Polyvalent siRNA-Gold Nanoparticle Constructs to Eradicate Glioma

描述(申请人提供)：脑瘤是最具挑战性的癌症之一。胶质母细胞瘤是最具侵袭性的脑瘤类型，尽管有药物干预，中位生存期只有12-15个月。如果肿瘤部位可以切除，手术是一种可以接受的治疗选择，但胶质母细胞瘤的浸润性往往阻碍了完全切除。放射治疗和化疗也是可行的治疗方案，但它们都受到副作用的困扰，从恶心和脱发等轻微反应到个性改变、体能丧失或认知功能障碍等极端并发症。因此，在护理方面的进步不仅是为了提高存活率，而且是为了提高治疗后的生活质量，这是非常必要的。RNA干扰(RNAi)已成为传统治疗的一种有前途的替代方法。在RNAi中，短的双链核糖核酸(RNA)序列被传递给细胞，导致编码的信使RNA被降解，从而沉默基因的表达。针对癌症的特定基因为诱导癌细胞死亡或使肿瘤对其他形式的治疗敏感提供了一种有趣的方法。不幸的是，将siRNA运送到胶质母细胞瘤和其他脑肿瘤是困难的，因为它必须首先穿过血脑屏障，进入癌细胞，然后逃离内体才能发挥作用。此外，siRNA在血液中的半衰期很短，因为它会被核糖核酸酶迅速降解。这项拟议的工作试图通过将siRNA密集地负载到金纳米粒子上来克服这些限制，从而保护它免受核糖核酸酶的降解，并使其能够穿过血脑屏障进入脑肿瘤。这些siRNA-金纳米颗粒结合物(siRNA-AuNPs)介导的RNAi的有效性将通过胶质母细胞瘤的体内模型进行评估。首先，将结合光学成像方法，通过用荧光团标记构建物来实时、高分辨率地跟踪siRNA-AuNP向肿瘤的输送。然后，系统地调整siRNA-AuNP剂量的浓度和时间，以找到最有效地沉默胶质母细胞瘤基因的方案，从而产生最长的存活时间。最后，将通过将多个siRNA序列包裹在金纳米颗粒上来研究使用单一平台沉默多个胶质母细胞瘤基因的效果。这应该会在肿瘤消退和总存活率方面产生协同改善。这些目标的成功实现将使siRNA-AuNPs成为治疗胶质母细胞瘤的传统疗法的独特、微创、安全和有效的替代方案。这项工作不仅将验证siRNA-AuNPs用于治疗胶质母细胞瘤的有效性，还将为深入了解RNAi在体内的作用提供依据。该项目的长期目标是将这一新疗法转化为治疗胶质母细胞瘤的临床试验，并将其应用于其他类型的肿瘤。 公共卫生相关性：有必要改善对胶质母细胞瘤患者的护理，不仅是为了提高存活率，也是为了改善治疗后的生活质量。这项研究将开发一种新的疗法来满足这一需求，未来可能也会扩展到其他癌症和疾病，对公共健康产生重大影响。

DESCRIPTION (provided by applicant): Brain tumors are one of the most challenging forms of cancer to treat. Glioblastoma is the most aggressive type of brain tumor and despite medical intervention the median survival is only 12-15 months. Surgery is an acceptable treatment option if the tumor location is amenable to removal, but often the infiltrative nature of glioblastoma prevents complete resection. Radiation therapy and chemotherapy are also viable treatment options, but they are plagued by side effects ranging from minor reactions like nausea and hair loss to extreme complications such as personality changes, loss of physical ability, or cognitive dysfunction. Therefore, there is a significant need for advances in care not only to improve survival but also to improve quality of life post treatment. RNA interference (RNAi) has emerged as a promising alternative to conventional therapy. In RNAi, short double-stranded ribonucleic acid (RNA) sequences delivered to a cell induce the encoded messenger RNA to be degraded, thereby silencing gene expression. Targeting genes specific to cancer offers an intriguing method for either inducing cancerous cell death or sensitizing tumors to other forms of therapy. Unfortunately, it is difficult to deliver siRNA to glioblastoma and other brain tumors because it must first cross the blood-brain barrier, enter the cancerous cells, and then escape the endosome to render its effect. In addition, siRNA has a short half-life in blood because it is rapidly degraded by RNases. The proposed work seeks to overcome these limitations by densely loading siRNA onto gold nanoparticles, thereby protecting it from RNase degradation and enabling it to cross the blood-brain barrier and enter brain tumors. The efficacy of RNAi mediated by these siRNA-gold nanoparticle conjugates (siRNA-AuNPs) will be evaluated using in vivo models of glioblastoma. First, optical imaging methods will be incorporated to track siRNA-AuNP delivery to tumors in real time and with high-resolution by labeling the constructs with fluorophores. Then, the concentration and schedule of siRNA-AuNP dosing will be systematically adjusted to find the regimen that is most effective at silencing glioblastoma genes, thereby producing the longest survival time. Finally, the effect of silencing multiple glioblastoma genes using a single platform will be studied by coating the gold nanoparticles with multiple siRNA sequences. This should yield a synergistic improvement in tumor regression and overall survival. Successful completion of these aims will render siRNA-AuNPs a unique, minimally invasive, safe, and effective alternative to conventional therapy for glioblastoma. This work will not only validate the use of siRNA-AuNPs for treatment of glioblastoma, but also provide insight into the effects of RNAi in vivo. The long-term goals of this project are to transition this novel therapy into clinical trials for glioblastoma and to expand this application o other types of neoplasia. PUBLIC HEALTH RELEVANCE: There is a significant need for improvements in care of glioblastoma patients not only to improve survival but also to improve quality of life post treatment. This research will develop a new therapy to meet this need that may be extended to other cancers and diseases in the future as well, substantially impacting public health.