The effect of c-IAP1 on radiosensitivty of lung cancer cells

Abstract

Objective To investigate the correlation between the level of apoptosis protein 1 (c-IAP1) and the radiosensitivity of lung cancer cells. Method The survival rate and proliferation of the lung cancer cells lines (A549, H460, H1299, H358, HCC827, H1650) from six human were detected by thiazolyl blue tetrazolium bromide (MTT) and cell colony formation assay. The DNA damage effects of radiation on lung cancer cells were detected by comet assay. The expressions of c-IAP1 protein and its mRNA were determined by Western blot and real-time quantitative PCR. Results The results of MTT and colony formation showed that the radiosensitivity of different lung cancer cells was also different, among which H358 and H460 cells had the highest radiosensitivity than that of H1650 and HCC827 cells, and H1299 and A549 cells had the weakest radiosensitivity. The results of comet assay showed that six kinds of lung cancer cells were suffered by DNA damage after radiation, and the DNA damage of H358 cells was most serious. The results of Western blot and real-time quantitative PCR showed that the c-IAP1 protein level was negatively correlated with the radiosensitivity of lung cancer cells. The higher the c-IAP1 protein level, the weaker the radiosensitivity of cells. The radiosensitivity was also affected by Smac protein levels. Conclusions c-IAP1 may be a selective target gene in mediating the radiosensitivity of lung cancer cells and this paper may contribute to the study of radioresistance and radiosensitization of cancer cell. Key words: Cellular inhibitor of apoptosis protein 1; Radiosensitivity; Lung cancer cells; γ-ray