Mutational signatures of aflatoxin
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ABSTRACT:
PROVIDER: EGAS00001002490 | EGA |
REPOSITORIES: EGA
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Project description:Hepatocellular carcinoma (HCC) is a deadly disease, often unnoticed till the late stages, where treatment options become limited. Thus, there is a critical need to identify early biomarkers for detection of the developing HCC, as well as molecular pathways that would be amenable to therapeutic intervention. While efforts using human serum and tissues from late stage patients have been undertaken, progress has been limited. We have therefore explored the possibility of utilizing established mouse models for the discovery of biomarkers, as well as to understand in a systematic manner the molecular pathways that are progressively deregulated by the various etiological factors in contributing to HCC formation. As an initial effort, we have used the Hepatitis B surface antigen (HBsAg) transgenic mice as a hepatitis model, which have been exposed to aflatoxin B1 (AFB1). In this report, we present the initial findings from a extensive longitudinal study, which confirms the synergistic effect of both these etiological factors, with a gender bias towards male mice. Tumors from the mouse models were validated both histologically as well as by molecular transcriptome analysis by comparison with human HCCs. In addition, using these models, we have identified carnitine as a novel biomarker for HCC development, which was again validated using human HCC samples. Conclusion: This study therefore highlights the utility of these mouse models in identifying biomarkers for detection of human HCCs, as well as for the systematic analysis of molecular pathways that are affected by various etiological agents during the progression of HCC from an untransformed hepatocyte, which could provide novel options for targeted therapy. liver obtained from Mus musculus which was intraperitoneally injected with AFB/oil at Day 7 and sacrificed at 15 month age. We intend to compare molecular transcriptome analysis of mouse HCC with human HCCs.
2014-01-15 | E-GEOD-54054 | biostudies-arrayexpress
Project description:Chronic infections by hepatitis B virus (HBV) and hepatitis C virus (HCV) appear to be the most significant causes of hepatocellular carcinoma (HCC). Aberrant promoter methylation is known to be deeply involved in cancer, including HCC. In this study, we analyzed aberrant promoter methylation on genome-wide scale in 6 HCCs including 3 HBV-related and 3 HCV-related HCCs, 6 matched noncancerous liver tissues and 3 normal liver tissues by methylated DNA immunoprecipitation-on-chip analysis. Candidate genes with promoter methylation were detected more frequently in HCV-related HCC. Candidate genes methylated preferentially to HBV-related or HCV-related HCCs were detected and selected, and methylation levels of the selected genes were validated using 125 liver tissue samples, including 61 HCCs (28 HBV-related HCCs and 33 HCV-related HCCs) and matched 59 matched noncancerous livers, and 5 normal livers, by quantitative methylation analysis using MALDI-TOF mass spectrometry. Among analyzed genes, preferential methylation in HBV-related HCC was validated in 1 gene only. However, 15 genes were found methylated preferentially in HCV-related HCC, which was independent from age. Hierarchical clustering of HCC using these 15 genes stratified HCV-related HCC as a cluster of frequently methylated samples. The 15 genes included genes inhibitory to cancer-related signaling such as RAS/RAF/ERK and Wnt/b-catenin pathways. It was indicated that genes methylated preferentially in HCV-related HCC exist, and it was suggested that DNA methylation might play an important role in HCV-related HCC by silencing cancer-related pathway inhibitors. we analyzed aberrant promoter methylation in 6 HCC clinical samples (including 3 HBV-related HCCs and 3 HCV-related HCCs) and their matched noncancerous tissues on genome-wide scale by the method. Candidate regions of promoter methylation preferentially to HBV-related HCC and HCV-related HCC were selected, and the methylation levels of these genes were measured quantitatively using MALDI-TOF mass spectrometry. Expression levels of these 6 pairs of HCC and 4 more pairs of HCCs and surrounding noncancerous tissues were analyzed by expression array and are reported in this Series. <br><br>This experiment was reloaded in November 2010 after additional curation. this dataset is part of the TransQST collection.
2010-07-06 | E-GEOD-19665 | biostudies-arrayexpress
Project description:Non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) is increasing globally, but its molecular features are not well defined. We aimed to identify unique molecular traits characterizing NASH-HCC compared to other HCC aetiologies. We collected 80 NASH-HCC and 125 NASH samples from 5 institutions. Expression array (n=53 NASH-HCC; n=74 NASH) and whole exome sequencing (n=50 NASH-HCC) data were compared to HCCs of other aetiologies (n=184). Three NASH-HCC mouse models were analysed with RNAseq/expression-array (n=20). ACVR2A was silenced in HCC cells and proliferation assessed by MTT and colony formation assays. Mutational profiling of NASH-HCC tumours revealed TERT-promoter (56%), CTNNB1 (28%), TP53 (18%) and ACVR2A (10%) as the most-frequently mutated genes. ACVR2A mutation rates were higher in NASH-HCC than in other HCC aetiologies (10% versus 3%, p<0.05). In vitro, ACVR2A silencing prompted a significant increase in cell proliferation in HCC cells. We identified a novel mutational signature (MutSig-NASH-HCC) significantly associated with NASH-HCC (16% vs 2% in viral/alcohol-HCC, p=0.03). Tumour mutational burden (TMB) was higher in non-cirrhotic than in cirrhotic NASH-HCCs (1.45 versus 0.94 mutations/Mb; p<0.0017). Compared to other aetiologies of HCC, NASH-HCCs were enriched in bile and fatty acid signalling, oxidative stress and inflammation, and presented a higher fraction of Wnt/TGF-β proliferation subclass tumours (42% versus 26%, p=0.01) and a lower prevalence of the CTNNB1 subclass. Compared to other aetiologies, NASH-HCC showed a significantly higher prevalence of immunosuppressive cancer field. In three murine models of NASH-HCC key features of human NASH-HCC were preserved. NASH-HCCs display unique molecular features including higher rates of ACVR2A mutations and the presence of a newly identified mutational signature.
2021-06-29 | GSE164760 | GEO
Project description:Hepatocellular carcinoma (HCC) is a deadly disease, often unnoticed till the late stages, where treatment options become limited. Thus, there is a critical need to identify early biomarkers for detection of the developing HCC, as well as molecular pathways that would be amenable to therapeutic intervention. While efforts using human serum and tissues from late stage patients have been undertaken, progress has been limited. We have therefore explored the possibility of utilizing established mouse models for the discovery of biomarkers, as well as to understand in a systematic manner the molecular pathways that are progressively deregulated by the various etiological factors in contributing to HCC formation. As an initial effort, we have used the Hepatitis B surface antigen (HBsAg) transgenic mice as a hepatitis model, which have been exposed to aflatoxin B1 (AFB1). In this report, we present the initial findings from a extensive longitudinal study, which confirms the synergistic effect of both these etiological factors, with a gender bias towards male mice. Tumors from the mouse models were validated both histologically as well as by molecular transcriptome analysis by comparison with human HCCs. In addition, using these models, we have identified carnitine as a novel biomarker for HCC development, which was again validated using human HCC samples. Conclusion: This study therefore highlights the utility of these mouse models in identifying biomarkers for detection of human HCCs, as well as for the systematic analysis of molecular pathways that are affected by various etiological agents during the progression of HCC from an untransformed hepatocyte, which could provide novel options for targeted therapy.
2014-01-15 | GSE54054 | GEO
Project description:We profiled the mutations and gene expressions of early and advanced hepatocellular carcinoma (HCC) related with Hepatitis B-viral infection. Integrative analysis was performed with whole-exome sequencing and gene expression profiles of the 12 cases of early and advanced HCCs and paired non-tumoral adjacent liver tissues. 12 HCC Samples
2014-10-19 | E-GEOD-62441 | biostudies-arrayexpress
Project description:Chronic infections by hepatitis B virus (HBV) and hepatitis C virus (HCV) appear to be the most significant causes of hepatocellular carcinoma (HCC). Aberrant promoter methylation is known to be deeply involved in cancer, including HCC. In this study, we analyzed aberrant promoter methylation on genome-wide scale in 6 HCCs including 3 HBV-related and 3 HCV-related HCCs, 6 matched noncancerous liver tissues and 3 normal liver tissues by methylated DNA immunoprecipitation-on-chip analysis. Candidate genes with promoter methylation were detected more frequently in HCV-related HCC. Candidate genes methylated preferentially to HBV-related or HCV-related HCCs were detected and selected, and methylation levels of the selected genes were validated using 125 liver tissue samples, including 61 HCCs (28 HBV-related HCCs and 33 HCV-related HCCs) and matched 59 matched noncancerous livers, and 5 normal livers, by quantitative methylation analysis using MALDI-TOF mass spectrometry. Among analyzed genes, preferential methylation in HBV-related HCC was validated in 1 gene only. However, 15 genes were found methylated preferentially in HCV-related HCC, which was independent from age. Hierarchical clustering of HCC using these 15 genes stratified HCV-related HCC as a cluster of frequently methylated samples. The 15 genes included genes inhibitory to cancer-related signaling such as RAS/RAF/ERK and Wnt/b-catenin pathways. It was indicated that genes methylated preferentially in HCV-related HCC exist, and it was suggested that DNA methylation might play an important role in HCV-related HCC by silencing cancer-related pathway inhibitors.
2010-07-06 | GSE19665 | GEO
Project description:We profiled the mutations and gene expressions of early and advanced hepatocellular carcinoma (HCC) related with Hepatitis B-viral infection. Integrative analysis was performed with whole-exome sequencing and gene expression profiles of the 12 cases of early and advanced HCCs and paired non-tumoral adjacent liver tissues.
2014-10-19 | GSE62441 | GEO
Project description:<p>International differences in the incidence of many cancer types indicate the existence of carcinogen exposures that have not been identified by conventional epidemiology yet potentially make a substantial contribution to cancer burden1. This pertains to clear cell renal cell carcinoma (ccRCC), for which obesity, hypertension, and tobacco smoking are risk factors but do not explain its geographical variation in incidence2. Some carcinogens generate somatic mutations and a complementary strategy for detecting past exposures is to sequence the genomes of cancers from populations with different incidence rates and infer underlying causes from differences in patterns of somatic mutations. Here, we sequenced 962 ccRCC from 11 countries of varying incidence. Somatic mutation profiles differed between countries. In Romania, Serbia and Thailand, mutational signatures likely caused by extracts of Aristolochia plants were present in most cases and rare elsewhere. In Japan, a mutational signature of unknown cause was found in >70% cases and <2% elsewhere. A further mutational signature of unknown cause was ubiquitous but exhibited higher mutation loads in countries with higher kidney cancer incidence rates (p-value <6 × 10−18). Known signatures of tobacco smoking correlated with tobacco consumption, but no signature was associated with obesity or hypertension suggesting non-mutagenic mechanisms of action underlying these risk factors. The results indicate the existence of multiple, geographically variable, mutagenic exposures potentially affecting 10s of millions of people and illustrate the opportunities for new insights into cancer causation through large-scale global cancer genomics.</p><p><br></p><p><strong>Linked cross omic data sets:</strong></p><p>Geographic variation of mutagenic exposures in kidney cancer genomes – patient metadata files (<strong>Mutographs</strong>) associated with this study are available in the <strong>European Genome-Phenome Archive</strong>: https://ega-archive.org/datasets/EGAD00001012223.</p>
2024-03-26 | MTBLS9394 | MetaboLights
Project description:Gene-expression profiles of liver and hepatocellular carcinoma induced by diethylnitrosamine (DEN) in KLF6 +/- and wild type KLF6 mice. Inactivation of the KLF6 tumor suppressor is common in HCC due to hepatitis C virus (HCV), consistent with its anti-proliferative activity in HCC-derived cell lines and in hepatocytes of transgenic mice. We have evaluated the impact of KLF6 depletion on human HCC and experimental hepatocarcinogenesis. In patients with surgically resected HCC, those with significantly reduced tumor expression of KLF6 had a significantly decreased survival. We modeled this event in KLF6 +/- mice, which displayed significantly more tumorigenicity than KLF6 +/+ animals in response to the hepatic carcinogen DEN, associated with recapitulation of gene signatures in both surrounding tissue and tumors that are associated with aggressive human HCCs. In DNA microarrays, mdm2 mRNA expression was increased in tumors from KLF6 +/- compared to KLF6 +/+ mice, which was validated by realtime qPCR and Western blot in both human HCC and DEN-induced murine tumors. Moreover, chromosomal immunoprecipitation and co-transfection assays established the P2 intronic promoter of mdm2 as a bona fide transcriptional target repressed by KLF6. Whereas KLF6 over-expression in HCC cell lines led to reduced MDM2 levels and increased p53 protein and transcriptional activity, reduction in KLF6 by siRNA led to increased MDM2 and reduced p53. Our findings indicate that KLF6 deficiency contributes significantly to the carcinogenic milieu in human and murine HCC, and uncover a novel tumor suppressor activity of KLF6 in HCC, by linking its transcriptional repression of MDM2 to stabilization of p53. Keywords: Liver, Hepatocellular carcinoma, Expression array, Exon array, Affymetrix
2011-08-01 | GSE23375 | GEO
Project description:Gene-expression profiles of hepatitis C-related, early-stage liver cirrhosis Background & Aims: Liver cirrhosis affects 1%M-bM-^HM-^R2% of population and is the major risk factor of hepatocellular carcinoma (HCC). Hepatitis C cirrhosis-related HCC is the most rapidly increasing cause of cancer death in the US. Non-invasive methods have been developed to identify patients with asymptomatic, early-stage cirrhosis, increasing the burden of HCC surveillance, but biomarkers are needed to identify patients with cirrhosis who are most in need of surveillance. We investigated whether a liver-derived 186-gene signature previously associated with outcomes of patients with HCC is prognostic for patients newly diagnosed with cirrhosis but without HCC. Methods: We performed gene expression profile analysis of formalin-fixed needle biopsies from the livers of 216 patients with hepatitis C-related early-stage (Child-Pugh class A) cirrhosis who were prospectively followed for a median of 10 years at an Italian center. We evaluated whether the 186-gene signature was associated with death, progression of cirrhosis, and development of HCC. Results: Fifty-five (25%), 101 (47%), and 60 (28%) patients were classified as having poor-, intermediate-, and good-prognosis signatures, respectively. In multivariable Cox regression modeling, the poor-prognosis signature was significantly associated with death (P=.004), progression to advanced cirrhosis (P<.001), and development of HCC (P=.009). The 10-year rates of survival were 63%, 74%, and 85% and the annual incidences of HCC were 5.8%, 2.2%, and 1.5% for patients with poor-, intermediate-, and good-prognosis signatures, respectively. Conclusions: A 186-gene signature used to predict outcomes of patients with HCC is also associated with outcomes of patients with hepatitis C-related early-stage cirrhosis. This signature might be used to identify patients with cirrhosis in most need of surveillance and strategies to prevent their development of HCC. 216 liver biopsy specimens
2013-01-22 | E-GEOD-15654 | biostudies-arrayexpress