Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
1.
PLoS One ; 18(11): e0293879, 2023.
Article in English | MEDLINE | ID: mdl-37943810

ABSTRACT

Science, technology, engineering, mathematics, and medicine (STEMM) fields change rapidly and are increasingly interdisciplinary. Commonly, STEMM practitioners use short-format training (SFT) such as workshops and short courses for upskilling and reskilling, but unaddressed challenges limit SFT's effectiveness and inclusiveness. Education researchers, students in SFT courses, and organizations have called for research and strategies that can strengthen SFT in terms of effectiveness, inclusiveness, and accessibility across multiple dimensions. This paper describes the project that resulted in a consensus set of 14 actionable recommendations to systematically strengthen SFT. A diverse international group of 30 experts in education, accessibility, and life sciences came together from 10 countries to develop recommendations that can help strengthen SFT globally. Participants, including representation from some of the largest life science training programs globally, assembled findings in the educational sciences and encompassed the experiences of several of the largest life science SFT programs. The 14 recommendations were derived through a Delphi method, where consensus was achieved in real time as the group completed a series of meetings and tasks designed to elicit specific recommendations. Recommendations cover the breadth of SFT contexts and stakeholder groups and include actions for instructors (e.g., make equity and inclusion an ethical obligation), programs (e.g., centralize infrastructure for assessment and evaluation), as well as organizations and funders (e.g., professionalize training SFT instructors; deploy SFT to counter inequity). Recommendations are aligned with a purpose-built framework-"The Bicycle Principles"-that prioritizes evidenced-based teaching, inclusiveness, and equity, as well as the ability to scale, share, and sustain SFT. We also describe how the Bicycle Principles and recommendations are consistent with educational change theories and can overcome systemic barriers to delivering consistently effective, inclusive, and career-spanning SFT.


Subject(s)
Students , Technology , Humans , Consensus , Engineering
2.
PLoS Comput Biol ; 19(1): e1010752, 2023 01.
Article in English | MEDLINE | ID: mdl-36622853

ABSTRACT

There is an ongoing explosion of scientific datasets being generated, brought on by recent technological advances in many areas of the natural sciences. As a result, the life sciences have become increasingly computational in nature, and bioinformatics has taken on a central role in research studies. However, basic computational skills, data analysis, and stewardship are still rarely taught in life science educational programs, resulting in a skills gap in many of the researchers tasked with analysing these big datasets. In order to address this skills gap and empower researchers to perform their own data analyses, the Galaxy Training Network (GTN) has previously developed the Galaxy Training Platform (https://training.galaxyproject.org), an open access, community-driven framework for the collection of FAIR (Findable, Accessible, Interoperable, Reusable) training materials for data analysis utilizing the user-friendly Galaxy framework as its primary data analysis platform. Since its inception, this training platform has thrived, with the number of tutorials and contributors growing rapidly, and the range of topics extending beyond life sciences to include topics such as climatology, cheminformatics, and machine learning. While initially aimed at supporting researchers directly, the GTN framework has proven to be an invaluable resource for educators as well. We have focused our efforts in recent years on adding increased support for this growing community of instructors. New features have been added to facilitate the use of the materials in a classroom setting, simplifying the contribution flow for new materials, and have added a set of train-the-trainer lessons. Here, we present the latest developments in the GTN project, aimed at facilitating the use of the Galaxy Training materials by educators, and its usage in different learning environments.


Subject(s)
Computational Biology , Software , Humans , Computational Biology/methods , Data Analysis , Research Personnel
3.
Bioinformatics ; 37(22): 4100-4107, 2021 11 18.
Article in English | MEDLINE | ID: mdl-34028547

ABSTRACT

MOTIVATION: Seurat is one of the most popular software suites for the analysis of single-cell RNA sequencing data. Considering the popularity of the tidyverse ecosystem, which offers a large set of data display, query, manipulation, integration and visualization utilities, a great opportunity exists to interface the Seurat object with the tidyverse. This interface gives the large data science community of tidyverse users the possibility to operate with familiar grammar. RESULTS: To provide Seurat with a tidyverse-oriented interface without compromising efficiency, we developed tidyseurat, a lightweight adapter to the tidyverse. Tidyseurat displays cell information as a tibble abstraction, allowing intuitively interfacing Seurat with dplyr, tidyr, ggplot2 and plotly packages powering efficient data manipulation, integration and visualization. Iterative analyses on data subsets are enabled by interfacing with the popular nest-map framework. AVAILABILITY AND IMPLEMENTATION: The software is freely available at cran.r-project.org/web/packages/tidyseurat and github.com/stemangiola/tidyseurat. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Ecosystem , Software
4.
Methods Mol Biol ; 2284: 367-392, 2021.
Article in English | MEDLINE | ID: mdl-33835453

ABSTRACT

A complete RNA-Seq analysis involves the use of several different tools, with substantial software and computational requirements. The Galaxy platform simplifies the execution of such bioinformatics analyses by embedding the needed tools in its web interface, while also providing reproducibility. Here, we describe how to perform a reference-based RNA-Seq analysis using Galaxy, from data upload to visualization and functional enrichment analysis of differentially expressed genes.


Subject(s)
RNA-Seq/methods , Software , Animals , Computational Biology/methods , Data Analysis , Datasets as Topic/statistics & numerical data , Gene Expression Profiling/methods , Gene Expression Profiling/statistics & numerical data , High-Throughput Nucleotide Sequencing/methods , High-Throughput Nucleotide Sequencing/statistics & numerical data , Humans , Reproducibility of Results , Sequence Analysis, RNA/methods , Sequence Analysis, RNA/statistics & numerical data , Exome Sequencing/methods , Exome Sequencing/statistics & numerical data
6.
Genome Biol ; 22(1): 42, 2021 01 22.
Article in English | MEDLINE | ID: mdl-33482892

ABSTRACT

Recently, efforts have been made toward the harmonization of transcriptomic data structures and workflows using the concept of data tidiness, to facilitate modularisation. We present tidybulk, a modular framework for bulk transcriptional analyses that introduces a tidy transcriptomic data structure paradigm and analysis grammar. Tidybulk covers a wide variety of analysis procedures and integrates a large ecosystem of publicly available analysis algorithms under a common framework. Tidybulk decreases coding burden, facilitates reproducibility, increases efficiency for expert users, lowers the learning curve for inexperienced users, and bridges transcriptional data analysis with the tidyverse. Tidybulk is available at R/Bioconductor bioconductor.org/packages/tidybulk .


Subject(s)
Data Analysis , Transcriptome , Algorithms , Computational Biology/methods , Ecosystem , Gene Expression Profiling/methods , Genomics/methods , Reproducibility of Results , Software
7.
Gigascience ; 9(10)2020 10 20.
Article in English | MEDLINE | ID: mdl-33079170

ABSTRACT

BACKGROUND: The vast ecosystem of single-cell RNA-sequencing tools has until recently been plagued by an excess of diverging analysis strategies, inconsistent file formats, and compatibility issues between different software suites. The uptake of 10x Genomics datasets has begun to calm this diversity, and the bioinformatics community leans once more towards the large computing requirements and the statistically driven methods needed to process and understand these ever-growing datasets. RESULTS: Here we outline several Galaxy workflows and learning resources for single-cell RNA-sequencing, with the aim of providing a comprehensive analysis environment paired with a thorough user learning experience that bridges the knowledge gap between the computational methods and the underlying cell biology. The Galaxy reproducible bioinformatics framework provides tools, workflows, and trainings that not only enable users to perform 1-click 10x preprocessing but also empower them to demultiplex raw sequencing from custom tagged and full-length sequencing protocols. The downstream analysis supports a range of high-quality interoperable suites separated into common stages of analysis: inspection, filtering, normalization, confounder removal, and clustering. The teaching resources cover concepts from computer science to cell biology. Access to all resources is provided at the singlecell.usegalaxy.eu portal. CONCLUSIONS: The reproducible and training-oriented Galaxy framework provides a sustainable high-performance computing environment for users to run flexible analyses on both 10x and alternative platforms. The tutorials from the Galaxy Training Network along with the frequent training workshops hosted by the Galaxy community provide a means for users to learn, publish, and teach single-cell RNA-sequencing analysis.


Subject(s)
Ecosystem , Software , Computational Biology , RNA , Sequence Analysis, RNA
8.
Sci Adv ; 6(18)2020 05.
Article in English | MEDLINE | ID: mdl-32917631

ABSTRACT

The RNA polymerase II (POLII)-driven transcription cycle is tightly regulated at distinct checkpoints by cyclin-dependent kinases (CDKs) and their cognate cyclins. The molecular events underpinning transcriptional elongation, processivity, and the CDK-cyclin pair(s) involved remain poorly understood. Using CRISPR-Cas9 homology-directed repair, we generated analog-sensitive kinase variants of CDK12 and CDK13 to probe their individual and shared biological and molecular roles. Single inhibition of CDK12 or CDK13 induced transcriptional responses associated with cellular growth signaling pathways and/or DNA damage, with minimal effects on cell viability. In contrast, dual kinase inhibition potently induced cell death, which was associated with extensive genome-wide transcriptional changes including widespread use of alternative 3' polyadenylation sites. At the molecular level, dual kinase inhibition resulted in the loss of POLII CTD phosphorylation and greatly reduced POLII elongation rates and processivity. These data define substantial redundancy between CDK12 and CDK13 and identify both as fundamental regulators of global POLII processivity and transcription elongation.

9.
BMC Res Notes ; 13(1): 349, 2020 Jul 22.
Article in English | MEDLINE | ID: mdl-32698852

ABSTRACT

OBJECTIVE: Ovarian fibromas and adenofibromas are rare ovarian tumours. They are benign tumours composed of spindle-like stromal cells (pure fibroma) or a mixture of fibroblast and epithelial components (adenofibroma). We have previously shown that 40% of benign serous ovarian tumours are likely primary fibromas due to the neoplastic alterations being restricted to the stromal compartment of these tumours. We further explore this finding by comparing benign serous tumours to pure fibromas. RESULTS: Performing copy number aberration (CNA) analysis on the stromal component of 45 benign serous tumours and 8 pure fibromas, we have again shown that trisomy of chromosome 12 is the most common aberration in ovarian fibromas. CNAs were more frequent in the pure fibromas than the benign serous tumours (88% vs 33%), however pure fibromas more frequently harboured more than one CNA event compared with benign serous tumours. As these extra CNA events observed in the pure fibromas were unique to this subset our data indicates a unique tumour evolution. Gene expression analysis on the two cohorts was unable to show gene expression changes that differed based on tumour subtype. Exome analysis did not reveal any recurrently mutated genes.


Subject(s)
Fibroma , Ovarian Neoplasms , DNA Copy Number Variations , Exome , Female , Fibroma/genetics , Humans , Ovarian Neoplasms/genetics , Trisomy
10.
BMC Cancer ; 20(1): 369, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32357859

ABSTRACT

BACKGROUND: Familial cases of appendiceal mucinous tumours (AMTs) are extremely rare and the underlying genetic aetiology uncertain. We identified potential predisposing germline genetic variants in a father and daughter with AMTs presenting with pseudomyxoma peritonei (PMP) and correlated these with regions of loss of heterozygosity (LOH) in the tumours. METHODS: Through germline whole exome sequencing, we identified novel heterozygous loss-of-function (LoF) (i.e. nonsense, frameshift and essential splice site mutations) and missense variants shared between father and daughter, and validated all LoF variants, and missense variants with a Combined Annotation Dependent Depletion (CADD) scaled score of ≥10. Genome-wide copy number analysis was performed on tumour tissue from both individuals to identify regions of LOH. RESULTS: Fifteen novel variants in 15 genes were shared by the father and daughter, including a nonsense mutation in REEP5. None of these germline variants were located in tumour regions of LOH shared by the father and daughter. Four genes (EXOG, RANBP2, RANBP6 and TNFRSF1B) harboured missense variants that fell in a region of LOH in the tumour from the father only, but none showed somatic loss of the wild type allele in the tumour. The REEP5 gene was sequenced in 23 individuals with presumed sporadic AMTs or PMP; no LoF or rare missense germline variants were identified. CONCLUSION: Germline exome sequencing of a father and daughter with AMTs identified novel candidate predisposing genes. Further studies are required to clarify the role of these genes in familial AMTs.


Subject(s)
Adenocarcinoma, Mucinous/genetics , Appendiceal Neoplasms/genetics , Exome , Germ-Line Mutation , Pseudomyxoma Peritonei/genetics , Adenocarcinoma, Mucinous/pathology , Adult , Aged , Appendiceal Neoplasms/pathology , Biomarkers, Tumor/genetics , Female , Follow-Up Studies , Humans , Loss of Heterozygosity , Male , Middle Aged , Pedigree , Prognosis , Pseudomyxoma Peritonei/pathology , Exome Sequencing
11.
Nucleic Acids Res ; 47(W1): W511-W515, 2019 07 02.
Article in English | MEDLINE | ID: mdl-31073612

ABSTRACT

RNA has become one of the major research topics in molecular biology. As a central player in key processes regulating gene expression, RNA is in the focus of many efforts to decipher the pathways that govern the transition of genetic information to a fully functional cell. As more and more researchers join this endeavour, there is a rapidly growing demand for comprehensive collections of tools that cover the diverse layers of RNA-related research. However, increasing amounts of data, from diverse types of experiments, addressing different aspects of biological questions need to be consolidated and integrated into a single framework. Only then is it possible to connect findings from e.g. RNA-Seq experiments and methods for e.g. target predictions. To address these needs, we present the RNA Workbench 2.0 , an updated online resource for RNA related analysis. With the RNA Workbench we created a comprehensive set of analysis tools and workflows that enables researchers to analyze their data without the need for sophisticated command-line skills. This update takes the established framework to the next level, providing not only a containerized infrastructure for analysis, but also a ready-to-use platform for hands-on training, analysis, data exploration, and visualization. The new framework is available at https://rna.usegalaxy.eu , and login is free and open to all users. The containerized version can be found at https://github.com/bgruening/galaxy-rna-workbench.


Subject(s)
RNA/chemistry , Software , High-Throughput Nucleotide Sequencing , Sequence Analysis, RNA
12.
Genome Med ; 9(1): 38, 2017 04 24.
Article in English | MEDLINE | ID: mdl-28438193

ABSTRACT

BACKGROUND: The increasing affordability of DNA sequencing has allowed it to be widely deployed in pathology laboratories. However, this has exposed many issues with the analysis and reporting of variants for clinical diagnostic use. Implementing a high-throughput sequencing (NGS) clinical reporting system requires a diverse combination of capabilities, statistical methods to identify variants, global variant databases, a validated bioinformatics pipeline, an auditable laboratory workflow, reproducible clinical assays and quality control monitoring throughout. These capabilities must be packaged in software that integrates the disparate components into a useable system. RESULTS: To meet these needs, we developed a web-based application, PathOS, which takes variant data from a patient sample through to a clinical report. PathOS has been used operationally in the Peter MacCallum Cancer Centre for two years for the analysis, curation and reporting of genetic tests for cancer patients, as well as the curation of large-scale research studies. PathOS has also been deployed in cloud environments allowing multiple institutions to use separate, secure and customisable instances of the system. Increasingly, the bottleneck of variant curation is limiting the adoption of clinical sequencing for molecular diagnostics. PathOS is focused on providing clinical variant curators and pathology laboratories with a decision support system needed for personalised medicine. While the genesis of PathOS has been within cancer molecular diagnostics, the system is applicable to NGS clinical reporting generally. CONCLUSIONS: The widespread availability of genomic sequencers has highlighted the limited availability of software to support clinical decision-making in molecular pathology. PathOS is a system that has been developed and refined in a hospital laboratory context to meet the needs of clinical diagnostics. The software is available as a set of Docker images and source code at https://github.com/PapenfussLab/PathOS .


Subject(s)
Clinical Laboratory Services , Genomics/methods , High-Throughput Nucleotide Sequencing/methods , Neoplasms/genetics , Software , Humans , Neoplasms/diagnosis , Precision Medicine , Sequence Analysis, DNA/methods
13.
Nat Commun ; 8: 14581, 2017 03 06.
Article in English | MEDLINE | ID: mdl-28262675

ABSTRACT

The Eµ-Myc mouse is an extensively used model of MYC driven malignancy; however to date there has only been partial characterization of MYC co-operative mutations leading to spontaneous lymphomagenesis. Here we sequence spontaneously arising Eµ-Myc lymphomas to define transgene architecture, somatic mutations, and structural alterations. We identify frequent disruptive mutations in the PRC1-like component and BCL6-corepressor gene Bcor. Moreover, we find unexpected concomitant multigenic lesions involving Cdkn2a loss and other cancer genes including Nras, Kras and Bcor. These findings challenge the assumed two-hit model of Eµ-Myc lymphoma and demonstrate a functional in vivo role for Bcor in suppressing tumorigenesis.


Subject(s)
B-Lymphocytes/metabolism , Gene Expression Regulation, Neoplastic , Lymphoma, B-Cell/genetics , Mutation , Proto-Oncogene Proteins c-myc/genetics , Repressor Proteins/genetics , Alleles , Animals , B-Lymphocytes/immunology , B-Lymphocytes/pathology , CRISPR-Cas Systems , Cyclin-Dependent Kinase Inhibitor p16/genetics , Cyclin-Dependent Kinase Inhibitor p16/immunology , Disease Models, Animal , Gene Editing , Gene Frequency , Janus Kinase 2/genetics , Janus Kinase 2/immunology , Lymphoma, B-Cell/immunology , Lymphoma, B-Cell/pathology , Mice , Mice, Transgenic , Proto-Oncogene Proteins c-myc/immunology , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/immunology , Repressor Proteins/immunology , STAT5 Transcription Factor/genetics , STAT5 Transcription Factor/immunology , Transcriptome , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/immunology , Whole Genome Sequencing
15.
Cancer Cell ; 30(1): 59-74, 2016 07 11.
Article in English | MEDLINE | ID: mdl-27374225

ABSTRACT

E proteins and their antagonists, the Id proteins, are transcriptional regulators important for normal hematopoiesis. We found that Id2 acts as a key regulator of leukemia stem cell (LSC) potential in MLL-rearranged acute myeloid leukemia (AML). Low endogenous Id2 expression is associated with LSC enrichment while Id2 overexpression impairs MLL-AF9-leukemia initiation and growth. Importantly, MLL-AF9 itself controls the E-protein pathway by suppressing Id2 while directly activating E2-2 expression, and E2-2 depletion phenocopies Id2 overexpression in MLL-AF9-AML cells. Remarkably, Id2 tumor-suppressive function is conserved in t(8;21) AML. Low expression of Id2 and its associated gene signature are associated with poor prognosis in MLL-rearranged and t(8;21) AML patients, identifying the Id2/E-protein axis as a promising new therapeutic target in AML.


Subject(s)
Inhibitor of Differentiation Protein 2/genetics , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Myeloid-Lymphoid Leukemia Protein/genetics , Oncogene Proteins, Fusion/genetics , Transcription Factor 7-Like 2 Protein/genetics , Translocation, Genetic , Animals , Cell Proliferation , Chromosomes, Human, Pair 21/genetics , Chromosomes, Human, Pair 8/genetics , Gene Expression Regulation, Leukemic , Humans , Inhibitor of Differentiation Protein 2/metabolism , Leukemia, Myeloid, Acute/metabolism , Mice , Myeloid-Lymphoid Leukemia Protein/metabolism , Neoplasms, Experimental , Oncogene Proteins, Fusion/metabolism , Prognosis , Stem Cells/cytology , Stem Cells/metabolism , Survival Analysis , Transcription Factor 7-Like 2 Protein/metabolism
16.
Oncotarget ; 6(35): 37663-77, 2015 Nov 10.
Article in English | MEDLINE | ID: mdl-26506417

ABSTRACT

Low grade serous ovarian tumours are a rare and under-characterised histological subtype of epithelial ovarian tumours, with little known of the molecular drivers and facilitators of tumorigenesis beyond classic oncogenic RAS/RAF mutations. With a move towards targeted therapies due to the chemoresistant nature of this subtype, it is pertinent to more fully characterise the genetic events driving this tumour type, some of which may influence response to therapy and/or development of drug resistance. We performed genome-wide high-resolution genomic copy number analysis (Affymetrix SNP6.0) and mutation hotspot screening (KRAS, BRAF, NRAS, HRAS, ERBB2 and TP53) to compare a large cohort of ovarian serous borderline tumours (SBTs, n = 57) with low grade serous carcinomas (LGSCs, n = 19). Whole exome sequencing was performed for 13 SBTs, nine LGSCs and one mixed low/high grade carcinoma. Copy number aberrations were detected in 61% (35/57) of SBTs, compared to 100% (19/19) of LGSCs. Oncogenic RAS/RAF/ERBB2 mutations were detected in 82.5% (47/57) of SBTs compared to 63% (12/19) of LGSCs, with NRAS mutations detected only in LGSC. Some copy number aberrations appeared to be enriched in LGSC, most significantly loss of 9p and homozygous deletions of the CDKN2A/2B locus. Exome sequencing identified BRAF, KRAS, NRAS, USP9X and EIF1AX as the most frequently mutated genes. We have identified markers of progression from borderline to LGSC and novel drivers of LGSC. USP9X and EIF1AX have both been linked to regulation of mTOR, suggesting that mTOR inhibitors may be a key companion treatment for targeted therapy trials of MEK and RAF inhibitors.


Subject(s)
Biomarkers, Tumor/genetics , Cystadenocarcinoma, Serous/genetics , Exome/genetics , Gene Expression Profiling , Genetic Variation/genetics , Ovarian Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Cystadenocarcinoma, Serous/pathology , Female , Follow-Up Studies , Humans , Middle Aged , Neoplasm Grading , Ovarian Neoplasms/pathology , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Young Adult
17.
Breast Cancer Res ; 17: 111, 2015 Aug 19.
Article in English | MEDLINE | ID: mdl-26283626

ABSTRACT

INTRODUCTION: PALB2 is emerging as a high-penetrance breast cancer predisposition gene in the order of BRCA1 and BRCA2. However, large studies that have evaluated the full gene rather than just the most common variants in both cases and controls are required before all truncating variants can be included in familial breast cancer variant testing. METHODS: In this study we analyse almost 2000 breast cancer cases sourced from individuals referred to familial cancer clinics, thus representing typical cases presenting in clinical practice. These cases were compared to a similar number of population-based cancer-free controls. RESULTS: We identified a significant excess of truncating variants in cases (1.3 %) versus controls (0.2 %), including six novel variants (p = 0.0001; odds ratio (OR) 6.58, 95 % confidence interval (CI) 2.3-18.9). Three of the four control individuals carrying truncating variants had at least one relative with breast cancer. There was no excess of missense variants in cases overall, but the common c.1676A > G variant (rs152451) was significantly enriched in cases and may represent a low-penetrance polymorphism (p = 0.002; OR 1.24 (95 % CI 1.09-1.47). CONCLUSIONS: Our findings support truncating variants in PALB2 as high-penetrance breast cancer susceptibility alleles, and suggest that a common missense variant may also lead to a low level of increased breast cancer risk.


Subject(s)
Mutation/genetics , Nuclear Proteins/genetics , Tumor Suppressor Proteins/genetics , Adult , Aged , Aged, 80 and over , Alleles , Australia , Breast Neoplasms/genetics , Case-Control Studies , Fanconi Anemia Complementation Group N Protein , Genetic Predisposition to Disease/genetics , Humans , Middle Aged , Prevalence , Risk , Young Adult
18.
BMC Med Genomics ; 8: 45, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-26231170

ABSTRACT

BACKGROUND: Loss of heterozygosity (LOH) is a common genetic event in cancer development, and is known to be involved in the somatic loss of wild-type alleles in many inherited cancer syndromes. The wider involvement of LOH in cancer is assumed to relate to unmasking a somatically mutated tumour suppressor gene through loss of the wild type allele. METHODS: We analysed 86 ovarian carcinomas for mutations in 980 genes selected on the basis of their location in common regions of LOH. RESULTS: We identified 36 significantly mutated genes, but these could only partly account for the quanta of LOH in the samples. Using our own and TCGA data we then evaluated five possible models to explain the selection for non-random accumulation of LOH in ovarian cancer genomes: 1. Classic two-hit hypothesis: high frequency biallelic genetic inactivation of tumour suppressor genes. 2. Epigenetic two-hit hypothesis: biallelic inactivation through methylation and LOH. 3. Multiple alternate-gene biallelic inactivation: low frequency gene disruption. 4. Haplo-insufficiency: Single copy gene disruption. 5. Modified two-hit hypothesis: reduction to homozygosity of low penetrance germline predisposition alleles. We determined that while high-frequency biallelic gene inactivation under model 1 is rare, regions of LOH (particularly copy-number neutral LOH) are enriched for deleterious mutations and increased promoter methylation, while copy-number loss LOH regions are likely to contain under-expressed genes suggestive of haploinsufficiency. Reduction to homozygosity of cancer predisposition SNPs may also play a minor role. CONCLUSION: It is likely that selection for regions of LOH depends on its effect on multiple genes. Selection for copy number neutral LOH may better fit the classic two-hit model whereas selection for copy number loss may be attributed to its effect on multi-gene haploinsufficiency. LOH mapping alone is unlikely to be successful in identifying novel tumour suppressor genes; a combined approach may be more effective.


Subject(s)
Loss of Heterozygosity , Ovarian Neoplasms/genetics , Female , Gene Dosage/genetics , Genes, Neoplasm/genetics , Genes, Tumor Suppressor , Genomics , Haploinsufficiency/genetics , Humans
19.
Genome Med ; 7(1): 87, 2015.
Article in English | MEDLINE | ID: mdl-26257827

ABSTRACT

BACKGROUND: Mucinous ovarian tumors are an unusual group of rare neoplasms with an apparently clear progression from benign to borderline to carcinoma, yet with a controversial cell of origin in the ovarian surface epithelium. They are thought to be molecularly distinct from other ovarian tumors but there have been no exome-level sequencing studies performed to date. METHODS: To understand the genetic etiology of mucinous ovarian tumors and assess the presence of novel therapeutic targets or pathways, we undertook exome sequencing of 24 tumors encompassing benign (5), borderline (8) and carcinoma (11) histologies and also assessed a validation cohort of 58 tumors for specific gene regions including exons 4-9 of TP53. RESULTS: The predominant mutational signature was of C>T transitions in a NpCpG context, indicative of deamination of methyl-cytosines. As well as mutations in known drivers (KRAS, BRAF and CDKN2A), we identified a high percentage of carcinomas with TP53 mutations (52 %), and recurrent mutations in RNF43, ELF3, GNAS, ERBB3 and KLF5. CONCLUSIONS: The diversity of mutational targets suggests multiple routes to tumorigenesis in this heterogeneous group of tumors that is generally distinct from other ovarian subtypes.

20.
Methods Mol Biol ; 1168: 83-98, 2014.
Article in English | MEDLINE | ID: mdl-24870132

ABSTRACT

Cancer is a complex disease driven by multiple mutations acquired over the lifetime of the cancer cells. These alterations, termed somatic mutations to distinguish them from inherited germline mutations, can include single-nucleotide substitutions, insertions, deletions, copy number alterations, and structural rearrangements. A patient's cancer can contain a combination of these aberrations, and the ability to generate a comprehensive genetic profile should greatly improve patient diagnosis and treatment. Next-generation sequencing has become the tool of choice to uncover multiple cancer mutations from a single tumor source, and the falling costs of this rapid high-throughput technology are encouraging its transition from basic research into a clinical setting. However, the detection of mutations in sequencing data is still an evolving area and cancer genomic data requires some special considerations. This chapter discusses these aspects and gives an overview of current bioinformatics methods for the detection of somatic mutations in cancer sequencing data.


Subject(s)
Computational Biology/methods , Genomics/methods , High-Throughput Nucleotide Sequencing/methods , Neoplasms/genetics , Humans
SELECTION OF CITATIONS
SEARCH DETAIL
...