Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Mod Pathol ; 37(4): 100452, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38369186

RESUMO

The molecular characterization of male breast cancer (MaBC) has received limited attention in research, mostly because of its low incidence rate, accounting for only 0.5% to 1% of all reported cases of breast cancer each year. Managing MaBC presents significant challenges, with most treatment protocols being adapted from those developed for female breast cancer. Utilizing whole-genome sequencing (WGS) and state-of-the-art analyses, the genomic features of 10 MaBC cases (n = 10) were delineated and correlated with clinical and histopathologic characteristics. Using fluorescence in situ hybridization, an additional cohort of 18 patients was interrogated to supplement WGS findings. The genomic landscape of MaBC uncovered significant genetic alterations that could influence diagnosis and treatment. We found common somatic mutations in key driver genes, such as FAT1, GATA3, SMARCA4, and ARID2. Our study also mapped out structural variants that impact cancer-associated genes, such as ARID1A, ESR1, GATA3, NTRK1, and NF1. Using a WGS-based classifier, homologous recombination deficiency (HRD) was identified in 2 cases, both presenting with deleterious variants in BRCA2. Noteworthy was the observation of FGFR1 amplification in 21% of cases. Altogether, we identified at least 1 potential therapeutic target in 8 of the 10 cases, including high tumor mutational burden, FGFR1 amplification, and HRD. Our study is the first WGS characterization of MaBC, which uncovered potentially relevant variants, including structural events in cancer genes, HRD signatures, and germline pathogenic mutations. Our results demonstrate unique genetic markers and potential treatment targets in MaBC, thereby underlining the necessity of tailoring treatment strategies for this understudied patient population. These WGS-based findings add to the growing knowledge of MaBC genomics and highlight the need to expand research on this type of cancer.


Assuntos
Neoplasias da Mama Masculina , Neoplasias da Mama , Humanos , Masculino , Feminino , Neoplasias da Mama Masculina/genética , Neoplasias da Mama Masculina/terapia , Hibridização in Situ Fluorescente , Mutação , Neoplasias da Mama/patologia , Oncogenes , Mutação em Linhagem Germinativa , DNA Helicases/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética
2.
Am J Surg Pathol ; 48(2): 183-193, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38047392

RESUMO

Several reports describing a rare primary liver tumor with histologic features reminiscent of follicular thyroid neoplasms have been published under a variety of descriptive terms including thyroid-like, solid tubulocystic, and cholangioblastic cholangiocarcinoma. Although these tumors are considered to represent histologic variants, they lack classic features of cholangiocarcinoma and have unique characteristics, namely immunoreactivity for inhibin and NIPBL::NACC1 fusions. The purpose of this study is to present clinicopathologic and molecular data for a large series of these tumors to better understand their pathogenesis. We identified 11 hepatic tumors with these features. Immunohistochemical and NACC1 and NIPBL fluorescence in situ hybridization assays were performed on all cases. Four cases had available material for whole-genome sequencing (WGS) analysis. Most patients were adult women (mean age: 42 y) who presented with abdominal pain and large hepatic masses (mean size: 14 cm). Ten patients had no known liver disease. Of the patients with follow-up information, 3/9 (33%) pursued aggressive behavior. All tumors were composed of bland cuboidal cells with follicular and solid/trabecular growth patterns in various combinations, were immunoreactive for inhibin, showed albumin mRNA by in situ hybridization, and harbored the NIPBL::NACC1 fusion by fluorescence in situ hybridization. WGS corroborated the presence of the fusion in all 4 tested cases, high tumor mutational burden in 2 cases, and over 30 structural variants per case in 3 sequenced tumors. The cases lacked mutations typical of conventional intrahepatic cholangiocarcinoma. In this report, we describe the largest series of primary inhibin-positive hepatic neoplasms harboring a NIPBL::NACC1 fusion and the first WGS analysis of these tumors. We propose to name this neoplasm NIPBL:NACC1 fusion hepatic carcinoma.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Adulto , Humanos , Feminino , Hibridização in Situ Fluorescente , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Neoplasias Hepáticas/patologia , Ductos Biliares Intra-Hepáticos/patologia , Neoplasias dos Ductos Biliares/patologia , Inibinas , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/análise , Proteínas de Ciclo Celular/genética , Proteínas de Neoplasias/genética , Proteínas Repressoras/genética
4.
Nat Genet ; 55(6): 1022-1033, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37169874

RESUMO

Patients with high-risk neuroblastoma generally present with widely metastatic disease and often relapse despite intensive therapy. As most studies to date focused on diagnosis-relapse pairs, our understanding of the genetic and clonal dynamics of metastatic spread and disease progression remain limited. Here, using genomic profiling of 470 sequential and spatially separated samples from 283 patients, we characterize subtype-specific genetic evolutionary trajectories from diagnosis through progression and end-stage metastatic disease. Clonal tracing timed disease initiation to embryogenesis. Continuous acquisition of structural variants at disease-defining loci (MYCN, TERT, MDM2-CDK4) followed by convergent evolution of mutations targeting shared pathways emerged as the predominant feature of progression. At diagnosis metastatic clones were already established at distant sites where they could stay dormant, only to cause relapses years later and spread via metastasis-to-metastasis and polyclonal seeding after therapy.


Assuntos
Recidiva Local de Neoplasia , Neuroblastoma , Humanos , Recidiva Local de Neoplasia/genética , Neuroblastoma/genética , Evolução Clonal , Mutação , Metástase Neoplásica
5.
Blood Adv ; 7(15): 3862-3873, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-36867579

RESUMO

Genomic profiling during the diagnosis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in adults is used to guide disease classification, risk stratification, and treatment decisions. Patients for whom diagnostic screening fails to identify disease-defining or risk-stratifying lesions are classified as having B-other ALL. We screened a cohort of 652 BCP-ALL cases enrolled in UKALL14 to identify and perform whole genome sequencing (WGS) of paired tumor-normal samples. For 52 patients with B-other, we compared the WGS findings with data from clinical and research cytogenetics. WGS identified a cancer-associated event in 51 of 52 patients, including an established subtype defining genetic alterations that were previously missed with standard-of-care (SoC) genetics in 5 of them. Of the 47 true B-other ALL, we identified a recurrent driver in 87% (41). A complex karyotype via cytogenetics emerges as a heterogeneous group, including distinct genetic alterations associated with either favorable (DUX4-r) or poor outcomes (MEF2D-r and IGK::BCL2). For a subset of 31 cases, we integrated the findings from RNA sequencing (RNA-seq) analysis to include fusion gene detection and classification based on gene expression. Compared with RNA-seq, WGS was sufficient to detect and resolve recurrent genetic subtypes; however, RNA-seq can provide orthogonal validation of findings. In conclusion, we demonstrated that WGS can identify clinically relevant genetic abnormalities missed with SoC testing as well as identify leukemia driver events in virtually all cases of B-other ALL.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Adulto , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Mutação , Sequenciamento Completo do Genoma , Cariótipo Anormal
6.
Biology (Basel) ; 11(11)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36421365

RESUMO

In addition to representing a significant part of the natural background radiation exposure, α-particles are thought to be a powerful tool for targeted radiotherapy treatments. Understanding the molecular mechanisms of recognition, signaling, and repair of α-particle-induced DNA damage is not only important in assessing the risk associated with human exposure, but can also potentially help in identifying ways of improving the efficacy of radiation treatment. α-particles (He2+ ions), as well as other types of ionizing radiation, and can cause a wide variety of DNA lesions, including DNA double-strand breaks (DSBs). In mammalian cells, DNA DSBs can be repaired by two major pathways: non-homologous end-joining (NHEJ) and homologous recombination (HR). Here, we investigated their dynamics in mouse NIH-3T3 cells through the recruitment of key proteins, such as the KU heterodimer for NHEJ and RAD51 for HR upon localized α-particle irradiation. To deliver α-particles, we used the MIRCOM microbeam, which allows targeting of subnuclear structures with submicron accuracy. Using mouse NIH-3T3 cells, we found that the KU heterodimer is recruited much earlier at DNA damage sites marked by H2AX phosphorylation than RAD51. We also observed that the difference in the response of the KU complex and RAD51 is not only in terms of time, but also in function of the chromatin nature. The use of a microbeam such as MIRCOM, represents a powerful tool to study more precisely the cellular response to ionizing irradiation in a spatiotemporal fashion at the molecular level.

7.
Leuk Res ; 117: 106857, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35598475

RESUMO

Data concerning the treatment approach and clinical outcomes in younger patients with myelodysplastic syndromes (MDS) are lacking. Furthermore, published results from genomic profiling in the young adult MDS population are few. We identified patients aged 20-50 at diagnosis evaluated for de novo MDS at our institution over a 32-year period. Clinical information and results from sequencing panels were extracted for analysis. 68 eligible patients were found, including 32% with multilineage dysplasia and 29% with excess blasts-2 WHO subtypes. Revised International Prognostic Scoring System for MDS (IPSS-R) categorization had 47% high/very high-risk, and this classification held prognostic significance. The median overall survival was 59 months, and most patients (75%) underwent allogeneic hematopoietic cell transplantation (alloHCT). Thirty-four patients had mutational profiling; the most commonly mutated gene was TP53 and most commonly altered gene category was epigenetic regulators. Younger patients with de novo MDS represented a unique subset with high-risk disease features (adverse cytogenetics, higher R-IPSS) frequently observed along with alterations in TP53 and genes related to epigenetic and transcription pathways.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Síndromes Mielodisplásicas , Adulto , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Pessoa de Meia-Idade , Mutação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/terapia , Prognóstico , Fatores de Risco , Adulto Jovem
8.
Clin Cancer Res ; 28(8): 1614-1627, 2022 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-35078859

RESUMO

PURPOSE: Therapy-related myelodysplastic syndrome and acute leukemias (t-MDS/AL) are a major cause of nonrelapse mortality among pediatric cancer survivors. Although the presence of clonal hematopoiesis (CH) in adult patients at cancer diagnosis has been implicated in t-MDS/AL, there is limited published literature describing t-MDS/AL development in children. EXPERIMENTAL DESIGN: We performed molecular characterization of 199 serial bone marrow samples from 52 patients treated for high-risk neuroblastoma, including 17 with t-MDS/AL (transformation), 14 with transient cytogenetic abnormalities (transient), and 21 without t-MDS/AL or cytogenetic alterations (neuroblastoma-treated control). We also evaluated for CH in a cohort of 657 pediatric patients with solid tumor. RESULTS: We detected at least one disease-defining alteration in all cases at t-MDS/AL diagnosis, most commonly TP53 mutations and KMT2A rearrangements, including involving two novel partner genes (PRDM10 and DDX6). Backtracking studies identified at least one t-MDS/AL-associated mutation in 13 of 17 patients at a median of 15 months before t-MDS/AL diagnosis (range, 1.3-32.4). In comparison, acquired mutations were infrequent in the transient and control groups (4/14 and 1/21, respectively). The relative risk for development of t-MDS/AL in the presence of an oncogenic mutation was 8.8 for transformation patients compared with transient. Unlike CH in adult oncology patients, TP53 mutations were only detectable after initiation of cancer therapy. Last, only 1% of pediatric patients with solid tumor evaluated had CH involving myeloid genes. CONCLUSIONS: These findings demonstrate the clinical relevance of identifying molecular abnormalities in predicting development of t-MDS/AL and should guide the formation of intervention protocols to prevent this complication in high-risk pediatric patients.


Assuntos
Sobreviventes de Câncer , Leucemia Mieloide Aguda , Neuroblastoma , Adulto , Medula Óssea/patologia , Criança , Células Clonais , Humanos , Leucemia Mieloide Aguda/genética , Neuroblastoma/patologia
9.
NEJM Evid ; 1(7): EVIDoa2200008, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38319256

RESUMO

BACKGROUND: Risk stratification and therapeutic decision-making for myelodysplastic syndromes (MDS) are based on the International Prognostic Scoring System­Revised (IPSS-R), which considers hematologic parameters and cytogenetic abnormalities. Somatic gene mutations are not yet used in the risk stratification of patients with MDS. METHODS: To develop a clinical-molecular prognostic model (IPSS-Molecular [IPSS-M]), pretreatment diagnostic or peridiagnostic samples from 2957 patients with MDS were profiled for mutations in 152 genes. Clinical and molecular variables were evaluated for associations with leukemia-free survival, leukemic transformation, and overall survival. Feature selection was applied to determine the set of independent IPSS-M prognostic variables. The relative weights of the selected variables were estimated using a robust Cox multivariable model adjusted for confounders. The IPSS-M was validated in an external cohort of 754 Japanese patients with MDS. RESULTS: We mapped at least one oncogenic genomic alteration in 94% of patients with MDS. Multivariable analysis identified TP53multihit, FLT3 mutations, and MLLPTD as top genetic predictors of adverse outcomes. Conversely, SF3B1 mutations were associated with favorable outcomes, but this was modulated by patterns of comutation. Using hematologic parameters, cytogenetic abnormalities, and somatic mutations of 31 genes, the IPSS-M resulted in a unique risk score for individual patients. We further derived six IPSS-M risk categories with prognostic differences. Compared with the IPSS-R, the IPSS-M improved prognostic discrimination across all clinical end points and restratified 46% of patients. The IPSS-M was applicable in primary and secondary/therapy-related MDS. To simplify clinical use of the IPSS-M, we developed an open-access Web calculator that accounts for missing values. CONCLUSIONS: Combining genomic profiling with hematologic and cytogenetic parameters, the IPSS-M improves the risk stratification of patients with MDS and represents a valuable tool for clinical decision-making. (Funded by Celgene Corporation through the MDS Foundation, the Josie Robertson Investigators Program, the Edward P. Evans Foundation, the Projects of National Relevance of the Italian Ministry of University and Research, Associazione Italiana per la Ricerca sul Cancro, the Japan Agency for Medical Research and Development, Cancer Research UK, the Austrian Science Fund, the MEXT [Japanese Ministry of Education, Culture, Sports, Science and Technology] Program for Promoting Research on the Supercomputer Fugaku, the Japan Society for the Promotion of Science, the Taiwan Department of Health, and Celgene Corporation through the MDS Foundation.)

10.
Clin Cancer Res ; 27(14): 4003-4011, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34103301

RESUMO

PURPOSE: Biomarkers of response and resistance to FLT3 tyrosine kinase inhibitors (TKI) are still emerging, and optimal clinical combinations remain unclear. The purpose of this study is to identify co-occurring mutations that influence clinical response to the novel FLT3 inhibitor pexidartinib (PLX3397). EXPERIMENTAL DESIGN: We performed targeted sequencing of pretreatment blasts from 29 patients with FLT3 internal tandem duplication (ITD) mutations treated on the phase I/II trial of pexidartinib in relapsed/refractory FLT3-ITD+ acute myeloid leukemia (AML). We sequenced 37 samples from 29 patients with available material, including 8 responders and 21 non-responders treated at or above the recommended phase II dose of 3,000 mg. RESULTS: Consistent with other studies, we identified mutations in NRAS, TP53, IDH2, and a variety of epigenetic and transcriptional regulators only in non-responders. Among the most frequently mutated genes in non-responders was Cyclin D3 (CCND3). A total of 3 individual mutations in CCND3 (Q276*, S264R, and T283A) were identified in 2 of 21 non-responders (one patient had both Q276* and S264R). No CCND3 mutations were found in pexidartinib responders. Expression of the Q276* and T283A mutations in FLT3-ITD MV4;11 cells conferred resistance to apoptosis, decreased cell-cycle arrest, and increased proliferation in the presence of pexidartinib and other FLT3 inhibitors. Inhibition of CDK4/6 activity in CCND3 mutant MV4;11 cells restored pexidartinib-induced cell-cycle arrest but not apoptosis. CONCLUSIONS: Mutations in CCND3, a gene not commonly mutated in AML, are a novel cause of clinical primary resistance to FLT3 inhibitors in AML and may have sensitivity to CDK4/6 inhibition.


Assuntos
Aminopiridinas/uso terapêutico , Ciclina D3/genética , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Pirróis/uso terapêutico , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Linhagem Celular Tumoral , Humanos
11.
Int J Radiat Biol ; 97(9): 1181-1198, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34138666

RESUMO

PURPOSE: Biological and/or physical assays for retrospective dosimetry are valuable tools to recover the exposure situation and to aid medical decision making. To further validate and improve such biological and physical assays, in 2019, EURADOS Working Group 10 and RENEB performed a field exercise in Lund, Sweden, to simulate various real-life exposure scenarios. MATERIALS AND METHODS: For the dicentric chromosome assay (DCA), blood tubes were located at anthropomorphic phantoms positioned in different geometries and were irradiated with a 1.36 TBq 192Ir-source. For each exposure condition, dose estimates were provided by at least one laboratory and for four conditions by 17 participating RENEB laboratories. Three radio-photoluminescence glass dosimeters were placed at each tube to assess reference doses. RESULTS: The DCA results were homogeneous between participants and matched well with the reference doses (≥95% of estimates within ±0.5 Gy of the reference). For samples close to the source systematic underestimation could be corrected by accounting for exposure time. Heterogeneity within and between tubes was detected for reference doses as well as for DCA doses estimates. CONCLUSIONS: The participants were able to successfully estimate the doses and to provide important information on the exposure scenarios under conditions closely resembling a real-life situation.


Assuntos
Cromossomos Humanos/genética , Cromossomos Humanos/efeitos da radiação , Radiometria , Aberrações Cromossômicas/efeitos da radiação , Humanos , Exposição à Radiação/análise , Estudos Retrospectivos
13.
Cir Cir ; 89(3): 384-389, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34037621

RESUMO

OBJETIVO: Comparar los desenlaces entre la apendicectomía por laparoscopia por puerto único y multipuerto, y establecer si existe diferencia en el riesgo de colección intraabdominal posoperatoria. MÉTODO: Se realizó un estudio retrospectivo, observacional, mediante 116 historias clínicas de pacientes llevados a apendicectomía laparoscópica por único puerto y multipuerto en dos centros médicos. RESULTADOS: Desarrollaron colección intraabdominal 12 (10.3%) pacientes. No se encontraron diferencias entre ambas técnicas en cuanto al desarrollo de colección intraabdominal (p = 0.242), no hubo diferencia entre ambas técnicas en cuanto a sangrado intraoperatorio (p = 0.012) y el tiempo quirúrgico fue mayor en el grupo de puerto único (17.4 minutos en promedio). El 62.5% de los pacientes con sangrado > 50 ml desarrollaron colección intraabdominal. CONCLUSIONES: No se evidenció superioridad de ninguna de las dos intervenciones en apendicitis complicada, pero sí se confirma que la apendicectomía laparoscópica por puerto único es un procedimiento seguro, factible, no inferior y con tasas similares de complicaciones en comparación con la técnica convencional de apendicectomía laparoscópica. OBJECTIVE: To compare the decreases between the appendectomy by single port vs. multiport laparoscopy and to establish if there is a difference in the risk of postoperative intra-abdominal collection. METHOD: Retrospective study was carried out using 116 medical records of patients undergoing laparoscopic appendectomy through a single port and multiport in two medical centers. RESULTS: 12 (10.3%) patients developed an abdominal collection. No differences were found between the two techniques in terms of intra-abdominal collection development (p = 0.242), there was no difference between the two techniques in terms of intraoperative bleeding (p = 0.012), the surgical time was greater in the single-port group (17.4 min on average). 62.5% of patients with bleeding > 50 mL developed intra-abdominal collection. CONCLUSIONS: There was no evidence of superiority of either of the two interventions in complicated appendicitis, but it does confirm that single-port laparoscopic appendectomy is a safe, feasible, noninferior procedure and with similar complication rates compared to the conventional laparoscopic appendectomy technique.


Assuntos
Apendicite , Laparoscopia , Apendicectomia , Apendicite/cirurgia , Humanos , Período Pós-Operatório , Estudos Retrospectivos
14.
Int J Radiat Biol ; 97(7): 888-905, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33970757

RESUMO

PURPOSE: In case of a mass-casualty radiological event, there would be a need for networking to overcome surge limitations and to quickly obtain homogeneous results (reported aberration frequencies or estimated doses) among biodosimetry laboratories. These results must be consistent within such network. Inter-laboratory comparisons (ILCs) are widely accepted to achieve this homogeneity. At the European level, a great effort has been made to harmonize biological dosimetry laboratories, notably during the MULTIBIODOSE and RENEB projects. In order to continue the harmonization efforts, the RENEB consortium launched this intercomparison which is larger than the RENEB network, as it involves 38 laboratories from 21 countries. In this ILC all steps of the process were monitored, from blood shipment to dose estimation. This exercise also aimed to evaluate the statistical tools used to compare laboratory performance. MATERIALS AND METHODS: Blood samples were irradiated at three different doses, 1.8, 0.4 and 0 Gy (samples A, C and B) with 4-MV X-rays at 0.5 Gy min-1, and sent to the participant laboratories. Each laboratory was requested to blindly analyze 500 cells per sample and to report the observed frequency of dicentric chromosomes per metaphase and the corresponding estimated dose. RESULTS: This ILC demonstrates that blood samples can be successfully distributed among laboratories worldwide to perform biological dosimetry in case of a mass casualty event. Having achieved a substantial harmonization in multiple areas among the RENEB laboratories issues were identified with the available statistical tools, which are not capable to advantageously exploit the richness of results of a large ILCs. Even though Z- and U-tests are accepted methods for biodosimetry ILCs, setting the number of analyzed metaphases to 500 and establishing a tests' common threshold for all studied doses is inappropriate for evaluating laboratory performance. Another problem highlighted by this ILC is the issue of the dose-effect curve diversity. It clearly appears that, despite the initial advantage of including the scoring specificities of each laboratory, the lack of defined criteria for assessing the robustness of each laboratory's curve is a disadvantage for the 'one curve per laboratory' model. CONCLUSIONS: Based on our study, it seems relevant to develop tools better adapted to the collection and processing of results produced by the participant laboratories. We are confident that, after an initial harmonization phase reached by the RENEB laboratories, a new step toward a better optimization of the laboratory networks in biological dosimetry and associated ILC is on the way.


Assuntos
Laboratórios , Radiometria , Aberrações Cromossômicas/efeitos da radiação , Humanos , Exposição à Radiação , Reprodutibilidade dos Testes
16.
EMBO J ; 40(7): e106018, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33634895

RESUMO

The BRCA2 tumor suppressor is a DNA double-strand break (DSB) repair factor essential for maintaining genome integrity. BRCA2-deficient cells spontaneously accumulate DNA-RNA hybrids, a known source of genome instability. However, the specific role of BRCA2 on these structures remains poorly understood. Here we identified the DEAD-box RNA helicase DDX5 as a BRCA2-interacting protein. DDX5 associates with DNA-RNA hybrids that form in the vicinity of DSBs, and this association is enhanced by BRCA2. Notably, BRCA2 stimulates the DNA-RNA hybrid-unwinding activity of DDX5 helicase. An impaired BRCA2-DDX5 interaction, as observed in cells expressing the breast cancer variant BRCA2-T207A, reduces the association of DDX5 with DNA-RNA hybrids, decreases the number of RPA foci, and alters the kinetics of appearance of RAD51 foci upon irradiation. Our findings are consistent with DNA-RNA hybrids constituting an impediment for the repair of DSBs by homologous recombination and reveal BRCA2 and DDX5 as active players in their removal.


Assuntos
Proteína BRCA2/metabolismo , RNA Helicases DEAD-box/metabolismo , Reparo de DNA por Recombinação , Proteína BRCA2/genética , Linhagem Celular Tumoral , RNA Helicases DEAD-box/genética , Quebras de DNA de Cadeia Dupla , Células HEK293 , Humanos , Ácidos Nucleicos Heteroduplexes , Ligação Proteica
17.
Nat Commun ; 12(1): 338, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33436578

RESUMO

Stably acquired mutations in hematopoietic cells represent substrates of selection that may lead to clonal hematopoiesis (CH), a common state in cancer patients that is associated with a heightened risk of leukemia development. Owing to technical and sample size limitations, most CH studies have characterized gene mutations or mosaic chromosomal alterations (mCAs) individually. Here we leverage peripheral blood sequencing data from 32,442 cancer patients to jointly characterize gene mutations (n = 14,789) and mCAs (n = 383) in CH. Recurrent composite genotypes resembling known genetic interactions in leukemia genomes underlie 23% of all detected autosomal alterations, indicating that these selection mechanisms are operative early in clonal evolution. CH with composite genotypes defines a patient group at high risk of leukemia progression (3-year cumulative incidence 14.6%, CI: 7-22%). Multivariable analysis identifies mCA as an independent risk factor for leukemia development (HR = 14, 95% CI: 6-33, P < 0.001). Our results suggest that mCA should be considered in conjunction with gene mutations in the surveillance of patients at risk of hematologic neoplasms.


Assuntos
Aberrações Cromossômicas , Evolução Clonal/genética , Hematopoiese Clonal/genética , Mutação/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Neoplasias Hematológicas/genética , Humanos , Pessoa de Meia-Idade , Mosaicismo , Neoplasias/genética , Medição de Risco , Seleção Genética , Adulto Jovem
18.
IEEE Trans Haptics ; 14(1): 200-211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32746379

RESUMO

Previous research has shown evidence of tactile speech acquisition of up to 500 English words presented as tactile phonemic patterns using a 4-by-6 tactor array worn on the forearm. This article describes modifications to some of the tactile codes encoding the 39 English phonemes, and ten additional codes as abbreviated patterns for the ten most frequent phoneme pairs in spoken English. The re-design aimed to reduce the duration of phonemes and phoneme pairs that occur most frequently, with the goal to increase tactile speech transmission rates. Code identification experiments were conducted with ten participants over three weeks using a video game. The average identification rate of the 49 modified codes (39 phonemes plus 10 phoneme pairs) was 83.3% with an average learning time of 6.2 hours. The average identification rate of the 49 codes in a retention test with 7 of the 10 participants after more than 90 days of no exposure to the tactile codes was 75.7%. An analysis using ideal transmission rates showed a 58% increase in transmission rate with the modified tactile codes as compared to the original codes, demonstrating that the improved codes can speed up tactile speech communication.


Assuntos
Percepção da Fala , Fala , Humanos , Idioma , Fonética , Tato
19.
BMC Bioinformatics ; 21(1): 549, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33256603

RESUMO

BACKGROUND: The widespread adoption of high throughput technologies has democratized data generation. However, data processing in accordance with best practices remains challenging and the data capital often becomes siloed. This presents an opportunity to consolidate data assets into digital biobanks-ecosystems of readily accessible, structured, and annotated datasets that can be dynamically queried and analysed. RESULTS: We present Isabl, a customizable plug-and-play platform for the processing of multimodal patient-centric data. Isabl's architecture consists of a relational database (Isabl DB), a command line client (Isabl CLI), a RESTful API (Isabl API) and a frontend web application (Isabl Web). Isabl supports automated deployment of user-validated pipelines across the entire data capital. A full audit trail is maintained to secure data provenance, governance and ensuring reproducibility of findings. CONCLUSIONS: As a digital biobank, Isabl supports continuous data utilization and automated meta analyses at scale, and serves as a catalyst for research innovation, new discoveries, and clinical translation.


Assuntos
Bancos de Espécimes Biológicos , Bases de Dados Factuais , Humanos , Internet , Reprodutibilidade dos Testes , Software , Interface Usuário-Computador
20.
Blood Adv ; 4(20): 5246-5256, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33104796

RESUMO

Myeloproliferative neoplasms (MPN) that have evolved into accelerated or blast phase disease (MPN-AP/BP) have poor outcomes with limited treatment options and therefore represent an urgent unmet need. We have previously demonstrated in a multicenter, phase 1 trial conducted through the Myeloproliferative Neoplasms Research Consortium that the combination of ruxolitinib and decitabine is safe and tolerable and is associated with a favorable overall survival (OS). In this phase 2 trial, 25 patients with MPN-AP/BP were treated at the recommended phase 2 dose of ruxolitinib 25 mg twice daily for the induction cycle followed by 10 mg twice daily for subsequent cycles in combination with decitabine 20 mg/m2 for 5 consecutive days in a 28-day cycle. Nineteen patients died during the study follow-up. The median OS for all patients on study was 9.5 months (95% confidence interval, 4.3-12.0). Overall response rate (complete remission + incomplete platelet recovery + partial remission) was 11/25 (44%) and response was not associated with improved survival. We conclude that the combination of decitabine and ruxolitinib was well tolerated, demonstrated favorable OS, and represents a therapeutic option for this high-risk patient population. This trial was registered at www.clinicaltrials.gov as #NCT02076191.


Assuntos
Crise Blástica , Pirazóis , Crise Blástica/tratamento farmacológico , Decitabina/uso terapêutico , Humanos , Nitrilas , Pirazóis/uso terapêutico , Pirimidinas , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA