Dataset Information

Frequent occurrence of deletions in primary mediastinal B-cell lymphoma

ABSTRACT: Primary mediastinal B-cell lymphoma (PMBCL) is a distinct subtype of diffuse large B-cell lymphoma. PMBCL has been previously studied with a variety of genomic techniques resulting in frequent detection of chromosomal gains; however, chromosomal losses have been rarely reported. This finding contrasts many other types of lymphoma, in which deletions are common. We hypothesize that segmental losses do exist but may have escaped detection by methods used in the previous studies. Using array comparative genomic hybridization to a tiling-resolution microarray encompassing the entire human genome, PMBCL samples were analyzed for genomic copy number alterations. Both gains and losses of chromosomal material were detected throughout the genome. These DNA copy number alterations were confirmed by quantitative real-time PCR. Recurrent chromosomal losses include a novel event at 1p13.1-p13.2 present in 42% of cases analyzed. We conclude that losses are present in the PMBCL genome. Given the similar frequency of losses to that of segmental gains of DNA, they are likely to play an important role in the pathogenesis of PMBCL. Keywords: array CGH, PMBCL

ORGANISM(S): Homo sapiens

PROVIDER: GSE7383 | GEO | 2007/08/15

SECONDARY ACCESSION(S): PRJNA100391

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Tumorigenic processes are understood to be driven by epi-/genetic and genomic alterations from single point mutations to chromosomal alterations such as insertions and deletions of nucleotides up to gains and losses of large chromosomal fragments including products of chromosomal rearrangements e.g. fusion genes and proteins. Overall comparisons of copy number alterations (CNAs) present in 48 clear cell renal cell carcinoma (ccRCC) genomes result in ratios of gene losses versus gene gains between 26 ccRCC Fuhrman malignancy grades G1 (ratio 1.25) and 20 G3 (ratio 0.58). Gene losses and gains of 15762 CNA genes are mapped to 795 chromosomal cytoband loci including 280 KEGG pathways. CNAs are classified according to their contribution to Fuhrman tumour gradings G1 and G3. Gene gains and losses turn out to be highly structured processes in ccRCC genomes enabling the subclassification and stratification of ccRCC tumours in a genome-wide manner. CNAs of ccRCC seem to start with common tumour related gene losses flanked by CNAs specifying Fuhrman grade G1 losses and CNA gains favouring grade G3 tumours. The appearance of recurrent CNA signatures implies the presence of causal mechanisms most likely implicated in the pathogenesis and disease-outcome of ccRCC tumours distinguishing lower from higher malignant tumours. Finally, the diagnostic quality of initial 201 genes (108 genes supporting G1 and 93 genes G3 phenotypes) are successfully validated on published Swiss data (GSE19949) leading to a restricted CNA gene set of 171 CNA genes of which 85 genes favour Fuhrman grade G1 and 86 genes Fuhrman grade G3. Regarding these gene sets overall survival decreases with the number of G3 related gene losses plus the total number of gene gains. CNA gene sets presented define an entry to a gene-directed and pathway-related functional understanding of ongoing copy number alterations within and between individual ccRCC tumours leading to CNA genes of prognostic and predictive value.

Dataset Information

Frequent occurrence of deletions in primary mediastinal B-cell lymphoma

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure