Roles of microRNAs and other non-coding RNAs in breast cancer metastasis.

Despite the fact that metastases are responsible for the overwhelming majority of human cancer deaths, our comprehension of the molecular events that drive metastatic progression remains woefully incomplete. Excitingly, the recent appreciation that various species of non-coding RNAs—including microRNAs—play pivotal roles in dictating the malignant behaviors of breast carcinoma cells promises to afford new insights into the molecular circuitry that determines metastatic propensity. Here, I summarize our current knowledge regarding these still-emerging functions for non-coding RNAs in the pathogenesis of breast cancer metastasis, with an emphasis placed upon the roles played by microRNAs in these processes. Additionally, I discuss the potential translational opportunities afforded by these research findings for the diagnosis and treatment of human breast tumors. When assessed collectively, it is apparent that although this field of research is still in its infancy, comprehension of the biological actions of microRNAs and other non-coding RNAs will hold important consequences for our understanding of the etiology of metastatic disease, as well as its clinical management and treatment.