title: Effect of CpG island methylation on microRNA expression in the k-562 cell line.
abstract: To test the hypothesis that methylation of a CpG island is associated with regulation of microRNA expression, we investigated CpG islands in the upstream sequences of microRNA precursors (pre-miRNAs) through bioinformatic analysis and determined whether the CpG islands were methylated by methylation-specific PCR in the k-562 cell line. We used 5-azacytidine for DNA demethylation, and changes in microRNA expression were detected by microarray assay, RT-PCR, and real-time PCR after 5-azacytidine induction. We showed that the CpG islands in the upstream regions of 18 pre-miRNAs were methylated, including miR-663, miR-369, miR-615, and miR-410, and promoter activity was detected in the upstream region of pre-miR-663. We found that a decrease in methylation of a CpG island could up-regulate the expression of miR-663, suggesting that miR-663 could be regulated by DNA methylation. Expression levels of miR-369, miR-615, and miR-410 were not regulated by DNA methylation in this cell line.
authors.affiliation: Department of Hematology and BMT Center, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Li
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Gao
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Yu
mesh_terms: D001374:Azacitidine / Q000494:pharmacology; D018899:CpG Islands; D019175:DNA Methylation / Q000187:drug effects; D005786:Gene Expression Regulation; D006801:Humans; D020014:K562 Cells; D035683:MicroRNAs / Q000235:genetics*; D009363:Neoplasm Proteins; D011401:Promoter Regions, Genetic; D012322:RNA Precursors; D060888:Real-Time Polymerase Chain Reaction
chemical_list: C560308:MIRN369 microRNA, human; C568527:MIRN410 microRNA, human; C534344:MIRN615 microRNA, human; C552243:MIRN663 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D012322:RNA Precursors; C470990:URGCP protein, human; D001374:Azacitidine