Fig. 1

Elevated miR-762 expression is associated with gefitinib resistance in NSCLC cells. a RT-qPCR analysis of miR-762 expression in different NSCLC cells. Relative expression levels of miR-762 were obtained in each sample by normalization of the expressions of miR-762 to that of the U6 snRNA signal. For presentation of data, expression levels of miR-762 from NuLi-1 cells were taken as 100% and the others were normalized accordingly. Each value is a mean ± S.E.M. from three independent experiments. Different superscript letters denote groups that are statistically different (P < 0.05). b The IC50 value (inhibitory concentration to produce 50% cell death) following a 48-h exposure to gefitinib was determined in PC-9 and PC-9/GR cells using MTT assay. c The IC50 value following a 48-h exposure to gefitinib was determined in A549 and A549/GR cells using MTT assay. d-e Characterization of miR-762 expression in different NSCLC cells using RT-qPCR. The value indicates the relative expression levels of miR-762 in the cells (PC-9/PC-9/GR and A549/A549/GR cells) at different batches of gefitinib resistant induction