miRNAs can both promote and repress tumorigenesis, and directly control epithelial–mesenchymal transition (EMT). miR-9 (which is upregulated in breast cancer cells) is activated by MYC and MYCN, and regulates EMT and metastasis through direct control of E-cadherin. In contrast, tumour angiogenesis is controlled indirectly through effects on vascular endothelial growth factor (VEGF) expression.
- Li Ma
- Jennifer Young
- Robert A. Weinberg
