胶质瘤中STAT3通路及其负调控因子PIAS3活化状态和生物学效应的分析

Activation Status and Biological Effects Analysis of STAT3 Signaling Pathway and Its Negative Regulator PIAS3 in Gliomas

目的探讨STAT3信号通路及其负调控因子PIAS3在胶质瘤细胞中的活化状态及生物学效应。方法采用免疫组织化学方法检测胶质瘤中p-STAT3及PIAS3的活化状态;STAT3通路抑制剂60μmol/L AG490作用胶质瘤U118、U87细胞24、48 h,MTT法观察U118、U87细胞增殖能力的变化;免疫荧光检测AG490作用前后细胞p-STAT3及PIAS3蛋白表达的变化。结果 pSTAT3及PIAS3在不同级别胶质瘤细胞胞质和胞核内的表达无统计学差异,但在细胞核内p-STAT3和PIAS3的表达呈负相关;AG490处理细胞后,U118细胞数量无明显改变,U87细胞则表现为生长抑制。免疫荧光结果显示,AG490处理后,U118细胞pSTAT3和PIAS3表达水平均无显著改变,U87细胞p-STAT3核内表达下调,PIAS3出现明显核易位。结论 PIAS3通过核易位调控STAT3信号通路的活性,抑制胶质瘤细胞生长。

Objective To discuss the activation and biological effects of STAT3 signaling pathway and its negative regulator PIAS3 in glioma cells. Methods Immunohistochemistry（IHC）was used to test the expression of p-STAT3 and PIAS3 in gliomas. AG490（60 μmol/L）,the inhibitor of STAT3 signaling pathway,was used to treat U118 and U87 cells for 24/48 h,and the method of MTT assay was taken to evaluate the proliferation after AG490 treatment. The expression of p-STAT3 and PIAS3 was also examined by immunofluorescence（IF）. Results There was no obvious significance between p-STAT3 and PIAS3 in nuclei or cytoplasm at different grades of gliomas. Whereas,p-STAT3 and PIAS3 were negatively correlated in the nuclei of vary grades malignancy gliomas. After AG490 treatment,U118 cells showed no obvious quantitative changes. However,U87 cells showed obvious growth inhibition. IF results showed that there was no significant change at the levels of p-STAT3 and PIAS3 after AG490 treatment in U118 cells. However,the expression of p-STAT3 in the nuclei was down-regulated,and PIAS3 showed obvious nuclear translocation in U87 cells. Conclusion Nuclear translocation of PIAS3 plays the key role in modulating JAK/STAT signaling activation and inhibiting glioma cells proliferation.