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1.
Cancer Epidemiol Biomarkers Prev ; 28(11): 1868-1875, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31427306

RESUMO

BACKGROUND: Leukocyte telomere length has been associated with risk of subsequent pancreatic cancer. Few prospective studies have evaluated the association of prediagnostic leukocyte telomere length with pancreatic cancer survival. METHODS: We prospectively examined the association of prediagnostic leukocyte telomere length with overall survival (OS) time among 423 participants diagnosed with pancreatic adenocarcinoma between 1984 and 2008 within the Health Professionals Follow-up Study, Nurses' Health Study, Physicians' Health Study, and Women's Health Initiative. We measured prediagnostic leukocyte telomere length in banked blood samples using quantitative PCR. Cox proportional hazards models were used to estimate HRs for OS with adjustment for potential confounders. We also evaluated 10 SNPs at the telomerase reverse transcriptase locus. RESULTS: Shorter prediagnostic leukocyte telomere length was associated with reduced OS among patients with pancreatic cancer (P trend = 0.04). The multivariable-adjusted HR for OS comparing the lowest with highest quintiles of leukocyte telomere length was 1.39 (95% confidence interval, 1.01-1.93), corresponding to a 3-month difference in median OS time. In an analysis excluding cases with blood collected within 2 years of cancer diagnosis, the association was moderately stronger (HR, 1.55; 95% confidence interval, 1.09-2.21; comparing the lowest with highest quintiles; P trend = 0.01). No prognostic association or effect modification for the prognostic association of prediagnostic leukocyte telomere length was noted in relation to the studied SNPs. CONCLUSIONS: Prediagnostic leukocyte telomere length was associated with pancreatic cancer survival. IMPACT: Prediagnostic leukocyte telomere length can be a prognostic biomarker in pancreatic cancer.

2.
Pancreas ; 48(7): 894-903, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31268978

RESUMO

OBJECTIVE: The KRAS gene is the most frequently mutated gene in pancreatic cancer, and no successful anti-Ras therapy has been developed. Gastrin has been shown to stimulate pancreatic cancer in an autocrine fashion. We hypothesized that reactivation of the peptide gastrin collaborates with KRAS during pancreatic carcinogenesis. METHODS: LSL-Kras; P48-Cre (KC) mutant KRAS transgenic mice were crossed with gastrin-KO (GKO) mice to develop GKO/KC mice. Pancreata were examined for 8 months for stage of pancreatic intraepithelial neoplasia lesions, inflammation, fibrosis, gastrin peptide, and microRNA expression. Pancreatic intraepithelial neoplasias from mice were collected by laser capture microdissection and subjected to reverse-phase protein microarray, for gastrin and protein kinases associated with signal transduction. Gastrin mRNA was measured by RNAseq in human pancreatic cancer tissues and compared to that in normal pancreas. RESULTS: In the absence of gastrin, PanIN progression, inflammation, and fibrosis were significantly decreased and signal transduction was reversed to the canonical pathway with decreased KRAS. Gastrin re-expression in the PanINs was mediated by miR-27a. Gastrin mRNA expression was significantly increased in human pancreatic cancer samples compared to normal human pancreas controls. CONCLUSIONS: This study supports the mitogenic role of gastrin in activation of KRAS during pancreatic carcinogenesis.

3.
Int J Cancer ; 144(6): 1367-1378, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30468251

RESUMO

Altered regulation of endoplasmic reticulum (ER) homeostasis has been implicated in many cancers and has recently become a therapeutic and chemosensitization target of interest. We have identified Cleft Lip and Palate Transmembrane 1-Like (CLPTM1L)/Cisplatin Resistance Related Protein 9 (CRR9) as an ER stress related mediator of cytoprotection in pancreatic cancer. We recently demonstrated that CLPTM1L is highly expressed in pancreatic ductal adenocarcinoma and associated with poor outcome. Furthermore, we have discovered that CLPTM1L interacts with phosphoinositol-3-kinase-alpha at the tumor cell surface and causes up-regulation of Bcl-xL and pAkt mediated survival signaling. Here, we demonstrate surface relocalization and survival signaling by CLPTM1L triggered by endoplasmic reticular (ER) stress. We demonstrate the interaction of CLPTM1L with the central ER stress survival mediator, Glucose Regulated Protein 78 (GRP78)/Binding Immunoglobulin Protein (BiP) and PI3K-alpha /p110α. This interaction and surface relocalization of CLPTM1L and GRP78 is induced by ER stress, including that caused by treatment with gemcitabine. We demonstrate that the extracellular loop of CLPTM1L is required for gemcitabine resistance and interaction with GRP78. This interaction and the chemoresistance effect conferred by this pathway is targetable with our recently developed inhibitory CLPTM1L antibodies, which may represent novel modalities of chemosensitization and treatment of pancreatic adenocarcinoma. Anchorage independent growth, GRP78-mediated chemoresistance, and Akt phosphorylation were abrogated by inhibition of CLPTM1L. These findings demonstrate a novel and potentially targetable mechanism of cytoprotection and chemoresistance in pancreatic tumors.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Proteínas de Choque Térmico/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Antineoplásicos/uso terapêutico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/cirurgia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Proteínas de Choque Térmico/antagonistas & inibidores , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Fosforilação , Cultura Primária de Células , Domínios Proteicos , Transdução de Sinais/efeitos dos fármacos , Resposta a Proteínas não Dobradas/efeitos dos fármacos
4.
Genome Res ; 28(11): 1621-1635, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30333196

RESUMO

Most expression quantitative trait locus (eQTL) studies to date have been performed in heterogeneous tissues as opposed to specific cell types. To better understand the cell-type-specific regulatory landscape of human melanocytes, which give rise to melanoma but account for <5% of typical human skin biopsies, we performed an eQTL analysis in primary melanocyte cultures from 106 newborn males. We identified 597,335 cis-eQTL SNPs prior to linkage disequilibrium (LD) pruning and 4997 eGenes (FDR < 0.05). Melanocyte eQTLs differed considerably from those identified in the 44 GTEx tissue types, including skin. Over a third of melanocyte eGenes, including key genes in melanin synthesis pathways, were unique to melanocytes compared to those of GTEx skin tissues or TCGA melanomas. The melanocyte data set also identified trans-eQTLs, including those connecting a pigmentation-associated functional SNP with four genes, likely through cis-regulation of IRF4 Melanocyte eQTLs are enriched in cis-regulatory signatures found in melanocytes as well as in melanoma-associated variants identified through genome-wide association studies. Melanocyte eQTLs also colocalized with melanoma GWAS variants in five known loci. Finally, a transcriptome-wide association study using melanocyte eQTLs uncovered four novel susceptibility loci, where imputed expression levels of five genes (ZFP90, HEBP1, MSC, CBWD1, and RP11-383H13.1) were associated with melanoma at genome-wide significant P-values. Our data highlight the utility of lineage-specific eQTL resources for annotating GWAS findings, and present a robust database for genomic research of melanoma risk and melanocyte biology.


Assuntos
Predisposição Genética para Doença , Melanócitos/metabolismo , Melanoma/genética , Locos de Características Quantitativas , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Transporte/genética , Células Cultivadas , Hemeproteínas/genética , Humanos , Fatores Reguladores de Interferon/genética , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único
5.
Carcinogenesis ; 39(8): 1056-1067, 2018 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-29800239

RESUMO

Diets with high inflammatory potential are suspected to increase risk for pancreatic cancer (PC). Using pooled analyses, we examined whether this association applies to populations from different geographic regions and population subgroups with varying risks for PC, including variation in ABO blood type. Data from six case-control studies (cases, n = 2414; controls, n = 4528) in the Pancreatic Cancer Case-Control Consortium (PanC4) were analyzed, followed by replication in five nested case-control studies (cases, n = 1268; controls, n = 4215) from the Pancreatic Cancer Cohort Consortium (PanScan). Two polymorphisms in the ABO locus (rs505922 and rs8176746) were used to infer participants' blood types. Dietary questionnaire-derived nutrient/food intake was used to compute energy-adjusted dietary inflammatory index (E-DII®) scores to assess inflammatory potential of diet. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable-adjusted logistic regression. Higher E-DII scores, reflecting greater inflammatory potential of diet, were associated with increased PC risk in PanC4 [ORQ5 versus Q1=2.20, 95% confidence interval (CI) = 1.85-2.61, Ptrend < 0.0001; ORcontinuous = 1.20, 95% CI = 1.17-1.24], and PanScan (ORQ5 versus Q1 = 1.23, 95% CI = 0.92-1.66, Ptrend = 0.008; ORcontinuous = 1.09, 95% CI = 1.02-1.15). As expected, genotype-derived non-O blood type was associated with increased PC risk in both the PanC4 and PanScan studies. Stratified analyses of associations between E-DII quintiles and PC by genotype-derived ABO blood type did not show interaction by blood type (Pinteraction = 0.10 in PanC4 and Pinteraction=0.13 in PanScan). The results show that consuming a pro-inflammatory diet and carrying non-O blood type are each individually, but not interactively, associated with increased PC risk.


Assuntos
Sistema do Grupo Sanguíneo ABO/genética , Comportamento Alimentar/fisiologia , Inflamação/imunologia , Neoplasias Pancreáticas/sangue , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Inflamação/complicações , Masculino , Pessoa de Meia-Idade , Pâncreas/imunologia , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/imunologia , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Fatores de Risco , Inquéritos e Questionários/estatística & dados numéricos
7.
Nature ; 554(7693): 533-537, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29443959

RESUMO

Chronic inflammation increases the risk of developing one of several types of cancer. Inflammatory responses are currently thought to be controlled by mechanisms that rely on transcriptional networks that are distinct from those involved in cell differentiation. The orphan nuclear receptor NR5A2 participates in a wide variety of processes, including cholesterol and glucose metabolism in the liver, resolution of endoplasmic reticulum stress, intestinal glucocorticoid production, pancreatic development and acinar differentiation. In genome-wide association studies, single nucleotide polymorphisms in the vicinity of NR5A2 have previously been associated with the risk of pancreatic adenocarcinoma. In mice, Nr5a2 heterozygosity sensitizes the pancreas to damage, impairs regeneration and cooperates with mutant Kras in tumour progression. Here, using a global transcriptomic analysis, we describe an epithelial-cell-autonomous basal pre-inflammatory state in the pancreas of Nr5a2+/- mice that is reminiscent of the early stages of pancreatitis-induced inflammation and is conserved in histologically normal human pancreases with reduced expression of NR5A2 mRNA. In Nr5a2+/-mice, NR5A2 undergoes a marked transcriptional switch, relocating from differentiation-specific to inflammatory genes and thereby promoting gene transcription that is dependent on the AP-1 transcription factor. Pancreatic deletion of Jun rescues the pre-inflammatory phenotype, as well as binding of NR5A2 to inflammatory gene promoters and the defective regenerative response to damage. These findings support the notion that, in the pancreas, the transcriptional networks involved in differentiation-specific functions also suppress inflammatory programmes. Under conditions of genetic or environmental constraint, these networks can be subverted to foster inflammation.


Assuntos
Diferenciação Celular/genética , Regulação da Expressão Gênica , Inflamação/genética , Pâncreas/metabolismo , Pâncreas/patologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Transcriptoma , Células Acinares/metabolismo , Células Acinares/patologia , Animais , Cromatina/genética , Cromatina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Redes Reguladoras de Genes/genética , Genes jun/genética , Heterozigoto , Humanos , Camundongos , Especificidade de Órgãos/genética , Pancreatite/genética , Regiões Promotoras Genéticas/genética , Receptores Citoplasmáticos e Nucleares/deficiência , Receptores Citoplasmáticos e Nucleares/genética , Fator de Transcrição AP-1/metabolismo
8.
Gut ; 67(3): 521-533, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28634199

RESUMO

OBJECTIVE: To elucidate the genetic architecture of gene expression in pancreatic tissues. DESIGN: We performed expression quantitative trait locus (eQTL) analysis in histologically normal pancreatic tissue samples (n=95) using RNA sequencing and the corresponding 1000 genomes imputed germline genotypes. Data from pancreatic tumour-derived tissue samples (n=115) from The Cancer Genome Atlas were included for comparison. RESULTS: We identified 38 615 cis-eQTLs (in 484 genes) in histologically normal tissues and 39 713 cis-eQTL (in 237 genes) in tumour-derived tissues (false discovery rate <0.1), with the strongest effects seen near transcriptional start sites. Approximately 23% and 42% of genes with significant cis-eQTLs appeared to be specific for tumour-derived and normal-derived tissues, respectively. Significant enrichment of cis-eQTL variants was noted in non-coding regulatory regions, in particular for pancreatic tissues (1.53-fold to 3.12-fold, p≤0.0001), indicating tissue-specific functional relevance. A common pancreatic cancer risk locus on 9q34.2 (rs687289) was associated with ABO expression in histologically normal (p=5.8×10-8) and tumour-derived (p=8.3×10-5) tissues. The high linkage disequilibrium between this variant and the O blood group generating deletion variant in ABO (exon 6) suggested that nonsense-mediated decay (NMD) of the 'O' mRNA might explain this finding. However, knockdown of crucial NMD regulators did not influence decay of the ABO 'O' mRNA, indicating that a gene regulatory element influenced by pancreatic cancer risk alleles may underlie the eQTL. CONCLUSIONS: We have identified cis-eQTLs representing potential functional regulatory variants in the pancreas and generated a rich data set for further studies on gene expression and its regulation in pancreatic tissues.


Assuntos
Sistema do Grupo Sanguíneo ABO/genética , Expressão Gênica , Pâncreas , Neoplasias Pancreáticas/genética , Locos de Características Quantitativas , RNA Neoplásico/análise , Transcriptoma , Alelos , Cromossomos Humanos Par 9 , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Degradação do RNAm Mediada por Códon sem Sentido , Polimorfismo de Nucleotídeo Único , Sequências Reguladoras de Ácido Nucleico , Análise de Sequência de RNA
9.
Cancer Epidemiol Biomarkers Prev ; 26(10): 1540-1548, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28754795

RESUMO

Background: The higher risk of pancreatic cancer in Ashkenazi Jews compared with non-Jews is only partially explained by the increased frequency of BRCA1 and BRCA2 mutations in Ashkenazi Jews.Methods: We evaluated the impact of 16 established pancreatic cancer susceptibility loci in a case-control sample of American Jews, largely Ashkenazi, including 406 full-Jewish pancreatic cancer patients and 2,332 full-Jewish controls, genotyped as part of the Pancreatic Cancer Cohort and Case-Control Consortium I/II (PanScan I/II), Pancreatic Cancer Case-Control Consortium (PanC4), and Resource for Genetic Epidemiology Research on Adult Health and Aging (GERA) datasets. We compared risk in full-Jewish subjects with risk in part-Jewish; non-Jewish Southern European; and in the combined non-Jewish Eastern, Northern, Southern, and Western European (non-Jewish white European) subjects from the same datasets. Jewish ancestries were genetically identified using seeded Fast principal component analysis. Data were analyzed by unconditional logistic regression, and adjusted for age, sex, and principal components.Results: One SNP on chromosome 13q22.1 (rs9543325; OR, 1.36; 95% confidence interval, 1.16-1.58; P = 10-4.1) was significant in full-Jews. Individual ORs and minor allele frequencies were similar between Jewish and non-Jewish white European subjects. The average ORs across the 16 pancreatic cancer susceptibility loci for full-Jewish, full- plus part-Jewish, non-Jewish Southern European, and non-Jewish white European subjects were 1.25, 1.30, 1.31, and 1.26, respectively.Conclusions: The 16 pancreatic cancer susceptibility loci similarly impact Jewish and non-Jewish white European subjects, both individually and as summary odds.Impact: These 16 pancreatic cancer susceptibility loci likely do not explain the higher risk seen in Ashkenazi Jews. Cancer Epidemiol Biomarkers Prev; 26(10); 1540-8. ©2017 AACR.


Assuntos
Loci Gênicos/genética , Predisposição Genética para Doença/genética , Neoplasias Pancreáticas/genética , Feminino , Humanos , Judeus , Masculino , Neoplasias Pancreáticas/patologia , Estados Unidos
10.
Cancer Epidemiol Biomarkers Prev ; 26(9): 1427-1435, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28637796

RESUMO

Background: Many cancers share specific genetic risk factors, including both rare high-penetrance mutations and common SNPs identified through genome-wide association studies (GWAS). However, little is known about the overall shared heritability across cancers. Quantifying the extent to which two distinct cancers share genetic origin will give insights to shared biological mechanisms underlying cancer and inform design for future genetic association studies.Methods: In this study, we estimated the pair-wise genetic correlation between six cancer types (breast, colorectal, lung, ovarian, pancreatic, and prostate) using cancer-specific GWAS summary statistics data based on 66,958 case and 70,665 control subjects of European ancestry. We also estimated genetic correlations between cancers and 14 noncancer diseases and traits.Results: After adjusting for 15 pair-wise genetic correlation tests between cancers, we found significant (P < 0.003) genetic correlations between pancreatic and colorectal cancer (rg = 0.55, P = 0.003), lung and colorectal cancer (rg = 0.31, P = 0.001). We also found suggestive genetic correlations between lung and breast cancer (rg = 0.27, P = 0.009), and colorectal and breast cancer (rg = 0.22, P = 0.01). In contrast, we found no evidence that prostate cancer shared an appreciable proportion of heritability with other cancers. After adjusting for 84 tests studying genetic correlations between cancer types and other traits (Bonferroni-corrected P value: 0.0006), only the genetic correlation between lung cancer and smoking remained significant (rg = 0.41, P = 1.03 × 10-6). We also observed nominally significant genetic correlations between body mass index and all cancers except ovarian cancer.Conclusions: Our results highlight novel genetic correlations and lend support to previous observational studies that have observed links between cancers and risk factors.Impact: This study demonstrates modest genetic correlations between cancers; in particular, breast, colorectal, and lung cancer share some degree of genetic basis. Cancer Epidemiol Biomarkers Prev; 26(9); 1427-35. ©2017 AACR.


Assuntos
Variação Genética/genética , Estudo de Associação Genômica Ampla/métodos , Neoplasias/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Fatores de Risco
11.
Br J Cancer ; 116(11): 1470-1479, 2017 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-28463958

RESUMO

BACKGROUND: Chromosome 8q24 has emerged as an important genetic susceptibility region for several cancers, including prostate cancer; however, little is known about the contribution of DNA methylation in this region to risk. METHODS: We prospectively evaluated DNA methylation at 8q24 in relation to prostate cancer using pre-diagnostic blood samples from 694 prostate cancer cases (including 172 aggressive cases) and 703 controls in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. We used logistic regression to estimate odds ratios and 95% confidence intervals. RESULTS: Although none remained significant after adjustment for multiple testing (q>0.05), of the 50 CpG sites meeting quality control, we identified 8 sites that were nominally associated with prostate cancer (Ptrend<0.05), including 6 correlated (Spearman ρ: 0.20-0.52) sites in POU5F1B and 2 intergenic sites (most significant site: Chr8:128428897 in POU5F1B, Ptrend=0.01). We also identified two correlated (ρ=0.39) sites in MYC (Chr8:128753187 and Chr8:128753154) that were associated with aggressive (Ptrend=0.02 and 0.03), but not non-aggressive disease (Ptrend=0.70 and 0.20; Pheterogeneity=0.01 and 4.6 × 10-3). These findings persisted after adjustment for the top 8q24 prostate cancer variants in our study. CONCLUSIONS: Although requiring replication, our findings provide some evidence that 8q24 DNA methylation levels may be associated with prostate cancer risk.


Assuntos
Cromossomos Humanos Par 8 , Metilação de DNA , DNA/sangue , Genes myc , Proteínas de Homeodomínio/genética , Neoplasias da Próstata/genética , Idoso , Estudos de Casos e Controles , Ilhas de CpG , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
12.
Nat Commun ; 8: 15034, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28447668

RESUMO

Genome wide association studies (GWAS) have mapped multiple independent cancer susceptibility loci to chr5p15.33. Here, we show that fine-mapping of pancreatic and testicular cancer GWAS within one of these loci (Region 2 in CLPTM1L) focuses the signal to nine highly correlated SNPs. Of these, rs36115365-C associated with increased pancreatic and testicular but decreased lung cancer and melanoma risk, and exhibited preferred protein-binding and enhanced regulatory activity. Transcriptional gene silencing of this regulatory element repressed TERT expression in an allele-specific manner. Proteomic analysis identifies allele-preferred binding of Zinc finger protein 148 (ZNF148) to rs36115365-C, further supported by binding of purified recombinant ZNF148. Knockdown of ZNF148 results in reduced TERT expression, telomerase activity and telomere length. Our results indicate that the association with chr5p15.33-Region 2 may be explained by rs36115365, a variant influencing TERT expression via ZNF148 in a manner consistent with elevated TERT in carriers of the C allele.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Melanoma/genética , Neoplasias Pancreáticas/genética , Neoplasias Cutâneas/genética , Telomerase/genética , Neoplasias Testiculares/genética , Fatores de Transcrição/genética , Alelos , Linhagem Celular Tumoral , Mapeamento Cromossômico , Cromossomos Humanos Par 5 , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Feminino , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Histonas/genética , Histonas/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Melanoma/metabolismo , Melanoma/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Polimorfismo de Nucleotídeo Único , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Telomerase/antagonistas & inibidores , Telomerase/metabolismo , Homeostase do Telômero , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo
13.
JAMA Oncol ; 3(5): 636-651, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28241208

RESUMO

Importance: The causal direction and magnitude of the association between telomere length and incidence of cancer and non-neoplastic diseases is uncertain owing to the susceptibility of observational studies to confounding and reverse causation. Objective: To conduct a Mendelian randomization study, using germline genetic variants as instrumental variables, to appraise the causal relevance of telomere length for risk of cancer and non-neoplastic diseases. Data Sources: Genomewide association studies (GWAS) published up to January 15, 2015. Study Selection: GWAS of noncommunicable diseases that assayed germline genetic variation and did not select cohort or control participants on the basis of preexisting diseases. Of 163 GWAS of noncommunicable diseases identified, summary data from 103 were available. Data Extraction and Synthesis: Summary association statistics for single nucleotide polymorphisms (SNPs) that are strongly associated with telomere length in the general population. Main Outcomes and Measures: Odds ratios (ORs) and 95% confidence intervals (CIs) for disease per standard deviation (SD) higher telomere length due to germline genetic variation. Results: Summary data were available for 35 cancers and 48 non-neoplastic diseases, corresponding to 420 081 cases (median cases, 2526 per disease) and 1 093 105 controls (median, 6789 per disease). Increased telomere length due to germline genetic variation was generally associated with increased risk for site-specific cancers. The strongest associations (ORs [95% CIs] per 1-SD change in genetically increased telomere length) were observed for glioma, 5.27 (3.15-8.81); serous low-malignant-potential ovarian cancer, 4.35 (2.39-7.94); lung adenocarcinoma, 3.19 (2.40-4.22); neuroblastoma, 2.98 (1.92-4.62); bladder cancer, 2.19 (1.32-3.66); melanoma, 1.87 (1.55-2.26); testicular cancer, 1.76 (1.02-3.04); kidney cancer, 1.55 (1.08-2.23); and endometrial cancer, 1.31 (1.07-1.61). Associations were stronger for rarer cancers and at tissue sites with lower rates of stem cell division. There was generally little evidence of association between genetically increased telomere length and risk of psychiatric, autoimmune, inflammatory, diabetic, and other non-neoplastic diseases, except for coronary heart disease (OR, 0.78 [95% CI, 0.67-0.90]), abdominal aortic aneurysm (OR, 0.63 [95% CI, 0.49-0.81]), celiac disease (OR, 0.42 [95% CI, 0.28-0.61]) and interstitial lung disease (OR, 0.09 [95% CI, 0.05-0.15]). Conclusions and Relevance: It is likely that longer telomeres increase risk for several cancers but reduce risk for some non-neoplastic diseases, including cardiovascular diseases.


Assuntos
Predisposição Genética para Doença/genética , Análise da Randomização Mendeliana/métodos , Neoplasias/genética , Homeostase do Telômero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/genética , Feminino , Estudo de Associação Genômica Ampla , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Medição de Risco/métodos , Telômero/genética
14.
Gut ; 66(6): 1116-1122, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27797938

RESUMO

OBJECTIVE: Telomere shortening occurs as an early event in pancreatic tumorigenesis, and genetic variants at the telomerase reverse transcriptase (TERT) gene region have been associated with pancreatic cancer risk. However, it is unknown whether prediagnostic leucocyte telomere length is associated with subsequent risk of pancreatic cancer. DESIGN: We measured prediagnostic leucocyte telomere length in 386 pancreatic cancer cases and 896 matched controls from five prospective US cohorts. ORs and 95% CIs were calculated using conditional logistic regression. Matching factors included year of birth, cohort (which also matches on sex), smoking status, fasting status and month/year of blood collection. We additionally examined single-nucleotide polymorphisms (SNPs) at the TERT region in relation to pancreatic cancer risk and leucocyte telomere length using logistic and linear regression, respectively. RESULTS: Shorter prediagnostic leucocyte telomere length was associated with higher risk of pancreatic cancer (comparing extreme quintiles of telomere length, OR 1.72; 95% CI 1.07 to 2.78; ptrend=0.048). Results remained unchanged after adjustment for diabetes, body mass index and physical activity. Three SNPs at TERT (linkage disequilibrium r2<0.25) were associated with pancreatic cancer risk, including rs401681 (per minor allele OR 1.33; 95% CI 1.12 to 1.59; p=0.002), rs2736100 (per minor allele OR 1.36; 95% CI 1.13 to 1.63; p=0.001) and rs2736098 (per minor allele OR 0.75; 95% CI 0.63 to 0.90; p=0.002). The minor allele for rs401681 was associated with shorter telomere length (p=0.023). CONCLUSIONS: Prediagnostic leucocyte telomere length and genetic variants at the TERT gene region were associated with risk of pancreatic cancer.


Assuntos
Adenocarcinoma/epidemiologia , Adenocarcinoma/genética , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/genética , Telomerase/genética , Encurtamento do Telômero , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Leucócitos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Estados Unidos/epidemiologia
15.
PLoS Genet ; 12(12): e1006493, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28036406

RESUMO

Recent heritability analyses have indicated that genome-wide association studies (GWAS) have the potential to improve genetic risk prediction for complex diseases based on polygenic risk score (PRS), a simple modelling technique that can be implemented using summary-level data from the discovery samples. We herein propose modifications to improve the performance of PRS. We introduce threshold-dependent winner's-curse adjustments for marginal association coefficients that are used to weight the single-nucleotide polymorphisms (SNPs) in PRS. Further, as a way to incorporate external functional/annotation knowledge that could identify subsets of SNPs highly enriched for associations, we propose variable thresholds for SNPs selection. We applied our methods to GWAS summary-level data of 14 complex diseases. Across all diseases, a simple winner's curse correction uniformly led to enhancement of performance of the models, whereas incorporation of functional SNPs was beneficial only for selected diseases. Compared to the standard PRS algorithm, the proposed methods in combination led to notable gain in efficiency (25-50% increase in the prediction R2) for 5 of 14 diseases. As an example, for GWAS of type 2 diabetes, winner's curse correction improved prediction R2 from 2.29% based on the standard PRS to 3.10% (P = 0.0017) and incorporating functional annotation data further improved R2 to 3.53% (P = 2×10-5). Our simulation studies illustrate why differential treatment of certain categories of functional SNPs, even when shown to be highly enriched for GWAS-heritability, does not lead to proportionate improvement in genetic risk-prediction because of non-uniform linkage disequilibrium structure.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Modelos Genéticos , Herança Multifatorial/genética , Algoritmos , Simulação por Computador , Humanos , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Fatores de Risco
16.
Cancer Res ; 76(24): 7160-7167, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27780823

RESUMO

Leptin is an adipokine involved in regulating energy balance, which has been identified as a potential biologic link in the development of obesity-associated cancers, such as pancreatic cancer. In this prospective, nested case-control study of 470 cases and 1,094 controls from five U.S. cohorts, we used conditional logistic regression to evaluate pancreatic cancer risk by prediagnostic plasma leptin, adjusting for race/ethnicity, diabetes, body mass index, physical activity, plasma C-peptide, adiponectin, and 25-hydroxyvitamin D. Because of known differences in leptin levels by gender, analyses were conducted separately for men and women. We also evaluated associations between 32 tagging SNPs in the leptin receptor (LEPR) gene and pancreatic cancer risk. Leptin levels were higher in female versus male control participants (median, 20.8 vs. 6.7 ng/mL; P < 0.0001). Among men, plasma leptin was positively associated with pancreatic cancer risk and those in the top quintile had a multivariable-adjusted OR of 3.02 [95% confidence interval (CI), 1.27-7.16; Ptrend = 0.02] compared with men in the bottom quintile. Among women, circulating leptin was not associated with pancreatic cancer risk (Ptrend = 0.21). Results were similar across cohorts (Pheterogeneity = 0.88 for two male cohorts and 0.35 for three female cohorts). In genetic analyses, rs10493380 in LEPR was associated with increased pancreatic cancer risk among women, with an OR per minor allele of 1.54 (95% CI, 1.18-2.02; multiple hypothesis-corrected P = 0.03). No SNPs were significantly associated with risk in men. In conclusion, higher prediagnostic levels of plasma leptin were associated with an elevated risk of pancreatic cancer among men, but not among women. Cancer Res; 76(24); 7160-7. ©2016 AACR.


Assuntos
Adenocarcinoma/genética , Biomarcadores Tumorais/genética , Leptina/genética , Neoplasias Pancreáticas/genética , Polimorfismo de Nucleotídeo Único , Receptores para Leptina/genética , Adenocarcinoma/sangue , Biomarcadores Tumorais/sangue , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/sangue , Receptores para Leptina/sangue , Fatores de Risco , Caracteres Sexuais
17.
Nat Commun ; 7: 11843, 2016 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-27291797

RESUMO

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.


Assuntos
Envelhecimento/genética , Cromossomos Humanos X/genética , Mosaicismo , Inativação do Cromossomo X/genética , Metilação de DNA/genética , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
18.
Cancer Epidemiol Biomarkers Prev ; 25(7): 1185-91, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27197284

RESUMO

Individuals from pancreatic cancer families are at increased risk, not only of pancreatic cancer, but also of melanoma, breast, ovarian, and colon cancers. While some of the increased risk may be due to mutations in high-penetrance genes (i.e., BRCA2, PALB2, ATM, p16/CDKN2A or DNA mismatch repair genes), common genetic variants may also be involved. In a high-risk population of cases with either a family history of pancreatic cancer or early-onset pancreatic cancer (diagnosis before the age of 50 years), we examined the role of genetic variants previously associated with risk of pancreatic, breast, ovarian, or prostate cancer. We genotyped 985 cases (79 early-onset cases, 906 cases with a family history of pancreatic cancer) and 877 controls for 215,389 SNPs using the iSelect Collaborative Oncological Gene-Environment Study (iCOGS) array with custom content. Logistic regression was performed using a log-linear additive model. We replicated several previously reported pancreatic cancer susceptibility loci, including recently identified variants on 2p13.3 and 7p13 (2p13.3, rs1486134: OR = 1.36; 95% CI, 1.13-1.63; P = 9.29 × 10(-4); 7p13, rs17688601: OR = 0.76; 95% CI, 0.63-0.93; P = 6.59 × 10(-3)). For the replicated loci, the magnitude of association observed in these high-risk patients was similar to that observed in studies of unselected patients. In addition to the established pancreatic cancer loci, we also found suggestive evidence of association (P < 5 × 10(-5)) to pancreatic cancer for SNPs at HDAC9 (7p21.1) and COL6A2 (21q22.3). Even in high-risk populations, common variants influence pancreatic cancer susceptibility. Cancer Epidemiol Biomarkers Prev; 25(7); 1185-91. ©2016 AACR.


Assuntos
Carcinoma/genética , Predisposição Genética para Doença , Neoplasias Pancreáticas/genética , Adulto , Carcinoma/epidemiologia , Estudos de Casos e Controles , Reparo de Erro de Pareamento de DNA , Genes BRCA2 , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Nucleares/genética , Neoplasias Pancreáticas/epidemiologia , Polimorfismo de Nucleotídeo Único , Fatores de Risco
19.
Int J Biol Sci ; 12(3): 314-25, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26929738

RESUMO

Although relatively rare, pancreatic tumors are highly lethal [1]. In the United States, an estimated 48,960 individuals will be diagnosed with pancreatic cancer and 40,560 will die from this disease in 2015 [1]. Globally, 337,872 new pancreatic cancer cases and 330,391 deaths were estimated in 2012 [2]. In contrast to most other cancers, mortality rates for pancreatic cancer are not improving; in the US, it is predicted to become the second leading cause of cancer related deaths by 2030 [3, 4]. The vast majority of tumors arise in the exocrine pancreas, with pancreatic ductal adenocarcinoma (PDAC) accounting for approximately 95% of tumors. Tumors arising in the endocrine pancreas (pancreatic neuroendocrine tumors) represent less than 5% of all pancreatic tumors [5]. Smoking, type 2 diabetes mellitus (T2D), obesity and pancreatitis are the most consistent epidemiological risk factors for pancreatic cancer [5]. Family history is also a risk factor for developing pancreatic cancer with odds ratios (OR) ranging from 1.7-2.3 for first-degree relatives in most studies, indicating that shared genetic factors may play a role in the etiology of this disease [6-9]. This review summarizes the current knowledge of germline pancreatic cancer risk variants with a special emphasis on common susceptibility alleles identified through Genome Wide Association Studies (GWAS).


Assuntos
Neoplasias Pancreáticas/genética , Animais , Carcinoma Ductal Pancreático/genética , Diabetes Mellitus Tipo 2/genética , Estudo de Associação Genômica Ampla , Humanos , Fatores de Risco
20.
J Natl Cancer Inst ; 108(6): djv409, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26755275

RESUMO

BACKGROUND: Pancreatic tumors cause changes in whole-body metabolism, but whether prediagnostic circulating metabolites predict survival is unknown. METHODS: We measured 82 metabolites by liquid chromatography-mass spectrometry in prediagnostic plasma from 484 pancreatic cancer case patients enrolled in four prospective cohort studies. Association of metabolites with survival was evaluated using Cox proportional hazards models adjusted for age, cohort, race/ethnicity, cancer stage, fasting time, and diagnosis year. After multiple-hypothesis testing correction, a P value of .0006 or less (.05/82) was considered statistically significant. Based on the results, we evaluated 33 tagging single-nucleotide polymorphisms (SNPs) in the ACO1 gene, requiring a P value of less than .002 (.05/33) for statistical significance. All statistical tests were two-sided. RESULTS: Two metabolites in the tricarboxylic acid (TCA) cycle--isocitrate and aconitate--were statistically significantly associated with survival. Participants in the highest vs lowest quintile had hazard ratios (HRs) for death of 1.89 (95% confidence interval [CI] = 1.06 to 3.35, Ptrend < .001) for isocitrate and 2.54 (95% CI = 1.42 to 4.54, Ptrend < .001) for aconitate. Isocitrate is interconverted with citrate via the intermediate aconitate in a reaction catalyzed by the enzyme aconitase 1 (ACO1). Therefore, we investigated the citrate to aconitate plus isocitrate ratio and SNPs in the ACO1 gene. The ratio was strongly associated with survival (P trend < .001) as was the SNP rs7874815 in the ACO1 gene (hazard ratio for death per minor allele = 1.37, 95% CI = 1.16 to 1.61, P < .001). Patients had an approximately three-fold hazard for death when possessing one or more minor alleles at rs7874851 and high aconitate or isocitrate. CONCLUSIONS: Prediagnostic circulating levels of TCA cycle intermediates and inherited ACO1 genotypes were associated with survival among patients with pancreatic cancer.


Assuntos
Biomarcadores Tumorais/sangue , Proteína 1 Reguladora do Ferro/sangue , Proteína 1 Reguladora do Ferro/genética , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/mortalidade , Polimorfismo de Nucleotídeo Único , Ácidos Tricarboxílicos/sangue , Ácido Aconítico/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Genótipo , Humanos , Isocitratos/sangue , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros , Razão de Chances , Neoplasias Pancreáticas/diagnóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estados Unidos/epidemiologia , Saúde da Mulher
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