Frequent promoter hypermethylation and transcriptional downregulation of the NDRG2 gene at 14q11.2 in primary glioblastoma

Martin Tepel, Peter Roerig, Marietta Wolter, David H. Gutmann, Arie Perry, Guido Reifenberger, Markus J. Riemenschneider

Research output: Contribution to journalArticle

67 Scopus citations

Abstract

The N-myc downstream-regulated gene 2 (NDRG2) at 14q11.2 has been reported to be downregulated in glioblastoma, and NDRG2 overexpression represses glioblastoma cell proliferation in vitro (Deng et al., Int J Cancer 2003;106;342-7). To further address the role of NDRG2 as a candidate tumor suppressor in human gliomas, we analyzed 67 astrocytic tumors (10 diffuse astrocytomas, 11 anaplastic astrocytomas, 34 primary glioblastomas and 12 secondary glioblastomas) for NDRG2 gene mutation, promoter methylation and expression at the mRNA and protein levels. Using real-time reverse transcription PCR analysis, we found decreased NDRG2 mRNA levels in primary glioblastomas as compared to diffuse and anaplastic astrocytomas. Similarly, immunohistochemistry revealed low or absent NDRG2 protein expression in primary glioblastomas. Mutational analysis of the entire NDRG2 coding sequence did not reveal any tumor-associated DNA sequence alterations. However, sequencing of sodium bisulfite-modified DNA identified hypermethylation of the NDRG2 promoter region in 21 of 34 primary glioblastomas (62%). Moreover, NDRG2 promoter hypermethylation was associated with decreased NDRG2 mRNA expression. In contrast to primary glioblastomas, NDRG2 promoter hypermethylation was detected in only 1 of 11 anaplastic astrocytomas (9%) and was absent in 10 diffuse astrocytomas and 12 secondary glioblastomas. Taken together, our data support NDRG2 as a candidate tumor suppressor gene that is epigenetically silenced in the majority of primary glioblastomas, but not in lower grade astrocytomas and secondary glioblastomas.

Original languageEnglish
Pages (from-to)2080-2086
Number of pages7
JournalInternational Journal of Cancer
Volume123
Issue number9
DOIs
StatePublished - Nov 1 2008

Keywords

  • Astrocytoma
  • Brain tumor
  • Epigenetic
  • Glioma
  • Tumor suppressor

Fingerprint Dive into the research topics of 'Frequent promoter hypermethylation and transcriptional downregulation of the NDRG2 gene at 14q11.2 in primary glioblastoma'. Together they form a unique fingerprint.

  • Cite this