Role Of PEDF In Neuroblastic Differentiation And Survival Analysis Combined With Clinical Data

Objective: ①To investigate the expression of PEDF (pigment epithelium derived factor) in neuroblastic tumors(neuroblastoma,ganglioneuroblastoma, and ganglioneuroma),and further to assess its role in enhancing neuroblastic cell differentiation.②To explore the independent prognostic factors in neuroblastic tumors, and further to establish a new neuroblastoma risk grouping. Methods: ① Basical experiment: Immunohistochemical staining for PEDF was performed on 23 neuroblastomas,17ganlioneuroblastomas and 18 ganglioneuromas. Then,every immunostained slide was analyzed via micro-digital analysis system. The statistical parameter was ISS (immunostaining score). ISS was determined by the following formula: ISS =number of pixels stained positive x pixel intensity / total number of pixels per image. In addition, the PEDF expression was measured in 4 neuroblastomas and 3 ganglioneuroblastomas by Western Blotting. The expression of β - actin was used to control the protein level. The ratio of PEDF/actin was regarded as analysis index. Kruskal-Wallis test and Nemenyi test were used to assess the ISS of three groups. Correlation between PEDF expression and maturity of neuroblastic tumors was analyzed by Spearman correlation test. The ratio of PEDF/actin in neuroblastoma and ganlioneuroblastoma was analyzed by T test.②Survival analysis of clinical data: The clinical data, including sex, age, INSS, pathological type, blood NSE, blood LDH and urine VMA of 24h, were analysed in 23 NB and 17 GNB .To investigate independent prognostic factors ,we used multi-variate analysis with Cox regression model. Based on independent prognostic factors ,PI(Prognostic Index) was determined by following formula:...