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1.
ESMO Open ; 9(6): 103476, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38833968

RESUMO

BACKGROUND: An important unmet need for new treatment options remains for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M-HNSCC) previously treated with both platinum-based chemotherapy and anti-programmed cell death protein 1 (PD-1) antibody. Retrospective studies suggest that previous treatment with immune checkpoint inhibitor might augment the efficacy of subsequent chemotherapy. Here, we conducted a phase II trial aimed to evaluate the efficacy and safety of paclitaxel plus biweekly cetuximab for patients in this setting. PATIENTS AND METHODS: This was a single-arm, multicenter, phase II trial. Key eligibility criteria were R/M-HNSCC, and previous treatment with both platinum-based chemotherapy and PD-1 antibody. Paclitaxel plus biweekly cetuximab consisted of weekly paclitaxel 100 mg/m2 (days 1, 8, 15) and biweekly cetuximab 500 mg/m2 (days 1, 15) with a cycle of 28 days until progression or unacceptable toxicity. Primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and adverse events (AEs) (Common Terminology Criteria for Adverse Events version 5.0). RESULTS: Between August 2020 and August 2022, 35 patients were enrolled, of whom 33 were assessable for response. ORR was 69.6% (95% confidence interval 51.2% to 84.4%). With a median follow-up period for survivors of 16.6 months, median PFS and OS were 5.5 and 13.3 months, respectively. DCR was 93.7%. Twenty-three patients (65%) experienced grade 3 or 4 AEs, including neutropenia (34%), infection (14%), leukopenia (11%), mucositis (8%), and pneumonitis (8%). Eight patients discontinued study treatment due to treatment-related AEs, and no treatment-related death was observed. CONCLUSIONS: Paclitaxel plus biweekly cetuximab showed highly encouraging efficacy and manageable toxicities in R/M-HNSCC patients previously treated with both platinum-based chemotherapy and PD-1 antibody. This combination therapy warrants further investigation in this setting.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Cetuximab , Neoplasias de Cabeça e Pescoço , Paclitaxel , Humanos , Cetuximab/administração & dosagem , Cetuximab/uso terapêutico , Cetuximab/farmacologia , Paclitaxel/uso terapêutico , Paclitaxel/administração & dosagem , Paclitaxel/farmacologia , Masculino , Pessoa de Meia-Idade , Feminino , Idoso , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Adulto , Recidiva Local de Neoplasia/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/administração & dosagem
2.
AJNR Am J Neuroradiol ; 41(5): 828-835, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32381548

RESUMO

BACKGROUND AND PURPOSE: Recanalization after coil embolization is widely studied. However, there are limited data on how recanalized aneurysms rupture. Herein, we describe our experience with the rupture of recanalized aneurysms and discuss the type of recanalized aneurysms at greatest rupture risk. MATERIALS AND METHODS: A total of 426 unruptured aneurysms and 169 ruptured aneurysms underwent coil embolization in our institution between January 2009 and December 2017. Recanalization occurred in 38 (8.9%) of 426 unruptured aneurysms (unruptured group) and 37 (21.9%) of 169 ruptured aneurysms (ruptured group). The Modified Raymond-Roy classification on DSA was used to categorize the recanalization type. Follow-up DSA was scheduled until 6 months after treatment, and follow-up MRA was scheduled yearly. If recanalization was suspected on MRA, DSA was performed. RESULTS: In the unruptured group, the median follow-up term was 74.0 months. Retreatment for recanalization was performed in 18 aneurysms. Four of 20 untreated recanalized aneurysms (0.94% of total coiled aneurysms) ruptured. In untreated recanalized aneurysms, class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .025). In the ruptured group, the median follow-up term was 28.0 months. Retreatment for recanalization was performed in 16 aneurysms. Four of 21 untreated recanalized aneurysms (2.37% of total coiled aneurysms) ruptured. Class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .02). CONCLUSIONS: The types of recanalization after coil embolization may be predictors of rupture. Coiled aneurysms with class IIIb recanalization should undergo early retreatment because of an increased rupture risk.


Assuntos
Aneurisma Roto/terapia , Embolização Terapêutica , Aneurisma Intracraniano/terapia , Complicações Pós-Operatórias , Adulto , Idoso , Prótese Vascular , Embolização Terapêutica/instrumentação , Embolização Terapêutica/métodos , Procedimentos Endovasculares/instrumentação , Procedimentos Endovasculares/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Recidiva , Retratamento , Estudos Retrospectivos , Resultado do Tratamento
3.
Int J Clin Oncol ; 25(7): 1270-1277, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32277393

RESUMO

BACKGROUND: Nivolumab improves overall survival (OS) in patients with platinum-refractory recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC). In one study, however, Kaplan-Meier OS and progression-free survival (PFS) curves for the nivolumab and cytotoxic agent arms crossed at 3-6 months, suggesting that patients with initial resistance to immunotherapy might have better outcomes with cytotoxic treatment. Here, we explored the conditions and candidates which are predictive of nivolumab outcomes in R/M HNSCC. METHODS: We retrospectively reviewed the clinical records of 27 consecutive R/M HNSCC patients treated with nivolumab from 2014 to 2018. Tumor size was evaluated by RECIST ver.1.1. Tumor growth rate (Gr) was defined as 3log(D0/Dpre)/t, where D0 and Dpre are the sum of the diameters of the target lesions (SumTLs) at baseline and pre-baseline, and t is time, with 1t defined as 4 weeks. RESULTS: Twenty-five patients were enrolled. Survival was significantly worse in patients with disease progression within 3 months. Outcomes appeared poorer in patients with higher pre-treatment Gr and bigger SumTLs at baseline. We therefore explored the association between prognosis, Gr and SumTLs. Recursive partitioning analysis showed that the characteristics of patients with disease progression after 3 months were Gr < 0.76 and SumTLs < 31.0 mm. Further, Gr < 0.76 and SumTLs < 31.0 mm was associated with significantly longer PFS (p = 0.01) and OS (p < 0.01). CONCLUSIONS: These results suggest that Gr and SumTLs at baseline are significantly associated with OS and PFS in R/M HNSCC patients treated with nivolumab.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Nivolumabe/uso terapêutico , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imunoterapia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Resultado do Tratamento , Carga Tumoral
4.
Oncogene ; 33(1): 55-64, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23178487

RESUMO

The regulation of mRNA deadenylation constitutes a pivotal mechanism of the post-transcriptional control of gene expression. Here we show that the antiproliferative protein Tob, a component of the Caf1-Ccr4 deadenylase complex, is involved in regulating the expression of the proto-oncogene c-myc. The c-myc mRNA contains cis elements (CPEs) in its 3'-untranslated region (3'-UTR), which are recognized by the cytoplasmic polyadenylation element-binding protein (CPEB). CPEB recruits Caf1 deadenylase through interaction with Tob to form a ternary complex, CPEB-Tob-Caf1, and negatively regulates the expression of c-myc by accelerating the deadenylation and decay of its mRNA. In quiescent cells, c-myc mRNA is destabilized by the trans-acting complex (CPEB-Tob-Caf1), while in cells stimulated by the serum, both Tob and Caf1 are released from CPEB, and c-Myc expression is induced early after stimulation by the stabilization of its mRNA as an 'immediate-early gene'. Collectively, these results indicate that Tob is a key factor in the regulation of c-myc gene expression, which is essential for cell growth. Thus, Tob appears to function in the control of cell growth at least, in part, by regulating the expression of c-myc.


Assuntos
Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/fisiologia , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Regiões 3' não Traduzidas , Sequência de Bases , Meios de Cultura Livres de Soro , Células HeLa , Humanos , Dados de Sequência Molecular , Poliadenilação , Ligação Proteica , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-myc/genética , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estresse Fisiológico
6.
Dis Esophagus ; 20(6): 478-86, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17958722

RESUMO

Sivelestat sodium hydrate is a selective inhibitor of neutrophil elastase (NE), and is effective in acute lung injury associated with systemic inflammatory response syndrome (SIRS). The effect of Sivelestat for postoperative clinical courses after transthoracic esophagectomy was investigated. Consecutive patients with carcinoma of the thoracic esophagus who underwent transthoracic esophagectomy between 2003 and 2004 were assigned to the Sivelestat-treated group (n = 18), and those between 1998 and 2003 were assigned to the control group (n = 25). The morbidity rate, duration of postoperative SIRS, mechanical ventilation, and intensive care unit (ICU) stay, and the sum of the sequential organ failure assessment scores at all time points after the operation were compared. Serum NE activities and serum concentrations of TNF-alpha, IL-1beta, IL-6, and high mobility group box chromosomal protein 1 (HMGB1) were measured. Postoperative complications developed in three patients in the control group, and one in the Sivelestat-treated group. The durations of SIRS, mechanical ventilation, and ICU stay were significantly shorter in the Sivelestat-treated group. Even in patients without complications, the durations of mechanical ventilation, and ICU stay were also significantly shorter, and the arterial oxygen pressure/fraction of inspired oxygen ratio at postoperative day 1 was significantly higher in the Sivelestat-treated group. Serum NE activities and serum concentrations of IL-1beta, IL-6, and HMGB1 were significantly suppressed in the Sivelestat-treated group. Postoperative Sivelestat treatment after transthoracic esophagectomy improves the condition of SIRS and postoperative clinical courses, even in patients without complications.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Glicina/análogos & derivados , Elastase de Leucócito/antagonistas & inibidores , Sulfonamidas/uso terapêutico , Idoso , Terapia Combinada , Feminino , Glicina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Resultado do Tratamento
7.
Neurogastroenterol Motil ; 19(4): 288-300, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17391245

RESUMO

The rhythmic motility of the intestine is regulated by the interstitial cells of Cajal (ICC) and the enteric nervous system. Rhythmic motility is considered to occur after the differentiation of mesenchymal progenitor cells into ICC during the late embryonic period. In this study, we successfully reconstructed a gut-like tissue demonstrating rhythmic contractions by culturing dispersed cells enzymatically isolated from the mouse intestine during the mid-embryonic period. These intestinal cells were reconstituted into a collagen gel at high density, made to proliferate considerably, and grew into a gut-like tissue after 1 week of culturing. The reconstituted tissue showed rhythmic contractions and stained positive for the specific marker proteins of neurones and ICC, PGP9.5 and c-Kit. The tissue also demonstrated network formation by developing nerve cells and ICC. Moreover, in the presence of nifedipine, c-Kit-immunopositive cells showed spontaneous Ca(2+) oscillation, which is considered to be coupled to the electrical activity that corresponds to slow waves. Therefore, this culture system may be of use in elucidating the developmental mechanisms of gastrointestinal motility.


Assuntos
Intestinos/fisiologia , Contração Muscular/fisiologia , Animais , Cálcio/metabolismo , Células Cultivadas , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/genética , Intestinos/embriologia , Camundongos , Camundongos Endogâmicos ICR , Músculo Liso/embriologia , Músculo Liso/fisiologia , Gravidez , Proteínas Proto-Oncogênicas c-kit/genética , RNA/genética , RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ubiquitina Tiolesterase/genética
8.
Thorac Cardiovasc Surg ; 55(1): 53-4, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17285475

RESUMO

A 45-year-old female, who had undergone emergency drainage of a cyst, complained of severe dyspnea. Chest computed tomography scans showed a large mass, compressing the right pulmonary artery, superior vena cava, and tracheal bifurcation. Subtotal resection of the cyst wall was carried out due to dense adhesion to adjacent structures. Immediately after surgery, her symptoms resolved completely. Mediastinal bronchogenic cysts in the subcarinal space can cause severe respiratory distress from airway and vascular compression.


Assuntos
Obstrução das Vias Respiratórias/complicações , Cisto Broncogênico/complicações , Doenças do Mediastino/complicações , Artéria Pulmonar , Síndrome do Desconforto Respiratório/etiologia , Obstrução das Vias Respiratórias/diagnóstico por imagem , Cisto Broncogênico/diagnóstico por imagem , Cisto Broncogênico/cirurgia , Constrição Patológica/complicações , Constrição Patológica/diagnóstico por imagem , Diagnóstico Diferencial , Drenagem , Feminino , Humanos , Doenças do Mediastino/diagnóstico por imagem , Doenças do Mediastino/cirurgia , Pessoa de Meia-Idade , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Toracotomia , Tomografia Computadorizada por Raios X
9.
Phys Rev Lett ; 91(26 Pt 1): 261601, 2003 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-14754037

RESUMO

We report the observation of the flavor-changing neutral current decay B-->K(*)l(+)l(-) and an im-proved measurement of the decay B-->Kl(+)l(-), where l represents an electron or a muon, with a data sample of 140 fb(-1) accumulated at the Upsilon(4S) resonance with the Belle detector at KEKB. The results for the branching fractions are B(B-->K(*)l(+)l(-))=(11.5(+2.6)(-2.4)+/-0.8+/-0.2)x10(-7) and B(B-->Kl(+)l(-))=(4.8(+1.0)(-0.9)+/-0.3+/-0.1)x10(-7), where the first error is statistical, the second is systematic and the third is from model dependence.

10.
Arterioscler Thromb Vasc Biol ; 21(11): 1759-63, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11701462

RESUMO

The plasma level of interleukin-6 (IL-6) is elevated in patients with acute coronary syndromes and has prognostic value. Thrombin is a potent mitogen for vascular smooth muscle cells (VSMCs) and plays an important role in the progression of atherosclerosis. We examined the mechanism of thrombin-induced IL-6 expression in VSMCs. Thrombin induced IL-6 mRNA and protein expression in a dose-dependent manner. Pharmacological inhibition of extracellular signal-regulated protein kinase (ERK), p38 mitogen-activated protein kinase (MAPK), or epidermal growth factor receptor (EGF-R) suppressed the thrombin-induced IL-6 expression. Deletion and mutation analysis of the promoter region of the IL-6 gene by using luciferase as a reporter showed that the DNA segment between -228 and -150 bp containing the cAMP response element (CRE) site played a critical role. Thrombin also induced phosphorylation of CRE binding protein (CREB) in an ERK- and a p38 MAPK-dependent manner. Overexpression of the dominant-negative form of CREB inhibited thrombin-induced IL-6 mRNA expression. These results suggest that the CRE site and CREB play an important role in thrombin-induced IL-6 gene expression in VSMCs. Transactivation of EGF-R and activation of ERK and p38 MAPK are involved in this process. CREB may be a novel transcription factor that regulates thrombin-induced gene expression.


Assuntos
AMP Cíclico/fisiologia , Interleucina-6/genética , Músculo Liso Vascular/metabolismo , Elementos de Resposta , Trombina/farmacologia , Ativação Transcricional , Animais , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Receptores ErbB/metabolismo , Interleucina-6/biossíntese , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Mutação , Fosforilação , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley
11.
Arterioscler Thromb Vasc Biol ; 21(11): 1764-9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11701463

RESUMO

Thrombin is a potent mitogen for vascular smooth muscle cells (VSMCs) and plays an important role in the progression of atherosclerosis. Although recent reports have suggested that cAMP response element-binding protein (CREB) is necessary for the survival of neuronal cells, the role of CREB in VSMC proliferation is not determined. We examined the role of CREB in thrombin-induced VSMC proliferation and the effect of thrombin on phosphorylation of CREB at Ser133, which is a critical marker for activation by Western blot analysis. Thrombin induced phosphorylation of CREB in a dose-dependent manner. An oligopeptide, SFLLRN, which activates the thrombin receptor, also induced the phosphorylation of CREB. Inhibition of extracellular signal-regulated protein kinase or inhibition of p38 mitogen-activated protein kinase suppressed the thrombin-induced CREB phosphorylation. Inhibition of the epidermal growth factor receptor by AG1478 also inhibited the thrombin-induced CREB phosphorylation. Overexpression of the dominant-negative form of CREB inhibited thrombin-induced c-fos mRNA expression and incorporation of [(3)H]thymidine and [(3)H]leucine. These results suggest that CREB-dependent gene transcription plays a critical role in thrombin-induced proliferation and hypertrophy of VSMCs. Transactivation of the epidermal growth factor receptor and 2 mitogen-activated protein kinase pathways are involved in this process. CREB may be a novel transcription factor mediating the vascular remodeling process induced by thrombin.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Músculo Liso Vascular/metabolismo , Trombina/farmacologia , Adenoviridae/genética , Animais , Divisão Celular , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , DNA/biossíntese , Vetores Genéticos , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Mutação , Fosforilação , Fosfosserina/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Ativação Transcricional
12.
Kyobu Geka ; 54(9): 769-72, 2001 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-11517547

RESUMO

19 surgically treated cases with bronchopulmonary carcinoid in our hospital were studied clinically, and we discussed the criteria of limited operation for typical carcinoid. 11 cases had typical carcinoid and 8 had atypical. All patients of typical type were alive with no recurrence. No lymph node metastasis was revealed in all cases of typical type. On the contrary, in cases of atypical type, 1 had n 2 disease and 1 had distant metastasis. The five survival rates of patients with typical carcinoid was 100%, and significantly better than that of patients with atypical, 27%. Therefore, patients with typical carcinoid can be cured by limited operation, but radical operation should be indicated for atypical carcinoid.


Assuntos
Neoplasias Brônquicas/cirurgia , Tumor Carcinoide/cirurgia , Neoplasias Pulmonares/cirurgia , Pneumonectomia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonectomia/métodos
13.
Hypertension ; 38(1): 100-4, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11463768

RESUMO

Recently, it was shown that Rho-kinase plays an important role in blood pressure regulation. However, it is not known whether Rho-kinase is involved in atherogenesis. Monocyte chemoattractant protein-1 (MCP-1) is an important chemokine that regulates monocyte recruitment and atherogenesis. Therefore, we examined the role of Rho and Rho-kinase in the angiotensin (Ang) II-induced expression of MCP-1. Ang II dose- and time-dependently enhanced the expression of MCP-1 mRNA and the protein production in vascular smooth muscle cells. CV11974, an Ang II type 1 receptor (AT(1)-R) specific antagonist inhibited the enhancement of MCP-1 expression by Ang II, suggesting that the effect of Ang II is mediated by the AT(1)-R. Botulinum C3 exotoxin, a specific inhibitor of Rho, suppressed Ang II-induced MCP-1 production. To examine the role of Rho-kinase in Ang II-induced MCP-1 expression, we used adenovirus-mediated overexpression of the dominant negative mutant of Rho-kinase (AdDNRhoK) or Y-27632, a specific inhibitor of Rho-kinase. Both AdDNRhoK and Y-27632 strongly inhibited Ang II-induced MCP-1 expression. Although inhibition of extracellular signal-regulated protein kinase (ERK) by PD 098,059 also inhibited Ang II-induced MCP-1 expression, Y-27632 did not affect Ang II-induced activation of ERK. These results indicate that Rho-kinase plays a critical role in Ang II-induced MCP-1 production independent of ERK. The Rho-Rho-kinase pathway may be a novel target for the inhibition of Ang II signaling and the treatment of atherosclerosis.


Assuntos
Angiotensina II/farmacologia , Quimiocina CCL2/biossíntese , Músculo Liso Vascular/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Amidas/farmacologia , Animais , Células Cultivadas , Quimiocina CCL2/genética , Ativação Enzimática/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Piridinas/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Quinases Associadas a rho , Proteína rhoA de Ligação ao GTP
14.
Hypertension ; 37(2 Pt 2): 535-40, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11230331

RESUMO

Recent studies suggest a crucial role of reactive oxygen species (ROS) for the signaling of angiotensin (Ang) II through Ang II type 1 receptor (AT(1)-R). However, the role of ROS in the regulation of AT(1)-R expression has not been explored. In this study, we examined the effect of an antioxidant on the homologous downregulation of AT(1)-R by Ang II. Ang II (10(-6) mol/L) decreased AT(1)-R mRNA with a peak suppression at 6 hours of stimulation in rat aortic vascular smooth muscle cells. Preincubation of vascular smooth muscle cells with N:-acetylcysteine (NAC), a potent antioxidant, almost completely inhibited the Ang II-induced downregulation of AT(1)-R mRNA. The effect of NAC was due to stabilization of the AT(1)-R mRNA that was destabilized by Ang II. The Ang II-induced AT(1)-R mRNA downregulation was also blocked by PD98059, an extracellular signal-regulated protein kinase (ERK) kinase inhibitor. Ang II-induced ERK activation was inhibited by NAC as well as by PD98059. Exogenous H(2)O(2) also suppressed AT(1)-R mRNA. These results suggest that the production of ROS and the activation of ERK are critical for the downregulation of AT(1)-R mRNA. The generation of ROS through stimulation of AT(1)-R not only mediates signaling of Ang II but also may play a crucial role in the adaptation process of AT(1)-R to the sustained stimulation of Ang II.


Assuntos
Angiotensina II/farmacologia , Músculo Liso Vascular/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Angiotensina/metabolismo , Acetilcisteína/farmacologia , Angiotensina II/antagonistas & inibidores , Bloqueadores do Receptor Tipo 1 de Angiotensina II , Bloqueadores do Receptor Tipo 2 de Angiotensina II , Antagonistas de Receptores de Angiotensina , Animais , Antioxidantes/farmacologia , Ligação Competitiva , Células Cultivadas , Regulação para Baixo , Ativação Enzimática , Flavonoides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/efeitos dos fármacos , Receptores de Angiotensina/genética , Transfecção
15.
Development ; 128(1): 67-74, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11092812

RESUMO

Drosophila wings are patterned by a morphogen, Decapentaplegic (Dpp), a member of the TGFbeta superfamily, which is expressed along the anterior and posterior compartment boundary. The distribution and activity of Dpp signaling is controlled in part by the level of expression of its major type I receptor, thickveins (tkv). The level of tkv is dynamically regulated by En and Hh. We have identified a novel gene, master of thickveins (mtv), which downregulates expression of tkv in response to Hh and En. mtv expression is controlled by En and Hh, and is complementary to tkv expression. In this report, we demonstrate that mtv integrates the activities of En and Hh that shape tkv expression pattern. Thus, mtv plays a key part of regulatory mechanism that makes the activity gradient of the Dpp morphogen.


Assuntos
Proteínas de Drosophila , Drosophila/embriologia , Drosophila/fisiologia , Genes de Insetos , Proteínas de Insetos/fisiologia , Fatores de Crescimento Neural , Proteínas Serina-Treonina Quinases/fisiologia , Receptores de Superfície Celular/fisiologia , Animais , Regulação da Expressão Gênica no Desenvolvimento , Morfogênese , Fator de Crescimento Transformador beta/fisiologia , Asas de Animais/embriologia , Asas de Animais/fisiologia
16.
Circulation ; 102(15): 1834-9, 2000 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-11023940

RESUMO

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPARgamma) activators, such as troglitazone (Tro), not only improve insulin resistance but also suppress the neointimal formation after balloon injury. However, the precise mechanisms have not been determined. Angiotensin II (Ang II) plays crucial roles in the pathogenesis of atherosclerosis, hypertension, and neointimal formation after angioplasty. We examined the effect of PPARgamma activators on the expression of Ang II type 1 receptor (AT(1)-R) in cultured vascular smooth muscle cells (VSMCs). METHODS AND RESULTS: AT(1)-R mRNA and AT(1)-R protein levels were determined by Northern blot analysis and radioligand binding assay, respectively. Natural PPARgamma ligand 15-deoxy-Delta(12,14)-prostaglandin J(2), as well as Tro, reduced the AT(1)-R mRNA expression and the AT(1)-R protein level. The PPARgamma activators also reduced the calcium response of VSMCs to Ang II. PPARgamma activators suppressed the AT(1)-R promoter activity measured by luciferase assay but did not affect the AT(1)-R mRNA stability, suggesting that the suppression occurs at the transcriptional level. CONCLUSIONS: PPARgamma activators reduced the AT(1)-R expression and calcium response to Ang II in VSMCs. Downregulation of AT(1)-R may contribute to the inhibition of neointimal formation by PPARgamma activators.


Assuntos
Regulação da Expressão Gênica , Músculo Liso Vascular/metabolismo , Prostaglandina D2/análogos & derivados , Receptores de Angiotensina/genética , Receptores Citoplasmáticos e Nucleares/fisiologia , Tiazolidinedionas , Fatores de Transcrição/fisiologia , Angiotensina II/metabolismo , Animais , Cálcio/metabolismo , Células Cultivadas , Cromanos/farmacologia , Regulação para Baixo , Músculo Liso Vascular/fisiologia , Regiões Promotoras Genéticas , Prostaglandina D2/farmacologia , Estabilidade de RNA/fisiologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/metabolismo , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Tiazóis/farmacologia , Fatores de Transcrição/efeitos dos fármacos , Troglitazona
18.
Vet Pathol ; 37(2): 177-83, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10714647

RESUMO

In canine mammary tumors, we examined the telomerase activity, proliferative activity by proliferative cell nuclear antigen (PCNA) immunohistochemistry, and percentage of apoptotic cells by the deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. The relationship between these measures and histopathologic malignancy was also investigated. PCNA index was highest in malignant tumors (adenocarcinoma: 27.0%; malignant mixed tumor: 15.7%), followed by benign tumors (adenoma: 4.4%; benign mixed tumor: 5.3%), hyperplasia (2.1%), and normal mammary gland (0.9%). In adenoma and adenocarcinoma, papillary and solid types showing higher cellularity tended to have higher PCNA indices than did cystic and tubular types. Although the TUNEL index was <1% in all cases, the relationship between this measure and histopathologic diagnosis showed the same tendency as observed in PCNA immunostaining. Telomerase activity was detectable in all adenomas, benign mixed tumors, and adenocarcinomas examined. In contrast, all normal mammary glands, hyperplasias, and malignant mixed tumors were negative for telomerase. Relative telomerase activity (RTA) of adenocarcinoma (56.5) was significantly higher than that of adenoma (27.8) and benign mixed tumor (33.9), and a significant positive correlation (P < 0.001) was noted between RTA and PCNA index. No significant correlations were noted between either PCNA or TUNEL index and clinical features such as metastasis and tumor diameter. PCNA index and telomerase activity may be useful markers for judging malignancy of canine mammary tumors.


Assuntos
Adenocarcinoma/veterinária , Adenoma/veterinária , Doenças do Cão/patologia , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/patologia , Antígeno Nuclear de Célula em Proliferação/análise , Telomerase/análise , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Adenoma/enzimologia , Adenoma/patologia , Animais , Divisão Celular , Fragmentação do DNA , Primers do DNA/química , DNA de Neoplasias/química , Doenças do Cão/enzimologia , Cães , Feminino , Hiperplasia/enzimologia , Hiperplasia/patologia , Hiperplasia/veterinária , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas/veterinária , Glândulas Mamárias Animais/enzimologia , Neoplasias Mamárias Animais/química , Neoplasias Mamárias Animais/enzimologia , Reação em Cadeia da Polimerase/veterinária , Prognóstico
19.
Biochem Biophys Res Commun ; 269(3): 666-70, 2000 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-10720473

RESUMO

The biological effects of Amadori adducts that are early nonenzymatically glycated protein on vascular cells were poorly defined. We examined the effect of glycated serum albumin (GA) on the expression of monocyte chemoattractant protein-1(MCP-1) that is an important chemokine recruiting monocyte to blood vessel. GA increased MCP-1 mRNA expression with a peak after 3 h of stimulation. The induction of MCP-1 by GA was dose-dependent. The MCP-1 mRNA expression by GA was completely inhibited by PD98059 and genistein that inhibit mitogen activated protein (MAP) kinase kinase and tyrosine kinase, respectively. N-Acetylcysteine, a potent antioxidant, also suppressed the GA-induced MCP-1 expression. These results suggest that GA induces production of reactive oxygen species and activates tyrosine kinase and MAP kinase in VSMC. Activation of these signals results in MCP-1 expression. GA-induced MCP-1 expression may be one of the mechanisms by which the diabetic patients suffer from accelerated atherosclerosis.


Assuntos
Quimiocina CCL2/genética , Regulação da Expressão Gênica/fisiologia , Músculo Liso Vascular/metabolismo , Albumina Sérica/farmacologia , Animais , Aorta Torácica/metabolismo , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Produtos Finais de Glicação Avançada , Cinética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Tirosina Quinases/metabolismo , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Soroalbumina Bovina/farmacologia , Transcrição Gênica , Albumina Sérica Glicada
20.
Hypertension ; 35(1 Pt 2): 297-302, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10642314

RESUMO

All-trans retinoic acid (atRA) is a biologically active metabolite of vitamin A that plays an important role in cell differentiation and proliferation. Although neointimal formation after balloon injury of rat carotid artery is inhibited by atRA, the mechanisms are not clearly understood. Because the renin-angiotensin system is one of the crucial components of atherosclerosis, we examined the effects of atRA on the expression of angiotensin II type 1 receptor (AT(1)-R) in vascular smooth muscle cells. atRA (1 micromol/L) decreased the AT(1)-R mRNA level by 50% after 24 hours; AT(1)-R number was also reduced to the same extent after 48 hours. atRA markedly suppressed promoter activity of the AT(1)-R promoter-luciferase construct, but AT(1)-R mRNA stability was not affected. Cycloheximide blocked the atRA-induced decrease in AT(1)-R mRNA expression, suggesting that this process requires de novo protein synthesis. Simultaneous treatment with an agonist (Ro40-6055) specific for retinoic acid receptor (RAR) and an agonist (Ro25-7836) specific for retinoid X receptor (RXR) suppressed the AT(1)-R mRNA expression comparable to that with treatment with atRA, suggesting that the RAR/RXR heterodimer mediates the effect of atRA in AT(1)-R downregulation. These results suggest that atRA suppressed AT(1)-R mRNA transcription through new protein synthesis induced by RAR/RXR-dependent transcription. This study provides novel insight into a role of atRA as an important molecule that regulates AT(1)-R gene expression and provides possible mechanisms for the suppression of neointimal formation by atRA.


Assuntos
Antineoplásicos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Músculo Liso Vascular/citologia , Receptores de Angiotensina/genética , Tretinoína/farmacologia , Animais , Aorta Torácica/citologia , Benzoatos/farmacologia , Ligação Competitiva/genética , Proteína de Ligação a CREB , Células Cultivadas , Cicloeximida/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Óperon Lac , Luciferases/genética , Músculo Liso Vascular/química , Músculo Liso Vascular/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/fisiologia , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/análise , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores do Ácido Retinoico/fisiologia , Proteínas Recombinantes de Fusão/genética , Receptores X de Retinoides , Tetra-Hidronaftalenos/farmacologia , Transativadores/metabolismo , Fatores de Transcrição/fisiologia
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