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1.
Am J Hum Genet ; 110(10): 1616-1627, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37802042

RESUMO

At least 5% of cancer diagnoses are attributed to a causal pathogenic or likely pathogenic germline genetic variant (hereditary cancer syndrome-HCS). These individuals are burdened with lifelong surveillance monitoring organs for a wide spectrum of cancers. This is associated with substantial uncertainty and anxiety in the time between screening tests and while the individuals are awaiting results. Cell-free DNA (cfDNA) sequencing has recently shown potential as a non-invasive strategy for monitoring cancer. There is an opportunity for high-yield cancer early detection in HCS. To assess clinical validity of cfDNA in individuals with HCS, representatives from eight genetics centers from across Canada founded the CHARM (cfDNA in Hereditary and High-Risk Malignancies) Consortium in 2017. In this perspective, we discuss operationalization of this consortium and early data emerging from the most common and well-characterized HCSs: hereditary breast and ovarian cancer, Lynch syndrome, Li-Fraumeni syndrome, and Neurofibromatosis type 1. We identify opportunities for the incorporation of cfDNA sequencing into surveillance protocols; these opportunities are backed by examples of earlier cancer detection efficacy in HCSs from the CHARM Consortium. We seek to establish a paradigm shift in early cancer surveillance in individuals with HCSs, away from highly centralized, regimented medical screening visits and toward more accessible, frequent, and proactive care for these high-risk individuals.


Assuntos
Ácidos Nucleicos Livres , Síndromes Neoplásicas Hereditárias , Feminino , Humanos , Predisposição Genética para Doença , Síndromes Neoplásicas Hereditárias/diagnóstico , Síndromes Neoplásicas Hereditárias/genética , Síndromes Neoplásicas Hereditárias/epidemiologia , Testes Genéticos/métodos , Biópsia Líquida , Ácidos Nucleicos Livres/genética
2.
Proc Natl Acad Sci U S A ; 120(45): e2310057120, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37906643

RESUMO

During aging, the cellular response to unfolded proteins is believed to decline, resulting in diminished proteostasis. In model organisms, such as Caenorhabditis elegans, proteostatic decline with age has been linked to proteome solubility shifts and the onset of protein aggregation. However, this correlation has not been extensively characterized in aging mammals. To uncover age-dependent changes in the insoluble portion of a mammalian proteome, we analyzed the detergent-insoluble fraction of mouse brain tissue by mass spectrometry. We identified a group of 171 proteins, including the small heat shock protein α-crystallin, that become enriched in the detergent-insoluble fraction obtained from old mice. To enhance our ability to detect features associated with proteins in that fraction, we complemented our data with a meta-analysis of studies reporting the detergent-insoluble proteins in various mouse models of aging and neurodegeneration. Strikingly, insoluble proteins from young and old mice are distinct in several features in our study and across the collected literature data. In younger mice, proteins are more likely to be disordered, part of membraneless organelles, and involved in RNA binding. These traits become less prominent with age, as an increased number of structured proteins enter the pellet fraction. This analysis suggests that age-related changes to proteome organization lead a group of proteins with specific features to become detergent-insoluble. Importantly, these features are not consistent with those associated with proteins driving membraneless organelle formation. We see no evidence in our system of a general increase of condensate proteins in the detergent-insoluble fraction with age.


Assuntos
Detergentes , Proteoma , Camundongos , Animais , Proteoma/metabolismo , Detergentes/metabolismo , Envelhecimento , Caenorhabditis elegans/metabolismo , Encéfalo/metabolismo , Mamíferos/metabolismo
3.
Blood ; 142(1): 90-105, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37146239

RESUMO

RNA-binding proteins (RBPs) form a large and diverse class of factors, many members of which are overexpressed in hematologic malignancies. RBPs participate in various processes of messenger RNA (mRNA) metabolism and prevent harmful DNA:RNA hybrids or R-loops. Here, we report that PIWIL4, a germ stem cell-associated RBP belonging to the RNase H-like superfamily, is overexpressed in patients with acute myeloid leukemia (AML) and is essential for leukemic stem cell function and AML growth, but dispensable for healthy human hematopoietic stem cells. In AML cells, PIWIL4 binds to a small number of known piwi-interacting RNA. Instead, it largely interacts with mRNA annotated to protein-coding genic regions and enhancers that are enriched for genes associated with cancer and human myeloid progenitor gene signatures. PIWIL4 depletion in AML cells downregulates the human myeloid progenitor signature and leukemia stem cell (LSC)-associated genes and upregulates DNA damage signaling. We demonstrate that PIWIL4 is an R-loop resolving enzyme that prevents R-loop accumulation on a subset of AML and LSC-associated genes and maintains their expression. It also prevents DNA damage, replication stress, and activation of the ATR pathway in AML cells. PIWIL4 depletion potentiates sensitivity to pharmacological inhibition of the ATR pathway and creates a pharmacologically actionable dependency in AML cells.


Assuntos
Leucemia Mieloide Aguda , Humanos , Leucemia Mieloide Aguda/patologia , Células-Tronco Hematopoéticas/metabolismo , Proliferação de Células , Genômica , RNA Mensageiro/metabolismo , Células-Tronco Neoplásicas/patologia
4.
Clin Chem ; 70(1): 273-284, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38175592

RESUMO

BACKGROUND: Somatic hypermutation (SHM) status of the immunoglobulin heavy variable (IGHV) gene plays a crucial role in determining the prognosis and treatment of patients with chronic lymphocytic leukemia (CLL). A common approach for determining SHM status is multiplex polymerase chain reaction and Sanger sequencing of the immunoglobin heavy locus; however, this technique is low throughput, is vulnerable to failure, and does not allow multiplexing with other diagnostic assays. METHODS: Here we designed and validated a DNA targeted capture approach to detect immunoglobulin heavy variable somatic hypermutation (IGHV SHM) status as a submodule of a larger next-generation sequencing (NGS) panel that also includes probes for ATM, BIRC3, CHD2, KLHL6, MYD88, NOTCH1, NOTCH2, POT1, SF3B1, TP53, and XPO1. The assay takes as input FASTQ files and outputs a report containing IGHV SHM status and V allele usage following European Research Initiative on CLL guidelines. RESULTS: We validated the approach on 35 CLL patient samples, 34 of which were characterized using Sanger sequencing. The NGS panel identified the IGHV SHM status of 34 of 35 CLL patients. We showed 100% sensitivity and specificity among the 33 CLL samples with both NGS and Sanger sequencing calls. Furthermore, we demonstrated that this panel can be combined with additional targeted capture panels to detect prognostically important CLL single nucleotide variants, insertions/deletions, and copy number variants (TP53 copy number loss). CONCLUSIONS: A targeted capture approach to IGHV SHM detection can be integrated into broader sequencing panels, allowing broad CLL prognostication in a single molecular assay.


Assuntos
Leucemia Linfocítica Crônica de Células B , Hipermutação Somática de Imunoglobulina , Humanos , Alelos , Sequenciamento de Nucleotídeos em Larga Escala , Imunoglobulinas , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/genética , Fatores de Transcrição
5.
Blood ; 140(10): 1067-1074, 2022 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-35468199

RESUMO

Chronic inflammation with aging ("inflammaging") plays a prominent role in the pathogenesis of myeloid malignancies. Aberrant inflammatory activity affects many different cells in the marrow, including normal blood and stromal marrow elements and leukemic cells, in unique and distinct ways. Inflammation can promote selective clonal expansion through differential immune-mediated suppression of normal hematopoietic cells and malignant clones. We review these complex roles, how they can be understood by separating cell-intrinsic from extrinsic effects, and how this informs future clinical trials.


Assuntos
Transtornos Mieloproliferativos , Neoplasias , Envelhecimento/patologia , Medula Óssea/patologia , Humanos , Inflamação/patologia , Transtornos Mieloproliferativos/patologia , Neoplasias/patologia
6.
J Med Genet ; 59(6): 571-578, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33875564

RESUMO

BACKGROUND: This study aimed to identify and resolve discordant variant interpretations across clinical molecular genetic laboratories through the Canadian Open Genetics Repository (COGR), an online collaborative effort for variant sharing and interpretation. METHODS: Laboratories uploaded variant data to the Franklin Genoox platform. Reports were issued to each laboratory, summarising variants where conflicting classifications with another laboratory were noted. Laboratories could then reassess variants to resolve discordances. Discordance was calculated using a five-tier model (pathogenic (P), likely pathogenic (LP), variant of uncertain significance (VUS), likely benign (LB), benign (B)), a three-tier model (LP/P are positive, VUS are inconclusive, LB/B are negative) and a two-tier model (LP/P are clinically actionable, VUS/LB/B are not). We compared the COGR classifications to automated classifications generated by Franklin. RESULTS: Twelve laboratories submitted classifications for 44 510 unique variants. 2419 variants (5.4%) were classified by two or more laboratories. From baseline to after reassessment, the number of discordant variants decreased from 833 (34.4% of variants reported by two or more laboratories) to 723 (29.9%) based on the five-tier model, 403 (16.7%) to 279 (11.5%) based on the three-tier model and 77 (3.2%) to 37 (1.5%) based on the two-tier model. Compared with the COGR classification, the automated Franklin classifications had 94.5% sensitivity and 96.6% specificity for identifying actionable (P or LP) variants. CONCLUSIONS: The COGR provides a standardised mechanism for laboratories to identify discordant variant interpretations and reduce discordance in genetic test result delivery. Such quality assurance programmes are important as genetic testing is implemented more widely in clinical care.


Assuntos
Variação Genética , Laboratórios , Canadá , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Disseminação de Informação/métodos
7.
Oncologist ; 27(5): e393-e401, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35385106

RESUMO

BACKGROUND: We explored health professionals' views on the utility of circulating tumor DNA (ctDNA) testing in hereditary cancer syndrome (HCS) management. MATERIALS AND METHODS: A qualitative interpretive description study was conducted, using semi-structured interviews with professionals across Canada. Thematic analysis employing constant comparison was used for analysis. 2 investigators coded each transcript. Differences were reconciled through discussion and the codebook was modified as new codes and themes emerged from the data. RESULTS: Thirty-five professionals participated and included genetic counselors (n = 12), geneticists (n = 9), oncologists (n = 4), family doctors (n = 3), lab directors and scientists (n = 3), a health-system decision maker, a surgeon, a pathologist, and a nurse. Professionals described ctDNA as "transformative" and a "game-changer". However, they were divided on its use in HCS management, with some being optimistic (optimists) while others were hesitant (pessimists). Differences were driven by views on 3 factors: (1) clinical utility, (2) ctDNA's role in cancer screening, and (3) ctDNA's invasiveness. Optimists anticipated ctDNA testing would have clinical utility for HCS patients, its role would be akin to a diagnostic test and would be less invasive than standard screening (eg imaging). Pessimistic participants felt ctDNA testing would add limited utility; it would effectively be another screening test in the pathway, likely triggering additional investigations downstream, thereby increasing invasiveness. CONCLUSIONS: Providers anticipated ctDNA testing will transform early cancer detection for HCS families. However, the contrasting positions on ctDNA's role in the care pathway raise potential practice variations, highlighting a need to develop evidence to support clinical implementation and guidelines to standardize adoption.


Assuntos
DNA Tumoral Circulante , Síndromes Neoplásicas Hereditárias , DNA Tumoral Circulante/genética , Detecção Precoce de Câncer/métodos , Pessoal de Saúde , Humanos , Pesquisa Qualitativa
8.
Blood ; 135(25): 2235-2251, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32384151

RESUMO

Aging is associated with significant changes in the hematopoietic system, including increased inflammation, impaired hematopoietic stem cell (HSC) function, and increased incidence of myeloid malignancy. Inflammation of aging ("inflammaging") has been proposed as a driver of age-related changes in HSC function and myeloid malignancy, but mechanisms linking these phenomena remain poorly defined. We identified loss of miR-146a as driving aging-associated inflammation in AML patients. miR-146a expression declined in old wild-type mice, and loss of miR-146a promoted premature HSC aging and inflammation in young miR-146a-null mice, preceding development of aging-associated myeloid malignancy. Using single-cell assays of HSC quiescence, stemness, differentiation potential, and epigenetic state to probe HSC function and population structure, we found that loss of miR-146a depleted a subpopulation of primitive, quiescent HSCs. DNA methylation and transcriptome profiling implicated NF-κB, IL6, and TNF as potential drivers of HSC dysfunction, activating an inflammatory signaling relay promoting IL6 and TNF secretion from mature miR-146a-/- myeloid and lymphoid cells. Reducing inflammation by targeting Il6 or Tnf was sufficient to restore single-cell measures of miR-146a-/- HSC function and subpopulation structure and reduced the incidence of hematological malignancy in miR-146a-/- mice. miR-146a-/- HSCs exhibited enhanced sensitivity to IL6 stimulation, indicating that loss of miR-146a affects HSC function via both cell-extrinsic inflammatory signals and increased cell-intrinsic sensitivity to inflammation. Thus, loss of miR-146a regulates cell-extrinsic and -intrinsic mechanisms linking HSC inflammaging to the development of myeloid malignancy.


Assuntos
Envelhecimento/genética , Inflamação/genética , Interleucina-6/fisiologia , Leucemia Mieloide Aguda/etiologia , MicroRNAs/genética , Fator de Necrose Tumoral alfa/fisiologia , Adolescente , Adulto , Idoso , Envelhecimento/imunologia , Animais , Diferenciação Celular , Autorrenovação Celular , Senescência Celular , Citocinas/biossíntese , Metilação de DNA , Feminino , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Inflamação/fisiopatologia , Interleucina-6/antagonistas & inibidores , Masculino , Camundongos , Camundongos Knockout , MicroRNAs/biossíntese , Pessoa de Meia-Idade , NF-kappa B/fisiologia , Análise de Célula Única , Transcriptoma , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto Jovem
9.
Blood ; 136(2): 157-170, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32347921

RESUMO

The 2016 revision of the World Health Organization classification of tumors of hematopoietic and lymphoid tissues is characterized by a closer integration of morphology and molecular genetics. Notwithstanding, the myelodysplastic syndrome (MDS) with isolated del(5q) remains so far the only MDS subtype defined by a genetic abnormality. Approximately half of MDS patients carry somatic mutations in spliceosome genes, with SF3B1 being the most commonly mutated one. SF3B1 mutation identifies a condition characterized by ring sideroblasts (RS), ineffective erythropoiesis, and indolent clinical course. A large body of evidence supports recognition of SF3B1-mutant MDS as a distinct nosologic entity. To further validate this notion, we interrogated the data set of the International Working Group for the Prognosis of MDS (IWG-PM). Based on the findings of our analyses, we propose the following diagnostic criteria for SF3B1-mutant MDS: (1) cytopenia as defined by standard hematologic values, (2) somatic SF3B1 mutation, (3) morphologic dysplasia (with or without RS), and (4) bone marrow blasts <5% and peripheral blood blasts <1%. Selected concomitant genetic lesions represent exclusion criteria for the proposed entity. In patients with clonal cytopenia of undetermined significance, SF3B1 mutation is almost invariably associated with subsequent development of overt MDS with RS, suggesting that this genetic lesion might provide presumptive evidence of MDS in the setting of persistent unexplained cytopenia. Diagnosis of SF3B1-mutant MDS has considerable clinical implications in terms of risk stratification and therapeutic decision making. In fact, this condition has a relatively good prognosis and may respond to luspatercept with abolishment of the transfusion requirement.


Assuntos
Medula Óssea/metabolismo , Eritropoese , Mutação , Síndromes Mielodisplásicas , Fosfoproteínas/genética , Fatores de Processamento de RNA/genética , Humanos , Síndromes Mielodisplásicas/classificação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/terapia , Prognóstico , Medição de Risco
10.
Eur J Haematol ; 108(5): 437-445, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35122325

RESUMO

OBJECTIVES: Acute myeloid leukaemia (AML) is a disease of older adults, who are vulnerable to socio-economic factors. We determined AML incidence in older adults and the impact of socio-economic factors on outcomes. METHODS: We included 3024 AML patients (1996-2016) identified from a population-based registry. RESULTS: AML incidence in patients ≥60 years increased from 11.01 (2001-2005) to 12.76 (2011-2016) per 100 000 population. Among 879 patients ≥60 years in recent eras (2010-2016), rural residents (<100 000 population) were less likely to be assessed by a leukaemia specialist (39% rural, 47% urban, p = .032); no difference was seen for lower (43%, quintile 1-3) vs. higher (47%, quintile 4-5) incomes (p = .235). Similar numbers received induction chemotherapy between residence (16% rural, 18% urban, p = .578) and incomes (17% lower, 17% high, p = 1.0). Differences between incomes were seen for hypomethylating agent treatment (14% low, 20% high, p = .041); this was not seen for residence (13% rural, 18% urban, p = .092). Among non-adverse karyotype patients ≥70 years, 2-year overall survival was worse for rural (5% rural, 12% urban, p = .006) and lower income (6% low, 15% high, p = .017) patients. CONCLUSIONS: AML incidence in older adults is increasing, and outcomes are worse for older rural and low-income residents; these patients face treatment barriers.


Assuntos
Leucemia Mieloide Aguda , Idoso , Estudos de Coortes , Humanos , Incidência , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/epidemiologia , População Rural , Fatores Socioeconômicos
11.
Clin Chem Lab Med ; 60(2): 183-190, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-34761647

RESUMO

OBJECTIVES: Non-invasive prenatal testing requires the presence of fetal DNA in maternal plasma. Understanding how preexamination conditions affect the integrity of cell-free DNA (cfDNA) and fetal fraction (FF) are a prerequisite for test implementation. Therefore, we examined the adjusted effect that EDTA and Streck tubes have on the cfDNA quantity and FF. METHODS: A total of 3,568 maternal blood samples across Canada were collected in either EDTA, or Streck tubes, and processing metrics, maternal body mass index (BMI), gestational age and fetal karyotype and sex were recorded. Plasma samples were sequenced using two different sequencing platforms in separate laboratories. Sequencing data were processed with SeqFF to estimate FF. Linear regression and multivariate imputation by chained equations were used to estimate the adjusted effect of tube type on cfDNA and FF. RESULTS: We found a positive association between cfDNA quantity and blood shipment time in EDTA tubes, which is significantly reduced with the use of Streck tubes. Furthermore, we show the storage of plasma at -80 °C is associated with a 4.4% annual relative decrease in cfDNA levels. FF was not associated with collection tube type when controlling for confounding variables. However, FF was positively associated with gestational age and trisomy 21, while negatively associated with BMI, male fetus, trisomy 18, Turners syndrome and triploidy. CONCLUSIONS: Preexamination, maternal and fetal variables are associated with cfDNA quantity and FF. The consideration of these variables in future studies may help to reduce the number of pregnant women with inconclusive tests as a result of low FF.


Assuntos
Ácidos Nucleicos Livres , Síndrome de Down , Síndrome de Down/diagnóstico , Feminino , Humanos , Masculino , Gravidez , Diagnóstico Pré-Natal , Trissomia , Síndrome da Trissomía do Cromossomo 18/diagnóstico
12.
Br J Haematol ; 190(6): 864-868, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32510594

RESUMO

Despite continuing improvements in the management of classical Hodgkin lymphoma (cHL), relapse remains associated with a risk of lymphoma-related mortality. The biological composition of relapse tumour biopsies shows interpatient variability, which can be leveraged to design prognostic biomarkers. Here, we validated the RHL30 assay, a previously reported gene expression model in an independent cohort of 41 patients with relapsed cHL. Patients classified as high-risk by the RHL30 assay had inferior failure-free survival (FFS) after autologous stem cell transplantation (2-year FFS 41% vs. 92%, P = 0·035). The RHL30 model is a robust biomarker that risk-stratifies patients considered for autologous stem cell transplantation.


Assuntos
Biomarcadores Tumorais/biossíntese , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin , Adulto , Autoenxertos , Feminino , Doença de Hodgkin/metabolismo , Doença de Hodgkin/mortalidade , Doença de Hodgkin/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
13.
Genet Med ; 22(11): 1892-1897, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32624572

RESUMO

PURPOSE: Structural variants (SVs) may be an underestimated cause of hereditary cancer syndromes given the current limitations of short-read next-generation sequencing. Here we investigated the utility of long-read sequencing in resolving germline SVs in cancer susceptibility genes detected through short-read genome sequencing. METHODS: Known or suspected deleterious germline SVs were identified using Illumina genome sequencing across a cohort of 669 advanced cancer patients with paired tumor genome and transcriptome sequencing. Candidate SVs were subsequently assessed by Oxford Nanopore long-read sequencing. RESULTS: Nanopore sequencing confirmed eight simple pathogenic or likely pathogenic SVs, resolving three additional variants whose impact could not be fully elucidated through short-read sequencing. A recurrent sequencing artifact on chromosome 16p13 and one complex rearrangement on chromosome 5q35 were subsequently classified as likely benign, obviating the need for further clinical assessment. Variant configuration was further resolved in one case with a complex pathogenic rearrangement affecting TSC2. CONCLUSION: Our findings demonstrate that long-read sequencing can improve the validation, resolution, and classification of germline SVs. This has important implications for return of results, cascade carrier testing, cancer screening, and prophylactic interventions.


Assuntos
Predisposição Genética para Doença , Neoplasias , Sequência de Bases , Genoma , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
14.
Bioinformatics ; 33(17): 2737-2739, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28475666

RESUMO

SUMMARY: Massively parallel sequencing is now widely used, but data interpretation is only as good as the reference assembly to which it is aligned. While the number of reference assemblies has rapidly expanded, most of these remain at intermediate stages of completion, either as scaffold builds, or as chromosome builds (consisting of correctly ordered, but not necessarily correctly oriented scaffolds separated by gaps). Completion of de novo assemblies remains difficult, as regions that are repetitive or hard to sequence prevent the accumulation of larger scaffolds, and create errors such as misorientations and mislocalizations. Thus, complementary methods for determining the orientation and positioning of fragments are important for finishing assemblies. Strand-seq is a method for determining template strand inheritance in single cells, information that can be used to determine relative genomic distance and orientation between scaffolds, and find errors within them. We present contiBAIT, an R/Bioconductor package which uses Strand-seq data to repair and improve existing assemblies. AVAILABILITY AND IMPLEMENTATION: contiBAIT is available on Bioconductor. Source files available from GitHub. CONTACT: koneill@bcgsc.ca or mark.hills@stemcell.com. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Software , Algoritmos , Genômica/métodos , Humanos
15.
Genet Med ; 20(3): 294-302, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28726806

RESUMO

PurposeThe purpose of this study was to develop a national program for Canadian diagnostic laboratories to compare DNA-variant interpretations and resolve discordant-variant classifications using the BRCA1 and BRCA2 genes as a case study.MethodsBRCA1 and BRCA2 variant data were uploaded and shared through the Canadian Open Genetics Repository (COGR; http://www.opengenetics.ca). A total of 5,554 variant observations were submitted; classification differences were identified and comparison reports were sent to participating laboratories. Each site had the opportunity to reclassify variants. The data were analyzed before and after the comparison report process to track concordant- or discordant-variant classifications by three different models.ResultsVariant-discordance rates varied by classification model: 38.9% of variants were discordant when using a five-tier model, 26.7% with a three-tier model, and 5.0% with a two-tier model. After the comparison report process, the proportion of discordant variants dropped to 30.7% with the five-tier model, to 14.2% with the three-tier model, and to 0.9% using the two-tier model.ConclusionWe present a Canadian interinstitutional quality improvement program for DNA-variant interpretations. Sharing of variant knowledge by clinical diagnostic laboratories will allow clinicians and patients to make more informed decisions and lead to better patient outcomes.


Assuntos
Confiabilidade dos Dados , Testes Genéticos/normas , Disseminação de Informação , Melhoria de Qualidade , Canadá , Tomada de Decisão Clínica , Bases de Dados Genéticas , Genes BRCA1 , Genes BRCA2 , Aconselhamento Genético , Testes Genéticos/métodos , Variação Genética , Programas Governamentais , Humanos , Reprodutibilidade dos Testes , Fluxo de Trabalho
16.
Artigo em Inglês | MEDLINE | ID: mdl-29541281

RESUMO

BACKGROUND: Approximately 5% to 10% of pancreatic ductal adenocarcinoma (PDAC) has a hereditary basis. In most of these defined hereditary cancer syndromes, PDAC is not the predominant cancer type. Traditional criteria for publicly funded genetic testing typically require the presence of a set combination of the predominant syndrome-associated cancer types in the family history.We report the identification of a CDKN2A pathogenic variant in a PDAC-prone family without the cutaneous features of multiple moles or melanoma that are characteristic of the Familial Atypical Multiple Mole Melanoma (FAMMM) Syndrome identified in a universal testing algorithm for inherited mutations in pancreatic cancer patients. CASE PRESENTATION: We present the case of two brothers of English ancestry diagnosed with PDAC within the same 12 month period, at the respective ages of 63 and 64 years of age. Neither brother reported a personal history of multiple moles or melanoma. Family history was positive for two second-degree relatives diagnosed with PDAC but was negative for other cancers or multiple moles in first- and second-degree relatives. Due to the absence of melanoma, this family did not meet provincial criteria for publicly funded genetic testing. Clinical genetic testing offered through a research grant identified a pathogenic variant in the CDKN2A gene c.377 T > A (p.Val126Asp). This variant is a North American founder mutation believed to pre-date colonization. CONCLUSIONS: This case reminds clinicians to consider the possibility of a germline CDKN2A mutation in families with a high prevalence of PDAC, even in the absence of moles or melanoma. This case supports recent guidelines published by the American College of Medical Genetics and Genomics (ACMG) that genetics referrals are indicated in families with three or more cases of PDAC regardless of other cancer types in the family. A multi-gene panel approach is of particular benefit in diagnosing inherited cancer susceptibility in PDAC-only families.

18.
Gynecol Oncol ; 147(3): 663-671, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29079036

RESUMO

OBJECTIVE: APELA is a small, secreted peptide that can function as a ligand for the G-protein coupled receptor, Apelin Receptor (APLNR, APJ). APELA plays an essential role in endoderm differentiation and cardiac development during embryogenesis. We investigated whether APELA exerts any functions in cancer progression. METHODS: The Cancer Genome Atlas (TCGA) RNA sequencing datasets, microarray from an OCCC mouse model, and RNA isolated from fresh frozen and FFPE patient tissue were used to assess APELA expression. APELA knockout ovarian clear cell carcinoma (OCCC) cell lines were generated using CRISPR/Cas9. RESULTS: APELA was expressed in various ovarian cancer histotypes and was especially elevated in OCCC. Disruption of APELA expression in OCCC cell lines suppressed cell growth and migration, and altered cell-cycle progression. Moreover, addition of human recombinant APELA peptide to the OCCC cell line OVISE promoted cell growth and migration. Interestingly, OVISE cells do not express APLNR, suggesting that APELA can function through an APLNR-independent pathway. Furthermore, APELA affected cell growth and cell cycle progression in a p53-dependent manner. In addition, APELA knockdown induced p53 expression in cancer cell lines. CONCLUSIONS: Our findings uncover a potential oncogenic role for APELA in promoting ovarian tumour progression and provide a possible therapeutic strategy in ovarian cancer by targeting APELA.


Assuntos
Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Hormônios Peptídicos/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apelina/metabolismo , Receptores de Apelina/metabolismo , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Feminino , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID
19.
Genes Chromosomes Cancer ; 55(1): 16-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26391112

RESUMO

Deletion of the long arm of chromosome 13 (del(13q)) as the sole abnormality in chronic lymphocytic leukemia (CLL) portends a good prognosis; however, there is great outcome heterogeneity within this subgroup. The percentage of cells with a del(13q) (clone size) and the extent of the deletion are two factors that may affect outcome in CLL patients with isolated del(13q). We analyzed 248 CLL patients from the BC Provincial CLL database identified as having isolated del(13q) detected pretreatment by interphase fluorescence in situ hybridization to determine what impact clone and deletion size had on overall survival (OS) and treatment free survival (TFS). Patients with 60% or more of nuclei with a del(13q) had shorter TFS and shorter OS. A large deletion, encompassing the RB1 gene locus, was detected in half of the 90 cases with available specimens for testing, and there was no significant difference in OS and TFS between RB1-deleted and RB1-not-deleted cases. Further study in a larger sample size is required to determine the clinical interest of RB1 locus testing; however, clone size of del(13q) does predict TFS and OS and may better refine prognosis in this clinically heterogeneous population.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 13/genética , Leucemia Linfocítica Crônica de Células B/patologia , Proteínas Salivares Ricas em Prolina/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Colúmbia Britânica , Núcleo Celular/genética , Feminino , Heterogeneidade Genética , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida
20.
Br J Haematol ; 174(4): 526-35, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27098559

RESUMO

Acute Myeloid Leukaemia (AML) is a rare but serious group of diseases that require critical decision-making for curative treatment. Over the past decade, scientific discovery has revealed dozens of prognostic gene mutations for AML while sequencing costs have plummeted. In this study, we compared the cost-effectiveness of multigene integrative analysis (genomic analysis) with the standard molecular testing currently used for diagnosis of intermediate-risk AML. We used a decision analytic model with data for costs and outcomes from British Columbia, Canada, to assess the long-term (10-year) economic impacts. Our results suggest that genomic analysis would result in a 26% increase in the use of first-remission allogeneic stem cell transplantation. The resulting treatment decisions and downstream effects would come at an additional cost of $12 556 [2013 Canadian dollars (CAD)] per person and the incremental cost-effectiveness ratio would be $49 493 per quality-adjusted life-year gained. Cost-effectiveness was dependent on quality of life during the long-term (5-10) years of survival, relapse rates following first-remission chemotherapy and the upfront cost of transplantation. Non-relapse mortality rates, short-term quality of life and the cost of genomic sequencing had only minor impacts. Further research on post-remission outcomes can lead to improvements in the cost-effectiveness of curative treatments for AML.


Assuntos
Técnicas de Apoio para a Decisão , Leucemia Mieloide Aguda/economia , Adulto , Canadá , Análise Custo-Benefício , Genômica , Transplante de Células-Tronco Hematopoéticas/economia , Humanos , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Recidiva , Indução de Remissão , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
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