DNA methylation profiling in primary Diffuse Large B cell Lymphoma (DLBCL) and normal Germinal Center B Cells

ABSTRACT: Diffuse Large B-Cell Lymphoma (DLBCL) is the most common aggressive form of non-Hodgkin lymphoma with variable biology and clinical behavior. The current classification does not fully explain the biological and clinical heterogeneity of DLBCLs. In this study we carried out genome-wide DNA methylation profiling of 140 DLBCL samples and 10 normal germinal center B-cells (NGCBs) using the HELP assay and hybridization to a custom Roche NimbleGen promoter array. We defined methylation disruption as a main epigenetic event in DLBCLs and designed a method for measuring the methylation variability of individual cases. We then used a novel approach for unsupervised hierarchical clustering based on the extent of DNA methylation variability. This approach identified 6 clusters (A-F). The extent of methylation variability was associated with survival outcomes, with significant differences in overall and progression-free survival. The novel clusters are characterized by disruption of specific biological pathways like cytokine-mediated signaling, ephrin signaling and pathways associated with apoptosis and cell cycle regulation. In a subset of patients, we profiled gene expression and genomic variation to investigate their interplay with methylation changes. This study is the first to identify novel epigenetic clusters of DLBCLs and their aberrantly methylated genes, molecular associations and survival. DNA methylation profiling in 140 primary denovo Diffuse Large B cell Lymphoma (DLBCL) samples from patients that had undergone R-CHOP chemotherapy and 10 purified normal Germinal Center B Cells

ORGANISM(S): Homo sapiens

SUBMITTER: Nyasha Chambwe 

PROVIDER: E-GEOD-54200 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress