Study On The Molecular Mechanism Of Increased IL-8Expression Induced By X-Ray Irradiation On Lung Cancer Cells

Objective This study was designed to investigate the changes of IL-8,IL-1?,and MCP-1levels after X-ray irradiation of lung cancer cells and their molecular mechanisms,in order to understand the effects of X-ray irradiation on cytokine production in tumor cells and its role in irradiation-related inflammation.Methods Human lung cancer cell lines A549,PC-9,H1299 and H446 were cultured in vitro,and cells were irradiated with 8 Gy(6 MV X-ray).RT-PCR and real-time quantitative RT-PCR were used to detect the m RNA expression levels of IL-8,IL-1?,and MCP-1 at different time after irradiation.The expression levels of Three cytokines in the supernatant were detected by ELISA.Western Blot was used to detect the expression levels of ERK,JNK,P38 and NF-?B proteins.After treatment with signal transduction inhibitors SB202190(P38 inhibitor)and Bay117082(NF-? B inhibitor),the changes of IL-8 in each group were detected by ELISA.Results1.IL-8,IL-1?,and MCP-1 m RNA were up-regulated in different time after irradiation of each group of lung cancer cells,with the most significant increase in IL-8,while IL-1? and MCP-1 levels were not significantly increased;2.ELISA results showed that the expression level of IL-8 protein in the supernatant of lung cancer cells significantly increased at different time after irradiation,with the most significant increase on the 4th day,while IL-1 and MCP-1levels were not significantly increase;3.Western Blot showed that the phosphorylation levels of P38 and NF-?B protein were increased after irradiation,and there were no significant changes in ERK and JNK protein;4.Compared with the control group,the expression level of IL-8 in cells treated with SB202190(P38 inhibitor)and Bay117082(NF-?B inhibitor)was significantly decreased.Conclusions1.X-ray irradiation of lung cancer cells can induce the production of IL-8;2.X-ray irradiation of lung cancer cells can activate the P38/NF-?B signaling pathway;3.The activation of the P38/NF-?B signaling pathway may be related to radiation-induced IL-8 production.