中文摘要：

目的探讨瞬时受体电位阳离子通道1（TRPCI）是否参与缺氧诱导的胶质瘤细胞血管内皮生长因子（VEGF）表达。方法通过RT-PCR和钙图检测技术观察U87细胞上表达的TRPC亚型；采用RNAi技术、real-timeRT-PCR、免疫印迹和ELISA方法，在基因和外分泌蛋白水平观察TRPCI对缺氧U87细胞VEGF表达的影响。结果U87胶质瘤细胞表达TRPCI，TRPC3，TRPC4和TRPC5亚型。TRPC通道激动剂OAG增加了胞内Ca^2＋浓度，而TRPC通道阻断剂2-APB可抑制激动剂诱导的胞内Ca^2＋浓度增加。化学合成的siRNA-1,siRNA-2和siRNA-3分别减少TRPCI mRNA到64％，39％和36％（P〈0．01）；分别减少TRPCI蛋白到48％。29％和33％（P〈0．01）。siRNA-2和siRNA-3显著抑制了缺氧诱导的VEGF基因上调（P〈0．01）。同时缺氧U87细胞VEGF蛋白的分泌亦受到抑制（P〈0．01）。结论U87胶质瘤细胞表达功能性的TRPC通道，TRPCI参与缺氧诱导的胶质瘤VEGF表达。

英文摘要：

Objective To investigate whether TRPC1 was involved in VEGF expression induced by hypoxia in U87 MG cells. Methods RT-PCR and calcium image technique were used to observe the TRPC subtypes existed in U87 cells. RNAi, real-time RT-PCR, western blot and ELISA technique were used to observe effects of TRPC1 on hypoxia- induced VEGF gene expression and secretion. Results TRPC1, TRPC3, TRPC4 and TRPC5 were found expressed in U87 cell. Calcium concentration of U-87 cells was increased by OAG （agonist of TRPC）, OAG-induced calcium con- centration rise was attenuated by 2-APB （antagonist of TRPC）. TRPC1 mRNA were reduced to 64%, 39% and 36% respectively by the chemical synthesis of siRNA-1, siRNA-2, siRNA-3 （P 〈 0.01）; TRPC1 protein were reduced to 48%, 29%, 33% respectively by the chemical synthesis of siRNA-1, siRNA-2, siRNA-3 （P 〈 0.01）. Hypoxia en- hanced VEGF gene up-regulation was restrained by siRNA-2 and siRNA-3 （P 〈 0.01）; VEGF gene expression in Hypoxia U87 cell was restrained too （P 〈 0,01）. Conclusion U87 glioma cells express the functional TRPC channels; TRPC1 participates the VEGF expression induced by hypoxia.