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1.
Genes Chromosomes Cancer ; 57(11): 564-572, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30203894

RESUMO

Telomere repeats at chromosomal ends, critical for genomic integrity, undergo age-dependent attrition and telomere length has been associated with different disorders including cancers. In this study, based on 1469 patients and 1158 healthy controls, we show a statistically significant (P = 6 × 10-10 ) association between increased telomere length and melanoma risk. Mendelian randomization, using 5 telomere length-associated polymorphisms, ruled out confounding factors or reverse causality and showed association between increased telomere length and melanoma risk with odds ratio of 2.66 (95% confidence interval: 2.07-3.25). Age-dependent telomere attrition was faster in melanoma cases than controls (P = .01). The carriers of a highly penetrant germline -57A>C TERT promoter mutation, in a previously reported melanoma family, had longer telomeres than the noncarriers. The mutation causes increased TERT and telomerase levels through creation of a binding motif for E-twenty six (ETS) transcription factors and the carriers develop melanoma with an early age of onset and rapid progression to metastasis. In analogy, we hypothesize that increased telomere length in melanoma patients reflects stochastic increased telomerase levels due to common genetic variation. Paradoxically, we observed shorter telomeres (P = 1 × 10-5 ) in primary tumors from unrelated melanoma patients with (121) than without (170) somatic TERT promoter mutations that similar to the germline mutation, also create binding motifs for ETS transcription factors. However, the age-dependent telomere attrition was faster in tumors with the TERT promoter mutations than in those without such mutations. Besides a robust association between increased telomere length and risk, our data show a perturbed telomere homeostasis in melanoma.


Assuntos
Predisposição Genética para Doença , Melanoma , Regiões Promotoras Genéticas/genética , Telomerase/genética , Telômero/genética , Adulto , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Melanoma/epidemiologia , Melanoma/genética , Pessoa de Meia-Idade , Mutação/genética , Adulto Jovem
2.
Int J Cancer ; 141(5): 867-876, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28407294

RESUMO

Study of genetic alterations, inherited or acquired, that increase the risk or drive cancers and many other diseases had remained mostly confined to coding sequences of the human genome. Data from genome wide associations studies, development of the Encyclopedia of DNA Elements (ENCODE), and a spurt in detection of driver somatic mutations have shifted focus towards noncoding regions of the human genome. The majority of genetic variants robustly associated with cancers and other syndromes identified through genome wide studies are located within noncoding regulatory regions of the genome. Genome wide techniques have put an emphasis on the role of three-dimensional chromosomal structures and cis-acting elements in regulations of different genes. The variants within noncoding genomic regions can potentially alter a number of regulatory elements including promoters, enhancers, insulators, noncoding long RNAs and others that affect cancers and various diseases through altered expression of critical genes. With effect of genetic alterations within regulatory elements dependent on other partner molecules like transcription factors and histone marks, an understanding of such modifications can potentially identify extended therapeutic targets. That concept has been augmented by the detection of driver somatic noncoding mutations within the promoter region of the telomerase reverse transcriptase (TERT) gene in different cancers. The acquired somatic noncoding mutations within different regulatory elements are now being reported in different cancers with an increased regularity. In this review we discuss the occurrence and impact of germline and somatic alterations within the TERT promoter and other genomic regulatory elements.


Assuntos
Variação Genética/genética , Regiões Promotoras Genéticas/genética , Elementos Reguladores de Transcrição/genética , Telomerase/genética , Animais , Humanos
3.
Neuroradiology ; 59(12): 1223-1231, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28894890

RESUMO

PURPOSE: Magnetic resonance (MR) imaging biomarkers can assist in the non-invasive assessment of the genetic status in glioblastomas (GBMs). Telomerase reverse transcriptase (TERT) promoter mutations are associated with a negative prognosis. This study was performed to identify MR imaging biomarkers to forecast the TERT mutation status. METHODS: Pre-operative MRIs of 64/67 genetically confirmed primary GBM patients (51/67 TERT-mutated with rs2853669 polymorphism) were analyzed according to Visually AcceSAble Rembrandt Images (VASARI) ( https://wiki.cancerimagingarchive.net/display/Public/VASARI+Research+Project ) imaging criteria by three radiological raters. TERT mutation and O6-methylguanine-DNA methyltransferase (MGMT) hypermethylation data were obtained through direct and pyrosequencing as described in a previous study. Clinical data were derived from a prospectively maintained electronic database. Associations of potential imaging biomarkers and genetic status were assessed by Fisher and Mann-Whitney U tests and stepwise linear regression. RESULTS: No imaging biomarkers could be identified to predict TERT mutational status (alone or in conjunction with TERT promoter polymorphism rs2853669 AA-allele). TERT promoter mutations were more common in patients with tumor-associated seizures as first symptom (26/30 vs. 25/37, p = 0.07); these showed significantly smaller tumors [13.1 (9.0-19.0) vs. 24.0 (16.6-37.5) all cm3; p = 0.007] and prolonged median overall survival [17.0 (11.5-28.0) vs. 9.0 (4.0-12.0) all months; p = 0.02]. TERT-mutated GBMs were underrepresented in the extended angularis region (p = 0.03), whereas MGMT-methylated GBMs were overrepresented in the corpus callosum (p = 0.03) and underrepresented temporomesially (p = 0.01). CONCLUSION: Imaging biomarkers for prediction of TERT mutation status remain weak and cannot be derived from the VASARI protocol. Tumor-associated seizures are less common in TERT mutated glioblastomas.


Assuntos
Neoplasias Encefálicas/genética , Glioblastoma/genética , Imageamento por Ressonância Magnética/métodos , Telomerase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo de Nucleotídeo Único , Prognóstico , Regiões Promotoras Genéticas
4.
Int J Cancer ; 139(1): 75-84, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26875008

RESUMO

Despite advances in targeted therapies, the treatment of advanced melanoma remains an exercise in disease management, hence a need for biomarkers for identification of at-risk primary melanoma patients. In this study, we aimed to assess the prognostic value of TERT promoter mutations in primary melanomas. Tumors from 300 patients with stage I/II melanoma were sequenced for TERT promoter and BRAF/NRAS mutations. Cumulative curves were drawn for patients with and without mutations with progression-free and melanoma-specific survival as outcomes. Cox proportional hazard regression models were used to determine the effect of the mutations on survivals. Individually, presence of TERT promoter and BRAF/NRAS mutations associated with poor disease-free and melanoma-specific survival with modification of the effect by the rs2853669 polymorphism within the TERT promoter. Hazard ratio (HR) for simultaneous occurrence of TERT promoter and BRAF/NRAS mutations for disease-free survival was 2.3 (95% CI 1.2-4.4) and for melanoma-specific survival 5.8 (95% CI 1.9-18.3). The effect of the mutations on melanoma-specific survival in noncarriers of variant allele of the polymorphism was significant (HR 4.5, 95% CI 1.4-15.2) but could not be calculated for the carriers due to low number of events. The variant allele per se showed association with increased survival (HR 0.3, 95% CI 0.1-0.9). The data in this study provide preliminary evidence that TERT promoter mutations in combination with BRAF/NRAS mutations can be used to identify patients at risk of aggressive disease and the possibility of refinement of the classification with inclusion of the rs2853669 polymorphism within TERT promoter.


Assuntos
Biomarcadores Tumorais/genética , Melanoma/genética , Prognóstico , Telomerase/genética , Adulto , Idoso , Intervalo Livre de Doença , GTP Fosfo-Hidrolases/genética , Humanos , Estimativa de Kaplan-Meier , Melanoma/patologia , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Regiões Promotoras Genéticas , Modelos de Riscos Proporcionais , Proteínas Proto-Oncogênicas B-raf/genética
5.
Proc Natl Acad Sci U S A ; 110(43): 17426-31, 2013 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-24101484

RESUMO

The telomerase reverse transcriptase (TERT) promoter, an important element of telomerase expression, has emerged as a target of cancer-specific mutations. Originally described in melanoma, the mutations in TERT promoter have been shown to be common in certain other tumor types that include glioblastoma, hepatocellular carcinoma, and bladder cancer. To fully define the occurrence and effect of the TERT promoter mutations, we investigated tumors from a well-characterized series of 327 patients with urothelial cell carcinoma of bladder. The somatic mutations, mainly at positions -124 and -146 bp from ATG start site that create binding motifs for E-twenty six/ternary complex factors (Ets/TCF), affected 65.4% of the tumors, with even distribution across different stages and grades. Our data showed that a common polymorphism rs2853669, within a preexisting Ets2 binding site in the TERT promoter, acts as a modifier of the effect of the mutations on survival and tumor recurrence. The patients with the mutations showed poor survival in the absence [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.02-4.70] but not in the presence (HR 0.42, 95% CI 0.18-1.01) of the variant allele of the polymorphism. The mutations in the absence of the variant allele were highly associated with the disease recurrence in patients with Tis, Ta, and T1 tumors (HR 1.85, 95% CI 1.11-3.08). The TERT promoter mutations are the most common somatic lesions in bladder cancer with clinical implications. The association of the mutations with patient survival and disease recurrence, subject to modification by a common polymorphism, can be a unique putative marker with individualized prognostic potential.


Assuntos
Carcinoma de Células de Transição/genética , Mutação , Polimorfismo de Nucleotídeo Único , Telomerase/genética , Neoplasias da Bexiga Urinária/genética , Idoso de 80 Anos ou mais , Sequência de Bases , Biomarcadores Tumorais/genética , Carcinoma de Células de Transição/patologia , Linhagem Celular Tumoral , Análise Mutacional de DNA/estatística & dados numéricos , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Luciferases/genética , Luciferases/metabolismo , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Recidiva Local de Neoplasia , Prognóstico , Regiões Promotoras Genéticas/genética , Modelos de Riscos Proporcionais , Neoplasias da Bexiga Urinária/patologia
6.
Int J Cancer ; 136(10): 2448-52, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25331263

RESUMO

We screened promoter region of the telomerase reverse transcriptase (TERT) for activating somatic mutations in 188 tumors from patients with clear cell renal cell carcinoma (ccRCC). Twelve tumors (6.4%) carried a mutation within the core promoter region of the gene. The mutations were less frequent in high grade tumors compared to low grade tumors [odds ratio (OR) = 0.15, 95% confidence interval (CI) = 0.03-0.72, p = 0.02]. Multivariate analysis for cause specific survival showed statistically significant poor outcome in patients with TERT promoter mutations [hazard ratio (HR) = 2.90, 95% CI = 1.13-7.39, p = 0.03]. A common polymorphism (rs2853669) within the locus seemed to act as a modifier of the effect of the mutations on patient survival as the noncarriers of the variant allele with the TERT promoter mutations showed worst survival (HR = 3.34, 95% CI = 1.24-8.98, p = 0.02). We also measured relative telomere length (RTL) in tumors and difference between tumors with and without the TERT promoter mutations was not statistically significant. Similarly, no difference in patient survival based on RTL in tumors was observed. Our study showed a relatively low frequency of TERT promoter mutations in ccRCC. Nevertheless, patients with the mutations, particularly in the absence of the rs2853669 variant showed the worst disease-specific survival. Thus, it is possible that the TERT promoter mutations define a small subset of tumors with an aggressive behavior.


Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Regiões Promotoras Genéticas , Telomerase/genética , Telômero/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/genética , Feminino , Humanos , Neoplasias Renais/genética , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo de Nucleotídeo Único , Análise de Sobrevida
8.
Int J Cancer ; 137(7): 1621-9, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25809917

RESUMO

Mutations in the promoter of the telomerase reverse transcriptase (TERT) and fibroblast growth factor receptor 3 (FGFR3) genes constitute the most recurrent somatic alterations in urothelial carcinoma of bladder. In this study, we screened DNA from 327 urothelial bladder carcinomas from well-documented patients, with different stages and grades and known TERT promoter mutational status, for FGFR3 alterations and measured relative telomere length (RTL). Although, the frequency of the TERT promoter mutations was higher than those in FGFR3; however, the alterations at the two loci occurred together more frequently than per chance [Odds ratio (OR) = 4.93, 95% CI = 2.72-8.92, p < 0.0001]. While tumors with TERT promoter and FGFR3 mutations had shorter RTL than those without mutations (p < 0.0001), the TERT promoter mutations in conjunction with the common allele of the rs2853669 polymorphism defined sub-group of patients with an observed decreased overall survival (OR = 2.15, 95% CI = 1.00-4.61) and increased recurrence in patients with TaG1+TaG2 disease categories (OR = 3.68, 95%CI = 1.12-12.05). The finding of shorter telomeres in tumors with TERT promoter and/or FGFR3 mutations than without mutations implies mechanistic relevance of telomere biology in cancer progression. The observed association with recurrence and survival shows that the TERT promoter mutations can potentially be used as markers to refine selection of patients for different treatments. The overwhelming frequency of the TERT promoter mutations also represents a case for development of an eventual therapeutic target.


Assuntos
Mutação , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Telomerase/genética , Telômero/genética , Neoplasias da Bexiga Urinária/genética , Idoso , Feminino , Humanos , Masculino , Regiões Promotoras Genéticas , Neoplasias da Bexiga Urinária/patologia
9.
Vet Clin North Am Exot Anim Pract ; 24(1): 153-174, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33189248

RESUMO

Birds of prey are highly complex and intelligent species with many of their activities deeply rooted in modal action patterns, such as foraging, courtship and nest building, migration, bathing, or preening. Raptors in managed care are susceptible to presenting undesired behavior when the environment provides antecedents for these behaviors and consequences to maintain them. This article aims to describe concepts of behavior in birds of prey in managed care, with inferences from their wild counterparts, to assist in understanding the etiologies and management of undesired behaviors.


Assuntos
Criação de Animais Domésticos , Comportamento Animal , Aves Predatórias , Bem-Estar do Animal , Animais
10.
Sci Rep ; 10(1): 8005, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32409749

RESUMO

Basal cell carcinoma (BCC) represents the most commonly diagnosed human cancer among persons of European ancestry with etiology mainly attributed to sun-exposure. In this study we investigated mutations in coding and flanking regions of PTCH1 and TP53 and noncoding alterations in the TERT and DPH3 promoters in 191 BCC tumors. In addition, we measured CpG methylation within the TERT hypermethylated oncological region (THOR) and transcription levels of the reverse transcriptase subunit. We observed mutations in PTCH1 in 58.6% and TP53 in 31.4% of the tumors. Noncoding mutations in TERT and DPH3 promoters were detected in 59.2% and 38.2% of the tumors, respectively. We observed a statistically significant co-occurrence of mutations at the four investigated loci. While PTCH1 mutations tended to associate with decreased patient age at diagnosis; TP53 mutations were associated with light skin color and increased number of nevi; TERT and DPH3 promoter with history of cutaneous neoplasms in BCC patients. Increased reverse transcriptase subunit expression was observed in tumors with TERT promoter mutations and not with THOR methylation. Our study signifies, in addition to the protein altering mutations in the PTCH1 and TP53 genes, the importance of noncoding mutations in BCC, particularly functional alterations in the TERT promoter.


Assuntos
Biomarcadores Tumorais , Carcinoma Basocelular/genética , Mutação , Fases de Leitura Aberta , Regiões não Traduzidas , Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Neoplasias Cutâneas/genética
11.
Clin Cancer Res ; 26(14): 3819-3830, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32317288

RESUMO

PURPOSE: Human malignant pleural mesothelioma (MPM) is characterized by dismal prognosis. Consequently, dissection of molecular mechanisms driving malignancy is of key importance. Here we investigate whether activating mutations in the telomerase reverse transcriptase (TERT) gene promoter are present in MPM and associated with disease progression, cell immortalization, and genomic alteration patterns. EXPERIMENTAL DESIGN: TERT promoters were sequenced in 182 MPM samples and compared with clinicopathologic characteristics. Surgical specimens from 45 patients with MPM were tested for in vitro immortalization. The respective MPM cell models (N = 22) were analyzed by array comparative genomic hybridization, gene expression profiling, exome sequencing as well as TRAP, telomere length, and luciferase promoter assays. RESULTS: TERT promoter mutations were detected in 19 of 182 (10.4%) MPM cases and significantly associated with advanced disease and nonepithelioid histology. Mutations independently predicted shorter overall survival in both histologic MPM subtypes. Moreover, 9 of 9 (100%) mutated but only 13 of 36 (36.1%) wild-type samples formed immortalized cell lines. TERT promoter mutations were associated with enforced promoter activity and TERT mRNA expression, while neither telomerase activity nor telomere lengths were significantly altered. TERT promoter-mutated MPM cases exhibited distinctly reduced chromosomal alterations and specific mutation patterns. While BAP1 mutations/deletions were exclusive with TERT promoter mutations, homozygous deletions at the RBFOX1 and the GSTT1 loci were clearly enriched in mutated cases. CONCLUSIONS: TERT promoter mutations independently predict a dismal course of disease in human MPM. The altered genomic aberration pattern indicates that TERT promoter mutations identify a novel, highly aggressive MPM subtype presumably based on a specific malignant transformation process.


Assuntos
Biomarcadores Tumorais/genética , Mesotelioma Maligno/genética , Neoplasias Pleurais/genética , Telomerase/genética , Idoso , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Transformação Celular Neoplásica/genética , Hibridização Genômica Comparativa , Análise Mutacional de DNA , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Mesotelioma Maligno/mortalidade , Mesotelioma Maligno/patologia , Pessoa de Meia-Idade , Mutação , Pleura/patologia , Neoplasias Pleurais/mortalidade , Neoplasias Pleurais/patologia , Prognóstico , Regiões Promotoras Genéticas/genética , Estudos Retrospectivos , Sequenciamento do Exoma
12.
Mutat Res Rev Mutat Res ; 771: 15-31, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28342451

RESUMO

Telomere repeats at chromosomal ends, critical to genome integrity, are maintained through an elaborate network of proteins and pathways. Shelterin complex proteins shield telomeres from induction of DNA damage response to overcome end protection problem. A specialized ribonucleic protein, telomerase, maintains telomere homeostasis through repeat addition to counter intrinsic shortcomings of DNA replication that leads to gradual sequence shortening in successive mitoses. The biogenesis and recruitment of telomerase composed of telomerase reverse transcriptase (TERT) subunit and an RNA component, takes place through the intricate machinery that involves an elaborate number of molecules. The synthesis of telomeres remains a controlled and limited process. Inherited mutations in the molecules involved in the process directly or indirectly cause telomeropathies. Telomerase, while present in stem cells, is deactivated due to epigenetic silencing of the rate-limiting TERT upon differentiation in most of somatic cells with a few exceptions. However, in most of the cancer cells telomerase reactivation remains a ubiquitous process and constitutes one of the major hallmarks. Discovery of mutations within the core promoter of the TERT gene that create de novo binding sites for E-twenty-six (ETS) transcription factors provided a mechanism for cancer-specific telomerase reactivation. The TERT promoter mutations occur mainly in tumors from tissues with low rates of self-renewal. In melanoma, glioma, hepatocellular carcinoma, urothelial carcinoma and others, the promoter mutations have been shown to define subsets of patients with adverse disease outcomes, associate with increased transcription of TERT, telomerase reactivation and affect telomere length; in stem cells the mutations inhibit TERT silencing following differentiation into adult cells. The TERT promoter mutations cause an epigenetic switch on the mutant allele along with recruitment of pol II following the binding of GABPA/B1 complex that leads to mono-allelic expression. Thus, the TERT promoter mutations hold potential as biomarkers as well as future therapeutic targets.


Assuntos
Mutação , Regiões Promotoras Genéticas , Telomerase/genética , Telômero , Humanos
13.
J Cancer Res Clin Oncol ; 143(4): 613-617, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27990595

RESUMO

BACKGROUND: TERT promoter mutations were detected at high frequencies in several cancer types including melanoma. Previous reports showed that these recurrent mutations increase TERT gene expression and the use of TERT mutation status as prognostic factor was suggested. OBJECTIVES: Here we screen a panel of 115 melanoma tumor samples from Austrian patients to evaluate the prevalence and distribution of TERT promoter mutations. The association with clinical and tumor characteristics and the effect on overall survival was analyzed. METHODS: Genomic DNA from formalin-fixed paraffin-embedded tumor samples was isolated followed by PCR amplification, Sanger sequencing and statistical analysis. RESULTS: We identified TERT promoter mutations in 63 of 115 (54.8%) tumor samples. No statistical significant difference in mutation frequency between primary (22/40 [55%]) and metastatic lesions (41/75 [54.7%]) was detected. BRAF-/NRAS-mutated tumors showed a higher frequency of TERT mutations (pT OR 2.24, 95% CI 0.56-9.02, p = 0.3) (met OR 2.74, 95% CI 0.98-7.66, p = 0.05). In primary melanoma, the presence of alterations in TERT was associated with the carrier status of a common single-nucleotide polymorphism rs2853669 (OR 4.55, CI 1.18-17.52, p = 0.03). In this patient cohort, TERT promoter mutations were not associated with clinical characteristics such as the presence of ulceration or Breslow thickness or showed an effect on overall survival. CONCLUSION: Alterations in the TERT promoter region are one of the most frequent mutations in melanoma. Based on this analysis and preliminary evidence, prospective studies will be needed to evaluate the reliability of TERT promoter mutations as prognostic factors in melanoma.


Assuntos
Melanoma/genética , Metástase Neoplásica/genética , Regiões Promotoras Genéticas , Telomerase/genética , Áustria , Feminino , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade
14.
Oncotarget ; 8(22): 36639-36649, 2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28410231

RESUMO

Seborrheic keratoses are common benign epidermal lesions that are associated with increased age and sun-exposure. Those lesions despite harboring multiple somatic alterations in contrast to malignant tumors appear to be genetically stable. In order to investigate and characterize the presence of recurrent mutations, we performed exome sequencing on DNA from one seborrheic keratosis lesion and corresponding blood cells from the same patients with follow up investigation of alterations identified by exome sequencing in 24 additional lesions from as many patients. In addition we investigated alterations in all lesions at specific genes loci that included FGFR3, PIK3CA, HRAS, BRAF, CDKN2A and TERT and DHPH3 promoters. The exome sequencing data indicated three mutations per Mb of the targeted sequence. The mutational pattern depicted typical UV signature with majority of alterations being C>T and CC>TT base changes at dipyrimidinic sites. The FGFR3 mutations were the most frequent, detected in 12 of 25 (48%) lesions, followed by the PIK3CA (32%), TERT promoter (24%) and DPH3 promoter mutations (24%). TERT promoter mutations associated with increased age and were present mainly in the lesions excised from head and neck. Three lesions also carried alterations in CDKN2A. FGFR3, TERT and DPH3 expression did not correlate with mutations in the respective genes and promoters; however, increased FGFR3 transcript levels were associated with increased FOXN1 levels, a suggested positive feedback loop that stalls malignant progression. Thus, in this study we report overall mutation rate through exome sequencing and show the most frequent mutations seborrheic keratosis.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Ceratose Seborreica/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Biomarcadores , Análise Mutacional de DNA , Feminino , Expressão Gênica , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo de Nucleotídeo Único , Sequenciamento do Exoma
15.
Oncotarget ; 7(13): 16490-504, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-26909863

RESUMO

Genomic locus at chromosome 9p21 that contains the CDKN2A and CDKN2B tumor suppressor genes is inactivated through mutations, deletions and promoter methylation in multiple human cancers. Additionally, the locus encodes an anti-sense RNA (ANRIL). Both hemizygous and homozygous deletions at the locus targeting multiple genes are fairly common in different cancers. We in this study investigated breakpoints in five melanoma cell lines, derived from metastasized tumors, with previously identified homozygous deletions using array comparative genomic hybridization (aCGH). For breakpoint mapping, we used primer approximation multiplex PCR (PAMP) and inverse PCR techniques. Our results showed that three cell lines carried complex rearrangements. In two other cell lines, with focal deletions of 141 kb and 181 kb, we identified fusion gene products, involving MTAP and ANRIL. We also confirmed the complex rearrangements and focal deletions in DNA from tumor tissues corresponding to three cell lines. The rapid amplification of 3'cDNA ends (3'RACE) carried out on transcripts resulted in identification of three isoforms of MTAP-ANRIL fusion gene. Screening of cDNA from 64 melanoma cell lines resulted in detection of fusion transcripts in 13 (20%) cell lines that involved exons 4-7 of the MTAP and exon 2 or 5 of the ANRIL genes. We also detected fusion transcripts involving MTAP and ANRIL in two of the seven primary melanoma tumors with focal deletion at the locus. The results from the study, besides identifying complex rearrangements involving CDKN2A locus, show frequent occurrence of fusion transcripts involving MTAP and ANRIL genes.


Assuntos
Pontos de Quebra do Cromossomo , Mapeamento Cromossômico/métodos , Inibidor de Quinase Dependente de Ciclina p18/genética , Deleção de Genes , Melanoma/genética , Hibridização Genômica Comparativa , Inibidor p16 de Quinase Dependente de Ciclina , Fusão Gênica , Humanos , Purina-Núcleosídeo Fosforilase/genética , RNA Longo não Codificante/genética , Transcrição Gênica
16.
Oncotarget ; 7(33): 53127-53136, 2016 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-27449293

RESUMO

The mechanism of telomerase re-activation in cancer had remained elusive until the discovery of frequent mutations in the promoter of the TERT gene that encodes the catalytic reverse transcriptase subunit of telomerase. We investigated the regulation of TERT expression in melanoma cell lines and our results show that promoter mutations render TERT expression dependent on MAPK activation due to oncogenic BRAF or NRAS mutations. Mutations in the TERT promoter create binding sites for ETS transcription factors. ETS1, expressed in melanoma cell lines, undergoes activating phosphorylation by ERK at Thr38 residue as a consequence of constitutively activated MAPK pathway. We demonstrate that ETS1 binds on the mutated TERT promoter leading to the re-expression of the gene. The inhibition of ETS1 resulted in reduced TERT expression. We provide evidence that the TERT promoter mutations provide a direct link between TERT expression and MAPK pathway activation due to BRAF or NRAS mutations via the transcription factor ETS1.


Assuntos
Regulação Neoplásica da Expressão Gênica , Sistema de Sinalização das MAP Quinases/genética , Mutação , Regiões Promotoras Genéticas/genética , Telomerase/genética , Linhagem Celular Tumoral , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteína Proto-Oncogênica c-ets-1/genética , Proteína Proto-Oncogênica c-ets-1/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Interferência de RNA , Telomerase/metabolismo
17.
Oncotarget ; 6(12): 10617-33, 2015 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-25797251

RESUMO

In this report on 303 gliomas we show the highest frequency of TERT promoter mutations in gliobastomas (80%) followed by oligodendrogliomas (70%) and astrocytomas (39%). We observed positive association between TERT promoter and IDH mutations in oligodendroglial tumors (OR = 26.3; 95% CI 2.5-250.2) and inverse association in primary glioblastomas (OR = 0.13; 95% CI 0.03-0.58). Tumors with TERT promoter mutations compared to those without showed increased TERT transcription; we also showed difference in the transcription levels due to the two main mutations. Tumors with TERT promoter mutations had shorter telomeres than those without. The patients with only TERT promoter mutations showed worst survival (median survival 14.6 months) and patients with both IDH and TERT promoter mutations showed best survival (246.5 months). In patients with astrocytoma, the TERT promoter mutations only associated with poor survival (P < 0.0001); IDH mutations and 1p/19q deletions associated with increased survival (P = 0.0004). TERT promoter mutations in low grade gliomas associated with reduced progression free survival (HR 10.2; 95% CI 1.9 - 55.9). While our data affirm the role of TERT promoter mutations in glial tumors, effects on transcription and telomere length emphasise the importance of telomere biology in disease genesis and outcome.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , Mutação , Telomerase/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/patologia , Criança , Intervalo Livre de Doença , Feminino , Glioma/enzimologia , Glioma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/enzimologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Prognóstico , Regiões Promotoras Genéticas , Telômero/genética , Adulto Jovem
19.
Neuro Oncol ; 17(1): 45-52, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25140036

RESUMO

BACKGROUND: Activating somatic mutations in the promoter region of the telomerase reverse transcriptase gene (TERT) have been detected in several cancers. In this study we investigated the TERT promoter mutations and their impact on patient survival in World Health Organization grade IV glioblastoma multiforme (GBM). METHODS: The TERT core promoter region containing the previously described mutations and a common functional polymorphism (rs2853669) was sequenced in tumors and blood samples from 192 GBM patients. O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was assessed by pyrosequencing in 177 (92.2%) cases. Relevant clinical data were obtained from a prospectively maintained electronic database. RESULTS: We detected specific (-124 C>T and -146 C>T) TERT promoter mutations in 143/178 (80.3%) primary GBM and 4/14 (28.6%) secondary GBM (P < .001). The presence of TERT mutations was associated with poor overall survival, and the effect was confined to the patients who did not carry the variant G-allele for the rs2853669 polymorphism. An exploratory analysis suggested that TERT mutations might be prognostic only in patients who had incomplete resections and no temozolomide chemotherapy. CONCLUSIONS: In this study, specific TERT promoter mutations were markers of primary GBM and predicted patient survival in conjunction with a common functional polymorphism. The prognostic impact of TERT mutations was absent in patients with complete resections and temozolomide chemotherapy. If confirmed in additional studies, these findings may have clinical implications, that is, TERT mutations appear to characterize tumors that require aggressive treatment.


Assuntos
Glioblastoma/genética , Glioblastoma/mortalidade , Mutação , Telomerase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Feminino , Genótipo , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Regiões Promotoras Genéticas , Proteínas Supressoras de Tumor/genética , Adulto Jovem
20.
Oncotarget ; 6(34): 35922-30, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26416425

RESUMO

Recent reports suggested frequent occurrence of cancer associated somatic mutations within regulatory elements of the genome. Based on initial exome sequencing of 21 melanomas, we report frequent somatic mutations in skin cancers in a bidirectional promoter of diphthamide biosynthesis 3 (DPH3) and oxidoreductase NAD-binding domain containing 1 (OXNAD1) genes. The UV-signature mutations occurred at sites adjacent and within a binding motif for E-twenty six/ternary complex factors (Ets/TCF), at -8 and -9 bp from DPH3 transcription start site. Follow up screening of 586 different skin lesions showed that the DPH3 promoter mutations were present in melanocytic nevi (2/114; 2%), melanoma (30/304; 10%), basal cell carcinoma of skin (BCC; 57/137; 42%) and squamous cell carcinoma of skin (SCC; 12/31; 39%). Reporter assays carried out in one melanoma cell line for DPH3 and OXNAD1 orientations showed statistically significant increased promoter activity due to -8/-9CC > TT tandem mutations; although, no effect of the mutations on DPH3 and OXNAD1 transcription in tumors was observed. The results from this study show occurrence of frequent somatic non-coding mutations adjacent to a pre-existing binding site for Ets transcription factors within the directional promoter of DPH3 and OXNAD1 genes in three major skin cancers. The detected mutations displayed typical UV signature; however, the functionality of the mutations remains to be determined.


Assuntos
Carcinoma de Células Escamosas/genética , Proteínas de Transporte/genética , Neoplasias Cutâneas/genética , Sequência de Aminoácidos , Sequência de Bases , Carcinoma de Células Escamosas/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Melanoma/genética , Melanoma/patologia , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Neoplasias Cutâneas/patologia
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