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57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN)

German Society for Neuropathology and Neuroanatomy

12. - 15.09.2012, Erlangen

57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN)

Molecular analysis of MTSS1 in gliomas

Meeting Abstract

  • presenting/speaker Daniel Luxen - University of Bonn, Neuropathology, Bonn, Germany
  • Marco Gessi - University of Bonn, Neuropathology, Bonn, Germany
  • Lukas Jan Isselstein - University of Bonn, Neuropathology, Bonn, Germany
  • Tim Müller - University of Bonn, Neuropathology, Bonn, Germany
  • Dorothee Freihoff - University of Bonn, Neuropathology, Bonn, Germany
  • Johannes Freihoff - University of Bonn, Neuropathology, Bonn, Germany
  • Matthias Simon - University of Bonn, Neurosurgery, Bonn, Germany
  • Torsten Pietsch - University of Bonn, Neuropathology, Bonn, Germany
  • Anke Waha - University of Bonn, Neuropathology, Bonn, Germany
  • Andreas Waha - University of Bonn, Neuropathology, Bonn, Germany

Deutsche Gesellschaft für Neuropathologie und Neuroanatomie. 57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN). Erlangen, 12.-15.09.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. Doc12dgnnPP3.20

DOI: 10.3205/12dgnn064, URN: urn:nbn:de:0183-12dgnn0645

Published: September 11, 2012

© 2012 Luxen et al.
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Outline

Text

In a genome-wide methylation analysis, the metastasis suppressor-1 (MTSS1) gene was identified as a novel gene hypermethylated in gliomas. MTSS1 has been associated with cross linking and membrane attachment of actin filaments. In addition, MTSS1 acts as sonic hedgehog induced transcriptional regulator enhancing transcription of Gli target genes. Here we investigate MTSS1 methylation, allelic loss and expression in 63 gliomas and 6 glioma cell lines by pyrosequencing, realtime RT-PCR and IHC. In addition we transfected glioma cells with MTSS1-EGFP to study the localization as well as the functional impact of MTSS1 proteinin vitro.

MTSS1 hypermethylation was frequently found in anaplastic astrocytomas (AAIII) and secondary glioblastomas (sGBM-IV) where it correlated with IDH1 mutational status (P=0.0001). Epigenetic silencing of MTSS1 by DNA methylation was confirmed by treatment of glioma cell lines with the demethylating agent 5-aza 2' deoxycytidine. Although 30% of investigated glioblastoma tissues showed reduced MTSS1 mRNA, no significant correlation between MTSS1 methylation and transcript levels was found. Allelic loss was identified in 2/9 and 2/6 of informative AAIII and sGBM-IV respectively, whereas only 2/22 investigated primary glioblastomas showed loss of MTSS1alleles.

MTSS1-EGFP transfected glioma cells LN229 and U87MG showed staining of focal contact structures suggesting a role of MTSS1 in cellular adhesion. In line with this assumption, a significant negative impact of MTSS1 protein expression on the migration and invasion of glioma cells was confirmed in scratch assays and trans-well chamber analyses. Flow cytometric studies of MTSS1 transfected glioma cells showed a significant increase of apoptosis, whereas no alteration of cellular proliferation was observed. We conclude that inactivation of MTSS1 contributes to the molecular pathology of gliomas by reducing attachment and apoptosis and enhancing migration/invasion and survival of glioma cells.