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2.
Front Sociol ; 7: 886548, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992509

RESUMO

Access to information about family planning (FP) continues to have financial, physical and social barriers among young women living in Kenya. This paper draws on social norms theory to explore how young women and their social networks access FP information on digital media (e.g., WhatsApp, websites). Qualitative phone interviews were conducted with 40 participants - young women, their partners and key influencers - in seven peri-urban wards in Nairobi, Kenya. Data were analyzed using thematic analysis. Findings suggested that young women, their partners and key influencers predominately accessed FP information online through their informal networks, but identified healthcare workers as the most trusted sources of FP information. In digital spaces, participants described being more comfortable sharing FP information as digital spaces allowed for greater privacy and reduced stigma to talk about FP openly. Our findings highlight the importance of digital media in disseminating FP information among young women and their networks, the differences in norms governing the acceptability to talk about FP online vs. in-person and the significance of targeting misinformation about FP in digital media spaces.

3.
Cell Death Differ ; 24(3): 500-510, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28186505

RESUMO

APO2L/TRAIL (TNF-related apoptosis-inducing ligand) induces death of tumor cells through two agonist receptors, TRAIL-R1 and TRAIL-R2. We demonstrate here that N-linked glycosylation (N-glyc) plays also an important regulatory role for TRAIL-R1-mediated and mouse TRAIL receptor (mTRAIL-R)-mediated apoptosis, but not for TRAIL-R2, which is devoid of N-glycans. Cells expressing N-glyc-defective mutants of TRAIL-R1 and mouse TRAIL-R were less sensitive to TRAIL than their wild-type counterparts. Defective apoptotic signaling by N-glyc-deficient TRAIL receptors was associated with lower TRAIL receptor aggregation and reduced DISC formation, but not with reduced TRAIL-binding affinity. Our results also indicate that TRAIL receptor N-glyc impacts immune evasion strategies. The cytomegalovirus (CMV) UL141 protein, which restricts cell-surface expression of human TRAIL death receptors, binds with significant higher affinity TRAIL-R1 lacking N-glyc, suggesting that this sugar modification may have evolved as a counterstrategy to prevent receptor inhibition by UL141. Altogether our findings demonstrate that N-glyc of TRAIL-R1 promotes TRAIL signaling and restricts virus-mediated inhibition.


Assuntos
Apoptose/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/toxicidade , Sequência de Aminoácidos , Animais , Linhagem Celular , Citomegalovirus/metabolismo , Glicosilação , Células HCT116 , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Mutagênese Sítio-Dirigida , Nanopartículas/química , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/deficiência , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Alinhamento de Sequência , Tunicamicina/toxicidade , Proteínas Virais/genética , Proteínas Virais/metabolismo
4.
Toxicol Lett ; 254: 1-7, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27084041

RESUMO

Zearalenone (ZEN) and Aflatoxin B1 (AFB1) are fungal secondary metabolites produced by Fusarium and Aspergillus genera, respectively. These mycotoxins are found world-wide as corn and wheat contaminants. AFB1 is probably the most toxic and carcinogenic mycotoxin. It has been demonstrated to be mutagenic, genotoxic, and hepatocarcinogenic. ZEN is a non-steroidal estrogenic mycotoxin that displays hepatotoxicity, immunotoxicity and genotoxicity. Its mutagenic and carcinogenic properties have so far remained controversial and questionable. Using the colon carcinoma cell line HCT116, we will show here that ZEN, at low concentrations, enhances cell proliferation, increases colony formation and fastens cell migration after wound healing. The highest effect of ZEN was observed at a concentration 10 times lower as compared to AFB1. Our findings suggest thus that this mycotoxin exhibits carcinogenesis-like properties in HCT116 cells.


Assuntos
Carcinógenos/toxicidade , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/patologia , Zearalenona/toxicidade , Relação Dose-Resposta a Droga , Células HCT116 , Humanos , Invasividade Neoplásica , Fatores de Tempo , Cicatrização/efeitos dos fármacos
5.
J Biochem Mol Toxicol ; 30(3): 128-35, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26849850

RESUMO

T-2 toxin and Ochratoxin A (OTA) are toxic secondary metabolites produced by various fungi, and together they contaminate feedstuffs worldwide. T-2 toxin and OTA may exert carcinogenic action in rodent. Despite the various in vivo experiments, carcinogenicity of these two mycotoxins has not yet been proven for human. In this current study, we proposed to investigate, in Human colon carcinoma cells and fetal lung fibroblast-like cells transfected with MYC, the effect of T-2 toxin and OTA on cell clonogenicity and cell migration. Results of the present investigation showed that T2-toxin as well as OTA has an important clonogenic effect in all cell lines, suggesting that these mycotoxins could promote the transcription of c-myc gene. Furthermore, T-2 toxin and OTA enhanced the migration effect of HCT116 cells at very low concentrations, proposing that these mycotoxins may exhibit carcinogenesis-like properties in the studied cells.


Assuntos
Movimento Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Pulmão/efeitos dos fármacos , Micotoxinas/toxicidade , Ocratoxinas/toxicidade , Toxina T-2/toxicidade , Aflatoxina B1/toxicidade , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Pulmão/citologia , Pulmão/embriologia , Cicatrização
6.
J Cardiothorac Vasc Anesth ; 29(5): 1236-47, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26119403

RESUMO

OBJECTIVES: The authors investigated whether zero-balance ultrafiltration (Z-BUF) during bypass significantly improves clinical and cost outcomes or biomarkers of kidney injury for patients with preoperative kidney impairment (estimated glomerular filtration rate [eGFR]<60 mL/minute) undergoing cardiac surgery. DESIGN: A single-center randomized controlled trial recruited, patients between 2010 and 2013, with a 12-months follow-up. SETTING: Hospital. PARTICIPANTS: One hundred ninety-nine patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). INTERVENTIONS: Patients were assigned randomly to receive zero-balance ultrafiltration (Z-BUF) or not, with stratification for degree of kidney dysfunction and diabetes. MEASUREMENTS AND MAIN RESULTS: The authors assessed clinical efficacy and kidney function biomarkers. Cumulative probability of discharge from the intensive care unit (ICU) was assessed by Kaplan-Meier plots and was found not to be significantly different between the two trial arms (p = 0.61). After adjusting for EuroSCORE, diabetes, eGFR, cardioplegia types and type of surgery in a Cox proportional hazard model, hazard ratios (HR) for ICU length of stay between the Z-BUF and no-Z-BUF groups was not significantly different: HR (95% CI): 0.89 (0.66, 1.20; p = 0.44). In contrast, significant reductions in postoperative chest infections and the composite of clinical endpoints (death, strokes, and myocardial infarctions) in the Z-BUF group were observed. In addition, Z-BUF significantly abrogated the rise in the kidney damage markers urinary NGAL/creatinine ratio, urea, creatinine and eGFR during CPB and adverse events risks. CONCLUSIONS: Z-BUF during bypass surgery is associated with significant reductions in morbidity and biomarkers of CPB-induced acute kidney injury soon after CPB, which are indicative of clearance of inflammatory/immune mediators from the circulation.


Assuntos
Injúria Renal Aguda/prevenção & controle , Procedimentos Cirúrgicos Cardíacos , Ponte Cardiopulmonar , Doença da Artéria Coronariana/cirurgia , Insuficiência Renal/terapia , Ultrafiltração/métodos , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Idoso , Idoso de 80 Anos ou mais , Doença da Artéria Coronariana/complicações , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Morbidade/tendências , Insuficiência Renal/complicações , Estudos Retrospectivos , Método Simples-Cego , Reino Unido/epidemiologia
7.
PLoS One ; 10(5): e0126526, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26010871

RESUMO

Ezrin belongs to the ERM (ezrin-radixin-moesin) protein family and has been demonstrated to regulate early steps of Fas receptor signalling in lymphoid cells, but its contribution to TRAIL-induced cell death regulation in adherent cancer cells remains unknown. In this study we report that regulation of FasL and TRAIL-induced cell death by ezrin is cell type dependant. Ezrin is a positive regulator of apoptosis in T-lymphoma cell line Jurkat, but a negative regulator in colon cancer cells. Using ezrin phosphorylation or actin-binding mutants, we provide evidence that negative regulation of death receptor-induced apoptosis by ezrin occurs in a cytoskeleton- and DISC-independent manner, in colon cancer cells. Remarkably, inhibition of apoptosis induced by these ligands was found to be tightly associated with regulation of ezrin phosphorylation on serine 66, the tumor suppressor gene WWOX and activation of PKA. Deficiency in WWOX expression in the liver cancer SK-HEP1 or the pancreatic Mia PaCa-2 cell lines as well as WWOX silencing or modulation of PKA activation by pharmacological regulators, in the colon cancer cell line SW480, abrogated regulation of TRAIL signalling by ezrin. Altogether our results show that death receptor pro-apoptotic signalling regulation by ezrin can occur downstream of the DISC in colon cancer cells.


Assuntos
Apoptose , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas do Citoesqueleto/metabolismo , Receptores de Morte Celular/metabolismo , Transdução de Sinais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Oxirredutases/metabolismo , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Oxidorredutase com Domínios WW , Receptor fas/metabolismo
8.
Cancer Lett ; 332(2): 141-50, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-21071136

RESUMO

Cellular-FLICE inhibitory protein (c-FLIP) is a key anti-apoptotic regulator that inhibits cell death mediated by the death receptors Fas, DR4, DR5, and TNF-R1. Three splice variants of c-FLIP function at the DISC level by blocking the processing and activation of procaspase-8 and -10. Overexpression of c-FLIP has been identified in many different tumour types, and its downregulation in vitro has been shown to restore apoptosis mediated by CD95L and TRAIL. c-FLIP therefore represents a promising target for cancer therapy. This review focuses on the molecular mechanisms that control c-FLIP expression and current research into inhibitors of the protein. Increasing evidence supports the investigation of c-FLIP as a therapeutic target to restore an apoptotic response in cancer cells.


Assuntos
Apoptose , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Antineoplásicos/farmacologia , Proteína Ligante Fas/metabolismo , Humanos , Ligantes , Neoplasias/patologia , Processamento de Proteína Pós-Traducional , RNA Interferente Pequeno/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transcrição Gênica
9.
Recent Pat Anticancer Drug Discov ; 6(3): 311-23, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21756247

RESUMO

The use of TRAIL/APO2L and monoclonal antibodies targeting TRAIL receptors for cancer therapy holds great promise, due to their ability to restore cancer cell sensitivity to apoptosis in association with conventional chemotherapeutic drugs in a large variety of tumors. TRAIL-induced cell death is tightly regulated right from the membrane and at the DISC (Death-Inducing Signaling Complex) level. The following patent and literature review aims to present and highlight recent findings of the deadly discussion that determines tumor cell fate upon TRAIL engagement.


Assuntos
Apoptose/fisiologia , Membrana Celular/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/fisiologia , Animais , Apoptose/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/fisiologia , Morte Celular/genética , Morte Celular/fisiologia , Membrana Celular/patologia , Humanos , Modelos Biológicos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
10.
PLoS One ; 6(5): e19679, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21625476

RESUMO

BACKGROUND: TRAIL/Apo2L is a pro-apoptotic ligand of the TNF family that engages the apoptotic machinery through two pro-apoptotic receptors, TRAIL-R1 and TRAIL-R2. This cell death program is tightly controlled by two antagonistic receptors, TRAIL-R3 and TRAIL-R4, both devoid of a functional death domain, an intracellular region of the receptor, required for the recruitment and the activation of initiator caspases. Upon TRAIL-binding, TRAIL-R4 forms a heteromeric complex with the agonistic receptor TRAIL-R2 leading to reduced caspase-8 activation and apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: We provide evidence that TRAIL-R4 can also exhibit, in a ligand independent manner, signaling properties in the cervical carcinoma cell line HeLa, through Akt. Ectopic expression of TRAIL-R4 in HeLa cells induced morphological changes, with cell rounding, loss of adherence and markedly enhanced cell proliferation in vitro and tumor growth in vivo. Disruption of the PI3K/Akt pathway using the pharmacological inhibitor LY294002, siRNA targeting the p85 regulatory subunit of phosphatidylinositol-3 kinase, or by PTEN over-expression, partially restored TRAIL-mediated apoptosis in these cells. Moreover, the Akt inhibitor, LY294002, restituted normal cell proliferation index in HeLa cells expressing TRAIL-R4. CONCLUSIONS/SIGNIFICANCE: Altogether, these results indicate that, besides its ability to directly inhibit TRAIL-induced cell death at the membrane, TRAIL-R4 can also trigger the activation of signaling pathways leading to cell survival and proliferation in HeLa cells. Our findings raise the possibility that TRAIL-R4 may contribute to cervical carcinogenesis.


Assuntos
Apoptose , Neoplasias Experimentais/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Chamariz do Fator de Necrose Tumoral/metabolismo , Animais , Western Blotting , Membrana Celular/metabolismo , Proliferação de Células , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Nus , Morfolinas/farmacologia , Neoplasias Experimentais/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo
11.
J Biol Chem ; 286(19): 17015-28, 2011 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-21393245

RESUMO

The inhibitor of apoptosis (IAP) proteins are important ubiquitin E3 ligases that regulate cell survival and oncogenesis. The cIAP1 and cIAP2 paralogs bear three N-terminal baculoviral IAP repeat (BIR) domains and a C-terminal E3 ligase RING domain. IAP antagonist compounds, also known as Smac mimetics, bind the BIR domains of IAPs and trigger rapid RING-dependent autoubiquitylation, but the mechanism is unknown. We show that RING dimerization is essential for the E3 ligase activity of cIAP1 and cIAP2 because monomeric RING mutants could not interact with the ubiquitin-charged E2 enzyme and were resistant to Smac mimetic-induced autoubiquitylation. Unexpectedly, the BIR domains inhibited cIAP1 RING dimerization, and cIAP1 existed predominantly as an inactive monomer. However, addition of either mono- or bivalent Smac mimetics relieved this inhibition, thereby allowing dimer formation and promoting E3 ligase activation. In contrast, the cIAP2 dimer was more stable, had higher intrinsic E3 ligase activity, and was not highly activated by Smac mimetics. These results explain how Smac mimetics promote rapid destruction of cIAP1 and suggest mechanisms for activating cIAP1 in other pathways.


Assuntos
Proteínas Inibidoras de Apoptose/química , Proteínas Inibidoras de Apoptose/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Apoptose , Biomimética , Dicroísmo Circular , Dimerização , Ativação Enzimática , Humanos , Lentivirus/genética , Camundongos , Mutagênese , Ligação Proteica , Estrutura Terciária de Proteína , Espalhamento de Radiação , Transdução de Sinais , Ubiquitina/química
12.
Front Oncol ; 1: 37, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22649762

RESUMO

First discovered in 1962, heat shock proteins (HSPs) are highly studied with about 35,500 publications on the subject to date. HSPs are highly conserved, function as molecular chaperones for a large panel of "client" proteins and have strong cytoprotective properties. Induced by many different stress signals, they promote cell survival in adverse conditions. Therefore, their roles have been investigated in several conditions and pathologies where HSPs accumulate, such as in cancer. Among the diverse mammalian HSPs, some members share several features that may qualify them as cancer biomarkers. This review focuses mainly on three inducible HSPs: HSP27, HPS70, and HSP90. Our survey of recent literature highlights some recurring weaknesses in studies of the HSPs, but also identifies findings that indicate that some HSPs have potential as cancer biomarkers for successful clinical applications.

13.
Cell Mol Life Sci ; 67(18): 3115-30, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20508968

RESUMO

TNF-related apoptosis-inducing ligand (TRAIL) and its receptors are attractive targets for anticancer therapy owing to their ability to trigger apoptosis selectively in cancer cells but not in normal cells. To date, many combinatorial strategies, such as chemotherapy or radiotherapy, have given encouraging results for overcoming TRAIL resistance in preclinical models. In this review, we provide an overview of the molecular mechanisms underlying sensitization to TRAIL-induced apoptosis by polyphenols. These naturally occurring compounds can restore tumor cell sensitivity to TRAIL-induced cell death with no apparent toxicity towards normal cells. Both extrinsic and intrinsic pathways can be modulated by polyphenols, the activation of which largely depends on the cell type, the particular polyphenolic compound, and the conditions of treatment. The large variety of polyphenol cellular targets could prove useful in circumventing TRAIL resistance. The relevance of these combined treatments for cancer therapy is discussed in the light of recent preclinical studies.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Flavonoides/farmacologia , Neoplasias/tratamento farmacológico , Fenóis/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Animais , Flavonoides/química , Flavonoides/classificação , Humanos , Camundongos , Fenóis/química , Fenóis/classificação , Polifenóis , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico
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