Tumor targeted RNAi by novel nanovectors for molecular therapy of prostate cancer

新型纳米载体肿瘤靶向RNAi用于前列腺癌的分子治疗

• 批准号: 7238432
• 负责人: Liang Xu
• 金额: $ 9.73万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7238432
• 关键词: Animal Model; Antibodies; Antisense Oligonucleotides; Apoptosis; Apoptotic; BCL-Xs protein; Biological; Cell Death; Charge; Clinical Research; Development; Double-Stranded RNA; Drug Formulations; Drug resistance; Gene Delivery; Gene Expression; Gene Silencing; Gene Targeting; Genes; Goals; Human; In Vitro; Legal patent; Ligands; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; Membrane; Molecular; Molecular Target; Nanostructures; Neoplasm Metastasis; Normal Cell; Normal tissue morphology; Nude Mice; Oncogenes; Phase I Clinical Trials; Pilot Projects; Plasmids; Prostate; Prostate Cancer therapy; Prostatic Neoplasms; Protein Overexpression; Proteins; RNA; RNA Interference; Radiation therapy; Resistance; Small Interfering RNA; Specificity; Structure; Surface; System; Testing; Therapeutic; Transferrin; Transferrin Receptor; Treatment Efficacy; United States Food and Drug Administration; Validation; Viral; Virion; Xenograft Model; anticancer research; base; cancer cell; cancer therapy; concept; design; gene therapy; human disease; improved; in vivo; knock-down; nanoparticle; nanovector; novel; novel therapeutics; receptor; size; small hairpin RNA; success; targeted delivery; therapy resistant; tool; tumor; tumor initiation; tumor progression

DESCRIPTION (provided by applicant): The potent, sequence-specific gene silencing by small interfering RNA (siRNA) has become a powerful tool in cancer research and holds significant potential as novel molecular therapy for cancer. However, delivering the siRNA-based therapeutics efficiently and specifically to prostate cancer and its metastases remains a great challenge. We have developed a tumor-specific, ligand-targeting, self-assembled DNA-nanovector system for prostate cancer gene delivery. The nanovectors show promising efficiency and specificity in targeted delivery of various genes and anti-sense oligonucleotides to human prostate cancer, with limited effect on normal tissues (US Patent No. 6,749,863). This nanovector system is now in Phase I clinical trial for non-viral p53 gene therapy. The objective of this pilot project proposal is to explore the feasibility of using our patented nanovector system for tumor-targeted delivery of siRNA-based therapeutics for human prostate cancer. In our preliminary studies, we have designed siRNAs for human Bcl-2 and Bcl-xL that can potently knock-down Bcl-2/Bcl-xL up to 95%, leading to extensive cancer cell death (US Patent pending). We propose to use Bcl-2/Bcl-xL siRNA to test two inter-related hypotheses: (1) the self-assembled nanovectors can selectively deliver siRNA to prostate cancer and efficiently silence the target Bcl-2/Bcl-xL; (2); Knock-down of the anti-apoptotic Bcl-2/Bcl-xL will induce apoptosis in human prostate cancer cells that depend on Bcl-2/Bcl-xL for survival, thus overcome resistance and restore sensitivity of prostate cancer cells to chemo/radiotherapy. Our long-term goal is to develop the tumor-targeting siRNA-nanovectors as novel molecular therapy for prostate cancer. To test our hypothesis, we propose to carry out two SPECIFIC AIMS: AIM 1: To prepare and optimize the nanovectors for efficient RNA interference for human prostate cancer in vitro and in vivo; AIM 2: To investigate anti-tumor activities and target validation of Bcl-2/Bcl-xL siRNA-nanovectors in nude mouse xenograft models of human prostate cancer with high levels of Bcl-2/Bcl-xL. Anti-apoptotic proteins Bcl-2 and Bcl-xL are overexpressed in most of prostate cancer and contribute to prostate tumor initiation, progression and resistance to therapy. Molecular modulation of Bcl-2/Bcl-xL represents a promising strategy for overcoming the resistance to apoptosis induced by current cancer therapy. Combining siRNA-based molecular therapy with conventional therapy would improve the efficacy and overcome the resistance to current cancer treatment, especially for tumor metastasis, in which Bcl-2/Bcl-xL protein is overexpressed and for which conventional therapy is not very effective. Successfully carried out, our study will provide proof-of-concept that siRNA can be delivered by the self-assembled nanovectors for tumor-targeted RNA interference of the genes critical for prostate cancer progression and resistance. Combining tumor-targeted RNA interference of Bcl-2/Bcl-xL with conventional therapy would improve the efficacy and overcome the drug resistance to current cancer treatment, especially for metastasis, in which Bcl- 2/Bcl-xL protein is overexpressed and for which conventional therapy is not very effective. Successfully carried out, our studies will provide proof-of-concept that siRNA can be delivered by the self-assembled nanovectors for tumor-targeted silencing of the genes critical for prostate tumor progression and resistance. The success of tumor-targeted RNA interference by nanovectors in vivo will have a major impact on the development of siRNA-based novel therapeutics for various molecular targets of human prostate cancer.

描述（由申请人提供）：小干扰RNA（siRNA）的有效、序列特异性基因沉默已成为癌症研究中的有力工具，并具有作为癌症新型分子疗法的巨大潜力。然而，高效、特异地针对前列腺癌及其转移瘤提供基于 siRNA 的疗法仍然是一个巨大的挑战。我们开发了一种肿瘤特异性、配体靶向、自组装 DNA 纳米载体系统，用于前列腺癌基因递送。纳米载体在将各种基因和反义寡核苷酸靶向递送至人类前列腺癌方面显示出令人鼓舞的效率和特异性，而对正常组织的影响有限（美国专利号6,749,863）。该纳米载体系统目前正处于非病毒 p53 基因治疗的 I 期临床试验中。该试点项目提案的目的是探索使用我们的专利纳米载体系统对人类前列腺癌进行基于 siRNA 的肿瘤靶向治疗的可行性。在我们的初步研究中，我们为人类 Bcl-2 和 Bcl-xL 设计了 ​​siRNA，可以有效地将 Bcl-2/Bcl-xL 敲低高达 95%，从而导致广泛的癌细胞死亡（美国专利正在申请中）。我们建议使用Bcl-2/Bcl-xL siRNA来测试两个相互关联的假设：（1）自组装纳米载体可以选择性地将siRNA递送至前列腺癌并有效沉默靶标Bcl-2/Bcl-xL； (2);敲低抗凋亡Bcl-2/Bcl-xL将诱导依赖Bcl-2/Bcl-xL生存的人前列腺癌细胞凋亡，从而克服前列腺癌细胞对化疗/放疗的耐药性并恢复敏感性。我们的长期目标是开发肿瘤靶向 siRNA 纳米载体作为前列腺癌的新型分子疗法。为了检验我们的假设，我们建议实现两个具体目标： 目标 1：制备和优化纳米载体，以在体外和体内对人类前列腺癌进行有效的 RNA 干扰；目的2：研究Bcl-2/Bcl-xL siRNA纳米载体在高水平Bcl-2/Bcl-xL的人前列腺癌裸鼠异种移植模型中的抗肿瘤活性和靶点验证。抗凋亡蛋白 Bcl-2 和 Bcl-xL 在大多数前列腺癌中过度表达，并有助于前列腺肿瘤的发生、进展和治疗耐药。 Bcl-2/Bcl-xL 的分子调节代表了克服当前癌症治疗诱导的细胞凋亡抵抗的一种有前途的策略。将基于siRNA的分子疗法与常规疗法相结合将提高疗效并克服对当前癌症治疗的耐药性，特别是对于Bcl-2/Bcl-xL蛋白过度表达且常规疗法不太有效的肿瘤转移。如果成功进行，我们的研究将提供概念证明，证明自组装纳米载体可以传递 siRNA，对前列腺癌进展和抵抗至关重要的基因进行肿瘤靶向 RNA 干扰。将Bcl-2/Bcl-xL的肿瘤靶向RNA干扰与常规疗法相结合，将提高疗效并克服目前癌症治疗的耐药性，特别是对于Bcl-2/Bcl-xL蛋白过表达且常规疗法效果不佳的转移灶。如果成功进行，我们的研究将提供概念证明，证明 siRNA 可以通过自组装纳米载体传递，用于肿瘤靶向沉默对前列腺肿瘤进展和抵抗至关重要的基因。纳米载体体内肿瘤靶向RNA干扰的成功将对针对人类前列腺癌各种分子靶点的基于siRNA的新型疗法的开发产生重大影响。