Genome-wide analysis of DNA methylation and expression of microRNAs in breast cancer cells

Sumiyo Morita, Ryou u. Takahashi, Riu Yamashita, Atsushi Toyoda, Takuro Horii, Mika Kimura, Asao Fujiyama, Kenta Nakai, Shoji Tajima, Ryo Matoba, Takahiro Ochiya, Izuho Hatada

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


DNA methylation of promoters is linked to transcriptional silencing of protein-coding genes, and its alteration plays important roles in cancer formation. For example, hypermethylation of tumor suppressor genes has been seen in some cancers. Alteration of methylation in the promoters of microRNAs (miRNAs) has also been linked to transcriptional changes in cancers; however, no systematic studies of methylation and transcription of miRNAs have been reported. In the present study, to clarify the relation between DNA methylation and transcription of miRNAs, next-generation sequencing and microarrays were used to analyze the methylation and expression of miRNAs, protein-coding genes, other non-coding RNAs (ncRNAs), and pseudogenes in the human breast cancer cell lines MCF7 and the adriamycin (ADR) resistant cell line MCF7/ADR. DNA methylation in the proximal promoter of miRNAs is tightly linked to transcriptional silencing, as it is with protein-coding genes. In protein-coding genes, highly expressed genes have CpG-rich proximal promoters whereas weakly expressed genes do not. This is only rarely observed in other gene categories, including miRNAs. The present study highlights the epigenetic similarities and differences between miRNA and protein-coding genes.

Original languageEnglish
Pages (from-to)8259-8272
Number of pages14
JournalInternational journal of molecular sciences
Issue number7
Publication statusPublished - 2012 Jul


  • Cancer
  • DNA methylation
  • MicroRNA

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry


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