Elena Pudova11EIMB RAS, pudova_elena@inbox.ru Metastatic castration-resistant prostate cancer (mCRPC) is characterized by a high mortality rate due to its aggressiveness. In the field of modern oncourology, monitoring the activity of a disease for patients of this category during therapy is an important clinical problem, for the solution of which informative markers are needed. Circulating microRNAs can serve as such markers, which demonstrate diagnostic and prognostic potential in various types of cancer, including prostate cancer. The aim of this study is to search for circulating miRNAs of mCRPC patients plasma during therapy that are potentially associated with the progression of the disease, as well as to study the contribution of these miRNAs to the general progression mechanism. Based on high-throughput sequencing, a bioinformatic analysis was carried out with identification of the microRNA profile potentially associated with the progression of the disease (p-value <0.05): miR-221-3p, miR-99b-3p, miR-145-5p, miR-375-3p, miR-20a-5p, miR-21-5p, miR-451a, miR-199a-5p, miR-183-5p, miR-let-7i-5p and miR-let-7f-5p.