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1.
PLoS Med ; 19(4): e1003980, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35476675

RESUMO

BACKGROUND: We previously found that 25% of 1,017 randomized clinical trials (RCTs) approved between 2000 and 2003 were discontinued prematurely, and 44% remained unpublished at a median of 12 years follow-up. We aimed to assess a decade later (1) whether rates of completion and publication have increased; (2) the extent to which nonpublished RCTs can be identified in trial registries; and (3) the association between reporting quality of protocols and premature discontinuation or nonpublication of RCTs. METHODS AND FINDINGS: We included 326 RCT protocols approved in 2012 by research ethics committees in Switzerland, the United Kingdom, Germany, and Canada in this metaresearch study. Pilot, feasibility, and phase 1 studies were excluded. We extracted trial characteristics from each study protocol and systematically searched for corresponding trial registration (if not reported in the protocol) and full text publications until February 2022. For trial registrations, we searched the (i) World Health Organization: International Clinical Trial Registry Platform (ICTRP); (ii) US National Library of Medicine (ClinicalTrials.gov); (iii) European Union Drug Regulating Authorities Clinical Trials Database (EUCTR); (iv) ISRCTN registry; and (v) Google. For full text publications, we searched PubMed, Google Scholar, and Scopus. We recorded whether RCTs were registered, discontinued (including reason for discontinuation), and published. The reporting quality of RCT protocols was assessed with the 33-item SPIRIT checklist. We used multivariable logistic regression to examine the association between the independent variables protocol reporting quality, planned sample size, type of control (placebo versus other), reporting of any recruitment projection, single-center versus multicenter trials, and industry versus investigator sponsoring, with the 2 dependent variables: (1) publication of RCT results; and (2) trial discontinuation due to poor recruitment. Of the 326 included trials, 19 (6%) were unregistered. Ninety-eight trials (30%) were discontinued prematurely, most often due to poor recruitment (37%; 36/98). One in 5 trials (21%; 70/326) remained unpublished at 10 years follow-up, and 21% of unpublished trials (15/70) were unregistered. Twenty-three of 147 investigator-sponsored trials (16%) reported their results in a trial registry in contrast to 150 of 179 industry-sponsored trials (84%). The median proportion of reported SPIRIT items in included RCT protocols was 69% (interquartile range 61% to 77%). We found no variables associated with trial discontinuation; however, lower reporting quality of trial protocols was associated with nonpublication (odds ratio, 0.71 for each 10% increment in the proportion of SPIRIT items met; 95% confidence interval, 0.55 to 0.92; p = 0.009). Study limitations include that the moderate sample size may have limited the ability of our regression models to identify significant associations. CONCLUSIONS: We have observed that rates of premature trial discontinuation have not changed in the past decade. Nonpublication of RCTs has declined but remains common; 21% of unpublished trials could not be identified in registries. Only 16% of investigator-sponsored trials reported results in a trial registry. Higher reporting quality of RCT protocols was associated with publication of results. Further efforts from all stakeholders are needed to improve efficiency and transparency of clinical research.


Assuntos
Pesquisadores , Alemanha , Humanos , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Sistema de Registros
2.
Biochem Biophys Res Commun ; 471(1): 205-12, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26826385

RESUMO

Hypoxia promotes cancer progression, and metastasis. The major protein expressed in hypoxic solid cancer is hypoxia-inducible factor 1 (HIF1). We show that enhanced phosphorylation of a conventional protein kinase C isoform, PKCα, at threonine 638 (T(638)) by hypoxia-mimetic cobalt chloride induces HIF1α in nuclei of gastric epithelial cells (GECs). Moreover, phospho-T(638)-PKCα (P-PKCα) interacts with p300-HIF1α complex in the nuclei of hypoxic GECs and PKCα phosphorylation at T(638) enhances transcriptional activity of HIF1α. High P-PKCα expression in neoplastic gastric cancer biopsy samples as compared to nonneoplastic samples suggests that P-PKCα might act as an indicator of gastric cancer progression.


Assuntos
Núcleo Celular/metabolismo , Cobalto/administração & dosagem , Mucosa Gástrica/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína Quinase C-alfa/metabolismo , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Mucosa Gástrica/efeitos dos fármacos , Humanos , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia
3.
Clin Cancer Res ; 30(3): 586-599, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-37992313

RESUMO

PURPOSE: Myeloproliferative neoplasms (MPN) dysregulate JAK2 signaling. Because clinical JAK2 inhibitors have limited disease-modifying effects, type II JAK2 inhibitors such as CHZ868 stabilizing inactive JAK2 and reducing MPN clones, gain interest. We studied whether MPN cells escape from type ll inhibition. EXPERIMENTAL DESIGN: MPN cells were continuously exposed to CHZ868. We used phosphoproteomic analyses and ATAC/RNA sequencing to characterize acquired resistance to type II JAK2 inhibition, and targeted candidate mediators in MPN cells and mice. RESULTS: MPN cells showed increased IC50 and reduced apoptosis upon CHZ868 reflecting acquired resistance to JAK2 inhibition. Among >2,500 differential phospho-sites, MAPK pathway activation was most prominent, while JAK2-STAT3/5 remained suppressed. Altered histone occupancy promoting AP-1/GATA binding motif exposure associated with upregulated AXL kinase and enriched RAS target gene profiles. AXL knockdown resensitized MPN cells and combined JAK2/AXL inhibition using bemcentinib or gilteritinib reduced IC50 to levels of sensitive cells. While resistant cells induced tumor growth in NOD/SCID gamma mice despite JAK2 inhibition, JAK2/AXL inhibition largely prevented tumor progression. Because inhibitors of MAPK pathway kinases such as MEK are clinically used in other malignancies, we evaluated JAK2/MAPK inhibition with trametinib to interfere with AXL/MAPK-induced resistance. Tumor growth was halted similarly to JAK2/AXL inhibition and in a systemic cell line-derived mouse model, marrow infiltration was decreased supporting dependency on AXL/MAPK. CONCLUSIONS: We report on a novel mechanism of AXL/MAPK-driven escape from type II JAK2 inhibition, which is targetable at different nodes. This highlights AXL as mediator of acquired resistance warranting inhibition to enhance sustainability of JAK2 inhibition in MPN.


Assuntos
Aminopiridinas , Benzimidazóis , Inibidores de Janus Quinases , Transtornos Mieloproliferativos , Animais , Camundongos , Linhagem Celular Tumoral , Inibidores de Proteínas Quinases/farmacologia , Camundongos Endogâmicos NOD , Camundongos SCID , Janus Quinase 2/metabolismo , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/metabolismo
4.
CNS Neurol Disord Drug Targets ; 22(5): 761-773, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35431004

RESUMO

BACKGROUND: Twenty million Americans suffer from peripheral nerve injury (PNI) and approximately $150 billion is spent annually in the United States for the treatment of nerve injuries. Moreover, 50,000 cases of PNI repairs are performed annually in the United States, with even less than 42% experiencing satisfactory sensory recovery. Available therapies control painful symptoms but do not treat axonal degeneration or neuronal cell death. Peripheral nerve fibrosis (PNF) associated with chronic inflammation, perineural adhesions, and scarring is often reported in patients with nerve injury. Unfortunately, post-surgical adhesions and fibrosis often lead to aberrated wound healing and impairment of nerve functions. Various treatment strategies have been attempted, including the use of grafts and biomaterials; however, few appear promising. OBJECTIVE: L-Alanyl-L-Glutamine (L-Ala-L-Gln) was reported to protect the lung from sepsisinduced injury and play an immunomodulatory role in stress and fibrosis. This study aimed to examine the potential anti-fibrotic effects of L-Ala-L-Gln in an in vitro model of neural fibrosis. METHODS: Primary fibroblasts isolated from rat sciatic nerve were exposed to chronic (48 h) and episodic (2 h) hypoxic conditions. Cultures were then treated for 48 h with various concentrations of L-Ala-L-Gln (0, 1, 10, and 100 mM). The expression of hypoxic and pro-fibrotic markers in the different culture conditions was assessed by immunocytochemistry and western blot analyses. Quantitative phosphor-proteomic profiling was performed to investigate mechanistically the impact of L-Ala- L-Gln on collagen biosynthesis and hypoxia-driven tissue fibrosis in vitro. RESULTS: In protein expression assays, L-Ala-L-Gln significantly reduced markers related to the cellular response to hypoxia, in particular HIF-1 signaling. L-Ala-L-Gln also significantly reduced the expression of pro-fibrotic and cell-adhesion-inducing factors. Phospho-proteomic data indicated that L-Ala-L-Gln modulates several pro-fibrotic factors and associated pathways. CONCLUSION: Altogether, our data demonstrate that L-Ala-L-Gln efficiently suppresses hypoxiamediated fibrotic processes at different concentrations in rat primary fibroblasts. Thus, L-Ala-L-Gln presents a high potential therapeutic value as an antifibrotic pharmaceutical agent for the treatment of neural fibrosis.


Assuntos
Proteômica , Nervo Isquiático , Ratos , Animais , Fibrose , Fenótipo , Hipóxia/patologia , Fibroblastos , Dipeptídeos/farmacologia
5.
J Clin Epidemiol ; 149: 45-52, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35654268

RESUMO

OBJECTIVES: Availability of randomized controlled trial (RCT) protocols is essential for the interpretation of trial results and research transparency. STUDY DESIGN AND SETTING: In this study, we determined the availability of RCT protocols approved in Switzerland, Canada, Germany, and the United Kingdom in 2012. For these RCTs, we searched PubMed, Google Scholar, Scopus, and trial registries for publicly available protocols and corresponding full-text publications of results. We determined the proportion of RCTs with (1) publicly available protocols, (2) publications citing the protocol, and (3) registries providing a link to the protocol. A multivariable logistic regression model explored factors associated with protocol availability. RESULTS: Three hundred twenty-six RCTs were included, of which 118 (36.2%) made their protocol publicly available; 56 (47.6% 56 of 118) provided as a peer-reviewed publication and 48 (40.7%, 48 of 118) provided as supplementary material. A total of 90.9% (100 of 110) of the protocols were cited in the main publication, and 55.9% (66 of 118) were linked in the clinical trial registry. Larger sample size (>500; odds ratio [OR] = 5.90, 95% confidence interval [CI], 2.75-13.31) and investigator sponsorship (OR = 1.99, 95% CI, 1.11-3.59) were associated with increased protocol availability. Most protocols were made available shortly before the publication of the main results. CONCLUSION: RCT protocols should be made available at an early stage of the trial.


Assuntos
Pesquisadores , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Alemanha , Razão de Chances , Tamanho da Amostra , Sistema de Registros
6.
BMJ Open ; 12(5): e053417, 2022 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-35613804

RESUMO

OBJECTIVES: Comprehensive protocols are key for the planning and conduct of randomised clinical trials (RCTs). Evidence of low reporting quality of RCT protocols led to the publication of the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist in 2013. We aimed to examine the quality of reporting of RCT protocols from three countries before and after the publication of the SPIRIT checklist. DESIGN: Repeated cross sectional study. SETTING: Swiss, German and Canadian research ethics committees (RECs). PARTICIPANTS: RCT protocols approved by RECs in 2012 (n=257) and 2016 (n=292). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the proportion of reported SPIRIT items per protocol and the proportion of trial protocols reporting individual SPIRIT items. We compared these outcomes in protocols approved in 2012 and 2016, and built regression models to explore factors associated with adherence to SPIRIT. For each protocol, we also extracted information on general trial characteristics and assessed whether individual SPIRIT items were reported RESULTS: The median proportion of reported SPIRIT items among RCT protocols showed a non-significant increase from 72% (IQR, 63%-79%) in 2012 to 77% (IQR, 68%-82%) in 2016. However, in a preplanned subgroup analysis, we detected a significant improvement in investigator-sponsored protocols: the median proportion increased from 64% (IQR, 55%-72%) in 2012 to 76% (IQR, 64%-83%) in 2016, while for industry-sponsored protocols median adherence was 77% (IQR 72%-80%) for both years. The following trial characteristics were independently associated with lower adherence to SPIRIT: single-centre trial, no support from a clinical trials unit or contract research organisation, and investigator-sponsorship. CONCLUSIONS: In 2012, industry-sponsored RCT protocols were reported more comprehensively than investigator-sponsored protocols. After publication of the SPIRIT checklist, investigator-sponsored protocols improved to the level of industry-sponsored protocols, which did not improve.


Assuntos
Comitês de Ética em Pesquisa , Canadá , Estudos Transversais , Alemanha , Humanos , Suíça
7.
JAMA Netw Open ; 4(11): e2128898, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34724557

RESUMO

Importance: Clinical trial registries are important for gaining an overview of ongoing research efforts and for deterring and identifying publication bias and selective outcome reporting. The reliability of the information in trial registries is uncertain. Objective: To assess the reliability of information across registries for trials with multiple registrations. Evidence Review: For this systematic review, 360 protocols of randomized clinical trials (RCTs) approved by research ethics committees in Switzerland, the UK, Canada, and Germany in 2012 were evaluated. Clinical trial registries were searched from March to September 2019 for corresponding registrations of these RCTs. For RCTS that were recorded in more than 1 clinical trial registry, key trial characteristics that should be identical among all trial registries (ie, sponsor, funding source, primary outcome, target sample size, trial status, date of first patient enrollment, results available, and main publication indexed) were extracted in duplicate. Agreement between the different trial registries for these key characteristics was analyzed descriptively. Data analyses were conducted from May 1 to November 30, 2020. Representatives from clinical trial registries were interviewed to discuss the study findings between February 1 and March 31, 2021. Findings: The analysis included 197 RCTs registered in more than 1 trial registry (151 in 2 registries and 46 in 3 registries), with 188 trials in ClinicalTrials.gov, 185 in the European Union Drug Regulating Authorities Clinical Trials Database (EudraCT), 20 in ISRCTN, and 47 in other registries. The agreement of key information across all registries was as follows: 178 of 197 RCTs (90%; 95% CI, 85%-94%) for sponsor, 18 of 20 (90%; 95% CI, 68%-99%) for funding source (funding was not reported on ClinicalTrials.gov), 154 of 197 (78%; 95% CI, 72%-84%) for primary outcome, 90 of 197 (46%; 95% CI, 39%-53%) for trial status, 122 of 194 (63%; 95% CI, 56%-70%) for target sample size, and 43 of 57 (75%; 95% CI, 62%-86%) for the date of first patient enrollment when the comparison time was increased to 30 days (date of first patient enrollment was not reported on EudraCT). For results availability in trial registries, agreement was 122 of 197 RCTs (62%; 95% CI, 55%-69%) for summary data reported in the registry and 91 of 197 (46%; 95% CI, 39%-53%) for whether a published article with the main results was indexed. Different legal requirements were stated as the main reason for inconsistencies by representatives of clinical trial registries. Conclusions and Relevance: In this systematic review, for a substantial proportion of registered RCTs, information about key trial characteristics was inconsistent across trial registries, raising concerns about the reliability of the information provided in these registries. Further harmonization across clinical trial registries may be necessary to increase their usefulness.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Sistema de Registros/estatística & dados numéricos , Sistema de Registros/normas , Reprodutibilidade dos Testes , Atitude , Austrália , Canadá , Ensaios Clínicos como Assunto/psicologia , Alemanha , Humanos , Índia , Entrevistas como Assunto , Nova Zelândia , Pesquisadores/psicologia , Suíça , Reino Unido , Estados Unidos
8.
J Clin Epidemiol ; 139: 340-349, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34029678

RESUMO

OBJECTIVES: To investigate the adherence of randomised controlled trial (RCT) protocols evaluating non-regulated interventions (including dietary interventions, surgical procedures, behavioural and lifestyle interventions, and exercise programmes) in comparison with regulated interventions to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 Statement. METHODS: We conducted a repeated cross-sectional investigation in a random sample of RCT protocols approved in 2012 (n = 257) or 2016 (n = 292) by research ethics committees in Switzerland, Germany, or Canada. We investigated the proportion of accurately reported SPIRIT checklist items in protocols of trials with non-regulated as compared to regulated interventions. RESULTS: Overall, 131 (24%) of trial protocols tested non-regulated interventions. In 2012, the median proportion of SPIRIT items reported in these protocols (59%, interquartile range [IQR], 53%-69%) was lower than in protocols with regulated interventions (median, 74%, IQR, 66%-80%). In 2016, the reporting quality of protocols with non-regulated interventions (median, 75%, IQR, 62%-83%) improved to the level of regulated intervention protocols, which had not changed on average. CONCLUSIONS: Reporting of RCT protocols evaluating non-regulated interventions improved between 2012 and 2016, although remained suboptimal. SPIRIT recommendations need to be further endorsed by researchers, ethics committees, funding agencies, and journals to optimize reporting of RCT protocols.


Assuntos
Protocolos de Ensaio Clínico como Assunto , Confiabilidade dos Dados , Fidelidade a Diretrizes/estatística & dados numéricos , Guias como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Projetos de Pesquisa/estatística & dados numéricos , Projetos de Pesquisa/normas , Canadá , Estudos Transversais , Comitês de Ética em Pesquisa , Geografia , Alemanha , Humanos , Suíça
9.
CNS Neurol Disord Drug Targets ; 19(8): 560-571, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32713338

RESUMO

The concepts of the neurobiology of nerve injury, fibrosis and regeneration are critical. Millions of people worldwide are affected every year by traumatic and non-traumatic forms of injury to the spinal cord or the peripheral nerves that cause huge socioeconomic burdens. Innumerable studies over the last few decades have studied the disease pathogenesis. Also, several strategies and techniques have undertaken to repair injuries in the PNS and CNS, but all have resulted in suboptimal functional outcomes. In this review, we have provided a general description of injury-induced scarring and fibrosis in the PNS and CNS. We also discuss the important signaling factors and mechanistic pathways that regulate the disease pathogenesis. We further discuss the current paradigms that suggest the involvement of essential factors in and during disease progression. We believe that readers and researchers will gain key insights into how fibrosis regulates the regenerative process in the PNS and CNS. We hope this review will help clinicians and scientists to address an unmet medical need and direct further studies towards the identification of better therapeutic approaches.


Assuntos
Sistema Nervoso Central/patologia , Regeneração Nervosa , Nervos Periféricos/patologia , Animais , Axônios/fisiologia , Fibrose , Humanos , Traumatismos dos Nervos Periféricos/terapia , Medula Espinal/patologia
10.
Trials ; 21(1): 896, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33115541

RESUMO

BACKGROUND: Clearly structured and comprehensive protocols are an essential component to ensure safety of participants, data validity, successful conduct, and credibility of results of randomized clinical trials (RCTs). Funding agencies, research ethics committees (RECs), regulatory agencies, medical journals, systematic reviewers, and other stakeholders rely on protocols to appraise the conduct and reporting of RCTs. In response to evidence of poor protocol quality, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guideline was published in 2013 to improve the accuracy and completeness of clinical trial protocols. The impact of these recommendations on protocol completeness and associations between protocol completeness and successful RCT conduct and publication remain uncertain. OBJECTIVES AND METHODS: Aims of the Adherence to SPIrit REcommendations (ASPIRE) study are to investigate adherence to SPIRIT checklist items of RCT protocols approved by RECs in the UK, Switzerland, Germany, and Canada before (2012) and after (2016) the publication of the SPIRIT guidelines; determine protocol features associated with non-adherence to SPIRIT checklist items; and assess potential differences in adherence across countries. We assembled an international cohort of RCTs based on 450 protocols approved in 2012 and 402 protocols approved in 2016 by RECs in Switzerland, the UK, Germany, and Canada. We will extract data on RCT characteristics and adherence to SPIRIT for all included protocols. We will use multivariable regression models to investigate temporal changes in SPIRIT adherence, differences across countries, and associations between SPIRIT adherence of protocols with RCT registration, completion, and publication of results. We plan substudies to examine the registration, premature discontinuation, and non-publication of RCTs; the use of patient-reported outcomes in RCT protocols; SPIRIT adherence of RCT protocols with non-regulated interventions; the planning of RCT subgroup analyses; and the use of routinely collected data for RCTs. DISCUSSION: The ASPIRE study and associated substudies will provide important information on the impact of measures to improve the reporting of RCT protocols and on multiple aspects of RCT design, trial registration, premature discontinuation, and non-publication of RCTs observing potential changes over time.


Assuntos
Protocolos de Ensaio Clínico como Assunto , Estudos Transversais , Canadá , Comitês de Ética em Pesquisa , Alemanha , Humanos , Suíça
11.
J Clin Invest ; 129(4): 1596-1611, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30730307

RESUMO

Constitutive JAK2 signaling is central to myeloproliferative neoplasm (MPN) pathogenesis and results in activation of STAT, PI3K/AKT, and MEK/ERK signaling. However, the therapeutic efficacy of current JAK2 inhibitors is limited. We investigated the role of MEK/ERK signaling in MPN cell survival in the setting of JAK inhibition. Type I and II JAK2 inhibition suppressed MEK/ERK activation in MPN cell lines in vitro, but not in Jak2V617F and MPLW515L mouse models in vivo. JAK2 inhibition ex vivo inhibited MEK/ERK signaling, suggesting that cell-extrinsic factors maintain ERK activation in vivo. We identified PDGFRα as an activated kinase that remains activated upon JAK2 inhibition in vivo, and PDGF-AA/PDGF-BB production persisted in the setting of JAK inhibition. PDGF-BB maintained ERK activation in the presence of ruxolitinib, consistent with its function as a ligand-induced bypass for ERK activation. Combined JAK/MEK inhibition suppressed MEK/ERK activation in Jak2V617F and MPLW515L mice with increased efficacy and reversal of fibrosis to an extent not seen with JAK inhibitors. This demonstrates that compensatory ERK activation limits the efficacy of JAK2 inhibition and dual JAK/MEK inhibition provides an opportunity for improved therapeutic efficacy in MPNs and in other malignancies driven by aberrant JAK-STAT signaling.


Assuntos
Neoplasias Hematológicas/tratamento farmacológico , Janus Quinase 2/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mutação de Sentido Incorreto , Transtornos Mieloproliferativos/tratamento farmacológico , Proteínas de Neoplasias/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Substituição de Aminoácidos , Animais , Becaplermina/genética , Becaplermina/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Neoplasias Hematológicas/enzimologia , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Transtornos Mieloproliferativos/enzimologia , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/patologia , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de Trombopoetina/genética , Receptores de Trombopoetina/metabolismo
12.
Int J Biochem Cell Biol ; 82: 28-40, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27890795

RESUMO

Hypoxia enhances immortality and metastatic properties of solid tumors. Deregulation of histone acetylation has been associated with several metastatic cancers but its effect on hypoxic responses of cancer cells is not known. This study aimed at understanding the effectiveness of the hydrazinocurcumin, CTK7A, an inhibitor of p300 lysine/histone acetyltransferase (KAT/HAT) activity, in inducing apoptosis of gastric cancer cells (GCCs) exposed to cobalt chloride (CoCl2), a hypoxia-mimetic chemical, or 1% O2. Here, we show that CTK7A-induced hydrogen peroxide (H2O2) generation in CoCl2-exposed and invasive gastric cancer cells (GCCs) leads to p38 MAPK-mediated Noxa expression and thereafter, mitochondrial apoptotic events. Noxa induction in normal immortalized gastric epithelial cells after CTK7A and hypoxia-exposure is remarkably less in comparison to similarly-treated GCCs. Moreover, hypoxia-exposed GCCs, which have acquired invasive properties, become apoptotic after CTK7A treatment to a significantly higher extent than normoxic cells. Thus, we show the potential of CTK7A in sensitizing hypoxic and metastatic GCCs to apoptosis induction.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Curcumina/análogos & derivados , Proteína p300 Associada a E1A/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Hidrazinas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Neoplasias Gástricas/tratamento farmacológico , Acetilação/efeitos dos fármacos , Antineoplásicos/efeitos adversos , Antineoplásicos/química , Linhagem Celular Transformada , Linhagem Celular Tumoral , Cobalto/farmacologia , Curcumina/efeitos adversos , Curcumina/química , Curcumina/farmacologia , Proteína p300 Associada a E1A/metabolismo , Inibidores Enzimáticos/efeitos adversos , Mucosa Gástrica/citologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Hidrazinas/efeitos adversos , Hidrazinas/química , Peróxido de Hidrogênio/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Invasividade Neoplásica/patologia , Invasividade Neoplásica/prevenção & controle , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/metabolismo , Solubilidade , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Hipóxia Tumoral/efeitos dos fármacos
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