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1.
Res Sq ; 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38883758

ABSTRACT

A deep learning model using attention-based multiple instance learning (aMIL) and self-supervised learning (SSL) was developed to perform pathologic classification of neuroblastic tumors and assess MYCN-amplification status using H&E-stained whole slide digital images. The model demonstrated strong performance in identifying diagnostic category, grade, mitosis-karyorrhexis index (MKI), and MYCN-amplification on an external test dataset. This AI-based approach establishes a valuable tool for automating diagnosis and precise classification of neuroblastoma tumors.

2.
bioRxiv ; 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38895399

ABSTRACT

Tumor cell heterogeneity in neuroblastoma, a pediatric cancer arising from neural crest-derived progenitor cells, poses a significant clinical challenge. In particular, unlike adrenergic (ADRN) neuroblastoma cells, mesenchymal (MES) cells are resistant to chemotherapy and retinoid therapy and thereby significantly contribute to relapses and treatment failures. Previous research suggested that overexpression or activation of miR-124, a neurogenic microRNA with tumor suppressor activity, can induce the differentiation of retinoic acid-resistant neuroblastoma cells. Leveraging our established screen for miRNA modulatory small molecules, we validated PP121, a dual inhibitor of tyrosine and phosphoinositide kinases, as a robust inducer of miR-124. A combination of PP121 and miR-132-inducing bufalin synergistically arrests proliferation, induces differentiation, and prolongs the survival of differentiated MES SK-N-AS cells for 8 weeks. RNA- seq and deconvolution analyses revealed a collapse of the ADRN core regulatory circuitry (CRC) and the emergence of novel CRCs associated with chromaffin cells and Schwann cell precursors. Using a similar protocol, we differentiated and maintained other MES neuroblastoma, as well as glioblastoma cells, over 16 weeks. In conclusion, our novel protocol suggests a promising treatment for therapy-resistant cancers of the nervous system. Moreover, these long-lived, differentiated cells provide valuable models for studying mechanisms underlying differentiation, maturation, and senescence.

3.
Cell Rep ; 43(5): 114165, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38691450

ABSTRACT

The N6-methyladenosine (m6A) RNA modification is an important regulator of gene expression. m6A is deposited by a methyltransferase complex that includes methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14). High levels of METTL3/METTL14 drive the growth of many types of adult cancer, and METTL3/METTL14 inhibitors are emerging as new anticancer agents. However, little is known about the m6A epitranscriptome or the role of the METTL3/METTL14 complex in neuroblastoma, a common pediatric cancer. Here, we show that METTL3 knockdown or pharmacologic inhibition with the small molecule STM2457 leads to reduced neuroblastoma cell proliferation and increased differentiation. These changes in neuroblastoma phenotype are associated with decreased m6A deposition on transcripts involved in nervous system development and neuronal differentiation, with increased stability of target mRNAs. In preclinical studies, STM2457 treatment suppresses the growth of neuroblastoma tumors in vivo. Together, these results support the potential of METTL3/METTL14 complex inhibition as a therapeutic strategy against neuroblastoma.


Subject(s)
Cell Differentiation , Cell Proliferation , Methyltransferases , Neuroblastoma , Methyltransferases/metabolism , Methyltransferases/antagonists & inhibitors , Neuroblastoma/pathology , Neuroblastoma/metabolism , Neuroblastoma/drug therapy , Neuroblastoma/genetics , Humans , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cell Line, Tumor , Animals , Mice , Gene Expression Regulation, Neoplastic/drug effects , Adenosine/analogs & derivatives , Adenosine/metabolism , Adenosine/pharmacology
4.
Cell Rep ; 43(5): 114134, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38662542

ABSTRACT

Tumor MYCN amplification is seen in high-risk neuroblastoma, yet direct targeting of this oncogenic transcription factor has been challenging. Here, we take advantage of the dependence of MYCN-amplified neuroblastoma cells on increased protein synthesis to inhibit the activity of eukaryotic translation initiation factor 4A1 (eIF4A1) using an amidino-rocaglate, CMLD012824. Consistent with the role of this RNA helicase in resolving structural barriers in 5' untranslated regions (UTRs), CMLD012824 increased eIF4A1 affinity for polypurine-rich 5' UTRs, including that of the MYCN and associated transcripts with critical roles in cell proliferation. CMLD012824-mediated clamping of eIF4A1 spanned the full lengths of mRNAs, while translational inhibition was mediated through 5' UTR binding in a cap-dependent and -independent manner. Finally, CMLD012824 led to growth inhibition in MYCN-amplified neuroblastoma models without generalized toxicity. Our studies highlight the key role of eIF4A1 in MYCN-amplified neuroblastoma and demonstrate the therapeutic potential of disrupting its function.


Subject(s)
5' Untranslated Regions , Eukaryotic Initiation Factor-4A , N-Myc Proto-Oncogene Protein , Neuroblastoma , Animals , Humans , Mice , 5' Untranslated Regions/genetics , Cell Line, Tumor , Cell Proliferation , Eukaryotic Initiation Factor-4A/metabolism , Eukaryotic Initiation Factor-4A/genetics , N-Myc Proto-Oncogene Protein/metabolism , N-Myc Proto-Oncogene Protein/genetics , Neuroblastoma/genetics , Neuroblastoma/pathology , Neuroblastoma/metabolism , Neuroblastoma/drug therapy , RNA, Messenger/metabolism , RNA, Messenger/genetics , Female , Mice, Inbred C57BL
5.
Sci Adv ; 10(11): eadh9547, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38489372

ABSTRACT

Solid tumors, especially those with aberrant MYCN activation, often harbor an immunosuppressive microenvironment to fuel malignant growth and trigger treatment resistance. Despite this knowledge, there are no effective strategies to tackle this problem. We found that chemokine-like factor (CKLF) is highly expressed by various solid tumor cells and transcriptionally up-regulated by MYCN. Using the MYCN-driven high-risk neuroblastoma as a model system, we demonstrated that as early as the premalignant stage, tumor cells secrete CKLF to attract CCR4-expressing CD4+ cells, inducing immunosuppression and tumor aggression. Genetic depletion of CD4+ T regulatory cells abolishes the immunorestrictive and protumorigenic effects of CKLF. Our work supports that disrupting CKLF-mediated cross-talk between tumor and CD4+ suppressor cells represents a promising immunotherapeutic approach to battling MYCN-driven tumors.


Subject(s)
Chemokines , MARVEL Domain-Containing Proteins , N-Myc Proto-Oncogene Protein , Neuroblastoma , Humans , Cell Line, Tumor , Chemokines/metabolism , Gene Expression Regulation, Neoplastic , MARVEL Domain-Containing Proteins/metabolism , N-Myc Proto-Oncogene Protein/metabolism , Neuroblastoma/metabolism , Neuroblastoma/pathology , Neuroblastoma/therapy , Tumor Microenvironment
6.
Sci Rep ; 14(1): 3411, 2024 02 10.
Article in English | MEDLINE | ID: mdl-38341456

ABSTRACT

Cancer pain is the most feared symptom at end of life. Methadone has advantages over other opioids but is associated with significant variability in clinical response, making dosing challenging in practice. OPRM1 is the most studied pharmacogene associated with the pharmacodynamics of opioids, however reports on the association of the A118G polymorphism on opioid dose requirements are conflicting, with no reports including methadone as the primary intervention. This association study on OPRM1 A118G and response to methadone for pain management, includes a review of this genetic factor's role in inter-patient variability. Fifty-four adult patients with advanced cancer were recruited in a prospective, multi-centre, open label dose individualization study. Patient characteristics were not shown to influence methadone response, and no significant associations were observed for methadone dose or pain score. The findings of our review of association studies for OPRM1 A118G in advanced cancer pain demonstrate the importance of taking ancestry into account. While our sample size was small, our results were consistent with European populations, but in contrast to studies in Chinese patients, where carriers of the A118G polymorphism were associated with higher opioid dose requirements. Pharmacogenetic studies in palliative care are challenging, continued contribution will support future genotype-based drug dosing guidelines.


Subject(s)
Cancer Pain , Neoplasms , Adult , Humans , Analgesics, Opioid/therapeutic use , Cancer Pain/drug therapy , Cancer Pain/genetics , Genotype , Methadone/therapeutic use , Neoplasms/complications , Neoplasms/drug therapy , Neoplasms/genetics , Pain Management , Polymorphism, Single Nucleotide , Prospective Studies , Receptors, Opioid, mu/genetics
7.
J Immunother Cancer ; 10(12)2022 12.
Article in English | MEDLINE | ID: mdl-36521927

ABSTRACT

BACKGROUND: Immunotherapy in high-risk neuroblastoma (HR-NBL) does not live up to its full potential due to inadequate (adaptive) immune engagement caused by the extensive immunomodulatory capacity of HR-NBL. We aimed to tackle one of the most notable immunomodulatory processes in neuroblastoma (NBL), absence of major histocompatibility complex class I (MHC-I) surface expression, a process greatly limiting cytotoxic T cell engagement. We and others have previously shown that MHC-I expression can be induced by cytokine-driven immune modulation. Here, we aimed to identify tolerable pharmacological repurposing strategies to upregulate MHC-I expression and therewith enhance T cell immunogenicity in NBL. METHODS: Drug repurposing libraries were screened to identify compounds enhancing MHC-I surface expression in NBL cells using high-throughput flow cytometry analyses optimized for adherent cells. The effect of positive hits was confirmed in a panel of NBL cell lines and patient-derived organoids. Compound-treated NBL cell lines and organoids were cocultured with preferentially expressed antigen of melanoma (PRAME)-reactive tumor-specific T cells and healthy-donor natural killer (NK) cells to determine the in vitro effect on T cell and NK cell cytotoxicity. Additional immunomodulatory effects of histone deacetylase inhibitors (HDACi) were identified by transcriptome and translatome analysis of treated organoids. RESULTS: Drug library screening revealed MHC-I upregulation by inhibitor of apoptosis inhibitor (IAPi)- and HDACi drug classes. The effect of IAPi was limited due to repression of nuclear factor kappa B (NFκB) pathway activity in NBL, while the MHC-I-modulating effect of HDACi was widely translatable to a panel of NBL cell lines and patient-derived organoids. Pretreatment of NBL cells with the HDACi entinostat enhanced the cytotoxic capacity of tumor-specific T cells against NBL in vitro, which coincided with increased expression of additional players regulating T cell cytotoxicity (eg, TAP1/2 and immunoproteasome subunits). Moreover, MICA and MICB, important in NK cell cytotoxicity, were also increased by entinostat exposure. Intriguingly, this increase in immunogenicity was accompanied by a shift toward a more mesenchymal NBL cell lineage. CONCLUSIONS: This study indicates the potential of combining (immuno)therapy with HDACi to enhance both T cell-driven and NKcell-driven immune responses in patients with HR-NBL.


Subject(s)
Killer Cells, Natural , Neuroblastoma , Humans , Cell Lineage , Neuroblastoma/drug therapy , Neuroblastoma/genetics , Histocompatibility Antigens Class I , T-Lymphocytes, Cytotoxic , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use , Epigenesis, Genetic
8.
Sci Rep ; 12(1): 17422, 2022 10 19.
Article in English | MEDLINE | ID: mdl-36261449

ABSTRACT

Opioids are the therapeutic agents of choice to manage moderate to severe pain in patients with advanced cancer, however the unpredictable inter-individual response to opioid therapy remains a challenge for clinicians. While studies are few, the KCNJ6 gene is a promising target for investigating genetic factors that contribute to pain and analgesia response. This is the first association study on polymorphisms in KCNJ6 and response to methadone for pain management in advanced cancer. Fifty-four adult patients with advanced cancer were recruited across two study sites in a prospective, open label, dose individualisation study. Significant associations have been previously shown for rs2070995 and opioid response in opioid substitution therapy for heroin addiction and studies in chronic pain, with mixed results seen in postoperative pain. In this study, no associations were shown for rs2070995 and methadone dose or pain score, consistent with other studies conducted in patients receiving opioids for pain in advanced cancer. There are many challenges in conducting studies in advanced cancer with significant attrition and small sample sizes, however it is hoped that the results of our study will contribute to the evidence base and allow for continued development of gene-drug dosing guidelines for clinicians.


Subject(s)
Chronic Pain , Neoplasms , Adult , Humans , Methadone/therapeutic use , Analgesics, Opioid/therapeutic use , Pain Management , Prospective Studies , Chronic Pain/drug therapy , Neoplasms/complications , Neoplasms/drug therapy , Neoplasms/genetics , Death , G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics
9.
Micromachines (Basel) ; 13(9)2022 Aug 27.
Article in English | MEDLINE | ID: mdl-36144034

ABSTRACT

Highly durable and antimicrobial tantalum nitride/copper (TaN/Cu) nanocomposite coatings were deposited on D-9 stainless steel substrates by pulsed magnetron sputtering. The Cu content in the coating was varied in the range of 1.42-35.42 atomic % (at.%). The coatings were characterized by electron probe microanalyzer, X-ray diffraction, scanning electron microscope and atomic force microscope. The antibacterial properties of the TaN/Cu coatings against gram-negative Pseudomonas aeruginosa were evaluated using a cell culture test. The peak hardness and Young's modulus of TaN/Cu with 10.46 at.% Cu were 24 and 295 GPa, respectively, which amounted to 15 and 41.67% higher than Cu-free TaN. Among all, TaN/Cu with 10.46 at.% exhibited the lowest friction coefficient. The TaN/Cu coatings exhibited significantly higher antibacterial activity than Cu-free TaN against Pseudomonas aeruginosa. On TaN, the bacterial count was about 4 × 106 CFU, whereas it was dropped to 1.2 × 102 CFU in case of TaN/Cu with 10.46 at.% Cu. The bacterial count was decreased from 9 to 6 when the Cu content increased from 25.54 to 30.04 at.%. Live bacterial cells were observed in the SEM images of TaN, and dead cells were found on TaN/Cu. Overall, TaN/Cu with 10.46 at.% Cu was found to be a potential coating composition in terms of higher antimicrobial activity and mechanical durability.

10.
Nat Cancer ; 3(10): 1228-1246, 2022 10.
Article in English | MEDLINE | ID: mdl-36138189

ABSTRACT

Apart from the anti-GD2 antibody, immunotherapy for neuroblastoma has had limited success due to immune evasion mechanisms, coupled with an incomplete understanding of predictors of response. Here, from bulk and single-cell transcriptomic analyses, we identify a subset of neuroblastomas enriched for transcripts associated with immune activation and inhibition and show that these are predominantly characterized by gene expression signatures of the mesenchymal lineage state. By contrast, tumors expressing adrenergic lineage signatures are less immunogenic. The inherent presence or induction of the mesenchymal state through transcriptional reprogramming or therapy resistance is accompanied by innate and adaptive immune gene activation through epigenetic remodeling. Mesenchymal lineage cells promote T cell infiltration by secreting inflammatory cytokines, are efficiently targeted by cytotoxic T and natural killer cells and respond to immune checkpoint blockade. Together, we demonstrate that distinct immunogenic phenotypes define the divergent lineage states of neuroblastoma and highlight the immunogenic potential of the mesenchymal lineage.


Subject(s)
Adrenergic Agents , Neuroblastoma , Humans , Cell Lineage/genetics , Immune Checkpoint Inhibitors , Neuroblastoma/genetics , Cytokines/genetics , Phenotype
11.
Pharmacogenomics ; 23(5): 281-289, 2022 04.
Article in English | MEDLINE | ID: mdl-35189719

ABSTRACT

Background: The prescription of methadone in advanced cancer poses multiple challenges due to the considerable interpatient variation seen in effective dose and toxicity. Previous reports have suggested that ARRB2 influences the response to methadone in opioid substitution therapy. Associations with opioid response for pain management in advanced cancer are conflicting, with no studies including methadone as the primary intervention. Methods: In a prospective, multicenter, open-label dose-individualization study, we investigated whether polymorphisms in ARRB2 were associated with methadone dose requirements and pain severity. Results: Significant associations were found for rs3786047, rs1045280, rs2036657 and pain score. Conclusion: While studies are few and the sample size small, ARRB2 genotyping may assist in individualized management of the most feared symptom in advanced cancer.


Subject(s)
Cancer Pain , Neoplasms , Analgesics, Opioid/adverse effects , Cancer Pain/drug therapy , Cancer Pain/genetics , Humans , Methadone/therapeutic use , Neoplasms/drug therapy , Neoplasms/genetics , Pain/drug therapy , Pain/genetics , Polymorphism, Single Nucleotide/genetics , Prospective Studies , beta-Arrestin 2/genetics
12.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 2758-2763, 2022 Oct.
Article in English | MEDLINE | ID: mdl-33020733

ABSTRACT

Corona virus disease (COVID 19) is an infectious respiratory disease caused by the novel virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With many countries implementing lockdown the surgical activities in the division of otolaryngology across the world has been affected with many hospital confining themselves to only emergency or essential surgeries. The aim of this work is to report and discuss the in the surgical activity of the otolaryngology unit of the St John's National Academy of Health Sciences, Bangalore (India) during the pandemic. We performed acute and subacute emergencies which include diagnosis and treatment of malignant tumors of the head and neck, management of airway emergencies in adults and children, drainage of abscesses of the head and neck, Foreign body removal, emergency nasal debridement and surgeries for the unsafe ear. With the pandemic the surgical activities in otolaryngology changed drastically and with strict protocol and triaging put in place the risk for Health care workers was avoided and services to patients delivered.

13.
Cell Rep ; 36(2): 109363, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34260934

ABSTRACT

Although activating mutations of the anaplastic lymphoma kinase (ALK) membrane receptor occur in ∼10% of neuroblastoma (NB) tumors, the role of the wild-type (WT) receptor, which is aberrantly expressed in most non-mutated cases, is unclear. Both WT and mutant proteins undergo extracellular domain (ECD) cleavage. Here, we map the cleavage site to Asn654-Leu655 and demonstrate that cleavage inhibition of WT ALK significantly impedes NB cell migration with subsequent prolongation of survival in mouse models. Cleavage inhibition results in the downregulation of an epithelial-to-mesenchymal transition (EMT) gene signature, with decreased nuclear localization and occupancy of ß-catenin at EMT gene promoters. We further show that cleavage is mediated by matrix metalloproteinase 9, whose genetic and pharmacologic inactivation inhibits cleavage and decreases NB cell migration. Together, our results indicate a pivotal role for WT ALK ECD cleavage in NB pathogenesis, which may be harnessed for therapeutic benefit.


Subject(s)
Anaplastic Lymphoma Kinase/chemistry , Anaplastic Lymphoma Kinase/metabolism , Cell Movement , Neuroblastoma/pathology , Amino Acid Sequence , Anaplastic Lymphoma Kinase/antagonists & inhibitors , Anaplastic Lymphoma Kinase/genetics , Animals , Base Sequence , Cell Line, Tumor , Cell Membrane/metabolism , Disease Models, Animal , Epithelial-Mesenchymal Transition/genetics , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glycine/chemistry , HEK293 Cells , Humans , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Inbred C57BL , Mutation/genetics , NIH 3T3 Cells , Neoplasm Invasiveness , Neuroblastoma/genetics , Protein Binding , Protein Domains
14.
Genome Biol ; 22(1): 78, 2021 03 08.
Article in English | MEDLINE | ID: mdl-33685491

ABSTRACT

Spatial transcriptomic and proteomic technologies have provided new opportunities to investigate cells in their native microenvironment. Here we present Giotto, a comprehensive and open-source toolbox for spatial data analysis and visualization. The analysis module provides end-to-end analysis by implementing a wide range of algorithms for characterizing tissue composition, spatial expression patterns, and cellular interactions. Furthermore, single-cell RNAseq data can be integrated for spatial cell-type enrichment analysis. The visualization module allows users to interactively visualize analysis outputs and imaging features. To demonstrate its general applicability, we apply Giotto to a wide range of datasets encompassing diverse technologies and platforms.


Subject(s)
Computational Biology/methods , Gene Expression Profiling/methods , In Situ Hybridization , Software , Data Analysis , Image Processing, Computer-Assisted , Immunohistochemistry/methods , In Situ Hybridization/methods , Organ Specificity/genetics , Spatial Analysis , Transcriptome
15.
Front Oncol ; 11: 773186, 2021.
Article in English | MEDLINE | ID: mdl-35198433

ABSTRACT

PURPOSE: Cyclin-dependent kinases (CDKs) that have critical roles in RNA polymerase II (Pol II)-mediated gene transcription are emerging as therapeutic targets in cancer. We have previously shown that THZ1, a covalent inhibitor of CDKs 7/12/13, leads to cytotoxicity in MYCN-amplified neuroblastoma through the downregulation of super-enhancer-associated transcriptional upregulation. Here we determined the effects of YKL-5-124, a novel covalent inhibitor with greater selectivity for CDK7 in neuroblastoma cells. EXPERIMENTAL DESIGN: We tested YKL-5-124 in MYCN-amplified and nonamplified neuroblastoma cells individually and in combination with other inhibitors in cell line and animal models. Cell viability, target validation, effects on cell cycle and transcription were analyzed. RESULTS: CDK7 inhibition with YKL-5-124 did not lead to significant cell death, but resulted in aberrant cell cycle progression especially in MYCN-amplified cells. Unlike THZ1, YKL-5-124 had minimal effects on Pol II C-terminal domain phosphorylation, but significantly inhibited that of the CDK1 and CDK2 cell cycle kinases. Combining YKL-5-124 with the BRD4 inhibitor JQ1 resulted in synergistic cytotoxicity. A distinct MYCN-gene expression signature associated with resistance to BRD4 inhibition was suppressed with the combination. The synergy between YKL-5-124 and JQ1 translated into significant tumor regression in cell line and patient-derived xenograft mouse models of neuroblastoma. CONCLUSIONS: The combination of CDK7 and BRD4 inhibition provides a therapeutic option for neuroblastoma and suggests that the addition of YKL-5-124 could improve the therapeutic efficacy of JQ1 and delay resistance to BRD4 inhibition.

16.
Spectrochim Acta A Mol Biomol Spectrosc ; 248: 119187, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33234481

ABSTRACT

This study aims to explore the spectroscopic properties of a Sr1.0Ba2.0B6O12:0.5Sm3+ phosphor synthesized using the solid-state reaction method. The morphology and elemental composition of the phosphor were determined using scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. Phase changes and crystallite phases in the phosphor were studied using differential-scanning calorimetry and X-ray diffraction, respectively. Raman and Fourier-transform infrared spectra were used to identify the molecular vibrations in the phosphor. The energy bandgap and bonding nature of the phosphor were analyzed using the absorption spectrum. The nephelauxetic ratios determined from the absorption peaks revealed the presence of both ionic and covalent bonding in the phosphor. Judd-Ofelt parameters, along with radiative properties of the phosphor, were evaluated using the peaks in the absorption spectrum. Colorimetric analysis using the photoluminescence spectrum showed that the Sr1.0Ba2.0B6O12:0.5Sm3+ phosphor emits a cool-white light. The higher values of the spectroscopic quality factor, stimulated-emission cross-section, quantum efficiency, and the white-light emission of the phosphor suggest that Sr1.0Ba2.0B6O12:0.5Sm3+ is useful for display and lighting applications.

17.
Environ Sci Pollut Res Int ; 28(6): 7404-7422, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33033928

ABSTRACT

We demonstrate enhanced anti-corrosion and anti-biofouling properties of graphene oxide-silica-polydimethylsiloxane (GSP) coating on carbon steel (CS). Electrochemical analyses of GSP-coated carbon steel exposed to Gram-positive Bacillus sp., Gram-negative Pseudomonas sp., and freshwater bacterial cultures for 72 h showed a 3-5 orders of magnitude reduction in icorr values and high impedance values (107 Ω) as compared with polished specimens. The corrosion protection efficiency of GSP-coated specimens was 99.9% against Bacillus sp. and freshwater culture and it was 89.6% against Pseudomonas sp. Evaluation of anti-biofouling property of GSP coating using microbiological and epifluorescence microscopic techniques showed three order reductions in total viable cells on GSP-coated specimens exposed to bacterial cultures. Confocal laser scanning microscopic analysis of biofilm architecture confirmed a significant reduction of biomass and biofilm thickness on GSP-coated CS demonstrating an excellent anti-biofouling activity of GSP.


Subject(s)
Biofouling , Nanocomposites , Biofilms , Biofouling/prevention & control , Corrosion , Dimethylpolysiloxanes , Graphite
18.
Eur J Cancer ; 136: 52-68, 2020 09.
Article in English | MEDLINE | ID: mdl-32653773

ABSTRACT

Only one class of targeted agents (anti-GD2 antibodies) has been incorporated into front-line therapy for neuroblastoma since the 1980s. The Neuroblastoma New Drug Development Strategy (NDDS) initiative commenced in 2012 to accelerate the development of new drugs for neuroblastoma. Advances have occurred, with eight of nine high-priority targets being evaluated in paediatric trials including anaplastic lymphoma kinase inhibitors being investigated in front-line, but significant challenges remain. This article reports the conclusions of the second NDDS forum, which expanded across the Atlantic to further develop the initiative. Pre-clinical and clinical data for 40 genetic targets and mechanisms of action were prioritised and drugs were identified for early-phase trials. Strategies to develop drugs targeting TERT, telomere maintenance, ATRX, alternative lengthening of telomeres (ALT), BRIP1 and RRM2 as well as direct targeting of MYCN are high priority and should be championed for drug discovery. Promising pre-clinical data suggest that targeting of ALT by ATM or PARP inhibition may be potential strategies. Drugs targeting CDK2/9, CDK7, ATR and telomere maintenance should enter paediatric clinical development rapidly. Optimising the response to anti-GD2 by combinations with chemotherapy, targeted agents and other immunological targets are crucial. Delivering this strategy in the face of small patient cohorts, genomically defined subpopulations and a large number of permutations of combination trials, demands even greater international collaboration. In conclusion, the NDDS provides an internationally agreed, biologically driven selection of prioritised genetic targets and drugs. Improvements in the strategy for conducting trials in neuroblastoma will accelerate bringing these new drugs more rapidly to front-line therapy.


Subject(s)
Brain Neoplasms/drug therapy , Drug Development , Neuroblastoma/drug therapy , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/therapeutic use , Brain Neoplasms/pathology , Child , Congresses as Topic , Drug Development/methods , Drug Development/organization & administration , Drug Development/trends , Drug Discovery/methods , Drug Discovery/organization & administration , Drug Discovery/trends , Europe , Humans , Medical Oncology/methods , Medical Oncology/organization & administration , Medical Oncology/trends , Molecular Targeted Therapy/methods , Molecular Targeted Therapy/trends , Neuroblastoma/pathology , Pediatrics/methods , Pediatrics/organization & administration , Pediatrics/trends , Protein Kinase Inhibitors/isolation & purification , Protein Kinase Inhibitors/therapeutic use , Therapies, Investigational/methods , Therapies, Investigational/trends
19.
Cell Stem Cell ; 26(4): 579-592.e6, 2020 04 02.
Article in English | MEDLINE | ID: mdl-32142683

ABSTRACT

Neuroblastoma (NB), derived from the neural crest (NC), is the most common pediatric extracranial solid tumor. Here, we establish a platform that allows the study of human NBs in mouse-human NC chimeras. Chimeric mice were produced by injecting human NC cells carrying NB relevant oncogenes in utero into gastrulating mouse embryos. The mice developed tumors composed of a heterogenous cell population that resembled that seen in primary NBs of patients but were significantly different from homogeneous tumors formed in xenotransplantation models. The human tumors emerged in immunocompetent hosts and were extensively infiltrated by mouse cytotoxic T cells, reflecting a vigorous host anti-tumor immune response. However, the tumors blunted the immune response by inducing infiltration of regulatory T cells and expression of immune-suppressive molecules similar to escape mechanisms seen in human cancer patients. Thus, this experimental platform allows the study of human tumor initiation, progression, manifestation, and tumor-immune-system interactions in an animal model system.


Subject(s)
Neural Crest , Neuroblastoma , Animals , Child , Chimera , Disease Models, Animal , Humans , Mice
20.
Nat Commun ; 11(1): 913, 2020 02 14.
Article in English | MEDLINE | ID: mdl-32060267

ABSTRACT

Aggressive cancers often have activating mutations in growth-controlling oncogenes and inactivating mutations in tumor-suppressor genes. In neuroblastoma, amplification of the MYCN oncogene and inactivation of the ATRX tumor-suppressor gene correlate with high-risk disease and poor prognosis. Here we show that ATRX mutations and MYCN amplification are mutually exclusive across all ages and stages in neuroblastoma. Using human cell lines and mouse models, we found that elevated MYCN expression and ATRX mutations are incompatible. Elevated MYCN levels promote metabolic reprogramming, mitochondrial dysfunction, reactive-oxygen species generation, and DNA-replicative stress. The combination of replicative stress caused by defects in the ATRX-histone chaperone complex, and that induced by MYCN-mediated metabolic reprogramming, leads to synthetic lethality. Therefore, ATRX and MYCN represent an unusual example, where inactivation of a tumor-suppressor gene and activation of an oncogene are incompatible. This synthetic lethality may eventually be exploited to improve outcomes for patients with high-risk neuroblastoma.


Subject(s)
N-Myc Proto-Oncogene Protein/genetics , Neuroblastoma/metabolism , X-linked Nuclear Protein/genetics , Animals , Child, Preschool , Cohort Studies , Female , Gene Amplification , Humans , Infant , Male , Mice , Mitochondria/genetics , Mitochondria/metabolism , Mutation , N-Myc Proto-Oncogene Protein/metabolism , Neuroblastoma/genetics , Reactive Oxygen Species/metabolism , X-linked Nuclear Protein/metabolism
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