RESUMEN
Breast cancer is the most common form of cancer in women. Despite extensive study, the etiology of breast cancer remains ambiguous. A group of genetic modifiers known as microRNAs (miRNAs) are emerging onto the scene of breast cancer research. MicroRNAs are small, non-coding RNAs that are involved in the regulation of key cellular processes such as proliferation, differentiation, and apoptosis. They can interfere directly with the translation and stability of a targeted gene transcript and cause a disturbance in the cell physiology. The dysregulation of both oncogenes and tumor suppressor genes by aberrant miRNA production can result in the progression to breast cancer. This review provides a discussion of the nature of miRNAs, explains the role of miRNAs in the etiology and progression of breast cancer, and discusses their potentials as therapeutic molecules and diagnostic markers.