Correlation study between EGFR gene mutation and radiosensitivity in non-small cell lung cancer
SUN Li-yue
ZHOU Juan
CHENG Yan-jun
ZHANG Wei-min
Abstract：Objective To investigate the correlation between the epidermal growth factor receptor (EGFR) gene mutations and radiosensitivity of non-small cell lung cancer (NSCLC) and the possible mechanism.Methods EGFR-mutant NSCLC cell lines PC-9 and H1975,and wild-type EGFR NSCLC cell line A549 were selected.The clonogenic cell survival assay was applied to determine the radiosensitivity,flow cytometry was applied to detect cell apoptosis and cell cycles distribution,and Western blot assay was applied to detect the expression of apoptotic and repair proteins.Results The radiosensitivities of both PC-9 and H1975 cells were significantly higher than that of A549 cells,and the clonogenic survivals after 4 Gy radiation were 10.0％,5.5％ and 44.3％,respectively.The apoptosis rates of PC-9 and H1975 cells at 48 h after 4 Gy radiation were significantly higher than that of A549 cells,which stood at 18.300％,17.533％ and 11.733％,respectively.The incidence of G0/G1 phase arrest in A549 cells was significantly higher than those in PC-9 and H1975 cells,and the G0/G1 phase rates at 48 h after 4 Gy radiation were 74.480％,70.293％ and 57.016％,respectively.After 4 Gy radiation,there was no expression of pro-apoptotic protein Bax in A549 cells,whereas there was still expression of the apoptotic protein Caspase-3,the anti-apoptotic protein Bcl-2 and the repair protein DNA-PKcs at 24 h.However,after 4 Gy radiation,the expression of Bax and Caspase-3 in PC-9 and H1975 cells were increased,with no expression of Bcl-2 and down-regulation of DNA-PKcs.Conclusion PC-9 cells with EGFR 19 exon deletion mutation and H1975 cells with exon 21 point mutation are more sensitive to radiation,as compared with the wild-type EGFR A549 cells.The possible mechanism is associated with G0/G1 phase arrest of cell cycles,increased Bax expression,and decreased expressions of DNA-PKcs and Bcl-2.
Keywords：non-small cell lung cancerEGFRgene mutationradiosensitivity
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 981-985 )