Epigenetic regulation of CD44in Hodgkin and non-Hodgkin lymphoma

BMC Cancer

Research Article

Hans G Drexler¹  Hilmar Quentmeier¹  Julia Romani¹  Björn Schneider¹  Margarete Zaborski¹  Sonja Eberth¹  Reiner Siebert²  Andreas Rosenwald³  Elena M Hartmann³ 

[1] DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany;Institute of Human Genetics, Christian-Albrechts University, Kiel, Germany;Institute of Pathology, University of Würzburg, Würzburg, Germany;

关键词: Follicular Lymphoma;    Hodgkin Lymphoma;    Mantle Cell Lymphoma;    Burkitt Lymphoma;    Anaplastic Large Cell Lymphoma;   

DOI  :  10.1186/1471-2407-10-517

 received in 2010-05-19, accepted in 2010-09-29,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundEpigenetic inactivation of tumor suppressor genes (TSG) by promoter CpG island hypermethylation is a hallmark of cancer. To assay its extent in human lymphoma, methylation of 24 TSG was analyzed in lymphoma-derived cell lines as well as in patient samples.MethodsWe screened for TSG methylation using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in 40 lymphoma-derived cell lines representing anaplastic large cell lymphoma, Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Hodgkin lymphoma and mantle cell lymphoma (MCL) as well as in 50 primary lymphoma samples. The methylation status of differentially methylated CD44 was verified by methylation-specific PCR and bisulfite sequencing. Gene expression of CD44 and its reactivation by DNA demethylation was determined by quantitative real-time PCR and on the protein level by flow cytometry. Induction of apoptosis by anti-CD44 antibody was analyzed by annexin-V/PI staining and flow cytometry.ResultsOn average 8 ± 2.8 of 24 TSG were methylated per lymphoma cell line and 2.4 ± 2 of 24 TSG in primary lymphomas, whereas 0/24 TSG were methylated in tonsils and blood mononuclear cells from healthy donors. Notably, we identified that CD44 was hypermethylated and transcriptionally silenced in all BL and most FL and DLBCL cell lines, but was usually unmethylated and expressed in MCL cell lines. Concordant results were obtained from primary lymphoma material: CD44 was not methylated in MCL patients (0/11) whereas CD44 was frequently hypermethylated in BL patients (18/29). In cell lines with CD44 hypermethylation, expression was re-inducible at mRNA and protein levels by treatment with the DNA demethylating agent 5-Aza-2'-deoxycytidine, confirming epigenetic regulation of CD44. CD44 ligation assays with a monoclonal anti-CD44 antibody showed that CD44 can mediate apoptosis in CD44+ lymphoma cells. CD44 hypermethylated, CD44- lymphoma cell lines were consistently resistant towards anti-CD44 induced apoptosis.ConclusionOur data show that CD44 is epigenetically regulated in lymphoma and undergoes de novo methylation in distinct lymphoma subtypes like BL. Thus CD44 may be a promising new epigenetic marker for diagnosis and a potential therapeutic target for the treatment of specific lymphoma subtypes.

【 授权许可】

CC BY   
© Eberth et al; licensee BioMed Central Ltd. 2010