Fig. 3

Overexpression of miR-21 and WIP1 promotes oncogenic transformation of HER2+ breast cancer cells. a The differential expression heat map of miR-21 target genes in the mammary epithelial cells (MMECs) derived from MIR21−/−;MMTV-ErbB2 mice (8 weeks old). b Relative expression levels of the predicted miR-21 targets in primary MMECs isolated from wild-type or MIR21-/- virgin females at the age of 8 weeks. Data represents the mean expression levels normalized to the endogenous snoRNA55 control from three independent experiments. c MMECs derived from MMTV-ErbB2 mice were transduced with lentivirus expressing miR-21 and/or WIP1. Top panel: representative photomicrographs of SA-β-galactosidase (SA-β-Gal) staining observed in bright field. Bottom panel: miR-21 and WIP1 expression levels as determined by q-PCR, and percentages of SA-β-Gal-positive cells were calculated. Scale bar, 10 µm. *p < 0.05; **p < 0.01; unpaired 2-tailed t-test was used (b, c). Data are presented as mean ± SD and are representative of 3 independent experiments