Figure 2.

MiR-20a/b inhibits the proliferation and chemoresistance of breast cancer cells in vitro. (a) Overexpression of miR-20a/b inhibits cell proliferation and chemoresistance. Cell proliferation was detected by MTT assay. (b) Overexpression of miR-20a/b increased the sensitivity of BCap37 and Bads-200 cell lines to PTX (up), and inhibition of miR-20a/b enhanced the resistance of BCap37 and Bads-200 cells to PTX (down). Cell growth rate was evaluated using MTT assay. (c) The apoptotic rate of the indicated cells transfected with miR-20a, or negative controls or together with PTX treatment. (d and e) MiR-20a inhibits cell colony formation. Colony formation (d) and soft agar (e) assays were performed in BCap37 cells (left) and Bads-200 cells (right) transfected with miR-20a or their negative controls or together with PTX treatment. Results from a representative experiment performed in triplicate. Bar, 500 μm. (f) Enhanced response to PTX by miR-20a overexpression is shown in multiple breast cancer cell lines, including HS-578bst, MCF-7, MDA-MB-231 and BT-474. (g) MiR-20a enhances the sensitivity of breast cancer cell lines Bcap37 (left) and Bads-200 (right) to multiple anticancer drugs. VNB, Vinorelbine; DOX, Doxorubicin; GEM, Gemcitabine; 5-FU, 5- Fluorouracil; CPT, Cisplatin. *P<0.05, **P<0.01, ***P<0.001