Fig. 4: MiR-421-KEAP1 mediates drug resistance to paclitaxel in lung cancer.

a WB analysis of KEAP1 expression in A549 and A549T cells. b Detection of KEAP1 mRNA levels in A549 and A549T cells via real-time PCR. c Examination of endogenous miR-421 levels by real-time PCR in A549 and A549T cells. d Cell viability was measured in A549 and miR-421 overexpression stable A549 cells after treatment with paclitaxel for 24 h by MTT assay. e Wound healing assays were performed in WT and miR-421 overexpression stable A549 cells after treatment with 10 nM or 50 nM paclitaxel. f, g After transfection with AMO-miR-421 for 24 h, ROS generation was detected by flow cytometry after DCFDA staining. The results are expressed as the mean ± SD of 3 independent experiments, **P < 0.01 when compared with control. h, i A549T cells or cells with AMO-421 were treated with vehicle or 200 nM paclitaxel for 24 h, and cell apoptosis was measured by Annexin V/PI double staining and flow cytometry. The data are presented as the mean ± SD. *P < 0.05. j After injection with A549 cells, mice were treated with vehicle, paclitaxel, AMO-miR-421 or paclitaxel combined with AMO-miR-421. A tumour growth curve is shown for 28 days. The data represent the mean ± SD (n = 5). k Quantification of the body weights of mice from each group. The data are presented as the mean ± SD; n = 5 per group