Synergism between DNA methylation and macroH2A1 occupancy in epigenetic silencing of the tumor suppressor gene p16(CDKN2A)
| Autor: | Sara Isaac, Amir Eden, Nathalie Friedman, Michal Barzily-Rokni, Dan Michlin, Shulamit Ron-Bigger |
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| Rok vydání: | 2010 |
| Předmět: |
Tumor suppressor gene
Heterochromatin Gene Regulation Chromatin and Epigenetics medicine.disease_cause Cell Line Histones Cell Line Tumor Histone methylation Genetics medicine Humans Genes Tumor Suppressor Gene Silencing Cancer epigenetics Promoter Regions Genetic Alleles biology Genes p16 DNA Methylation Histone DNA demethylation Gene Knockdown Techniques Colonic Neoplasms DNA methylation biology.protein Cancer research Carcinogenesis |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/gkq994 |
| Popis: | Promoter hypermethylation and heterochromatinization is a frequent event leading to gene inactivation and tumorigenesis. At the molecular level, inactivation of tumor suppressor genes in cancer has many similarities to the inactive X chromosome in female cells and is defined and maintained by DNA methylation and characteristic histone modifications. In addition, the inactive-X is marked by the histone macroH2A, a variant of H2A with a large non-histone region of unknown function. Studying tumor suppressor genes (TSGs) silenced in cancer cell lines, we find that when active, these promoters are associated with H2A.Z but become enriched for macroH2A1 once silenced. Knockdown of macroH2A1 was not sufficient for reactivation of silenced genes. However, when combined with DNA demethylation, macroH2A1 deficiency significantly enhanced reactivation of the tumor suppressor genes p16, MLH1 and Timp3 and inhibited cell proliferation. Our findings link macroH2A1 to heterochromatin of epigenetically silenced cancer genes and indicate synergism between macroH2A1 and DNA methylation in maintenance of the silenced state. |
| Databáze: | OpenAIRE |
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