大黄素诱导裸鼠体内白血病K562细胞凋亡过程中PI3K/AKT通路相关分子表达的变化  

Changes of moleculars involved in PI3K/AKT pathway in emodin-induced apoptosis of human leukemia K562 cells in nude mice

作　　者：王春光[1] 刘北忠[2] 曾丽[1] 刘永立[1] 刘俊霞[1] 刘谢添[1] 王维[1] 

机构地区：[1]重庆医科大学附属永川医院肿瘤科,永川402160 [2]重庆医科大学医学检验系临床检验诊断学教育部重点实验室,重庆400016

出　　处：《肿瘤》2011年第7期573-579,共7页Tumor

基　　金：国家自然科学基金资助项目(编号:30300449);国家中医药管理局中医药科学技术研究专项课题计划项目(编号:02-03ZP52);重庆医科大学附属永川医院资助项目(编号:YJQN2011032)

摘　　要：目的:观察大黄素作用后裸鼠体内白血病K562细胞PI3K/AKT信号通路的分子变化,以探讨大黄素是否依赖PI3K/AKT信号通路参与K562细胞凋亡发生。方法:建立裸鼠K562细胞皮下移植瘤模型,腹腔连续给药12d后,处死裸鼠,称取瘤体质量,计算抑瘤率。采用HE染色和透射电子显微镜观察肿瘤细胞的凋亡情况。应用RT-PCR法检测肿瘤组织中PI3K、AKT和FoxO3a的mRNA表达水平。蛋白质印迹法检测肿瘤组织中PI3K、AKT和FoxO3a蛋白的表达水平。结果:低、中、高剂量组大黄素作用后肿瘤相对体积(V/V0)分别为8.90±0.24、5.62±0.17和2.06±0.31,与0.9%氯化钠溶液对照组(V/V0为11.83±0.47)相比,大黄素处理组的肿瘤体积明显缩小,差异具有统计学意义(P<0.01)。光学显微镜和电子显微镜观察发现,大黄素能够诱导K562细胞发生明显的凋亡。RT-PCR结果表明,不同剂量的大黄素能够引起PI3K和AKT mRNA的表达下调,而FoxO3a mRNA表达上调,且有剂量依赖性。蛋白质印迹法结果表明,大黄素处理组移植瘤组织中PI3K、AKT蛋白表达水平明显降低,而FoxO3a蛋白水平明显升高。结论:大黄素能够明显抑制人白血病K562细胞裸鼠移植瘤的生长,其机制可能与其抑制PI3K/AKT信号转导通路有关。To observe emodin-induced molecular changes in PI3K/AKT signaling pathway in human leukemia K562 cells transplanted into BALB/c nude mice, and to explore whether emodin induces the apoptosis of K562 cells through PI3K/AKT signaling pathway. Methods： The subcutaneously transplanted tumor model of human K562 cells in nude mice was established. After continuously intraperitoneal injection with different doses of emodin for 12 d, the mice were sacrificed. Then the tumor weight and volume were measured, and the tumor inhibition rate was calculated. Emodin- induced apoptotic morphological changes of K562 cells were detected by HE stain and scanning electron microscopy. RT-PCR and Western blotting were used to detect the expressions of PI3K, AKT and FoxO3a mRNAs and proteins, respectively. Results： The relative tumor volumes （V/Vo） were significantly smaller in the lowmoderate and high-dose emodin-treated groups （8.90~0.24, 5.62_＋0.17 and 2.06_＋0.31, respectively） than that in the untreated group （11.83＋0.47; P〈0.01）. Significant apoptosis of K562 cells was found in emodin-treated groups under a light microscope and an electron microscope. RT-PCR revealed down-regulation of PI3K and AKT mRNAs expression and up-regulation of FoxO3a mRNA expression induced by different concentrations of emodin in a dose-dependent manner. Western blotting analysis showed that the expression levels of PI3K and AKT proteins were markedly decreased and the expression level of FoxO3a protein was significantly elevated in xenografted tumors treated with emodin. Conclusion： Emodin can significantly inhibit the growth of K562 cell xenografts in nude mice. The underlying mechanism may be associated with inhibition of PI3K/AKT signaling pathway.

关 键 词：白血病 实验性 大黄素 异种移植模型抗肿瘤试验 细胞凋亡 基因表达 小鼠 近交BALB C K562细胞 PI3K/AKT信号转导通路 

分 类 号：R733.7[医药卫生—肿瘤]