The role of microRNAs in cancer: diagnostic and prognostic biomarkers and targets of therapies

Introduction: miRNAs are noncoding RNAs that target specific mRNA with subsequent regulation of particular genes, implicated in various biological processes. In cancer, miRNAs could show a different expression from normal tissues. miRNAs have a role as oncogenes when they target tumor suppressor genes and similarly they are tumor suppressors when they target oncogenes. Areas covered: In this review, areas covered include the role of miRNAs in cancer diagnosis, prognosis and research for achievement of therapeutic strategies implicating miRNAs in oncology. As biogenesis of miRNAs is fundamental to understand their usefulness, this has also been discussed. Both miRNA expression profiles in cancer tissues and miRNA levels in peripheral blood were studied for improvement in the management of cancer patients. Expert opinion: miRNAs have the potential for better understanding of tumor biology, but could also provide clinical advancement in management and therapy of various malignancies. The possibility of miRNA detection in peripheralblood would allow an eager expansion of their application in variousclinical settings for cancer. The applicability of miRNA expression profiles still needs to be defined