目的 探讨南方红豆杉水提物抑制PI3K/AKT信号通路相关靶点蛋白调控裸鼠HER2阳性胃癌移植瘤生长及其机制.方法 建立荷瘤模型鼠,将80只BALB/c裸鼠接种人HER2阳性胃癌NCI-N87细胞株并采用随机数字表法分组给药及取瘤,采用Western blot法检测PI3K、pAKT、mTOR蛋白表达情况,实时荧光定量PCR法检测PI3K、AKT1、mTOR mRNA表达水平.结果Western blot法检测PI3K、pAKT、mTOR蛋白,红豆杉中、低剂量组下调PI3K蛋白表达更显著[(0.9123±0.0480)、(1.1440±0.1663)比(1.4160±0.0730),P均＜0.01],红豆杉各剂量联合赫赛汀后明显下调pAKT蛋白表达[(0.9401±0.0521)、(0.7899±0.0711)、(0.8313±0.0414)比(1.1988±0.2667),P＜0.05或P＜0.01],红豆杉高、低剂量下调mTOR蛋白表达[(1.0219±0.1769)、(1.0180±0.1290)比(1.3349±0.2045),P均＜0.01],联合赫赛汀后下调更明显[(0.7236±0.1709)、(0.8217±0.1262)、(0.8220±0.0809)比(1.3349±0.2045),P均＜0.01].实时荧光定量PCR法检测结果显示,红豆杉低剂量组PI3K mRNA表达降低[(0.6906±0.0710)比(0.9018±0.0696),P＜0.05],红豆杉各剂量组联合赫赛汀后明显下调AKT1 mRNA表达[(0.6337±0.2248)、(0.5666±0.1758)、(0.7192±0.1219)比(1.0020±0.0773),P均＜0.01],红豆杉中、低剂量组mTOR mRNA表达显著降低[(0.8183±0.0664)、(0.7917±0.0699)比(1.0004±0.1182),P均＜0.05].结论 南方红豆杉水提物可部分下调PI3K、pAKT、mTOR蛋白及PI3K、AKT1、mTOR mRNA表达水平,联合赫赛汀可增强其抑制作用.%Objective To explore the mechanism of aqueous extract of Taxus chinensis var.mairei regulating the growth of HER2-positive gastric cancer xenografts in nude mice through PI3 K/AKT/mTOR signaling pathway-related target proteins. Methods First, the tumor-bearing model mice were established. Then, 80 nude mice were inoculated with human HER2-positive gastric cancer NCI-N87 cell line and were randomly divided into different groups by random number table method, and performed drug administration and tumor collection. Western blot was used to detect the PI3 K, pAKT and mTOR expression. Real-time fluorescence quantitative PCR was used to detect PI3 K, AKT1 and mTOR mRNA expression. Results Western blotting showed that PI3 K protein expression in the medium and low dose of Taxus chinensis groups was down-regulated significantly [ (0.9123±0.0480), (1.1440±0.1663) vs (1.4160±0.0730), P＜0.01]. Different dose groups combined with Herceptin down-regulated the pAKT expression significantly[ (0.9401±0.0521), (0.7899±0.0711), (0.8313±0.0414) and (0.7219±0.0100) vs (1.1988±0.2667), P＜0.05 or P＜0.01]. In the high and low dose groups, mTOR expression also down-regulated significantly [ (1.0219±0.1769) and (1.0180±0.1290) vs (1.3349±0.2045), P＜0.01], especially when treating combined with Herceptin [ (0.7236±0.1709), (0.8217±0.1262) and (0.8220±0.0809) vs (1.3349±0.2045), P＜0.01]. Real-time fluorescence quantitative PCR revealed that PI3 K mRNA level in the low dose group decreased significantly [ (0.6906±0.0710) vs (0.9018±0.0696), P＜0.05]. Different dose groups combined with Herceptin down-regulated AKT1 mRNA expression significantly[ (0.6337±0.2248), (0.5666±0.1758) and (0.7192±0.1219) vs (1.0020±0.0773), P＜0.01]. In the medium and low dose groups, mTOR mRNA level decreased significantly [ (0.8183±0.0664) and (0.7917±0.0699) vs (1.0004±0.1182), P＜0.05]. Conclusion Aqueous extract of Taxus chinensis var.mairei could down-regulate the PI3 K/AKT/mTOR protein expression and the PI3 K/pAKT/mTOR mRNA expression partially, and the effect could be enhanced when combined with Herceptin.
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