The role of miRNAs in the pathogenesis, diagnosis, and treatment of colorectal cancer and colitis-associated cancer.

MicroRNAs (miRNAs) are a group of noncoding single-stranded RNA biomolecules that act in posttranscriptional regulation of gene expression. Their role in the development of inflammatory bowel disease (IBD), colitis-associated cancer (CAC), and colorectal cancer (CRC) is currently under investigation. A few miRNAs present promising results in terms of diagnostic or therapeutic use, for example, miR-21 increases in CRC and inflammation, while also being a possible target for cancer therapy; miR-301a increases in inflammation but only in patients with IBD; miR-31 increases in CRC, especially in advanced stages, namely III-IV in TNM scale; miR-200 family plays a role in carcinogenesis of CRC and other tumors; examined as a group, miR-31-5p, miR-223-3p, and let-7f-5p trigger and exacerbate CAC; miR-19a could potentially be used in therapy and prevention of both CRC and CAC. Here, we discuss available studies and outline future directions concerning the validity of using miRNAs in the diagnosis and/or therapy of IBD, CAC, and CRC. Extensive research confirms that miRNAs play an important role in the pathogenesis of CAC and CRC. Since the significantly altered expression of certain miRNAs is an early prognostic marker for the development of these diseases, miRNAs have the potential to serve as diagnostic tools, enabling quick and straightforward disease detection.