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2.
Therapie ; 79(1): 111-121, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38103949

RESUMO

Clinical trials often last several months or even several years. As the trial progresses, it can be tempting to find out whether the data obtained already answers the question posed at the start of the trial in order to stop inclusions or monitoring earlier. However, knowing and taking into account interim results can sometimes compromise the integrity of the results, which is counterproductive. To minimise this risk and ensure that the treatments are assessed reliably, safety and/or efficacy criteria are monitored during the study by a Data Monitoring Committee. After receiving the results confidentially, the Data Monitoring Committee assesses the benefit/risk ratio of the study treatment and recommends that the trial be continued, modified or terminated. Data Monitoring Committee members issuing these recommendations have an important responsibility: a hasty decision to end the trial may lead to inconclusive results unable to answer the initial question and, inversely, delaying the decision to end the trial may expose the subjects to potentially ineffective or even harmful interventions. The Data Monitoring Committee's task is therefore particularly complex. With this in mind, the round table discussion at the Giens workshops was a chance to review the scientific justification for creating Data Monitoring Committees and to recall the need for their members to receive comprehensive training on the complexities of multiple analyses, confidentiality requirements applying to the results and the need for them to be aware that recommendations to end a trial must be based on data that is robust enough to assess the benefit/risk ratio of the treatment studied.


Assuntos
Comitês de Monitoramento de Dados de Ensaios Clínicos , Humanos , Razão de Chances
3.
Br J Clin Pharmacol ; 89(7): 2295-2303, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37057679

RESUMO

AIMS: This study aimed to assess safety, tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) effects of ensovibep, a designed ankyrin repeat protein antiviral being evaluated as a COVID-19 treatment, in healthy volunteers in a first-in-human ascending single-dose study. METHODS: Subjects were dosed intravenously, in a randomized double-blinded manner, with either ensovibep at 3, 9 or 20 mg/kg or with placebo, and followed until Day 100. PK and safety were assessed throughout the study duration. Immunogenicity and PD via viral neutralization in serum were also assessed. RESULTS: All adverse events were of mild to moderate severity, and no serious adverse events were observed. One subject who received the 20-mg/kg dose presented with moderate hypersensitivity vasculitis 3 weeks after infusion, which fully resolved using standard procedures. In most subjects ensovibep showed expected mono-exponential decline with a half-life of around 2 weeks. Anti-drug antibodies were detected in 15 of 17 subjects, with the earliest onset detected on Day 29. Viral neutralization assays on subject serum showed effective viral neutralization over the first 3 weeks following dosing with titre values in a dose dependent manner. CONCLUSION: Ensovibep proved safe in this first-in-human safety study and exhibited PK and PD parameters consistent with the expected treatment period required for acute COVID-19 infection.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Antivirais/efeitos adversos , Repetição de Anquirina , Tratamento Farmacológico da COVID-19 , Voluntários Saudáveis , Método Duplo-Cego
4.
Int J Hematol ; 111(3): 409-416, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31858429

RESUMO

Patients with indolent non-Hodgkin lymphoma (iNHL) typically respond to first-line immunochemotherapy, but relapse is common. Treatment options for relapsed iNHL include chemotherapy ± rituximab and rituximab monotherapy. Lenalidomide plus rituximab (R2) is an immunomodulatory regimen that enhances rituximab-mediated cytotoxicity and improves clinical activity in iNHL. AUGMENT was a double-blind phase III randomized trial of R2 vs. rituximab + placebo (R-placebo) in patients with relapsed/refractory follicular lymphoma or marginal zone lymphoma who were not refractory to rituximab. The primary endpoint was progression-free survival (PFS). Data reported here focus on Japanese patients from AUGMENT and reflect 36 patients (n = 18, each group). PFS was superior in the R2 group, HR = 0.32 (95% CI 0.11-0.96). Median PFS was not reached (95% CI 19.7-NE) in the R2 group vs. 16.5 months (95% CI 11.3-30.6) in the R-placebo group. Grade 3/4 adverse events were more frequent in patients treated with R2 (67%) than with R-placebo (22%), primarily attributable to increased neutropenia (50% vs 17%). R2 resulted in significantly longer median PFS than R-placebo in Japanese patients with R/R iNHL, and the efficacy and the safety profile of R2 were similar to those reported in the global population.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Lenalidomida/administração & dosagem , Linfoma não Hodgkin/tratamento farmacológico , Rituximab/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Efeito Placebo , Resultado do Tratamento
5.
J Clin Oncol ; 37(14): 1188-1199, 2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-30897038

RESUMO

PURPOSE: Patients with indolent non-Hodgkin lymphoma typically respond well to first-line immunochemotherapy. At relapse, single-agent rituximab is commonly administered. Data suggest the immunomodulatory agent lenalidomide could increase the activity of rituximab. METHODS: A phase III, multicenter, randomized trial of lenalidomide plus rituximab versus placebo plus rituximab was conducted in patients with relapsed and/or refractory follicular or marginal zone lymphoma. Patients received lenalidomide or placebo for 12 cycles plus rituximab once per week for 4 weeks in cycle 1 and day 1 of cycles 2 through 5. The primary end point was progression-free survival per independent radiology review. RESULTS: A total of 358 patients were randomly assigned to lenalidomide plus rituximab (n = 178) or placebo plus rituximab (n = 180). Infections (63% v 49%), neutropenia (58% v 23%), and cutaneous reactions (32% v 12%) were more common with lenalidomide plus rituximab. Grade 3 or 4 neutropenia (50% v 13%) and leukopenia (7% v 2%) were higher with lenalidomide plus rituximab; no other grade 3 or 4 adverse event differed by 5% or more between groups. Progression-free survival was significantly improved for lenalidomide plus rituximab versus placebo plus rituximab, with a hazard ratio of 0.46 (95% CI, 0.34 to 0.62; P < .001) and median duration of 39.4 months (95% CI, 22.9 months to not reached) versus 14.1 months (95% CI, 11.4 to 16.7 months), respectively. CONCLUSION: Lenalidomide improved efficacy of rituximab in patients with recurrent indolent lymphoma, with an acceptable safety profile.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma de Zona Marginal Tipo Células B/tratamento farmacológico , Linfoma Folicular/tratamento farmacológico , Rituximab/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Feminino , Humanos , Lenalidomida/administração & dosagem , Lenalidomida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Placebos , Rituximab/efeitos adversos
6.
Clin Cancer Res ; 23(15): 4127-4137, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28381416

RESUMO

Purpose: Randomized, multicenter, open-label, phase 2/3 trial investigating lenalidomide versus investigator's choice (IC) in relapsed/refractory diffuse large B-cell lymphoma (DLBCL).Experimental Design: Patients with DLBCL who received ≥2 prior therapies were stratified by DLBCL subtype [germinal center B-cell (GCB) vs. non-GCB; determined by immunohistochemistry (IHC)] and then randomized 1:1 to lenalidomide (25 mg/day, 21 days of 28-day cycle) or IC (gemcitabine, rituximab, etoposide, or oxaliplatin). Crossover to lenalidomide was permitted for IC-treated patients with radiologically confirmed progressive disease. The primary endpoint was overall response rate (ORR). Progression-free survival (PFS), overall survival, and subtype analysis [GCB vs. activated B-cell (ABC)] using gene expression profiling (GEP) were exploratory endpoints.Results: Stage 1: 102 DLBCL patients (by IHC: non-GCB, n = 54; GCB, n = 48) received ≥1 dose of lenalidomide or IC. Hematologic treatment-emergent adverse events with lenalidomide versus IC included neutropenia (42.6%; 36.4%), anemia (33.3%; 47.3%), thrombocytopenia (24.1%; 43.6%), and leukopenia (5.6%; 12.7%), respectively. Overall, lenalidomide-treated patients had an ORR of 27.5% versus 11.8% in IC (ORRs were similar regardless of IHC-defined DLBCL subtype). Median PFS was increased in patients receiving lenalidomide (13.6 weeks) versus IC (7.9 weeks; P = 0.041), with greater improvements in non-GCB patients (15.1 vs. 7.1 weeks, respectively; P = 0.021) compared with GCB (10.1 vs. 9.0 weeks, respectively; P = 0.550).Conclusions: The clinical benefit of lenalidomide monotherapy in DLBCL patients was more evident in the non-GCB subtype. Exploratory analyses suggest that this preferential benefit was more pronounced in the GEP-defined ABC population, demonstrating a need for additional studies of lenalidomide in DLBCL using GEP subtyping. Clin Cancer Res; 23(15); 4127-37. ©2017 AACR.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Prognóstico , Talidomida/análogos & derivados , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Lenalidomida , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Modelos de Riscos Proporcionais , Rituximab/administração & dosagem , Talidomida/administração & dosagem , Talidomida/efeitos adversos , Resultado do Tratamento , Gencitabina
7.
PLoS One ; 9(8): e105354, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25133511

RESUMO

11ß-Hydroxysteroid dehydrogenases (11beta-HSD) modulate mineralocorticoid receptor transactivation by glucocorticoids and regulate access to the glucocorticoid receptor. The isozyme 11beta-HSD2 is selectively expressed in mineralocorticoid target tissues and its activity is reduced in various disease states with abnormal sodium retention and hypertension, including the apparent mineralocorticoid excess. As 50% of patients with essential hypertension are insulin resistant and hyperinsulinemic, we hypothesized that insulin downregulates the 11beta-HSD2 activity. In the present study we show that insulin reduced the 11beta-HSD2 activity in cancer colon cell lines (HCT116, SW620 and HT-29) at the transcriptional level, in a time and dose dependent manner. The downregulation was reversible and required new protein synthesis. Pathway analysis using mRNA profiling revealed that insulin treatment modified the expression of the transcription factor family C/EBPs (CCAAT/enhancer-binding proteins) but also of glycolysis related enzymes. Western blot and real time PCR confirmed an upregulation of C/EBP beta isoforms (LAP and LIP) with a more pronounced increase in the inhibitory isoform LIP. EMSA and reporter gene assays demonstrated the role of C/EBP beta isoforms in HSD11B2 gene expression regulation. In addition, secretion of lactate, a byproduct of glycolysis, was shown to mediate insulin-dependent HSD11B2 downregulation. In summary, we demonstrate that insulin downregulates HSD11B2 through increased LIP expression and augmented lactate secretion. Such mechanisms are of interest and potential significance for sodium reabsorption in the colon.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Regulação Neoplásica da Expressão Gênica , Insulina/metabolismo , Ácido Láctico/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Linhagem Celular Tumoral , Colo/metabolismo , Colo/patologia , Neoplasias do Colo/patologia , Regulação Enzimológica da Expressão Gênica , Humanos , Transdução de Sinais
8.
Clin Lung Cancer ; 14(1): 34-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22633220

RESUMO

INTRODUCTION: Small-cell lung cancer (SCLC) is a highly vascularized tumor. ASA404 is a tumor vascular disrupting agent. This is the first trial to report the effects of combining chemotherapy with ASA404 in SCLC. METHODS: Patients with untreated metastatic SCLC were treated with carboplatin (area under curve, 6) plus paclitaxel (175 mg/m(2)) plus ASA404 (1800 mg/m(2)) on day 1 every 21 days for up to 6 cycles. The primary endpoint was the progression-free survival (PFS) rate at 24 weeks. RESULTS: Median age was 61 years; 53% were women, 41% had weight loss; and 96% had a performance status of 0-1. Twelve patients completed all 6 cycles, and most adverse events were related to chemotherapy. Median PFS and time to progression were 7.0 months (95% CI, 5.7-9.4 months) and 7.5 months (95% CI, 5.7-9.4 months), respectively. The progression-free survival (PFS) rate at 24 weeks was 41% (95% CI, 18%-65%). The overall response rate was 94%. The median overall survival time was 14.2 months (95% CI, 8.2-16.0 months) and 1-year survival was 57%. The median follow-up time was 17.7 months. Due to negative results with ASA404 in non-small-cell lung cancer trials, the trial was stopped prematurely after 17 of 56 planned patients were being accrued. CONCLUSIONS: This is the first report of a clinical trial with a vascular disrupting agent in SCLC. No unexpected toxicity was observed. PFS was not prolonged with carboplatin and paclitaxel plus ASA404.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/secundário , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carboplatina/administração & dosagem , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Paclitaxel/administração & dosagem , Carcinoma de Pequenas Células do Pulmão/secundário , Resultado do Tratamento , Xantonas/administração & dosagem
9.
FASEB J ; 21(13): 3618-28, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17551100

RESUMO

Reduced activity of 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) plays a role in essential hypertension and the sensitivity of blood pressure to dietary salt. Nonconservative mutations in the coding region are extremely rare and do not explain the variable 11beta-HSD2 activity. We focused therefore on the 5'-regulatory region and identified and characterized the first promoter polymorphisms. Transfections of variants G-209A and G-126A into SW620 cells reduced promoter activity and affinity for activators nuclear factor 1 (NF1) and Sp1. Chromatin immunoprecipitation revealed Sp1, NF1, and glucocorticoid receptor (GR) binding to the HSD11B2 promoter. Dexamethasone induced expression of mRNA and activity of HSD11B2. GR and/or NF1 overexpression increased endogenous HSD11B2 mRNA and activity. GR complexes cooperated with NF1 to activate HSD11B2, an effect diminished in the presence of the G-209A variant. When compared to salt-resistant subjects (96), salt-sensitive volunteers (54) more frequently had the G-209A variant, higher occurrence of alleles A4/A7 of polymorphic microsatellite marker, and higher urinary ratios of cortisol to cortisone metabolites. First, we conclude that the mechanism of glucocorticoid-induced HSD11B2 expression is mainly mediated by cooperation between GR and NF1 on the HSD11B2 promoter and, second, that the newly identified promoter variants reduce activity and cooperation of cognate transcription factors, resulting in diminished HSD11B2 transcription, an effect favoring salt sensitivity.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Cloreto de Sódio na Dieta/farmacologia , Sequência de Bases , Imunoprecipitação da Cromatina , Primers do DNA , Dexametasona/farmacologia , Humanos , Plasmídeos , Reação em Cadeia da Polimerase , RNA Mensageiro/genética
10.
J Am Soc Nephrol ; 16(12): 3507-16, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16251242

RESUMO

Hypertension and sodium retention are features of a diminished 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). The activity of this enzyme is reduced in various disease states with abnormal renal sodium retention and hypertension, including preeclampsia. ATP release to the extracellular compartment is observed with shear stress, inflammation, and placental ischemia. It was hypothesized that ATP downregulates 11beta-HSD2 activity. For that purpose, cell lines from different tissues that previously were used to study the regulation of 11beta-HSD2 were investigated: JEG-3, a vascular trophoblastic; LLCPK1, a renal tubular; and SW620, a colonic epithelial cell line. The 11beta-HSD2 activity, assessed by the conversion of 3H-cortisol to cortisone, was reversibly reduced during incubation with ATP or its stable analogue ATPgammaS in intact JEG-3 and LLCPK1, but not in SW620 cells. In JEG-3 cells, the purinergic antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid but not suramin reversed the inhibition. Incubation with UTP and ADP and their degradation products including adenosine and alpha,beta-methylene-ATP did not inhibit 11beta-HSD2 activity. In contrast, 11beta-HSD2 activity increased almost 2.5-fold after incubation with 2'-methylthio-ATP. This indicates a bidirectional regulation by nucleotides via purinergic receptors. In JEG-3 cells, ATP/ATPgammaS did not alter 11beta-HSD2 promoter activity but reduced 11beta-HSD2 protein and mRNA concentration and half-life, suggesting a posttranscriptional regulation. In conclusion, ATP inhibits cell type specifically via purinergic receptors the expression and activity of the 11beta-HSD2 by a posttranscriptional mechanism.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 2/efeitos dos fármacos , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Trifosfato de Adenosina/farmacologia , Células Epiteliais/metabolismo , Receptores Purinérgicos , Sódio/metabolismo , Western Blotting , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/citologia , Feminino , Humanos , Hipertensão Induzida pela Gravidez/enzimologia , Hipertensão Induzida pela Gravidez/fisiopatologia , Mucosa Intestinal/citologia , Túbulos Renais/citologia , Gravidez , RNA Mensageiro/análise , Valores de Referência , Sensibilidade e Especificidade , Trofoblastos/citologia
11.
J Endocrinol ; 183(3): 535-50, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15590980

RESUMO

We reported previously that insulin inhibits the stimulatory effect of high glucose on the expression of angiotensinogen (ANG) gene in both rat immortalized renal proximal tubular cells (IRPTCs) and non-diabetic rat renal proximal tubular cells (RPTCs), but has no effect in diabetic rat RPTCs. In the present study we investigated whether hyperglycaemia-induced resistance to the insulin-induced inhibition of expression of the ANG gene is mediated via the generation of reactive oxygen species (ROS) in RPTCs. Rat IRPTCs were cultured for 2 weeks in high-glucose (25 mM) or normal-glucose (5 mM) medium plus angiotensin II (Ang II) with or without a superoxide scavenger (tiron), or inhibitors of: NADPH oxidase (diphenylene iodinium, DPI), Ang II type 1 and 2 receptors (losartan and PD123319), angiotensin-converting enzyme (perindopril), protein kinase C (GF 109203X), or glutamine:fructose-6-phosphate amino-transferase (azaserine). Cellular generation of ROS, and ANG and renin mRNA levels were assessed by lucigenin assay and specific reverse transcriptase-PCR respectively. Phosphorylation of p44/42 mitogen-activated protein kinase (p44/42 MAPK) was evaluated by western blotting. Prolonged exposure of IRPTCs to high concentrations of glucose or Ang II evoked generation of ROS and resistance to the insulin-induced inhibition of expression of the ANG gene and of p44/42 MAPK phosphorylation. Co-incubation of IRPTCs with tiron, DPI, losartan, PD123319, perindopril, GF 109203X or azaserine prevented ROS generation, restoring the inhibitory action of insulin on ANG gene expression and on p44/42 MAPK phosphorylation. In conclusion, our studies demonstrate that blockade of both ROS generation and activation of the intrarenal renin-angiotensin system improves the inhibitory action of insulin on ANG gene expression in IRPTCs in conditions of high glucose.


Assuntos
Angiotensinogênio/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/farmacologia , Insulina/metabolismo , Túbulos Renais Proximais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico/farmacologia , Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Azasserina/farmacologia , Linhagem Celular , Imidazóis/farmacologia , Indicadores e Reagentes/farmacologia , Indóis/farmacologia , Losartan/farmacologia , Maleimidas/farmacologia , Perindopril/farmacologia , Proteína Quinase C/antagonistas & inibidores , Piridinas/farmacologia , Ratos , Renina/genética
12.
Clin Chim Acta ; 344(1-2): 115-21, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15149879

RESUMO

BACKGROUND: trans-Resveratrol, or 3,5,4'trihydroxy-trans-stilbene, is a polyphenolic compound that seems to provide a protective effect against several types of cancer, notably breast cancer. Through its phytoestrogenic properties it regulates the expression of hormone-dependent genes, such as the oncosuppressor BRCA1, in breast cells. This gene is involved in the majority of hereditary breast cancer, as well as sporadic cancers. METHODS: We used three human breast tumor cell lines (HBL100, MCF7 and MBA-MB-231) and one breast cell line (MCF10a) derived from a fibrocystic disease to study in vitro the effect of resveratrol on the transcription of a group of genes whose proteins interact in different pathways with BRCA1. BRCA1, BRCA2, ER alpha, ER beta, p53, p21(waf1/cip1), CBP/P300, RAD51, pS2 and Ki67 mRNA were quantified using real-time quantitative RT-PCR with an ABI 7700 apparatus. RESULTS: Resveratrol modulated the expression of these genes in a pattern dependent on the status of alpha and beta estrogen receptors. These results show that resveratrol regulates gene expression via the estrogen receptor pathway and also an undetermined pathway. CONCLUSION: Thus, resveratrol seems to have an effect on breast tumor cell lines, on a fibrocystic cell line by affecting several factors regulating the function of BRCA1.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Estilbenos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Doença da Mama Fibrocística/tratamento farmacológico , Doença da Mama Fibrocística/genética , Doença da Mama Fibrocística/patologia , Humanos , Proteínas de Neoplasias/genética , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Receptores de Estrogênio/fisiologia , Resveratrol , Transcrição Gênica/efeitos dos fármacos , Proteínas Supressoras de Tumor/genética
13.
Endocrinology ; 144(10): 4338-49, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12960040

RESUMO

The present study investigated whether activation of the hexosamine biosynthesis pathway might mediate at least in part the high glucose effect on angiotensinogen (ANG) gene expression and immortalized renal proximal tubular cell (IRPTC) hypertrophy. IRPTC were cultured in monolayer. ANG, renin, and beta-actin mRNA expression were determined by specific RT-PCR assays. Phosphorylation of p38 MAPK, activating transcription factor-2 (ATF-2), and cAMP-responsive element-binding protein (CREB) was determined by Western blot analysis. Cell hypertrophy was assessed by flow cytometry, intracellular p27kip1 protein levels, and [3H]leucine incorporation into proteins. Glucosamine stimulated ANG and renin mRNA expression and enhanced p38 MAPK, ATF-2, and CREB phosphorylation in normal glucose (5 mm) medium. Azaserine and 6-diazo-5-oxo-l-norleucine (inhibitors of glutamine: fructose-6-phosphate amino transferase enzyme) blocked the stimulatory effect of high glucose, but not that of glucosamine, on ANG gene expression in IRPTCs. SB 203580 (a specific p38 MAPK inhibitor) attenuated glucosamine action on ANG gene expression as well as p38 MAPK and ATF-2 phosphorylation, but not that of CREB. GF 109203X and calphostin C (inhibitors of protein kinase C) blocked the effect of glucosamine on ANG gene expression and CREB phosphorylation, but had no impact on p38 MAPK and ATF-2 phosphorylation. Finally, both glucosamine and high glucose induced IRPTC hypertrophy. The hypertrophic effect of glucosamine was blocked in the presence of GF 109203X, but not azaserine and SB 203580. In contrast, the hypertrophic effect of high glucose was blocked in the presence of azaserine and GF 109203X, but not SB203580. Our studies demonstrate that the stimulatory effect of high glucose on ANG gene expression and IRPTC hypertrophy may be mediated at least in part via activation of hexosamine biosynthesis pathway signaling.


Assuntos
Angiotensinogênio/genética , Expressão Gênica/efeitos dos fármacos , Glucose/administração & dosagem , Hexosaminas/biossíntese , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Fator 2 Ativador da Transcrição , Angiotensinogênio/metabolismo , Animais , Azasserina/farmacologia , Linhagem Celular Transformada , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Diazo-Oxo-Norleucina/farmacologia , Relação Dose-Resposta a Droga , Glucosamina/farmacologia , Hipertrofia , Túbulos Renais Proximais/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Fatores de Transcrição/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
14.
Br J Nutr ; 87(4): 281-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12064337

RESUMO

Current evidence strongly supports a role for the breast tumour suppressor genes, BRCA1 and BRCA2, in both normal development and carcinogenesis. In vitro observations reported that BRCA1 and BRCA2 are expressed in a cell cycle-dependent manner. Interestingly, differences in the actions of n-3 and n-6 polyunsaturated fatty acids have been observed: while the n-3 polyunsaturated fatty acids have been described to reduce pathological cell growth, the n-6 polyunsaturated fatty acids have been found to induce tumour proliferation. Here, we examined the expression of BRCA1 and BRCA2 in breast cell lines after treatment with polyunsaturated fatty acids. Real-time quantitative polymerase chain reaction determinations conclusively demonstrated increases in BRCA1 and BRCA2 mRNA expressions in MCF7 and MDA-MB 231 tumour cell lines after treatment with n-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but no variation was noticed with the n-6 polyunsaturated fatty acid (arachidonic acid). On the other hand, no variation of the expression of BRCA1 and BRCA2 mRNA was detected in MCF10a normal breast cell line treated by polyunsaturated fatty acids. The level of BRCA1 and BRCA2 proteins quantified by affinity chromatography remained unchanged in tumour (MCF7, MDA-MB 231) and normal (MCF10a) breast cell lines. We suggest the presence of a possible transcriptional or post-transcriptional regulation of BRCA1 and BRCA2 after n-3 polyunsaturated fatty acid treatment in breast tumour cells.


Assuntos
Neoplasias da Mama/genética , Mama/metabolismo , Ácidos Graxos Insaturados/farmacologia , Genes BRCA1/efeitos dos fármacos , Genes BRCA2/efeitos dos fármacos , Ácido Araquidônico/farmacologia , Proteína BRCA1/análise , Proteína BRCA2/análise , Neoplasias da Mama/metabolismo , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Cromatografia de Afinidade , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/análise , Células Tumorais Cultivadas
15.
Biochim Biophys Acta ; 1586(1): 50-6, 2002 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-11781149

RESUMO

We evaluated BRCA1 and BRCA2 oncosuppressor protein expression in 26 milk samples in women just after delivery. The quantification of BRCA1 and BRCA2 proteins was performed in isolated milk fat globules using an affinity chromatography strategy. The amounts of BRCA1 and BRCA2 proteins were found to be similar. We explained the presence of BRCA1 and BRCA2 proteins in human milk fat globules by the fact that they are formed by exocytosis of lipids from epithelial cells of the mammary gland and are enveloped by plasma membrane from the apical part of the milk-secreting cells. This raises the possibility that BRCA1 and BRCA2 proteins are a protective response to proliferation and play a possible role in newborn nutrition.


Assuntos
Proteína BRCA1/análise , Proteína BRCA2/análise , Glicolipídeos/química , Glicoproteínas/química , Leite Humano/química , Proteína BRCA1/imunologia , Proteína BRCA2/imunologia , Cromatografia de Afinidade , Parto Obstétrico , Feminino , Glicolipídeos/isolamento & purificação , Glicoproteínas/isolamento & purificação , Humanos , Gotículas Lipídicas , Fenômenos Fisiológicos da Nutrição , Fatores de Tempo
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