Fig. 4.

miRNAs promote resistance to erlotinib and other EGFR-is. A) EKVX-pmiR or B) H322M-pmiR cells were co-transfected with 6 nM premiRcontrol (indicated in dark grey) or 6 nM of the indicated miRNAs and 0.6 nM siLUC2. The positive controls, miR-4749 and miR-219 were also included, indicated in red and blue respectively. Twenty-four hours post-transfection, cells were exposed to either GI75 erlotinib, GI75 afatinib, or GI75 gefitinib, or equivalent amount of DMSO (negative control). Seventy-two hours post-treatment, reporter activity was measured. Fold change in growth of transfected cells in the presence or absence of each drug is represented relative to the respective negative control (premiRcont).