Oncogenic microRNAs (OncomiRs) as a new class of cancer biomarkers.

Small non-coding RNAs (microRNAs or miRs) represent one of the most fertile areas of cancer research and recent advances in the field have prompted us to reconsider the traditional concept of cancer. Some miRs exert negative control over the expression of numerous oncoproteins in normal cells and consequently their deregulation is believed to be an important mechanism underlying cancer development and progression. Owing to their distinct patterns of expression associated with cancer type, remarkable stability and presence in blood and other body fluids, miRs are considered to be highly promising cancer biomarkers. The identification of "miR signatures" associating cancer cell phenotypes with disease outcome and specific risk factor exposures will undoubtedly open new avenues for early diagnosis and therapy of cancer, as well as for the development of novel strategies for cancer prevention.