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2.
Sci Rep ; 9(1): 4544, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30872698

RESUMO

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.


Assuntos
Neoplasias Ósseas/genética , Proteínas Correpressoras/genética , Chaperonas Moleculares/genética , Mutação , Osteossarcoma/genética , Homeostase do Telômero , Neoplasias Ósseas/patologia , Humanos , Osteossarcoma/patologia , Fenótipo , Telomerase/genética , Telomerase/metabolismo , Células Tumorais Cultivadas
3.
Int J Cancer ; 122(1): 177-82, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17764108

RESUMO

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.


Assuntos
Neoplasias da Mama/epidemiologia , Enzimas Reparadoras do DNA/genética , Reparo do DNA/genética , Neoplasias Induzidas por Radiação/epidemiologia , Exposição Ocupacional , Polimorfismo de Nucleotídeo Único/genética , Tecnologia Radiológica , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/etiologia , Relação Dose-Resposta à Radiação , Feminino , Genótipo , Humanos , Incidência , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/etiologia , Radiação Ionizante , Estudos Retrospectivos , Fatores de Risco , Estados Unidos/epidemiologia , Recursos Humanos
4.
Genome Biol ; 19(1): 123, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-30143034

RESUMO

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.


Assuntos
Neoplasias Pulmonares/genética , Neoplasias Pulmonares/microbiologia , Microbiota/genética , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Biodiversidade , Comamonadaceae/classificação , Comamonadaceae/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Neoplasias de Células Escamosas/genética , Neoplasias de Células Escamosas/microbiologia , Proteobactérias/metabolismo , Reprodutibilidade dos Testes , Fumantes , Proteína Supressora de Tumor p53/metabolismo
5.
Cancer Epidemiol Biomarkers Prev ; 16(1): 174-7, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17220349

RESUMO

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.


Assuntos
Carcinoma Papilar/genética , Polimorfismo Genético , Proteínas Proto-Oncogênicas c-ret/genética , Receptores da Tireotropina/genética , Neoplasias da Glândula Tireoide/genética , Adulto , Idoso , Carcinoma Papilar/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-ret/sangue , Receptores da Tireotropina/sangue , Neoplasias da Glândula Tireoide/sangue
6.
BMC Genet ; 8: 68, 2007 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-17916242

RESUMO

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.


Assuntos
Efeito Fundador , Genes BRCA1 , Predisposição Genética para Doença , Judeus/genética , Neoplasias da Mama/etnologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Feminino , Genoma Humano , Haplótipos , Humanos , Desequilíbrio de Ligação , Neoplasias Ovarianas/etnologia , Neoplasias Ovarianas/genética , Polimorfismo de Nucleotídeo Único , Deleção de Sequência
7.
Hum Mutat ; 27(6): 538-44, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16652348

RESUMO

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.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Mutação de Sentido Incorreto , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Alelos , Proteínas Mutadas de Ataxia Telangiectasia , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Polônia/epidemiologia , Fatores de Risco , Estados Unidos/epidemiologia
8.
Hum Mutat ; 22(2): 121-8, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12872252

RESUMO

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.


Assuntos
Neoplasias da Mama Masculina/genética , Neoplasias da Mama/genética , Análise Mutacional de DNA/métodos , Proteínas de Ligação a DNA , Genes BRCA1 , Genes BRCA2 , Neoplasias Ovarianas/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Fatores de Transcrição de Zíper de Leucina Básica , DNA de Neoplasias/genética , Família , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Regulação Neoplásica da Expressão Gênica/genética , Haplótipos/genética , Humanos , Zíper de Leucina/genética , Desequilíbrio de Ligação/genética , Masculino , Mutação de Sentido Incorreto/genética , Linhagem , Proteínas Repressoras/fisiologia , Fatores de Transcrição/fisiologia , Dedos de Zinco/genética
9.
J Thorac Oncol ; 5(9): 1447-53, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20651610

RESUMO

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.


Assuntos
Mutação/genética , Proteínas Proto-Oncogênicas c-kit/genética , Timoma/genética , Neoplasias do Timo/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , DNA de Neoplasias/genética , Éxons/genética , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Prognóstico , Proteínas Proto-Oncogênicas c-kit/metabolismo , Estudos Retrospectivos , Taxa de Sobrevida , Timoma/metabolismo , Timoma/patologia , Neoplasias do Timo/metabolismo , Neoplasias do Timo/patologia , Análise Serial de Tecidos
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