X-ray ionizing radiation up-regulates c-Myc expression and promotes epithelial-mesenchymal transition in lung cancer cell line A549 / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effect of ionizing radiation on epithelial-mesenchymal transition in lung cancer cell line A549 and its possible mechanism.METHODS:The lung cancer A549 cells were irradiated with different doses (0 Gy, 1 Gy, 2 Gy, 4 Gy and 8 Gy) of X-ray for different time.The morphological changes of the cells were observed under inverted microscope at time points of 12 h, 24 h and 48 h.The expression of vimentin, N-cadherin, E-cadherin and transcription factor c-Myc was detected by Western blot at the time points of 12 h and 24 h.RESULTS:After ionizing radiation, the contours of the A549 cells were unclear, the protrusions increased, and the edges were irregular, with fried egg-like collapses.The mesenchymal morphology of the A549 cells was most obvious after irradiation at 8 Gy for 48 h.Compared with 0 Gy irradiation group, the expression of vimentin was down-regulated seemingly 12 h after irradiation, but up-regulated in 2 Gy, 4 Gy and 8 Gy irradiation groups for 24 h, and the most obvious effect was observed in 2 Gy irradiation group (P<0.01).Compared with 0 Gy irradiation group, the expression of N-cadherin was up-regulated in 1 Gy, 2 Gy and 4 Gy irradiation groups for 24 h (P<0.05), while the expression of E-cadherin was not influenced.The up-regulation of vimentin expression in lung cancer cell line A549 was positively correlated with c-Myc expression.CONCLUSION:Ionizing radiation may promotes epithelial-mesenchymal transition in the lung cancer cell line A549 by up-regulating the c-Myc expression.