Survivin-shRNA对裸鼠骨肉瘤生长的抑制作用及其机制

目的:研究Survivin-shRNA对裸鼠骨肉瘤生长的抑制作用，并探讨其与凋亡及PI3K/Akt信号通路之间的关系。方法:重组腺病毒Survivin-shRNA转染骨肉瘤MG-63细胞，以1∶5比例进行传代，挑选稳定转染的MG-63细胞并扩增，GFP组和CON组为阴性对照组。采用皮下异种移植法构建裸鼠骨肉瘤模型50只，每3天用卡尺测量肿瘤体积；颈椎脱臼法处死裸鼠，称取骨肉瘤标本的重量；免疫组织化学法检测磷酸化Akt（p-Akt）、生存素（Survivin)、半胱氨酸天冬氨酸蛋白酶-3（Caspase-3）蛋白的表达。结果:骨肉瘤生长曲线显示，与CON组和GFP组相比，Survivin-shRNA组的肿瘤增长缓慢,差异有统计学意义（P＜0.05）；肿瘤的重量结果显示， CON组、GFP组及Survivin-shRNA组分别为（2.13±0.32） g、（1.94±0.27） g及（1.42±0.19） g，差异有统计学意义（P＜0.01）；免疫组织化学结果显示，p-Akt及Survivin的表达在Survivin-shRNA组中明显低于CON组和GFP组，差异有统计学意义（P＜0.05），而Caspase-3高表达。结论:Survivin-shRNA可抑制裸鼠骨肉瘤的生长，其机制可能是通过调节PI3K/Akt信号通路及Survivin、Caspase-3的表达来实现。

The antitumor effect and its mechanism of Survivin-shRNA on osteosarcoma in nude mice

Objective:To explore the effects and molecular mechanisms of Survivin-shRNA on tumorigenicity of MG-63 cell.Methods:Subcutaneous xenograft tumor model was established.MG-63 cells were cultured in DMEM medium and recombinant adenovirus vector survivin-shRNA and negative control rAd5-GFP were transfected into MG-63 cells.Cells were subcultured at a 1∶5 dilution.Positive stable transfectants were selected and expanded for further study.The clone in which the rAd5-Survivin-shRNA virus vectors transfected was named as survivin-shRNA group,the negative control vectors transfected was named as GFP group and MG-63 cells were named as CON group.The tumor volume every three days was measured with a caliper.Immunohistochemistry was used to determine the protein expression level of p-Akt,Survivin and Caspase-3.Results:Tumors in Survivin-shRNA group grew substantially slow compared with the CON group and GFP group,and the difference was statistically significant in the three groups（P＜0.05）.When the tumors were harvested,the average weight of tumors in Survivin-shRNA group was significantly lower than CON group and GFP group,and the difference was statistically significant in the three groups（P＜0.01）.Compared with the GFP group and CON group,the protein expression level of p-Akt and Survivin was decreased,while Caspase-3 expression was increased in Survivin-shRNA group（P＜0.05）.Conclusion:Survivin-shRNA effectively decreases the tumorigenicity of MG-63 cell.The molecular mechanisms may be achieved through regulating PI3K/Akt pathway or the expression of Survivin and Caspase-3.