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1.
Am J Hum Genet ; 108(10): 1852-1865, 2021 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-34559995

RESUMEN

Genome-wide association studies (GWASs) have discovered 20 risk loci in the human genome where germline variants associate with risk of pancreatic ductal adenocarcinoma (PDAC) in populations of European ancestry. Here, we fine-mapped one such locus on chr16q23.1 (rs72802365, p = 2.51 × 10-17, OR = 1.36, 95% CI = 1.31-1.40) and identified colocalization (PP = 0.87) with aberrant exon 5-7 CTRB2 splicing in pancreatic tissues (pGTEx = 1.40 × 10-69, ßGTEx = 1.99; pLTG = 1.02 × 10-30, ßLTG = 1.99). Imputation of a 584 bp structural variant overlapping exon 6 of CTRB2 into the GWAS datasets resulted in a highly significant association with pancreatic cancer risk (p = 2.83 × 10-16, OR = 1.36, 95% CI = 1.31-1.42), indicating that it may underlie this signal. Exon skipping attributable to the deletion (risk) allele introduces a premature stop codon in exon 7 of CTRB2, yielding a truncated chymotrypsinogen B2 protein that lacks chymotrypsin activity, is poorly secreted, and accumulates intracellularly in the endoplasmic reticulum (ER). We propose that intracellular accumulation of a nonfunctional chymotrypsinogen B2 protein leads to ER stress and pancreatic inflammation, which may explain the increased pancreatic cancer risk in carriers of CTRB2 exon 6 deletion alleles.


Asunto(s)
Quimotripsina/genética , Neoplasias Pancreáticas/patología , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Eliminación de Secuencia , Estudios de Casos y Controles , Quimotripsina/antagonistas & inhibidores , Quimotripsina/metabolismo , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Neoplasias Pancreáticas/etiología , Neoplasias Pancreáticas/metabolismo
2.
PLoS Comput Biol ; 17(11): e1009563, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34793442

RESUMEN

Expression QTL (eQTL) analyses have suggested many genes mediating genome-wide association study (GWAS) signals but most GWAS signals still lack compelling explanatory genes. We have leveraged an adipose-specific gene regulatory network to infer expression regulator activities and phenotypic master regulators (MRs), which were used to detect activity QTLs (aQTLs) at cardiometabolic trait GWAS loci. Regulator activities were inferred with the VIPER algorithm that integrates enrichment of expected expression changes among a regulator's target genes with confidence in their regulator-target network interactions and target overlap between different regulators (i.e., pleiotropy). Phenotypic MRs were identified as those regulators whose activities were most important in predicting their respective phenotypes using random forest modeling. While eQTLs were typically more significant than aQTLs in cis, the opposite was true among candidate MRs in trans. Several GWAS loci colocalized with MR trans-eQTLs/aQTLs in the absence of colocalized cis-QTLs. Intriguingly, at the 1p36.1 BMI GWAS locus the EPHB2 cis-aQTL was stronger than its cis-eQTL and colocalized with the GWAS signal and 35 BMI MR trans-aQTLs, suggesting the GWAS signal may be mediated by effects on EPHB2 activity and its downstream effects on a network of BMI MRs. These MR and aQTL analyses represent systems genetic methods that may be broadly applied to supplement standard eQTL analyses for suggesting molecular effects mediating GWAS signals.


Asunto(s)
Redes Reguladoras de Genes , Miocardio/metabolismo , Estudio de Asociación del Genoma Completo/métodos , Humanos , Fenotipo , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Receptor EphB2/genética , Grasa Subcutánea/metabolismo , Transcriptoma
3.
Gut ; 67(3): 521-533, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28634199

RESUMEN

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.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/genética , Expresión Génica , Páncreas , Neoplasias Pancreáticas/genética , Sitios de Carácter Cuantitativo , ARN Neoplásico/análisis , Transcriptoma , Alelos , Cromosomas Humanos Par 9 , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Degradación de ARNm Mediada por Codón sin Sentido , Polimorfismo de Nucleótido Simple , Secuencias Reguladoras de Ácidos Nucleicos , Análisis de Secuencia de ARN
4.
Hum Mol Genet ; 25(21): 4726-4738, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28172817

RESUMEN

Genome-wide association studies (GWAS) have identified multiple common susceptibility loci for pancreatic cancer. Here we report fine-mapping and functional analysis of one such locus residing in a 610 kb gene desert on chr13q22.1 (marked by rs9543325). The closest candidate genes, KLF5, KLF12, PIBF1, DIS3 and BORA, range in distance from 265-586 kb. Sequencing three sub-regions containing the top ranked SNPs by imputation P-value revealed a 30 bp insertion/deletion (indel) variant that was significantly associated with pancreatic cancer risk (rs386772267, P = 2.30 × 10-11, OR = 1.22, 95% CI 1.15-1.28) and highly correlated to rs9543325 (r2 = 0.97 in the 1000 Genomes EUR population). This indel was the most significant cis-eQTL variant in a set of 222 histologically normal pancreatic tissue samples (ß = 0.26, P = 0.004), with the insertion (risk-increasing) allele associated with reduced DIS3 expression. DIS3 encodes a catalytic subunit of the nuclear RNA exosome complex that mediates RNA processing and decay, and is mutated in several cancers. Chromosome conformation capture revealed a long range (570 kb) physical interaction between a sub-region of the risk locus, containing rs386772267, and a region ∼6 kb upstream of DIS3 Finally, repressor regulatory activity and allele-specific protein binding by transcription factors of the TCF/LEF family were observed for the risk-increasing allele of rs386772267, indicating that expression regulation at this risk locus may be influenced by the Wnt signaling pathway. In conclusion, we have identified a putative functional indel variant at chr13q22.1 that associates with decreased DIS3 expression in carriers of pancreatic cancer risk-increasing alleles, and could therefore affect nuclear RNA processing and/or decay.


Asunto(s)
Cromosomas Humanos Par 13 , Complejo Multienzimático de Ribonucleasas del Exosoma/genética , Neoplasias Pancreáticas/genética , Alelos , Línea Celular Tumoral , Cromatina/genética , Cromatina/metabolismo , Mapeo Cromosómico/métodos , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Sitios Genéticos , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Mutación INDEL , Neoplasias Pancreáticas/enzimología , Neoplasias Pancreáticas/metabolismo , Análisis de Secuencia de ADN , Factores de Transcripción/genética
5.
Carcinogenesis ; 35(12): 2670-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25233928

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is driven by the accumulation of somatic mutations, epigenetic modifications and changes in the micro-environment. New approaches to investigating disruptions of gene expression networks promise to uncover key regulators and pathways in carcinogenesis. We performed messenger RNA-sequencing in pancreatic normal (n = 10) and tumor (n = 8) derived tissue samples, as well as in pancreatic cancer cell lines (n = 9), to determine differential gene expression (DE) patterns. Sub-network enrichment analyses identified HNF1A as the regulator of the most significantly and consistently dysregulated expression sub-network in pancreatic tumor tissues and cells (median P = 7.56×10(-7), median rank = 1, range = 1-25). To explore the effects of HNF1A expression in pancreatic tumor-derived cells, we generated stable HNF1A-inducible clones in two pancreatic cancer cell lines (PANC-1 and MIA PaCa-2) and observed growth inhibition (5.3-fold, P = 4.5×10(-5) for MIA PaCa-2 clones; 7.2-fold, P = 2.2×10(-5) for PANC-1 clones), and a G0/G1 cell cycle arrest and apoptosis upon induction. These effects correlated with HNF1A-induced down-regulation of 51 of 84 cell cycle genes (e.g. E2F1, CDK2, CDK4, MCM2/3/4/5, SKP2 and CCND1), decreased expression of anti-apoptotic genes (e.g. BIRC2/5/6 and AKT) and increased expression of pro-apoptotic genes (e.g. CASP4/9/10 and APAF1). In light of the established role of HNF1A in the regulation of pancreatic development and homeostasis, our data suggest that it also functions as an important tumor suppressor in the pancreas.


Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma Ductal Pancreático/genética , Perfilación de la Expresión Génica , Genes Supresores de Tumor , Factor Nuclear 1-alfa del Hepatocito/genética , Neoplasias Pancreáticas/genética , Apoptosis , Biomarcadores de Tumor/metabolismo , Western Blotting , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Ciclo Celular , Proliferación Celular , Células Cultivadas , Citometría de Flujo , Redes Reguladoras de Genes , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Humanos , Técnicas para Inmunoenzimas , Páncreas/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
6.
Hum Genet ; 129(6): 675-85, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21318478

RESUMEN

Measurements of serum prostate-specific antigen (PSA) protein levels form the basis for a widely used test to screen men for prostate cancer. Germline variants in the gene that encodes the PSA protein (KLK3) have been shown to be associated with both serum PSA levels and prostate cancer. Based on a resequencing analysis of a 56 kb region on chromosome 19q13.33, centered on the KLK3 gene, we fine mapped this locus by genotyping tag SNPs in 3,522 prostate cancer cases and 3,338 controls from five case-control studies. We did not observe a strong association with the KLK3 variant, reported in previous studies to confer risk for prostate cancer (rs2735839; P = 0.20) but did observe three highly correlated SNPs (rs17632542, rs62113212 and rs62113214) associated with prostate cancer [P = 3.41 × 10(-4), per-allele trend odds ratio (OR) = 0.77, 95% CI = 0.67-0.89]. The signal was apparent only for nonaggressive prostate cancer cases with Gleason score <7 and disease stage 8 or stage ≥III (P = 0.31, per-allele trend OR = 1.12, 95% CI = 0.90-1.40). One of the three highly correlated SNPs, rs17632542, introduces a non-synonymous amino acid change in the KLK3 protein with a predicted benign or neutral functional impact. Baseline PSA levels were 43.7% higher in control subjects with no minor alleles (1.61 ng/ml, 95% CI = 1.49-1.72) than in those with one or more minor alleles at any one of the three SNPs (1.12 ng/ml, 95% CI = 0.96-1.28) (P = 9.70 × 10(-5)). Together our results suggest that germline KLK3 variants could influence the diagnosis of nonaggressive prostate cancer by influencing the likelihood of biopsy.


Asunto(s)
Cromosomas Humanos Par 19 , Predisposición Genética a la Enfermedad , Calicreínas/genética , Antígeno Prostático Específico/biosíntesis , Neoplasias de la Próstata/genética , Estudios de Casos y Controles , Mapeo Cromosómico , Mutación de Línea Germinal , Humanos , Masculino , Polimorfismo de Nucleótido Simple
7.
Hum Genet ; 127(1): 91-9, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19823874

RESUMEN

Single nucleotide polymorphisms (SNPs) in the KLK3 gene on chromosome 19q13.33 are associated with serum prostate-specific antigen (PSA) levels. Recent genome wide association studies of prostate cancer have yielded conflicting results for association of the same SNPs with prostate cancer risk. Since the KLK3 gene encodes the PSA protein that forms the basis for a widely used screening test for prostate cancer, it is critical to fully characterize genetic variation in this region and assess its relationship with the risk of prostate cancer. We have conducted a next-generation sequence analysis in 78 individuals of European ancestry to characterize common (minor allele frequency, MAF >1%) genetic variation in a 56 kb region on chromosome 19q13.33 centered on the KLK3 gene (chr19:56,019,829-56,076,043 bps). We identified 555 polymorphic loci in the process including 116 novel SNPs and 182 novel insertion/deletion polymorphisms (indels). Based on tagging analysis, 144 loci are necessary to tag the region at an r (2) threshold of 0.8 and MAF of 1% or higher, while 86 loci are required to tag the region at an r (2) threshold of 0.8 and MAF >5%. Our sequence data augments coverage by 35 and 78% as compared to variants in dbSNP and HapMap, respectively. We observed six non-synonymous amino acid or frame shift changes in the KLK3 gene and three changes in each of the neighboring genes, KLK15 and KLK2. Our study has generated a detailed map of common genetic variation in the genomic region surrounding the KLK3 gene, which should be useful for fine-mapping the association signal as well as determining the contribution of this locus to prostate cancer risk and/or regulation of PSA expression.


Asunto(s)
Cromosomas Humanos Par 19/genética , Calicreínas/genética , Polimorfismo de Nucleótido Simple , Antígeno Prostático Específico/genética , Calicreínas de Tejido/genética , Femenino , Frecuencia de los Genes , Haplotipos , Humanos , Mutación INDEL , Desequilibrio de Ligamiento , Masculino , Mutación , Neoplasias de la Próstata/etnología , Neoplasias de la Próstata/genética , Análisis de Secuencia de ADN , Población Blanca/genética
8.
J Natl Cancer Inst ; 112(10): 1003-1012, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31917448

RESUMEN

BACKGROUND: Although 20 pancreatic cancer susceptibility loci have been identified through genome-wide association studies in individuals of European ancestry, much of its heritability remains unexplained and the genes responsible largely unknown. METHODS: To discover novel pancreatic cancer risk loci and possible causal genes, we performed a pancreatic cancer transcriptome-wide association study in Europeans using three approaches: FUSION, MetaXcan, and Summary-MulTiXcan. We integrated genome-wide association studies summary statistics from 9040 pancreatic cancer cases and 12 496 controls, with gene expression prediction models built using transcriptome data from histologically normal pancreatic tissue samples (NCI Laboratory of Translational Genomics [n = 95] and Genotype-Tissue Expression v7 [n = 174] datasets) and data from 48 different tissues (Genotype-Tissue Expression v7, n = 74-421 samples). RESULTS: We identified 25 genes whose genetically predicted expression was statistically significantly associated with pancreatic cancer risk (false discovery rate < .05), including 14 candidate genes at 11 novel loci (1p36.12: CELA3B; 9q31.1: SMC2, SMC2-AS1; 10q23.31: RP11-80H5.9; 12q13.13: SMUG1; 14q32.33: BTBD6; 15q23: HEXA; 15q26.1: RCCD1; 17q12: PNMT, CDK12, PGAP3; 17q22: SUPT4H1; 18q11.22: RP11-888D10.3; and 19p13.11: PGPEP1) and 11 at six known risk loci (5p15.33: TERT, CLPTM1L, ZDHHC11B; 7p14.1: INHBA; 9q34.2: ABO; 13q12.2: PDX1; 13q22.1: KLF5; and 16q23.1: WDR59, CFDP1, BCAR1, TMEM170A). The association for 12 of these genes (CELA3B, SMC2, and PNMT at novel risk loci and TERT, CLPTM1L, INHBA, ABO, PDX1, KLF5, WDR59, CFDP1, and BCAR1 at known loci) remained statistically significant after Bonferroni correction. CONCLUSIONS: By integrating gene expression and genotype data, we identified novel pancreatic cancer risk loci and candidate functional genes that warrant further investigation.


Asunto(s)
Neoplasias Pancreáticas/genética , Bases de Datos Genéticas , Expresión Génica , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Transcriptoma
9.
Pancreas ; 48(7): 894-903, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31268978

RESUMEN

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.


Asunto(s)
Carcinogénesis/genética , Carcinoma in Situ/genética , Gastrinas/genética , Mutación , Páncreas/metabolismo , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Animales , Carcinogénesis/metabolismo , Carcinoma in Situ/metabolismo , Carcinoma in Situ/patología , Línea Celular Tumoral , Proliferación Celular/genética , Gastrinas/metabolismo , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones Noqueados , Ratones Transgénicos , MicroARNs/genética , Páncreas/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas p21(ras)/metabolismo
10.
J Natl Cancer Inst ; 111(6): 557-567, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30541042

RESUMEN

BACKGROUND: Genome-wide association studies (GWAS) identify associations of individual single-nucleotide polymorphisms (SNPs) with cancer risk but usually only explain a fraction of the inherited variability. Pathway analysis of genetic variants is a powerful tool to identify networks of susceptibility genes. METHODS: We conducted a large agnostic pathway-based meta-analysis of GWAS data using the summary-based adaptive rank truncated product method to identify gene sets and pathways associated with pancreatic ductal adenocarcinoma (PDAC) in 9040 cases and 12 496 controls. We performed expression quantitative trait loci (eQTL) analysis and functional annotation of the top SNPs in genes contributing to the top associated pathways and gene sets. All statistical tests were two-sided. RESULTS: We identified 14 pathways and gene sets associated with PDAC at a false discovery rate of less than 0.05. After Bonferroni correction (P ≤ 1.3 × 10-5), the strongest associations were detected in five pathways and gene sets, including maturity-onset diabetes of the young, regulation of beta-cell development, role of epidermal growth factor (EGF) receptor transactivation by G protein-coupled receptors in cardiac hypertrophy pathways, and the Nikolsky breast cancer chr17q11-q21 amplicon and Pujana ATM Pearson correlation coefficient (PCC) network gene sets. We identified and validated rs876493 and three correlating SNPs (PGAP3) and rs3124737 (CASP7) from the Pujana ATM PCC gene set as eQTLs in two normal derived pancreas tissue datasets. CONCLUSION: Our agnostic pathway and gene set analysis integrated with functional annotation and eQTL analysis provides insight into genes and pathways that may be biologically relevant for risk of PDAC, including those not previously identified.


Asunto(s)
Carcinoma Ductal Pancreático/genética , Estudio de Asociación del Genoma Completo/métodos , Neoplasias Pancreáticas/genética , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Humanos , Modelos Estadísticos , Polimorfismo de Nucleótido Simple
11.
Mol Cell Biol ; 25(1): 147-61, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15601838

RESUMEN

A continuous stream of activating and repressing signals is processed by the transcription complex paused at the promoter of the c-myc proto-oncogene. The general transcription factor IIH (TFIIH) is held at promoters prior to promoter escape and so is well situated to channel the input of activators and repressors to modulate c-myc expression. We have compared cells expressing only a mutated p89 (xeroderma pigmentosum complementation group B [XPB]), the largest TFIIH subunit, with the same cells functionally complemented with the wild-type protein (XPB/wt-p89). Here, we show structural, compositional, and functional differences in transcription complexes between XPB and XPB/wt-89 cells at the native c-myc promoter. Remarkably, although the mean levels of c-Myc are only modestly elevated in XPB compared to those in XPB/wt-p89 cells, the range of expression and the cell-to-cell variation of c-Myc are markedly increased. Our modeling indicates that the data can be explained if TFIIH integrates inputs from multiple signals, regulating transcription at multiple kinetically equivalent steps between initiation and promoter escape. This helps to suppress the intrinsic noise of transcription and to ensure the steady transcriptional output of c-myc necessary for cellular homeostasis.


Asunto(s)
Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción TFII/fisiología , Western Blotting , Ciclo Celular , Supervivencia Celular , Inmunoprecipitación de Cromatina , ADN Helicasas , ADN Complementario/metabolismo , Proteínas de Unión al ADN/genética , Fibroblastos/metabolismo , Citometría de Flujo , Prueba de Complementación Genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Cinética , Microscopía Fluorescente , Modelos Biológicos , Modelos Genéticos , Mutación , Plásmidos/metabolismo , Permanganato de Potasio/farmacología , Proto-Oncogenes Mas , ARN Mensajero/metabolismo , Ribonucleasas/metabolismo , Factor de Transcripción TFIIH , Transfección , Rayos Ultravioleta
13.
Nat Commun ; 8: 15034, 2017 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-28447668

RESUMEN

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.


Asunto(s)
Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/genética , Melanoma/genética , Neoplasias Pancreáticas/genética , Neoplasias Cutáneas/genética , Telomerasa/genética , Neoplasias Testiculares/genética , Factores de Transcripción/genética , Alelos , Línea Celular Tumoral , Mapeo Cromosómico , Cromosomas Humanos Par 5 , Proteínas de Unión al ADN/antagonistas & inhibidores , Proteínas de Unión al ADN/metabolismo , Femenino , Sitios Genéticos , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Histonas/genética , Histonas/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Melanoma/metabolismo , Melanoma/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Polimorfismo de Nucleótido Simple , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Transducción de Señal , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Telomerasa/antagonistas & inhibidores , Telomerasa/metabolismo , Homeostasis del Telómero , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patología , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/metabolismo
14.
Oncotarget ; 7(41): 66328-66343, 2016 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-27579533

RESUMEN

Genome-wide association studies (GWAS) have identified common pancreatic cancer susceptibility variants at 13 chromosomal loci in individuals of European descent. To identify new susceptibility variants, we performed imputation based on 1000 Genomes (1000G) Project data and association analysis using 5,107 case and 8,845 control subjects from 27 cohort and case-control studies that participated in the PanScan I-III GWAS. This analysis, in combination with a two-staged replication in an additional 6,076 case and 7,555 control subjects from the PANcreatic Disease ReseArch (PANDoRA) and Pancreatic Cancer Case-Control (PanC4) Consortia uncovered 3 new pancreatic cancer risk signals marked by single nucleotide polymorphisms (SNPs) rs2816938 at chromosome 1q32.1 (per allele odds ratio (OR) = 1.20, P = 4.88x10 -15), rs10094872 at 8q24.21 (OR = 1.15, P = 3.22x10 -9) and rs35226131 at 5p15.33 (OR = 0.71, P = 1.70x10 -8). These SNPs represent independent risk variants at previously identified pancreatic cancer risk loci on chr1q32.1 ( NR5A2), chr8q24.21 ( MYC) and chr5p15.33 ( CLPTM1L- TERT) as per analyses conditioned on previously reported susceptibility variants. We assessed expression of candidate genes at the three risk loci in histologically normal ( n = 10) and tumor ( n = 8) derived pancreatic tissue samples and observed a marked reduction of NR5A2 expression (chr1q32.1) in the tumors (fold change -7.6, P = 5.7x10 -8). This finding was validated in a second set of paired ( n = 20) histologically normal and tumor derived pancreatic tissue samples (average fold change for three NR5A2 isoforms -31.3 to -95.7, P = 7.5x10 -4-2.0x10 -3). Our study has identified new susceptibility variants independently conferring pancreatic cancer risk that merit functional follow-up to identify target genes and explain the underlying biology.


Asunto(s)
Cromosomas Humanos Par 1/genética , Cromosomas Humanos Par 5/genética , Cromosomas Humanos Par 8/genética , Predisposición Genética a la Enfermedad/genética , Neoplasias Pancreáticas/genética , Conjuntos de Datos como Asunto , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Humanos , Polimorfismo de Nucleótido Simple/genética
15.
BMC Bioinformatics ; 6: 259, 2005 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-16232321

RESUMEN

BACKGROUND: The purpose of this study is to determine whether or not there exists nonrandom grouping of cis-regulatory elements within gene promoters that can be perceived independent of gene expression data and whether or not there is any correlation between this grouping and the biological function of the gene. RESULTS: Using ProSpector, a web-based promoter search and annotation tool, we have applied an unbiased approach to analyze the transcription factor binding site frequencies of 1400 base pair genomic segments positioned at 1200 base pairs upstream and 200 base pairs downstream of the transcriptional start site of 7298 commonly studied human genes. Partitional clustering of the transcription factor binding site composition within these promoter segments reveals a small number of gene groups that are selectively enriched for gene ontology terms consistent with distinct aspects of cellular function. Significance ranking of the class-determining transcription factor binding sites within these clusters show substantial overlap between the gene ontology terms of the transcriptions factors associated with the binding sites and the gene ontology terms of the regulated genes within each group. CONCLUSION: Thus, gene sorting by promoter composition alone produces partitions in which the "regulated" and the "regulators" cosegregate into similar functional classes. These findings demonstrate that the transcription factor binding site composition is non-randomly distributed between gene promoters in a manner that reflects and partially defines general gene class function.


Asunto(s)
Expresión Génica/fisiología , Regiones Promotoras Genéticas/genética , Factores de Transcripción/metabolismo , Sitios de Unión , Fenómenos Fisiológicos Celulares , Humanos , Terminología como Asunto
16.
J Med Chem ; 47(20): 4851-7, 2004 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-15369388

RESUMEN

Reversal of aberrant gene expression that is induced by the proto-oncogene c-myc is likely to be effective for treating a variety of tumors that rely on this pathway for growth. One strategy to down-regulate the c-myc pathway is to target transcription factors that regulate its own expression. A host of proteins act in coordination to regulate c-myc expression and any one of them are theoretical targets for small-molecule therapy. Experimentally, it has been shown that the far upstream element (FUSE) binding protein (FBP) is essential for c-myc expression, and reductions in FBP levels both reduce c-myc expression and correlate with slower cell growth. FBP binds to ssDNA by capturing exposed DNA bases in a hydrophobic pocket. This suggests that a small molecule could be designed to occupy this pocket and inhibit FBP function. Using a variety of screening methodologies, we have identified ligands that bind to the DNA binding pockets of the KH domains of FBP. Gel shift analyses using full length FBP and a related transcription factor confirm that a small-molecule lead compound inhibits DNA binding in a specific manner. The benzoylanthranilic acid compounds described here represent leads in the design of FBP inhibitors that can serve as useful tools in the study of c-myc regulation and in the development of therapeutics that target the c-myc pathway.


Asunto(s)
Técnicas Químicas Combinatorias/métodos , Proteínas de Unión al ADN/antagonistas & inhibidores , Genes myc , Espectroscopía de Resonancia Magnética , Regiones Promotoras Genéticas , Sitios de Unión , ADN Helicasas , ADN de Cadena Simple/química , ADN de Cadena Simple/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Diseño de Fármacos , Humanos , Concentración 50 Inhibidora , Ligandos , Modelos Moleculares , Conformación Proteica , Estructura Terciaria de Proteína , Proto-Oncogenes Mas , Proteínas de Unión al ARN , Secuencias Repetitivas de Aminoácido , Relación Estructura-Actividad
17.
Cancer Res ; 74(10): 2785-95, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24648346

RESUMEN

Genome-wide association studies (GWAS) of 10 different cancers have identified pleiotropic cancer predisposition loci across a region of chromosome 5p15.33 that includes the TERT and CLPTM1L genes. Of these, susceptibility alleles for pancreatic cancer have mapped to the CLPTM1L gene, thus prompting an investigation of the function of CLPTM1L in the pancreas. Immunofluorescence analysis indicated that CLPTM1L localized to the endoplasmic reticulum where it is likely embedded in the membrane, in accord with multiple predicted transmembrane domains. Overexpression of CLPTM1L enhanced growth of pancreatic cancer cells in vitro (1.3-1.5-fold; PDAY7 < 0.003) and in vivo (3.46-fold; PDAY68 = 0.039), suggesting a role in tumor growth; this effect was abrogated by deletion of two hydrophilic domains. Affinity purification followed by mass spectrometry identified an interaction between CLPTM1L and non-muscle myosin II (NMM-II), a protein involved in maintaining cell shape, migration, and cytokinesis. The two proteins colocalized in the cytoplasm and, after treatment with a DNA-damaging agent, at the centrosomes. Overexpression of CLPTM1L and depletion of NMM-II induced aneuploidy, indicating that CLPTM1L may interfere with normal NMM-II function in regulating cytokinesis. Immunohistochemical analysis revealed enhanced staining of CLPTM1L in human pancreatic ductal adenocarcinoma (n = 378) as compared with normal pancreatic tissue samples (n = 17; P = 1.7 × 10(-4)). Our results suggest that CLPTM1L functions as a growth-promoting gene in the pancreas and that overexpression may lead to an abrogation of normal cytokinesis, indicating that it should be considered as a plausible candidate gene that could explain the effect of pancreatic cancer susceptibility alleles on chr5p15.33.


Asunto(s)
Carcinoma Ductal Pancreático/patología , Proteínas de la Membrana/biosíntesis , Proteínas de Neoplasias/biosíntesis , Neoplasias Pancreáticas/patología , Aneuploidia , Animales , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Procesos de Crecimiento Celular/fisiología , Línea Celular Tumoral , Femenino , Células HEK293 , Xenoinjertos , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Desnudos , Miosina Tipo II/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Fracciones Subcelulares/metabolismo
18.
BMC Med Genomics ; 6: 33, 2013 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-24053169

RESUMEN

BACKGROUND: Pancreatic cancer is a highly lethal cancer with limited diagnostic and therapeutic modalities. METHODS: To begin to explore the genomic landscape of pancreatic cancer, we used massively parallel sequencing to catalog and compare transcribed regions and potential regulatory elements in two human cell lines derived from normal and cancerous pancreas. RESULTS: By RNA-sequencing, we identified 2,146 differentially expressed genes in these cell lines that were enriched in cancer related pathways and biological processes that include cell adhesion, growth factor and receptor activity, signaling, transcription and differentiation. Our high throughput Chromatin immunoprecipitation (ChIP) sequence analysis furthermore identified over 100,000 regions enriched in epigenetic marks, showing either positive (H3K4me1, H3K4me3, RNA Pol II) or negative (H3K27me3) correlation with gene expression. Notably, an overall enrichment of RNA Pol II binding and depletion of H3K27me3 binding were seen in the cancer derived cell line as compared to the normal derived cell line. By selecting genes for further assessment based on this difference, we confirmed enhanced expression of aldehyde dehydrogenase 1A3 (ALDH1A3) in two larger sets of pancreatic cancer cell lines and in tumor tissues as compared to normal derived tissues. CONCLUSIONS: As aldehyde dehydrogenase (ALDH) activity is a key feature of cancer stem cells, our results indicate that a member of the ALDH superfamily, ALDH1A3, may be upregulated in pancreatic cancer, where it could mark pancreatic cancer stem cells.


Asunto(s)
Aldehído Oxidorreductasas/genética , Epigenómica , Perfilación de la Expresión Génica , Neoplasias Pancreáticas/enzimología , Neoplasias Pancreáticas/genética , Línea Celular Tumoral , Humanos , MicroARNs/genética , Neoplasias Pancreáticas/patología , ARN Mensajero/genética , Análisis de Secuencia de ARN
19.
Gerontologist ; 49(1): 103-16, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19363008

RESUMEN

PURPOSE: The aim of this study was to translate the evidence-based Resources for Enhancing Alzheimer's Caregiver Health (REACH) II intervention for use in 4 Area Agencies on Aging (AAAs). A secondary aim was to examine possible moderators of treatment outcome. DESIGN AND METHODS: We used a quasi-experimental pre-post treatment design with no control group. A partnership was formed between the Alabama Department of Senior Services and the University of Alabama. The partnership trimmed the REACH II intervention used in the clinical trial for feasible use in a social service agency. The condensed REACH intervention, termed REACH OUT, was delivered to 272 dementia caregivers during 4 home visits and 3 phone calls for a period of 4 months. The assessment examined pre-post treatment effects on a number of outcomes, including care recipient risk, mood, memory, and behavior problems; caregiver stress and emotional well-being; caregiver health; and program satisfaction. All aspects of the program except for training, periodic consultation, and data analysis were controlled by the AAA staff. RESULTS: Analyses were conducted on the 236 dyads that completed at least 3 of the 4 planned sessions. Significant positive pre-post effects were found on caregiver subjective burden, social support, caregiver frustration, depression, caregiver health, care recipient behavior problems and mood, and 2 of 4 care recipient risk behaviors. Site of intervention and certain participant characteristics (e.g., caregiver relationship) moderated several pre-post differences. A caregiver survey and interventionist focus group reported high acceptability of the program IMPLICATIONS: This project suggests that the REACH II intervention can be modified for feasible and effective use in AAAs. The next step is to integrate the intervention into usual service delivery to achieve sustainability.


Asunto(s)
Cuidadores , Relaciones Comunidad-Institución , Difusión de Innovaciones , Apoyo Social , Adulto , Anciano , Anciano de 80 o más Años , Alabama , Cuidadores/psicología , Demencia , Práctica Clínica Basada en la Evidencia , Femenino , Grupos Focales , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Universidades , Adulto Joven
20.
J Biol Chem ; 278(42): 41034-46, 2003 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-12896977

RESUMEN

The proximal promoter sequence of the interleukin-2 (IL-2) gene contains a series of composite sites or modules that controls much of its responsiveness to environmental stimuli. The integrated targeting of these modules is therefore a major mode of regulation. This report describes how multiple functional hierarchies, required for the recruitment of the p300 co-activator to the CD28RE/AP1 (TRE) module of the IL-2 promoter, are selectively disrupted in human T-cells by the immunosuppressive and anti-inflammatory actions of the p38 mitogen-activated protein kinase inhibitor (MAPK), SB203580. The molecular hierarchies targeted by SB203580 include the combinatorial interaction of NF-kappaB and CREB at the CD28RE/AP1 element coupled with the subsequent dynamic co-assembly and activation of p300. Several aspects of this targeting are linked to the ability of SB203580 to inhibit p38 MAPK-controlled pathways. Together, these results provide the molecular basis through which the combinatorial structure and context of the composite elements of the IL-2 promoter dictates mitogen responsiveness and drug susceptibility that are quantitatively and qualitatively distinct from the isolated action of single consensus sequences and/or transcriptional motifs.


Asunto(s)
Transcripción Genética , Secuencias de Aminoácidos , Secuencia de Bases , Línea Celular , Núcleo Celular/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Humanos , Imidazoles/farmacología , Interleucina-2/metabolismo , Células Jurkat , Sistema de Señalización de MAP Quinasas , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Modelos Estadísticos , Datos de Secuencia Molecular , Fosforilación , Plásmidos/metabolismo , Pruebas de Precipitina , Regiones Promotoras Genéticas , Piridinas/farmacología , Transducción de Señal , Linfocitos T/metabolismo , Factores de Tiempo , Activación Transcripcional , Transfección , Proteínas Quinasas p38 Activadas por Mitógenos
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