Schmidt, Natalie and Windmann, Sonja and Reifenberger, Guido and Riemenschneider, Markus J. (2012) DNA Hypermethylation and Histone Modifications Downregulate the Candidate Tumor Suppressor Gene RRP22 on 22q12 in Human Gliomas. BRAIN PATHOLOGY, 22 (1). pp. 17-25. ISSN 1015-6305,
Full text not available from this repository. (Request a copy)Abstract
RRP22 (Ras-related protein on chromosome 22) has been suggested as a candidate tumor suppressor in human cancers. Investigating a panel of 70 human gliomas, we found a frequent decrease in the RRP22 mRNA expression levels (67%), preferentially in high-grade gliomas [World Health Organization (WHO) grades III and IV] as compared with low-grade gliomas (WHO grade II). Moreover, reduced RRP22 mRNA expression was associated with shorter overall survival in 180 glioblastoma patients included in the National Institutes of Health Repository for Molecular Brain Neoplasia Data (NIH REMBRANDT) database. Decreased RRP22 expression levels were in part explained by 5'-CpG island hypermethylation and increased by the treatment with the demethylating agent 5-aza-2'-deoxycytidine in glioblastoma cell lines. In addition, the in vitro treatment with the histone deacetylase inhibitor trichostatin A alone resulted in RRP22 reexpression as well as a significant increase in the levels of RRP22 promoter DNA bound to pan-acetylated histone H3 and H4. Moreover, in primary human glioblastomas, we observed an increase of H3K9me3-bound and a decrease of pan-Ac-H3-bound RRP22 in comparison with non-neoplastic brain tissue, consistent with a heterochromatinization of the RRP22 promoter. Taken together, our findings demonstrate that both 5'-CpG island hypermethylation and histone modifications contribute to the frequent and prognostically unfavorable transcriptional downregulation of RRP22 in malignant gliomas.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | OLIGODENDROGLIAL TUMORS; CHROMATIN MODIFICATIONS; PRIMARY GLIOBLASTOMA; MALIGNANCY; EXPRESSION; REGIONS; 1P; astrocytoma; brain tumor; chromatin immunoprecipitation; glioblastoma; methylation; RASL10A |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Abteilung für Neuropathologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 26 May 2020 05:00 |
| Last Modified: | 26 May 2020 05:00 |
| URI: | https://pred.uni-regensburg.de/id/eprint/19601 |
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