Notch信号通路联合Wnt信号通路在肾母细胞瘤发病机制中的作用

The role of Notch signaling pathway and Wnt signaling pathway in the pathogenesis of Wilm＆#39;s tumor

目的 探讨Notch信号通路联合Wnt信号通路在肾母细胞瘤发病机制中的作用.方法 收集临床上肾母细胞瘤及非瘤肾脏疾病患儿的组织标本,通过免疫组织化学及实时荧光定量聚合酶链反应（FQ-PCR）方法检测标本中Notch1及血管内皮生长因子（VEGF）的蛋白表达水平及mRNA表达水平;采用γ-内分泌酶抑制剂（DAPT）抑制的人肾母细胞瘤细胞株（SK-NEP-1）中Notch后,通过Western blot检测Notch、Jagged1、VEGF、及Wnt和β-连环蛋白（β-catenin）的蛋白表达水平.结果 免疫组织化学结果显示,肿瘤组Notch1蛋白吸光度值Ⅱ期为0.5193±0.0086,Ⅲ期为0.6168±0.0022,Ⅳ期为0.892 6±0.006 5,明显高于正常组的0.205 3±0.009 3,差异有统计学意义（P＜0.05）;VEGF的蛋白表达水平亦与肿瘤分期呈正相关.利用不同浓度的DAPT作用于SK-NEP-1后,Notch1、Jagged1蛋白表达水平下降,且Wnt信号通路中的Wnt1、β-catenin蛋白表达水平同样明显下降;并且DAPT还能抑制SK-NEP-1中的VEGF表达.结论 Notch联合Wnt信号通路在参与促进肾母细胞瘤的发生,并且与肾母细胞瘤的恶性程度明显相关.

Objective To investigate the expression of Notch signal pathway and Wnt signaling pathway in the pathogenesis of Wil＇ s tumor.Methods The samples of Wil＇ s tumor and corresponding non-tumor kidney tissues were collected.The mRNA and protein expression levels of Notchl and vascular endothelial growth factor （VEGF） were detected by real-time fluorescent quantitative polymerase chain reaction （FQ-PCR） and immunohistochemistry respectively.Human nephroblastoma cell lines （SK-NEP-1） were treated with Notch inhibitor γ-secretase Inhibitor （DAPT）,and the signal pathways of Wnt and Notch were detected by Western blotting.Results Immunohistochemistry staining revealed that Notchl protein expression in WT group with stages of 2,3 and 4 was 0.519 3 ± 0.008 6,0.616 8 ±0.002 2,and 0.892 6 ±0.006 0respectively,which was significantly higher than in the control group （0.205 3 ±0.009 3,P 〈0.05）.The mRNA expression of Notch1 and VEGF was higher in the observation group than that in the control group.After treatment of SK-NEP-1 cells with different concentrations of DAPT,the Notch1 and Jagged1 protein expression was significantly decreased as compared with ths in the control group,and the Wnt1 and β-catenin protein expression levels were also reduced apparently,and VEGF expression also significantly decreased.Conclusion Notch and Wnt signaling pathways participate in promoting the occurrence of Wil＇s tumor,and up-regulated Notch and Wnt protein levels may be associated with malignant degree of Wil＇s tumor.