RESUMO
The abnormal vascular structures of hereditary hemorrhagic telangiectasia (HHT) often cause severe anemia due to recurrent hemorrhage, but HHT causal genes do not predict the severity of hematological complications. We tested for chance inheritance and clinical associations of rare deleterious variants in which loss-of-function causes bleeding or hemolytic disorders in the general population. In double-blinded analyses, all 104 patients with HHT from a single reference center recruited to the 100 000 Genomes Project were categorized on new MALO (more/as-expected/less/opposite) sub-phenotype severity scales, and whole genome sequencing data were tested for high impact variants in 75 HHT-independent genes encoding coagulation factors, or platelet, hemoglobin, erythrocyte enzyme, and erythrocyte membrane constituents. Rare variants (all gnomAD allele frequencies <0.003) were identified in 56 (75%) of these 75 HHT-unrelated genes. Deleteriousness assignments by Combined Annotation Dependent Depletion (CADD) scores >15 were supported by gene-level mutation significance cutoff scores. CADD >15 variants were identified in 38/104 (36.5%) patients with HHT, found for 1 in 10 patients within platelet genes; 1 in 8 within coagulation genes; and 1 in 4 within erythrocyte hemolytic genes. In blinded analyses, patients with greater hemorrhagic severity that had been attributed solely to HHT vessels had more CADD-deleterious variants in platelet (Spearman ρ = 0.25; P = .008) and coagulation (Spearman ρ = 0.21; P = .024) genes. However, the HHT cohort had 60% fewer deleterious variants in platelet and coagulation genes than expected (Mann-Whitney test P = .021). In conclusion, patients with HHT commonly have rare variants in genes of relevance to their phenotype, offering new therapeutic targets and opportunities for informed, personalized medicine strategies.
Assuntos
Telangiectasia Hemorrágica Hereditária , Receptores de Activinas Tipo II/genética , DNA , Variação Genética , Hemorragia , Humanos , Mutação , Fenótipo , Telangiectasia Hemorrágica Hereditária/complicações , Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/genética , Sequenciamento Completo do GenomaRESUMO
Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant multisystemic vascular dysplasia, characterized by arteriovenous malformations (AVMs), mucocutaneous telangiectasia and nosebleeds. HHT is caused by a heterozygous null allele in ACVRL1, ENG, or SMAD4, which encode proteins mediating bone morphogenetic protein (BMP) signaling. Several missense and stop-gain variants identified in GDF2 (encoding BMP9) have been reported to cause a vascular anomaly syndrome similar to HHT, however none of these patients met diagnostic criteria for HHT. HHT families from UK NHS Genomic Medicine Centres were recruited to the Genomics England 100,000 Genomes Project. Whole genome sequencing and tiering protocols identified a novel, heterozygous GDF2 sequence variant in all three affected members of one HHT family who had previously screened negative for ACVRL1, ENG, and SMAD4. All three had nosebleeds and typical HHT telangiectasia, and the proband also had severe pulmonary AVMs from childhood. In vitro studies showed the mutant construct expressed the proprotein but lacked active mature BMP9 dimer, suggesting the mutation disrupts correct cleavage of the protein. Plasma BMP9 levels in the patients were significantly lower than controls. In conclusion, we propose that this heterozygous GDF2 variant is a rare cause of HHT associated with pulmonary AVMs.
Assuntos
Malformações Arteriovenosas , Telangiectasia Hemorrágica Hereditária , Receptores de Activinas Tipo II/genética , Fístula Arteriovenosa , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/genética , Criança , Endoglina/genética , Endoglina/metabolismo , Epistaxe , Fator 2 de Diferenciação de Crescimento/genética , Humanos , Mutação , Artéria Pulmonar/anormalidades , Veias Pulmonares/anormalidades , Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/genética , Telangiectasia Hemorrágica Hereditária/patologiaRESUMO
Background: A significant increase in the incidence of papillary thyroid carcinoma (PTC) in subjects exposed to radiation at a young age is a well-documented health consequence of the Chernobyl accident. The ongoing Thyroid Ultrasound Examination (TUE) program in children and adolescents of Fukushima Prefecture in Japan also indicated a high prevalence of PTC although its attribution to radiation exposure is a subject of debate. The objective of this study was to perform histopathological analysis of tumor architecture and invasive properties in (i) radiogenic post-Chernobyl and sporadic PTCs from Ukraine, and (ii) PTCs in patients from Fukushima and other Prefectures of Japan of comparable age groups. Methods: The Ukrainian radiogenic PTCs included 245 PTCs from patients who resided in three highly 131I-contaminated regions and 165 sporadic PTCs diagnosed in residents of the same regions who were born after the accident and therefore not exposed to radioiodine. The Japanese series included 115 PTCs detected during the preliminary and the first full-scale surveys of the TUE in Fukushima and 223 PTCs from patients resident in other Prefectures. All of the subjects were included in the main statistical analysis. Three additional analyses were performed limiting the subjects to children, adolescents, and adults. Results: Ukrainian radiogenic PTC was characterized by the higher frequency of tumors with a dominant solid-trabecular growth pattern and higher invasiveness, more frequent extrathyroidal extension, lymphatic/vascular invasion, regional and distant metastases when compared with sporadic Ukrainian PTC. The integrative "invasiveness score," based on five cancer characteristics, was also higher in the radiogenic group. The differences were most pronounced in children. In contrast, no significant differences in tumor morphology or invasiveness were observed between the two Japanese groups or the three age subgroups. The only statistically significant findings were the higher proportion of male patients, smaller mean tumor size, and higher frequency of T1b tumors in the Fukushima group. Conclusions: The difference in morphological features that indicate biological behavior of PTC between the radiation-related and sporadic groups from Ukraine, together with the lack of such in the two groups from Japan, strongly suggest a nonradiogenic etiology of PTC from Fukushima and other Prefectures.
Assuntos
Acidente Nuclear de Chernobyl , Acidente Nuclear de Fukushima , Neoplasias Induzidas por Radiação/patologia , Exposição à Radiação/efeitos adversos , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Japão/epidemiologia , Masculino , Estadiamento de Neoplasias , Neoplasias Induzidas por Radiação/epidemiologia , Medição de Risco , Fatores de Risco , Câncer Papilífero da Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/epidemiologia , Fatores de Tempo , Ucrânia/epidemiologia , Adulto JovemRESUMO
Fresh-frozen tissue is the "gold standard" biospecimen type for next-generation sequencing (NGS). However, collecting frozen tissue is usually not feasible because clinical workflows deliver formalin-fixed, paraffin-embedded (FFPE) tissue blocks. Some clinicians and researchers are reticent to embrace the use of FFPE tissue for NGS because FFPE tissue can yield low quantities of degraded DNA, containing formalin-induced mutations. We describe the process by which formalin-induced deamination can lead to artifactual cytosine (C) to thymine (T) and guanine (G) to adenine (A) (C:G > T:A) mutation calls and perform a literature review of 17 publications that compare NGS data from patient-matched fresh-frozen and FFPE tissue blocks. We conclude that although it is indeed true that sequencing data from FFPE tissue can be poorer than those from frozen tissue, any differences occur at an inconsequential magnitude, and FFPE biospecimens can be used in genomic medicine with confidence.
Assuntos
Medicina Baseada em Evidências , Formaldeído , Genômica , Inclusão em Parafina , Fixação de Tecidos , Artefatos , DNA Glicosilases/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , MutaçãoRESUMO
DNA extracted from formalin-fixed, paraffin-embedded tissue sections is often inadequate for sequencing, due to poor yield or degradation. We optimized the proteinase K digest by testing increased volume of enzyme and increased digest length from the manufacturer's protocol using 54 biospecimens, performing the digest in centrifuge tubes. Doubling the quantity of proteinase K resulted in a median increase in yield of 96%. Applying the optimized proteinase K protocol to sections deparaffinized on microscope slides generated a further increase in yield of 41%, but only at >50,000 epithelial tumor cells/section. DNA yield now correlated with (χ2 = 0.84) and could be predicted from the epithelial tumor cell number. DNA integrity was assayed using end point multiplex PCR (amplicons of 100-400 bp visualized on a gel), quantitative PCR (qPCR; Illumina FFPE QC Assay), and nanoelectrophoresis (DNA Integrity Numbers [DINs]). Generally, increases in yield were accompanied by increases in integrity, but sometimes qPCR and DIN results were conflicting. Amplicons of 400 bp were almost universally obtained. The process of optimization enabled us to reduce the percentage of samples that failed published quality control thresholds for determining amenability to whole genome sequencing from 33% to 7%.
Assuntos
Extratos Celulares/química , DNA/análise , Endopeptidase K/metabolismo , Neoplasias/diagnóstico , Proteólise/efeitos dos fármacos , Sequência de Bases , Linhagem Celular Tumoral , Epitélio/química , Formaldeído/química , Perfilação da Expressão Gênica , Humanos , Inclusão em Parafina , Controle de Qualidade , Reação em Cadeia da Polimerase em Tempo Real , Fixação de TecidosAssuntos
Detecção Precoce de Câncer/normas , Agências Internacionais/normas , Neoplasias Induzidas por Radiação/epidemiologia , Exposição à Radiação/efeitos adversos , Liberação Nociva de Radioativos , Testes de Função Tireóidea/normas , Glândula Tireoide/efeitos da radiação , Neoplasias da Glândula Tireoide/epidemiologia , Consenso , Humanos , Neoplasias Induzidas por Radiação/diagnóstico , Vigilância da População , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Neoplasias da Glândula Tireoide/diagnóstico , Fatores de TempoRESUMO
It has long been known that the thyroid is a radiosensitive organ. It is the only organ in the body to both take up and bind iodine, and therefore exposure to radioiodine in fallout from nuclear power plants poses an increased danger to the thyroid. Studies following the Chernobyl accident have shown that children are most at risk from the development of thyroid cancer following exposure to radioactive iodine in fallout. This article reviews what we know so far about the type of thyroid cancer induced by radiation, its molecular biology and clinical outcome.
Assuntos
Radioisótopos do Iodo/efeitos adversos , Neoplasias Induzidas por Radiação/etiologia , Neoplasias da Glândula Tireoide/etiologia , HumanosRESUMO
BACKGROUND: The issue of whether radiation-induced thyroid cancer is pathologically different from sporadic remains not fully answered. This study compared structural characteristics and invasive features of papillary thyroid carcinoma (PTC) in two age-matched groups: patients who were children (≤4 years old) at the time of the Chernobyl accident and who lived in three regions of Ukraine most contaminated by radioactive iodine 131I ("radiogenic" cancer), and those who lived in the same regions but who were born after 1987 and were not exposed to 131I ("sporadic" cancer). Further, the histopathologic features of PTC were analyzed in relation to age and individual 131I thyroid dose. METHODS: The study included 301 radiogenic and 194 sporadic PTCs. According to age at surgery, patients were subdivided into children (≤14 years old), adolescents (15-18 years old), and adults (19-28 years old). Statistical analyses included univariate tests and multivariable logistic regression within and across the age subgroups. Analyses of morphological features related to 131I doses were conducted among exposed patients on categorical and continuous scales controlling for sex and age. RESULTS: Among children, radiogenic PTC displayed a significantly higher frequency of tumors with a dominant solid growth pattern, intrathyroidal spread, extrathyroidal extension, lymphatic/vascular invasion, and distant metastases. Exposed adolescents more frequently displayed extrathyroidal extension, lymphatic/vascular invasion, and distant metastases. Exposed adults more frequently had intrathyroidal spread and extrathyroidal extension. The frequency of PTC with dominant papillary pattern and oxyphilic cell metaplasia was significantly lower in radiogenic compared to sporadic tumors for all age groups. Manifestations of tumor aggressiveness were most frequent in children compared to adolescents and adults regardless of etiology. CONCLUSIONS: Radiogenic PTC is less likely to demonstrate a dominant papillary growth pattern and more likely to display more aggressive tumor behavior than sporadic PTC. Histopathologic tumor aggressiveness declines with patient age in both radiogenic and sporadic cases.
Assuntos
Carcinoma Papilar/patologia , Acidente Nuclear de Chernobyl , Neoplasias Induzidas por Radiação/patologia , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Ucrânia , Adulto JovemRESUMO
Exposure to ionizing radiation is ubiquitous, and it is well established that moderate and high doses cause ill-health and can be lethal. The health effects of low doses or low dose-rates of ionizing radiation are not so clear. This paper describes a project which sets out to summarize, as a restatement, the natural science evidence base concerning the human health effects of exposure to low-level ionizing radiation. A novel feature, compared to other reviews, is that a series of statements are listed and categorized according to the nature and strength of the evidence that underpins them. The purpose of this restatement is to provide a concise entrée into this vibrant field, pointing the interested reader deeper into the literature when more detail is needed. It is not our purpose to reach conclusions on whether the legal limits on radiation exposures are too high, too low or just right. Our aim is to provide an introduction so that non-specialist individuals in this area (be they policy-makers, disputers of policy, health professionals or students) have a straightforward place to start. The summary restatement of the evidence and an extensively annotated bibliography are provided as appendices in the electronic supplementary material.
Assuntos
Exposição à Radiação/efeitos adversos , Radiação Ionizante , HumanosRESUMO
BACKGROUND: The symposium entitled "Chernobyl +30, Fukushima +5: Lessons and Solutions for Fukushima's Thyroid Question" was held in September, 2016 in Fukushima. The aim of the Symposium was to revisit and recapitulate evidence from the studies in Chernobyl in order to share multidisciplinary opinions and views on the likely reason for the high rate of thyroid cancer detected by the Thyroid Ultrasound Examination program in Fukushima Prefecture. PARTICIPANTS AND MATTERS DISCUSSED: The high prevalence of thyroid cancer in young individuals causes concerns among Fukushima residents and the general public that it might be due to putative radiation exposure from the Fukushima Daiichi Nuclear Power Plant accident. Twenty-six experts from Japan and abroad, including participants affiliated with international organizations, reviewed the results of radiation epidemiology investigations in Chernobyl, presented clinical experience of diagnosis, treatment and follow-up of patients with radiation-related thyroid cancer, and scrutinized the findings on thyroid cancer in Fukushima. CONCLUSION: Conclusions drawn at the symposium included understanding that in contrast to Chernobyl, doses to the public from the accident in Fukushima were too low to give rise to a discernible excess risk for thyroid cancer. The high detection rate of thyroid cancer and benign abnormalities resulted from the use of highly sensitive ultrasound equipment and sophisticated protocol of examination used in the Thyroid Ultrasound Examination, and therefore not attributable to radiation. Coordinated efforts will be necessary to avoid overdiagnosis and overtreatment, which may carry its own health disbenefits. Clear communication to the screening participants and their families is recommended in regard to why the examination is being conducted and to explain the likely outcomes and risks, including the means and options for treatment if a thyroid disorder is detected.
Assuntos
Acidente Nuclear de Fukushima , Neoplasias da Glândula Tireoide , Acidente Nuclear de Chernobyl , Humanos , Japão/epidemiologia , Neoplasias Induzidas por Radiação/epidemiologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/etiologia , Ucrânia/epidemiologia , UltrassonografiaRESUMO
BACKGROUND: The 70-gene signature test (MammaPrint) has been shown to improve prediction of clinical outcome in women with early-stage breast cancer. We sought to provide prospective evidence of the clinical utility of the addition of the 70-gene signature to standard clinical-pathological criteria in selecting patients for adjuvant chemotherapy. METHODS: In this randomized, phase 3 study, we enrolled 6693 women with early-stage breast cancer and determined their genomic risk (using the 70-gene signature) and their clinical risk (using a modified version of Adjuvant! Online). Women at low clinical and genomic risk did not receive chemotherapy, whereas those at high clinical and genomic risk did receive such therapy. In patients with discordant risk results, either the genomic risk or the clinical risk was used to determine the use of chemotherapy. The primary goal was to assess whether, among patients with high-risk clinical features and a low-risk gene-expression profile who did not receive chemotherapy, the lower boundary of the 95% confidence interval for the rate of 5-year survival without distant metastasis would be 92% (i.e., the noninferiority boundary) or higher. RESULTS: A total of 1550 patients (23.2%) were deemed to be at high clinical risk and low genomic risk. At 5 years, the rate of survival without distant metastasis in this group was 94.7% (95% confidence interval, 92.5 to 96.2) among those not receiving chemotherapy. The absolute difference in this survival rate between these patients and those who received chemotherapy was 1.5 percentage points, with the rate being lower without chemotherapy. Similar rates of survival without distant metastasis were reported in the subgroup of patients who had estrogen-receptor-positive, human epidermal growth factor receptor 2-negative, and either node-negative or node-positive disease. CONCLUSIONS: Among women with early-stage breast cancer who were at high clinical risk and low genomic risk for recurrence, the receipt of no chemotherapy on the basis of the 70-gene signature led to a 5-year rate of survival without distant metastasis that was 1.5 percentage points lower than the rate with chemotherapy. Given these findings, approximately 46% of women with breast cancer who are at high clinical risk might not require chemotherapy. (Funded by the European Commission Sixth Framework Program and others; ClinicalTrials.gov number, NCT00433589; EudraCT number, 2005-002625-31.).
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/genética , Quimioterapia Adjuvante , Perfilação da Expressão Gênica , Predisposição Genética para Doença , Metástase Neoplásica/prevenção & controle , Adulto , Idoso , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/cirurgia , Intervalo Livre de Doença , Feminino , Expressão Gênica , Testes Genéticos , Humanos , Estimativa de Kaplan-Meier , Mastectomia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Estudos Prospectivos , Risco , Medição de RiscoRESUMO
OBJECTIVES: To evaluate the PAXgene tissue fixation system. METHODS: Clinical biospecimens (n = 46) were divided into PAXgene-fixed paraffin-embedded (PFPE), formalin-fixed paraffin-embedded (FFPE), and fresh-frozen (FF) blocks. PFPE and FFPE sections were compared for histology (H&E staining) and immunohistochemistry (14 antibodies) using tissue microarrays. PFPE, FFPE, and FF samples were compared in terms of RNA quality (RNA integrity number, polymerase chain reaction [PCR] amplicon length, and quantitative reverse transcription PCR), DNA quality (gel electrophoresis and methylation profiling) and protein quality (liquid chromatography-mass spectrometry [LC-MS/MS]). RESULTS: PFPE protocol optimization was required in most cases and is described. RNA extracted from PFPE sections was considerably less degraded than that from FFPE sections but more degraded than that from FF blocks. Genomic-length DNA was extracted from PFPE and FF biospecimens, and methylation profiling showed PFPE and FF biospecimens to be almost indistinguishable. Only degraded DNA was extracted from FFPE biospecimens. PFPE sections yielded peptides that were slightly less amenable to LC-MS/MS analysis than FFPE sections, but FF gave slightly better results. CONCLUSIONS: While it cannot be envisaged that PAXgene will replace formalin in a routine clinical setting, for specific projects or immunodiagnostics involving biospecimens destined for immunohistochemical or histologic staining and DNA or RNA analyses, PAXgene is a viable option.
Assuntos
Perfilação da Expressão Gênica/métodos , Fixação de Tecidos/métodos , Ácido Acético , Adulto , Idoso , Carcinoma/diagnóstico , Neoplasias do Colo/diagnóstico , Etanol , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/diagnóstico , Masculino , Metanol , Pessoa de Meia-Idade , Inclusão em Parafina , Reação em Cadeia da Polimerase , Proteômica/métodos , Aspergilose Pulmonar/diagnóstico , Análise Serial de TecidosRESUMO
BACKGROUND: The Ovarian Protection Trial In Premenopausal Breast Cancer Patients "OPTION" trial (NCT00427245) was a prospective, multicenter, randomised, open label study evaluating the frequency of primary ovarian insufficiency (POI) at 12 months in women randomised to 6-8 cycles of (neo)adjuvant chemotherapy (CT) +/- goserelin (G). Here we report the results of a secondary endpoint analysis of the effects of CT+/-G on markers of bone turnover. METHODS: Serum for bone alkaline phosphatase (BALP) and urine for N-terminal telopeptide (NTX) were collected at baseline, 6, 12, 18, 24 and 36 months. Changes in median levels of bone turnover markers were evaluated for the overall population, according to age stratification at randomisation (≤40 vs >40 years) and with exploratory analysis according to POI rates at 12 months. RESULTS: In the overall population, there was a significant increase in NTX at 6 months compared to baseline in patients treated with CT+G (40.81 vs 57.82 p=0.0074) with normalisation of levels thereafter. BALP was significantly increased compared to baseline at 6 months and 12 months in those receiving CT+G, but normalised thereafter. BALP remained significantly higher compared to baseline at 12, 24 and 36 months in patients receiving CT, resulting in a significant difference between treatment groups at 36 months (CT+G 5.845 vs CT 8.5 p=0.0006). These changes were predominantly seen in women >40 years. Women with POI at 12 months showed altered bone formation compared to baseline levels for a longer duration than women who maintained menses. CONCLUSION: Addition of G to CT increases bone turnover during treatment with normalisation after cessation of treatment suggesting G may offer sufficient ovarian protection against CT induced POI to negate longstanding altered bone turnover associated with POI.
RESUMO
PURPOSE: Following the nuclear accidents in Chernobyl and later in Fukushima, the nuclear community has been faced with important issues concerning how to search for and diagnose biological consequences of low-dose internal radiation contamination. Although after the Chernobyl accident an increase in childhood papillary thyroid cancer (PTC) was observed, it is still not clear whether the molecular biology of PTCs associated with low-dose radiation exposure differs from that of sporadic PTC. METHODS: We investigated tissue samples from 65 children/young adults with PTC using DNA microarray (Affymetrix, Human Genome U133 2.0 Plus) with the aim of identifying molecular differences between radiation-induced (exposed to Chernobyl radiation, ECR) and sporadic PTC. All participants were resident in the same region so that confounding factors related to genetics or environment were minimized. RESULTS: There were small but significant differences in the gene expression profiles between ECR and non-ECR PTC (global test, p < 0.01), with 300 differently expressed probe sets (p < 0.001) corresponding to 239 genes. Multifactorial analysis of variance showed that besides radiation exposure history, the BRAF mutation exhibited independent effects on the PTC expression profile; the histological subset and patient age at diagnosis had negligible effects. Ten genes (PPME1, HDAC11, SOCS7, CIC, THRA, ERBB2, PPP1R9A, HDGF, RAD51AP1, and CDK1) from the 19 investigated with quantitative RT-PCR were confirmed as being associated with radiation exposure in an independent, validation set of samples. CONCLUSION: Significant, but subtle, differences in gene expression in the post-Chernobyl PTC are associated with previous low-dose radiation exposure.
Assuntos
Carcinoma/etiologia , Carcinoma/genética , Perfilação da Expressão Gênica , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/genética , Liberação Nociva de Radioativos , Neoplasias da Glândula Tireoide/etiologia , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Carcinoma Papilar , Criança , Pré-Escolar , Éxons/genética , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Câncer Papilífero da Tireoide , Adulto JovemRESUMO
Exposure to ionizing radiation during childhood markedly increases the risk of developing papillary thyroid cancer. We examined tissues from 26 Ukrainian patients with thyroid cancer who were younger than 10 years of age and living in contaminated areas during the time of the Chernobyl nuclear reactor accident. We identified nonoverlapping somatic driver mutations in all 26 cases through candidate gene assays and next-generation RNA sequencing. We found that 22 tumors harbored fusion oncogenes that arose primarily through intrachromosomal rearrangements. Altogether, 23 of the oncogenic drivers identified in this cohort aberrantly activate MAPK signaling, including the 2 somatic rearrangements resulting in fusion of transcription factor ETS variant 6 (ETV6) with neurotrophic tyrosine kinase receptor, type 3 (NTRK3) and fusion of acylglycerol kinase (AGK) with BRAF. Two other tumors harbored distinct fusions leading to overexpression of the nuclear receptor PPARγ. Fusion oncogenes were less prevalent in tumors from a cohort of children with pediatric thyroid cancers that had not been exposed to radiation but were from the same geographical regions. Radiation-induced thyroid cancers provide a paradigm of tumorigenesis driven by fusion oncogenes that activate MAPK signaling or, less frequently, a PPARγ-driven transcriptional program.
Assuntos
Carcinoma/genética , Acidente Nuclear de Chernobyl , Mutação , Neoplasias Induzidas por Radiação/genética , Fusão Oncogênica , Neoplasias da Glândula Tireoide/genética , Adolescente , Animais , Sequência de Bases , Carcinoma Papilar , Criança , Pré-Escolar , Estudos de Coortes , DNA de Neoplasias/genética , Feminino , Rearranjo Gênico , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos , Dados de Sequência Molecular , Células NIH 3T3 , PPAR gama/genética , Fosfatidilinositol 3-Quinases/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Proto-Oncogênicas c-ret/genética , Receptor trkC/genética , Receptores da Tireotropina/genética , Proteínas Repressoras/genética , Câncer Papilífero da Tireoide , Ucrânia , Adulto Jovem , Variante 6 da Proteína do Fator de Translocação ETSRESUMO
The only unequivocal radiological effect of the Chernobyl accident on human health is the increase in thyroid cancer in those exposed in childhood or early adolescence. In response to the scientific interest in studying the molecular biology of thyroid cancer post Chernobyl, the Chernobyl Tissue Bank (CTB: www.chernobyltissuebank.com) was established in 1998. Thus far it is has collected biological samples from 3,861 individuals, and provided 27 research projects with 11,254 samples. The CTB was designed from its outset as a resource to promote the integration of research and clinical data to facilitate a systems biology approach to radiation related thyroid cancer. The project has therefore developed as a multidisciplinary collaboration between clinicians, dosimetrists, molecular biologists and bioinformaticians and serves as a paradigm for tissue banking in the omics era.
RESUMO
The future success of translational research is critically dependent on the procurement and availability of high-quality tissue specimens linked to accurate histopathologic and clinical information about the individual banked specimen. The international community has awakened to this critical need only recently. Three major roadblocks have hindered the success of previous biobank consortiums: (1) Ethical issues surrounding patient consent and ownership of intellectual property, (2) Failure to properly preserve the molecular content of the tissue, and failure to reliably document clinical data linked to the specimen, and (3) Management issues: inadequate funding, competition for use of the tissue, inadequate personnel and facilities, and absence of dedicated database software. This chapter reviews these critical roadblocks and discusses international efforts to provide strategies to implement high-quality biobanks.
Assuntos
Bancos de Espécimes Biológicos , Neoplasias , Bancos de Espécimes Biológicos/ética , Bancos de Espécimes Biológicos/legislação & jurisprudência , Bancos de Espécimes Biológicos/organização & administração , Pesquisa Biomédica , Bases de Dados Factuais , Humanos , Controle de QualidadeAssuntos
Acidente Nuclear de Chernobyl , Neoplasias Induzidas por Radiação/etiologia , Lesões por Radiação/etiologia , Liberação Nociva de Radioativos , Humanos , Japão/epidemiologia , Neoplasias Induzidas por Radiação/mortalidade , Guerra Nuclear , Doses de Radiação , Lesões por Radiação/mortalidade , Risco , Ucrânia/epidemiologiaRESUMO
Structural genomic rearrangements are frequent findings in human cancers. Therefore, papillary thyroid carcinomas (PTCs) were investigated for chromosomal aberrations and rearrangements of the RET proto-oncogene. For this purpose, primary cultures from 23 PTC have been established and metaphase preparations were analysed by spectral karyotyping (SKY). In addition, interphase cell preparations of the same cases were investigated by fluorescence in situ hybridisation (FISH) for the presence of RET/PTC rearrangements using RET-specific DNA probes. SKY analysis of PTC revealed structural aberrations of chromosome 11 and several numerical aberrations with frequent loss of chromosomes 20, 21, and 22. FISH analysis for RET/PTC rearrangements showed prevalence of this rearrangement in 72% (16 out of 22) of cases. However, only subpopulations of tumour cells exhibited this rearrangement indicating genetic heterogeneity. The comparison of visual and automated scoring of FISH signals revealed concordant results in 19 out of 22 cases (87%) indicating reliable scoring results using the optimised scoring parameter for RET/PTC with the automated Metafer4 system. It can be concluded from this study that genomic rearrangements are frequent in PTC and therefore important events in thyroid carcinogenesis.
Assuntos
Acidente Nuclear de Chernobyl , Aberrações Cromossômicas , Rearranjo Gênico , Neoplasias Induzidas por Radiação/genética , Adolescente , Adulto , Carcinoma , Carcinoma Papilar , Distribuição de Qui-Quadrado , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Hibridização in Situ Fluorescente , Masculino , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-ret/genética , Cariotipagem Espectral , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/genética , Células Tumorais CultivadasRESUMO
Delivering the promise of personalised medicine is the challenge that the current generation of scientists face. The variations in human physiology and disease are considerable, and designing appropriate strategies to deliver what has been promised will require access to tissue from a large number of volunteers. The NHS provides an ideal infrastructure for sample acquisition, but requires two things to make this available-public consent and support for extra manpower and administration. There is a disconnection between the NHS and tissue based research that needs to be addressed on a number of levels to provide a translational platform. This should enable the path to be beaten to provide the ideal tailored treatment for future patients; one that preserves quality of life by curing the disease with minimal side effects.