Polyvalent siRNA-Gold Nanoparticle Constructs to Eradicate Glioma

描述（由申请人提供）：脑肿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肿瘤类型，尽管有医学干预，其中位生存期只有12-15个月。如果肿瘤位置适合切除，手术是一种可接受的治疗选择，但胶质母细胞瘤的浸润性往往阻止完全切除。放射治疗和化疗也是可行的治疗选择，但它们的副作用很大，从恶心和脱发等轻微反应到人格改变、身体能力丧失或认知功能障碍等极端并发症。因此，迫切需要在护理方面取得进展，不仅要提高生存率，还要提高治疗后的生活质量。RNA干扰（RNAi）已成为一种有前途的替代传统治疗方法。在RNAi中，短的双链核糖核酸（RNA）序列传递到细胞中，诱导编码的信使RNA被降解，从而沉默基因表达。靶向癌症特异性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，由于siRNA必须首先穿过血脑屏障，进入癌细胞，然后逃离核内体才能发挥作用，因此很难将siRNA运送到胶质母细胞瘤和其他脑肿瘤中。此外，siRNA在血液中的半衰期很短，因为它能被rna酶迅速降解。这项工作旨在通过将siRNA密集地装载到金纳米颗粒上来克服这些限制，从而保护siRNA免受rna酶的降解，并使其能够穿过血脑屏障进入脑肿瘤。这些sirna -金纳米颗粒偶联物（siRNA-AuNPs）介导的RNAi的功效将在胶质母细胞瘤的体内模型中进行评估。首先，将采用光学成像方法，通过荧光团标记构建物，实时和高分辨率地跟踪siRNA-AuNP向肿瘤的传递。然后，系统地调整siRNA-AuNP给药的浓度和时间表，找到最有效地沉默胶质母细胞瘤基因的方案，从而产生最长的生存时间。最后，我们将通过在金纳米颗粒上包裹多个siRNA序列，研究在单一平台上沉默多个胶质母细胞瘤基因的效果。这应该在肿瘤消退和总体生存方面产生协同改善。这些目标的成功完成将使siRNA-AuNPs成为胶质母细胞瘤常规治疗的独特、微创、安全、有效的替代疗法。这项工作不仅将验证使用siRNA-AuNPs治疗胶质母细胞瘤，而且还将深入了解RNAi在体内的作用。该项目的长期目标是将这种新疗法转化为胶质母细胞瘤的临床试验，并将其应用于其他类型的肿瘤。

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.