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1.
Sci Rep ; 14(1): 3357, 2024 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336906

RESUMO

Mutations in the KCNT1 potassium channel cause severe forms of epilepsy which are poorly controlled with current treatments. In vitro studies have shown that KCNT1-epilepsy mutations are gain of function, significantly increasing K+ current amplitudes. To investigate if Drosophila can be used to model human KCNT1 epilepsy, we generated Drosophila melanogaster lines carrying human KCNT1 with the patient mutation G288S, R398Q or R928C. Expression of each mutant channel in GABAergic neurons gave a seizure phenotype which responded either positively or negatively to 5 frontline epilepsy drugs most commonly administered to patients with KCNT1-epilepsy, often with little or no improvement of seizures. Cannabidiol showed the greatest reduction of the seizure phenotype while some drugs increased the seizure phenotype. Our study shows that Drosophila has the potential to model human KCNT1- epilepsy and can be used as a tool to assess new treatments for KCNT1- epilepsy.


Assuntos
Drosophila , Epilepsia , Canais de Potássio Ativados por Sódio , Animais , Humanos , Drosophila/genética , Drosophila melanogaster/genética , Avaliação Pré-Clínica de Medicamentos , Epilepsia/tratamento farmacológico , Epilepsia/genética , Modelos Animais , Mutação , Proteínas do Tecido Nervoso/genética , Canais de Potássio Ativados por Sódio/genética , Convulsões/tratamento farmacológico , Convulsões/genética , Transgenes
2.
PLoS One ; 18(7): e0287905, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37498862

RESUMO

Dengue Virus (DENV) is a serious threat to human life worldwide and is one of the most dangerous vector-borne diseases, causing thousands of deaths annually. We constructed a comprehensive PPI map of DENV with its host Homo sapiens and performed various bioinformatics analyses. We found 1195 interactions between 858 human and 10 DENV proteins. Pathway enrichment analysis was performed on the two sets of gene products, and the top 5 human proteins with the maximum number of interactions with dengue viral proteins revealed noticeable results. The non-structural protein NS1 in DENV had the maximum number of interactions with the host protein, followed by NS5 and NS3. Among the human proteins, HBA1 and UBE2I were associated with 7 viral proteins, and 3 human proteins (CSNK2A1, RRP12, and HSP90AB1) were found to interact with 6 viral proteins. Pharmacophore-based virtual screening of millions of compounds in the public databases was performed to identify potential DENV-NS1 inhibitors. The lead compounds were selected based on RMSD values, docking scores, and strong binding affinities. The top ten hit compounds were subjected to ADME profiling which identified compounds C2 (MolPort-044-180-163) and C6 (MolPort-001-742-737) as lead inhibitors against DENV-NS1. Molecular dynamics trajectory analysis and intermolecular interactions between NS1 and the ligands displayed the molecular stability of the complexes in the cellular environment. The in-silico approaches used in this study could pave the way for the development of potential specie-specific drugs and help in eliminating deadly viral infections. Therefore, experimental and clinical assays are required to validate the results of this study.


Assuntos
Vírus da Dengue , Dengue , Humanos , Vírus da Dengue/genética , Mapas de Interação de Proteínas , Simulação de Dinâmica Molecular , Proteínas Virais/metabolismo , Proteínas não Estruturais Virais/genética , Dengue/tratamento farmacológico
3.
Heliyon ; 9(5): e16177, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37251908

RESUMO

This research has analyzed the role of learning in an organization while measuring and managing sustainable organizational performance. Furthermore, our research has also included the intervening role of organizational networking and organizational innovation while analyzing the relationship between organizational learning and sustainable organizational performance. Our research has adopted a quantitative approach while using the survey method to collect data from 710 owners of the manufacturing sector belonging to the Small and Medium Enterprises SMEs operating in Laos. Informed consent was obtained from all participants for your research. Structure equation modeling SEM was used through partial least square PLS software to test the collected data's reliability and validity and test the hypothesis to meet the research objectives. The study's findings reveal that organizational learning is vital to organizational performance and success. Information sources (networks) moderate the relationship between innovation and organizational performance. Our findings confirm that innovation is disruptive if it is not well-informed and well-processed. The research concludes that organizational learning is very vital for sustainable organizational performance. The current research contributes to the body of knowledge by examining sustainable organizational performance from an entirely different perspective.

4.
Metabolites ; 13(5)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37233683

RESUMO

Aneuploidy, or having a disrupted genome, is an aberration commonly found in tumours but rare in normal tissues. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift, which makes these cells sensitive to internal and environmental stresses. Using Drosophila as a model, we investigated the changes in transcription in response to ongoing changes to ploidy (chromosomal instability, CIN). We noticed changes in genes affecting one-carbon metabolism, specifically those affecting the production and use of s-adenosyl methionine (SAM). The depletion of several of these genes has led to cell death by apoptosis in CIN cells but not in normal proliferating cells. We found that CIN cells are particularly sensitive to SAM metabolism at least partly because of its role in generating polyamines. Feeding animals spermine was seen to rescue the cell death caused by the loss of SAM synthase in CIN tissues. The loss of polyamines led to decreased rates of autophagy and sensitivity to reactive oxygen species (ROS), which we have shown to contribute significantly to cell death in CIN cells. These findings suggest that a well-tolerated metabolic intervention such as polyamine inhibition has the potential to target CIN tumours via a relatively well-characterised mechanism.

5.
Acta Paediatr ; 112(2): 273-276, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36271909

RESUMO

Sudden infant death syndrome (SIDS) occurs more often in male than in female infants, suggesting involvement of the X-chromosome. Histopathological studies have suggested that altered expression of the Neurokinin-1 receptor may also play a role in the pathogenesis of SIDS. It was hypothesised that genetic variants in three X-chromosome-encoded microRNA (miRNA/miR), known to down-regulate expression of the Neurokinin-1 receptor, may contribute to SIDS. AIM: To identify sequence variants in the miRNAs within a study cohort (27 cases of SIDS and 28 controls) and determine if there was a difference in the frequencies in male and female SIDS infants. METHODS: Genomic DNA prepared from stored blood spots was amplified and sequenced to identify genetic variants in miR500A, miR500B and miR320D2. RESULTS: No novel variants in the miRNAs were identified in our study cohort. We identified one known single-nucleotide polymorphism (SNP) in miR320D2: rs5907732 G/T, in both cases and controls. No significant difference in the SNP frequency was observed between male and female SIDS cases. CONCLUSION: This pilot study suggests that sequence variants in three miRNAs do not contribute to the reported higher prevalence of SIDS in male infants and do not contribute to the pathogenesis of SIDS in our cohort.


Assuntos
MicroRNAs , Morte Súbita do Lactente , Lactente , Humanos , Masculino , Feminino , Receptores da Neurocinina-1/genética , Morte Súbita do Lactente/genética , Morte Súbita do Lactente/epidemiologia , MicroRNAs/genética , Projetos Piloto , Polimorfismo de Nucleotídeo Único
6.
Biomolecules ; 12(12)2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36551330

RESUMO

Cancer metabolic reprogramming is essential for maintaining cancer cell survival and rapid replication. A common target of this metabolic reprogramming is one-carbon metabolism which is notable for its function in DNA synthesis, protein and DNA methylation, and antioxidant production. Polyamines are a key output of one-carbon metabolism with widespread effects on gene expression and signaling. As a result of these functions, one-carbon and polyamine metabolism have recently drawn a lot of interest for their part in cancer malignancy. Therapeutic inhibitors that target one-carbon and polyamine metabolism have thus been trialed as anticancer medications. The significance and future possibilities of one-carbon and polyamine metabolism as a target in cancer therapy are discussed in this review.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Carbono/metabolismo , Poliaminas/metabolismo , Metilação de DNA , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo
7.
Int J Mol Sci ; 23(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36499459

RESUMO

KCNT1 (K+ channel subfamily T member 1) is a sodium-activated potassium channel highly expressed in the nervous system which regulates neuronal excitability by contributing to the resting membrane potential and hyperpolarisation following a train of action potentials. Gain of function mutations in the KCNT1 gene are the cause of neurological disorders associated with different forms of epilepsy. To gain insights into the underlying pathobiology we investigated the functional effects of 9 recently published KCNT1 mutations, 4 previously studied KCNT1 mutations, and one previously unpublished KCNT1 variant of unknown significance. We analysed the properties of KCNT1 potassium currents and attempted to find a correlation between the changes in KCNT1 characteristics due to the mutations and severity of the neurological disorder they cause. KCNT1 mutations identified in patients with epilepsy were introduced into the full length human KCNT1 cDNA using quick-change site-directed mutagenesis protocol. Electrophysiological properties of different KCNT1 constructs were investigated using a heterologous expression system (HEK293T cells) and patch clamping. All mutations studied, except T314A, increased the amplitude of KCNT1 currents, and some mutations shifted the voltage dependence of KCNT1 open probability, increasing the proportion of channels open at the resting membrane potential. The T314A mutation did not affect KCNT1 current amplitude but abolished its voltage dependence. We observed a positive correlation between the severity of the neurological disorder and the KCNT1 channel open probability at resting membrane potential. This suggests that gain of function KCNT1 mutations cause epilepsy by increasing resting potassium conductance and suppressing the activity of inhibitory neurons. A reduction in action potential firing in inhibitory neurons due to excessively high resting potassium conductance leads to disinhibition of neural circuits, hyperexcitability and seizures.


Assuntos
Epilepsia , Proteínas do Tecido Nervoso , Humanos , Canais de Potássio Ativados por Sódio/genética , Células HEK293 , Proteínas do Tecido Nervoso/metabolismo , Epilepsia/genética , Mutação , Potássio/metabolismo
8.
BMC Bioinformatics ; 23(1): 251, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35751030

RESUMO

Glioma is the most aggressive and dangerous primary brain tumor with a survival time of less than 14 months. Segmentation of tumors is a necessary task in the image processing of the gliomas and is important for its timely diagnosis and starting a treatment. Using 3D U-net architecture to perform semantic segmentation on brain tumor dataset is at the core of deep learning. In this paper, we present a unique cloud-based 3D U-Net method to perform brain tumor segmentation using BRATS dataset. The system was effectively trained by using Adam optimization solver by utilizing multiple hyper parameters. We got an average dice score of 95% which makes our method the first cloud-based method to achieve maximum accuracy. The dice score is calculated by using Sørensen-Dice similarity coefficient. We also performed an extensive literature review of the brain tumor segmentation methods implemented in the last five years to get a state-of-the-art picture of well-known methodologies with a higher dice score. In comparison to the already implemented architectures, our method ranks on top in terms of accuracy in using a cloud-based 3D U-Net framework for glioma segmentation.


Assuntos
Neoplasias Encefálicas , Aprendizado Profundo , Glioma , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Computação em Nuvem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Semântica
9.
World J Virol ; 10(6): 288-300, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34909403

RESUMO

Almost all the cellular processes in a living system are controlled by proteins: They regulate gene expression, catalyze chemical reactions, transport small molecules across membranes, and transmit signal across membranes. Even, a viral infection is often initiated through virus-host protein interactions. Protein-protein interactions (PPIs) are the physical contacts between two or more proteins and they represent complex biological functions. Nowadays, PPIs have been used to construct PPI networks to study complex pathways for revealing the functions of unknown proteins. Scientists have used PPIs to find the molecular basis of certain diseases and also some potential drug targets. In this review, we will discuss how PPI networks are essential to understand the molecular basis of virus-host relationships and several databases which are dedicated to virus-host interaction studies. Here, we present a short but comprehensive review on PPIs, including the experimental and computational methods of finding PPIs, the databases dedicated to virus-host PPIs, and the associated various applications in protein interaction networks of some lethal viruses with their hosts.

10.
Trials ; 22(1): 618, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526081

RESUMO

OBJECTIVES: Considering the therapeutic potential of honey and Nigella sativa (HNS) in coronavirus disease 2019 (COVID-19) patients, the objective of the study is defined to evaluate the prophylactic role of HNS. TRIAL DESIGN: The study is a randomized, placebo-controlled, adaptive clinical trial with parallel group design, superiority framework with an allocation ratio of 1:1 among experimental (HNS) and placebo group. An interim analysis will be done when half of the patients have been recruited to evaluate the need to adapt sample size, efficacy, and futility of the trial. PARTICIPANTS: All asymptomatic patients with hospital or community based COVID-19 exposure will be screened if they have had 4 days exposure to a confirmed case. Non-pregnant adults with significant exposure level will be enrolled in the study High-risk exposure (<6 feet distance for >10min without face protection) Moderate exposure (<6 feet distance for >10min with face protection) Subjects with acute or chronic infection, COVID-19 vaccinated, and allergy to HNS will be excluded from the study. Recruitment will be done at Shaikh Zayed Post-Graduate Medical Institute, Ali Clinic and Doctors Lounge in Lahore (Pakistan). INTERVENTION AND COMPARATOR: In this clinical study, patients will receive either raw natural honey (0.5 g) and encapsulated organic Nigella sativa seeds (40 mg) per kg body weight per day or empty capsule with and 30 ml of 5% dextrose water as a placebo for 14 days. Both the natural products will be certified for standardization by Government College University (Botany department). Furthermore, each patient will be given standard care therapy according to version 3.0 of the COVID-19 clinical management guidelines by the Ministry of National Health Services of Pakistan. MAIN OUTCOMES: Primary outcome will be Incidence of COVID-19 cases within 14 days of randomisation. Secondary endpoints include incidence of COVID-19-related symptoms, hospitalizations, and deaths along with the severity of COVID-19-related symptoms till 14th day of randomization. RANDOMISATION: Participants will be randomized into experimental and control groups (1:1 allocation ratio) via the lottery method. There will be stratification based on high risk and moderate risk exposure. BLINDING (MASKING): Quadruple blinding will be ensured for the participants, care providers and outcome accessors. Data analysts will also be blinded to avoid conflict of interest. Site principal investigator will be responsible for ensuring masking. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): 1000 participants will be enrolled in the study with 1:1 allocation. TRIAL STATUS: The final protocol version 1.4 was approved by institutional review board of Shaikh Zayed Post-Graduate Medical Complex on February 15, 2021. The trial recruitment was started on March 05, 2021, with a trial completion date of February 15, 2022. TRIAL REGISTRATION: Clinical trial was registered on February 23, 2021, www.clinicaltrials.gov with registration ID NCT04767087 . FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). With the intention of expediting dissemination of this trial, the conventional formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines.


Assuntos
COVID-19 , Mel , Nigella sativa , Adulto , Hospitais , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , SARS-CoV-2 , Resultado do Tratamento
11.
BMC Infect Dis ; 20(1): 480, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32631335

RESUMO

BACKGROUND: Influenza A virus (IAV) infection is a serious public health problem not only in South East Asia but also in European and African countries. Scientists are using network biology to dig deep into the essential host factors responsible for regulation of virus infections. Researchers can explore the virus invasion into the host cells by studying the virus-host relationship based on their protein-protein interaction network. METHODS: In this study, we present a comprehensive IAV-host protein-protein interaction network that is obtained based on the literature-curated protein interaction datasets and some important interaction databases. The network is constructed in Cytoscape and analyzed with its plugins including CytoHubba, CytoCluster, MCODE, ClusterViz and ClusterOne. In addition, Gene Ontology and KEGG enrichment analyses are performed on the highly IAV-associated human proteins. We also compare the current results with those from our previous study on Hepatitis C Virus (HCV)-host protein-protein interaction network in order to find out valuable information. RESULTS: We found out 1027 interactions among 829 proteins of which 14 are viral proteins and 815 belong to human proteins. The viral protein NS1 has the highest number of associations with human proteins followed by NP, PB2 and so on. Among human proteins, LNX2, MEOX2, TFCP2, PRKRA and DVL2 have the most interactions with viral proteins. Based on KEGG pathway enrichment analysis of the highly IAV-associated human proteins, we found out that they are enriched in the KEGG pathway of basal cell carcinoma. Similarly, the result of KEGG analysis of the common host factors involved in IAV and HCV infections shows that these factors are enriched in the infection pathways of Hepatitis B Virus (HBV), Viral Carcinoma, measles and certain other viruses. CONCLUSION: It is concluded that the list of proteins we identified might be used as potential drug targets for the drug design against the infectious diseases caused by Influenza A Virus and other viruses.


Assuntos
Interações Hospedeiro-Patógeno/genética , Vírus da Influenza A/metabolismo , Influenza Humana/metabolismo , Mapas de Interação de Proteínas/genética , Biologia de Sistemas/métodos , Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Hepacivirus/metabolismo , Hepatite C/metabolismo , Hepatite C/virologia , Humanos , Influenza Humana/virologia , Proteínas do Nucleocapsídeo , Fatores de Transcrição/genética , Proteínas do Core Viral/genética , Proteínas não Estruturais Virais/genética , Replicação Viral
12.
Sci Rep ; 10(1): 8719, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32457456

RESUMO

Human papilloma virus (HPV) is a serious threat to human life globally with over 100 genotypes including cancer causing high risk HPVs. Study on protein interaction maps of pathogens with their host is a recent trend in 'omics' era and has been practiced by researchers to find novel drug targets. In current study, we construct an integrated protein interaction map of HPV with its host human in Cytoscape and analyze it further by using various bioinformatics tools. We found out 2988 interactions between 12 HPV and 2061 human proteins among which we identified MYLK, CDK7, CDK1, CDK2, JAK1 and 6 other human proteins associated with multiple viral oncoproteins. The functional enrichment analysis of these top-notch key genes is performed using KEGG pathway and Gene Ontology analysis, which reveals that the gene set is enriched in cell cycle a crucial cellular process, and the second most important pathway in which the gene set is involved is viral carcinogenesis. Among the viral proteins, E7 has the highest number of associations in the network followed by E6, E2 and E5. We found out a group of genes which is not targeted by the existing drugs available for HPV infections. It can be concluded that the molecules found in this study could be potential targets and could be used by scientists in their drug design studies.


Assuntos
Redes Reguladoras de Genes , Papillomaviridae/fisiologia , Infecções por Papillomavirus/metabolismo , Proteínas Virais/metabolismo , Análise por Conglomerados , Biologia Computacional/métodos , Interações Hospedeiro-Patógeno , Humanos , Anotação de Sequência Molecular , Papillomaviridae/metabolismo , Infecções por Papillomavirus/virologia , Mapas de Interação de Proteínas , Proteômica
13.
Biol Open ; 7(10)2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30327366

RESUMO

Aneuploidy -- having an unbalanced genome - is poorly tolerated at the cellular and organismal level. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift which makes these cells sensitive to internal and environmental stresses. Using Drosophila as a model, we found that protein folding stress is exacerbated by redox stress that occurs in response to ongoing changes to ploidy (chromosomal instability, CIN). We also found that if de novo nucleotide synthesis is blocked, CIN cells are dependent on a high level of lysosome function to survive. Depletion of adenosine monophosphate (AMP) synthesis enzymes led to DNA damage in CIN cells, which showed elevated activity of the DNA repair enzyme activated poly(ADP ribose) polymerase (PARP). PARP activation causes depletion of its substrate, nicotinamide adenine dinucleotide (NAD+) and subsequent loss of Adenosine Tri-Phosphate (ATP), and we found that adding ATP or nicotinamide (a precursor in the synthesis of NAD+) could rescue the observed phenotypes. These findings provide ways to interpret, target and exploit aneuploidy, which has the potential to offer tumour-specific therapies.

14.
Sci Rep ; 7(1): 11531, 2017 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-28912546

RESUMO

Tumors frequently fail to pass on all their chromosomes correctly during cell division, and this chromosomal instability (CIN) causes irregular aneuploidy and oxidative stress in cancer cells. Our objective was to test knockdowns of metabolic enzymes in Drosophila to find interventions that could exploit the differences between normal and CIN cells to block CIN tumor growth without harming the host animal. We found that depleting by RNAi or feeding the host inhibitors against phosphoenolpyruvate carboxykinase (PEPCK) was able to block the growth of CIN tissue in a brat tumor explant model. Increasing NAD+ or oxidising cytoplasmic NADH was able to rescue the growth of PEPCK depleted tumors, suggesting a problem in clearing cytoplasmic NADH. Consistent with this, blocking the glycerol-3-phosphate shuttle blocked tumor growth, as well as lowering ROS levels. This work suggests that proliferating CIN cells are particularly vulnerable to inhibition of PEPCK, or its metabolic network, because of their compromised redox status.


Assuntos
Neoplasias Encefálicas/patologia , Glicólise , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Animais , Modelos Animais de Doenças , Drosophila , Células Tumorais Cultivadas
15.
Oncotarget ; 7(39): 63913-63923, 2016 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-27590505

RESUMO

Chromosomal instability (CIN) refers to genomic instability in which cells have gained or lost chromosomes or chromosomal fragments. A high level of CIN is common in solid tumours and is associated with cancer drug resistance and poor prognosis. The impact of CIN-induced stress and the resulting cellular responses are only just beginning to emerge. Using proliferating tissue in Drosophila as a model, we found that autophagy is activated in CIN cells and is necessary for their survival. Specifically, increasing the removal of defective mitochondria by mitophagy is able to lower levels of reactive oxygen species and the resultant cellular damage that is normally seen in CIN cells. In response to DNA damage, CIN is increased in a positive feedback loop, and we found that increasing autophagy by Tor depletion could decrease the level of CIN in proliferating cells. These findings underline the importance of autophagy control in the development of CIN tumours.


Assuntos
Autofagia , Instabilidade Cromossômica , Animais , Apoptose , Proliferação de Células , Cromossomos/ultraestrutura , Dano ao DNA , Drosophila/genética , Proteínas de Drosophila/metabolismo , Resistência a Medicamentos , Microscopia de Fluorescência , Mitocôndrias/metabolismo , Estresse Oxidativo , Prognóstico , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
16.
Curr Drug Targets ; 17(2): 154-63, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25619750

RESUMO

The production of reactive oxygen species is a normal part of cell physiology, but many internal and external stimuli are able to trigger the production of excess levels of oxidants that are potentially damaging. The threat of oxidative damage is particularly significant to DNA, as damaged bases can interfere with replication to generate lasting mutations. Signalling through the JNK pathway is a key cellular response to oxidative damage. Depending on the intensity and duration of the damage signal, JNK signalling can lead to distinct alternative responses including DNA repair, anti-oxidant production or cell death. These responses are highly relevant to cancer therapy, as tumours are often under oxidative stress that produces elevated JNK levels and therapy often involves inducing DNA damage with the intention of driving cell death. In this review we examine the causes and consequences of JNK activation that relate to oxidative DNA damage, with a focus on the potential therapeutic implications.


Assuntos
Sistema de Sinalização das MAP Quinases , Neoplasias/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Dano ao DNA/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos
17.
Oncotarget ; 6(36): 38552-65, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26462024

RESUMO

Chromosomal instability (CIN) is a hallmark of cancer and has been implicated in cancer initiation, progression and the development of resistance to traditional cancer therapy. Here we identify a new property of CIN cells, showing that inducing CIN in proliferating Drosophila larval tissue leads to the activation of innate immune signalling in CIN cells. Manipulation of this immune pathway strongly affects the survival of CIN cells, primarily via JNK, which responds to both Toll and TNFα/Eiger. This pathway also activates Mmp1, which recruits hemocytes to the CIN tissue to provide local amplification of the immune response that is needed for effective elimination of CIN cells.


Assuntos
Instabilidade Cromossômica/imunologia , Receptores Toll-Like/imunologia , Animais , Apoptose/genética , Apoptose/imunologia , Morte Celular/genética , Morte Celular/imunologia , Drosophila , Imunidade Inata , Estresse Oxidativo/genética , Estresse Oxidativo/imunologia , Espécies Reativas de Oxigênio/imunologia , Transdução de Sinais , Receptores Toll-Like/genética
18.
Genes Chromosomes Cancer ; 54(12): 745-61, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26390919

RESUMO

Fragile site FRA16D exhibits DNA instability in cancer, resulting in diminished levels of protein from the WWOX gene that spans it. WWOX suppresses tumor growth by an undefined mechanism. WWOX participates in pathways involving aerobic metabolism and reactive oxygen species. WWOX comprises two WW domains as well as a short-chain dehydrogenase/reductase enzyme. Herein is described an in vivo genetic analysis in Drosophila melanogaster to identify functional interactions between WWOX and metabolic pathways. Altered WWOX levels modulate variable cellular outgrowths caused by genetic deficiencies of components of the mitochondrial respiratory complexes. This modulation requires the enzyme active site of WWOX, and the defective respiratory complex-induced cellular outgrowths are mediated by reactive oxygen species, dependent upon the Akt pathway and sensitive to levels of autophagy and hypoxia-inducible factor. WWOX is known to contribute to homeostasis by regulating the balance between oxidative phosphorylation and glycolysis. Reduction of WWOX levels results in diminished ability to respond to metabolic perturbation of normal cell growth. Thus, the ability of WWOX to facilitate escape from mitochondrial damage-induced glycolysis (Warburg effect) is, therefore, a plausible mechanism for its tumor suppressor activity.


Assuntos
Sítios Frágeis do Cromossomo , Proteínas de Drosophila/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Glicólise/genética , Mitocôndrias/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Domínio Catalítico , Proliferação de Células , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Homeostase , Redes e Vias Metabólicas/genética , Mitocôndrias/genética , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Fosforilação Oxidativa , Espécies Reativas de Oxigênio/metabolismo , Proteínas Supressoras de Tumor/genética , Oxidorredutase com Domínios WW
19.
Mediators Inflamm ; 2015: 369286, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25948885

RESUMO

The study of immune responses in Drosophila has already yielded significant results with impacts on our understanding of vertebrate immunity, such as the characterization of the Toll receptor. Several recent papers have focused on the humoral response to damage signals rather than pathogens, particularly damage signals from tumour-like tissues generated by loss of cell polarity or chromosomal instability. Both the triggers that generate this sterile inflammation and the systemic and local effects of it are only just beginning to be characterized in Drosophila. Here we review the molecular mechanisms that are known that give rise to the recruitment of Drosophila phagocytes, called hemocytes, as well as the signals, such as TNFα, that stimulated hemocytes emit at sites of perceived damage. The signalling consequences of inflammation, such as the activation of JNK, and the potential for modifying this response are also discussed.


Assuntos
Drosophila melanogaster/imunologia , Drosophila melanogaster/fisiologia , Hemócitos/citologia , Inflamação/imunologia , Fagócitos/citologia , Animais , Polaridade Celular , Cromossomos/ultraestrutura , Citocinas/metabolismo , Imunidade Humoral , Imunidade Inata , MAP Quinase Quinase 4/metabolismo , Necrose , Neoplasias/imunologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Cicatrização
20.
Cell Cycle ; 13(4): 622-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24335260

RESUMO

Chromosomal instability (CIN), as a common feature of tumors, represents a potential therapeutic target if ways can be found to specifically cause apoptosis in unstably dividing cells. We have previously shown that if signaling through the JNK pathway is reduced, apoptosis is triggered in models of chromosomal instability induced by loss of the spindle checkpoint. Here we identify components upstream and downstream of JNK that are able to mediate this effect, and test the involvement of p53 and DNA damage in causing apoptosis when JNK signaling is reduced in CIN cells. We show that cell cycle progression timing has a strong effect on the apoptosis seen when JNK signaling is reduced in genetically unstable cells: a shortened G 2 phase enhances the apoptosis, while lengthening G 2 rescues the JNK-deficient CIN cell death phenotype. Our findings suggest that chromosomal instability represents a significant stress to dividing cells, and that without JNK signaling, cells undergo apoptosis because they lack a timely and effective response to DNA damage.


Assuntos
Instabilidade Cromossômica/fisiologia , Drosophila/metabolismo , MAP Quinase Quinase 4/metabolismo , Sistema de Sinalização das MAP Quinases , Animais , Apoptose/fisiologia , Caspases/metabolismo , Dano ao DNA/fisiologia , Drosophila/genética , Proteínas de Drosophila/metabolismo , Fase G2/fisiologia , MAP Quinase Quinase 4/genética , Mitose , Proteína Supressora de Tumor p53/metabolismo
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