Sequencing to Identify Gene Variants in Familial Colorectal Cancer
Ontology highlight
ABSTRACT:
DISEASE(S): Colorectal Cancer,Colorectal Neoplasms
PROVIDER: 2148709 | ecrin-mdr-crc |
REPOSITORIES: ECRIN MDR
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Project description:The majority of the clinical situations suggestive of an increased genetic risk for colorectal cancer (CRC) are not explained by a simple monogenic model. Our working hypothesis is that a fraction of clinical conditions suggestive of an increased genetic risk for CRC (familial aggregation, early age of tumour onset, development of multiple primary CRC) is due to the combination of a limited number of genetic variations, each conferring a moderate risk for CRC, but whose combination results into high risk.
This study, which will be both retrospective and prospective, is an association study that will compare frequencies of selected genetic variations, alone or in combination, between patients (cases) whose clinical presentation is suggestive of an increased genetic risk but who do not present a known Mendelian form of CRC, and controls, in order to assess associations of these variations with non-Mendelian genetic forms of CRC. The inclusion criteria will be: CRC in two first degree relatives, one being diagnosed before 61 years of age; or CRC diagnosed before 51 years of age or advanced colorectal adenoma before 41 years of age; or multiple primary CRCs in the same individual, the first being diagnosed before 61 years of age The exclusion criteria will be: Lynch syndrome, adenomatous polyposis and hamartomatous polyposis. The genetic variations which will be analyzed will include (i) SNPs detected by GWAS and associated to CRC. (ii) Risk factors corresponding to functional polymorphisms within candidate genes. (iii) Imbalance of the TGFbR1 allelic expression. Sample sizes were calculated to obtain 80% power for an odds ratio of 2.5 since the aim of this study is to determine genetic variations conferring a moderate risk. In order to cover all these possibilities and to have reasonable even for the genetic variations with low frequency below 0.03 or high frequency above 0.90, the target sample size was set at 700 cases and 350 controls. The recruitment of patients will be performed at the national level by the cancer genetics departments ensuring a correct evaluation of the personal and familial history and the French molecular diagnosis laboratories network ensuring in routine the analysis of the main genes involved in CRC. The control population will be composed of healthy subjects of Caucasian origin between 45 and 60 years of age, without personal or familial history among their first-degree relatives of colorectal tumours.
Demonstration that the combination of a limited number of genetic variations, each conferring a moderate risk for CRC, results into high risk would allow to base, in selected families, the evaluation of risk in relatives and indication of colonoscopy on the analysis of gene variants the combination of which would confer a high risk. This study will confirm or invalidate the contribution of aTGFbR1 allelic expression imbalance in the determinism of early-onset CRC and familial aggregation of CRC. The demonstration of the involvement in CRC genetic variations with strong effect of specific combinations should be of interest for our general understanding of the molecular basis of CRC.
| 2084111 | ecrin-mdr-crc
Project description:Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with increased risk for colorectal cancer (CRC). A molecular understanding of the functional consequences of this genetic variation is complicated because most GWAS SNPs are located in non-coding regions. After identifying H3K27Ac peaks in HCT116 colon cancer cells that harbor SNPs associated with an increased risk for CRC, we used CRISPR/Cas9 nuclease to delete 2 CRC risk-associated H3K27Ac peaks (E7 and E24), a peak that is not associated with CRC risk (18qE) and a region that doesn?t have H3K27Ac peak (18qNE) from HCT116 cells and analyzed effects on the transcriptome and epigenome. We also deleted E7 region from HEK 293 cells and analyzed effects on the transcriptome of HEK 293. We also confirmed the physical interaction between enhancers of our interest and their putative target genes.
2016-01-12 | GSE72631 | GEO
Project description:Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with increased risk for colorectal cancer (CRC). A molecular understanding of the functional consequences of this genetic variation is complicated because most GWAS SNPs are located in non-coding regions. After identifying H3K27Ac peaks in HCT116 colon cancer cells that harbor SNPs associated with an increased risk for CRC, we used CRISPR/Cas9 nuclease to delete 2 CRC risk-associated H3K27Ac peaks (E7 and E24), a peak that is not associated with CRC risk (18qE) and a region that doesn?t have H3K27Ac peak (18qNE) from HCT116 cells and analyzed effects on the transcriptome and epigenome. We also deleted E7 region from HEK 293 cells and analyzed effects on the transcriptome of HEK 293. We also confirmed the physical interaction between enhancers of our interest and their putative target genes. Analysis of RNA-seq data and ChIP-seq between control clones and enhancer deleted clones in HCT116 cell. For Control, gRNA empty vectorplasmid was transfected with Cas9-GFP. For Deletion, gRNAs that have enhancer target sequences were transfected along with Cas9-GFP. Cells with high GFP expression were identified using fluorescence-activated cell sorting. Sorted cells were plated into individual wells of a 24 well plate and then re-plated as single cells in 10cm dishes and subsequently expanded for further analyses. Samples used in this study were clonal populations. Interaction profiling of enhancers of interest with putative target genes using 4C-seq
2016-01-12 | E-GEOD-72631 | biostudies-arrayexpress
Project description:Background: Causative genes for autosomal dominantly inherited familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC) have been well characterized. There is, however, another 10-15 % early onset colorectal cancer (CRC) whose genetic components are currently unknown. In this study, we used DNA chip technology to systematically search for genes differentially expressed in early onset CRC. Keywords: disease state analysis
2007-03-20 | GSE4107 | GEO
Project description:Colorectal cancer (CRC) incidence increases with age and early onset of the disease is an indication of genetic predisposition, estimated to cause up to 30 % of all CRC cases. To identify genes associated with an increased risk for CRC, genome-wide gene expression levels of CRCs from patients diagnosed at an early age and CRCs from patients diagnosed at higher age were investigated. Patients with known hereditary predisposition syndromes were excluded from the study.
2011-09-07 | GSE25071 | GEO
Project description:Site-specific variation in colorectal cancer (CRC) incidence, biology and prognosis are poorly understood. We sought to determine whether common genetic variants influencing CRC risk might exhibit topographical differences on CRC risk through regional differences in effects on gene expression in the large bowel mucosa. We conducted a site-specific genetic association study (10,630 cases, 31,331 controls) to identify whether established risk variants exert differential effects on risk of proximal, compared to distal CRC. We collected normal colorectal mucosa and blood from 481 subjects and assessed mucosal gene expression using Illumina HumanHT-12v4 arrays in relation to germline genotype. Expression quantitative trait loci (eQTLs) were explored by anatomical location of sampling. Normal colorectal mucosa was analyzed from both CRC patients and healthy controls.
2021-04-29 | GSE161023 | GEO
Project description:Colorectal cancer (CRC) is among the best examples depicting the relationship between inflammation and increased cancer risk. The introduction of new therapeutic options targeting the inflammatory mediators has been shown to markedly decrease the overall risk of CRC even though their chemopreventive potential is still under debate [1,2]. Specifically, conflicting reports exist concerning the relationship between Infliximab, a monoclonal antibody that specifically blocks Tumor Necrosis Factor (TNF), and an increased risk of CRC in patients with Inflammatory Bowel Disease (IBD). To address the axis between TNF and CRC development and progression, we depleted the Tnf from our previously established murine model of colitis-associated cancer (CAC), the Winnie-ApcMin/+ line. Surprisingly, a detailed histological characterization, demonstrated that the deletion of Tnf in Winnie-ApcMin/+ mice resulted in an initial reduction of dysplastic lesions incidence in 5-week-old mice, followed by faster disease progression with a unique molecular pattern at 8 weeks. Our results highlight that TNF could exert a dual role in CAC supporting the promotion of neoplastic lesions onset at the early stage of the disease and inducing their reduction during disease progression.
2023-05-01 | E-MTAB-12356 | biostudies-arrayexpress
Project description:Genetic mutations on leucine-rich repeat kinase 2 (LRRK2) have been associated with an increased risk of Parkinson's disease. The Gly2019Ser (G2019S) mutation on LRRK2 gene is a relatively common cause of familial Parkinson's disease in Caucasian population. In this study, we generated H9 hESC harboring LRRK2 (G2019S) mutation by gene knockin. Wildtype and LRRK2 mutant hESC were differentiated into NSC using a chemically defined protocol.
2012-10-17 | GSE36321 | GEO
Project description:Background: Familial melanoma accounts for 10% of cases, withCDKN2A being the main high-risk gene. However, the mechanisms underlying melanomagenesis in individuals at high risk of developing melanoma remain poorly understood. Objective: To analyze the transcriptome of melanocyte/keratinocyte co-cultures derived from healthy skin from familial melanoma patients vs. controls, to comprehend melanoma development. Methods: Primary melanocyte-keratinocyte co-cultures were established from healthy skin biopsies from 16 unrelated familial melanoma patients (8 CDKN2A mutant, 8 CDKN2A wild-type) and from 7 healthy controls. Whole transcriptome was captured using the SurePrint G3 Human Microarray. Transcriptome analyses included: differential gene expression, functional enrichment, and protein-protein interaction (PPI) networks. Results: We identified a gene profile associated with familial melanoma independently of CDKN2A germline status. Functional enrichment analysis of this profile showed a downregulation of pathways related to DNA repair and immune response in familial melanoma (P < 0.05). In addition, the PPI network analysis revealed a network that consisted of double stranded DNA repair genes (including BRCA1, BRCA2, BRIP1, and FANCA), immune response genes and regulation of chromosome segregation. The hub gene was BRCA1. Conclusion: The constitutive deregulation of BRCA1 pathway genes and immune response in healthy skin could be a mechanism related with melanoma risk.
2022-11-02 | GSE160902 | GEO
Project description:Esophageal cancer is among the 10 most common malignancies and ranks as the 6th leading cause of death from cancer. It constitutes 7% of all gastrointestinal cancers and is one of the most lethal of all cancers. The large variation in the incidence of esophageal cancer in different geographic regions has often been thought to be due to variation in exposure to environmental factors; however, hereditary factors may also contribute to the variation in rates. A positive family history was found to be associated with an increased risk of esophageal cancer in several case-control and cohort studies in China. Familial aggregation also has been observed in Iran and Japan. The cancer data generated from six hospital based cancer registries in India under National Cancer Registry Programme (NCRP, Annual Report, 2003-2004) has revealed that the occurrence of esophageal cancer in Assam is highest in India. The aggregation of esophageal cancer in families is a long-observed and well-documented phenomenon in Assam of North-east part of India (AAR=32.6). In Assam high incidence of esophageal cancer with familial aggregation need investigation for etiology. The etiology of esophageal cancer in Northeast Indian population is different from other population at India due to wide variations in dietary habits or nutritional factors, tobacco chewing and alcohol habits. With in these high-risk regions, studies have shown a strong tendency toward familial aggregation, suggesting that genetic susceptibility, in conjunction with potential environmental exposures, may be involved in the etiology of esophageal cancer. Familial clustering of cancer has been one of the main avenues to the understanding of cancer etiology and the signal to the involvement of heritable genes. Familial clustering of cancer may be due to environmental factors shared by family members or due to shared genes. However, the familial aggregation of esophageal cancer among the population in northeast India may reflect the influence of environmental factors operating on individuals who are already genetically susceptible. Epidemiological studies indicate that tobacco smoking and alcohol consumption are the major factors for esophageal cancer, the role of genetic factors for familial aggregation has not been elucidated. In this study, tumor and matched normal tissue from esophageal squamous cell carcinoma patients with a family history of upper gastrointestinal cancer were analyzed using cDNA microarray containing 10,000genes to evaluate gene expression differences in esophageal squamous cell carcinoma patients with a family history of upper gastrointestinal cancer from a high- risk area in India. To identify alteration in genes and molecular functional pathways in esophageal cancer in a high incidence region of India where there is wide spread use of tobacco and betel quid with fermented areca nuts and familial aggregation cancer. Keywords: Gene Expression
2008-02-09 | GSE10127 | GEO