Abstract Background: Mitosis is a highly regulated process that serves to ensure the fidelity of cell division. The disruption of mitotic regulators leading to aneuploidy and polyploidy is commonly observed in cancer cells. Single nucleotide polymorphisms (SNP) in regulators of mitosis may promote chromosome missegregation and influence pancreatic cancer and/or survival. Methods: Thirty-four SNPs, previously associated with breast cancer risk, from 33 genes involved in the regulation of mitosis, were investigated for associations with pancreatic cancer risk in 1,143 Caucasian patients with pancreatic adenocarcinoma and 1,097 unaffected controls from the Mayo Clinic. Associations with survival from pancreatic cancer were also assessed using 1,030 pancreatic cancer cases with known outcome. Results: Two SNPs in the APC (rs2431238) and NIN (rs10145182) loci, of 34 examined, were significantly associated with pancreatic cancer risk (P = 0.035 and P = 0.038, respectively). Further analyses of individuals categorized by smoking and body mass index identified several SNPs displaying significant associations (P < 0.05) with pancreatic cancer risk, including APC rs2431238 in individuals with high body mass index (≥30; P = 0.031) and NIN rs10145182 in ever smokers (P = 0.01). In addition, survival analyses detected significant associations between SNPs in EIF3S10 and overall survival (P = 0.009), SNPs from five genes and survival in resected cancer cases (P < 0.05), and SNPs from two other genes (P < 0.05) and survival of locally advanced cancer cases. Conclusion: Common variation in genes encoding regulators of mitosis may independently influence pancreatic cancer susceptibility and survival. Cancer Epidemiol Biomarkers Prev; 19(1); 251–7
Association of Breast Cancer Susceptibility Variants with Risk of Pancreatic Cancer
AbstractBackground: A number of susceptibility genes are common to breast and pancreatic cancer. Recently, several breast cancer susceptibility loci have been identified through genome-wide association studies. Here we evaluated possible associations between these single nucleotide polymorphisms (SNP) and pancreatic cancer risk.Methods: Ten SNPs from FGFR2, TOX3, MAP3K1, H19, LSP1, chromosome 8q24, CASP8, and LUM were investigated for associations with pancreatic cancer risk following genotyping in 1,143 Caucasian individuals with pancreatic adenocarcinoma and 1,097 unaffected controls from a clinic-based pancreatic cancer case-control study.Results: CASP8 rs1045485 [odds ratio (OR), 0.78; 95% confidence interval (95% CI), 0.65-0.9; P = 0.005] and MAP3K1 rs889312 (OR, 0.85; 95% CI, 0.74-0.97; P = 0.017) showed evidence of association with risk of pancreatic cancer. The CASP8 rs1045485 association was evident in ever smokers (P = 0.002), but not in nonsmokers (P = 0.55), and the effect was strongest in heavy smokers (OR, 0.52; 95% CI, 0.29-0.93; P = 0.03). In contrast the MAP3K1 rs889312 association was only evident in nonsmokers (OR, 0.78; 95% CI, 0.64-0.95; P = 0.01). In addition, evaluation of the influence of the 10 SNPs on survival detected significant associations between outcome for locally advanced pancreatic cancer cases and both 8q rs6983561 (P = 0.045) and LUM rs2268578 (P = 0.02).Conclusion: Association studies in a large pancreatic case-control study indicate that SNPs associated with breast cancer may also be associated with pancreatic cancer susceptibility and survival. (Cancer Epidemiol Biomarkers Prev 2009;18(11):3044–8)
Haplotype and Cell Proliferation Analyses of Candidate Lung Cancer Susceptibility Genes on Chromosome 15q24-25.1
Abstract Recent genome-wide association studies have linked the chromosome 15q24-25.1 locus to nicotine addiction and lung cancer susceptibility. To refine the 15q24-25.1 locus, we performed a haplotype-based association analysis of 194 familial lung cases and 219 cancer-free controls from the Genetic Epidemiology of Lung Cancer Consortium (GELCC) collection, and used proliferation and apoptosis analyses to determine which gene(s) in the 15q24-25.1 locus mediates effects on lung cancer cell growth in vitro. We identified two distinct subregions, hapL (P = 3.20 × 10−6) and hapN (P = 1.51 × 10−6), which were significantly associated with familial lung cancer. hapL encompasses IREB2, LOC123688, and PSMA4, and hapN encompasses the three nicotinic acetylcholine receptor subunit genes CHRNA5, CHRNA3, and CHRNB4. Examination of the genes around hapL revealed that PSMA4 plays a role in promoting cancer cell proliferation. PSMA4 mRNA levels were increased in lung tumors compared with normal lung tissues. Down-regulation of PSMA4 expression decreased proteasome activity and induced apoptosis. Proteasome dysfunction leads to many diseases including cancer, and drugs that inhibit proteasome activity show promise as a form of cancer treatment. Genes around hapN were also investigated, but did not show any direct effect on lung cancer cell proliferation. We concluded that PSMA4 is a strong candidate mediator of lung cancer cell growth, and may directly affect lung cancer susceptibility through its modulation of cell proliferation and apoptosis. [Cancer Res 2009;69(19):7844–50]
Polymorphic Variants in Hereditary Pancreatic Cancer Genes Are Not Associated with Pancreatic Cancer Risk
Abstract Background: Inherited risk of pancreatic cancer has been associated with mutations in several genes, including BRCA2, CDKN2A (p16), PRSS1, and PALB2. We hypothesized that common variants in these genes, single nucleotide polymorphisms (SNP), may also influence risk for pancreatic cancer development. Methods: A clinic-based case-control study in non-Hispanic white persons compared 1,143 patients with pancreatic adenocarcinoma with 1,097 healthy controls. Twenty-eight genes directly and indirectly involved in the Fanconi/BRCA pathway (includes BRCA1, BRCA2, and PALB2) were identified and 248 tag SNPs were selected. In addition, 11 SNPs in CDKN2A, PRSS1, and PRSS2 were selected. Association studies were done at the gene level by principal components analysis, whereas recursive partitioning analysis was used to investigate pathway effects. At the individual SNP level, adjusted additive, dominant, and recessive models were investigated, and gene-environment interactions were also assessed. Results: Gene level analyses showed no significant association of any genes with altered pancreatic cancer risk. Multiple single SNP analyses showed associations, which will require replication. Exploratory pathway analyses by recursive partitioning showed no association between SNPs and risk for pancreatic cancer. Conclusion: In a candidate gene and pathway SNP association study analysis, common variations in the Fanconi/BRCA pathway and other candidate familial pancreatic cancer genes are not associated with risk for pancreatic cancer. Cancer Epidemiol Biomarkers Prev 2009;18(9):2549–52)
Nucleotide Excision Repair Pathway Polymorphisms and Pancreatic Cancer Risk: Evidence for role of MMS19L
Abstract Background: Nucleotide excision repair is a vital response to DNA damage, including damage from tobacco exposure. Single nucleotide polymorphisms (SNP) in the nucleotide excision repair pathway may encode alterations that affect DNA repair function and therefore influence the risk of pancreatic cancer development. Methods: A clinic-based case-control study in non-Hispanic white persons compared 1,143 patients with pancreatic adenocarcinoma with 1,097 healthy controls. Twenty-seven genes directly and indirectly involved in the nucleotide excision repair pathway were identified and 236 tag-SNPs were selected from 26 of these (one had no SNPs identified). Association studies were done at the gene level by principal components analysis, whereas recursive partitioning analysis was utilized to identify potential gene-gene and gene-environment interactions within the pathway. At the individual SNP level, adjusted additive, dominant, and recessive models were investigated, and gene-environment interactions were also assessed. Results: Gene level analyses showed an association of the MMS19L genotype (chromosome 10q24.1) with altered pancreatic cancer risk (P = 0.023). Haplotype analysis of MMS19L also showed a significant association (P = 0.0132). Analyses of seven individual SNPs in this gene showed both protective and risk associations for minor alleles, broadly distributed across patient subgroups defined by smoking status, sex, and age. Conclusion: In a candidate pathway SNP association study analysis, common variation in a nucleotide excision repair gene, MMS19L, was associated with the risk of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1295–302)
Fine Mapping of Chromosome 6q23-25 Region in Familial Lung Cancer Families Reveals
RGS17
as a Likely Candidate Gene
Abstract Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. Conclusion: RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25.
Mitochondrial Genetic Polymorphisms Do Not Predict Survival in Patients with Pancreatic Cancer
Abstract Pancreatic cancer is a highly lethal malignancy, and the majority of patients succumb to the disease within 2 years. We evaluated the role of variants of mitochondrial DNA and mitochondrial haplogroups in predicting prognosis of patients with pancreatic cancer. A total of 24 mitochondrial single nucleotide polymorphisms were genotyped in 990 patients with pancreatic cancer. After adjusting for covariates and multiple comparisons, no association between any of the mitochondrial single nucleotide polymorphisms or haplogroups and survival was observed. (Cancer Epidemiol Biomarkers Prev 2008;17(9):2512–3)
Polymorphisms in DNA Repair Genes, Smoking, and Pancreatic Adenocarcinoma Risk
Abstract Base excision repair and nucleotide excision repair are vital responses to multiple types of DNA damage, including damage from tobacco exposure. Single-nucleotide polymorphisms (SNP) in these pathways may affect DNA repair capacity and therefore influence risk for cancer development. We performed a clinic-based, case-control study comprising 481 consecutive patients with confirmed pancreatic adenocarcinoma and 625 healthy controls. Allele and genotype frequencies for 16 SNPs in DNA repair genes ERCC1, XPD/ERCC2, XPC, XPF/ERCC4, OGG1, and XRCC1 were compared after adjusting for age, sex, and smoking history. Subgroup analysis by sex and smoking history was performed. Carriers of one or two XPF/ERCC4 minor alleles at R415Q had decreased risk of pancreatic adenocarcinoma compared with those who had two major alleles [odds ratio (OR), 0.59; 95% confidence interval (95% CI), 0.40–0.85]. Heavy smokers (>40 pack-years) had increased risk for cancer if they were carriers of at least one minor allele for XPD/ERCC2 at D312N (OR, 2.78; 95% CI, 1.28–6.04) or D711D (OR, 2.19; 95% CI, 1.01–4.73). No other significant differences in risk were identified. Minor alleles in DNA repair genes XPF/ERCC4 and XPD/ERCC2 were associated with altered risk for pancreatic cancer. [Cancer Res 2008;68(12):4928–35]
Abstract The rationale behind gene-disease association studies is that genetic variants (polymorphisms) result in alterations in intermediate phenotypes. However, genotype-phenotype correlations have not been established for most polymorphisms. In this study, we correlated genotype data of genes involved in the nucleotide excision repair pathway with mutagen sensitivity phenotype, quantified by benzo(a)pyrene diol epoxide (BPDE)-induced chromatid breaks in peripheral blood lymphocytes in 422 healthy subjects recruited into a twin study that included 138 pairs of monozygotic twins, 51 pairs of dizygotic twins, and 44 siblings. Among a panel of single nucleotide polymorphisms examined, we found that BPDE sensitivity was modified by individual polymorphisms in XPC, RAD23B, and XPA genes. Specific haplotypes and diplotypes of XPC also modified BPDE sensitivity profiles. In addition, a more consistent and stronger correlation was observed between mutagen sensitivity phenotype and the combination of multiple polymorphisms in the nucleotide excision repair pathway. Specifically, when XPC-PAT, XPC Lys939Gln, XPA A23G, and RAD23B Val249Ala were analyzed together, we observed a significant dose-response relationship between increasing mutagen sensitivity with increasing number of adverse alleles: mutagen sensitivity for those carrying zero to two, three to five, and six or more adverse alleles were 0.64, 0.68, and 1.06, respectively (P for trend = 0.008), and the results remained significant after adjusting for multiple comparisons. Using individuals carrying zero to two adverse alleles as the reference group, the risks of being mutagen sensitive (mutagen sensitivity values greater than the median) were 1.05 (95% confidence interval, 0.68-1.64) and 4.48 (95% confidence interval, 1.21-16.61) for those carrying three to five and six or more adverse alleles, respectively. Analyses of the effects of genotype combinations yielded similar results. These findings underscore the importance of assessing the collective effects of a panel of polymorphisms in the same pathway in modulating mutagen sensitivity. As risk assessment for cancer risk is moving toward a multigenic pathway-based approach, future genotype-phenotype correlation studies should also investigate the combined effects of multiple genetic variants. (Cancer Epidemiol Biomarkers Prev 2007;16(10):2065–71)