Aberrant microRNA expression in the development of breast carcinoma

microRNAs, a class of small non-coding regulatory RNAs, are involved in oncogenesis and cancer development. Studies have shown that aberrant miRNA expression occurs in breast cancer and is associated with specific clinicopathological features. Some miRNAs might act as suppressor genes or oncogenes, which can be considered as novel markers for breast cancer diagnosis and as prognostic factors. Here we present a review of recent discoveries on miRNAs involved in breast cancer tumorigenesis, invasion, and metastasis.