人脑胶质瘤组织高表达nNav1.5促进肿瘤细胞的迁移和侵袭

Nav1.5 is highly expressed in human glioma and promotes glioma cell migration and invasion

目的：观察电压-门控钠离子通道（voltage-gated sodium channel,VGSC）亚型nNav1.5在人脑胶质瘤组织中的表达,并探讨其对脑胶质瘤U251细胞迁移及侵袭的影响。方法：收集中国医科大学附属第一医院神经外科于2011年10月至2012年10月手术切除并经病理证实的脑胶质瘤组织标本68例,应用免疫组织化学S-P法检测脑胶质瘤组织中nNav1.5的表达。设计并化学合成nNav1.5基因特异性小干扰RNA（nNav1.5-siRNA）,用脂质体介导转染胶质瘤U251细胞,应用Real-time PCR和Western blotting法分别检测U251细胞中nNav1.5 mRNA和蛋白的表达水平,并采用细胞划痕实验和Transwell侵袭实验检测U251细胞迁移和侵袭能力的变化。结果：nNav1.5在人脑胶质瘤组织中表达的阳性率显著高于正常组织（72.6%vs23.0%,P〈0.01）,并且其在高级别胶质瘤（WHOⅢ~Ⅳ级）组织中的阳性率明显高于低级别胶质瘤（WHOⅠ~Ⅱ级）组织（85.8%vs 52.9%,P〈0.01）。nNav1.5-siRNA转染可显著抑制U251细胞中nNav1.5 mRNA和蛋白的表达（P〈0.01）;转染后U251细胞的迁移距离明显小于未转染细胞[（0.019±0.015）vs（0.223±0.031）mm,P〈0.01],且其侵袭指数明显低于未转染细胞[（2.99±0.15）%vs（6.77±0.26）%,P〈0.01]。结论：nNav1.5在人脑胶质瘤组织中高表达,干扰nNav1.5表达可显著抑制胶质瘤细胞的迁移和侵袭能力,nNav1.5是胶质瘤恶性侵袭的调控因子并有望成为胶质瘤的新标志物和治疗靶点。

Objective： To investigate the expression of voltage-gated sodium channels（ VGSCs） alpha subunit,neonatal Nav1. 5（ nNav1. 5）,in association with human glioma cell migration and invasion. Methods： Biopsy tumor specimens were collected from 68 patients who were diagnosed with glioma in China Medical University Hospital. Human glioma U251 cells were transfected transiently with an expression vector encoding nNav1. 5. The mRNA abundance and protein content of nNav1. 5 in both biopsy specimens and transfected U251 cells were assessed by real-time PCR and Western blotting respectively. The metastasis and invasion capacities of transfected U251 cells were assessed by wound healing assay and transwell invasion assay,respectively. Results： Neonatal Nav1. 5 was positive in 72. 6% of human glioma tissue specimens but only in 23. 0% of normal tissue specimens（ P 0. 01）. The expression of nNav1. 5 was positively associated with the severity of glioma; 85. 8% of WHO grade Ⅲ-Ⅳ gliomas were nNav1. 5-positive and 52. 9% of WHO gradeⅠ-Ⅱ gliomas were nNav1. 5-positive（ P 0. 01）. Neonatal Nav1. 5 silencing resulted in robust decreases in nNav1. 5mRNA and protein in U251 cells and significant inhibition of U251 migration and invasion. Conclusion： Neonatal Nav1.5 is highly expressed in human glioma where it promotes glioma cell invasion and migration. Our findings suggest that nNav1. 5 may serve as a novel diagnostic marker and /or therapeutic target for human glioma.