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High-resolution copy number analysis of medulloblastoma

ABSTRACT: We used high-resolution SNP genotyping to identify regions of genomic gain and loss in the genome of 212 medulloblastomas, a malignant pediatric brain tumor. Focal amplifications of fifteen known oncogenes and focal deletions of twenty known tumor suppressor genes (TSG) were revealed, most not previously implicated in medulloblastoma. Importantly, we identified novel amplifications and homozygous deletions, including recurrent, mutually exclusive, highly focal genetic events in genes targeting histone lysine methylation, particularly histone 3, lysine 9 (H3K9). Post-translational modification of histone proteins is critical for regulation of gene expression, can participate in determining stem cell fates, and has been implicated in carcinogenesis. Consistent with our genetic data, restoration of expression of genes controlling H3K9 methylation greatly diminishes proliferation of medulloblastoma in vitro. Copy number aberrations of genes with critical roles in writing, reading, removing, and blocking the state of histone lysine methylation, particularly H3K9, suggest that defective control of the histone code contributes to the pathogenesis of medulloblastoma. Keywords: Affymetrix SNP array

ORGANISM(S): Homo sapiens

PROVIDER: GSE14437 | GEO | 2009/04/15

SECONDARY ACCESSION(S): PRJNA111773

REPOSITORIES: GEO

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High-resolution copy number analysis of medulloblastoma

Project description:We used high-resolution SNP genotyping to identify regions of genomic gain and loss in the genome of 212 medulloblastomas, a malignant pediatric brain tumor. Focal amplifications of fifteen known oncogenes and focal deletions of twenty known tumor suppressor genes (TSG) were revealed, most not previously implicated in medulloblastoma. Importantly, we identified novel amplifications and homozygous deletions, including recurrent, mutually exclusive, highly focal genetic events in genes targeting histone lysine methylation, particularly histone 3, lysine 9 (H3K9). Post-translational modification of histone proteins is critical for regulation of gene expression, can participate in determining stem cell fates, and has been implicated in carcinogenesis. Consistent with our genetic data, restoration of expression of genes controlling H3K9 methylation greatly diminishes proliferation of medulloblastoma in vitro. Copy number aberrations of genes with critical roles in writing, reading, removing, and blocking the state of histone lysine methylation, particularly H3K9, suggest that defective control of the histone code contributes to the pathogenesis of medulloblastoma. Keywords: Affymetrix SNP array Genomic DNA isolated from fresh frozen primary human medulloblastomas and medulloblastoma cell lines were subjected to SNP genotyping using either Affymetrix 100K or 500K GeneChip Mapping array sets for the purpose of obtaining genome-wide copy number and LOH profiles.

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