Copy number alterations of 103 hepatocellular carcinomas with hepatitis C virus etiology
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ABSTRACT: To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis
Project description:To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including 'Wnt-CTNNB1', 'proliferation' and 'nterferon-related' gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Experiment Overall Design: 91 hepatocellular carcinomas were obtained at the time of surgical resection or orthotopic transplantation.
Project description:To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis 103 hepatocellular carcinomas and 95 adjacent cirrhotic, non-tumoral liver tissue were obtained at the time of surgical resection of orthotopic transplantation.
Project description:To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis
Project description:Adenoid cystic carcinoma (AAC) is a rare but distinctive tumor. Array comparative genomic hybridization (CGH) has been applied for detecting chromosomal copy number alterations in seventeen frozen salivary or pulmonary ACCs samples. There were recurrent gains at 1p36, 6p21, 16q24, 17q21, and 22q11-13, and recurrent losses at 1p35, 6q22, 8q12-13, 9p21, 12q12-13, and 17p11-13. The minimal common regions (MCRs) of these alterations contained several well-known cancer genes, including TP53, CDKN2A/CDKN2B, SKI, CDK10, and VEGF. CDK10 was the only oncogene that localized to the MCR of gain at 16q24.1-24.3. In addition, we identified LIMA1 as the sole putative tumor suppressor gene residing in the MCR of deletion at 12q12q12-13.2. Among well defined and narrow, but unique alterations, there were gains harboring MDM2, cyclin D1, and KIT, as well as one loss involving the hsa-mir-124a-2 miRNA. Using immunohistochemistry, we found abnormal protein expression in the cases with gain of cyclin D1 or MDM2. In conclusion, the majority of previously reported chromosomal copy number alterations are found using array CGH in this small cohort. The suspicion that genes such as TP53, CDKN2A/CDKN2B, and VEGF might play a role in ACC, is strengthened by our results. CDK10 and LIMA1 emerge from our analysis as candidate cancer genes
Project description:Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected a total of 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20% of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5%) and 17p13.1 (2.5%) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains, which includes ETS1 and FLI1 genes. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.
Project description:Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected a total of 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20% of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5%) and 17p13.1 (2.5%) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains, which includes ETS1 and FLI1 genes. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.
Project description:AIMS: HER2 testing of invasive breast cancer by in-situ hybridisation guides therapy decisions. Probing HER2 and cen17 simultaneously is supposed to reveal both a potential HER2 gene amplification and polysomy 17. However, a considerable number of breast cancer patients with quasi polysomy 17 are considered "equivocal" which is diagnostically meaningless. Moreover, patients with equivocal / false polysomic tumours are prevented from a potentially beneficial anti-HER2 treatment. Here we evaluated the RAI1, D17S122, and TP53 hybridisation markers to reliably indicate true polysomy and to accurately reclassify equivocal samples as HER2-positive. METHODS AND RESULTS: Samples with (n = 82) and without (n = 52) increased cen17 copy numbers and 78 evidently HER2-amplified specimens were analysed using dual and triple marker hybridisation probes. Selected putative polysomic samples were subjected to array-based comparative genomic hybridisation. We found that 37.8% samples with putative polysomy 17 did not show any gain in RAI1, D17S122, or TP53. Accordingly, aCGH revealed evidence for the presence of HER2/cen17 coamplification rather than for true polysomy in those cases. Reflex testing using alternate 17p markers reclassified up to 56.3% equivocal cases as HER2-positive and the combined assessment of a 17p and 17q locus allows the differentiation of true vs. false polysomy. CONCLUSIONS: An increased cen17 copy number does not necessarily reflect polysomy and reflex testing facilitates the reclassification of "equivocals". Nevertheless, the prognostic and predictive value of a HER2/cen17 coamplification versus HER2 gene amplification alone must still be prospectively evaluated. This article is protected by copyright. All rights reserved.
Project description:Fifty-one breast tumors were profiled for copy-number alterations with the high-resolution Affymetrix 500K Mapping Array. Combined analysis of the prevalence and amplitude of copy-number alterations defined regions of recurrent gain or loss. Gains were most frequently observed on chromosomes 1, 8, 10, 11, 13, 15, 17, and 20. Losses were most frequent on chromosomes 3, 6, 11, 13, 14, 16, and 17. Compared with previous lower-resolution data, our analysis provided significantly more precise boundaries for frequently altered regions, greatly reducing the number of potential alteration-driving genes. Keywords: Mapping Array
Project description:To elucidate the pathogenesis of rhabdomyosarcoma (RMS), particularly for different subgroups, we performed a SNP array-based copy number analysis of 46 RMS specimens from primary cases with ERMS (N = 21), ARMS (N = 14), unclassified RMS (N = 1), and RMS of unknown histology (N = 3) together with 7 RMS-derived cell lines. The ERMS subtype was characterized by hyperploidy and was significantly associated with gains of chromosomes 2, 8, and 12, whereas majority of ARMS cases exhibited near-diploid copy number profiles. Recurrent loss of heterozygosity (LOH) of chromosomes 3 (28.6%) and 15q (35.7%) was detected in ARMS. Uniparental disomy/polysomy of 11p was commonly found in both tumor types. Focal gains/amplifications were associated mostly with PAX3-FOXO1 (5/10) or PAX7-FOXO1 (6/6) fusions, but novel amplified regions were also found, including the IRS2 in 2 ARMS. Gain of 13q was significantly associated with good patient outcome in ERMS. These findings not only illustrate genetic differences between ARMS and ERMS but also provide novel insights into the pathogenesis of RMS. Copy number analysis of Affymetrix 50K/250K SNP arrays was performed for 46 RMS samples.