[Show abstract][Hide abstract] ABSTRACT: Background: Red meat intake has been associated with risk of colorectal cancer (CRC), potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype, and CRC has been inconsistently reported. Methods: We used pooled individual-level data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Red meat intake was collected by each study. We inferred NAT2 phenotype based on polymorphism at rs1495741, highly predictive of enzyme activity. Interaction was assessed using multiplicative interaction terms in multivariate-adjusted models. Results: From 11 studies, 8,290 CRC cases and 9,115 controls were included. The highest quartile of red meat intake was associated with increased risk of CRC compared to the lowest quartile (OR 1.41, 95%CI 1.29 - 1.55). However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis. Combining all studies, high red meat intake was similarly associated with CRC in those with a rapid/intermediate NAT2 genotype (OR 1.38, 95%CI 1.20 - 1.59) as with a slow genotype (OR 1.43, 95%CI 1.28 - 1.61) (p- interaction=0.9). Conclusions: We found that high red meat intake was associated with increased risk of CRC only from retrospective case-control studies and not modified by NAT2 enzyme activity. Impact: Our results suggest no interaction between NAT2 genotype and red-meat intake in mediating risk of CRC.
[Show abstract][Hide abstract] ABSTRACT: Genome-wide association studies (GWAS) have identified 76 variants associated with prostate cancer risk predominantly in populations of European ancestry. To identify additional susceptibility loci for this common cancer, we conducted a meta-analysis of >10 million SNPs in 43,303 prostate cancer cases and 43,737 controls from studies in populations of European, African, Japanese and Latino ancestry. Twenty-three new susceptibility loci were identified at association P < 5 × 10(-8); 15 variants were identified among men of European ancestry, 7 were identified in multi-ancestry analyses and 1 was associated with early-onset prostate cancer. These 23 variants, in combination with known prostate cancer risk variants, explain 33% of the familial risk for this disease in European-ancestry populations. These findings provide new regions for investigation into the pathogenesis of prostate cancer and demonstrate the usefulness of combining ancestrally diverse populations to discover risk loci for disease.
[Show abstract][Hide abstract] ABSTRACT: Background: Calcium intake may reduce risk of colorectal cancer (CRC), but the mechanisms remain unclear. Studies of interaction between calcium intake and single nucleotide polymorphisms (SNPs) in calcium-related pathways have yielded inconsistent results. Methods: To identify gene-calcium interactions, we tested interactions between ~2.7 million SNPs across the genome with self-reported calcium intake (from dietary or supplemental sources) in 9,006 CRC cases and 9,503 controls of European ancestry. To test for multiplicative interactions, we used multivariable logistic regression and defined statistical significance using the conventional genome-wide α=5E-08. Results: After accounting for multiple comparisons, there were no statistically significant SNP-interactions with total, dietary, or supplemental calcium intake. Conclusions: We found no evidence of SNP-interactions with calcium intake for CRC risk in a large population of 18,509 individuals. Impact: These results suggest that in genome-wide analysis common genetic variants do not strongly modify the association between calcium intake and CRC in European populations.
Cancer Epidemiology Biomarkers & Prevention 09/2014; · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Only a fraction of colorectal cancer heritability is explained by known risk-conferring genetic variation. This study was designed to identify novel risk alleles in Europeans. We conducted a genome-wide association study (GWAS) meta-analysis of colorectal cancer in participants from a population-based case control study in Israel (n = 1,616 cases, 1,329 controls) and a consortium study from the Colon Cancer Family Registry (n=1,977 cases, 999 controls). We used a two-stage (discovery-replication) GWAS design, followed by a joint meta-analysis. A combined analysis identified a novel susceptibility locus that reached genome-wide significance on chromosome 4q32.2 (rs35509282, risk allele = T (minor allele frequency = 0.09); odds ratio per risk allele = 1.53; p-value = 8.2x10(-9); nearest gene = FSTL5). The direction of the association was consistent across studies. In addition, we confirmed that 14 of 29 previously identified susceptibility variants were significantly associated with risk of colorectal cancer in this study. Genetic variation on chromosome 4q32.2 is significantly associated with risk of colorectal cancer in Ashkenazi Jews and Europeans in this study.
[Show abstract][Hide abstract] ABSTRACT: Background: Genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) that are associated with risk of colorectal cancer (CRC). Prior research has evaluated the presence of gene-environment interaction involving the first 10 identified susceptibility loci, but little work has been conducted on interaction involving SNPs at recently identified susceptibility loci, including: rs10911251, rs6691170, rs6687758, rs11903757, rs10936599, rs647161, rs1321311, rs719725, rs1665650, rs3824999, rs7136702, rs11169552, rs59336, rs3217810, rs4925386, and rs2423279. Methods: Data on 9160 cases and 9280 controls from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colon Cancer Family Registry (CCFR) were used to evaluate the presence of interaction involving the above-listed SNPs and sex, body mass index (BMI), alcohol consumption, smoking, aspirin use, post-menopausal hormone (PMH) use, as well as intake of dietary calcium, dietary fiber, dietary folate, red meat, processed meat, fruit, and vegetables. Interaction was evaluated using a fixed-effects meta-analysis of an efficient Empirical Bayes estimator, and permutation was used to account for multiple comparisons. Results: None of the permutation-adjusted p-values reached statistical significance. Conclusions: The associations between recently identified genetic susceptibility loci and CRC are not strongly modified by sex, BMI, alcohol, smoking, aspirin, PMH use, and various dietary factors. Impact: Results suggest little evidence of gene-environment interaction involving recently identified susceptibility loci for CRC.
[Show abstract][Hide abstract] ABSTRACT: Known genetic loci explain only a small proportion of the familial relative risk of colorectal cancer (CRC). We conducted a genome-wide association study of CRC in East Asians with 14,963 cases and 31,945 controls and identified 6 new loci associated with CRC risk (P = 3.42 [times] 10-8 to 9.22 [times] 10-21) at 10q22.3, 10q25.2, 11q12.2, 12p13.31, 17p13.3 and 19q13.2. Two of these loci map to genes (TCF7L2 and TGFB1) with established roles in colorectal tumorigenesis. Four other loci are located in or near genes involved in transcriptional regulation (ZMIZ1), genome maintenance (FEN1), fatty acid metabolism (FADS1 and FADS2), cancer cell motility and metastasis (CD9), and cell growth and differentiation (NXN). We also found suggestive evidence for three additional loci associated with CRC risk near genome-wide significance at 8q24.11, 10q21.1 and 10q24.2. Furthermore, we replicated 22 previously reported CRC-associated loci. Our study provides insights into the genetic basis of CRC and suggests the in
[Show abstract][Hide abstract] ABSTRACT: The presence of multiple (5-100) colorectal adenomas suggests an inherited predisposition, but the genetic aetiology of this phenotype is undetermined if patients test negative for Mendelian polyposis syndromes such as familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). We investigated whether 18 common colorectal cancer (CRC) predisposition single-nucleotide polymorphisms (SNPs) could help to explain some cases with multiple adenomas who phenocopied FAP or MAP, but had no pathogenic APC or MUTYH variant. No multiple adenoma case had an outlying number of CRC SNP risk alleles, but multiple adenoma patients did have a significantly higher number of risk alleles than population controls (P=5.7 × 10(-7)). The association was stronger in those with ≥10 adenomas. The CRC SNPs accounted for 4.3% of the variation in multiple adenoma risk, with three SNPs (rs6983267, rs10795668, rs3802842) explaining 3.0% of the variation. In FAP patients, the CRC risk score did not differ significantly from the controls, as we expected given the overwhelming effect of pathogenic germline APC variants on the phenotype of these cases. More unexpectedly, we found no evidence that the CRC SNPs act as modifier genes for the number of colorectal adenomas in FAP patients. In conclusion, common colorectal tumour risk alleles contribute to the development of multiple adenomas in patients without pathogenic germline APC or MUTYH variants. This phenotype may have 'polygenic' or monogenic origins. The risk of CRC in relatives of multiple adenoma cases is probably much lower for cases with polygenic disease, and this should be taken into account when counselling such patients.European Journal of Human Genetics advance online publication, 7 May 2014; doi:10.1038/ejhg.2014.74.
European journal of human genetics: EJHG 05/2014; · 3.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rare copy-number variation (CNV) is an important source of risk for autism spectrum disorders (ASDs). We analyzed 2,446 ASD-affected families and confirmed an excess of genic deletions and duplications in affected versus control groups (1.41-fold, p = 1.0 × 10(-5)) and an increase in affected subjects carrying exonic pathogenic CNVs overlapping known loci associated with dominant or X-linked ASD and intellectual disability (odds ratio = 12.62, p = 2.7 × 10(-15), ∼3% of ASD subjects). Pathogenic CNVs, often showing variable expressivity, included rare de novo and inherited events at 36 loci, implicating ASD-associated genes (CHD2, HDAC4, and GDI1) previously linked to other neurodevelopmental disorders, as well as other genes such as SETD5, MIR137, and HDAC9. Consistent with hypothesized gender-specific modulators, females with ASD were more likely to have highly penetrant CNVs (p = 0.017) and were also overrepresented among subjects with fragile X syndrome protein targets (p = 0.02). Genes affected by de novo CNVs and/or loss-of-function single-nucleotide variants converged on networks related to neuronal signaling and development, synapse function, and chromatin regulation.
The American Journal of Human Genetics 04/2014; · 11.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To identify common variants influencing colorectal cancer (CRC) risk, we performed a meta-analysis of five genome-wide association studies, comprising 5,626 cases and 7,817 controls of European descent. We conducted replication of top ranked SNPs in additional series totalling 14,037 cases and 15,937 controls, identifying a new CRC risk locus at 10q24.2 (rs1035209; OR=1.13, P=4.54x10(-11)). We also performed meta-analysis of our studies, with previously published data, of several recently purported CRC risk loci. We failed to find convincing evidence for a previously reported genome-wide association at rs11903757 (2q32.3). Of the three additional loci for which evidence of an association in Europeans has been previously described we failed to show an association between rs59336 (12q24.21) and CRC risk. However, for the other two SNPs, our analyses demonstrated new, formally-significant associations with CRC. These are rs3217810 intronic in CCND2 (12p13.32; OR=1.19, P=2.16x10(-10)) and rs10911251 near LAMC1 (1q25.3; OR=1.09, P=1.75x10(-8)). Additionally, we found some evidence to support a relationship between, rs647161, rs2423297 and rs10774214 and CRC risk originally identified in East Asians in our European datasets. Our findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to CRC.
Human Molecular Genetics 04/2014; · 7.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dietary factors, including meat, fruits, vegetables and fiber, are associated with colorectal cancer; however, there is limited information as to whether these dietary factors interact with genetic variants to modify risk of colorectal cancer. We tested interactions between these dietary factors and approximately 2.7 million genetic variants for colorectal cancer risk among 9,287 cases and 9,117 controls from ten studies. We used logistic regression to investigate multiplicative gene-diet interactions, as well as our recently developed Cocktail method that involves a screening step based on marginal associations and gene-diet correlations and a testing step for multiplicative interactions, while correcting for multiple testing using weighted hypothesis testing. Per quartile increment in the intake of red and processed meat were associated with statistically significant increased risks of colorectal cancer and vegetable, fruit and fiber intake with lower risks. From the case-control analysis, we detected a significant interaction between rs4143094 (10p14/near GATA3) and processed meat consumption (OR = 1.17; p = 8.7E-09), which was consistently observed across studies (p heterogeneity = 0.78). The risk of colorectal cancer associated with processed meat was increased among individuals with the rs4143094-TG and -TT genotypes (OR = 1.20 and OR = 1.39, respectively) and null among those with the GG genotype (OR = 1.03). Our results identify a novel gene-diet interaction with processed meat for colorectal cancer, highlighting that diet may modify the effect of genetic variants on disease risk, which may have important implications for prevention.
[Show abstract][Hide abstract] ABSTRACT: Early-onset breast cancer (EOBC) causes substantial loss of life and productivity, creating a major burden among women worldwide. We analyzed 1,265,548 Hapmap3 SNPs among a discovery set of 3,523 EOBC incident case and 2,702 population control women aged <=51 years. The SNPs with smallest P-values were examined in a replication set of 3,470 EOBC case and 5,475 control women. We also tested EOBC association with 19,684 genes by annotating each gene with putative functional SNPs, and then combining their P-values to obtain a gene-based P-value. We examined the gene with smallest P-value for replication in 1,145 breast cancer case and 1,142 control women. The combined discovery and replication sets identified 72 new SNPs associated with EOBC (P<4x10-8) located in six genomic regions previously reported to contain SNPs associated largely with later-onset breast cancer (LOBC). SNP rs2229882 and 10 other SNPs on chromosome 5q11.2 remained associated (P<6x10-4) after adjustment for the strongest published SNPs in the region. Thirty-two of the 82 currently known LOBC SNPs were associated with EOBC (P<0.05). Low power is likely responsible for the remaining 50 unassociated known LOBC SNPs. The gene-based analysis identified an association between breast cancer and the phosphofructokinase-muscle (PFKM) gene on chromosome 12q13.11 that met the genomewide gene-based threshold of 2.5x10-In conclusion, EOBC and LOBC appear to have similar genetic etiologies; the 5q11.2 region may contain multiple distinct breast cancer loci; and the PFKM gene region is worthy of further investigation. These findings should enhance our understanding of the etiology of breast cancer.
Cancer Epidemiology Biomarkers & Prevention 02/2014; · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Genome-wide association studies (GWAS) of colorectal cancer (CRC) have led to the identification of a number of common variants associated with modest risk. Several risk variants map within the vicinity of TGFβ/BMP signaling pathway genes, including rs4939827 within an intron of SMAD7 at 18q21.1. A previous study implicated a novel SNP (novel 1 or rs58920878) as a functional variant within an enhancer element in SMAD7 intron 4. In this study, we show that four SNPs including novel 1 (rs6507874, rs6507875, rs8085824, and rs58920878) in linkage disequilibrium (LD) with the index SNP rs4939827 demonstrate allele-specific enhancer effects in a large, multi-component enhancer of SMAD7. All four SNPs demonstrate allele-specific protein binding to nuclear extracts of CRC cell lines. Furthermore, some of the risk-associated alleles correlate with increased expression of SMAD7 in normal colon tissues. Finally, we show that the enhancer is responsive to BMP4 stimulation. Taken together, we propose that the associated CRC risk at 18q21.1 is due to four functional variants that regulate SMAD7 expression and potentially perturb a BMP negative feedback loop in TGFβ/BMP signaling pathways.
PLoS ONE 01/2014; 9(11):e111914. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The genetic basis of sporadic colorectal cancer (CRC) is not well explained by known risk polymorphisms. Here we perform a meta-analysis of two genome-wide association studies in 2,627 cases and 3,797 controls of Japanese ancestry and 1,894 cases and 4,703 controls of African ancestry, to identify genetic variants that contribute to CRC susceptibility. We replicate genome-wide statistically significant associations (P<5 × 10(-8)) in 16,823 cases and 18,211 controls of European ancestry. This study reveals a new pan-ethnic CRC risk locus at 10q25 (rs12241008, intronic to VTI1A; P=1.4 × 10(-9)), providing additional insight into the aetiology of CRC and highlighting the value of association mapping in diverse populations.
[Show abstract][Hide abstract] ABSTRACT: We scanned through the genomes of 29,141 African Americans, searching for
loci where the average proportion of African ancestry deviates significantly
from the genome-wide average. We failed to find any genome-wide significant
deviations, and conclude that any selection in African Americans since
admixture is sufficiently weak that it falls below the threshold of our power
to detect it using a large sample size. These results stand in contrast to the
findings of a recent study of selection in African Americans. That study, which
had 15 times fewer samples, reported six loci with significant deviations. We
show that the discrepancy is likely due to insufficient correction for multiple
hypothesis testing in the previous study. The same study reported 14 loci that
showed greater population differentiation between African Americans and
Nigerian Yoruba than would be expected in the absence of natural selection.
Four such loci were previously shown to be genome-wide significant and likely
to be affected by selection, but we show that most of the 10 additional loci
are likely to be false positives. Additionally, the most parsimonious
explanation for the loci that have significant evidence of unusual
differentiation in frequency between Nigerians and Africans Americans is
selection in Africa prior to their forced migration to the Americas.
[Show abstract][Hide abstract] ABSTRACT: Genome-wide association studies (GWAS) of colorectal cancer (CRC) have identified a number of common variants associated with modest risk, including rs3802842 at chromosome 11q23.1. Several genes map to this region but rs3802842 does not map to any known transcribed or regulatory sequences. We reasoned, therefore, that rs3802842 is not the functional SNP, but is in linkage disequilibrium (LD) with a functional SNP(s). We performed ChIP-seq for histone modifications in SW480 and HCT-116 CRC cells, and incorporated ChIP-seq and DNase 1 hypersensitivity data available through ENCODE within a 137 kb genomic region containing rs3802842 on 11q23.1. We identified SNP rs10891246 in LD with rs3802842 that mapped within a bidirectional promoter region of genes C11orf92 and C11orf93. Following mutagenesis to the risk allele, the promoter demonstrated lower levels of reporter gene expression. A second SNP rs7130173 was identified in LD with rs3802842 that mapped to a candidate enhancer region, which showed strong unidirectional activity in both HCT-116 and SW480 CRC cells. The risk allele of rs7130173 demonstrated reduced enhancer activity compared to the common allele, and reduced nuclear protein binding affinity in electromobility shift assays compared with the common allele suggesting differential transcription factor binding. SNPs rs10891246 and rs7130173 are on the same haplotype, and eQTL analyses of neighboring genes implicate C11orf53, C11orf92 and C11orf93 as candidate target genes. These data imply that rs10891246 and rs7130173 are functional SNPs mapping to 11q23.1 and that C11orf53, C11orf92 and C11orf93 represent novel candidate target genes involved in CRC etiology.
Human Molecular Genetics 11/2013; · 7.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: It is widely accepted that chronic inflammation plays a role in the etiology of colorectal cancer. Using a two-stage design, we examined the associations between colorectal cancer and common variation in 37 key genes in the inflammation and innate immunity pathways. Methods: In the discovery stage, 2,322 discordant sibships (2,535 cases, 3,915 sibling controls) from the Colorectal Cancer Family Registry were genotyped for over 600 tagSNPs and 99 SNPs were selected for further examination based on strength of association. In the second stage, 351 SNPs tagging gene regions covered by the 99 SNPs were tested in 4,783 Multiethnic Cohort subjects (2,153 cases, 2,630 controls). Results: The association between rs9858822 in the PPARG gene and colorectal cancer was statistically significant at the end of the second stage (odds ratio per allele = 1.36, Bonferroni-adjusted P = 0.045), based on the "effective" number of markers in Stage 2 (n = 306). The risk allele C was common (frequency 0.3) in African Americans but rare (frequency < 0.03) in whites, Japanese Americans, Latinos and Native Hawaiians. No statistically significant heterogeneity of effects across race/ethnicity, BMI levels, regular aspirin use or pack-years of smoking was detected for this SNP. Suggestive associations were also observed for several SNPs in close vicinity to rs9858822. Conclusions: Our results provide new evidence of association between PPARG variants and colorectal cancer risk. Impact: Further replication in independent samples is warranted.
Cancer Epidemiology Biomarkers & Prevention 09/2013; · 4.56 Impact Factor