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1.
Genes Dev ; 30(7): 772-85, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26988419

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a lethal form of cancer with few therapeutic options. We found that levels of the lysine methyltransferase SMYD2 (SET and MYND domain 2) are elevated in PDAC and that genetic and pharmacological inhibition of SMYD2 restricts PDAC growth. We further identified the stress response kinase MAPKAPK3 (MK3) as a new physiologic substrate of SMYD2 in PDAC cells. Inhibition of MAPKAPK3 impedes PDAC growth, identifying a potential new kinase target in PDAC. Finally, we show that inhibition of SMYD2 cooperates with standard chemotherapy to treat PDAC cells and tumors. These findings uncover a pivotal role for SMYD2 in promoting pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático/enzimologia , Histona-Lisina N-Metiltransferase/metabolismo , Neoplasias Pancreáticas/enzimologia , Animais , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Inibidores Enzimáticos/farmacologia , Células HEK293 , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Estresse Fisiológico
2.
Crit Rev Toxicol ; 53(10): 658-701, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38050998

RESUMO

Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients.


Assuntos
Neoplasias , Nitrosaminas , Tabaco sem Fumaça , Humanos , Carcinógenos/toxicidade , Mutagênicos , Neoplasias/induzido quimicamente , Nitratos , Nitritos , Nitrosaminas/toxicidade , Nitrosaminas/química , Nitrosaminas/metabolismo , Tabaco sem Fumaça/toxicidade
3.
Curr Opin Oncol ; 33(2): 149-158, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33405482

RESUMO

PURPOSE OF REVIEW: Virtually all viruses have evolved molecular instruments to circumvent cell mechanisms that may hamper their replication, dissemination, or persistence. Among these is p53, a key gatekeeper for cell division and survival that also regulates innate immune responses. This review summarizes the strategies used by different viruses and discusses the mechanisms deployed by SARS-CoV to target p53 activities. RECENT FINDINGS: We propose a typology for the strategies used by different viruses to address p53 functions: hit and run (e.g. IAV, ZIKV), hide and seek (e.g. HIV1), kidnap and exploit (e.g. EBV, HSV1), dominate and suppress (e.g. HR HPV). We discuss the mechanisms by which SARS nsp3 protein targets p53 for degradation and we speculate on the significance for Covid-19 pathogenesis and risk of cancer. SUMMARY: p53 may operate as an intracellular antiviral defense mechanism. To circumvent it, SARS viruses adopt a kidnap and exploit strategy also shared by several viruses with transforming potential. This raises the question of whether SARS infections may make cells permissive to oncogenic DNA damage.


Assuntos
COVID-19/virologia , SARS-CoV-2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Humanos
4.
Int J Mol Sci ; 22(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073316

RESUMO

Circulating cell-free DNA (cfDNA) is emerging as a potential tumor biomarker. CfDNA-based biomarkers may be applicable in tumors without an available non-invasive screening method among at-risk populations. Esophageal squamous cell carcinoma (ESCC) and residents of the Asian cancer belt are examples of those malignancies and populations. Previous epidemiological studies using cfDNA have pointed to the need for high volumes of good quality plasma (i.e., >1 mL plasma with 0 or 1 cycles of freeze-thaw) rather than archival serum, which is often the main available source of cfDNA in retrospective studies. Here, we have investigated the concordance of TP53 mutations in tumor tissue and cfDNA extracted from archival serum left-over from 42 cases and 39 matched controls (age, gender, residence) in a high-risk area of Northern Iran (Golestan). Deep sequencing of TP53 coding regions was complemented with a specialized variant caller (Needlestack). Overall, 23% to 31% of mutations were concordantly detected in tumor and serum cfDNA (based on two false discovery rate thresholds). Concordance was positively correlated with high cfDNA concentration, smoking history (p-value = 0.02) and mutations with a high potential of neoantigen formation (OR; 95%CI = 1.9 (1.11-3.29)), suggesting that tumor DNA release in the bloodstream might reflect the effects of immune and inflammatory context on tumor cell turnover. We identified TP53 mutations in five controls, one of whom was subsequently diagnosed with ESCC. Overall, the results showed that cfDNA mutations can be reliably identified by deep sequencing of archival serum, with a rate of success comparable to plasma. Nonetheless, 70% non-identifiable mutations among cancer patients and 12% mutation detection in controls are the main challenges in applying cfDNA to detect tumor-related variants when blindly targeting whole coding regions of the TP53 gene in ESCC.


Assuntos
DNA Tumoral Circulante/genética , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Mutação , Proteína Supressora de Tumor p53/genética , DNA Tumoral Circulante/sangue , Neoplasias Esofágicas/sangue , Carcinoma de Células Escamosas do Esôfago/sangue , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Soro , Proteína Supressora de Tumor p53/sangue
5.
Allergy ; 75(12): 3248-3260, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32277847

RESUMO

BACKGROUND: Allergic diseases often occur in combination (multimorbidity). Human blood transcriptome studies have not addressed multimorbidity. Large-scale gene expression data were combined to retrieve biomarkers and signaling pathways to disentangle allergic multimorbidity phenotypes. METHODS: Integrated transcriptomic analysis was conducted in 1233 participants with a discovery phase using gene expression data (Human Transcriptome Array 2.0) from whole blood of 786 children from three European birth cohorts (MeDALL), and a replication phase using RNA Sequencing data from an independent cohort (EVA-PR, n = 447). Allergic diseases (asthma, atopic dermatitis, rhinitis) were considered as single disease or multimorbidity (at least two diseases), and compared with no disease. RESULTS: Fifty genes were differentially expressed in allergic diseases. Thirty-two were not previously described in allergy. Eight genes were consistently overexpressed in all types of multimorbidity for asthma, dermatitis, and rhinitis (CLC, EMR4P, IL5RA, FRRS1, HRH4, SLC29A1, SIGLEC8, IL1RL1). All genes were replicated the in EVA-PR cohort. RT-qPCR validated the overexpression of selected genes. In MeDALL, 27 genes were differentially expressed in rhinitis alone, but none was significant for asthma or dermatitis alone. The multimorbidity signature was enriched in eosinophil-associated immune response and signal transduction. Protein-protein interaction network analysis identified IL5/JAK/STAT and IL33/ST2/IRAK/TRAF as key signaling pathways in multimorbid diseases. Synergistic effect of multimorbidity on gene expression levels was found. CONCLUSION: A signature of eight genes identifies multimorbidity for asthma, rhinitis, and dermatitis. Our results have clinical and mechanistic implications, and suggest that multimorbidity should be considered differently than allergic diseases occurring alone.


Assuntos
Asma , Hipersensibilidade , Rinite Alérgica , Rinite , Adolescente , Asma/epidemiologia , Asma/genética , Criança , Humanos , Hipersensibilidade/epidemiologia , Hipersensibilidade/genética , Multimorbidade , Rinite/epidemiologia , Rinite/genética , Rinite Alérgica/epidemiologia , Rinite Alérgica/genética , Transcriptoma
6.
BMC Cancer ; 20(1): 110, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041553

RESUMO

BACKGROUND: TP53 mutations occur in only about 3% of primary and 10-20% of relapse B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). However, alternative mechanisms may contribute to functionally impairing the p53 pathway in the absence of a mutation. Candidate mechanisms include overexpression of p53 mRNA variants encoding either dominant-negative p53 protein isoforms such as Delta40p53 and Delta133p53, or modulatory isoforms such as p53beta, which counteract the effects of Delta133p53 on replicative senescence in T-lymphocytes. METHODS: We used semi-quantitative reverse-transcriptase PCR (RT-PCR) and Western blot to investigate the expression of full length p53 (TAp53), Delta40p53, Delta133p53 or p53beta in diagnostic marrow from a clinical cohort of 50 BCP-ALL patients without TP53 mutation (29 males and 21 females, age range 2-14 years) and in the bone marrow cells of 4 healthy donors (used as controls). RESULTS: Irrespective of isoforms, levels of p53 mRNA were low in controls but were increased by 2 to 20-fold in primary or relapse BCP-ALL. TAp53 was increased in primary BCP-ALL, Delta40p53 was elevated in relapse BCP-ALL, whereas Delta133p53 and p53beta were increased in both. Next, mRNA levels were used as a basis to infer the ratio between protein isoform levels. This inference suggested that, in primary BCP-ALL, p53 was predominantly in active oligomeric conformations dominated by TAp53. In contrast, p53 mostly existed in inactive quaternary conformations containing ≥2 Delta40 or Delta133p53 in relapse BCP-ALL. Western blot analysis of blasts from BCP-ALL showed a complex pattern of N-terminally truncated p53 isoforms, whereas TAp53beta was detected as a major isoform. The hypothesis that p53 is in an active form in primary B-ALL was consistent with elevated level of p53 target genes CDKN1A and MDM2 in primary cases, whereas in relapse BCP-ALL, only CDKN1A was increased as compared to controls. CONCLUSION: Expression of p53 isoforms is deregulated in BCP-ALL in the absence of TP53 mutation, with increased expression of alternative isoforms in relapse BCP-ALL. Variations in isoform expression may contribute to functional deregulation of the p53 pathway in BCP-ALL, specifically contributing to its down-regulation in relapse forms.


Assuntos
Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Domínios e Motivos de Interação entre Proteínas/genética , Proteína Supressora de Tumor p53/genética , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Mutação , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Isoformas de Proteínas/genética , Multimerização Proteica/genética , RNA Mensageiro , Recidiva , Proteína Supressora de Tumor p53/química
7.
Hum Mutat ; 40(1): 97-105, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30352134

RESUMO

Reports of variable cancer penetrance in Li-Fraumeni syndrome (LFS) have raised questions regarding the prevalence of pathogenic germline TP53 variants. We previously reported higher-than-expected population prevalence estimates in sequencing databases composed of individuals unselected for cancer history. This study aimed to expand and further evaluate the prevalence of pathogenic and likely pathogenic germline TP53 variants in the gnomAD dataset (version r2.0.2, n = 138,632). Variants were selected and classified based on our previously published algorithm and compared with alternative estimates based on three different classification databases: ClinVar, HGMD, and the UMD_TP53 database. Conservative prevalence estimates of pathogenic and likely pathogenic TP53 variants were within the range of one carrier in 3,555-5,476 individuals. Less stringent classification increased the approximate prevalence to one carrier in every 400-865 individuals, mainly due to the inclusion of the controvertible p.N235S, p.V31I, and p.R290H variants. This study shows a higher-than-expected population prevalence of pathogenic and likely pathogenic germline TP53 variants even with the most conservative estimates. However, these estimates may not necessarily reflect the prevalence of the classical LFS phenotype, which is based upon family history of cancer. Comprehensive approaches are needed to better understand the interplay of germline TP53 variant classification, prevalence estimates, cancer penetrance, and LFS-associated phenotype.


Assuntos
Bases de Dados Genéticas , Genética Populacional , Mutação em Linhagem Germinativa/genética , Anotação de Sequência Molecular , Proteína Supressora de Tumor p53/genética , Humanos , Pessoa de Meia-Idade
8.
Curr Opin Oncol ; 31(2): 84-91, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30585860

RESUMO

PURPOSE OF REVIEW: Childhood blastomas, unlike adult cancers, originate from developing organs in which molecular and cellular features exhibit differentiation arrest and embryonic characteristics. Conventional cancer therapies, which rely on the generalized cytotoxic effect on rapidly dividing cells, may damage delicate organs in young children, leading to multiple late effects. Deep understanding of the biology of embryonal cancers is crucial in reshaping the cancer treatment paradigm for children. RECENT FINDINGS: p53 plays a major physiological role in embryonic development, by controlling cell proliferation, differentiation and responses to cellular stress. Tumor suppressor function of p53 is commonly lost in adult cancers through genetic alterations. However, both somatic and germline p53 mutations are rare in childhood blastomas, suggesting that in these cancers, p53 may be inactivated through other mechanisms than mutation. In this review, we summarize current knowledge about p53 pathway inactivation in childhood blastomas (specifically neuroblastoma, retinoblastoma and Wilms' tumor) through various upstream mechanisms. Laboratory evidence and clinical trials of targeted therapies specific to exploiting p53 upstream regulators are discussed. SUMMARY: Despite the low rate of inherent TP53 mutations, p53 pathway inactivation is a common denominator in childhood blastomas. Exploiting p53 and its regulators is likely to translate into more effective targeted therapies with minimal late effects for children. (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/COON/A23).


Assuntos
Hepatoblastoma/metabolismo , Neuroblastoma/metabolismo , Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Tumor de Wilms/metabolismo , Animais , Criança , Hepatoblastoma/patologia , Humanos , Neuroblastoma/patologia , Retinoblastoma/patologia , Tumor de Wilms/patologia
9.
Epidemiology ; 30(5): 756-767, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31373935

RESUMO

BACKGROUND: Within-subject biospecimens pooling can theoretically reduce bias in dose-response functions from biomarker-based studies when exposure assessment suffers from classical-type error. However, collecting many urine voids each day is cumbersome. We evaluated the empirical validity of a within-subject pooling approach and compared several options to avoid sampling each void. METHODS: In 16 pregnant women who collected a spot of each urine void over several nonconsecutive weeks, we compared concentrations of 10 phenols in daily, weekly, and pregnancy within-subject pools. We pooled either three or all daily samples. In a simulation study using these data, we quantified bias in dose-response functions when using one to 20 urine samples per subject to assess methylparaben (a compound with moderate within-subject variability) and bisphenol A (high variability) exposures. RESULTS: Correlations between exposure estimates from pools of all and of only three voids per day were above 0.80 for all time windows and compounds, except for benzophenone-3 and triclosan in the daily time window (correlations, 0.57-0.68). With one spot sample to assess pregnancy exposure, correlations were all below 0.74. Using only one biospecimen led to attenuation bias in the dose-response functions of 29% (methylparaben) and 69% (bisphenol A); four samples for methylparaben and 18 for bisphenol A decreased bias to 10%. CONCLUSIONS: For nonpersistent chemicals, collecting and pooling three samples per day instead of all daily samples efficiently estimates exposures over a week or more. Collecting around 20 biospecimens can strongly limit attenuation bias for nonpersistent chemicals such as bisphenol A.


Assuntos
Exposição Ambiental/análise , Poluentes Ambientais/urina , Projetos de Pesquisa Epidemiológica , Fenóis/urina , Adulto , Viés , Biomarcadores/urina , Monitoramento Ambiental/métodos , Feminino , Seguimentos , Humanos , Gravidez , Reprodutibilidade dos Testes
10.
Pediatr Blood Cancer ; 66(5): e27629, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30719841

RESUMO

INTRODUCTION: Patients with germline TP53 pathogenic variants (Li-Fraumeni syndrome [LFS]) are at extremely high lifetime risk of developing cancer. Recent data suggest that tumor surveillance for patients with LFS may improve survival through early cancer detection. The objective of this study was to assess the cost-effectiveness of a cancer surveillance strategy for patients with LFS compared with those whose tumors present clinically. METHODS: A Markov decision analytic model was developed from a third-party payer perspective to estimate cost-effectiveness of routine cancer surveillance over a patient's lifetime. The model consisted of four possible health states: no cancer, cancer, post-cancer survivorship, and death. Model outcomes were costs (2015 United States Dollars [USD]), effectiveness (life years [LY] gained), and incremental cost-effectiveness ratio (ICER; change in cost/LY gained). One-way sensitivity analyses and probabilistic sensitivity analyses examined parameter uncertainty. RESULTS: The model showed a mean cost of $46 496 and $117 102 and yielded 23 and 27 LY for the nonsurveillance and surveillance strategies, respectively. The ICER for early cancer surveillance versus no surveillance was $17 125 per additional LY gained. At the commonly accepted willingness to pay threshold of $100 000/life-year gained, surveillance had a 98% probability of being the most cost-effective strategy for early cancer detection in this high-risk population. CONCLUSIONS: Presymptomatic cancer surveillance is cost-effective for patients with germline pathogenic variants in TP53. Lack of insurance coverage or reimbursement in this population may have significant consequences and leads to undetected cancers presenting in later stages of disease with worse clinical outcomes.


Assuntos
Análise Custo-Benefício , Detecção Precoce de Câncer/economia , Síndrome de Li-Fraumeni/diagnóstico , Síndrome de Li-Fraumeni/economia , Cadeias de Markov , Anos de Vida Ajustados por Qualidade de Vida , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Síndrome de Li-Fraumeni/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estados Unidos/epidemiologia , Adulto Jovem
11.
Curr Opin Oncol ; 30(1): 23-29, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29076966

RESUMO

PURPOSE OF REVIEW: Germline pathogenic TP53 mutation may predispose to multiple cancers but penetrance and cancer patterns remain incompletely documented. We have analyzed international agency for research on cancer TP53 database to reevaluate age and variant-dependent tumor patterns. RECENT FINDINGS: Genome-wide studies suggest that germline variants are more frequent than estimated prevalence of Li-Fraumeni syndrome (LFS), suggesting that many carriers of potentially pathogenic mutations may not develop the syndrome. Carriers of a germline TP53 mutation who are detected in a clinical context have a penetrance of 80% at age 70. Penetrance varies according to age, sex and mutation type. Temporal tumor patterns show distinct phases, with childhood phase (0-15 years, 22% of all cancers) characterized by adrenal cortical carcinoma, choroid plexus carcinoma, rhabdomyosarcoma and medulloblastoma; early adulthood phase (16-50 years, 51%) including breast cancer, osteosarcoma, soft tissue sarcomas, leukemia, astrocytoma and glioblastoma, colorectal and lung cancer; late adulthood phase (51-80 years, 27%) including pancreatic and prostate cancer. SUMMARY: Germline pathogenic variants in TP53 gene have different consequences according to cell, tissue, context and age. The occurrence of frequent variants in patients with no criteria suggestive of LFS calls for attention in predicting individual risk and highlights the need of additional predictors for assigning carriers to appropriate surveillance programs.


Assuntos
Genes p53 , Mutação em Linhagem Germinativa , Síndrome de Li-Fraumeni/genética , Proteína Supressora de Tumor p53/genética , Animais , Humanos
12.
Proc Natl Acad Sci U S A ; 112(4): 982-5, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25583489

RESUMO

The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.4‰ and sulfur is (32)S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The (32)S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.


Assuntos
Carcinoma Hepatocelular/sangue , Cobre/sangue , Neoplasias Hepáticas/sangue , Enxofre/sangue , Microambiente Tumoral , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isótopos de Enxofre/sangue
13.
Hum Mutat ; 38(12): 1723-1730, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28861920

RESUMO

Li-Fraumeni syndrome (LFS) is an autosomal-dominant cancer predisposition disorder associated with pathogenic germline variants in TP53, with a high penetrance over an individual's lifetime. The actual population prevalence of pathogenic germline TP53 mutations is still unclear, most likely due to biased selection of cancer affected families. The aim of this study was to estimate the population prevalence of potentially pathogenic TP53 exonic variants in three sequencing databases, totaling 63,983 unrelated individuals. Potential pathogenicity was defined using an original algorithm combining bioinformatic prediction tools, suggested clinical significance, and functional data. We identified 34 different potentially pathogenic TP53 variants in 131 out of 63,983 individuals (0.2%). Twenty-eight (82%) of these variants fell within the DNA-binding domain of TP53, with an enrichment for specific variants that were not previously identified as LFS mutation hotspots, such as the p.R290H and p.N235S variants. Our findings reveal that the population prevalence of potentially pathogenic TP53 variants may be up to 10 times higher than previously estimated from family-based studies. These results point to the need for further studies aimed at evaluating cancer penetrance modifiers as well as the risk associated between cancer and rare TP53 variants.


Assuntos
Bases de Dados Genéticas , Exoma/genética , Variação Genética , Síndrome de Li-Fraumeni/genética , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Família , Feminino , Genótipo , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Penetrância , Prevalência , Sequenciamento do Exoma
14.
Cancer ; 123(21): 4207-4214, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28654149

RESUMO

BACKGROUND: Large epidemiologic studies have reported the premature onset of age-related conditions, such as ischemic heart disease and diabetes mellitus, in childhood cancer survivors, decades earlier than in their peers. The authors investigated whether young adult survivors of childhood acute lymphoblastic leukemia (ALL) have a biologic phenotype of cellular ageing and chronic inflammation. METHODS: Plasma inflammatory cytokines were measured using a cytometric bead array in 87 asymptomatic young adult survivors of childhood ALL (median age, 25 years; age range, 18-35 years) who attended annual follow-up clinic and compared with healthy, age-matched and sex-matched controls. Leukocyte telomere length (LTL) was measured using Southern blot analysis. RESULTS: Survivors had significant elevation of plasma interleukin-2 (IL-2), IL-10, IL-17a, and high-sensitivity C-reactive protein levels (all P < .05). A raised high-sensitivity C-reactive protein level (>0.8 mg/dL) was related to increased odds of having metabolic syndrome (odds ratio, 7.256; 95% confidence interval, 1.501-35.074). Survivors also had significantly shorter LTL compared with controls (median, 9866 vs 10,392 base pairs; P = .021). Compared with published data, LTL in survivors was similar to that in healthy individuals aged 20 years older. Survivors who received cranial irradiation had shorter LTL compared with those who had not (P = .013). CONCLUSIONS: Asymptomatic young adult survivors of childhood ALL demonstrate a biologic profile of chronic inflammation and telomere attrition, consistent with an early onset of cellular processes that drive accelerated aging. These processes may explain the premature development of age-related chronic conditions in childhood cancer survivors. Understanding their molecular basis may facilitate targeted interventions to disrupt the accelerated aging process and its long-term impact on overall health. Cancer 2017;123:4207-4214. © 2017 American Cancer Society.


Assuntos
Adultos Sobreviventes de Eventos Adversos na Infância , Proteína C-Reativa/análise , Senescência Celular , Inflamação/sangue , Interleucinas/sangue , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras , Encurtamento do Telômero , Adolescente , Adulto , Envelhecimento , Biomarcadores/sangue , Estudos de Casos e Controles , Doença Crônica , Irradiação Craniana/efeitos adversos , Feminino , Humanos , Interleucina-10/sangue , Interleucina-17/sangue , Interleucina-2/sangue , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Telômero/efeitos da radiação , Adulto Jovem
16.
Proc Natl Acad Sci U S A ; 111(43): 15497-501, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25313051

RESUMO

The Li-Fraumeni syndrome (LFS) and its variant form (LFL) is a familial predisposition to multiple forms of childhood, adolescent, and adult cancers associated with germ-line mutation in the TP53 tumor suppressor gene. Individual disparities in tumor patterns are compounded by acceleration of cancer onset with successive generations. It has been suggested that this apparent anticipation pattern may result from germ-line genomic instability in TP53 mutation carriers, causing increased DNA copy-number variations (CNVs) with successive generations. To address the genetic basis of phenotypic disparities of LFS/LFL, we performed whole-genome sequencing (WGS) of 13 subjects from two generations of an LFS kindred. Neither de novo CNV nor significant difference in total CNV was detected in relation with successive generations or with age at cancer onset. These observations were consistent with an experimental mouse model system showing that trp53 deficiency in the germ line of father or mother did not increase CNV occurrence in the offspring. On the other hand, individual records on 1,771 TP53 mutation carriers from 294 pedigrees were compiled to assess genetic anticipation patterns (International Agency for Research on Cancer TP53 database). No strictly defined anticipation pattern was observed. Rather, in multigeneration families, cancer onset was delayed in older compared with recent generations. These observations support an alternative model for apparent anticipation in which rare variants from noncarrier parents may attenuate constitutive resistance to tumorigenesis in the offspring of TP53 mutation carriers with late cancer onset.


Assuntos
Antecipação Genética , Heterogeneidade Genética , Predisposição Genética para Doença , Síndrome de Li-Fraumeni/genética , Neoplasias/genética , Adulto , Idade de Início , Animais , Criança , Segregação de Cromossomos/genética , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA/genética , Exoma/genética , Características da Família , Feminino , Genoma Humano/genética , Mutação em Linhagem Germinativa/genética , Heterozigoto , Humanos , Masculino , Camundongos Knockout , Pessoa de Meia-Idade , Linhagem , Fenótipo , Análise de Sequência de DNA , Proteína Supressora de Tumor p53/genética
18.
Genet Mol Biol ; 39(2): 210-22, 2016 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-27223485

RESUMO

In Brazil, breast cancer is a public health care problem due to its high incidence and mortality rates. In this study, we investigated the prevalence of hereditary breast cancer syndromes (HBCS) in a population-based cohort in Brazils southernmost capital, Porto Alegre. All participants answered a questionnaire about family history (FH) of breast, ovarian and colorectal cancer and those with a positive FH were invited for genetic cancer risk assessment (GCRA). If pedigree analysis was suggestive of HBCS, genetic testing of the BRCA1, BRCA2, TP53, and CHEK2 genes was offered. Of 902 women submitted to GCRA, 214 had pedigrees suggestive of HBCS. Fifty of them underwent genetic testing: 18 and 40 for BRCA1/BRCA2 and TP53 mutation screening, respectively, and 7 for CHEK2 1100delC testing. A deleterious BRCA2 mutation was identified in one of the HBOC probands and the CHEK2 1100delC mutation occurred in one of the HBCC families. No deleterious germline alterations were identified in BRCA1 or TP53. Although strict inclusion criteria and a comprehensive testing approach were used, the suspected genetic risk in these families remains unexplained. Further studies in a larger cohort are necessary to better understand the genetic component of hereditary breast cancer in Southern Brazil.

19.
Int J Cancer ; 136(1): 172-81, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24803312

RESUMO

Chronic Hepatitis B (HB) is the main risk factor for chronic liver disease (CLD) and hepatocellular carcinoma (HCC) in many low-resource countries, where diagnosis is constrained by lack of clinical, histopathological and biomarker resources. We have used proteomics to detect plasma biomarkers that outperform α-Fetoprotein (AFP), the most widely used biomarker for HCC diagnosis in low-resource contexts. Deep-plasma proteome analysis was performed in HCC patients, patients with CLD and in HB-carrier controls from Thailand (South-East Asia) and The Gambia (West-Africa). Mass spectrometry profiling identified latent-transforming growth factor ß binding-protein 2 (LTBP2) and Osteopontin (OPN) as being significantly elevated in HCC versus CLD and controls. These two proteins were further analyzed by ELISA in a total of 684 plasma samples, including 183 HCC, 274 CLD and 227 asymptomatic controls. When combined, LTBP2 and OPN showed an area under the receiver operating curve of 0.85 in distinguishing HCC from CLD in subjects with AFP <20 ng/mL. In a prospective cohort of 115 CLD patients from Korea, increased plasma levels of LTBP2 and/or OPN were detected in plasma collected over 2 years prior to diagnosis in 21 subjects who developed HCC. Thus, the combination of LTBP2 and OPN outperformed AFP for diagnosis and prediction of HCC and may therefore improve biomarker-based detection of HBV-related HCC.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/diagnóstico , Hepatite B Crônica/sangue , Proteínas de Ligação a TGF-beta Latente/sangue , Neoplasias Hepáticas/diagnóstico , Osteopontina/sangue , Área Sob a Curva , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/virologia , Estudos de Casos e Controles , Detecção Precoce de Câncer , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/virologia , Pobreza , Curva ROC
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