中文摘要：

目的：探讨Gab2-Akt-ARK5通路在胶质瘤侵袭中的意义。方法：采用免疫组织化学SP法检测90例胶质瘤组织中ARK5及Gab2表达。采用小RNA干扰转染LN-229细胞株，Western Blot检测瞬时转染后ARK5及Gab2表达。体外侵袭实验检测转染后侵袭能力变化及Western Blot检测Gab2下降后Akt和ARK5的磷酸化。结果：胶质瘤组织中ARK5和Gab2免疫组织化学阳性结果呈正相关且在高级别胶质瘤（WHO分级为Ⅲ、Ⅳ级）中表达明显高于低级别胶质瘤（WHO分级为Ⅰ、Ⅱ级）。转染ARK5、Gab2、ARK5-Gab2及SCR质粒的LN-229细胞分别称siARK5/LN-229、siGab2/LN-229、siARK5-siGab2/LN-229和SCR/LN-229。其中siARK5干扰效率为70%，siGab2的干扰效率为75%。转染后，与SCR/LN-229相比，siARK5/LN-229中ARK5表达降低， siGab2/LN-229中Gab2表达降低，siARK5-siGab2/LN-229中ARK5和Gab2表达均降低。siARK5/LN-229和siGab2/LN-229侵袭并穿透Matrigel膜基质的细胞数均比对照组少（P〈0.01），且siARK5-siGab2/LN-229细胞数减少更显著（P〈0.01）。在IGF-1刺激下，siGab2/LN-229中Akt和ARK5的磷酸化减弱。结论：应用小RNA干扰技术降低ARK5或Gab2表达使LN-229细胞侵袭转移能力降低，同时Gab2表达降低抑制ARK5和Akt磷酸化，提示Gab2-Akt-ARK5通路参与胶质瘤细胞的侵袭。

英文摘要：

Objective：This study aimed to investigate the effect and significance of a binding protein-2 （Gab2）-Akt-ARK5 signaling pathway on the invasion of glioma cells. Methods：Immunohistochemical methods were used to detect the expressions of Gab2 and ARK5 in 45 cases of glioma tissue. siRNA plasmid was used to transfect LN-229 cells, and western blot was performed to analyze the protein expressions of Gab2 and ARK5. In vitro Matrigel invasion assay was conducted to detect variations in the invasiveness of transfected cells. Western blot was also conducted to analyze the protein phosphorylation of Akt and ARK5 in the cells transfected with Gab2 plasmid. Results：Immunohistochemical assay revealed that the expressions of ARK5 and Gab2 in glioma cells were positively correlated, and both expressions were higher in high-grade glioma （WHO gradeⅢ,Ⅳ） than in low-grade glioma （WHO gradeⅠ,Ⅱ）. LN-229 cells transfected with ARK5 plasmid, Gab2 plasmid, ARK5 and Gab2 plasmid, and control plasmid were named siARK5/LN-229, siGab2/LN-229, siARK5 and siGab2/LN-229, and SCR/LN-229, respectively. After transfection was performed, the protein expressions of ARK5 and Gab2 were respectively decreased in siARK5/LN-229 and siGab2/LN-229. The protein expressions of ARK5 and Gab2 in siARK5 and siGab2/LN-229 were also respectively decreased. After ARK5 or Gab2 was downregulated, the number of glioma cells, which invaded and penetrated Matrigel, was decreased （P〈0.01）. The number of glioma cells also decreased significantly after ARK5 and Gab2 were downregulated. The phosphorylation of Akt and ARK5 in siGab2/LN-229 cells was decreased after these cells were stimulated by insulin-like growth factor-1. Conclusion：The silencing of ARK5 or Gab2 impaired glioma cell invasiveness. The decreased protein expression of Gab2 inhibited the phosphorylation of Akt and ARK5. These results suggested that the Gab2-Akt-ARK5 signaling pathway could be relevantly involved in glioma cell invasion.