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2.
Sci Rep ; 9(1): 4544, 2019 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-30872698

RESUMEN

Many tumors maintain chromosome-ends through a telomerase-independent, DNA-templated mechanism called alternative lengthening of telomeres (ALT). While ALT occurs in only a subset of tumors, it is strongly associated with mutations in the genes ATRX and DAXX, which encode components of an H3.3 histone chaperone complex. The role of ATRX and DAXX mutations in potentiating the mechanism of ALT remains incompletely understood. Here we characterize an osteosarcoma cell line, G292, with wild-type ATRX but a unique chromosome translocation resulting in loss of DAXX function. While ATRX and DAXX form a complex in G292, this complex fails to localize to nuclear PML bodies. We demonstrate that introduction of wild type DAXX suppresses the ALT phenotype and restores the localization of ATRX/DAXX to PML bodies. Using an inducible system, we show that ALT-associated PML bodies are disrupted rapidly following DAXX induction and that ALT is again restored following withdrawal of DAXX.


Asunto(s)
Neoplasias Óseas/genética , Proteínas Co-Represoras/genética , Chaperonas Moleculares/genética , Mutación , Osteosarcoma/genética , Homeostasis del Telómero , Neoplasias Óseas/patología , Humanos , Osteosarcoma/patología , Fenotipo , Telomerasa/genética , Telomerasa/metabolismo , Células Tumorales Cultivadas
3.
Genome Biol ; 19(1): 123, 2018 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-30143034

RESUMEN

BACKGROUND: Lung cancer is the leading cancer diagnosis worldwide and the number one cause of cancer deaths. Exposure to cigarette smoke, the primary risk factor in lung cancer, reduces epithelial barrier integrity and increases susceptibility to infections. Herein, we hypothesize that somatic mutations together with cigarette smoke generate a dysbiotic microbiota that is associated with lung carcinogenesis. Using lung tissue from 33 controls and 143 cancer cases, we conduct 16S ribosomal RNA (rRNA) bacterial gene sequencing, with RNA-sequencing data from lung cancer cases in The Cancer Genome Atlas serving as the validation cohort. RESULTS: Overall, we demonstrate a lower alpha diversity in normal lung as compared to non-tumor adjacent or tumor tissue. In squamous cell carcinoma specifically, a separate group of taxa are identified, in which Acidovorax is enriched in smokers. Acidovorax temporans is identified within tumor sections by fluorescent in situ hybridization and confirmed by two separate 16S rRNA strategies. Further, these taxa, including Acidovorax, exhibit higher abundance among the subset of squamous cell carcinoma cases with TP53 mutations, an association not seen in adenocarcinomas. CONCLUSIONS: The results of this comprehensive study show both microbiome-gene and microbiome-exposure interactions in squamous cell carcinoma lung cancer tissue. Specifically, tumors harboring TP53 mutations, which can impair epithelial function, have a unique bacterial consortium that is higher in relative abundance in smoking-associated tumors of this type. Given the significant need for clinical diagnostic tools in lung cancer, this study may provide novel biomarkers for early detection.


Asunto(s)
Neoplasias Pulmonares/genética , Neoplasias Pulmonares/microbiología , Microbiota/genética , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Biodiversidad , Comamonadaceae/clasificación , Comamonadaceae/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación/genética , Neoplasias de Células Escamosas/genética , Neoplasias de Células Escamosas/microbiología , Proteobacteria/metabolismo , Reproducibilidad de los Resultados , Fumadores , Proteína p53 Supresora de Tumor/metabolismo
4.
J Thorac Oncol ; 5(9): 1447-53, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20651610

RESUMEN

BACKGROUND: Overexpression of c-kit, a tyrosine kinase receptor protein encoded by the protooncogene kit, has been previously reported in thymic epithelial tumors and in other neoplasms such as gastrointestinal stromal tumors, myeloproliferative disorders, melanoma, and seminoma. Mutations in the kit gene have been related to response to imatinib in gastrointestinal stromal tumor and one case report of thymic carcinoma. We studied expression of c-kit in a large retrospective series of thymic epithelial malignancies and sequenced the whole gene in a subset of patients. METHODS: Thymic epithelial tumors from 120 patients (13 thymic carcinomas and 107 thymomas) were examined. Immunohistochemical staining with an antic-kit polyclonal antibody was performed on a tissue microarray. Mutation analyses of exons 1 to 20 were conducted by direct DNA sequencing of polymerase chain reaction products in eight thymic carcinomas, five thymomas, and one thymic carcinoma cell line. RESULTS: The percentage of c-kit positive cells was significantly higher in thymic carcinoma (46%) than in thymoma (4%). Decreased disease-related survival and progression-free survival were observed in c-kit positive tumors. No mutations were detected. CONCLUSION: c-kit expression is strongly but not exclusively related to thymic carcinoma histotype, and it is of prognostic value. Mutations are very rare.


Asunto(s)
Mutación/genética , Proteínas Proto-Oncogénicas c-kit/genética , Timoma/genética , Neoplasias del Timo/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , ADN de Neoplasias/genética , Exones/genética , Femenino , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Pronóstico , Proteínas Proto-Oncogénicas c-kit/metabolismo , Estudios Retrospectivos , Tasa de Supervivencia , Timoma/metabolismo , Timoma/patología , Neoplasias del Timo/metabolismo , Neoplasias del Timo/patología , Análisis de Matrices Tisulares
5.
Int J Cancer ; 122(1): 177-82, 2008 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-17764108

RESUMEN

High-dose ionizing radiation exposure to the breast and rare autosomal dominant genes have been linked with increased breast cancer risk, but the role of low-to-moderate doses from protracted radiation exposure in breast cancer risk and its potential modification by polymorphisms in DNA repair genes has not been previously investigated among large numbers of radiation-exposed women with detailed exposure data. Using carefully reconstructed estimates of cumulative breast doses from occupational and personal diagnostic ionizing radiation, we investigated the potential modification of radiation-related breast cancer risk by 55 candidate single nucleotide polymorphisms in 17 genes involved in base excision or DNA double-strand break repair among 859 cases and 1083 controls from the United States Radiologic Technologists (USRT) cohort. In multivariable analyses, WRN V114I (rs2230009) significantly modified the association between cumulative occupational breast dose and risk of breast cancer (adjusted for personal diagnostic exposure) (p = 0.04) and BRCA1 D652N (rs4986850), PRKDC IVS15 + 6C > T (rs1231202), PRKDC IVS34 + 39T > C (rs8178097) and PRKDC IVS31 - 634C > A (rs10109984) significantly altered the personal diagnostic radiation exposure-response relationship (adjusted for occupational dose) (p < or = 0.05). None of the remaining 50 SNPs significantly modified breast cancer radiation dose-response relationships. The USRT genetic study provided a unique opportunity to examine the joint effects of common genetic variation and ionizing radiation exposure on breast cancer risk using detailed occupational and personal diagnostic exposure data. The suggestive evidence found for modification of radiation-related breast cancer risk for 5 of the 55 SNPs evaluated requires confirmation in larger studies of women with quantified radiation breast doses in the low-to-moderate range.


Asunto(s)
Neoplasias de la Mama/epidemiología , Enzimas Reparadoras del ADN/genética , Reparación del ADN/genética , Neoplasias Inducidas por Radiación/epidemiología , Exposición Profesional , Polimorfismo de Nucleótido Simple/genética , Tecnología Radiológica , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/etiología , Relación Dosis-Respuesta en la Radiación , Femenino , Genotipo , Humanos , Incidencia , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Radiación Ionizante , Estudios Retrospectivos , Factores de Riesgo , Estados Unidos/epidemiología , Recursos Humanos
6.
BMC Genet ; 8: 68, 2007 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-17916242

RESUMEN

BACKGROUND: We studied linkage disequilibrium (LD) patterns at the BRCA1 locus, a susceptibility gene for breast and ovarian cancer, using a dense set of 114 single nucleotide polymorphisms in 5 population groups. We focused on Ashkenazi Jews in whom there are known founder mutations, to address the question of whether we would have been able to identify the 185delAG mutation in a case-control association study (should one have been done) using anonymous genetic markers. This mutation is present in approximately 1% of the general Ashkenazi population and 4% of Ashkenazi breast cancer cases. We evaluated LD using pairwise and haplotype-based methods, and assessed correlation of SNPs with the founder mutations using Pearson's correlation coefficient. RESULTS: BRCA1 is characterized by very high linkage disequilibrium in all populations spanning several hundred kilobases. Overall, haplotype blocks and pair-wise LD bins were highly correlated, with lower LD in African versus non-African populations. The 185delAG and 5382insC founder mutations occur on the two most common haplotypes among Ashkenazim. Because these mutations are rare, even though they are in strong LD with many other SNPs in the region as measured by D-prime, there were no strong associations when assessed by Pearson's correlation coefficient, r (maximum of 0.04 for the 185delAG). CONCLUSION: Since the required sample size is related to the inverse of r, this suggests that it would have been difficult to map BRCA1 in an Ashkenazi case-unrelated control association study using anonymous markers that were linked to the founder mutations.


Asunto(s)
Efecto Fundador , Genes BRCA1 , Predisposición Genética a la Enfermedad , Judíos/genética , Neoplasias de la Mama/etnología , Neoplasias de la Mama/genética , Estudios de Casos y Controles , Femenino , Genoma Humano , Haplotipos , Humanos , Desequilibrio de Ligamiento , Neoplasias Ováricas/etnología , Neoplasias Ováricas/genética , Polimorfismo de Nucleótido Simple , Eliminación de Secuencia
7.
Cancer Epidemiol Biomarkers Prev ; 16(1): 174-7, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17220349

RESUMEN

Several variants in the TSHR and RET signaling pathways genes have been reported to be related to cancer risk. We hypothesized that polymorphic variants in these genes are associated with the risk of papillary thyroid cancer. A nested case-control study was conducted within the U.S. Radiologic Technologists cohort. Eligible validated papillary thyroid cancer cases (n = 167) and frequency-matched (by sex and birth year) controls (n = 491) donated blood for analysis. There were no statistically significant associations between papillary thyroid cancer and 10 selected polymorphic variants in analyses of men and women combined. A borderline significant increasing risk was found for RET G691S (P(trend) = 0.05) and was especially pronounced among young women. For women under 38 years (the median age at diagnosis), the odds ratios were 2.1 (95% confidence interval, 1.2-3.7) for those heterozygous for the RET G691S polymorphism and 3.7 (95% confidence interval, 1.1-11.8) for those who were homozygous (P(trend) = 0.001). Our data provide limited evidence that TSHR- and RET-related genes are related to papillary thyroid cancer risk.


Asunto(s)
Carcinoma Papilar/genética , Polimorfismo Genético , Proteínas Proto-Oncogénicas c-ret/genética , Receptores de Tirotropina/genética , Neoplasias de la Tiroides/genética , Adulto , Anciano , Carcinoma Papilar/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-ret/sangre , Receptores de Tirotropina/sangre , Neoplasias de la Tiroides/sangre
8.
Hum Mutat ; 27(6): 538-44, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16652348

RESUMEN

Homozygous mutation in the ATM gene causes ataxia telangiectasia and heterozygous mutation carriers may be at increased risk of breast cancer. We studied a total of 22 ATM variants; 18 variants were analyzed in one of two large population-based studies from the U.S. and Poland, and four variants were analyzed in all 2,856 breast cancer cases and 3,344 controls from the two studies. The missense mutation Ser49Cys (c.146C>G, p.S49C), carried by approximately 2% of subjects, was more common in cases than controls in both study populations, combined odds ratio (OR) 1.69 (95% CI, 1.19-2.40; P=0.004). Another missense mutation at approximately 2% frequency, Phe858Leu (c.2572T>C, p.F858L), was associated with a significant increased risk in the U.S. study but not in Poland, and had a combined OR of 1.44 (95% CI, 0.98-2.11; P=0.06). These analyses provide the most convincing evidence thus far that missense mutations in ATM, particularly p.S49C, may be breast cancer susceptibility alleles. Because of their low frequency, even larger sample sizes are required to more firmly establish these associations.


Asunto(s)
Neoplasias de la Mama/genética , Proteínas de Ciclo Celular/genética , Proteínas de Unión al ADN/genética , Mutación Missense , Proteínas Serina-Treonina Quinasas/genética , Proteínas Supresoras de Tumor/genética , Adulto , Anciano , Alelos , Proteínas de la Ataxia Telangiectasia Mutada , Neoplasias de la Mama/epidemiología , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Polonia/epidemiología , Factores de Riesgo , Estados Unidos/epidemiología
10.
Hum Mutat ; 22(2): 121-8, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12872252

RESUMEN

Two potential breast cancer susceptibility genes, encoding the BRCA1-interacting proteins ZNF350 (or ZBRK1) and BRIP1 (or BACH1), have been identified in yeast two-hybrid screens. We sequenced these genes in probands from 21 families with potentially inherited breast/ovarian cancer, all of which were negative for BRCA1/BRCA2 mutations. Families had at least one case of male breast cancer, two cases of ovarian cancer, or three or more cases of breast and ovarian cancer. In addition, 58 early-onset (before age 35) breast cancer cases and 30 reference individuals were analyzed. Of 17 variants detected in ZBRK1, a missense mutation Val524Ile was identified in the proband of one high-risk family, but no other family members were available for testing. Of 25 variants identified in BRIP1, in addition to four common silent or missense mutations, we identified Gln540Leu, a non-conservative amino acid change, in a single familial proband with inflammatory breast cancer, but this mutation was not present in her three relatives with breast cancer. Haplotype analysis suggests that all ZBRK1 SNPs fall within a single block with two SNPs capturing 92% of the haplotype diversity, while the BRIP1 SNPs fall in two blocks, with five SNPs capturing 89% of the haplotype diversity. Based on sequencing of ZBRK1 and BRIP1 in 21 BRCA1/2-negative probands from inherited breast/ovarian cancer families, it appears unlikely that mutations in these genes account for a significant fraction of inherited breast cancer. Further analysis in unselected cases will be required to know whether the identified variants play a role in genetic predisposition to breast cancer in the general population. Hum Mutat 22:121-128, 2003. Published 2003 Wiley-Liss, Inc.


Asunto(s)
Neoplasias de la Mama Masculina/genética , Neoplasias de la Mama/genética , Análisis Mutacional de ADN/métodos , Proteínas de Unión al ADN , Genes BRCA1 , Genes BRCA2 , Neoplasias Ováricas/genética , Proteínas Represoras/genética , Factores de Transcripción/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , ADN de Neoplasias/genética , Familia , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Femenino , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/fisiología , Regulación Neoplásica de la Expresión Génica/genética , Haplotipos/genética , Humanos , Leucina Zippers/genética , Desequilibrio de Ligamiento/genética , Masculino , Mutación Missense/genética , Linaje , Proteínas Represoras/fisiología , Factores de Transcripción/fisiología , Dedos de Zinc/genética
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