Changes in the <i>MIR-143</i. gene methylation pattern in the tumor tissue of the diffuse large B-cell lymphoma

The study of DNA methylation status in malignant lymphomas is a new field of research in oncohematology. The aim of this study was to quantify the level of methylation of the MIR-143 gene in the tumor tissue of patients with diffuse large B-cell lymphoma (DLBCL). Material and methods. The study included 81 tumor samples of DLBCL (26 of germinal and 55 of non-germinal origin) and 11 biopsies of reactive lymph nodes. To quantify the methylation of the MIR-143 gene, the method of direct bisulfite sequencing by Sanger was used with the calculation of the average level of methylation of the analyzed CpG-sites. Results. The average level of MIR-143 methylation in tumor samples was significantly lower than the values in reactive lymph nodes (64.43 ± 19.92 и 76.27 ± 4.92 %, respectively, p = 0.049), did not depend on the immunohistochemical subtype of the tumor and showed a greater spread of values. In the lymphoma samples, there was predominant hypomethylation of one of the four analyzed CpG-dinucleotides within the boundaries of the analyzed fragment. Conclusion. The data on a change in the pattern of the MIR-143 gene methylation in the tumor tissue of DLBCL were obtained. To establish the role of microRNA in the pathogenesis of DLBCL further studies aimed at clarifying the mechanisms of epigenetic regulation of MIR-143 expression in lymphoma cells and identification of this microRNA targets are required.