ABSTRACT
The human Y chromosome has been notoriously difficult to sequence and assemble because of its complex repeat structure that includes long palindromes, tandem repeats and segmental duplications1-3. As a result, more than half of the Y chromosome is missing from the GRCh38 reference sequence and it remains the last human chromosome to be finished4,5. Here, the Telomere-to-Telomere (T2T) consortium presents the complete 62,460,029-base-pair sequence of a human Y chromosome from the HG002 genome (T2T-Y) that corrects multiple errors in GRCh38-Y and adds over 30 million base pairs of sequence to the reference, showing the complete ampliconic structures of gene families TSPY, DAZ and RBMY; 41 additional protein-coding genes, mostly from the TSPY family; and an alternating pattern of human satellite 1 and 3 blocks in the heterochromatic Yq12 region. We have combined T2T-Y with a previous assembly of the CHM13 genome4 and mapped available population variation, clinical variants and functional genomics data to produce a complete and comprehensive reference sequence for all 24 human chromosomes.
Subject(s)
Chromosomes, Human, Y , Genomics , Sequence Analysis, DNA , Humans , Base Sequence , Chromosomes, Human, Y/genetics , DNA, Satellite/genetics , Genetic Variation/genetics , Genetics, Population , Genomics/methods , Genomics/standards , Heterochromatin/genetics , Multigene Family/genetics , Reference Standards , Segmental Duplications, Genomic/genetics , Sequence Analysis, DNA/standards , Tandem Repeat Sequences/genetics , Telomere/geneticsABSTRACT
The Ensembl project (https://www.ensembl.org) annotates genomes and disseminates genomic data for vertebrate species. We create detailed and comprehensive annotation of gene structures, regulatory elements and variants, and enable comparative genomics by inferring the evolutionary history of genes and genomes. Our integrated genomic data are made available in a variety of ways, including genome browsers, search interfaces, specialist tools such as the Ensembl Variant Effect Predictor, download files and programmatic interfaces. Here, we present recent Ensembl developments including two new website portals. Ensembl Rapid Release (http://rapid.ensembl.org) is designed to provide core tools and services for genomes as soon as possible and has been deployed to support large biodiversity sequencing projects. Our SARS-CoV-2 genome browser (https://covid-19.ensembl.org) integrates our own annotation with publicly available genomic data from numerous sources to facilitate the use of genomics in the international scientific response to the COVID-19 pandemic. We also report on other updates to our annotation resources, tools and services. All Ensembl data and software are freely available without restriction.
Subject(s)
Computational Biology/methods , Databases, Nucleic Acid , Genomics/methods , SARS-CoV-2/genetics , Vertebrates/genetics , Animals , COVID-19/epidemiology , COVID-19/virology , Humans , Internet , Molecular Sequence Annotation/methods , Pandemics , Vertebrates/classificationABSTRACT
The GENCODE project annotates human and mouse genes and transcripts supported by experimental data with high accuracy, providing a foundational resource that supports genome biology and clinical genomics. GENCODE annotation processes make use of primary data and bioinformatic tools and analysis generated both within the consortium and externally to support the creation of transcript structures and the determination of their function. Here, we present improvements to our annotation infrastructure, bioinformatics tools, and analysis, and the advances they support in the annotation of the human and mouse genomes including: the completion of first pass manual annotation for the mouse reference genome; targeted improvements to the annotation of genes associated with SARS-CoV-2 infection; collaborative projects to achieve convergence across reference annotation databases for the annotation of human and mouse protein-coding genes; and the first GENCODE manually supervised automated annotation of lncRNAs. Our annotation is accessible via Ensembl, the UCSC Genome Browser and https://www.gencodegenes.org.
Subject(s)
COVID-19/prevention & control , Computational Biology/methods , Databases, Genetic , Genomics/methods , Molecular Sequence Annotation/methods , SARS-CoV-2/genetics , Animals , COVID-19/epidemiology , COVID-19/virology , Epidemics , Humans , Internet , Mice , Pseudogenes/genetics , RNA, Long Noncoding/genetics , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Transcription, Genetic/geneticsABSTRACT
Head and neck squamous cell cancer patients suffer from a high postoperative recurrence rate and poor prognosis. Thus, it is essential to better understand the underlying molecular mechanisms and identify the role of new biomarkers. Recent research has shown that the dysregulation of microRNAs is a potential biomarker as a screening or prognostic tool. Moreover, the literature reveals its promising usefulness to select the best treatment strategy and monitor tumour response. The purpose of this review is to identify and synthesize the available literature on microRNAs as biomarkers that could help manage patients with head and neck squamous cell cancer. A search in scientific databases was completed, including all relevant articles related to circulating microRNAs in head and neck squamous cell cancer published in English or Spanish. We focused on articles whose main findings were related to their usefulness in diagnosis and prognosis. Conclusion: Knowledge of microRNAs opens the possibilities that these molecules offer in terms of monitoring cancer disease in a less-invasive, simple manner, allowing for serial sampling to assess the response to treatment and minimal residual disease. It is yet to be determined whether liquid biopsy will replace the traditional biopsy in the future but it represents a change in the paradigm of management of head and neck squamous cell cancer.
Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , MicroRNAs , Humans , MicroRNAs/genetics , Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/genetics , Motivation , Biomarkers, Tumor/genetics , Squamous Cell Carcinoma of Head and Neck/genetics , PrognosisABSTRACT
We bring forward a case of a 58-year-old female who, undergoing treatment for glioblastoma with temozolomide and radiotherapy, visited the Emergency Department due to acute abdominal pain and chemotherapy-induced febrile neutropenia. She was diagnosed with sepsis due to phlegmonous gastritis. After several weeks in the Intensive Care Unit with antimicrobial coverage, our patient was discharged. Conceptually, phlegmonous gastritis is a highly unusual bacterial infection of the gastric wall. Intrinsically related to the alteration of the immune system, and frequently linked to cancer patients, its high morbidity and mortality and exceptional casuistry require early treatment and clinical suspicion.
Subject(s)
Gastritis , Neoplasms , Sepsis , Female , Humans , Middle Aged , Gastritis/complications , Sepsis/complicationsABSTRACT
We propose an algorithm for the early detection of cancer from a case of paraneoplastic syndrome.
Subject(s)
Intestinal Pseudo-Obstruction , Paraneoplastic Syndromes , Antibodies, Antinuclear , Chronic Disease , Humans , Intestinal Pseudo-Obstruction/diagnosis , Paraneoplastic Syndromes/diagnosis , PrognosisABSTRACT
BACKGROUND: AURA study reported 61% objective response rate and progression-free survival of 9.6 months with osimertinib in patients with EGFR/T790M+ non-small cell lung cancer. Due to lack of real-world data, we proposed this study to describe the experience with osimertinib in Spain. METHODS: Post-authorization, non-interventional Special Use Medication Program, multicenter, retrospective study in advanced EGFR/T790M+ non-small cell lung cancer. One hundred-fifty five patients were enrolled (August 2016-December 2018) from 30 sites. PRIMARY OBJECTIVE: progression-free survival. Secondary objectives: toxicity profile, objective response rate, and use of health service resources. RESULTS: 70% women, median age 66. 63.9% were non-smokers and 99% had adenocarcinoma. Most patients had received at least one prior treatment (97%), 91.7% had received previous EGFR-tyrosine kinase inhibitors and 2.8% osimertinib as first-line treatment. At data cutoff, median follow-up was 11.8 months. One hundred-fifty five patients were evaluable for response, 1.3% complete response, 40.6% partial response, 31% stable disease and 11.6% disease progression. Objective response rate was 42%. Median progression-free survival was 9.4 months. Of the 155 patients who received treatment, 76 (49%) did not reported any adverse event, 51% presented some adverse event, most of which were grade 1 or 2. The resource cost study indicates early use is warranted. CONCLUSION: This study to assess the real-world clinical impact of osimertinib showed high drug activity in pretreated advanced EGFR/T790M+ non-small cell lung cancer, with manageable adverse events. TRIAL REGISTRATION: Clinical trial registration number: NCT03790397 .
Subject(s)
Acrylamides/administration & dosage , Aniline Compounds/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/administration & dosage , Acrylamides/adverse effects , Adult , Aged , Aged, 80 and over , Aniline Compounds/adverse effects , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/mortality , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Female , Follow-Up Studies , Humans , Lung/pathology , Lung Neoplasms/diagnosis , Lung Neoplasms/genetics , Lung Neoplasms/mortality , Male , Middle Aged , Mutation , Neoplasm Staging , Progression-Free Survival , Protein Kinase Inhibitors/adverse effects , Retrospective Studies , Spain/epidemiologyABSTRACT
The accurate identification and description of the genes in the human and mouse genomes is a fundamental requirement for high quality analysis of data informing both genome biology and clinical genomics. Over the last 15 years, the GENCODE consortium has been producing reference quality gene annotations to provide this foundational resource. The GENCODE consortium includes both experimental and computational biology groups who work together to improve and extend the GENCODE gene annotation. Specifically, we generate primary data, create bioinformatics tools and provide analysis to support the work of expert manual gene annotators and automated gene annotation pipelines. In addition, manual and computational annotation workflows use any and all publicly available data and analysis, along with the research literature to identify and characterise gene loci to the highest standard. GENCODE gene annotations are accessible via the Ensembl and UCSC Genome Browsers, the Ensembl FTP site, Ensembl Biomart, Ensembl Perl and REST APIs as well as https://www.gencodegenes.org.
Subject(s)
Databases, Genetic , Genome, Human/genetics , Genomics , Pseudogenes/genetics , Animals , Computational Biology , Humans , Internet , Mice , Molecular Sequence Annotation , SoftwareABSTRACT
A 65-year-old woman who, in the context of dyspepsia and dismotility, was diagnosed with chronic intestinal pseudo-obstruction (CIPO) in small cell lung carcinoma (SCLC). In spite of a remarkable tumor response after the combination of chemotherapy and immunotherapy, an intestinal sepsis led to the patient's sudden death.
ABSTRACT
The Ensembl project (http://www.ensembl.org) provides genome information for sequenced chordate genomes with a particular focus on human, mouse, zebrafish and rat. Our resources include evidenced-based gene sets for all supported species; large-scale whole genome multiple species alignments across vertebrates and clade-specific alignments for eutherian mammals, primates, birds and fish; variation data resources for 17 species and regulation annotations based on ENCODE and other data sets. Ensembl data are accessible through the genome browser at http://www.ensembl.org and through other tools and programmatic interfaces.
Subject(s)
Databases, Genetic , Genomics , Animals , Gene Expression Regulation , Genetic Variation , Humans , Internet , Mice , Molecular Sequence Annotation , Rats , Software , Zebrafish/geneticsABSTRACT
The African buffalo (Syncerus caffer) is a wild bovid with a historical distribution across much of sub-Saharan Africa. Genomic analysis can provide insights into the evolutionary history of the species, and the key selective pressures shaping populations, including assessment of population level differentiation, population fragmentation, and population genetic structure. In this study we generated the highest quality de novo genome assembly (2.65 Gb, scaffold N50 69.17 Mb) of African buffalo to date, and sequenced a further 195 genomes from across the species distribution. Principal component and admixture analyses provided little support for the currently described four subspecies. Estimating Effective Migration Surfaces analysis suggested that geographical barriers have played a significant role in shaping gene flow and the population structure. Estimated effective population sizes indicated a substantial drop occurring in all populations 5-10,000 years ago, coinciding with the increase in human populations. Finally, signatures of selection were enriched for key genes associated with the immune response, suggesting infectious disease exert a substantial selective pressure upon the African buffalo. These findings have important implications for understanding bovid evolution, buffalo conservation and population management.
Subject(s)
Buffaloes , Genome , Genomics , Buffaloes/genetics , Animals , Genomics/methods , Gene Flow , Africa South of the Sahara , Genetics, Population , Phylogeny , Genetic VariationABSTRACT
Increased oxidative stress and indoleamine-2,3-dioxygenase (IDO) activity have been reported in cancer, but their relationship with chemotherapy remains unknown. The aim of the present study was to examine wether the chemotherapy treatments used in colorectal cancer had an additional effect on oxidative stress and on IDO activity. Plasma samples were collected from 27 colorectal cancer patients on cytostatic treatment, 27 with cytostatic drugs plus monoclonal antibodies (cytostatic-Mabs) and 15 non-treated patients. All patients with colorectal cancer had high plasma malondialdehyde (MDA), thioredoxin (Trx) levels, and elevated IDO activity in plasma (IDOp) and in dendritic cells (IDOc). This study shows that treatment with cytostatics have an effect on oxidative stress by increasing MDA levels and by decreasing Trx levels and IDO activity. However, treatment with cytostatic-Mabs showed no effect on MDA levels but decreased Trx levels, and the IDO activity showed values similar to the healthy group. Significant correlations between plasma IDO activity and the levels of Trx (r = 0.2062, p < 0.05) and MDA (r = 0.2873, p < 0.005) were observed. Furthermore, our study suggests that IDO activity measured as kynurenine levels could be used as a marker of the response to the chemotherapy treatments, although further studies are necessary.
Subject(s)
Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/blood , Indoleamine-Pyrrole 2,3,-Dioxygenase/blood , Thioredoxins/blood , Aged , Antineoplastic Agents/administration & dosage , Case-Control Studies , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/immunology , Drug Therapy , Female , Humans , Male , Malondialdehyde/blood , Middle Aged , Oxidative StressABSTRACT
OBJECTIVES: Concurrent chemoradiotherapy is the standard treatment for patients with unresectable, locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN); induction chemotherapy (ICT) may provide survival benefits in some patients. This study aimed to demonstrate the noninferiority of concomitant cetuximab plus radiotherapy (cet+RT) vs cisplatin plus radiotherapy (cis+RT) in patients with unresectable LA-SCCHN who were responsive to ICT. MATERIALS AND METHODS: This randomized, open-label, phase 3 trial studied patients with unresectable LA-SCCHN who received 3 cycles of ICT (docetaxel, cisplatin, and 5-fluorouracil; TPF) followed by cis+RT (standard arm) or cet+RT (experimental arm). The primary endpoint was noninferiority of the experimental arm vs the standard arm in terms of overall survival (OS), based on a hazard ratio (HR) of < 1.3. Secondary endpoints included progression-free survival, overall response, safety, and quality of life (QOL). RESULTS: Between July 15, 2008, and July 5, 2013, 519 patients were recruited and started ICT; 407 patients received post-ICT treatment (cis+RT, n = 205; cet+RT, n = 202). At a median follow-up of 43.9 (cis+RT) and 41.1 (cet+RT) months, median OS was 63.6 and 42.9 months with cis+RT and cet+RT, respectively (HR [90% CI] = 1.106 [0.888-1.378], P =.4492). There were no differences in progression-free survival, overall response rates, or adverse event rates between groups. There was greater late neurotoxicity with cis+RT than cet+RT (P =.0058). Several QOL dimensions improved with cet+RT vs cis+RT (physical functioning, P =.0287; appetite loss, P =.0248; social contact, P =.0153). CONCLUSION: Noninferiority of cet+RT over cis+RT was not demonstrated.
Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Squamous Cell/pathology , Cetuximab/therapeutic use , Chemoradiotherapy , Cisplatin , Docetaxel/therapeutic use , Fluorouracil , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/radiotherapy , Humans , Induction Chemotherapy/methods , Quality of Life , Squamous Cell Carcinoma of Head and Neck/drug therapy , Squamous Cell Carcinoma of Head and Neck/radiotherapy , TaxoidsABSTRACT
Tumor molecular profiling upon disease progression enables investigations of the tumor evolution. Next-generation sequencing (NGS) of liquid biopsies constitutes a noninvasive readily available source of tumor molecular information. In this study, 124 plasma samples from advanced EGFR-positive NSCLC patients, treated with a first-line EGFR tyrosine kinase inhibitor (EGFR-TKI) were collected upon disease progression. The circulating cell-free DNA (cfDNA) was sequenced using the Oncomine Pan-Cancer Cell-Free Assay™. Excluding EGFR mutations, the most frequently mutated gene was TP53 (57.3%), followed by APC (11.3%), FGFR3 (7.3%), and KRAS (5.6%). Different molecular alterations were observed upon disease progression depending on the location of the original EGFR-sensitizing mutation. Specifically, the detection of the p.T790M mutation was significantly associated with the presence of exon 19 mutations in EGFR (Fisher p-value: 0.028). All KRAS activating mutations (n = 8) were detected in tumors with EGFR mutations in exons 18 and 21 (Fisher p-value < 0.001). Similarly, mutations in NRAS and HRAS were more frequently detected in samples from tumors harboring mutations in exons 18 or 21 (Fisher p-value: 0.050 and Fisher p-value: 0.099, respectively). In conclusion, our data suggest that the mechanisms underlying EGFR-TKI resistance could be dependent on the exon location of the original EGFR-sensitizing mutation.
ABSTRACT
OBJECTIVES: To determine the incidence of ALK translocations in patients with advanced/metastatic NSCLC in Spain, to describe the clinical characteristics of these patients, and to evaluate the effectiveness and safety of treatment with crizotinib in a real-world setting. METHODS: This is an observational prospective and retrospective cohort study to determine the incidence of ALK translocations and to analyze the effectiveness and safety of crizotinib in a real-world setting. Patient characteristics, treatment patterns, time to best overall response, duration of treatment, objective response rates (ORR), rates of adverse events (AE), progression free survival (PFS) and overall survival (OS) were evaluated in the ALK study cohort of patients treated with crizotinib (prospective and retrospective). ALK incidence and quality of life (QoL) questionnaires were measured from patients included in the prospective cohort. RESULTS: The incidence of ALK translocations was 5.5 % (31 of 559 patients). Compared with ALK-negative patients, ALK-positive patients were significantly younger, predominantly female, and non-smokers. In the crizotinib effectiveness and safety study, 91 patients (42 prospective, 49 retrospective) with ALK-positive NSCLC (43.9 % in first-line, 56.1 % in second or more lines) were included. The ORR was 59.3 % and the median duration of response was 13.5 months (IQR, 5.3-26.2). The median PFS was 15.8 months (95 % CI, 11.8-22.3) and the median OS was 46.5 months, with 53 patients (58.2 %) still alive at data cut-off date. Frequently reported AEs included elevated transaminases, gastrointestinal disorders, and asthenia. Most patients (76.5 %) reported improved or stable scores for global QoL during treatment. CONCLUSIONS: The observed incidence of ALK translocations in NSCLC patients is aligned with published reports. This analysis of the real-world clinical experience in Spain confirms the therapeutic benefit and safety of crizotinib in advanced/metastatic ALK-positive NSCLC. CLINICALTRIALS: gov: NCT02679170.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Female , Male , Crizotinib/therapeutic use , Retrospective Studies , Quality of Life , Anaplastic Lymphoma Kinase/genetics , Prospective Studies , Spain/epidemiology , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Protein Kinase Inhibitors/adverse effects , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Transaminases/therapeutic useABSTRACT
PURPOSE: To determine the efficacy of the addition of gefitinib to raltitrexed in patients with colorectal cancer (CRC) that have progressed after first line chemotherapy. The study also sought to explore the safety of the combination and to investigate biomarkers predictive outcome. METHODS: A total of 76 patients were randomized to raltitrexed (3 mg/m(2) i.v.) every 21 days plus either daily gefitinib (250 mg p.o.) or placebo. The primary endpoint of the study was progression free survival (PFS). Tumor tissues were collected to determine the expression of EGFR, pEGFR, pMAPK, and pAkt. RESULTS: Both groups were well balanced with regard to prognostic factors. Treatment was well tolerated with no increased in toxicity except diarrhea and skin rash in the combination group. There were no differences in PFS between the combination arm [63 days (95% CI: 57-84)] compared to the raltitrexed alone arm [72 days (95% CI: 59-132)], or overall survival 361 days (95% CI: 283-533 days) versus 291 days (95% CI: 255-539 days) respectively. The objective response rate was 7.9% (3 patients) (CI 95%: 1,66-21,38) versus 5.3% (2 patients) (CI 0,64-17,75), respectively. The biomarker studies were not conclusive. CONCLUSION: The combination of raltitrexed and gefitinib was well tolerated although was not associated with improved progression free survival in patients with refractory CRC.
Subject(s)
Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Quinazolines/therapeutic use , Thiophenes/therapeutic use , Adolescent , Adult , Aged , Antineoplastic Agents/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Biomarkers, Tumor/metabolism , Demography , Female , Gefitinib , Humans , Male , Middle Aged , Quinazolines/adverse effects , Survival Analysis , Thiophenes/adverse effects , Treatment Outcome , Young AdultABSTRACT
To evaluate the KRAS, BRAF, EGFR, and HER2 gene status in colorectal cancer by novel techniques and evaluate whether anti-HER2 therapies could be offered in the treatment of these patients. There are conflicting data on the prevalence of BRAF mutations and EGFR and HER2 gene amplification in colorectal KRAS wild type patients. In our study we tried to evaluate these expressions and their relationship to future treatment assays. Clinical-pathological data and paraffin-embedded specimens were collected from 186 patients who underwent colorectal resections at General Yagüe Hospital in Burgos, Spain. KRAS and BRAF status was analyzed by real-time PCR in all patients. EGFR and HER2/NEU gene amplification was detected using fluorescent in situ hybridisation technique (FISH) in 38 KRAS and BRAF wild type patients. KRAS mutations were present in 48% of the colorectal cancer patients. BRAF mutations were present in 6.25% of the KRAS wild type patients. EGFR and HER2 gene amplification was observed in 5.3% and 26.3%, respectively, of KRAS and BRAF wild type colorectal cancer patients. HER2, but not EGFR gene amplification, was frequently observed in KRAS and BRAF wild type colorectal cancer patients. These data indicate that HER2 amplification could be one of the genes to be considered in the therapeutic management of colorectal cancer.
Subject(s)
Colorectal Neoplasms/ethnology , Colorectal Neoplasms/genetics , ErbB Receptors/biosynthesis , Gene Expression Regulation, Neoplastic , Proto-Oncogene Proteins B-raf/biosynthesis , Proto-Oncogene Proteins p21(ras)/biosynthesis , Receptor, ErbB-2/biosynthesis , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mutation , Retrospective Studies , SpainABSTRACT
The objective of the work was to study PIK3CA mutations in wild type KRAS and BRAF colorectal cancer. Clinicopathological data and paraffin-embedded specimens were collected on 73 patients who underwent colorectal resections at General Yagüe Hospital in Burgos. KRAS, BRAF and PIK3CA status were analyzed by real-time PCR in all patients. PIK3CA mutations were present in 8.22% of wild type KRAS and BRAF colorectal cancers. The most frequent mutation is E545K/D in exon 9 which represents 83.3% of all mutations. By contrast, we did not found any tumour harbouring H1047R mutation in exon 20. Among the patients who undergo a curative resection of colorectal cancer, PIK3CA mutation is present in an important percentage of KRAS and BRAF wild type tumours. PIK3CA mutation may be considered as it could be a hypothetic reason to be not responder to anti-EGFR antibodies.
Subject(s)
Colorectal Neoplasms/ethnology , Colorectal Neoplasms/genetics , Mutation , Phosphatidylinositol 3-Kinases/genetics , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins/genetics , ras Proteins/genetics , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Cetuximab , Class I Phosphatidylinositol 3-Kinases , Cohort Studies , ErbB Receptors/antagonists & inhibitors , Female , Humans , Male , Middle Aged , Proto-Oncogene Proteins p21(ras) , Retrospective Studies , SpainABSTRACT
The annotation of repetitive sequences within plant genomes can help in the interpretation of observed phenotypes. Moreover, repeat masking is required for tasks such as whole-genome alignment, promoter analysis, or pangenome exploration. Although homology-based annotation methods are computationally expensive, k-mer strategies for masking are orders of magnitude faster. Here, we benchmarked a two-step approach, where repeats were first called by k-mer counting and then annotated by comparison to curated libraries. This hybrid protocol was tested on 20 plant genomes from Ensembl, with the k-mer-based Repeat Detector (Red) and two repeat libraries (REdat, last updated in 2013, and nrTEplants, curated for this work). Custom libraries produced by RepeatModeler were also tested. We obtained repeated genome fractions that matched those reported in the literature but with shorter repeated elements than those produced directly by sequence homology. Inspection of the masked regions that overlapped genes revealed no preference for specific protein domains. Most Red-masked sequences could be successfully classified by sequence similarity, with the complete protocol taking less than 2 h on a desktop Linux box. A guide to curating your own repeat libraries and the scripts for masking and annotating plant genomes can be obtained at https://github.com/Ensembl/plant-scripts.
Subject(s)
Genome, Plant , Repetitive Sequences, Nucleic AcidABSTRACT
BACKGROUND: Survival data support the use of first-line osimertinib as the standard of care for epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC). However, it remains unclear whether upfront osimertinib is superior to sequential first- or second-generation tyrosine kinase inhibitors (TKIs) followed by osimertinib for all patients. It is impossible to predict which patients are at high risk of progression, and this constitutes a major limitation of the sequential TKI approach. PATIENTS AND METHODS: A total of 830 plasma samples from 228 patients with stage IV, EGFR-positive NSCLC who were treated with first-line TKIs were analysed by digital polymerase chain reaction (dPCR). RESULTS: The circulating tumour DNA (ctDNA) levels helped to identify patients with significantly improved survival rate, regardless of the treatment. Patients treated with first- or second-generation TKIs (N = 189) with EGFR mutations in plasma at a mutant allele frequency (MAF) <7% before treatment initiation (low-risk patients) or who were ctDNA negative after 3 or 6 months of treatment and with an MAF <7% at diagnosis (high responders) had two-thirds lower risk of death than patients in the opposite situation (adjusted hazard ratio [HR] = 0.38; 95% confidence interval [CI]: 0.23-0.64 and HR = 0.22; 95% CI: 0.12-0.42, respectively). The median overall survival (OS) for low-risk patients and high responders treated with first- or second-generation TKIs was 34.2 months and not reached, respectively, regardless of second-line treatment. There were no significant difference in OS between low-risk or high-responder patients treated upfront with osimertinib (N = 39) and those treated under a sequential approach with osimertinib (N = 60). Median OS was not reached in both cases. CONCLUSIONS: Pre-treatment ctDNA levels identify low-risk patients, who may benefit from sequential TKI treatment. Information regarding EGFR mutation clearance can help to improve patient selection.