RESUMEN
Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies in humans, and its prognosis is generally poor even after surgery. Many advances have been made to understand the pathogenesis of PDA; however, the molecular mechanisms that lead to pancreatic carcinogenesis are still not clearly understood. The aims of this study were to investigate the relationship between DLC-1 methylation status and clinicopathological characteristics of PDA patients and evaluate the role of DLC-1 methylation status in PDA. The expression of DLC-1 mRNA in PDA tissues was analyzed by real-time PCR. The methylation status of DLC-1 was analyzed by methylation-specific polymerase chain reaction (MSP). Furthermore, we determined the prognostic importance of DLC-1 methylation status in PDA patients. Our results showed that the expression level of DLC-1 mRNA in PDA tissues was lower than that in non-cancerous tissues. The rate of DLC-1 promoter methylation was significantly higher in PDA tissues than in adjacent non-cancerous tissues (p < 0.001). Downregulation of DLC-1 was strongly correlated with promoter methylation (P = 0.003). The presence of DLC-1 methylation in PDA tissue samples was significantly correlated with clinical stage (P = 0.005), histological differentiation (P = 0.05), and lymph node metastasis (P = 0.006). Kaplan-Meier survival analysis showed that DLC-1 methylation status was inversely correlated with overall survival of the PDA patients. Further, Cox multivariate analysis indicated that DLC-1 methylation status was an independent prognostic factor for the overall survival rate of PDA patients. In conclusion, our data suggest that downregulation of DLC-1 may be explained by DNA methylation; DLC-1 may be a biomarker for PDA.
Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma Ductal Pancreático/genética , Proteínas Activadoras de GTPasa/genética , Neoplasias Pancreáticas/genética , Proteínas Supresoras de Tumor/genética , Adulto , Anciano , Biomarcadores de Tumor/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/mortalidad , Metilación de ADN , Regulación hacia Abajo , Femenino , Proteínas Activadoras de GTPasa/metabolismo , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Páncreas/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidad , Pronóstico , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
The aim of this study was to investigate the expression and prognostic significance of NEDD9 in pancreatic ductal adenocarcinoma (PDA). Expressional levels of NEDD9 mRNA and protein in paired pancreatic cancer lesions and adjacent noncancerous tissues were examined by quantitative real-time PCR and western blotting. NEDD9 expression was analyzed by immunohistochemistry in 106 patients with PDA. The correlations between NEDD9 immunostaining levels and clinicopathologic factors, as well as the follow-up data of patients, were analyzed statistically. NEDD9 protein and mRNA levels were elevated in pancreatic carcinoma lesions compared with the paired adjacent noncancerous tissues. A high level of expression of NEDD9 was significantly correlated with clinical staging (P < 0.001), lymph node metastasis (P < 0.001), and histological differentiation (P < 0.001). Patients with a higher NEDD9 expression had a significantly shorter survival time than those patients with lower NEDD9 expression. The multivariate analysis revealed that NEDD9 could serve as an independent factor of poor prognosis. Our finding indicates that NEDD9 could be used as prognostic molecular marker and therapeutic target for PDA.