RESUMO
The purpose of this study was to investigate the hypothesis that electrical stimulation regulates the levels of gene expression related to apoptosis in denervated muscle and prevents muscle atrophy after denervation.Nineteen rats were used in this study. To denervate soleus muscle, sciatic nerve was resected under aseptic condition. Electrical stimulation with 4 mA rectangular pulses of 0.5 ms duration at 2 Hz lasting for 1 hour was delivered to lower limb including the soleus muscle using two surface electrodes. After the stimulation periods of 4 weeks, the levels of gene expression related to apoptosis were evaluated. Electrical stimulation increased valosin-containing protein (VCP) expression and decreased cleaved caspase-12 expression in denervated muscles. These results indicated that electrical stimulation to denervated muscle suppresses ER-specific apoptosis by enhancing VCP expression. We proposed that electrical stimulation would be a potential treatment for preventing atrophy of denervated skeletal muscles.
Assuntos
Adenosina Trifosfatases/metabolismo , Apoptose , Caspase 12/metabolismo , Proteínas de Ciclo Celular/metabolismo , Estimulação Elétrica , Denervação Muscular/reabilitação , Músculo Esquelético/fisiopatologia , Adenosina Trifosfatases/genética , Animais , Western Blotting , Caspase 12/genética , Proteínas de Ciclo Celular/genética , Modelos Animais de Doenças , Estimulação Elétrica/métodos , Feminino , Imuno-Histoquímica , Extremidade Inferior/inervação , Extremidade Inferior/fisiopatologia , Denervação Muscular/métodos , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Nervo Isquiático/lesões , Fatores de Tempo , Resultado do Tratamento , Proteína com ValosinaRESUMO
CONCLUSIONS: The inducible nitric oxide synthase (iNOS) expression leading to vascular endothelial growth factor (VEGF) overexpression may be useful as a factor for predicting recurrence after initial treatment and prognosis in laryngeal squamous cell carcinoma (SCC). OBJECTIVE: We analyzed expression of iNOS, p53, and VEGF in various laryngeal lesions. MATERIALS AND METHODS: The study samples consisted of 63 SCC, 20 dysplasia, 7 polyp, and 5 normal epithelium of the larynx. The expression of iNOS, p53, and VEGF was identified by immunohistological methods. RESULTS: No positive immunostaining for iNOS, p53, and VEGF was observed in normal epithelium and polyps. In contrast, with the progression from mild/moderate dysplasia to severe dysplasia to carcinoma, their expression levels increased. In dysplasia, there was a significant positive correlation among expression of iNOS, p53, and VEGF. In SCC, iNOS expression correlated with VEGF overexpression and microvessel density, but not with p53 overexpression. In SCC, the expression of iNOS and VEGF significantly increased in patients who developed local recurrence and/or metastases after initial treatments. Kaplan-Meier analysis showed that disease-free survival was significantly shorter in patients with iNOS or VEGF expression. Multivariate analysis showed expression of iNOS and VEGF as independent indicators for poor disease-free survival.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Laríngeas/metabolismo , Neovascularização Patológica/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Laríngeas/mortalidade , Neoplasias Laríngeas/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/metabolismo , Lesões Pré-Cancerosas/metabolismo , Prognóstico , Proteína Supressora de Tumor p53/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
We have investigated the role of antigen-processing machinery (APM) component defects in HLA class I antigen down-regulation in laryngeal squamous cell carcinoma (SCC) lesions and assessed the clinical significance of these defects. To this end, 63 formalin-fixed, paraffin-embedded tumor lesions were examined for APM component and HLA class I antigen expression by immunohistochemistry. Calnexin, calreticulin, and ERp57 were down-regulated in approximately 25% of the lesions tested, whereas LMP2, TAP1, tapasin, and HLA class I antigens were down-regulated in at least 70% of the lesions tested. LMP2 and tapasin expression was significantly correlated with HLA class I antigen expression suggesting APM component defects as a mechanism underlying HLA class I antigen down-regulation in laryngeal SCC lesions. The expression of most APM components and HLA class I antigens was correlated with the extent of CD8+ T cell infiltration into tumor lesions. Furthermore, LMP2 and HLA class I antigen down-regulation and low CD8+ T cell infiltration were significantly associated with reduced patients' survival. Multivariate analysis identified HLA class I antigen down-regulation as an independent unfavorable prognostic marker. This association is likely to reflect the reduction in the extent of CD8+ T cell infiltration in laryngeal SCC lesions.
