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Vol 51(2017) N 1 p. 61-71; DOI 10.1134/S0026893316060169  I.V. Pronina1,2*, E.A. Klimov3, A.M. Burdennyy2,4, E.V. Beresneva5, M.V. Fridman6, V.D. Ermilova7, T.P. Kazubskaya7, A.V. Karpukhin1, E.A. Braga1,2, V.I. Loginov1,2** Methylation of the genes for the microRNAs miR-129-2 and miR-9-1, changes in their expression, and activation of their potential target genes in clear cell renal cell carcinoma 1Research Centre of Medical Genetics, Moscow, 115478 Russia2Institute of General Pathology and Pathophysiology, Moscow, 125315 Russia 3Biological Faculty, Moscow State University, Moscow, 119234 Russia 4Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334 Russia 5State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, 117545 Russia 6Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 117971 Russia 7Blokhin Cancer Research Center, Moscow, 115478 Russia *zolly_sten@mail.ru **loginov7w@gmail.com Received - 2015-09-21; Accepted - 2015-11-23 Methylation of promoter CpG islands and microRNA (miRNA) interactions with mRNAs of target genes are epigenetic mechanisms that play a crucial role in deregulation of gene expression and signaling pathways in tumors. Altered expression of six chromosome 3p genes (RARB(2), SEMA3B, RHOA, GPX1, NKIRAS1, and CHL1) and two miRNA genes (MIR-129-2 and MIR-9-1) was observed in primary clear cell renal cell carcinomas (ccRCCs, 31-48 samples) by RT-PCR and qPCR. Significant downregulation (p < 0.05, Fisher's exact test) was observed for SEMA3B, NKIRAS1, and CHL1; and differential expression, for the other chromosome 3p and miRNA genes. Methylation-specific PCR with primers to RARB(2), SEMA3B, MIR-129-2, and MIR-9-1 showed that their methylation frequency was significantly (p < 0.05, Fisher's exact test) elevated in the ccRCC samples. Significant correlations between promoter methylation and expression were confirmed for SEMA3B and observed for the first time for RARB(2), GPX1, and MIR-129-2 in ccRCC (Spearman's correlation coefficient rs ranging 0.31-0.60, p < 0.05). The MIR-129-2 and RARB(2) methylation frequencies significantly correlated with ccRCC progression. MIR-129-2 methylation correlated with upregulation of RARB(2), RHOA, NKIRAS1, and CHL1 (rs ranging 0.35-0.53, p < 0.05). The findings implicate methylation in regulating RARB(2), SEMA3B, GPX1, and MIR-129-2 and indicate that miR-129-2 and methylation of its gene affect RARB(2), RHOA, NKIRAS1, and CHL1 expression. epigenetic mechanisms, expression regulation, methylation, renal cell carcinoma, chromosome 3 genes, microRNA, miR-129-2 |
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