gms | German Medical Science

62nd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Polish Society of Neurosurgeons (PNCH)

German Society of Neurosurgery (DGNC)

7 - 11 May 2011, Hamburg

Epigenetic DNA methylation analysis as a diagnostic tool for brain tumors

Meeting Abstract

  • A.M. Barciszewska - Klinikum für Neurochirurgie und Neurotraumatologie, Karol Marcinkowski Universität für Medizinische Wissenschaften, Poznan, Polen
  • S. Nowak - Klinikum für Neurochirurgie und Neurotraumatologie, Karol Marcinkowski Universität für Medizinische Wissenschaften, Poznan, Polen
  • I. Gawronska - Institut für Bioorganische Chemie, Polnische Akademie den Wissenschaften, Poznan, Polen
  • M.Z. Barciszewska - Institut für Bioorganische Chemie, Polnische Akademie den Wissenschaften, Poznan, Polen

Deutsche Gesellschaft für Neurochirurgie. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocMI.05.07

doi: 10.3205/11dgnc216, urn:nbn:de:0183-11dgnc2166

Published: April 28, 2011

© 2011 Barciszewska et al.
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Outline

Text

Objective: Human brain tumors remain a diagnostic and therapeutic challenge for modern medicine. Despite many advanced tools and drugs, their detection is too late and the treatment ineffective. We describe a new, simple and reliable method for the molecular diagnosis of brain tumors. It is based on chromatographic quantitative determination of 5-methylcytosine (m5C) in relation to some damage products of DNA from tumor tissue and blood from brain tumor patients. The oxidative damage of DNA with reactive oxygen species leads to modification of DNA components, also m5C, which is an epigenetic regulator of gene expression. The analysis of total amount of m5C in DNA provides new information necessary to understand the carcinogenesis process, because it's a very sensitive marker of the oxidative stress. The aim of our work was to check the global m5C status of tissues from brain tumor patients.

Methods: We present the results of DNA analysis of 578 samples taken from brain tumor tissues, 186 of them combined with blood samples from the same patients. DNA was isolated, hydrolysed into nucleotides and separated on thin layer chromatography after labelling with [32P]ATP. Chromatograms were evaluated using phosphoimager and the amount of m5C was calculated as spot intensities ratio of [m5C/(m5C+C+T)] × 100 and expressed as R coefficient.

Results: The R values for the glioma patients show two crucial points - first around 1.0 (p<0.05) for patients with glioma grade III and the second around 0.4 (p<0.05) for glioblastoma multiforme. Therefore one can say that the R value of 1.0 clearly differentiates between low and high grade gliomas. For other tumor types (e.g. meningiomas, metastases) we’ve also found statistically significant differences. The comparison of R values for DNA from tumor tissue and peripheral blood cells taken from the same patients revealed clear correlation (r=0.88914, p<0.05). We have also tested DNA methylation for tissues stored in different conditions. That analysis showed the direct impact of material storage condition on DNA quality and m5C content.

Conclusions: 1. Global methylation analysis (R value) can be used for determination of malignancy of brain tumors. 2. There is a clear correlation between global DNA methylation in brain tissue and blood. 3. Sample storage method has an impact on the DNA damage and loss of methylation. 4. The method described is simple, reliable and easy to apply, using a limited amount of the starting material.