IL-8 Confers Acquired Resistance to EGFR Inhibitors through Regulating Stem Cell-like Properties in Lung Cancer

Previous study has demonstrated that PC9/gef cells are resistant to gefitinib-induced aspoptosis. To investigate the regulators contributed to gefitinib resistance in lung cancer, we analyzed the gene expression profiles between PC9 and PC9/gef cells. Our results showed that IL-8 contributes to gefitinib resistance and cancer stemness. In contrast, IL-8 knockdown decreased stem-like characteristics and increased gefitinib-induced apoptosis in PC9/gef cells. RNAs extracted from gefitinib-sensitive PC9 cells and gefitinib-resistant PC9/gef cells were hybridized on Affymetrix microarrays. We tried to compare the differential gene expression profiles between PC9 and PC9/gef cells to identify the possible regulators in gefitinib resistance.