Figure 6

Knockdown of miR-33b promotes the migration and invasion capabilities of MCF-10A cells and re-expression of HMGA2 and Twist1 reverses miR-33b-dependent self-renewal and invasion-relevant phenotypes of MDA-MB-231 cells.

(A,B) Transwell migration (A) and Matrigel-coated Transwell invasion (B) analyses revealed that knockdown of miR-33b promoted the migration and invasion of MCF-10A cells in vitro. (C) qRT-PCR analysis revealed that the knockdown of miR-33b upregulated the mRNA expression of the metastasis-related genes LOX, MMP-2, MMP-9 and CXCR4 in MCF-10A cells. (D) Western blot analysis of metastasis-related proteins LOX, FN and p-FAK. These proteins were upregulated after miR-33b knockdown in MCF-10A cells. (E, F) Western blot analysis of the re-expression of HMGA2 and Twist1 in MDA-MB-231/miR-33b cells. The full-length blots were presented in the Supplementary Figure 11. (G) Migration assays with the indicated MDA-MB-231 cells transfected with miRNA-resistant expression constructs. Control represents the scrambled miRNA used for miR-33b overexpression and vector represents the empty vector used for HMGA2 and Twist1 re-expression. (H) Quantification of migration assays with the indicated MDA-MB-231 cells transfected with miRNA-resistant expression constructs in (G). (I) Quantification of mammosphere formation assays with the indicated MDA-MB-231 cells transfected with miRNA-resistant expression constructs. Scale bars, 100 μm. Data represent mean ± s.d. **: P <0.01, ***: P <0.001.