Integrin beta 1 enhances the epithelial-mesenchymal transition in association with gefitinib resistance of non-small cell lung cancer

We have previously shown that integrin beta 1 associates with gefitinib resistance. As epithelial-mesenchymal transition (EMT) also induces gefitinib resistance in vitro, we wished to determine the relation of them in gefitinib resistance. In this study, we show that integrin beta 1 induced epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) resistance in xenograft tumors and gefitinib-resistant NSCLC tumors acquired EMT phenotype. Furthermore, inhibition of integrin beta 1 reverses EMT, meanwhile overexpression and activation of integrin beta 1 aggravates EMT. Lastly, we further identified that integrin beta 1 enhanced EMT via FAK-AKT signaling pathway. These findings highlight a novel relation of integrin beta 1 and EMT in EGFR TKI resistant NSCLC.