Promoter DNA Methylation Pattern Identifies Prognostic Subgroups in Childhood T-Cell Acute Lymphoblastic Leukemia

Magnus Borssén, Lars Palmqvist, Kristina Karrman, Jonas Abrahamsson, Mikael Behrendtz, Jesper Heldrup, Erik Forestier, Göran Roos, Sofie Degerman, Carmen J. Marsit
2013 PLoS ONE  
Treatment of pediatric T-cell acute lymphoblastic leukemia (T-ALL) has improved, but there is a considerable fraction of patients experiencing a poor outcome. There is a need for better prognostic markers and aberrant DNA methylation is a candidate in other malignancies, but its potential prognostic significance in T-ALL is hitherto undecided. Design and Methods: Genome wide promoter DNA methylation analysis was performed in pediatric T-ALL samples (n = 43) using arrays covering .27000 CpG
more » ... . Clinical outcome was evaluated in relation to methylation status and compared with a contemporary T-ALL group not tested for methylation (n = 32). Results: Based on CpG island methylator phenotype (CIMP), T-ALL samples were subgrouped as CIMP+ (high methylation) and CIMP2 (low methylation). CIMP2 T-ALL patients had significantly worse overall and event free survival (p = 0.02 and p = 0.001, respectively) compared to CIMP+ cases. CIMP status was an independent factor for survival in multivariate analysis including age, gender and white blood cell count. Analysis of differently methylated genes in the CIMP subgroups showed an overrepresentation of transcription factors, ligands and polycomb target genes. Conclusions: We identified global promoter methylation profiling as being of relevance for subgrouping and prognostication of pediatric T-ALL.
doi:10.1371/journal.pone.0065373 pmid:23762353 pmcid:PMC3675104 fatcat:n3cytc5cezfk3kfldbecju2e3e