Study on effect of NFκB-p65 pathway inhibition in macrophages on cigarette smoke induced non-small cell lung cancer cell NCI-H520 cells proliferation / 肿瘤研究与临床

ABSTRACT

Objective To investigate the mechanism of cigarette smoke promotes non-small cell lung cancer (NSCLC) NCI-H520 cell line proliferation mediated by macrophages with method of blocking NFκB-p65 pathway by RNAi.Methods To co-culture NCI-H520 cells with primary macrophages or U937 cell line,the Transwell Inserts system was used in cell co-culture model.NFκB activation was confirmed by electrophoretic mobility shift assay (EMSA) and Western blot analysis.U937 cells were transfected with NFκB-p65 shRNA plasmid to abrogate the NFκB activation,by BrdU ELISA,the effect of cigarette smoke extract (CSE) promoted NCI-H520 cells proliferation were assessed,inflammatory factors TNF and IL-6 expressions were analysed by ELISA.Results Exposure of CSE enhanced NFκB-p65 nuclcus translocation and activated the NFκB pathway.CSE did not promote NCI-H520 cells proliferation alone (P ＞ 0.05),but after 4 days coincubation with macrophages,the proliferation of NCI-H520 cells was significantly increased (P ＜0.01),addition of CSE to the co-culture much more enhanced this effect (P ＜ 0.01).After NFκB-p65 was blocked by RNAi,it significantly reduced NFκB-p65 protein expression and inhibited NFκB activation in U937 p65-cells,and markedly inhibited U937 cells induced proliferation of NCI-H520 cells and IL-6,TNF secretion (P ＜ 0.01).Conclusion Cigarette smoke promotes NCI-H520 cells proliferation mediated by macrophages.Blockade of NFκB pathway with RNAi in macrophages can reduced cigarette smoke induced inflammatory factors secretion in macrophages,and significantly inhibit cigarette smoke promoted tumor proliferation.