Results of MTT assay showing the effect of miR-200a, miR-200b, miR-15a, miR-429, miR-203 in MDAMB-231 cells. Scramble miRNA vector was used as a control. Error bars indicate ±S.E of n = 3 (A). Results of BrdU assay showing the effect of miR-200a, miR-200b, miR-15a, miR-429, miR-203 in MDAMB-231 cells. Scramble miRNA vector was used as control. Error bars indicate ±S.E of n = 3 (B). Western blot analysis showing expression of BMI1, Ub-H2A, ABCG2, MDM2, pro-apoptotic and anti-apoptotic proteins like BAX, BID, BCL2, Caspase-3 in miR-15a overexpressed cells with cisplatin treatment. Scramble miRNA transfected cells served as control. β-Actin was used as gel loading control (C). Caspase-3 assay and Tunel assay were performed in MDAMB-231 containing ectopically expressed miR-15a with cisplatin treatment. Scramble miRNA transfected cells served as control. Cells with only cisplatin treatment served as positive control (D, E). Immunocytochemistry studies of above group of cells showing expression of ABCG2 (F).