Petersen, Gloria M.

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)

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]

Abstract Multiple genome-wide association studies have identified several susceptibility variants for colon cancer at 8q24. However, the functional roles of these variants have yet to be elucidated. Here, we evaluated the potential role of these markers in tumor progression and examined association with commonly observed structural abnormalities in this region, c-MYC amplification and chromosome fragility at FRA8C and FRA8D. We first replicated the previously reported association by testing 1,178 cases and 1,009 clinic-based controls with eight markers localized to three specific regions at 8q24. We observed significant associations with colon cancer risk with markers rs13254738 (ordinal odds ratio, 0.82; 95% confidence interval, 0.072-0.94; Ptrend = 0.0037) and rs6983267 (ordinal odds ratio, 1.17; 95% confidence interval, 1.03-1.32, Ptrend = 0.013). Survival analysis was done using a separate set of 460 cases to evaluate the clinical significance of these markers. Overall, univariate analysis did not detect survival differences for any of the markers. We also tested a subset of the 460 cases (n = 380) for structural abnormalities at or near the c-MYC locus using fluorescence in situ hybridization analysis. Furthermore, we evaluated a small number of cases homozygous for the rs6983267 alleles to test for differences in fragile site induction. None of the 8q markers correlated with amplification at the c-MYC locus as detected by fluorescence in situ hybridization, and no clear pattern of breakage was observed at the FRA8C and FRA8D sites. In this study, we confirm the association for several single nucleotide polymorphisms at 8q24 in colon cancer but have not detected any structural role relating to c-MYC amplification or chromosomal fragility. Finally, these risk alleles do not seem to be associated with survival. (Cancer Epidemiol Biomarkers Prev 2009;18(9):2492–500)

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)

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)

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.

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)

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 Inactivating mutations in several genes that encode components of the DNA repair machinery have been associated with an increased risk of breast cancer. To assess whether alterations in other DNA repair genes contribute to breast cancer and to further determine the relevance of these genes to pancreatic cancer, we performed mutational analysis of 32 DNA double-strand break repair genes in genomic DNA from 38 breast tumors, 48 pancreatic tumors, and 10 non-BRCA1/BRCA2 hereditary breast cancer patients. A total of 494 coding exons were screened by denatured high-performance liquid chromatography and direct DNA sequencing. Two inactivating mutations were identified in breast tumor samples, a germline single-nucleotide deletion in POLQ (c.3605delT) and a somatic nonsense change in PRKDC (c.2408C>A, p.Ser803X). Two germline-inactivating mutations in RAD50 (c.1875C>G, p.Tyr625X and IVS14+1G>A) were also detected in separate pancreatic tumor samples. In addition, 35 novel nonsynonymous amino acid substitutions, resulting from two in-frame deletions and 33 single nucleotide alterations, were identified. Seven of these were predicted to influence protein function. A separate analysis of the CLSPN c.3839C>T (rs35490896) variant that was observed more frequently in breast tumors than in pancreatic tumors or normal controls failed to detect a significant association with breast cancer risk in a Mayo Clinic breast cancer case-control study. In conclusion, this screen of DNA repair genes implicates PRKDC and POLQ as candidate tumor suppressor genes involved in breast cancer and suggests that inactivating mutations in RAD50 predispose to pancreatic cancer as well as breast cancer. [Cancer Res 2008;68(4):971–5]