Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Qual Life Res ; 32(4): 1199-1208, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36495384

RESUMO

INTRODUCTION: EQ-5D-3L preference-based value sets are predominately based on hypothetical health states and derived in cross-sectional settings. Therefore, we derived an experience-based value set from a prospective observational study. METHODS: The International Costs and Utilities Related to Osteoporotic fractures Study (ICUROS) was a multinational study on fragility fractures, prospectively collecting EQ-5D-3L and Time trade-off (TTO) within two weeks after fracture (including pre-fracture recall), and at 4, 12, and 18 months thereafter. We derived an EQ-5D-3L value set by regressing the TTO values on the ten impairment levels in the EQ-5D-3L. We explored the potential for response shift and whether preferences for domains vary systematically with prior impairment in that domain. Finally, we compared the value set to 25 other EQ-5D-3L preference-based value sets. RESULTS: TTO data were available for 12,954 EQ-5D-3L health states in 4683 patients. All coefficients in the value set had the expected sign, were statistically significant, and increased monotonically with severity of impairment. We found evidence for response shift in mobility, self-care, and usual activities. The value set had good agreement with the only other experience- and preference-based value set, but poor agreement with all hypothetical value sets. CONCLUSIONS: We present an experience- and preference-based value set with high face validity. The study indicates that response shift may be important to account for when deriving value sets. Furthermore, the study suggests that perspective (experienced versus hypothetical) is more important than country setting or demographics for valuation of EQ-5D-3L health states.


Assuntos
Nível de Saúde , Fraturas por Osteoporose , Humanos , Qualidade de Vida/psicologia , Estudos Transversais , Inquéritos e Questionários
2.
Qual Life Res ; 27(3): 707-716, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29235059

RESUMO

INTRODUCTION: The International Costs and Utilities Related to Osteoporotic fractures Study is a multinational observational study set up to describe the costs and quality of life (QoL) consequences of fragility fracture. This paper aims to estimate and compare QoL after hip, vertebral, and distal forearm fracture using time-trade-off (TTO), the EuroQol (EQ) Visual Analogue Scale (EQ-VAS), and the EQ-5D-3L valued using the hypothetical UK value set. METHODS: Data were collected at four time-points for five QoL point estimates: within 2 weeks after fracture (including pre-fracture recall), and at 4, 12, and 18 months after fracture. Health state utility values (HSUVs) were derived for each fracture type and time-point using the three approaches (TTO, EQ-VAS, EQ-5D-3L). HSUV were used to estimate accumulated QoL loss and QoL multipliers. RESULTS: In total, 1410 patients (505 with hip, 316 with vertebral, and 589 with distal forearm fracture) were eligible for analysis. Across all time-points for the three fracture types, TTO provided the highest HSUVs, whereas EQ-5D-3L consistently provided the lowest HSUVs directly after fracture. Except for 13-18 months after distal forearm fracture, EQ-5D-3L generated lower QoL multipliers than the other two methods, whereas no equally clear pattern was observed between EQ-VAS and TTO. On average, the most marked differences between the three approaches were observed immediately after the fracture. CONCLUSIONS: The approach to derive QoL markedly influences the estimated QoL impact of fracture. Therefore the choice of approach may be important for the outcome and interpretation of cost-effectiveness analysis of fracture prevention.


Assuntos
Antebraço/patologia , Fraturas Ósseas/psicologia , Quadril/patologia , Medição da Dor/métodos , Qualidade de Vida/psicologia , Coluna Vertebral/patologia , Idoso , Feminino , Fraturas Ósseas/economia , Fraturas Ósseas/patologia , Nível de Saúde , Humanos , Masculino , Inquéritos e Questionários
3.
Int J Gynecol Cancer ; 23(5): 823-32, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23666016

RESUMO

OBJECTIVE: Despite the considerable disease burden of ovarian cancer, there were no cost studies in Central and Eastern Europe. This study aimed to describe treatment patterns, health care utilization, and costs associated with treating ovarian cancer in Hungary, Poland, Serbia, and Slovakia. METHOD: Overall clinical practice for management of epithelial ovarian cancer was investigated through a 3-round Delphi panel. Experts completed a survey based on the chart review (n = 1542). The survey was developed based on clinical guidelines and the International Federation of Gynecology and Obstetrics Annual Report. Means, ranges, and outlier values were discussed with the experts during a telephone interview. Finally, consensus estimates were obtained in face-to-face workshops. Based on these results, overall cost of ovarian cancer was estimated using a Markov model. RESULTS: The patients included in the chart review were followed up from presurgical diagnosis and in each phase of treatment, that is, surgical staging and primary surgery, chemotherapy and chemotherapy monitoring, follow-up, and palliative care. The 5-year overall cost per patient was €14,100 to €16,300 in Hungary, €14,600 to €15,800 in Poland, €7600 to €8100 in Serbia, and €12,400 to €14,500 in Slovakia. The main components were chemotherapy-associated costs (68%-74% of the total cost), followed by cost of primary treatment with surgery (15%-21%) and palliative care (3%-10%). CONCLUSIONS: Patients with ovarian cancer consume considerable health care resources and incur substantial costs in Central and Eastern Europe. These findings may prove useful for clinicians and decision makers in understanding the economic implications of managing ovarian cancer in Central and Eastern Europe and the need for innovative therapies.


Assuntos
Custos de Cuidados de Saúde , Serviços de Saúde/estatística & dados numéricos , Neoplasias Ovarianas/economia , Cuidados Paliativos , Terapia Combinada , Análise Custo-Benefício , Feminino , Seguimentos , Humanos , Hungria , Cadeias de Markov , Neoplasias Ovarianas/terapia , Polônia , Prognóstico , Estudos Retrospectivos , Sérvia , Eslováquia , Centros de Atenção Terciária
4.
Adv Ther ; 40(10): 4657-4674, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37599341

RESUMO

INTRODUCTION: Treatment persistence is a proxy for efficacy, safety and patient satisfaction, and a switch in treatment or treatment discontinuation has been associated with increased indirect and direct costs in inflammatory arthritis (IA). Hence, there are both clinical and economic incentives for the identification of factors associated with treatment persistence. Until now, studies have mainly leveraged traditional regression analysis, but it has been suggested that novel approaches, such as statistical learning techniques, may improve our understanding of factors related to treatment persistence. Therefore, we set up a study using nationwide Swedish high-coverage administrative register data with the objective to identify patient groups with distinct persistence of subcutaneous tumor necrosis factor inhibitor (SC-TNFi) treatment in IA, using recursive partitioning, a statistical learning algorithm. METHODS: IA was defined as a diagnosis of rheumatic arthritis (RA), ankylosing spondylitis/unspecified spondyloarthritis (AS/uSpA) or psoriatic arthritis (PsA). Adult swedish biologic-naïve patients with IA initiating biologic treatment with a SC-TNFi (adalimumab, etanercept, certolizumab or golimumab) between May 6, 2010, and December 31, 2017. Treatment persistence of SC-TNFi was derived based on prescription data and a defined standard daily dose. Patient characteristics, including age, sex, number of health care contacts, comorbidities and treatment, were collected at treatment initiation and 12 months before treatment initiation. Based on these characteristics, we used recursive partitioning in a conditional inference framework to identify patient groups with distinct SC-TNFi treatment persistence by IA diagnosis. RESULTS: A total of 13,913 patients were included. Approximately 50% had RA, while 27% and 23% had AS/uSpA and PsA, respectively. The recursive partitioning algorithm identified sex and treatment as factors associated with SC-TNFi treatment persistence in PsA and AS/uSpA. Time on treatment in the groups with the lowest treatment persistence was similar across all three indications (9.5-11.3 months), whereas there was more variation in time on treatment across the groups with the highest treatment persistence (18.4-48.9 months). CONCLUSIONS: Women have low SC-TNFi treatment persistence in PsA and AS/uSpA whereas male sex and golimumab are associated with high treatment persistence in these indications. The factors associated with treatment persistence in RA were less distinct but may comprise disease activity and concurrent conventional systemic disease-modifying anti-rheumatic drug (DMARD) treatment.


Assuntos
Antirreumáticos , Artrite Psoriásica , Artrite Reumatoide , Produtos Biológicos , Espondilartrite , Espondilite Anquilosante , Adulto , Humanos , Feminino , Lactente , Inibidores do Fator de Necrose Tumoral/uso terapêutico , Artrite Psoriásica/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Espondilite Anquilosante/tratamento farmacológico , Antirreumáticos/uso terapêutico , Árvores de Decisões , Produtos Biológicos/uso terapêutico
5.
MDM Policy Pract ; 7(1): 23814683221089659, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35356551

RESUMO

Background: Survival heterogeneity and limited trial follow-up present challenges for estimating lifetime benefits of oncology therapies. This study used CheckMate 067 (NCT01844505) extended follow-up data to assess the predictive accuracy of standard parametric and flexible models in estimating the long-term overall survival benefit of nivolumab plus ipilimumab (an immune checkpoint inhibitor combination) in advanced melanoma. Methods: Six sets of survival models (standard parametric, piecewise, cubic spline, mixture cure, parametric mixture, and landmark response models) were independently fitted to overall survival data for treatments in CheckMate 067 (nivolumab plus ipilimumab, nivolumab, and ipilimumab) using successive data cuts (28, 40, 52, and 60 mo). Standard parametric models allow survival extrapolation in the absence of a complex hazard. Piecewise and cubic spline models allow additional flexibility in fitting the hazard function. Mixture cure, parametric mixture, and landmark response models provide flexibility by explicitly incorporating survival heterogeneity. Sixty-month follow-up data, external ipilimumab data, and clinical expert opinion were used to evaluate model estimation accuracy. Lifetime survival projections were compared using a 5% discount rate. Results: Standard parametric, piecewise, and cubic spline models underestimated overall survival at 60 mo for the 28-mo data cut. Compared with other models, mixture cure, parametric mixture, and landmark response models provided more accurate long-term overall survival estimates versus external data, higher mean survival benefit over 20 y for the 28-mo data cut, and more consistent 20-y mean overall survival estimates across data cuts. Conclusion: This case study demonstrates that survival models explicitly incorporating survival heterogeneity showed greater accuracy for early data cuts than standard parametric models did, consistent with similar immune checkpoint inhibitor survival validation studies in advanced melanoma. Research is required to assess generalizability to other tumors and disease stages. Highlights: Given that short clinical trial follow-up periods and survival heterogeneity introduce uncertainty in the health technology assessment of oncology therapies, this study evaluated the suitability of conventional parametric survival modeling approaches as compared with more flexible models in the context of immune checkpoint inhibitors that have the potential to provide lasting survival benefits.This study used extended follow-up data from the phase III CheckMate 067 trial (NCT01844505) to assess the predictive accuracy of standard parametric models in comparison with more flexible methods for estimating the long-term survival benefit of the immune checkpoint inhibitor combination of nivolumab plus ipilimumab in advanced melanoma.Mixture cure, parametric mixture, and landmark response models provided more accurate estimates of long-term overall survival versus external data than other models tested.In this case study with immune checkpoint inhibitor therapies in advanced melanoma, extrapolation models that explicitly incorporate differences in cancer survival between observed or latent subgroups showed greater accuracy with both early and later data cuts than other approaches did.

6.
EJHaem ; 2(3): 385-393, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35844713

RESUMO

Acute myeloid leukemia (AML) is associated with a high economic and clinical burden. Recently novel therapies have been added to standard treatment regimens. Here, we evaluated the economic impact of AML up until the introduction of these novel therapies. Individual data on 2954 adult patients diagnosed from 2007 to 2015 from five Swedish national population-based registers were used, enabling analyses from diagnosis to either death or 5-year follow-up for survival, inpatient and outpatient costs, costs of prescribed drugs, sick leave, and early retirement. Costs per patient were stratified by age group, treatment options, and FLT3-ITD status. The expected 5-year costs per patient differed substantially between age groups. Patients aged 18-59 years had an expected mean cost per patient of €170,748, while age groups 60-69 years, 70-79 years, and >80 years incurred an expected mean cost of €92,252, €48,344, and €24,118, respectively, over 5 years. Patients <60 years undergoing stem cell transplantation had the highest costs (€228,525 over 5 years). About 60% of costs for these patients were from hospitalizations and 20% from sick leave and early retirement; cost per day was highest from the first admission to complete remission. This study provides a baseline for socioeconomic evaluations of novel therapies in AML in Sweden.

7.
Int J Cancer ; 123(2): 476-483, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18452174

RESUMO

Inhibition of energy production as a strategy for potentiation of anticancer chemotherapy was investigated using 1 glycolysis inhibitor and 1 fatty acid beta-oxidation inhibitor-2-deoxyglucose and etomoxir, respectively, both known to be clinically well tolerated. Eighteen anticancer drugs were screened for potentiation by these inhibitors. 2-deoxyglucose potentiated acute apoptosis (24 hr) induced mainly by some, but not all, genotoxic drugs, whereas etomoxir had effect only on cisplatin. By contrast, etomoxir did potentiate the overall, 48 hr effects of some genotoxic drugs, and was in addition more efficient than deoxyglucose in potentiating the overall effects of several non-genotoxic drugs. Both types of potentiation were largely lost in the absence of p53. Because cisplatin was potentiated by both energy inhibitors in both types of assay, it was investigated at additional concentrations and over longer time. Both energy inhibitors strongly potentiated non-apoptotic concentrations of cisplatin in p53-wildtype as well as in p53-deficient, cisplatin-resistant HCT-116 colon carcinoma cells. Reduced ATP levels correlated with, but were not sole determinants, the antiproliferative effects. We conclude that the long-term effects of cisplatin potentiation are important and either p53-independent or improved by a lack of p53. We also conclude that although the potentiated drugs as yet have no obvious mechanistic factor in common, the strategy holds promise with genotoxic as well non-genotoxic anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Neoplasias do Colo/tratamento farmacológico , Desoxiglucose/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Metabolismo Energético/efeitos dos fármacos , Compostos de Epóxi/farmacologia , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Sinergismo Farmacológico , Células HCT116 , Humanos , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
8.
Nat Commun ; 5: 3295, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24548894

RESUMO

Abnormal vascularization of solid tumours results in the development of microenvironments deprived of oxygen and nutrients that harbour slowly growing and metabolically stressed cells. Such cells display enhanced resistance to standard chemotherapeutic agents and repopulate tumours after therapy. Here we identify the small molecule VLX600 as a drug that is preferentially active against quiescent cells in colon cancer 3-D microtissues. The anticancer activity is associated with reduced mitochondrial respiration, leading to bioenergetic catastrophe and tumour cell death. VLX600 shows enhanced cytotoxic activity under conditions of nutrient starvation. Importantly, VLX600 displays tumour growth inhibition in vivo. Our findings suggest that tumour cells in metabolically compromised microenvironments have a limited ability to respond to decreased mitochondrial function, and suggest a strategy for targeting the quiescent populations of tumour cells for improved cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Hidrazonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Triazóis/farmacologia , Microambiente Tumoral , Animais , Autofagia/efeitos dos fármacos , Feminino , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Hipóxia/induzido quimicamente , Camundongos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Esferoides Celulares , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Eur J Cancer ; 48(3): 396-406, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22154651

RESUMO

PURPOSE: Regrowth of tumour cells between cycles of chemotherapy is a significant clinical problem. Treatment strategies where antiproliferative agents are used to inhibit tumour regrowth between chemotherapy cycles are attractive, but such strategies are difficult to test using conventional monolayer culture systems. METHODS: We used the in vitro tumour spheroid model to study regrowth of 3-D colon carcinoma tissue after cytotoxic therapy. Colon carcinoma cells with wild-type or mutant phosphatidyl inositol 3-kinase catalytic subunit (PI3KCA) or KRAS alleles were allowed to form multicellular spheroids and the effects of different pharmacological compounds were studied after sectioning and staining for relevant markers of cell proliferation and apoptosis. RESULTS: Studies using colon cancer cells with gene disruptions suggested that the phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) pathway was essential for proliferation in 3-D culture. The dual PI3K-mTOR inhibitor NVP-BEZ235, currently in clinical trials, was found to inhibit phosphorylation of the mTOR target 4EBP1 in 3-D cultured cells. The ability of NVP-BEZ235 to inhibit tumour cell proliferation and to induce apoptosis was markedly more pronounced in 3-D cultures compared to monolayer cultures. It was subsequently found that NVP-BEZ235 was effective in inhibiting regrowth of 3-D cultured cells after treatment with two cytotoxic inhibitors of the ubiquitin-proteasome system (UPS), methyl-13-hydroxy-15-oxokaurenoate (MHOK) and bortezomib (Velcade®). CONCLUSIONS: The dual PI3K-mTOR inhibitor NVP-BEZ235 was found to reduce cell proliferation and to induce apoptosis in 3-D cultured colon carcinoma cells, NVP-BEZ235 is a promising candidate for use in sequential treatment modalities together with cytotoxic drugs to reduce the cell mass of solid tumours.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Neoplasias do Colo/tratamento farmacológico , Imidazóis/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Quinolinas/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Células Tumorais Cultivadas
10.
Free Radic Biol Med ; 46(12): 1607-13, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19328230

RESUMO

The cellular response to DNA damage has been reported to involve rapid transcription-independent translocation of p53 to mitochondria. We show here that the DNA-damaging cisplatin-derived anticancer agent oxaliplatin induced both mitochondrial translocation and subsequent Bcl-xL interaction, whereas cisplatin did neither. The differential response was due to nitrosative modification of p53. Thus, cisplatin, but not oxaliplatin, induced increased expression of inducible nitric oxide synthase (iNOS). Cisplatin treatment in the presence of an iNOS inhibitor (1400W) allowed p53 mitochondrial translocation. Conversely, oxaliplatin-induced translocation of p53 was prevented by cotreatment with an exogenous NO donor. In cisplatin-treated cells, nuclear but not mitochondrial p53 showed nitrotyrosinylation that was inhibitable by 1400W. We conclude that nitrosative protein modification is more prominent in the response to cisplatin than oxaliplatin and that nitrosative modification of p53 is a major determinant of p53 subcellular location.


Assuntos
Cisplatino/farmacologia , Mitocôndrias/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Amidinas/farmacologia , Benzilaminas/farmacologia , Humanos , Mitocôndrias/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Transporte Proteico/efeitos dos fármacos , Células Tumorais Cultivadas , Tirosina/análogos & derivados , Tirosina/metabolismo
11.
Mol Cancer Ther ; 8(7): 1916-23, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19567816

RESUMO

We have here examined chemopotentiating effects of glycolysis inhibitor 2-deoxy-d-glucose (DG) in two epithelial ovarian carcinoma (EOC) cell lines and 17 freshly isolated ascitic EOC cell samples, and we identify low expression of the beta-F1-ATPase involved in mitochondrial ATP production as a candidate marker for sensitivity to this strategy. Although in the majority of samples, DG per se did not induce apoptosis, cotreatment with DG potentiated apoptosis and total antiproliferative effects of cisplatin and, to a lesser degree, carboplatin. In the cell lines, combination treatment with DG and cisplatin or carboplatin at noninhibitory concentrations prevented posttreatment regrowth in drug-free medium over a total of 5 days. DG per se allowed complete recuperation in drug-free medium. The more platinum-resistant a cell line was, the more sensitive it was to potentiation by DG and showed higher glucose uptake, DG-sensitive lactate production, and lower beta-F1-ATPase levels. In the ascitic samples, DG reduced the median IC(50) for cisplatin by 68% and, in the most sensitive samples, up to 90%, and DG-mediated potentiation correlated with low expression of beta-F1-ATPase. By contrast, cisplatin sensitivity did not correlate with beta-F1-ATPase levels. The findings validate targeting cancer cell glucose metabolism for potentiating platinum chemotherapy in EOC and indicate that reduced beta-F1-ATPase/oxidative phosphorylation distinguishes cells that are amenable to this strategy.


Assuntos
Antineoplásicos/farmacologia , Carboplatina/farmacologia , Cisplatino/farmacologia , Desoxiglucose/farmacologia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Antimetabólitos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Humanos , Ácido Láctico/metabolismo , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/patologia , Células Tumorais Cultivadas
12.
J Chem Biol ; 2(2): 81-7, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19568785

RESUMO

The phosphatidylinositol 3-kinase (PI3K)/AKT pathway is frequently upregulated in human cancer. Activation of this pathway has been reported to be associated with resistance to various chemotherapeutical agents. We here used a chemical biology/chemical informatic approach to identify apoptotic mechanisms that are insensitive to activation of the PI3K/AKT pathway. The National Cancer Institute (NCI) Mechanistic Set drug library was screened for agents that induce apoptosis in colon carcinoma cells expressing a constitutively active form of AKT1. The cytotoxicity screening data available as self-organized maps at the Developmental Therapeutics Program (DTP) of the NCI was then used to classify the identified compounds according to mechanism of action. The results showed that drugs that interfere with the mitotic process induce apoptosis which is comparatively insensitive to constitutive AKT1 activity. The conditional screening approach described here is expected to be useful for identifying relationships between the state of activation of signaling pathways and sensitivity to anticancer agents.

13.
J Natl Cancer Inst ; 101(1): 37-47, 2009 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-19116379

RESUMO

BACKGROUND: Cisplatin is a cornerstone anticancer drug with pronounced ototoxicity, whereas oxaliplatin, a platinum derivative with a different clinical profile, is rarely ototoxic. This difference has not been explained. METHODS: In HCT-116 cells, cisplatin (20 microM)-induced apoptosis was reduced by a calcium chelator from 9.9-fold induction (95% confidence interval [CI] = 8.1- to 11.7-fold), to 3.1-fold induction (95% CI = 2.0- to 4.2-fold) and by superoxide scavenging from 9.3-fold (95% CI = 8.8- to 9.8-fold), to 5.1-fold (95% CI = 4.4- to 5.8-fold). A guinea pig model (n = 23) was used to examine pharmacokinetics. Drug concentrations were determined by liquid chromatography with post-column derivatization. The total platinum concentration in cochlear tissue was determined by inductively coupled plasma mass spectrometry. Drug pharmacokinetics was assessed by determining the area under the concentration-time curve (AUC). Statistical tests were two-sided. RESULTS: In HCT-116 cells, cisplatin (20 microM)-induced apoptosis was reduced by a calcium chelator from 9.9-fold induction (95% confidence interval [CI] = 8.1- to 11.7-fold to 3.1-fold induction) (95% CI = 2.0- to 4.2-fold) and by superoxide scavenging (from 9.3-fold, 95% CI = 8.8- to 9.8-fold, to 5.1-fold, 95% CI = 4.4- to 5.8-fold). Oxaliplatin (20 microM)-induced apoptosis was unaffected by calcium chelation (from 7.1- to 6.2-fold induction) and by superoxide scavenging (from 5.9- to 5.6-fold induction). In guinea pig cochlea, total platinum concentration (0.12 vs 0.63 microg/kg, respectively, P = .008) and perilymphatic drug concentrations (238 vs 515 microM x minute, respectively, P < .001) were lower after intravenous oxaliplatin treatment (16.6 mg/kg) than after equimolar cisplatin treatment (12.5 mg/kg). However, after a non-ototoxic cisplatin dose (5 mg/kg) or the same oxaliplatin dose (16.6 mg/kg), the AUC for perilymphatic concentrations was similar, indicating that the two drugs have different cochlear pharmacokinetics. CONCLUSION: Cisplatin- but not oxaliplatin-induced apoptosis involved superoxide-related pathways. Lower cochlear uptake of oxaliplatin than cisplatin appears to be a major explanation for its lower ototoxicity.


Assuntos
Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Carcinoma/tratamento farmacológico , Cisplatino/efeitos adversos , Cóclea/efeitos dos fármacos , Cóclea/metabolismo , Doenças Cocleares/induzido quimicamente , Neoplasias do Colo/tratamento farmacológico , Compostos Organoplatínicos/efeitos adversos , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Área Sob a Curva , Cálcio/metabolismo , Carcinoma/metabolismo , Carcinoma/patologia , Quelantes/farmacologia , Cromatografia Líquida , Cisplatino/administração & dosagem , Cisplatino/farmacocinética , Doenças Cocleares/metabolismo , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Intervalos de Confiança , Modelos Animais de Doenças , Feminino , Sequestradores de Radicais Livres/farmacologia , Cobaias , Células HCT116 , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/metabolismo , Humanos , Imuno-Histoquímica , Infusões Intravenosas , Masculino , Espectrometria de Massas/métodos , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/farmacocinética , Oxaliplatina , Oxidantes/metabolismo , Perilinfa/efeitos dos fármacos , Perilinfa/metabolismo , Rampa do Tímpano/efeitos dos fármacos , Rampa do Tímpano/metabolismo , Transdução de Sinais/efeitos dos fármacos , Superóxidos/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo
14.
Mol Oncol ; 2(1): 94-101, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19383331

RESUMO

Tumour cells depend on aerobic glycolysis for adenosine triphosphate (ATP) production, making energy metabolism an interesting therapeutic target. 3-Bromopyruvate (BP) has been shown by others to inhibit hexokinase and eradicate mouse hepatocarcinomas. We report that similar to the glycolysis inhibitor 2-deoxyglucose (DG), BP rapidly decreased cellular ATP within hours, but unlike DG, BP concomitantly induced mitochondrial depolarization without affecting levels of reducing equivalents. Over 24h, and at equitoxic doses, DG reduced glucose consumption more than did BP. The observed BP-induced loss of ATP is therefore largely due to mitochondrial effects. Cell death induced over 24h by BP, but not DG, was blocked by N-acetylcysteine, indicating involvement of reactive oxygen species. BP-induced cytotoxicity was independent of p53. When combined with cisplatin or oxaliplatin, BP led to massive cell death. The anti-proliferative effects of low-dose platinum were strikingly potentiated also in resistant p53-deficient cells. Together with the reported lack of toxicity, this indicates the potential of BP as a clinical chemopotentiating agent.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias do Colo/tratamento farmacológico , Metabolismo Energético/efeitos dos fármacos , Compostos de Platina/farmacologia , Piruvatos/farmacologia , Trifosfato de Adenosina/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino/farmacologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Desoxiglucose/farmacologia , Sinergismo Farmacológico , Glucose/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Proteína Supressora de Tumor p53/deficiência
15.
Exp Cell Res ; 312(9): 1581-9, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16529740

RESUMO

Stress-activated protein (SAP) kinases and the mitochondrial pro-apoptotic Bcl-2 protein Bak are important regulators of apoptosis. Reduced expression of Bak increases cellular resistance to the anticancer agent cisplatin, and we report here that mouse embryo fibroblasts deficient in the SAP kinase jnk1 are highly resistant to apoptosis induced by cisplatin. When human melanoma cells were treated with cisplatin, Bak function was found to be regulated in two distinct steps by two SAP kinases, MEKK1 and JNK1. The first of these steps involves MEKK1-controlled conformational activation of Bak. The second step leads to formation of 80-170 kDa Bak complexes correlating with apoptosis, and is controlled by JNK1. Inhibition of MEKK1 blocked the initial Bak conformational activation but did not block JNK1 activation, and deficiency in, or inhibition of, JNK1 did not prevent conformational activation of Bak. Furthermore, inducible expression of a constitutively active form of MEKK1 led to Bak conformational activation, but not to 80-170 kDa complexes. Consequently, apoptosis was delayed unless JNK was exogenously stimulated, indicating that Bak conformational activation is not necessarily an apoptotic marker. The two-step regulation of Bak revealed here may be important for tight control of mitochondrial factor release and apoptosis.


Assuntos
Apoptose/fisiologia , Transdução de Sinais/fisiologia , Proteína Killer-Antagonista Homóloga a bcl-2/fisiologia , Animais , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/deficiência , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Proteína 11 Semelhante a Bcl-2 , Caspase 3 , Caspases/metabolismo , Linhagem Celular Tumoral , Cisplatino/farmacologia , Citocromos c/metabolismo , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase Quinase 1/genética , MAP Quinase Quinase Quinase 1/metabolismo , MAP Quinase Quinase Quinase 1/fisiologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Proteína Quinase 8 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 8 Ativada por Mitógeno/deficiência , Proteína Quinase 8 Ativada por Mitógeno/fisiologia , Modelos Biológicos , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/efeitos dos fármacos , Sorbitol/farmacologia , Transfecção , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA