The impact of microRNAs on colorectal cancer.

MicroRNAs are small RNAs that regulate gene expression at the post-transcriptional level. After their discovery 15 years ago, a new layer of gene regulation was introduced into every field of human biology and medicine. Considering the strong association between genetic alterations and neoplastic diseases, it is not surprising that there is a special focus on miRNAs and cancer. A multitude of experimental studies on colorectal cancer, the most common cancer site and furthermore the second most common cause of death due to cancer, deliver insight into miRNA-mediated, regulatory links to well-known oncogenic and tumour suppressor signalling pathways. Furthermore, several investigations have described the ability of microRNA expression patterns to predict prognosis in colon cancer and support diagnosis of poorly differentiated tumours. In this short review, we give a comprehensive overview focussed on miRNAs in colorectal cancer research.