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1.
Cell ; 176(3): 505-519.e22, 2019 01 24.
Article in English | MEDLINE | ID: mdl-30612738

ABSTRACT

Genomic instability can be a hallmark of both human genetic disease and cancer. We identify a deleterious UBQLN4 mutation in families with an autosomal recessive syndrome reminiscent of genome instability disorders. UBQLN4 deficiency leads to increased sensitivity to genotoxic stress and delayed DNA double-strand break (DSB) repair. The proteasomal shuttle factor UBQLN4 is phosphorylated by ATM and interacts with ubiquitylated MRE11 to mediate early steps of homologous recombination-mediated DSB repair (HRR). Loss of UBQLN4 leads to chromatin retention of MRE11, promoting non-physiological HRR activity in vitro and in vivo. Conversely, UBQLN4 overexpression represses HRR and favors non-homologous end joining. Moreover, we find UBQLN4 overexpressed in aggressive tumors. In line with an HRR defect in these tumors, UBQLN4 overexpression is associated with PARP1 inhibitor sensitivity. UBQLN4 therefore curtails HRR activity through removal of MRE11 from damaged chromatin and thus offers a therapeutic window for PARP1 inhibitor treatment in UBQLN4-overexpressing tumors.


Subject(s)
Carrier Proteins/genetics , Nuclear Proteins/genetics , Carrier Proteins/metabolism , Chromatin/metabolism , DNA , DNA Breaks, Double-Stranded , DNA Damage/genetics , DNA End-Joining Repair , DNA-Binding Proteins/metabolism , Female , Genomic Instability , Germ-Line Mutation , Homologous Recombination , Humans , MRE11 Homologue Protein/genetics , MRE11 Homologue Protein/metabolism , Male , Neoplasms/genetics , Neoplasms/metabolism , Nuclear Proteins/metabolism , Primary Cell Culture , Recombinational DNA Repair
2.
Proc Natl Acad Sci U S A ; 121(23): e2405771121, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38805295

ABSTRACT

The phylum Preplasmiviricota (kingdom Bamfordvirae, realm Varidnaviria) is a broad assemblage of diverse viruses with comparatively short double-stranded DNA genomes (<50 kbp) that produce icosahedral capsids built from double jelly-roll major capsid proteins. Preplasmiviricots infect hosts from all cellular domains, testifying to their ancient origin, and, in particular, are associated with six of the seven supergroups of eukaryotes. Preplasmiviricots comprise four major groups of viruses, namely, polintons, polinton-like viruses (PLVs), virophages, and adenovirids. We used protein structure modeling and analysis to show that protein-primed DNA polymerases (pPolBs) of polintons, virophages, and cytoplasmic linear plasmids encompass an N-terminal domain homologous to the terminal proteins (TPs) of prokaryotic PRD1-like tectivirids and eukaryotic adenovirids that are involved in protein-primed replication initiation, followed by a viral ovarian tumor-like cysteine deubiquitinylase (vOTU) domain. The vOTU domain is likely responsible for the cleavage of the TP from the large pPolB polypeptide and is inactivated in adenovirids, in which TP is a separate protein. Many PLVs and transpovirons encode a distinct derivative of polinton-like pPolB that retains the TP, vOTU, and pPolB polymerization palm domains but lacks the exonuclease domain and instead contains a superfamily 1 helicase domain. Analysis of the presence/absence and inactivation of the vOTU domains and replacement of pPolB with other DNA polymerases in eukaryotic preplasmiviricots enabled us to outline a complete scenario for their origin and evolution.


Subject(s)
Capsid Proteins , DNA Viruses , Capsid Proteins/metabolism , Capsid Proteins/chemistry , Capsid Proteins/genetics , DNA Viruses/genetics , Eukaryota/virology , Eukaryota/genetics , DNA-Directed DNA Polymerase/metabolism , DNA-Directed DNA Polymerase/chemistry , DNA-Directed DNA Polymerase/genetics , Models, Molecular , Phylogeny
3.
Proc Natl Acad Sci U S A ; 121(11): e2314606121, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38446847

ABSTRACT

Endogenous viral elements (EVEs) are common genetic passengers in various protists. Some EVEs represent viral fossils, whereas others are still active. The marine heterotrophic flagellate Cafeteria burkhardae contains several EVE types related to the virophage mavirus, a small DNA virus that parasitizes the lytic giant virus CroV. We hypothesized that endogenous virophages may act as an antiviral defense system in protists, but no protective effect of virophages in wild host populations has been shown so far. Here, we tested the activity of virophage EVEs and studied their impact on giant virus replication. We found that endogenous mavirus-like elements (EMALEs) from globally distributed Cafeteria populations produced infectious virus particles specifically in response to CroV infection. However, reactivation was stochastic, often inefficient, and poorly reproducible. Interestingly, only one of eight EMALE types responded to CroV infection, implying that other EMALEs may be linked to different giant viruses. We isolated and cloned several reactivated virophages and characterized their particles, genomes, and infection dynamics. All tested virophages inhibited the production of CroV during coinfection, thereby preventing lysis of the host cultures in a dose-dependent manner. Comparative genomics of different C. burkhardae strains revealed that inducible EMALEs are common and are not linked to specific geographic locations. We demonstrate that naturally occurring virophage EVEs reactivate upon giant virus infection, thus providing a striking example that eukaryotic EVEs can become active under specific conditions. Moreover, our results support the hypothesis that virophages can act as an adaptive antiviral defense system in protists.


Subject(s)
Giant Viruses , Stramenopiles , Virus Diseases , Humans , Virophages , Giant Viruses/genetics , Stramenopiles/genetics , Antiviral Agents
4.
Nucleic Acids Res ; 52(5): 2648-2671, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38180812

ABSTRACT

Telomerase-negative tumors maintain telomere length by alternative lengthening of telomeres (ALT), but the underlying mechanism behind ALT remains poorly understood. A proportion of aggressive neuroblastoma (NB), particularly relapsed tumors, are positive for ALT (ALT+), suggesting that a better dissection of the ALT mechanism could lead to novel therapeutic opportunities. TERRA, a long non-coding RNA (lncRNA) derived from telomere ends, localizes to telomeres in a R-loop-dependent manner and plays a crucial role in telomere maintenance. Here we present evidence that RNA modification at the N6 position of internal adenosine (m6A) in TERRA by the methyltransferase METTL3 is essential for telomere maintenance in ALT+ cells, and the loss of TERRA m6A/METTL3 results in telomere damage. We observed that m6A modification is abundant in R-loop enriched TERRA, and the m6A-mediated recruitment of hnRNPA2B1 to TERRA is critical for R-loop formation. Our findings suggest that m6A drives telomere targeting of TERRA via R-loops, and this m6A-mediated R-loop formation could be a widespread mechanism employed by other chromatin-interacting lncRNAs. Furthermore, treatment of ALT+ NB cells with a METTL3 inhibitor resulted in compromised telomere targeting of TERRA and accumulation of DNA damage at telomeres, indicating that METTL3 inhibition may represent a therapeutic approach for ALT+ NB.


Subject(s)
Methyltransferases , Neuroblastoma , RNA, Long Noncoding , Humans , Adenine/analogs & derivatives , Methyltransferases/metabolism , Neuroblastoma/drug therapy , Neuroblastoma/genetics , Neuroblastoma/metabolism , R-Loop Structures , RNA, Long Noncoding/metabolism , Telomere/genetics , Telomere Homeostasis
5.
Proc Natl Acad Sci U S A ; 120(16): e2300465120, 2023 04 18.
Article in English | MEDLINE | ID: mdl-37036967

ABSTRACT

Eukaryotic genomes contain a variety of endogenous viral elements (EVEs), which are mostly derived from RNA and ssDNA viruses that are no longer functional and are considered to be "genomic fossils." Genomic surveys of EVEs, however, are strongly biased toward animals and plants, whereas protists, which represent the majority of eukaryotic diversity, remain poorly represented. Here, we show that protist genomes harbor tens to thousands of diverse, ~14 to 40 kbp long dsDNA viruses. These EVEs, composed of virophages, Polinton-like viruses, and related entities, have remained hitherto hidden owing to poor sequence conservation between virus groups and their repetitive nature that precluded accurate short-read assembly. We show that long-read sequencing technology is ideal for resolving virus insertions. Many protist EVEs appear intact, and most encode integrases, which suggests that they have actively colonized hosts across the tree of eukaryotes. We also found evidence for gene expression in host transcriptomes and that closely related virophage and Polinton-like virus genomes are abundant in viral metagenomes, indicating that many EVEs are probably functional viruses.


Subject(s)
Eukaryota , Viruses , Animals , Eukaryota/genetics , DNA Viruses/genetics , Viruses/genetics , Virophages , Genome, Viral/genetics , Phylogeny
6.
J Theor Biol ; 579: 111716, 2024 02 21.
Article in English | MEDLINE | ID: mdl-38135033

ABSTRACT

Drug resistance is a major challenge for curative cancer treatment, representing the main reason of death in patients. Evolutionary biology suggests pauses between treatment rounds as a way to delay or even avoid resistance emergence. Indeed, this approach has already shown promising preclinical and early clinical results, and stimulated the development of mathematical models for finding optimal treatment protocols. Due to their complexity, however, these models do not lend themself to a rigorous mathematical analysis, hence so far clinical recommendations generally relied on numerical simulations and ad-hoc heuristics. Here, we derive two mathematical models describing tumour growth under genetic and epigenetic treatment resistance, respectively, which are simple enough for a complete analytical investigation. First, we find key differences in response to treatment protocols between the two modes of resistance. Second, we identify the optimal treatment protocol which leads to the largest possible tumour shrinkage rate. Third, we fit the "epigenetic model" to previously published xenograft experiment data, finding excellent agreement, underscoring the biological validity of our approach. Finally, we use the fitted model to calculate the optimal treatment protocol for this specific experiment, which we demonstrate to cause curative treatment, making it superior to previous approaches which generally aimed at stabilising tumour burden. Overall, our approach underscores the usefulness of simple mathematical models and their analytical examination, and we anticipate our findings to guide future preclinical and, ultimately, clinical research in optimising treatment regimes.


Subject(s)
Drug Resistance, Neoplasm , Neoplasms , Humans , Biological Evolution , Models, Theoretical , Neoplasms/drug therapy , Animals
7.
Eur J Anaesthesiol ; 41(10): 779-786, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39228239

ABSTRACT

BACKGROUND: For nearly 20 years, in international guidelines, mild therapeutic hypothermia (MTH) was an important component of postresuscitation care. However, recent randomised controlled trials have questioned its benefits. At present, international guidelines only recommend actively preventing fever, but there are ongoing discussions about whether the majority of cardiac arrest patients could benefit from MTH treatment. OBJECTIVE: The aim of this study was to compare the outcome of adult patients treated with and without MTH after cardiac arrest. DESIGN: Observational cohort study. SETTING: German Resuscitation Registry covering more than 31 million inhabitants of Germany and Austria. PATIENTS: All adult patients between 2006 and 2022 with out-of-hospital or in-hospital cardiac arrest and comatose on admission. MAIN OUTCOME MEASURES: Primary endpoint: hospital discharge with good neurological outcome [cerebral performance categories (CPC) 1 or 2]. Secondary endpoint: hospital discharge. We used a multivariate binary logistic regression analysis to identify the effects on outcome of all known influencing variables. RESULTS: We analysed 33 933 patients (10 034 treated with MTH, 23 899 without MTH). The multivariate regression model revealed that MTH was an independent predictor of CPC 1/2 survival and of hospital discharge with odds ratio (95% confidence intervals) of 1.60 (1.49 to 1.72), P < 0.001 and 1.89 (1.76 to 2.02), P < 0.001, respectively. CONCLUSION: Our data indicate the existence of a positive association between MTH and a favourable neurological outcome after cardiac arrest. It therefore seems premature to refrain from giving MTH treatment for the entire spectrum of patients after cardiac arrest. Further prospective studies are needed.


Subject(s)
Heart Arrest , Hypothermia, Induced , Registries , Humans , Male , Female , Hypothermia, Induced/methods , Middle Aged , Aged , Heart Arrest/therapy , Heart Arrest/mortality , Treatment Outcome , Cohort Studies , Randomized Controlled Trials as Topic , Germany/epidemiology , Austria/epidemiology , Patient Discharge , Aged, 80 and over , Coma/therapy , Coma/mortality , Out-of-Hospital Cardiac Arrest/therapy , Out-of-Hospital Cardiac Arrest/mortality
8.
Br J Cancer ; 128(8): 1559-1571, 2023 04.
Article in English | MEDLINE | ID: mdl-36807339

ABSTRACT

BACKGROUND: Genomic alterations of the anaplastic lymphoma kinase gene (ALK) occur recurrently in neuroblastoma, a pediatric malignancy of the sympathetic nervous system. However, information on their development over time has remained sparse. METHODS: ALK alterations were assessed in neuroblastomas at diagnosis and/or relapse from a total of 943 patients, covering all stages of disease. Longitudinal information on diagnostic and relapsed samples from individual patients was available in 101 and 102 cases for mutation and amplification status, respectively. RESULTS: At diagnosis, ALK point mutations occurred in 10.5% of all cases, with highest frequencies in stage 4 patients <18 months. At relapse, ALK alteration frequency increased by 70%, both in high-risk and non-high-risk cases. The increase was most likely due to de novo mutations, frequently leading to R1275Q substitutions, which are sensitive to pharmacological ALK inhibition. By contrast, the frequency of ALK amplifications did not change over the course of the disease. ALK amplifications, but not mutations, were associated with poor patient outcome. CONCLUSIONS: The considerably increased frequency of ALK mutations at relapse and their high prevalence in young stage 4 patients suggest surveying the genomic ALK status regularly in these patient cohorts, and to evaluate ALK-targeted treatment also in intermediate-risk patients.


Subject(s)
Neuroblastoma , Receptor Protein-Tyrosine Kinases , Child , Humans , Anaplastic Lymphoma Kinase/genetics , Receptor Protein-Tyrosine Kinases/genetics , Neoplasm Recurrence, Local/genetics , Neuroblastoma/genetics , Neuroblastoma/pathology , Genomics
9.
J Theor Biol ; 557: 111327, 2023 01 21.
Article in English | MEDLINE | ID: mdl-36341757

ABSTRACT

Differentiated cancer cells may regain stem cell characteristics; however, the effects of such a cellular dedifferentiation on tumoural growth and treatment are currently understudied. Thus, we here extend a mathematical model of cancer stem cell (CSC) driven tumour growth to also include dedifferentiation. We show that dedifferentiation increases the likelihood of tumorigenesis and the speed of tumoural growth, both modulated by the proliferative potential of the non-stem cancer cells (NSCCs). We demonstrate that dedifferentiation also may lead to treatment evasion, especially when a treatment solely targets CSCs. Conversely, targeting both CSCs and NSCCs in parallel is shown to be more robust to dedifferentiation. Despite dedifferentiation, perturbing CSC-related parameters continues to exert the largest relative effect on tumoural growth; however, we show the existence of synergies between specific CSC- and NSCC-directed treatments which cause superadditive reductions of tumoural growth. Overall, our study demonstrates various effects of dedifferentiation on growth and treatment of tumoural lesions, and we anticipate our results to be helpful in guiding future molecular and clinical research on limiting tumoural growth in vivo.


Subject(s)
Neoplasms , Humans , Neoplasms/therapy , Carcinogenesis , Cell Transformation, Neoplastic , Neoplastic Stem Cells , Probability
10.
Arch Virol ; 168(11): 283, 2023 Oct 31.
Article in English | MEDLINE | ID: mdl-37904060

ABSTRACT

Large DNA viruses in the phylum Nucleocytoviricota, sometimes referred to as "giant viruses" owing to their large genomes and virions, have been the subject of burgeoning interest over the last decade. Here, we describe recently adopted taxonomic updates for giant viruses within the order Imitervirales. The families Allomimiviridae, Mesomimiviridae, and Schizomimiviridae have been created to accommodate the increasing diversity of mimivirus relatives that have sometimes been referred to in the literature as "extended Mimiviridae". In addition, the subfamilies Aliimimivirinae, Megamimivirinae, and Klosneuvirinae have been established to refer to subgroups of the Mimiviridae. Binomial names have also been adopted for all recognized species in the order. For example, Acanthamoeba polyphaga mimivirus is now classified in the species Mimivirus bradfordmassiliense.


Subject(s)
Giant Viruses , Mimiviridae , Humans , Giant Viruses/genetics , DNA Viruses/genetics , Mimiviridae/genetics , Genome, Viral , Virion
11.
Mol Cancer ; 21(1): 126, 2022 06 10.
Article in English | MEDLINE | ID: mdl-35689207

ABSTRACT

BACKGROUND: Development of resistance to targeted therapies has tempered initial optimism that precision oncology would improve poor outcomes for cancer patients. Resistance mechanisms, however, can also confer new resistance-specific vulnerabilities, termed collateral sensitivities. Here we investigated anaplastic lymphoma kinase (ALK) inhibitor resistance in neuroblastoma, a childhood cancer frequently affected by activating ALK alterations. METHODS: Genome-wide forward genetic CRISPR-Cas9 based screens were performed to identify genes associated with ALK inhibitor resistance in neuroblastoma cell lines. Furthermore, the neuroblastoma cell line NBLW-R was rendered resistant by continuous exposure to ALK inhibitors. Genes identified to be associated with ALK inhibitor resistance were further investigated by generating suitable cell line models. In addition, tumor and liquid biopsy samples of four patients with ALK-mutated neuroblastomas before ALK inhibitor treatment and during tumor progression under treatment were genomically profiled. RESULTS: Both genome-wide CRISPR-Cas9-based screens and preclinical spontaneous ALKi resistance models identified NF1 loss and activating NRASQ61K mutations to confer resistance to chemically diverse ALKi. Moreover, human neuroblastomas recurrently developed de novo loss of NF1 and activating RAS mutations after ALKi treatment, leading to therapy resistance. Pathway-specific perturbations confirmed that NF1 loss and activating RAS mutations lead to RAS-MAPK signaling even in the presence of ALKi. Intriguingly, NF1 loss rendered neuroblastoma cells hypersensitive to MEK inhibition. CONCLUSIONS: Our results provide a clinically relevant mechanistic model of ALKi resistance in neuroblastoma and highlight new clinically actionable collateral sensitivities in resistant cells.


Subject(s)
Neuroblastoma , Precision Medicine , Anaplastic Lymphoma Kinase/genetics , Cell Line, Tumor , Child , Humans , Mutation , Neuroblastoma/drug therapy , Neuroblastoma/genetics , Neuroblastoma/pathology , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Signal Transduction
12.
Bioinformatics ; 36(22-23): 5514-5515, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33258916

ABSTRACT

MOTIVATION: The generation of high-quality assemblies, even for large eukaryotic genomes, has become a routine task for many biologists thanks to recent advances in sequencing technologies. However, the annotation of these assemblies-a crucial step toward unlocking the biology of the organism of interest-has remained a complex challenge that often requires advanced bioinformatics expertise. RESULTS: Here, we present MOSGA (Modular Open-Source Genome Annotator), a genome annotation framework for eukaryotic genomes with a user-friendly web-interface that generates and integrates annotations from various tools. The aggregated results can be analyzed with a fully integrated genome browser and are provided in a format ready for submission to NCBI. MOSGA is built on a portable, customizable and easily extendible Snakemake backend, and thus, can be tailored to a wide range of users and projects. AVAILABILITY AND IMPLEMENTATION: We provide MOSGA as a web service at https://mosga.mathematik.uni-marburg.de and as a docker container at registry.gitlab.com/mosga/mosga: latest. Source code can be found at https://gitlab.com/mosga/mosga. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Genome , Software , Eukaryota
13.
Nature ; 540(7632): 288-291, 2016 12 07.
Article in English | MEDLINE | ID: mdl-27929021

ABSTRACT

Endogenous viral elements are increasingly found in eukaryotic genomes, yet little is known about their origins, dynamics, or function. Here we provide a compelling example of a DNA virus that readily integrates into a eukaryotic genome where it acts as an inducible antiviral defence system. We found that the virophage mavirus, a parasite of the giant Cafeteria roenbergensis virus (CroV), integrates at multiple sites within the nuclear genome of the marine protozoan Cafeteria roenbergensis. The endogenous mavirus is structurally and genetically similar to eukaryotic DNA transposons and endogenous viruses of the Maverick/Polinton family. Provirophage genes are not constitutively expressed, but are specifically activated by superinfection with CroV, which induces the production of infectious mavirus particles. Virophages can inhibit the replication of mimivirus-like giant viruses and an anti-viral protective effect of provirophages on their hosts has been hypothesized. We find that provirophage-carrying cells are not directly protected from CroV; however, lysis of these cells releases infectious mavirus particles that are then able to suppress CroV replication and enhance host survival during subsequent rounds of infection. The microbial host-parasite interaction described here involves an altruistic aspect and suggests that giant-virus-induced activation of provirophages might be ecologically relevant in natural protist populations.


Subject(s)
Genome/genetics , Giant Viruses/physiology , Host-Parasite Interactions , Stramenopiles/genetics , Stramenopiles/virology , Virophages/growth & development , Virus Integration , DNA Transposable Elements/genetics , Gene Expression Regulation, Viral , Genome, Viral/genetics , Giant Viruses/genetics , Giant Viruses/growth & development , Mimiviridae/growth & development , Prophages/genetics , Prophages/physiology , Stramenopiles/growth & development , Superinfection , Virion/growth & development , Virophages/genetics , Virus Release , Virus Replication
14.
BMC Emerg Med ; 22(1): 158, 2022 09 10.
Article in English | MEDLINE | ID: mdl-36085024

ABSTRACT

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) due to trauma is rare, and survival in this group is infrequent. Over the last decades, several new procedures have been implemented to increase survival, and a "Special circumstances chapter" was included in the European Resuscitation Council (ERC) guidelines in 2015. This article analysed outcomes after traumatic cardiac arrest in Germany using data from the German Resuscitation Registry (GRR) and the TraumaRegister DGU® (TR-DGU) of the German Trauma Society.  METHODS: In this study, data from patients with OHCA between 01.01.2014 and 31.12.2019 secondary to major trauma and where cardiopulmonary resuscitation (CPR) was started were eligible for inclusion. Endpoints were return of spontaneous circulation (ROSC), hospital admission with ROSC and survival to hospital discharge. RESULTS: 1.049 patients were eligible for inclusion. ROSC was achieved in 28.7% of the patients, 240 patients (22.9%) were admitted to hospital with ROSC and 147 (14.0%) with ongoing CPR. 643 (67.8%) patients were declared dead on scene. Of all patients resuscitated after traumatic OHCA, 27.3% (259) died in hospital. The overall mortality was 95.0% and 5.0% survived to hospital discharge (47). In a multivariate logistic regression analysis; age, sex, injury severity score (ISS), head injury, found in cardiac arrest, shock on admission, blood transfusion, CPR in emergency room (ER), emergency surgery and initial electrocardiogram (ECG), were independent predictors of mortality. CONCLUSION: Traumatic cardiac arrest was an infrequent event with low overall survival. The mortality has remained unchanged over the last decades in Germany. Additional efforts are necessary to identify reversible cardiac arrest causes and provide targeted trauma resuscitation on scene. TRIAL REGISTRATION: DRKS, DRKS-ID DRKS00027944. Retrospectively registered 03/02/2022.


Subject(s)
Cardiopulmonary Resuscitation , Out-of-Hospital Cardiac Arrest , Cardiopulmonary Resuscitation/methods , Germany/epidemiology , Humans , Injury Severity Score , Out-of-Hospital Cardiac Arrest/therapy , Registries
15.
Lancet Oncol ; 22(12): 1764-1776, 2021 12.
Article in English | MEDLINE | ID: mdl-34780709

ABSTRACT

BACKGROUND: Several paediatric malignancies, including anaplastic large cell lymphoma (ALCL), inflammatory myofibroblastic tumour (IMT), neuroblastoma, and rhabdomyosarcoma, harbour activation of anaplastic lymphoma kinase (ALK) through different mechanisms. Here, we report the safety, pharmacokinetics, and efficacy of ceritinib in paediatric patients with ALK-positive malignancies. METHODS: This multicentre, open-label, phase 1 trial was done at 23 academic hospitals in ten countries. Children (aged ≥12 months to <18 years) diagnosed with locally advanced or metastatic ALK-positive malignancies that had progressed despite standard therapy, or for which no effective standard therapy were available, were eligible. ALK-positive malignancies were defined as those with ALK rearrangement, amplification, point mutation, or in the case of rhabdomyosarcoma, expression in the absence of any genetic alteration. Eligible patients had evaluable or measurable disease as defined by either Response Evaluation Criteria in Solid Tumours, version 1.1 for patients with non-haematological malignancies, International Neuroblastoma Response Criteria scan for patients with neuroblastoma, or International Working Group criteria for patients with lymphoma. Other eligibility criteria were Karnofsky performance status score of at least 60% for patients older than 12 years or Lansky score of at least 50% for patients aged 12 years or younger. This study included a dose-escalation part, followed by a dose-expansion part, in which all patients received treatment at the recommended dose for expansion (RDE) established in the dose-escalation part. Both parts of the study were done in fasted and fed states. In the dose-escalation part, patients were treated with once-daily ceritinib orally, with dose adjusted for body-surface area, rounded to the nearest multiple of the 50 mg dose strength. The starting dose in the fasted state was 300 mg/m2 daily and for the fed state was 320 mg/m2 daily. The primary objective of this study was to establish the maximum tolerated dose (ie, RDE) of ceritinib in the fasted and fed states. The RDE was established on the basis of the incidence of dose-limiting toxicities in patients who completed a minimum of 21 days of treatment with safety assessments and at least 75% drug exposure, or who discontinued treatment earlier because of dose-limiting toxicity. Overall response rate (defined as the proportion of patients with a best overall response of complete response or partial response) was a secondary endpoint. Activity and safety analyses were done in all patients who received at least one dose of ceritinib. This trial is registered with ClinicalTrials.gov (NCT01742286) and is completed. FINDINGS: Between Aug 28, 2013, and Oct 17, 2017, 83 children with ALK-positive malignancies were enrolled to the dose-escalation (n=40) and dose-expansion (n=43) groups. The RDE of ceritinib was established as 510 mg/m2 (fasted) and 500 mg/m2 (fed). 55 patients (30 with neuroblastoma, ten with IMT, eight with ALCL, and seven with other tumour types) were treated with ceritinib at the RDE (13 patients at 510 mg/m2 fasted and 42 patients at 500 mg/m2 fed). The median follow-up was 33·3 months (IQR 24·8-39·3) for patients with neuroblastoma, 33·2 months (27·9-35·9) for those with IMT, 34·0 months (21·9-46·4) for those with ALCL, and 27·5 months (22·4-36·9) for patients with other tumour types. An overall response was recorded in six (20%; 95% CI 8-39) of 30 patients with neuroblastoma, seven (70%; 33-93) of ten patients with IMT, six (75%; 35-97) of eight patients with ALCL, and one (14%; <1-58) of seven patients with other tumours. The safety profile of ceritinib was consistent with that observed in adult patients. All patients had at least one adverse event. Grade 3 or 4 adverse events occurred in 67 (81%) of 83 patients and were mostly increases in aminotransferases (alanine aminotransferase increase in 38 [46%] patients and aspartate aminotransferase increase in 27 [33%] patients). At least one serious adverse event was reported in 40 (48%) of 83 patients and 31 (37%) of 83 patients had at least one grade 3 or 4 serious adverse event. 14 (17%) deaths occurred during the study, of which 12 were on-treatment deaths and two were after 30 days of the last dose. Of the 12 on-treatment deaths, ten were due to disease progression (neuroblastoma), one due to sepsis, and one due to intractable hypotension. INTERPRETATION: Ceritinib 500 mg/m2 once daily with food is the recommended dose for paediatric patients with ALK-positive malignancies. Ceritinib showed promising preliminary antitumour activity in patients with ALK-positive refractory or recurrent IMT or ALCL, and in a subset of patients with relapsed or refractory neuroblastoma, with a manageable safety profile. Our data support the notion that ALK inhibitors should be considered in therapeutic strategies for paediatric patients with malignancies with genetic ALK alterations. FUNDING: Novartis Pharmaceutical Corporation.


Subject(s)
Anaplastic Lymphoma Kinase/metabolism , Neoplasms/drug therapy , Pyrimidines/therapeutic use , Sulfones/therapeutic use , Adolescent , Anaplastic Lymphoma Kinase/genetics , Antineoplastic Agents/therapeutic use , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Male , Maximum Tolerated Dose , Mutation , Neoplasms/metabolism , Neoplasms/pathology , Prognosis , Survival Rate
16.
Curr Issues Mol Biol ; 40: 1-24, 2021.
Article in English | MEDLINE | ID: mdl-32089519

ABSTRACT

Double-stranded (ds) DNA viruses of the family Lavidaviridae, commonly known as virophages, are a fascinating group of eukaryotic viruses that depend on a coinfecting giant dsDNA virus of the Mimiviridae for their propagation. Instead of replicating in the nucleus, virophages multiply in the cytoplasmic virion factory of a coinfecting giant virus inside a phototrophic or heterotrophic protistal host cell. Virophages are parasites of giant viruses and can inhibit their replication, which may lead to increased survival rates of the infected host cell population. The genomes of virophages are 17-33 kilobase pairs (kbp) long and encode 16-34 proteins. Genetic signatures of virophages can be found in metagenomic datasets from various saltwater and freshwater environments around the planet. Most virophages share a set of conserved genes that code for a major and a minor capsid protein, a cysteine protease, a genome-packaging ATPase, and a superfamily 3 helicase, although the genomes are otherwise diverse and variable. Lavidaviruses share genes with other mobile genetic elements, suggesting that horizontal gene transfer and recombination have been major forces in shaping these viral genomes. Integrases are occasionally found in virophage genomes and enable these DNA viruses to persist as provirophages in the chromosomes of their viral and cellular hosts. As we watch the genetic diversity of this new viral family unfold through metagenomics, additional isolates are still lacking and critical questions regarding their infection cycle, host range, and ecology remain to be answered.


Subject(s)
Genetic Variation , Genome, Viral , Metagenome , Virophages/classification , Virophages/genetics , Capsid/chemistry , Coinfection , DNA, Viral/genetics , Evolution, Molecular , Gene Transfer, Horizontal , Giant Viruses/classification , Giant Viruses/genetics , Host Microbial Interactions , Host Specificity , Metagenomics/methods , Phylogeny , Virus Replication
17.
Pediatr Blood Cancer ; 68(8): e29038, 2021 08.
Article in English | MEDLINE | ID: mdl-33826231

ABSTRACT

INTRODUCTION: The survival of children with stage 4(M) neuroblastoma without MYCN amplification and below the age of 18 months is considered better than the still dismal outcome of older high-risk neuroblastoma patients. This study analyzes the impact of clinical and molecular characteristics on the long-term outcome. PATIENTS AND METHODS: Clinical presentation, survival, and recurrence patterns of patients enrolled onto trials NB90, NB97, and NB2004 were retrospectively analyzed. Gene expression signatures based on RNA microarrays (TH10) were investigated if tumor material was available. RESULTS: Between 1990 and 2015, 177 patients with stage 4(M) MYCN nonamplified neuroblastoma aged less than 18 months at diagnosis were eligible. After a median follow-up of 9.7 years (IQR 5.0, 13.4), the proportions of 10-year event-free survival (EFS) and overall survival (OS) were 73% (95% confidence interval [CI] 67-79%) and 86% (95% CI 80-92%), respectively. Of the 27 neuroblastoma recurrences, 44% occurred in more than one site. Four additional patients presented histologically mature ganglioneuroma at recurrence. Six patients developed a secondary malignancy. The secondary 5-year EFS and OS of the 27 patients with neuroblastoma recurrence were 44% and 59%, respectively. TH10 gene expression signature was not prognostically predictive in the investigated subcohort. CONCLUSION: The outcome of patients with stage 4(M) neuroblastoma aged less than 18 months is favorable when treated with high-risk or otherwise intensive therapy. The development of secondary malignancies and the potential of maturation to ganglioneuroma call for a controlled stepwise reduction of treatment intensity.


Subject(s)
Ganglioneuroma , Neuroblastoma , Disease-Free Survival , Ganglioneuroma/genetics , Ganglioneuroma/pathology , Gene Amplification , Humans , Infant , N-Myc Proto-Oncogene Protein/genetics , Neoplasm Staging , Neuroblastoma/genetics , Neuroblastoma/pathology , Prognosis , Retrospective Studies
18.
Proc Natl Acad Sci U S A ; 115(28): 7332-7337, 2018 07 10.
Article in English | MEDLINE | ID: mdl-29941605

ABSTRACT

Virophages have the unique property of parasitizing giant viruses within unicellular hosts. Little is understood about how they form infectious virions in this tripartite interplay. We provide mechanistic insights into assembly and maturation of mavirus, a marine virophage, by combining structural and stability studies on capsomers, virus-like particles (VLPs), and native virions. We found that the mavirus protease processes the double jelly-roll (DJR) major capsid protein (MCP) at multiple C-terminal sites and that these sites are conserved among virophages. Mavirus MCP assembled in Escherichia coli in the absence and presence of penton protein, forming VLPs with defined size and shape. While quantifying VLPs in E. coli lysates, we found that full-length rather than processed MCP is the competent state for capsid assembly. Full-length MCP was thermally more labile than truncated MCP, and crystal structures of both states indicate that full-length MCP has an expanded DJR core. Thus, we propose that the MCP C-terminal domain serves as a scaffolding domain by adding strain on MCP to confer assembly competence. Mavirus protease processed MCP more efficiently after capsid assembly, which provides a regulation mechanism for timing capsid maturation. By analogy to Sputnik and adenovirus, we propose that MCP processing renders mavirus particles infection competent by loosening interactions between genome and capsid shell and destabilizing pentons for genome release into host cells. The high structural similarity of mavirus and Sputnik capsid proteins together with conservation of protease and MCP processing suggest that assembly and maturation mechanisms described here are universal for virophages.


Subject(s)
Capsid Proteins , Peptide Hydrolases , Virion , Virophages , Virus Assembly/physiology , Capsid Proteins/chemistry , Capsid Proteins/genetics , Capsid Proteins/metabolism , Peptide Hydrolases/chemistry , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , Virion/chemistry , Virion/genetics , Virion/metabolism , Virophages/chemistry , Virophages/physiology
19.
Postepy Dermatol Alergol ; 38(2): 14-20, 2021 Feb.
Article in English | MEDLINE | ID: mdl-34408561

ABSTRACT

Keratinization means cytodifferentiation of keratinocytes turning into corneocytes in the stratum corneum. Disorders of keratinization (hyperkeratosis, parakeratosis and dyskeratosis) are causing many dermatological diseases, including various types of ichthyoses, pachyonychia congenita, pityriasis rubra pilaris, all subtypes of psoriasis, pityriasis lichenoides, dyskeratosis congenita, leukoplakia and keratosis follicularis, which apart from skin lesions may affect the eye's adnexae causing ectropion, entropion, blepharitis, madarosis, and trichiasis, the ocular surface causing keratitis, conjunctivitis, corneal ulceration and episcleritis, which in turn cause uveitis and various fundoscopic changes (proliferative retinopathy, retinal vasculopathy, macular oedema and birdshot chorioretinopathy). Knowledge of ocular symtoms associated with pathological keratinization is crucial, preventing sight-threatening complications such as corneal perforation, lagophthalmus, phthisis bulbi, retinal neovascularization, retinal vasculopathy and optic nerve atrophy. This review encourages dermatologists to monitor patients for ocular symptoms and encourage ophthalmologists to monitor patients for dermatological symptoms.

20.
Cytogenet Genome Res ; 160(11-12): 659-663, 2020.
Article in English | MEDLINE | ID: mdl-33472199

ABSTRACT

The 22q11.2 microduplication syndrome shows variable phenotypes with reduced penetrance compared to the 22q11.2 deletion syndrome. We report a woman with overgrowth and macrocephaly, mild mental retardation, heart defect, kidney anomalies, and dysmorphic features. Array-CGH analysis revealed a 246-kb duplication at the 22q11.2 region. No additional clinically significant CNVs were found. The case resembles a previously published case also showing overgrowth and macrocephaly with an almost identical 22q11.2 duplication of 252 kb.


Subject(s)
Abnormalities, Multiple/genetics , Abnormalities, Multiple/pathology , Chromosome Duplication/genetics , DiGeorge Syndrome/genetics , DiGeorge Syndrome/pathology , Genetic Testing , Adolescent , Adult , Child , Chromosomes, Human, Pair 22/genetics , Chromosomes, Human, Pair 8/genetics , DNA Copy Number Variations , Female , Humans , Infant , Male , Pedigree , Phenotype , Syndrome
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