靶向性纳米颗粒包裹Gankyrin siRNA治疗骨肉瘤的实验研究

Osteosarcoma mainly occurs in adolescents, with the characteristics of high degree of malignancy and the tendency of pulmonary metastasis. The prognosis of osteosarcoma is always poor. Since the potential pathogenesis of osteosarcoma is not clear yet, it is of great importance to further investigate the key molecular markers prompting the tumorigenesis and development of osteosarcoma followed by efforts in establishing effective targeting therapy stratages. Our previous work have demonstrated significant increased expression of Gankyrin in osteosarcoma tissues and silencing the expression of Gankyrin with RNAi technology induced obvious apoptosis in many osteosarcoma cells. In vivo studies also confirmed that inhibiton of Gankyrin could significantly reduce tumor growth. These data strongly suggest that Gankyrin play an important role in the pathogenesis of osteosarcoma and it may be a new target molecular for osteosarcoma gene therapy. In this work, we intend to perform further systematic research to explore the regulation function and its potential related signal tranduction mechanism of Gankyrin in osteosarcoma pathogenesis. In addition, Gankyrin siRNA wrapped in the nanoparticles targeting at osteosarcoma cells would be used in in vivo experimental model to confirm the influence of down-regulation of Gankyrin expression on osteosarcoma tumorigenesis and development and to determine the potential clinical applied value of Gankyrin in osteosarcoma targeting therapy. Our work might further explore new molecluar targets in osteosarcoma pathogenesis and might also contribute to targeting therapy research.

骨肉瘤恶性程度高、好发于青少年、易发生肺部转移，预后极差。目前其发病机制尚不明确，寻找影响骨肉瘤发生发展的标志性分子，并建立针对其靶向治疗策略具有重要意义。我们前期研究发现Gankyrin在骨肉瘤组织中表达明显增高，应用RNAi技术干扰骨肉瘤细胞内Gankyrin的表达可以诱导大量骨肉瘤细胞发生凋亡，动物体内荷瘤实验也证实抑制Gankyrin可以显著降低肿瘤生长能力。这些都提示我们Gankyrin在骨肉瘤发病中具有重要作用，并可能成为潜在的治疗靶点。本项目组拟对Ganyrin在骨肉瘤发生发展中的调控作用做系统深入研究，并探讨其相关信号传导机制。在此基础上选用靶向骨肉瘤的纳米颗粒包裹针对Gankyrin的siRNA，建立系统性给予siRNA的实验模型，明确抑制Gankyrin表达对骨肉瘤发生发展的影响，确定其在骨肉瘤靶向治疗中的价值，从而为骨肉瘤发病机制研究、分子靶向治疗提供新的研究靶点。

本课题以骨肉瘤为研究对象，观察利用siRNA靶向沉默Gankyrin基因，体外和体内对骨肉瘤的生物学特性的调控作用。该研究丰富了Gankyrin RNAi基因治疗骨肉瘤的理论基础，为骨肉瘤的基因治疗提供了重要的依据。主要研究结果如下：. 1. 构建并扩增了腺病毒-Gankyrin siRNA系统，腺病毒载体系统对于骨肉瘤HOS细胞具有较高的转染效率，是以骨肉瘤细胞为靶细胞的合适基因转移载体。利用腺病毒载体实现基因干预的系统可成为进行骨肉瘤靶向基因治疗的有效技术手段之一。. 2. 与成骨细胞相比，骨肉瘤HOS细胞中的Gankyrin转录水平及蛋白表达均显著升高。课题中构建的靶向沉默Gankyrin基因腺病毒载体，通过RNAi干扰，在体外可有效抑制骨肉瘤HOS细胞中Gankyrin的转录和翻译，降低Gankyrin的表达，并对细胞的增殖、迁移及侵袭、凋亡与细胞周期等生物学特性具有有效的调控作用。. 3. 在体实验显示，经过腺病毒-Gankyrin siRNA系统沉默Gankyrin的表达，可以有效降低HOS细胞体内成瘤的生物学特性。利用骨肉瘤皮下荷瘤模型，采用瘤体周围注射靶向沉默Gankyrin基因的腺病毒载体系统，可显著抑制骨肉瘤瘤体的体积与重量，该给药系统有望成为骨肉瘤治疗的一种有效工具。. 在基金的资助下，撰写了中文论文2篇和英文论著1篇，正在投稿过程中。获军队医疗成果奖三等奖1项（2015-3-212-1）。