MicroRNA-7 enhances cytotoxicity induced by gefitinib in non-small cell lung cancer via inhibiting the EGFR and IGF1R signalling pathways

Gefitinib is a tyrosine kinase inhibitor that has been used for the treatment of non-small-cell lung carcinoma (NSCLC). The ability of miR-7 to enhance gefitinib-induced cytotoxicity in NSCLC cells was evaluated in this study. We found that miR-7 significantly decreased the IC50 of gefitinib and inhibited cell growth. G0/G1 cell cycle arrest and cell apoptosis were increased after the treatment of gefitinib coupled with miR-7 transfection. In addition, levels of Raf1, IGF1R, and PI3K and phosphorylation levels of Akt and ERK were also significantly decreased. Our results suggest that miR-7 may provide a novel therapeutic target for the treatment of NSCLCs.