Project description:Splenic marginal zone lymphoma (SMZL) is an indolent B-cell lymphoproliferative disorder characterised by 7q32 deletion, but the target genes of this deletion remain unknown. In order to elucidate the genetic target of this deletion, we performed an integrative analysis of the genetic, epigenetic, transcriptomic and miRNomic data. High resolution array comparative genomic hybridization of 56 cases of SMZL delineated a minimally deleted region (2.8Mb) at 7q32, but showed no evidence of any cryptic homozygous deletion or recurrent breakpoint in this region. Integrative transcriptomic analysis confirmed significant under-expression of a number of genes in this region in cases of SMZL with deletion, several of which showed hypermethylation. In addition, a cluster of 8 miRNA in this region showed under-expression in cases with the deletion, and three (miR-182/96/183) were also significantly under-expressed (P <0.05) in SMZL relative to other lymphomas. Genomic sequencing of these miRNA and IRF5, a strong candidate gene, did not show any evidence of somatic mutation in SMZL. For methylation arrays. Epigenetic methylation analysis was performed using the Infinium Human Methylation 27 array (Illumina, San Diego, California, USA). The array contained 27,568 CpG islands within the proximal promoter regions of transcription start sites of 14,475 RefSeq genes, including 12,883 well annotated genes (NCBI CCDS database: Build 36). The methylation array was carried out in 12 SMZL (6 cases with 7q deletion), 6 follicular lymphomas (FL) and 6 mantle cell lymphomas (MCL) as per the manufacturer’s instructions. Briefly, 2μg genomic DNA extracted from frozen tissues with >70% tumour cells was bisulphite modified using the EZ DNA Methylation Kit (Zymo Research Corporation). Bisulphite modified DNA was then amplified using the MSM master mix (Illumina) and incubated at 37oC for 22 hours. Amplified DNA was then fragmented and hybridised to BeadChips in an Illumina Hybridisation Oven at 48oC for 18 hours. Following hybridisation, single base extension of hybridised DNA using hapten labelled bases was performed. Staining was then developed using immunochemical stains catalysed by the haptens, and the arrays washed. The chips were scanned using the BeadArray™ Reader (Illumina) and the BeadScan™ software (Illumina) using the Infinium Methylation Scan setting. The scanned data was then analysed in GenomeStudio™ (Illumina) using the Methylation analysis module.
Project description:This SuperSeries is composed of the following subset Series: GSE35424: methylation analysis was carried out on 12 SMZL, 6 MCL and 6 FL cases by the Cambridge group using Illumina Infinium Human Methylation 27 Array GSE35425: Oligo aCGH on 21 SMZL cases were carried out by the Cambridge group using the Agilent Custom 2Kb resolution Oligo aCGH GSE35426: Gene expression profiling was carried out on 14 SMZL, 5 FL and 5 MCL cases using the Affymetrix HG-U133plus2 gene expression microarrays by the Cambridge group Splenic marginal zone lymphoma (SMZL) is an indolent B-cell lymphoproliferative disorder characterised by 7q32 deletion, but the target genes of this deletion remain unknown. In order to elucidate the genetic target of this deletion, we performed an integrative analysis of the genetic, epigenetic, transcriptomic and miRNomic data. High resolution array comparative genomic hybridization of 56 cases of SMZL delineated a minimally deleted region (2.8Mb) at 7q32, but showed no evidence of any cryptic homozygous deletion or recurrent breakpoint in this region. Integrative transcriptomic analysis confirmed significant under-expression of a number of genes in this region in cases of SMZL with deletion, several of which showed hypermethylation. In addition, a cluster of 8 miRNA in this region showed under-expression in cases with the deletion, and three (miR-182/96/183) were also significantly under-expressed (P <0.05) in SMZL relative to other lymphomas. Genomic sequencing of these miRNA and IRF5, a strong candidate gene, did not show any evidence of somatic mutation in SMZL. For aCGH, 21 cases were done under accession number GSE35425. 21 fresh frozen splenic samples from patients with SMZL were hybridized against a reference control of pooled PBMC genomic DNA from 10 normal subjects. High-resolution oligonucleotide analysis of copy number variations in splenic marginal zone lymphoma (SMZL) in regions of recurrent alteration. Regions included on the array: 7q (2k resolution) and regions of interest on chromosomes 3q, 6q and 9q at 12k resolution. For gene expression microarrays, 24 cases were done under accession number GSE35426. A total of 48 cases of SMZL (including 15 with 7q deletion) were analysed using the Affymetrix HG-U133 Plus 2.0 platform (Affymetrix, Santa Clara, California, USA). Arrays were performed according to the manufacturer’s instructions. Briefly, RNA was extracted from snap frozen tissues with >70% tumour cells using the RNEasy extraction kit (Qiagen) and subjected to DNAse treatment (Turbo DNAse kit, Ambion). RNA integrity was assessed using an Agilent 2100 Bioanalyzer. cDNA synthesis was carried out with 2ug RNA using the GeneChip® One-Cycle cDNA Synthesis Kit (Affymetrix), followed by in vitro transcription with biotin-labelled nucleotides using GeneChip® IVT Labeling Kit. Biotinylated cRNA was purified and hybridized to the Affymetrix HG-U133 Plus 2.0 chips in a GeneChip® Hybridisation Oven 640 at 45oC for 14 hours. The arrays were then washed and stained using the Fluidics station 450 system (Affymetrix). The arrays were scanned using the Affymetrix GeneArray® Scanner 3000. Hybridisation and labelling controls were included according to the manufacturer’s instructions, and quality control analysis of microarrays was performed to published standards. For methylation arrays, 24 cases were done under accession number GSE35424. Epigenetic methylation analysis was performed using the Infinium Human Methylation 27 array (Illumina, San Diego, California, USA). The array contained 27,568 CpG islands within the proximal promoter regions of transcription start sites of 14,475 RefSeq genes, including 12,883 well annotated genes (NCBI CCDS database: Build 36). The methylation array was carried out in 12 SMZL (6 cases with 7q deletion), 6 follicular lymphomas (FL) and 6 mantle cell lymphomas (MCL) as per the manufacturer’s instructions. Briefly, 2μg genomic DNA extracted from frozen tissues with >70% tumour cells was bisulphite modified using the EZ DNA Methylation Kit (Zymo Research Corporation). Bisulphite modified DNA was then amplified using the MSM master mix (Illumina) and incubated at 37oC for 22 hours. Amplified DNA was then fragmented and hybridised to BeadChips in an Illumina Hybridisation Oven at 48oC for 18 hours. Following hybridisation, single base extension of hybridised DNA using hapten labelled bases was performed. Staining was then developed using immunochemical stains catalysed by the haptens, and the arrays washed. The chips were scanned using the BeadArray™ Reader (Illumina) and the BeadScan™ software (Illumina) using the Infinium Methylation Scan setting. The scanned data was then analysed in GenomeStudio™ (Illumina) using the Methylation analysis module. **Samples from Series GSE35278 and GSE35348 was also used in this study: GSE35278: Oligo aCGH on 35 SMZL cases were carried out by the Mayo clinic group using the Agilent Oligo aCGH 244A platform (6.4Kb resolution) GSE35348: Gene expression profiling was carried out by the Mayo clinic group on 24 SMZL cases using the Affymetrix HG-U133 plus2 gene expression microarrays
Project description:Splenic marginal zone lymphoma (SMZL) is an indolent B-cell lymphoproliferative disorder characterised by 7q32 deletion, but the target genes of this deletion remain unknown. In order to elucidate the genetic target of this deletion, we performed an integrative analysis of the genetic, epigenetic, transcriptomic and miRNomic data. High resolution array comparative genomic hybridization of 56 cases of SMZL delineated a minimally deleted region (2.8Mb) at 7q32, but showed no evidence of any cryptic homozygous deletion or recurrent breakpoint in this region. Integrative transcriptomic analysis confirmed significant under-expression of a number of genes in this region in cases of SMZL with deletion, several of which showed hypermethylation. In addition, a cluster of 8 miRNA in this region showed under-expression in cases with the deletion, and three (miR-182/96/183) were also significantly under-expressed (P <0.05) in SMZL relative to other lymphomas. Genomic sequencing of these miRNA and IRF5, a strong candidate gene, did not show any evidence of somatic mutation in SMZL. Keywords: Genome variation profiling by genome tiling array For aCGH. 21 fresh frozen splenic samples from patients with SMZL were hybridized against a reference control of pooled PBMC genomic DNA from 10 normal subjects. High-resolution oligonucleotide analysis of copy number variations in splenic marginal zone lymphoma (SMZL) in regions of recurrent alteration. Regions included on the array: 7q (2k resolution) and regions of interest on chromosomes 3q, 6q and 9q at 12k resolution.
Project description:Splenic marginal zone lymphomas (SMZL) are an uncommon type of B-cell non-Hodgkin’s lymphoma (NHL-B) in which no specific chromosomal translocations have been described. In contrast, the most frequent cytogenetic abnormality is the loss of the long arm of chromosome 7 (7q). Previous reports have located this loss in the 7q32 region. In order to better characterize the genomic imbalances in SMZL, molecular studies were carried out in 73 patients with SMZL. To gain insight into the mapping at 7q a tiling array was also used. Our results confirmed the presence of a new region of loss on chromosome 7 in these NHL.
Project description:Splenic marginal zone lymphomas (SMZL) are an uncommon type of B-cell non-Hodgkin’s lymphoma (NHL-B) in which no specific chromosomal translocations have been described. In contrast, the most frequent cytogenetic abnormality is the loss of the long arm of chromosome 7 (7q). Previous reports have located this loss in the 7q32 region. In order to better characterize the genomic imbalances in SMZL, molecular studies were carried out in 73 patients with SMZL. To gain insight into the mapping at 7q a tiling array was also used. Our results confirmed the presence of a new region of loss on chromosome 7 in these NHL. In order to better characterize the genomic imbalances in SMZL, molecular studies were carried out in 69 patients with SMZL.
Project description:Using high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Notably, deletion or uniparental disomy of chromosome 7q were detected in 39% of SMZLs but in only 9 of 170 (5%) mature B-cell lymphomas (p<10-6). The presence of unmutated IgVH genes, genomic complexity, 17p13-P53 deletion and 8q gain including MYC gene, but not 7q deletion, were correlated with shorter overall survival. Extensive mapping analyses narrowed down the commonly deleted region to 2.7 Mb. in 7q32.1-q32.2 from SND1 to COPG2 genes. High-throughput sequencing analysis of the 7q32 deleted segment in SMZL cells did not identify bi-allelic deletions, insertions or clear pathogenic mutations, but detected six single nucleotide changes in IRF5 (n=2), TMEM209 (n=2), CALU (n=1) and ZC3HC1 (n=1). Comparative expression analysis found that IRF5, TMEM209 and CALU genes had down-regulated expression in lymphomas with 7q32 deletion vs. non-deleted tumors. Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased cell proliferation and induced apoptosis. These results indicate that small deletions, insertions and/or point mutations inactivating genes within 7q32 are not common events in SMZL. Further studies are required to evaluate the putative role of IRF5 in SMZL pathogenesis.
Project description:Using high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Notably, deletion or uniparental disomy of chromosome 7q were detected in 39% of SMZLs but in only 9 of 170 (5%) mature B-cell lymphomas (p<10-6). The presence of unmutated IgVH genes, genomic complexity, 17p13-P53 deletion and 8q gain including MYC gene, but not 7q deletion, were correlated with shorter overall survival. Extensive mapping analyses narrowed down the commonly deleted region to 2.7 Mb. in 7q32.1-q32.2 from SND1 to COPG2 genes. High-throughput sequencing analysis of the 7q32 deleted segment in SMZL cells did not identify bi-allelic deletions, insertions or clear pathogenic mutations, but detected six single nucleotide changes in IRF5 (n=2), TMEM209 (n=2), CALU (n=1) and ZC3HC1 (n=1). Comparative expression analysis found that IRF5, TMEM209 and CALU genes had down-regulated expression in lymphomas with 7q32 deletion vs. non-deleted tumors. Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased cell proliferation and induced apoptosis. These results indicate that small deletions, insertions and/or point mutations inactivating genes within 7q32 are not common events in SMZL. Further studies are required to evaluate the putative role of IRF5 in SMZL pathogenesis.
Project description:Using high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Notably, deletion or uniparental disomy of chromosome 7q were detected in 39% of SMZLs but in only 9 of 170 (5%) mature B-cell lymphomas (p<10-6). The presence of unmutated IgVH genes, genomic complexity, 17p13-P53 deletion and 8q gain including MYC gene, but not 7q deletion, were correlated with shorter overall survival. Extensive mapping analyses narrowed down the commonly deleted region to 2.7 Mb. in 7q32.1-q32.2 from SND1 to COPG2 genes. High-throughput sequencing analysis of the 7q32 deleted segment in SMZL cells did not identify bi-allelic deletions, insertions or clear pathogenic mutations, but detected six single nucleotide changes in IRF5 (n=2), TMEM209 (n=2), CALU (n=1) and ZC3HC1 (n=1). Comparative expression analysis found that IRF5, TMEM209 and CALU genes had down-regulated expression in lymphomas with 7q32 deletion vs. non-deleted tumors. Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased cell proliferation and induced apoptosis. These results indicate that small deletions, insertions and/or point mutations inactivating genes within 7q32 are not common events in SMZL. Further studies are required to evaluate the putative role of IRF5 in SMZL pathogenesis.