Integrative approach for prioritizing cancer genes in sporadic colon cancer
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE16125 | GEO | 2009/08/27
SECONDARY ACCESSION(S): PRJNA115015
REPOSITORIES: GEO
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Project description:The current multistep carcinogenesis models of colon cancer do not fully capture the genetic heterogeneity of the disease, which is additionally complicated by the presence of passenger and driver genetic alterations. The aim of the present study was to select in the context of this significant heterogeneity additional genes functionally related to colon cancer development. Methods: High-throughput copy number and gene expression data of 36 microsatellite stable sporadic colon cancers resected from patients of a single Institution characterized for mutations in APC, KRAS, TP53 and loss of 18q were analyzed. Genes whose expression correlated with the underlying copy number pattern were selected and their association with the above listed mutations and overall survival was evaluated. Results: Gain of 20q was strongly associated with TP53 mutation, and overall survival with alterations on 7p, 8p, 13q, 18q and 20q. An association with 18q loss and gain of 8q24 was also observed. New candidate genes with a potential role in colon cancer are PLCG1 on 20q, DBC1 on 8q21 and NDGR1 on 8p24. In addition an unexpected pattern of loss and mutability was found in the region upstream of KRAS gene. Conclusions: By integrating copy number alterations with gene expression and mutations in colon cancer associated genes we have developed a strategy that identifies previously known molecular features and additional players in the molecular landscape of colon cancer. A total of 48 sporadic colon cancer samples were analyzed by Affymetrix Mapping 250K Nsp SNP Arrays and 36 of them were also analyzed by Affymetrix Human Exon 1.0 ST Array [transcript (gene) version]. Short summary: Expression data was correlated to copy number data to identify genes whose expression was induced by copy number changes. Gene dosage candidates were then evaluated for their association with gene mutation status of APC, KRAS and TP53, loss of heterozigosity of 18q and overall survival. Long summary: Raw intensity .CEL files of the SNP arrays were processed with Chromosome Copy Number Analysis Tool (v.1.5.6 Affymetrix, Santa Clara, CA) to identify chromosomal gains and losses. Forty eight normal samples from the HapMap project supplied by Affymetrix were used as an un-paired reference set [http://www.affymetrix.com/support/technical/sample_data/500k_data.affx]. All genomic coordinates of the SNP array probes were mapped to the Human Mar. 2006 assembly the UCSC genome browser. Raw intensity .CEL files of the exon arrays were processed with the Robust Multi-Array implementation of Affymetrix Power Tools (v.1.8.6) using the core set of features (22011 probesets). All plots and analysis steps following this processing were done using the R programming language version 2.9.0Bioconductor packages. The identification of statistically significant segments of aberration in the copy number data was performed using the default parameters of the KC-SMART algorithm and 1000 permutations (KCsmart v.2.2.0). The identification and annotation of genes within each aberrant segment was performed using biomaRt v.2.0.0. The list of genes was further annotated by using the cancerGenes resource, Cancer Gene Census and the list of breast and colon CAN genes listed in Wood et al. The genomic landscapes of human breast and colorectal cancers. Science 2007;318:1108-1113. Gene dosage effects across 36 samples for which gene expression and copy number data was available was assessed by evaluating the Spearman correlation of the raw continuous copy number (log-ratios) expression (log-intensity) for each genomic region surrounding each gene falling within the segments identified by KC-SMART. Prior to performing this task, to reduce the total number of correlation tests to perform, we filtered the gene expression dataset by removing all entries having no Gene Symbol annotation 17291 probesets and half the remaining dataset exhibiting the lowest variance resulting in 8645 probesets. Category package version 2.10.0 was used to apply a linear model-based test to detect enrichment of systematic high correlation in specific chromosomal bands taking into consideration the hierarchical structure of the bands. Gene expression class comparisons and survival analysis of the selected gene dosage candidates were performed using two sample t-tests and Cox proportional hazards regression. P-value adjustment of the correlation tests and the gene expression associations was performed using the step-up false discovery rate (FDR) controlling procedure of Benjamini and Hochberg. Raw data, supplementary methods and figures supplied as reproducible documentation (Sweave file) available from http://pierotti.group.ifom-ieo-campus.it/suppl/crc.html.
2010-04-10 | E-GEOD-16125 | biostudies-arrayexpress
Project description:Li-Fraumeni syndrome (LFS) is a rare, clinically and genetically heterogeneous inherited cancer syndrome. Most cases are due to mutations in TP53. CHK2 is a minor predisposing locus; we recently mapped a third locus to 1q23. In both TP53 and non-TP53 LFS, there is evidence for risk heterogeneity within and between kindreds, suggesting additional risk modifiers. Using BAC- and SNP-based microarrays, we performed genomic profiling of primary soft tissue sarcomas, osteosarcomas and matching constitutive samples of 10 LFS patients (6 with and 4 without TP53 mutations), to identify genome-wide patterns of copy number changes and loss-of-heterozygosity (LOH). Our complementing global approaches revealed several interesting patterns for TP53 and non-TP53 LFS tumors, including positive (1q/7, 3p/15, 4q/9q, 8q/19p, 9p/10q, 13/14 and 15q/18q) and negative (2q/9q, 3q/14q and 4q/6q) associations between chromosomal regions. The region containing the oncogene TWIST1 (7p21.1) was the most common gain independent of TP53 status and tumor type, while LOH of 8q11.2 with the tumor suppressor ST18 was the only region exclusively associated with non-TP53 soft tissue sarcomas. We resequenced known mutations in BRAF, KRAS and NRAS and identified somatic NRAS mutations in 2 of 10 tumors. TP53 and non-TP53 LFS tumors shared multiple hits in genes of the p53 and overlapping pathways. Although common dogma in cancer genetics holds that multiple hits in the same pathway are redundant and thus unlikely, we show that different combinations of genetic alterations in both TP53 and non-TP53 LFS tumors appear to act together in the p53 network in LFS tumorigenesis Keywords: Comparative genomic hybridization Using the Spectral Genomics dye-swap BAC arrays we studied 10 Li Fraumeni syndrome tumor cases
2008-07-16 | E-GEOD-8798 | biostudies-arrayexpress
Project description:Li-Fraumeni syndrome (LFS) is a rare, clinically and genetically heterogeneous inherited cancer syndrome. Most cases are due to mutations in TP53. CHK2 is a minor predisposing locus; we recently mapped a third locus to 1q23. In both TP53 and non-TP53 LFS, there is evidence for risk heterogeneity within and between kindreds, suggesting additional risk modifiers. Using BAC- and SNP-based microarrays, we performed genomic profiling of primary soft tissue sarcomas, osteosarcomas and matching constitutive samples of 10 LFS patients (6 with and 4 without TP53 mutations), to identify genome-wide patterns of copy number changes and loss-of-heterozygosity (LOH). Our complementing global approaches revealed several interesting patterns for TP53 and non-TP53 LFS tumors, including positive (1q/7, 3p/15, 4q/9q, 8q/19p, 9p/10q, 13/14 and 15q/18q) and negative (2q/9q, 3q/14q and 4q/6q) associations between chromosomal regions. The region containing the oncogene TWIST1 (7p21.1) was the most common gain independent of TP53 status and tumor type, while LOH of 8q11.2 with the tumor suppressor ST18 was the only region exclusively associated with non-TP53 soft tissue sarcomas. We resequenced known mutations in BRAF, KRAS and NRAS and identified somatic NRAS mutations in 2 of 10 tumors. TP53 and non-TP53 LFS tumors shared multiple hits in genes of the p53 and overlapping pathways. Although common dogma in cancer genetics holds that multiple hits in the same pathway are redundant and thus unlikely, we show that different combinations of genetic alterations in both TP53 and non-TP53 LFS tumors appear to act together in the p53 network in LFS tumorigenesis Keywords: Comparative genomic hybridization
2008-07-16 | GSE8798 | GEO
Project description:To determine the pattern of copy number alterations that characterizes Crohn’s disease associated colorectal carcinomas (CD-CRCs), we performed array-based comparative genomic hybridization (aCGH) of CD-CRCs. As control group, we used histomorphologically similar sporadic mucinous colorectal adenocarcinomas. To gain insight into the dynamics of copy number alterations in CD associated colorectal tumor development, we additionally analyzed non-dysplastic, i.e., normal or inflamed, mucosa samples and dysplastic lesions from CD-CRC patients by aCGH. This revealed the gain of chromosome arm 5p as a distinctive feature of CD related colorectal carcinogenesis, while the overall pattern of copy number changes in CD-CRC was similar to sporadic mucinous CRC, including gains of chromosomes and chromosome arms 7, 8, 13 and 20q, and losses of 5q, 8p, 17p and 18q.
2018-06-30 | GSE113015 | GEO
Project description:AML with complex karyotype (CK-AML) is characterized by a high frequency of TP53 alteration (loss and/or mutation). TP53-altered CK-AML were characterized by a higher degree of genomic complexity (aberrations per case, 14.30 vs. 6.16; P<.0001), and by a higher frequency of specific copy number alterations, such as -5/5q-, -7/7q-, -16/16q-, -18/18q-, +1/+1p, and +11/+11q/amp11q13~25; among CK-AML, TP53-altered more frequently exhibited a monosomal karyotype (MK). Patients with TP53 alterations were older and had significantly lower complete remission rates, inferior event-free, relapse-free, and overall survival. In multivariable analysis for overall survival, TP53 alterations, white blood cell counts, and age were the only significant factors. In conclusion, TP53 is the most frequently known altered gene in CK-AML. TP53 alterations are associated with older age, genomic complexity, specific DNA copy number alterations, MK, and dismal outcome. In multivariable analysis, TP53 alteration is the most important prognostic factor in CK-AML, outweighing all other variables, including the MK category.
2012-08-27 | GSE34542 | GEO
Project description:Fallopian tube carcinoma (FTC) is a rare, poorly studied and aggressive cancer, associated with poor survival. Since tumorigenesis is related to acquisition of genetic changes, we used genome-wide array CGH to analyze copy number aberrations occurring in FTC in order to obtain a better understanding of FTC carcinogenesis and to identify prognostic events and targets for therapy. We used arrays of 2464 genomic clones, providing ~1.4 Mb resolution across the genome to quantitatively map genomic DNA copy number aberrations from fourteen FTC onto the human genome sequence. All tumors showed a high frequency of copy number aberrations with recurrent gains on 3q, 6p, 7q, 8q, 12p, 17q, 19 and 20q, and losses involving chromosomes 4, 5q, 8p, 16q, 17p, 18q and X. Recurrent regions of amplification included 1p34, 8p11-q11, 8q24, 12p, 17p13, 17q12-q21, 19p13, 19q12-q13 and 19q13. Candidate, known oncogenes mapping to these amplicons included CMYC (8q24), CCNE1 (19q12-q21) and AKT2 (19q13), whereas PIK3CA and KRAS, previously suggested to be candidate driver genes for amplification mapped outside copy number maxima on 3q and 12p, respectively. The FTC were remarkably homogeneous, with some recurrent aberrations occurring in more than 70% of samples, which suggests a stereotyped pattern of tumor evolution. Keywords: array CGH, CCNE1, AKT2, Fallopian tube cancer
2007-03-06 | GSE7180 | GEO
Project description:We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss (SCNAs). The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar SCNA patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number of alterations. Genomically, colorectal and metastatic liver tumors were very similar. However, in a subgroup of patients, there were genetic variations in liver metastases in the loss of DNA mismatch repair genes. Copy number analysis of Affymetrix CytoScanHD arrays was performed for 15 primary colorectal carcinoma and 15 samples of their matched liver metastases. 15 normal samples prepared from each of the patient was used as the reference for the study. Nexus Copy number 6.1 software was used for somatic copy number alteration analysis.
2014-03-01 | E-GEOD-53799 | biostudies-arrayexpress
Project description:Never-smoker lung adenocarcinoma (NSLA) is prevalent in Asian populations and even more in women. Since epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) fusions are major alterations found in NSLA, studies have focused on NSLA with EGFR and ALK alteration (EA), but not for NSLA without EGFR and ALK alteration (NENA). To reveal the proteogenomic landscape of NENA, we selected 101 NSLA tissues without EGFR and ALK by targeted sequencing of 1597 FFPE samples, and performed multiomics analyses including whole genome, transcriptome, methylation EPIC array, total proteome, and phosphoproteome. Genome analysis revealed that TP53 (25%), KRAS (22%), ROS1 fusion (13%), SETD2 (11%), and ERRB2 (9%) were the most frequently mutated genes in NENA. Proteogenomic impact analysis found that STK11 and ERBB2 somatic mutations had more profound effects on cancer-associated genes in NENA. From DNA copy number alteration analysis, we identified 22 prognostic proteins whose expression was controlled through transcriptome from copy number alterations Intriguingly, from gene set enrichment analysis, estrogen signaling emerged as the key pathway activated in NENA compared with EA. Evidence from multiomics analysis including copy number gains in chromosomes 14 and 21, STK11 mutation, and DNA hypomethylation of LLGL2 and ST14, also supported the increased estrogen signaling. Finally, the saracatinib, an Src inhibitor, was suggested as a potential drug for targeting activated estrogen signaling in NENA. Taken together, the proteogenomic landscape for NENA from this study will enhance our understanding of the etiology of NSLA.
2024-03-12 | PXD033360 | Pride
Project description:We applied whole-genome single nucleotide polymorphism (SNP) arrays to define a comprehensive genetic profile of 23 esophageal adenocarcinoma (EAC) primary tumor biopsies based on loss of heterozygosity (LOH) and DNA copy number changes. Alterations were common, averaging 97 (range 23-208) per tumor. LOH and gains averaged 33 (range 3-83) and 31 (range 11-73) per tumor, respectively. Copy neutral LOH events averaged 27 (range 7-57) per EAC. We noted 126 homozygous deletions (HDs) across the EAC panel (range 0-11 in individual tumors). Frequent HDs within FHIT (17/23), WWOX (8/23) and DMD (6/23) suggest a role for common fragile sites or genomic instability in EAC etiology. HDs were also noted for known tumor suppressor genes (TSGs) including: CDKN2A, CDKN2B, SMAD4 and GALR1, and identified PDE4D and MGC48628 as potentially novel TSGs. All tumors showed LOH for most of chromosome 17p, suggesting that TSGs other than TP53 maybe targeted. Frequent gains were noted around MYC (13/23), BCL9 (12/23), CTAGE1 (14/23) and ZNF217 (12/23). Thus, we have confirmed previous reports indicating frequent changes to FHIT, CDKN2A, TP53 and MYC in EAC and identified additional genes of interest. Meta analysis of previous genome-wide EAC studies together with the data presented here, highlighted consistent regions of gain on 8q, 18q and 20q, and multiple LOH regions on 4q, 5q, 17p and 18q, suggesting that more than one gene may be targeted on each of these chromosome arms. The focal gains and deletions documented here are a step towards identifying the key genes involved in EAC development. Keywords: High Density SNP array Here we use Illumina 317K whole-genome single-nucleotide polymorphism arrays to define a comprehensive allelotype of melanoma based on loss of heterozygosity (LOH) and copy number changes in a panel of 23 esophageal adenocarcinoma (EAC) primary tumor biopsies. Each EAC was paired to normal squamous biopsy from 40328 (GSM266078) to generate the log_R_ratio.
2008-06-01 | E-GEOD-10506 | biostudies-arrayexpress
Project description:We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss (SCNAs). The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar SCNA patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number of alterations. Genomically, colorectal and metastatic liver tumors were very similar. However, in a subgroup of patients, there were genetic variations in liver metastases in the loss of DNA mismatch repair genes.
2014-03-01 | GSE53799 | GEO