-small cell lung cancer tissues and cell lines.Radiation induced the expression of APE1 in non-small cell lung cancer cells in a dose responsive way. The silencing of APE1 inhibited the expression of APE1 induced by radiation in A549 and H460 cells. Exposure to radiation of the cells with silenced APE1 further inhibited cell colony formation and cell proliferation, and promoted the apoptosis of non-small cell lung cancer cells ( P＜0.05). Conclusion Silencing of APE1 enhances the radiosensitivity of non-small cell lung cancer cells.
