miR-29c overexpression sensitizes resistant GBM cells to TMZ in vitro. (A) Colony formation ability of the miR-NC- or miR-29c-infected U251/TMZ-R or U87/TMZ-R cells without transfection or transfected with pcDNA3.1-REV3L in the absence or presence of TMZ. The results of three independent experiments are shown. **P < 0.01. (B) The apoptotic rates of U251/TMZ-R or U87/TMZ-R cells transduced with miR-NC, miR-29c or miR-29c plus REV3L upon treatment with TMZ (200 μM) for 48 h were measured by flow cytometry. Columns are the average of three independent experiments. **P < 0.01. (C) Western blot analysis showing levels of pro-caspase-3, cleaved caspase-3, pro-caspase-7, cleaved caspase-7 in the miR-NC, miR-29c or miR-29c plus REV3L-transduced U251/TMZ-R or U87/TMZ-R cells after TMZ treatment. β-actin served as the internal control. (D) TUNEL analysis of miR-NC, miR-29c or miR-29c plus REV3L-transfected U251/TMZ-R cells treated with TMZ for 48 h. Data are means of three independent experiments ± SD. Scale bar = 200 µm. (E) qRT-PCR analysis of miR-29c in A172 cells after inhibition of miR-29c. U6 RNA served as the loading control. **P < 0.01. (F) Colony formation assay performed in A172 cells transduced with control inhibitor or antisense miR-29c or antisense miR-29c plus shREV3L in the absence or presence of TMZ. The results of three independent experiments are shown. **P < 0.01. (G) Flow cytometry analysis in A172 cells transduced with control inhibitor or antisense miR-29c or antisense miR-29c plus shREV3L after TMZ treatment. Apoptosis results of three independent experiments are shown. **P < 0.01.