MicroRNAs in colorectal neoplasia: from pathobiology to clinical applications.

MicroRNAs (miRNAs) are small, non-coding RNAs that can post-transcriptionally regulate gene expression via messenger RNA (mRNA) targeting. During the past few years several miRNA groups emerged as critical components of developmental and pathological processes, among them being cancer. In colorectal cancer (CRC) specifically, numerous miRNA molecules have been identified up- or downregulated functioning as tumor-specific markers with oncogenic and tumor-suppressive properties. Their dysregulation impacts impaired cellular processes such as cell proliferation, apoptosis, angiogenesis, invasion and metastasis. The detection of extracellular miRNAs in plasma and fecal samples of CRC patients tends to provide novel, non-invasive biomarkers in favor of CRC diagnosis and, at the same time, data from in vivo and in vitro CRC models reveal promising therapeutic applications through miRNA inhibition and miRNA delivery.