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ABSTRACTOpportunistic infections (OIs) are the primary cause of HIV-related morbidity and mortality. To reduce the risk, the ART eligibility criteria were revised to start treatment before advanced disease onset. We evaluated the effect of 2014 HIV clinical guideline changes in Uganda on opportunistic infections and survival among Youth Living with HIV (YLWH). This retrospective cohort analysis used administrative data from the District Health Information System (DHIS2) and the national referral hospital, to compare YLWH, 15-24 years old, who started ART pre-guideline (January 2012-June 2014) and post-guideline (July 2014-December 2016). We assessed the effect using multivariable logistic and Cox Proportional Hazards regression models, respectively. Post-guideline youth had 18% and 30% lower adjusted odds of having an OI at 6 (aOR: 0.82, 95%CI: 0.67, 0.99), and 12 months (aOR: 0.70, 95%CI: 0.58, 0.85) after ART initiation, compared to pre-guideline youth. No significant differences were observed in survival probabilities (Z = 2.56, P-value = 0.11) and adjusted hazard ratios (aHR: 1.55, 95%CI: 0.46, 5.28). Early ART initiation reduced the risk of OIs among YLWH. However, given the existence of geographical and clinical variations in the endemicity, morbidity and mortality associated with different OIs, additional research is still needed.
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Fármacos Anti-HIV , Infecções por HIV , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Humanos , Avaliação de Resultados em Cuidados de Saúde , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Uganda/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Poly(ADP-ribose) polymerase inhibitors (PARPis) are U.S. Food and Drug Administration (FDA) approved for treatment of BRCA-mutated metastatic breast cancer. Furthermore, the BROCADE studies demonstrated benefit of adding an oral PARPi, veliparib, to carboplatin and paclitaxel in patients with metastatic breast cancer harboring BRCA mutation. Given multiple possible dosing schedules and the potential benefit of this regimen for patients with defective DNA repair beyond BRCA, we sought to find the recommended phase II dose (RP2D) and schedule of veliparib in combination with carboplatin in patients with advanced breast cancer, either triple-negative (TNBC) or hormone receptor (HR)-positive, human epidermal growth receptor 2 (HER2) negative with defective Fanconi anemia (FA) DNA-repair pathway based on FA triple staining immunofluorescence assay. MATERIALS AND METHODS: Patients received escalating doses of veliparib on a 7-, 14-, or 21-day schedule with carboplatin every 3 weeks. Patients underwent [18]fluoro-3'-deoxythymidine (18 FLT) positron emission tomography (PET) imaging. RESULTS: Forty-four patients (39 TNBC, 5 HR positive/HER2 negative with a defective FA pathway) received a median of 5 cycles (range 1-36). Observed dose-limiting toxicities were grade (G) 4 thrombocytopenia (n = 4), G4 neutropenia (n = 1), and G3 akathisia (n = 1). Common grade 3-4 toxicities included thrombocytopenia, lymphopenia, neutropenia, anemia, and fatigue. Of the 43 patients evaluable for response, 18.6% achieved partial response and 48.8% had stable disease. Median progression-free survival was 18.3 weeks. RP2D of veliparib was established at 250 mg twice daily on days 1-21 along with carboplatin at area under the curve 5. Patients with partial response had a significant drop in maximum standard uptake value (SUVmax ) of target lesions between baseline and early in cycle 1 based on 18 FLT-PET (day 7-21; ptrend = .006). CONCLUSION: The combination of continuous dosing of veliparib and every-3-week carboplatin demonstrated activity and an acceptable toxicity profile. Decrease in SUVmax on 18 FLT-PET scan during the first cycle of this therapy can identify patients who are likely to have a response. IMPLICATIONS FOR PRACTICE: The BROCADE studies suggest that breast cancer patients with BRCA mutation benefit from addition of veliparib to carboplatin plus paclitaxel. This study demonstrates that a higher dose of veliparib is tolerable and active in combination with carboplatin alone. With growing interest in imaging-based early response assessment, the authors demonstrate that decrease in [18]fluoro-3'-deoxythymidine positron emission tomography (FLT-PET) SUVmax during cycle 1 of therapy is associated with response. Collectively, this study established a safety profile of veliparib and carboplatin in advanced breast cancer while also providing additional data on the potential for FLT-PET imaging modality in monitoring therapy response.
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Neoplasias da Mama , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzimidazóis , Biomarcadores , Neoplasias da Mama/tratamento farmacológico , Carboplatina/uso terapêutico , Feminino , Humanos , Tomografia por Emissão de PósitronsRESUMO
BACKGROUND: To assess metastatic breast cancer (MBC) patient psychological factors, perceptions, and comprehension of tumor genomic testing. METHODS: In a prospective, single institution, single-arm trial, patients with MBC underwent next-generation sequencing at study entry with sequencing results released at progression. Patients who completed surveys before undergoing sequencing were included in the present secondary analysis (n = 58). We administered four validated psychosocial measures: Center for Epidemiologic Studies Depression Scale, Beck Anxiety Inventory, Trust in Physician Scale, and Communication and Attitudinal Self-Efficacy scale for Cancer. Genetic comprehension was assessed using 7-question objective and 6-question subjective measures. Longitudinal data were assessed (n = 40) using paired Wilcoxon signed rank and McNemar's test of agreement. RESULTS: There were no significant differences between the beginning and end of study in depression, anxiety, physician trust, or self-efficacy (median time on study: 7.6 months). Depression and anxiety were positively associated with each other and both negatively associated with self-efficacy. Self-efficacy decreased from pre- to post-genomic testing (p = 0.05). Objective genetics comprehension did not significantly change from pre- to post-genomic testing, but patients expressed increased confidence in their ability to teach others about genetics (p = 0.04). Objective comprehension was significantly lower in non-white patients (p = 0.02) and patients with lower income (p = 0.04). CONCLUSIONS: This is the only study, to our knowledge, to longitudinally evaluate multiple psychological metrics in MBC as patients undergo tumor genomic testing. Overall, psychological dimensions remained stable over the duration of tumor genomic testing. Among patients with MBC, depression and anxiety metrics were negatively correlated with patient self-efficacy. Patients undergoing somatic genomic testing had limited genomic knowledge, which varied by demographic groups and may warrant additional educational intervention. CLINICAL TRIAL INFORMATION: NCT01987726, registered November 13, 2013.
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Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Técnicas de Apoio para a Decisão , Testes Genéticos/métodos , Conhecimentos, Atitudes e Prática em Saúde , Mutação , Percepção , Idoso , Neoplasias da Mama/psicologia , Neoplasias da Mama/terapia , Terapia Combinada , Feminino , Seguimentos , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Educação de Pacientes como Assunto , Prognóstico , Estudos ProspectivosRESUMO
Loss to follow-up (LTFU) is a critical factor in determining clinical outcomes in HIV treatment programs. Identifying modifiable factors of LTFU is fundamental for designing effective patient-retention interventions. We analyzed factors contributing to children LTFU from a treatment program to identify those that can be modified. A case-control study involving 313 children was used to compare the sociodemographic and clinical characteristics of children LTFU (cases) with those remaining in care (controls) at a large pediatric HIV care setting in Botswana. We traced children through caregiver contacts and those we found, we conducted structured interviews with patients' caregivers. Children <5 years were nearly twice as likely as older children to be LTFU (57·8% versus 30·9%, p <0 .01). Approximately half (47·6%, n = 51) of LTFU patients failed to further engage in care after just one clinic visit, as compared to less than 1% (n = 2) in the control group (p < 0.01). Children LTFU were more likely than controls to have advanced disease, greater immunosuppression, and not to be receiving antiretroviral therapy. Among interviewed patient caregivers, psychosocial factors (e.g., stigma, religious beliefs, child rebellion, disclosure of HIV status) were characteristics of patients LTFU, but not of controls. Socioeconomic factors (e.g., lack of transportation, school-related activities, forgetting appointments) were cited predominantly by the controls. Pediatric patients and their caregivers need to be targeted and engaged at their initial clinic visit, with special attention to children <5 years. Possible interventions include providing psychosocial support for issues that deter patients from engaging with The Clinic. Collaboration with community-based organizations focused on reducing stigma may be useful in addressing these complex issues.
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Infecções por HIV/tratamento farmacológico , Perda de Seguimento , Aceitação pelo Paciente de Cuidados de Saúde , Adolescente , Botsuana , Cuidadores , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Infecções por HIV/imunologia , Humanos , Lactente , Masculino , Religião , Índice de Gravidade de Doença , Estigma Social , Fatores Socioeconômicos , Fatores de Tempo , Meios de Transporte , Revelação da VerdadeRESUMO
Thanks to the development of antiretroviral drugs and the implementation of routine perinatal prophylaxis, primarily containing zidovudine, modern-day rates of perinatal transmission of HIV are very low in developed countries. We present a case of perinatal transmission of HIV with extensive nucleoside reverse transcriptase inhibitor resistance as a reminder that perinatal transmission of resistance mutations can occur. This case calls for further investigation into the utility of using genotype to determine neonatal prophylaxis in the setting of maternal HIV drug resistance.
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Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral , Infecções por HIV/transmissão , HIV-1/efeitos dos fármacos , Transmissão Vertical de Doenças Infecciosas , Adulto , Fármacos Anti-HIV/uso terapêutico , Feminino , Genótipo , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Humanos , Recém-Nascido , Masculino , Mães , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Estados UnidosRESUMO
Background: Influenza is one of the most common causes of acute respiratory infections in children; its complications are a leading cause of morbidity and mortality. There is a paucity of pediatric data on influenza disparities among racial/ethnic minorities. Our study assesses if there are racial/ethnic differences in hospitalizations and mortality in children infected with influenza. Methods: This was a retrospective cohort study using the National Inpatient Sample (NIS) from January 1, 2008 to December 31, 2017. We included children 18 years and younger hospitalized with a primary or secondary diagnosis of influenza or its subtypes. We generated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to evaluate the associations between patient characteristics and influenza hospitalizations and influenza-related mortality. Results: There were 226,535 (0.04%) influenza-associated hospitalizations. When compared with non-Hispanic (NH) White children, minority children were more likely to be hospitalized with an influenza diagnosis [Hispanics (aOR = 1.25; 95% CI, 1.17 to 1.33), NH-Blacks (aOR = 1.21, 95% CI, 1.17 to 1.33) and NH-Others group (aOR = 1.11; 95% CI, 1.04 to 1.19)]. There was no racial/ethnic difference in mortality. Conclusions: Minority children experienced a higher likelihood of influenza-associated hospitalizations but not mortality. Further research is needed to reduce the racial/ethnic disparities of influenza's impact.
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Influenza Humana , Criança , Etnicidade , Hospitalização , Humanos , Influenza Humana/epidemiologia , Grupos Raciais , Estudos RetrospectivosRESUMO
Past studies have shown that activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK is a common cause for resistance of melanoma cells to death receptor-mediated or mitochondria-mediated apoptosis. We report in this study that inhibition of the MEK/ERK pathway also sensitizes melanoma cells to endoplasmic reticulum (ER) stress-induced apoptosis, and this is mediated, at least in part, by caspase-4 activation and is associated with inhibition of the ER chaperon glucose-regulated protein 78 (GRP78) expression. Treatment with the ER stress inducer tunicamycin or thapsigargin did not induce significant apoptosis in the majority of melanoma cell lines, but resistance to these agents was reversed by the MEK inhibitor U0126 or MEK1 small interfering RNA (siRNA). Induction of apoptosis by ER stress when MEK was inhibited was caspase dependent with caspase-4, caspase-9, and caspase-3 being involved. Caspase-4 seemed to be the apical caspase in that caspase-4 activation occurred before activation of caspase-9 and caspase-3 and that inhibition of caspase-4 by a specific inhibitor or siRNA blocked activation of caspase-9 and caspase-3, whereas inhibition of caspase-9 or caspase-3 did not inhibit caspase-4 activation. Moreover, overexpression of Bcl-2 inhibited activation of caspase-9 and caspase-3 but had minimal effect on caspase-4 activation. Inhibition of MEK/ERK also resulted in down-regulation of GRP78, which was physically associated with caspase-4, before and after treatment with tunicamycin or thapsigargin. In addition, siRNA knockdown of GRP78 increased ER stress-induced caspase-4 activation and apoptosis. Taken together, these results seem to have important implications for new treatment strategies in melanoma by combinations of agents that induce ER stress and inhibitors of the MEK/ERK pathway.
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Apoptose/fisiologia , Retículo Endoplasmático/fisiologia , MAP Quinase Quinase Quinases/antagonistas & inibidores , Melanoma/enzimologia , Butadienos/farmacologia , Inibidores de Caspase , Caspases/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Chaperona BiP do Retículo Endoplasmático , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Proteínas de Choque Térmico/antagonistas & inibidores , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Melanoma/patologia , Chaperonas Moleculares/antagonistas & inibidores , Chaperonas Moleculares/biossíntese , Chaperonas Moleculares/metabolismo , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Interferente Pequeno/genética , Tapsigargina/farmacologia , Transfecção , Tunicamicina/farmacologiaRESUMO
We have reported previously low expression of death receptors for tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in fresh isolates and tissue sections of melanoma. This seemed to correlate with relative resistance of freshly isolated melanoma cells to TRAIL-induced apoptosis. We show in this study that the endoplasmic reticulum (ER) stress inducer, tunicamycin, selectively up-regulated the cell surface expression of TRAIL-R2, but not other members of the TNF receptor family, and enhanced TRAIL-induced apoptosis in cultured melanoma cells and fresh melanoma isolates. Tunicamycin-mediated sensitization of melanoma cells to TRAIL-induced apoptosis was associated with increased activation of the caspase cascade and reduction in mitochondrial membrane potential and was inhibited by a recombinant TRAIL-R2/Fc chimeric protein. Up-regulation of TRAIL-R2 on the melanoma cell surface was associated with increased transcription of TRAIL-R2 and its total protein levels. Two signaling pathways of the ER stress-induced unfolded protein response mediated by inositol-requiring transmembrane kinase and endonuclease 1alpha (IRE1alpha) and activation of transcription factor 6 (ATF6), respectively, seemed to be involved. In one melanoma line, there was clear evidence of activation of the IRE1alpha pathway, and small interfering RNA (siRNA) knockdown of IRE1alpha substantially reduced the up-regulation of TRAIL-R2. Similarly, there was evidence for the activation of the ATF6 pathway, and siRNA knockdown of ATF6 had a delayed effect on TRAIL-R2 expression in one but not another melanoma cell line. Moreover, the transcription factor CCAAT/enhancer-binding protein homologous protein seemed to be involved in the up-regulation of TRAIL-R2 by tunicamycin, but its role varied between different melanoma lines. Taken together, our results suggest that agents that induce ER stress may enhance TRAIL-R2 expression and increase the therapeutic response to TRAIL in melanoma.
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Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Melanoma/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Tunicamicina/farmacologia , Fator 6 Ativador da Transcrição/efeitos dos fármacos , Fator 6 Ativador da Transcrição/metabolismo , Apoptose/fisiologia , Western Blotting , Linhagem Celular Tumoral , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Confocal , Membranas Mitocondriais/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Regulação para CimaRESUMO
PURPOSE: To evaluate the impact of targeted DNA sequencing on selection of cancer therapy for patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: In this prospective, single-center, single-arm trial, patients with MBC were enrolled within 10 weeks of starting a new therapy. At enrollment, tumor samples underwent next-generation sequencing for any of 315 cancer-related genes to high depth (> 500×) using FoundationOne CDx. Sequencing results were released to providers at the time of disease progression, and physician treatment recommendations were assessed via questionnaire. We evaluated three prespecified questions to assess patients' perceptions of genomic testing. RESULTS: In all, 100 patients underwent genomic testing, with a median of five mutations (range, 0 to 13 mutations) detected per patient. Genomic testing revealed one or more potential therapies in 98% of patients (98 of 100), and 60% of patients (60 of 100) had one or more recommended treatments with level I/II evidence for actionability. Among the 94 genomic text reports that were released, there was physician questionnaire data for 87 patients (response rate, 92.6%) and 31.0% of patients (27 of 87) had treatment change recommended by their physician. Of these, 37.0% (10 of 27) received the treatment supported by genomic testing. We did not detect a statistically significant difference in time-to-treatment failure (log-rank P = .87) or overall survival (P = .71) among patients who had treatment change supported by genomic testing versus those who had no treatment change. For patients who completed surveys before and after genomic testing, there was a significant decrease in confidence of treatment success, specifically among patients who did not have treatment change supported by genomic testing (McNemar's test of agreement P = .001). CONCLUSION: In this prospective study, genomic profiling of tumors in patients with MBC frequently identified potential treatments and resulted in treatment change in a minority of patients. Patients whose therapy was not changed on the basis of genomic testing seemed to have a decrease in confidence of treatment success.
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PURPOSE: Given that inhibitors of mitogen-activated protein (MAP)/extracellular signal-regulated kinase (ERK) kinase (MEK) are being introduced into treatment for melanoma, the present study was carried out to better understand the mechanism by which they may induce apoptosis of melanoma cells. EXPERIMENTAL DESIGN: A panel of human melanoma cell lines and fresh melanoma isolates was assessed for their sensitivity to apoptosis induced by the MEK inhibitor U0126. The apoptotic pathways and regulatory mechanisms involved were examined by use of the inhibitor and small interfering RNA (siRNA) techniques. RESULTS: Inhibition of MEK induced apoptosis in the majority of melanoma cell lines through a mitochondrial pathway that was associated with the activation of Bax and Bak, release of mitochondrial apoptogenic proteins, and activation of caspase-3. However, apoptosis was independent of caspases and instead was associated with mitochondrial release of AIF as shown by the inhibition of apoptosis when AIF was knocked down by siRNA. Inhibition of MEK resulted in the up-regulation of the BH3-only proteins PUMA and Bim and down-regulation of the antiapoptotic protein Mcl-1. These changes were critical for the induction of apoptosis by U0126 as siRNA knockdown of PUMA or Bim inhibited apoptosis, whereas siRNA knockdown of Mcl-1 increased apoptosis particularly in the apoptosis-resistant cell lines. CONCLUSIONS: Apoptosis of melanoma cells induced by the inhibition of the MEK/ERK pathway is mediated by the up-regulation/activation of PUMA and Bim and down-regulation of Mcl-1. Release of AIF rather than the activation of caspases seems to be the mediator of apoptosis. Our results suggest that cotargeting Mcl-1 and the MEK/ERK pathway may further improve treatment results in melanoma.
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Proteínas Reguladoras de Apoptose/fisiologia , Apoptose/efeitos dos fármacos , Caspases/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Melanoma/tratamento farmacológico , Proteínas de Membrana/fisiologia , Proteínas de Neoplasias/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular Tumoral , Humanos , Melanoma/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Mutação , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas Proto-Oncogênicas B-raf/genética , Proteína Killer-Antagonista Homóloga a bcl-2/fisiologia , Proteína X Associada a bcl-2/fisiologia , Proteína de Morte Celular Associada a bcl/fisiologiaRESUMO
PURPOSE: Heterogeneous sensitivity of melanoma cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis may lead to outgrowth of TRAIL-resistant cells and limit successful treatment by TRAIL. The present study aims to better understand the biological characteristics of melanoma cells resistant to TRAIL-induced apoptosis. EXPERIMENTAL DESIGN: We generated TRAIL-resistant melanoma cells by prolonged exposure to TRAIL and characterized the cells in terms of their sensitivity to killing induced by a panel of cytotoxic agents using biological and biochemical methods. RESULTS: TRAIL-resistant melanoma cells are cross-resistant to apoptosis induced by another death ligand FasL, the DNA-damaging agent cisplatin, the histone deacetylase inhibitor suberic bishydroxamate, and the antimicrotubule Vinca alkaloid, vincristine. The apoptotic signaling seemed to be inhibited upstream of mitochondrial apoptotic events and was associated with decreased expression of multiple apoptotic mediators, including pro-caspase-8, Fas-associated death domain, Bid, Bim, p53, and the products of its proapoptotic target genes. Despite being resistant to apoptosis, TRAIL-resistant melanoma cells were more vulnerable to cisplatin-induced nonapoptotic cell death. This was characterized by lack of DNA fragmentation, delayed externalization of phosphatidylserine, caspase and p53 independence, and severe mitochondrial disruption, and was preceded by poly(ADP)ribose polymerase (PARP) activation and depletion of intracellular ATP, indicative of necrotic cell death. Inhibition of PARP activity partially converted the mode of cell death from necrosis to apoptosis. CONCLUSIONS: TRAIL-resistant melanoma cells are cross-resistant to apoptosis induced by various apoptotic stimuli but are more sensitive to nonapoptotic cell death induced by cisplatin. Exploration of chemotherapy-induced nonapoptotic cell death may provide an alternative strategy in overcoming resistance of melanoma cells to TRAIL-induced apoptosis.
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Proteínas Reguladoras de Apoptose/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Glicoproteínas de Membrana/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Western Blotting , Caspase 3 , Caspases/metabolismo , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Proteína Ligante Fas , Citometria de Fluxo , Inibidores de Histona Desacetilases , Humanos , Ácidos Hidroxâmicos/farmacologia , Melanoma/metabolismo , Melanoma/patologia , Potenciais da Membrana/efeitos dos fármacos , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/fisiologia , Necrose/induzido quimicamente , Poli(ADP-Ribose) Polimerases , Propídio/farmacocinética , Ligante Indutor de Apoptose Relacionado a TNF , Fatores de Tempo , Fatores de Necrose Tumoral/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Vincristina/farmacologiaAssuntos
Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Alimentos Infantis/efeitos adversos , Alimentos Infantis/virologia , Mastigação , Adulto , Cuidadores , Países Desenvolvidos , Microbiologia de Alimentos , Gengivite/complicações , Infecções por HIV/complicações , Hemorragia/complicações , Humanos , Lactente , Saliva/virologia , Erupção Dentária , Precauções UniversaisRESUMO
Protein kinase C (PKC) activation is believed to protect against apoptosis induced by death receptors. We have found however that the effect of activation of PKC on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis of melanoma differs between cell lines. Pretreatment with phorbol 12-myristate 13-acetate (PMA) led to inhibition of apoptosis in the majority of the melanoma cell lines, but those with relatively low PKC epsilon expression were sensitized to TRAIL-induced apoptosis. Introduction of PKC epsilon into PKC epsilon-low cell lines reversed sensitization of the cells to TRAIL-induced apoptosis by PMA. In contrast, a dominant-negative form of PKC epsilon caused an increase in sensitivity. The changes in sensitivity to TRAIL-induced apoptosis were reflected in similar changes in conformation of Bax and its relocation from the cytosol to mitochondria. Similarly, there were concordant increases or decreases in mitochondrial release of second mitochondria-derived activator of caspase/DIABLO, activation of caspase-3, and processing of its substrates. Activation of PKC seemed to mediate its effects upstream of mitochondria but downstream of caspase-8 and Bid in that pretreatment with PMA did not cause significant changes in the expression levels of TRAIL death receptors, alterations in the levels of caspase-8 activation, or cleavage of Bid. PKC activated the anti-apoptotic extracellular signal-regulated kinase 1/2 pathway, but inhibitors of this pathway only partially reversed the protective effect of PKC against TRAIL-induced apoptosis. These results provide further insights into the variable responses of melanoma to TRAIL-induced apoptosis and may help define responsive phenotypes to treatment of melanoma with TRAIL.
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Apoptose , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Melanoma/enzimologia , Melanoma/patologia , Glicoproteínas de Membrana/metabolismo , Proteína Quinase C/biossíntese , Fator de Necrose Tumoral alfa/metabolismo , Adenoviridae/genética , Proteínas Reguladoras de Apoptose , Western Blotting , Caspase 3 , Caspase 8 , Caspases/metabolismo , Linhagem Celular Tumoral , Citosol/metabolismo , Citometria de Fluxo , Vetores Genéticos , Humanos , Melanoma/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Fenótipo , Plasmídeos/metabolismo , Conformação Proteica , Proteína Quinase C-épsilon , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Recombinantes/química , Ligante Indutor de Apoptose Relacionado a TNF , Acetato de Tetradecanoilforbol/farmacologia , Transfecção , Proteína X Associada a bcl-2RESUMO
To better understand the outcome of the interaction between TNF-related apoptosis-inducing factor (TRAIL) and tumor cells, we studied TRAIL-resistant melanoma cells resulting from prolonged exposure to TRAIL and found that they had higher proliferative activity than the parental cells both in vitro and in vivo. This was associated with reduced p53 and p21 expression and increased activation of Erk1/2 and Akt. Accelerated proliferation was not due to TRAIL-mediated signaling but appeared to be the result of selection of previously existing, characteristically distinct cells. Moreover, responses of p53 to stimulation in the TRAIL-resistant cells appeared to be impaired.
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Antineoplásicos/farmacologia , Melanoma/metabolismo , Glicoproteínas de Membrana/farmacologia , Neoplasias Cutâneas/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Apoptose , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ligante Indutor de Apoptose Relacionado a TNF , Proteína Supressora de Tumor p53/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoAssuntos
Contaminação de Equipamentos/prevenção & controle , Equipamentos e Provisões/normas , Serviço Hospitalar de Engenharia e Manutenção/métodos , Serviço Hospitalar de Engenharia e Manutenção/normas , Esterilização/normas , Instrumentos Cirúrgicos/normas , Cirurgia Geral/instrumentação , Cirurgia Geral/métodos , Guias como Assunto , Humanos , Política Organizacional , Esterilização/instrumentação , Esterilização/métodos , Fatores de TempoRESUMO
Staurosporine has long been used in vitro as an initiator of apoptosis in many different cell types, but the mechanism involved remains poorly understood. In the present study, we have examined the apoptosis-inducing potential of staurosporine in cultured melanoma cell lines and dissected the staurosporine-induced apoptotic signaling pathway. We report that although staurosporine activated Bax and the mitochondrial caspase-dependent apoptotic pathway, it also induced apoptosis of melanoma by caspase-independent pathways. The caspase-dependent apoptotic pathway was activated relatively soon after exposure to staurosporine and was associated with release of cytochrome c and Smac/DIABLO from mitochondria and cleavage of poly(ADP-ribose) polymerase and inhibitor of caspase-activated DNase. This pathway was inhibitable by broad caspase inhibitors. A second apoptotic pathway that appeared to be involved in late apoptotic events was caspase independent in that inhibitors of caspases did not prevent the late onset of apoptosis. Overexpression of Bcl-2 inhibited the early onset of apoptosis but not the later, caspase-independent pathway. Apoptosis-inducing factor may be responsible for the late apoptotic execution in that its translocation from mitochondria into the nucleus coincided with the late onset of apoptosis and could not be inhibited by either a pan-caspase inhibitor or overexpression of Bcl-2. Our results indicate that staurosporine is able to bypass resistance of melanoma cells to mitochondrial caspase-dependent apoptotic pathways; hence, derivatives of staurosporine may warrant further evaluation either alone or with other apoptosis-inducing agents.
Assuntos
Apoptose/efeitos dos fármacos , Caspases/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Estaurosporina/farmacologia , Fator de Indução de Apoptose , Proteínas Reguladoras de Apoptose , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Citosol/metabolismo , Ativação Enzimática/efeitos dos fármacos , Flavoproteínas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Melanoma/enzimologia , Potenciais da Membrana/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Proteínas Mitocondriais/metabolismo , Conformação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteína X Associada a bcl-2RESUMO
Ingenol 3-angelate (PEP005), one of the active ingredients in an extract from Euphorbia peplus, was shown in preclinical studies to have activity against human melanoma xenografts in nude mice. In the present study, we have tested its ability to induce the apoptosis of melanoma cells in vitro in the absence or presence of tumor necrosis factor-related apoptosis inducing ligand (TRAIL). The results showed that at relatively high concentrations (100 microg/mL), PEP005 killed melanoma cells mainly by induction of necrosis. In 20% of cell lines, evidence of apoptosis was observed. Apoptosis was caspase-dependent and associated with changes in mitochondrial membrane potential that were not inhibitable by overexpression of Bcl-2 or inhibition of caspases but were blocked by inhibition of protein kinase C (PKC). Low concentrations (1 or 10 microg/mL) of PEP005 either increased or decreased TRAIL-induced apoptosis in a cell line-dependent manner. These changes in TRAIL-induced apoptosis seemed to be due to activation of PKC and varying levels of PKC isoenzymes in different melanoma cell lines. PEP005-mediated enhancement of apoptosis seemed to be associated with low expression of the PKCepsilon isoform. These results indicate that PEP005 may enhance or inhibit sensitivity of melanoma to treatments associated with TRAIL-induced apoptosis depending on the PKC isoform content of melanoma cells.
Assuntos
Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Ésteres/farmacologia , Melanoma/metabolismo , Melanoma/patologia , Glicoproteínas de Membrana/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Reguladoras de Apoptose , Caspases/metabolismo , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/imunologia , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Proteína Quinase C-épsilon , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Cutâneas/imunologia , Ligante Indutor de Apoptose Relacionado a TNF , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Histone deacetylase (HDAC) inhibitors have attracted much interest because of their ability to arrest cell growth, induce cell differentiation, and in some cases, induce apoptosis of cancer cells. In the present study, we have examined a new HDAC inhibitor, suberic bishydroxamate (SBHA), for its effect on a panel of human melanoma cell lines. We report that it induces varying degrees of apoptosis in the melanoma lines but not in melanocytes and fibroblasts. Induction of apoptosis was caspase dependent and was associated with induction of changes in mitochondrial membrane permeability, which could be inhibited by overexpression of Bcl-2. The changes in mitochondria were independent of caspase activation and were associated with changes in conformation of Bax. SBHA down-regulated several key antiapoptotic proteins including X-linked inhibitor of apoptosis and the Bcl-2 family proteins, Bcl-XL and Mcl-1. In contrast, it induced up-regulation of the Bcl-2 family proapoptotic proteins, Bim, Bax, and Bak. In addition, SBHA induced relocation of the protein Bim to mitochondria and its association with Bcl-2. De novo protein synthesis was required for initiation of apoptosis in that the protein synthesis inhibitor, cycloheximide, inhibited SBHA-induced conformational changes in Bax as well as changes in mitochondrial membrane permeability and activation of caspase-3. These results suggest that SBHA induces apoptosis by changing the balance between proapoptotic and antiapoptotic proteins in melanoma cells. The protein Bim may be a key initiator of apoptosis in cells treated with SBHA.
Assuntos
Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Ácidos Hidroxâmicos/farmacologia , Melanoma/patologia , Mitocôndrias/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Proteínas Reguladoras de Apoptose , Proteína 11 Semelhante a Bcl-2 , Proteínas de Transporte/metabolismo , Caspase 3 , Inibidores de Caspase , Caspases/metabolismo , Linhagem Celular Tumoral , Inibidores de Cisteína Proteinase/farmacologia , Histona Desacetilases/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/efeitos dos fármacos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas de Neoplasias/metabolismo , Oligopeptídeos/farmacologia , Permeabilidade/efeitos dos fármacos , Conformação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2 , Proteína bcl-XRESUMO
BACKGROUND AND OBJECTIVE: Although nonphysician reentry transitions have been characterized in literature, little is known about the reentry physicians in general, or residents in particular. We conducted a qualitative study to explore pediatric residents' reentry, using reverse culture shock as a conceptual framework. METHODS: Eighteen pediatric residents who completed global health experiences in Africa (9 categorical residents with 1-month elective, 9 global child health residents with 12-month training) participated in interviews that included a card-sort to solicit emotional responses consistent with the conceptual framework. Data in the form of interview transcripts were coded and analyzed according to principles of grounded theory. RESULTS: All pediatric residents, despite variable time abroad, reported a range of emotional responses on reentry to residency. Global child health residents felt disconnection and frustration more intensely than categorical residents, whereas categorical residents felt invigoration more intensely than global child health residents. Although residents met with program leadership after their return, no resident described these meetings as a formal debriefing, and few described a deliberate strategy for processing emotions on reentry. CONCLUSIONS: Consistent with reverse culture shock, pediatric residents felt a range of emotions as they move toward a steady state of acculturating back into their residency program. Residency programs might consider creating safety nets to help cultivate support for residents when they reenter training.