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1.
Int J Cancer ; 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209889

RESUMO

Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p-value = 3.5 × 10-6 ) and rs2189517 (in RAD51B) with rectal cancer risk (p-value = 5.7 × 10-6 ). The results had statistical significance close to the Bonferroni corrected p-value of 5.8 × 10-6 . Ninety-four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis-eQTL suggesting possible mechanisms of carcinogenesis.

3.
Int J Epidemiol ; 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31038671

RESUMO

BACKGROUND: Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown. METHODS: Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis. RESULTS: During 18-20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (Pheterogeneity=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584). CONCLUSIONS: Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC.

4.
Hepatol Commun ; 2(7): 786-797, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30202815

RESUMO

Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).

5.
Genome Biol ; 19(1): 142, 2018 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-30253799

RESUMO

BACKGROUND: Previous approaches to defining subtypes of colorectal carcinoma (CRC) and other cancers based on transcriptomes have assumed the existence of discrete subtypes. We analyze gene expression patterns of colorectal tumors from a large number of patients to test this assumption and propose an approach to identify potentially a continuum of subtypes that are present across independent studies and cohorts. RESULTS: We examine the assumption of discrete CRC subtypes by integrating 18 published gene expression datasets and > 3700 patients, and contrary to previous reports, find no evidence to support the existence of discrete transcriptional subtypes. Using a meta-analysis approach to identify co-expression patterns present in multiple datasets, we identify and define robust, continuously varying subtype scores to represent CRC transcriptomes. The subtype scores are consistent with established subtypes (including microsatellite instability and previously proposed discrete transcriptome subtypes), but better represent overall transcriptional activity than do discrete subtypes. The scores are also better predictors of tumor location, stage, grade, and times of disease-free survival than discrete subtypes. Gene set enrichment analysis reveals that the subtype scores characterize T-cell function, inflammation response, and cyclin-dependent kinase regulation of DNA replication. CONCLUSIONS: We find no evidence to support discrete subtypes of the CRC transcriptome and instead propose two validated scores to better characterize a continuity of CRC transcriptomes.

6.
Am J Hum Genet ; 102(5): 904-919, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29727690

RESUMO

Genome-wide association studies (GWASs) have successfully identified thousands of genetic variants for many complex diseases; however, these variants explain only a small fraction of the heritability. Recently, genetic association studies that leverage external transcriptome data have received much attention and shown promise for discovering novel variants. One such approach, PrediXcan, is to use predicted gene expression through genetic regulation. However, there are limitations in this approach. The predicted gene expression may be biased, resulting from regularized regression applied to moderately sample-sized reference studies. Further, some variants can individually influence disease risk through alternative functional mechanisms besides expression. Thus, testing only the association of predicted gene expression as proposed in PrediXcan will potentially lose power. To tackle these challenges, we consider a unified mixed effects model that formulates the association of intermediate phenotypes such as imputed gene expression through fixed effects, while allowing residual effects of individual variants to be random. We consider a set-based score testing framework, MiST (mixed effects score test), and propose two data-driven combination approaches to jointly test for the fixed and random effects. We establish the asymptotic distributions, which enable rapid calculation of p values for genome-wide analyses, and provide p values for fixed and random effects separately to enhance interpretability over GWASs. Extensive simulations demonstrate that our approaches are more powerful than existing ones. We apply our approach to a large-scale GWAS of colorectal cancer and identify two genes, POU5F1B and ATF1, which would have otherwise been missed by PrediXcan, after adjusting for all known loci.

7.
Dig Dis Sci ; 63(3): 738-745, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29372477

RESUMO

BACKGROUND: While monoclonal antibodies against tumor necrosis factor-α (TNFα) are effective in treating Crohn's disease (CD), approximately one-third of patients lose response. The mechanisms underlying this loss of response remain elusive. AIM: We sought to determine if novel biological pathways, including TNFα-independent inflammatory pathways, emerge in those with loss of response to anti-TNFα. METHODS: Using RNA microarray technology in 28 patients with CD, we examined the colonic gene expression differences between those with active inflammation in the setting of loss of response to TNFα-antagonist therapy ("loss of responders") compared to anti-TNFα naïve patients with active inflammation and those on anti-TNF therapy in disease remission. Pathway enrichment analyses were performed. RESULTS: We found that colonic expression of chemokines known to drive inflammation (CXCL20, CXCL9, and CXCL10) was elevated in those with loss of response compared to those in remission. Expression of genes critical to modulating oxidative stress burden (DUOX2, DUOXA2, and NOS2) was also elevated. Additionally, MMP3, MMP1, and MMP12 were elevated in those with continued inflammation. Gene enrichment analysis revealed that loss of responders exhibited dysregulation in the cysteine and methionine metabolism pathway, suggesting alteration in oxidative stress burden. There were no differences in genes or pathways between loss of responders and those who were TNFα-naïve. However, loss of response occurred despite the ability of anti-TNFα therapy to normalize APO gene expression. CONCLUSION: Our analyses suggest that loss of response to anti-TNFα is not driven by the emergence of pathways that bypass the action or induce resistance to anti-TNFα therapy.


Assuntos
Anti-Inflamatórios/uso terapêutico , Doença de Crohn/tratamento farmacológico , Tolerância a Medicamentos/fisiologia , Fármacos Gastrointestinais/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/uso terapêutico , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Feminino , Humanos , Infliximab/uso terapêutico , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Indução de Remissão , Adulto Jovem
8.
Clin Transl Gastroenterol ; 8(2): e73, 2017 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-28181993

RESUMO

OBJECTIVES: Obesity is an important risk factor for the development of colorectal cancer (CRC). Although the impact of bariatric surgery on CRC is conflicting, its impact on precursor lesions is unknown. The aim of this study was to determine whether bariatric surgery before index screening colonoscopy is associated with decreased development of colorectal adenomas. METHODS: We performed a retrospective cohort study of bariatric surgery patients who had undergone index, screening colonoscopy at an academic center from 2001 to 2014. Patients who had bariatric surgery at least 1 year before index colonoscopy were compared with those who had surgery after colonoscopy, using multivariable logistic regression to control for presurgical body mass index, sex, gender, race, type of surgery, aspirin use, metformin use, smoking, and age at colonoscopy. RESULTS: One hundred and twenty-five obese individuals who had bariatric surgery before colonoscopy were compared with 223 individuals who had colonoscopy after surgery. Adenomatous polyps were found in 16.8% of individuals who had surgery first vs. 35.5% who had colonoscopy before bariatric surgery (unadjusted odds ratio (OR) 0.37, 95% confidence interval (CI): 0.21-0.64, P=0.0003). After multivariable adjustment, bariatric surgery before index screening colonoscopy was associated with a decreased risk of adenomas at index colonoscopy (adjusted OR 0.37, 95% CI: 0.19-0.69, P=0.002). CONCLUSIONS: Bariatric surgery is associated with a decreased risk of colorectal adenomas in obese individuals without a family history of CRC.

9.
Trials ; 18(1): 50, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28143522

RESUMO

BACKGROUND: Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties. METHODS/DESIGN: ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function. DISCUSSION: Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers. TRIAL REGISTRATION: This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769 . Registered on 16 March 2015.


Assuntos
Adenoma/tratamento farmacológico , Anticarcinógenos/administração & dosagem , Aspirina/administração & dosagem , Carcinoma/prevenção & controle , Neoplasias Colorretais/tratamento farmacológico , Adenoma/metabolismo , Adenoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticarcinógenos/efeitos adversos , Aspirina/efeitos adversos , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/urina , Boston , Carcinoma/metabolismo , Carcinoma/patologia , Protocolos Clínicos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Citocinas/sangue , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Prostaglandinas/urina , Fatores de Proteção , Projetos de Pesquisa , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
10.
PLoS One ; 11(7): e0157521, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27379672

RESUMO

Genome-wide association studies (GWAS) have identified many common single nucleotide polymorphisms (SNPs) associated with colorectal cancer risk. These SNPs may tag correlated variants with biological importance. Fine-mapping around GWAS loci can facilitate detection of functional candidates and additional independent risk variants. We analyzed 11,900 cases and 14,311 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. To fine-map genomic regions containing all known common risk variants, we imputed high-density genetic data from the 1000 Genomes Project. We tested single-variant associations with colorectal tumor risk for all variants spanning genomic regions 250-kb upstream or downstream of 31 GWAS-identified SNPs (index SNPs). We queried the University of California, Santa Cruz Genome Browser to examine evidence for biological function. Index SNPs did not show the strongest association signals with colorectal tumor risk in their respective genomic regions. Bioinformatics analysis of SNPs showing smaller P-values in each region revealed 21 functional candidates in 12 loci (5q31.1, 8q24, 11q13.4, 11q23, 12p13.32, 12q24.21, 14q22.2, 15q13, 18q21, 19q13.1, 20p12.3, and 20q13.33). We did not observe evidence of additional independent association signals in GWAS-identified regions. Our results support the utility of integrating data from comprehensive fine-mapping with expanding publicly available genomic databases to help clarify GWAS associations and identify functional candidates that warrant more onerous laboratory follow-up. Such efforts may aid the eventual discovery of disease-causing variant(s).


Assuntos
Neoplasias Colorretais/genética , Predisposição Genética para Doença/genética , Variação Genética , Estudo de Associação Genômica Ampla/métodos , Células A549 , Adulto , Idoso , Idoso de 80 Anos ou mais , Células CACO-2 , Mapeamento Cromossômico , Neoplasias Colorretais/patologia , Biologia Computacional/métodos , Feminino , Genótipo , Células HCT116 , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Sistema de Registros/estatística & dados numéricos , Fatores de Risco , Adulto Jovem
11.
J Mol Diagn ; 18(5): 697-706, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27471182

RESUMO

Next-generation sequencing has evolved technically and economically into the method of choice for interrogating the genome in cancer and inherited disorders. The introduction of procedural code sets for whole-exome and genome sequencing is a milestone toward financially sustainable clinical implementation; however, achieving reimbursement is currently a major challenge. As part of a prospective quality-improvement initiative to implement the new code sets, we adopted Agile, a development methodology originally devised in software development. We implemented eight functionally distinct modules (request review, cost estimation, preauthorization, accessioning, prebilling, testing, reporting, and reimbursement consultation) and obtained feedback via an anonymous survey. We managed 50 clinical requests (January to June 2015). The fraction of pursued-to-requested cases (n = 15/50; utilization management fraction, 0.3) aimed for a high rate of preauthorizations. In 13 of 15 patients the insurance plan required preauthorization, which we obtained in 70% and ultimately achieved reimbursement in 50%. Interoperability enabled assessment of 12 different combinations of modules that underline the importance of an adaptive workflow and policy tailoring to achieve higher yields of reimbursement. The survey confirmed a positive attitude toward self-organizing teams. We acknowledge the individuals and their interactions and termed the infrastructure: human pipeline. Nontechnical barriers currently are limiting the scope and availability of clinical genomic sequencing. The presented human pipeline is one approach toward long-term financial sustainability of clinical genomics.


Assuntos
Assistência à Saúde , Genômica , Informática Médica/métodos , Software , Assistência à Saúde/economia , Assistência à Saúde/métodos , Assistência à Saúde/organização & administração , Exoma , Genômica/economia , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Informática Médica/economia , Encaminhamento e Consulta , Mecanismo de Reembolso , Pesquisa , Inquéritos e Questionários , Fluxo de Trabalho , Recursos Humanos
12.
Int J Cancer ; 139(12): 2655-2670, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27459707

RESUMO

Telomeres cap chromosome ends, protecting them from degradation, double-strand breaks, and end-to-end fusions. Telomeres are maintained by telomerase, a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. Loci in the TERT and adjoining CLPTM1L region are associated with risk of multiple cancers. We therefore investigated associations between variants in 22 telomere structure and maintenance gene regions and colorectal, breast, prostate, ovarian, and lung cancer risk. We performed subset-based meta-analyses of 204,993 directly-measured and imputed SNPs among 61,851 cancer cases and 74,457 controls of European descent. Independent associations for SNP minor alleles were identified using sequential conditional analysis (with gene-level p value cutoffs ≤3.08 × 10-5 ). Of the thirteen independent SNPs observed to be associated with cancer risk, novel findings were observed for seven loci. Across the DCLRE1B region, rs974494 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Across the TERC region, rs75316749 was positively associated with colorectal, breast, ovarian, and lung cancers. Across the DCLRE1B region, rs974404 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Near POT1, rs116895242 was inversely associated with colorectal, ovarian, and lung cancers, and RTEL1 rs34978822 was inversely associated with prostate and lung cancers. The complex association patterns in telomere-related genes across cancer types may provide insight into mechanisms through which telomere dysfunction in different tissues influences cancer risk.


Assuntos
Variação Genética , Neoplasias/epidemiologia , Neoplasias/genética , Homeostase do Telômero/genética , Telômero/genética , Alelos , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu , Estudos de Associação Genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Desequilíbrio de Ligação , Razão de Chances , Polimorfismo de Nucleotídeo Único , Risco , Telomerase/genética
13.
Gastroenterology ; 151(2): 351-363.e28, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27094239

RESUMO

BACKGROUND & AIMS: A genome-wide association study (GWAS) of 280 cases identified the hepatic cholesterol transporter ABCG8 as a locus associated with risk for gallstone disease, but findings have not been reported from any other GWAS of this phenotype. We performed a large-scale, meta-analysis of GWASs of individuals of European ancestry with available prior genotype data, to identify additional genetic risk factors for gallstone disease. METHODS: We obtained per-allele odds ratio (OR) and standard error estimates using age- and sex-adjusted logistic regression models within each of the 10 discovery studies (8720 cases and 55,152 controls). We performed an inverse variance weighted, fixed-effects meta-analysis of study-specific estimates to identify single-nucleotide polymorphisms that were associated independently with gallstone disease. Associations were replicated in 6489 cases and 62,797 controls. RESULTS: We observed independent associations for 2 single-nucleotide polymorphisms at the ABCG8 locus: rs11887534 (OR, 1.69; 95% confidence interval [CI], 1.54-1.86; P = 2.44 × 10(-60)) and rs4245791 (OR, 1.27; P = 1.90 × 10(-34)). We also identified and/or replicated associations for rs9843304 in TM4SF4 (OR, 1.12; 95% CI, 1.08-1.16; P = 6.09 × 10(-11)), rs2547231 in SULT2A1 (encodes a sulfoconjugation enzyme that acts on hydroxysteroids and cholesterol-derived sterol bile acids) (OR, 1.17; 95% CI, 1.12-1.21; P = 2.24 × 10(-10)), rs1260326 in glucokinase regulatory protein (OR, 1.12; 95% CI, 1.07-1.17; P = 2.55 × 10(-10)), and rs6471717 near CYP7A1 (encodes an enzyme that catalyzes conversion of cholesterol to primary bile acids) (OR, 1.11; 95% CI, 1.08-1.15; P = 8.84 × 10(-9)). Among individuals of African American and Hispanic American ancestry, rs11887534 and rs4245791 were associated positively with gallstone disease risk, whereas the association for the rs1260326 variant was inverse. CONCLUSIONS: In this large-scale GWAS of gallstone disease, we identified 4 loci in genes that have putative functions in cholesterol metabolism and transport, and sulfonylation of bile acids or hydroxysteroids.


Assuntos
Membro 8 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Cálculos Biliares/genética , Loci Gênicos/genética , Predisposição Genética para Doença , Adulto , Afro-Americanos/genética , Idoso , Estudos de Casos e Controles , Colesterol/metabolismo , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Estudo de Associação Genômica Ampla , Hispano-Americanos/genética , Humanos , Metabolismo dos Lipídeos/genética , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Polimorfismo de Nucleotídeo Único
14.
Carcinogenesis ; 37(1): 87-95, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26586795

RESUMO

Genome-wide association studies have identified several germline single nucleotide polymorphisms (SNPs) significantly associated with colorectal cancer (CRC) incidence. Common germline genetic variation may also be related to CRC survival. We used a discovery-based approach to identify SNPs related to survival outcomes after CRC diagnosis. Genome-wide genotyping arrays were conducted for 3494 individuals with invasive CRC enrolled in six prospective cohort studies (median study-specific follow-up = 4.2-8.1 years). In pooled analyses, we used Cox regression to assess SNP-specific associations with CRC-specific and overall survival, with additional analyses stratified by stage at diagnosis. Top findings were followed-up in independent studies. A P value threshold of P < 5×10(-8) in analyses combining discovery and follow-up studies was required for genome-wide significance. Among individuals with distant-metastatic CRC, several SNPs at 6p12.1, nearest the ELOVL5 gene, were statistically significantly associated with poorer survival, with the strongest associations noted for rs209489 [hazard ratio (HR) = 1.8, P = 7.6×10(-10) and HR = 1.8, P = 3.7×10(-9) for CRC-specific and overall survival, respectively). No SNPs were statistically significantly associated with survival among all cases combined or in cases without distant-metastases. SNPs in 6p12.1/ELOVL5 were associated with survival outcomes in individuals with distant-metastatic CRC, and merit further follow-up for functional significance. Findings from this genome-wide association study highlight the potential importance of genetic variation in CRC prognosis and provide clues to genomic regions of potential interest.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Neoplasias Colorretais/diagnóstico , Feminino , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos
16.
Nat Commun ; 6: 7138, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26151821

RESUMO

Genetic susceptibility to colorectal cancer is caused by rare pathogenic mutations and common genetic variants that contribute to familial risk. Here we report the results of a two-stage association study with 18,299 cases of colorectal cancer and 19,656 controls, with follow-up of the most statistically significant genetic loci in 4,725 cases and 9,969 controls from two Asian consortia. We describe six new susceptibility loci reaching a genome-wide threshold of P<5.0E-08. These findings provide additional insight into the underlying biological mechanisms of colorectal cancer and demonstrate the scientific value of large consortia-based genetic epidemiology studies.


Assuntos
Neoplasias Colorretais/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Estudos de Casos e Controles , Humanos , Razão de Chances , Polimorfismo de Nucleotídeo Único
17.
Carcinogenesis ; 36(9): 999-1007, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26071399

RESUMO

Although genome-wide association studies (GWAS) have separately identified many genetic susceptibility loci for ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC), there has been no large-scale examination for pleiotropy, or shared genetic susceptibility, for these conditions. We used logistic regression modeling to examine the associations of 181 UC and CD susceptibility variants previously identified by GWAS with risk of CRC using data from the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. We also examined associations of significant variants with clinical and molecular characteristics in a subset of the studies. Among 11794 CRC cases and 14190 controls, rs11676348, the susceptibility single nucleotide polymorphism (SNP) for UC, was significantly associated with reduced risk of CRC (P = 7E-05). The multivariate-adjusted odds ratio of CRC with each copy of the T allele was 0.93 (95% CI 0.89-0.96). The association of the SNP with risk of CRC differed according to mucinous histological features (P heterogeneity = 0.008). In addition, the (T) allele was associated with lower risk of tumors with Crohn's-like reaction but not tumors without such immune infiltrate (P heterogeneity = 0.02) and microsatellite instability-high (MSI-high) but not microsatellite stable or MSI-low tumors (P heterogeneity = 0.03). The minor allele (T) in SNP rs11676348, located downstream from CXCR2 that has been implicated in CRC progression, is associated with a lower risk of CRC, particularly tumors with a mucinous component, Crohn's-like reaction and MSI-high. Our findings offer the promise of risk stratification of inflammatory bowel disease patients for complications such as CRC.


Assuntos
Colite Ulcerativa/genética , Neoplasias Colorretais/genética , Doença de Crohn/genética , Instabilidade de Microssatélites , Colite Ulcerativa/complicações , Colite Ulcerativa/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/etiologia , Doença de Crohn/complicações , Doença de Crohn/epidemiologia , Grupo com Ancestrais do Continente Europeu , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único , Risco
18.
19.
Cancer Prev Res (Phila) ; 8(7): 614-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25899003

RESUMO

Oncogene-induced senescence (OIS), a tumor-suppressive mechanism that is induced by the replicative and metabolic stress of oncogene activation, is a key barrier in the development of BRAF V600E colon cancer. Inhibition of this mechanism has been observed through epigenetic changes observed in sporadic serrated polyps, as well as through the germline mutations associated with those who develop serrated polyposis. We hypothesize that upregulated autocrine factors exist that are specific to the serrated pathway and also promote bypass of oncogene-induced senescence. To identify such autocrine factors, we integrate analyses of microarrays of sessile serrated polyps and two large colon cancer cohorts, the Cancer Genome Atlas (TCGA; n = 153), and French national Cartes d'Identité des Tumeurs (CIT) program (n = 462), with enhanced gene annotation through natural language processing techniques of the existing medical corpus. We reproducibly associate higher expression of the ligand-receptor axis of TFF2 and CXCR4 with BRAF V600E-mutant colon cancer (P = 3.0 × 10(-3) and 0.077, respectively for TCGA; P = 3.0 × 10(-8) and 5.1 × 10(-7) for CIT). Given well-described oncogenic roles of TFF2 and CXCR4 in colon cancer, and availability of CXCR4 inhibitors for other clinical indications, this ligand-receptor axis may represent an actionable target for prevention and treatment of this molecular subtype of colorectal cancer.


Assuntos
Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Peptídeos/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Receptores CXCR4/metabolismo , Adenoma , Algoritmos , Bases de Dados Genéticas , Progressão da Doença , Humanos , Processamento de Linguagem Natural , Transdução de Sinais/fisiologia , Fator Trefoil-2
20.
Clin Cancer Res ; 21(7): 1543-8, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25501125

RESUMO

The anti-inflammatory properties of aspirin have resulted in its widespread use as an analgesic, antipyretic, and cardioprotective agent. Beyond these applications, multiple observational studies and randomized controlled trials have demonstrated a chemopreventative role for aspirin, particularly in the development of colorectal neoplasia. Given the critical importance of Wnt dysregulation in colorectal carcinogenesis, the interplay between aspirin and canonical Wnt signaling has become a focus of investigation. These studies have illuminated our understanding of the anticancer mechanisms of aspirin, yielding the identification of potential biomarkers for which aspirin's chemopreventative efficacy can be safely optimized into routine clinical practice and providing leads into the discovery of novel preventive and therapeutic targets. In this review, we summarize key experimental and clinical studies of this interaction, as well as highlighting future strategies to advance their clinical translation.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Neoplasias Colorretais/prevenção & controle , Terapia de Alvo Molecular/métodos , Neoplasias/prevenção & controle , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Humanos
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