MicroRNAs dysregulated in breast cancer preferentially target key oncogenic pathways.

MicroRNA (miRNA) dysregulation has been associated with numerous cancers including breast cancer. The dysregulation of miRNAs in cancer has been shown to perturb various pathways, with oncogenic effects. Here we investigate the relationship between dysregulated miRNAs and pathways involved in breast cancer by integrating miRNA and mRNA expression data. From a list of dysregulated miRNAs, we started by selecting the subset that appear to be regulating genes differentially expressed in breast cancer vs. normal tissue. Individually and as a group, this subset was found to target several canonical oncogenic pathways including the p53 signalling pathway, MAPK signalling pathway, TGFβ signalling pathway, focal adhesion and cell cycle progression. These results suggest that the dysregulation of miRNAs in breast cancer not only results in widespread changes to gene expression, but also the dysregulation of key oncogenic pathways.