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So AY, Jung JW, Lee S, Kim HS, Kang KS. DNA methyltransferase controls stem cell aging by regulating BMI1 and EZH2 through microRNAs. PLoS One 2011; 6:e19503. [PMID: 21572997 PMCID: PMC3091856 DOI: 10.1371/journal.pone.0019503] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/30/2011] [Indexed: 12/30/2022] Open
Abstract
Epigenetic regulation of gene expression is well known mechanism that regulates cellular senescence of cancer cells. Here we show that inhibition of DNA methyltransferases (DNMTs) with 5-azacytidine (5-AzaC) or with specific small interfering RNA (siRNA) against DNMT1 and 3b induced the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) and increased p16(INK4A) and p21(CIP1/WAF1) expression. DNMT inhibition changed histone marks into the active forms and decreased the methylation of CpG islands in the p16(INK4A) and p21(CIP1/WAF1) promoter regions. Enrichment of EZH2, the key factor that methylates histone H3 lysine 9 and 27 residues, was decreased on the p16(INK4A) and p21(CIP1/WAF1) promoter regions. We found that DNMT inhibition decreased expression levels of Polycomb-group (PcG) proteins and increased expression of microRNAs (miRNAs), which target PcG proteins. Decreased CpG island methylation and increased levels of active histone marks at genomic regions encoding miRNAs were observed after 5-AzaC treatment. Taken together, DNMTs have a critical role in regulating the cellular senescence of hUCB-MSCs through controlling not only the DNA methylation status but also active/inactive histone marks at genomic regions of PcG-targeting miRNAs and p16(INK4A) and p21(CIP1/WAF1) promoter regions.
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Affiliation(s)
- Ah-Young So
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Ji-Won Jung
- Division of Intractable Diseases, Center for Biomedical Sciences, Korea National Institute of Health, Chungbuk, Republic of Korea
| | - Seunghee Lee
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Hyung-Sik Kim
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Kyung-Sun Kang
- Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
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