OP16联合雷帕霉素对人食管鳞癌裸鼠移植瘤生长和细胞凋亡的影响
Effects of OP16 combined with rapamycin on growth and cell apoptosis of human esophageal squamous cell carcinoma xenograft in nude mice

目的:探讨新型冬凌草甲素衍生物OP16和mTOR抑制剂雷帕霉素对人食管鳞癌裸鼠移植瘤生长和凋亡的影响及可能的分子机制。方法:建立人食管鳞癌EC9706细胞的裸鼠移植瘤模型,随机分为对照组、OP16组、雷帕霉素组和联合治疗组,每组10只。观察经过治疗后荷瘤裸鼠的肿瘤生长情况,使用TUNEL法检测各组肿瘤组织中细胞凋亡情况,并使用Western blot法检测裸鼠肿瘤组织中PI3K/Akt/mTOR通路相关蛋白的表达情况。结果:OP16和雷帕霉素单独给药均能抑制肿瘤的生长,二者联用抑制效果更为明显(FOP16=17.562,F雷帕霉素=18.302,F交互=20.716,P<0.001)。TUNEL结果表明OP16和雷帕霉素单独给药均能促进肿瘤细胞凋亡,且二者联用时促凋亡能力增强(FOP16=209.515,F雷帕霉素=230.235,F交互=445.186; P<0.001)。Western blot结果表明,OP16可以显著抑制雷帕霉素引起的PI3K/Akt负反馈激活(P<0.01),且二者联用可以协同抑制mTOR的表达及磷酸化激活(P<0.05)。结论:OP16与雷帕霉素联用具有较好的协同抑制肿瘤生长以及促进肿瘤细胞凋亡的作用,其分子机制可能与对PI3K/Akt/mTOR信号通路的抑制作用有关。
Aim: To evaluate the effects of a novel derivative of oridonin OP16 and a mTOR inhibitor rapamycin used alone or in combination on the growth and cell apoptosis of human esophageal squamous cell carcinoma xenograft in nude mice and its possible mechanisms.Methods: EC9706 cells were subcutaneously inoculated into nude mice to establish a subcutaneous transplantation tumor model. Mice were randomly allocated into control group, OP16 group, rapamycin group and combined treatment group. After treatment, the growth of xenografted tumor was observed and recorded, and the apoptosis of xenografted tumor cells was explored by TUNEL assay. Moreover, the expressions of PI3K/Akt/mTOR signaling pathway related proteins were investigated by Western blot.Results: OP16 or rapamycin alone could significantly inhibit tumor growth in xenograft mice,and the combination of them produced greater inhibition effect on tumor growth than either agent alone(FOP16=17.562,Frapamycin=18.302,Finteraction=20.716; P<0.001). The results of TUNEL assay demonstrated that OP16 and rapamycin alone could promote apoptosis of xenografted tumor cells, and the combination of them existed greater pro-apoptotic activity than either agent alone(FOP16=209.515,Frapamycin=230.235,Finteraction=445.186; P<0.001). The results of Western blot showed that OP16 could significantly inhibit rapamycin-induced PI3K/Akt activation(P<0.01), and the combination of them could synergistically inhibit the expression and phosphorylation of mTOR(P<0.05).Conclusion: The combination of OP16 and rapamycin has synergistic effects on tumor growth inhibition and cell apoptosis induction in nude mice, and the possible molecular mechanisms underlying the synergistic effect is related to the down-regulation of PI3K/Akt/mTOR signaling pathway