Fig. 2

Suppression of miR-21 and WIP1 inhibits proliferation and tumorigenic potential of HER2+ breast cancer cells. a Kaplan–Meier analysis of tumor-free survival in female MMTV-ErbB2 wild type (n = 12), MMTV-ErbB2; WIP1^−/− (n = 12) and MMTV-ErbB2; MIR21^−/− (n = 13) mice. b Amplification of MIR21 and WIP1 is associated with poor overall survival in patients with HER2+ breast cancer, but not with patients with luminal A, luminal B or basal-like breast cancer. c Cell growth curve of H605 cells (MMTV-ErbB2 tumor cells) expressing doxycline (Dox)-inducible control shRNA or specific shRNA targeting WIP1 or mature miR-21. d Mammosphere formation assay in H605 cells expressing Dox-inducible control shRNA, specific shRNA targeting WIP1 or mature miR-21. Right panel demonstrates the quantitative data using Image J software. Scale bar, 500 µm. *p < 0.05; ***p < 0.001**; ***p < 0.001; Log-rank Mantel–Cox test (a, b) and one-way ANOVA followed by Tukey’s t test (c, d) were used. Data are presented as mean ± SD and are representative of 3 independent experiments