MicroRNAs in development and progression of breast cancer

Abstract

Over the past several years, it has become clear that alterations in the expression of microRNA (miRNA) genes contribute to the pathogenesis of most human malignancies. These alterations can be caused by various mechanisms, including deletions, amplifications, or mutations involving miRNA loci, epigenetic silencing, or the dysregulation of transcription factors that target specific miRNAs. Further, every cellular process is likely to be regulated by miRNAs and an aberrant miRNA expression signature is a hallmark of several diseases, including breast cancer. miRNA expression profiling has provided evidence of the association of these molecules with tumor development and progression. An increasing number of evidences have demonstrated that miRNAs can function as either potential oncogenes or tumor suppressor genes, depending on the cellular context and on the target genes they regulate. Here, we review our current knowledge about the involvement of miRNAs in breast cancer and their potential as diagnostic, prognostic, and therapeutic tools.