[Circulating microRNAs in the diagnostics of endocrine neoplasms]

MicroRNAs (miRNA, miR) are short - 19-25 nucleotide long - single stranded (in their mature form), non-coding RNA molecules that regulate gene expression mostly at the posttranscriptional level. microRNAs are involved in the regulation of various physiological processes such as cell differentiation and proliferation, development, haematopoesis, cell death, while their aberrant expression is observed in numerous diseases, like autoimmune disorders, inflammations, vascular diseases or tumorigenesis. microRNAs are expressed in a tissue specific fashion. Beyond their appearance in tissues, they can be found in body fluids as well. microRNAs are present in blood, mother milk, semen, saliva, urine, etc. MicroRNAs in body fluids, especially the blood-borne circulating microRNAs can be exploited as minimally invasive biomarkers of tumor diagnosis. The number of endocrine tumor-associated circulating microRNA alterations is relatively low, mostly described for papillary thyroid cancer, adrenocortical cancer, ovarian and neuroendocrine tumors. As the histological diagnosis including the establishment of malignancy of some of these neoplasms is difficult, studies on circulating microRNAs might have great perspectives. Orv. Hetil., 2017, 158(13), 483-490.