RESUMO
MicroRNAs (miRNAs) are short non-coding RNAs (18-25 nucleotides in length) that are important participants in the regulation of gene expression. In 2003, their active role in oncogenesis was demonstrated. In 2008, the first report on the isolation of miRNAs from uveal melanoma (UM) tissue was published. Four years later (2012), the presence of miRNAs in the plasma of patients with this category was shown. To date, changes in the expression level of 100 miRNAs in the plasma of cancer patients (with cancer of various localizations) out of the 2654 miRNAs described in mirbase.org have been proven. In the plasma of patients with UM, changes in the expression of only 13 miRNAs have been confirmed. As a rule, studies were conducted in patients at the stage of hematogenous metastasis of UM. PURPOSE: This study analyzed the expression pattern of miRNA-223 and miRNA-126 in patients with localized choroidal melanoma (CM) taking into account biometric parameters in the absence of metastases. MATERIAL AND METHODS: Blood plasma of 84 patients with M0N0 CM aged 35-86 years (mean age 63.4±1.2 years) was investigated. The basis for the diagnosis of CM was the results of ophthalmological examination, optical coherence tomography, and ultrasound scanning. In all cases, the absence of metastases was proven (using computed tomography or magnetic resonance imaging). Control - plasma of 28 volunteers (mean age 62.9±1.42 years, age range 45-78 years), who did not have tumoral, autoimmune, or chronic inflammatory processes. The expression levels of miRNAs circulating in blood plasma were determined by real-time polymerase chain reaction. RESULTS: An increase in the expression levels of miRNA-223 and miRNA-126 in the plasma of all 84 patients with CM was confirmed compared to the control group. Features of the miRNA expression pattern that emerged with changes in the tumor's quantitative parameters were identified. CONCLUSION: Evaluation of the levels of miRNA-223 and miRNA-126 in the blood plasma of patients with CM can be used in clinical practice to clarify the diagnosis of CM, as well as to predict the development of hematogenous metastases.
