Abstracts (poster) - Wissenschaft Online

Sonja Röhrs, Julia Romani, Wilhelm Dirks, Hans G. Drexler, Hilmar Quentmeier
Methylation profiles of tumour suppressor genes in Hodgkin
and non-Hodgkin lymphoma cell lines
Epigenetic inactivation of tumour suppressor genes (TSGs) by promoter CpG island
methylation is frequently observed in neoplasia. It is generally agreed, that CpG island
hypermethylation profiles are specific for different tumour types. Therefore, the
methylation patterns of TSGs might prove useful in cancer diagnosis and indicative of
cellular drug responses. Here, we set out to elucidate whether the methylation profile of
TSGs would allow the classification of diverse lymphoma entities. We analysed the
methylation status of 24 different TSGs in combination with copy number changes.
Thirty-nine lymphoma cell lines were tested, representing Hodgkin lymphoma plus five
distinct subtypes of non-Hodgkin lymphoma. For this approach we used a methylationspecific
MLPA (Multiplex Ligation-dependent Probe Amplification) assay. Using
quantitative real time PCR, we confirmed transcriptional silencing of hypermethylated
TSGs, discovered by MLPA. We identified a group of TSGs, generally methylated or
deleted in all analysed lymphoma cell lines (e.g. CDH13, IGSF4, RARbeta). We also
found several TSGs, that were preferentially methylated in specific lymphoma subtypes
(e.g. CD44, CHFR, RASSF1A). Our results support methylation studies (e.g. for RARbeta
and RASSF1A) performed on primary lymphoma patient material 1,2 , confirming the
applicability of cell lines as model systems. This screening method, thus revealed
potential novel epigenetic markers for Hodgkin and non-Hodgkin lymphoma.
Literature
1 Murray P. G., Qiu G. H., Fu L. et al. (2004) Frequent epigenetic inactivation of the
RASSF1A tumor suppressor gene in Hodgkin´s lymphoma. Oncogene 23 (6): 1326-31.
2 Shi H., Guo J., Duff D. J., Rahmatpanah F. et al. (2007) Discovery of novel epigenetic
markers in non-Hodgkin´s lymphoma. Carcinogenesis 28, 1: 60-70.
contact:
Dr. Sonja Röhrs
DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Department of human and animal cell lines
sro07@dsmz.de
Inhoffenstr. 7B
38124 Braunschweig (Germany)