Expressing New Tumor Antigens by Inhibition of Nonsense Mediated mRNA Decay

通过抑制无义介导的 mRNA 衰变表达新的肿瘤抗原

基本信息

批准号：
8610902
负责人：
Eli Gilboa
金额：
$ 30.8万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-01 至 2016-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8610902
关键词：
Address Adjuvant Antibodies Antigens Binding Biological Availability Breast Cancer Model Breast Carcinoma Cancer Patient Cancer Vaccines Cells Chemicals Clinical Colon Carcinoma Development Dose Drug Kinetics Epitopes Frequencies Glutamate Carboxypeptidase II Goals Gold Granulocyte-Macrophage Colony-Stimulating Factor Guidelines Human IL2RA gene Immune Immune response Immune system Immunity In Situ In Vitro Injection of therapeutic agent Lesion Ligands Mediating Messenger RNA Modality Modeling Mus Nature Neoplasm Metastasis Nonsense Codon Normal tissue morphology Oligonucleotides Peptides Physiological Process Protocols documentation Rattus Reagent Regulatory T-Lymphocyte Role Site Small Interfering RNA Technology Testing Tumor Antigens Tumor Immunity Vaccination aptamer base cost effective immunogenicity lung melanoma mRNA Decay mRNA Expression mRNA Surveillance neoplastic cell novel novel strategies pathogen pre-clinical prevent public health relevance subcutaneous tumor tumor growth tumor progression uptake

项目摘要

DESCRIPTION (provided by applicant): The main reason why tumors are not controlled by the immune system of the cancer patient is that, unlike pathogens, tumors do not express potent tumor antigens that can be recognized by the immune system as "foreign". The current focus in developing immune-based modalities is to potentiate an immune response against the existing, albeit weak, antigens expressed in the tumor. An alternative approach - the focus of this proposal - is to express new, and hence potent, antigens in tumor cells in situ. Two main challenges that have precluded the development of such strategies, how to express new antigens in the disseminated tumor lesions of the cancer patients and how to restrict expression of such antigens to the tumor, precluding their expression in normal tissue, are addressed by the approach described in this proposal. Expression of novel antigens in tumor cells will be achieved using siRNA technology to inhibit nonsense mediated mRNA decay (NMD), a surveillance mechanism which prevents the expression of mRNAs containing a premature termination codon. Targeting siRNA inhibition to tumor cells - an essential requisite because of the constitutive nature and physiological roles of the NMD process - will be achieved using a novel targeting technology comprised of oligonucleotide aptamer ligands. Aptamers or aptamer targeted siRNA conjugates, unlike antibodies, can be synthesized in a chemical process, providing a more straightforward and cost effective manufacturing and regulatory approval process to generate clinical grade reagents. The hypotheses tested in this proposal - supported by extensive preliminary studies - are: (I). NMD inhibition in tumor cells will result in the expression of novel products which will function as tumor rejection antigens eliciting an immune response that will negatively impact on tumor growth, and (II). Aptamer-targeted siRNA inhibition of NMD in tumor-bearing mice is sufficiently robust to inhibit tumor growth. The main objectives of the proposed studies-carried out in preclinical murine models - are to provide proof-of-concept that tumor targeted inhibition of NMD using aptamer-siRNA conjugates will elicit tumor immunity, and to determine how effective is the this novel approach, compared to best-in-class "conventional" tumor vaccination protocols in preventing and reversing tumor progression in mice. The specific aims of this proposal are: (1). To develop and characterize in vitro best-in-class PSMA aptamer targeted siRNAs corresponding to murine NMD-specific factors. (2). To evaluate the ability of PSMA aptamer-siRNA conjugates to engender antitumor immunity in tumor bearing mice. (3). To develop Her2 aptamer-siRNA conjugates and evaluate their ability to inhibit tumor growth in transplantable and spontaneous murine models for breast cancer. Successful completion of the studies proposed in this application will provide the rationale and guidelines for exploring aptamer targeted NMD inhibition to potentiate tumor immunogenicity in cancer patients.

描述（申请人提供）：肿瘤不受癌症患者免疫系统控制的主要原因是，与病原体不同，肿瘤不表达可被免疫系统识别为“外来”的有效肿瘤抗原。目前开发基于免疫的方法的重点是增强针对肿瘤中表达的现有抗原（尽管较弱）的免疫反应。另一种方法（该提案的重点）是在肿瘤细胞中原位表达新的、因此有效的抗原。该方法解决了阻碍此类策略发展的两个主要挑战，即如何在癌症患者的播散性肿瘤病变中表达新抗原以及如何限制此类抗原在肿瘤中的表达，从而阻止其在正常组织中的表达。本提案中描述。新抗原在肿瘤细胞中的表达将通过使用 siRNA 技术来抑制无义介导的 mRNA 衰减 (NMD) 来实现，NMD 是一种防止含有过早终止密码子的 mRNA 表达的监视机制。将 siRNA 靶向肿瘤细胞抑制——这是由于 NMD 过程的组成性质和生理作用所必需的——将使用由寡核苷酸适体配体组成的新型靶向技术来实现。与抗体不同，适体或适体靶向 siRNA 缀合物可以在化学过程中合成，从而提供更直接且更具成本效益的制造和监管审批流程来生成临床级试剂。本提案中测试的假设（得到广泛的初步研究的支持）是：（I）。肿瘤细胞中的 NMD 抑制将导致新产物的表达，这些新产物将充当肿瘤排斥抗原，引发免疫反应，从而对肿瘤生长产生负面影响，以及（II）。在荷瘤小鼠中，适体靶向 siRNA 对 NMD 的抑制作用足以抑制肿瘤生长。在临床前小鼠模型中进行的拟议研究的主要目标是提供概念证明，即使用适体-siRNA 缀合物对 NMD 进行肿瘤靶向抑制将引发肿瘤免疫，并确定这种新方法的有效性。与预防和逆转小鼠肿瘤进展的一流“传统”肿瘤疫苗接种方案相比。本提案的具体目标是： (1)．开发并表征体外一流的 PSMA 适体靶向 siRNA，该 siRNA 对应于小鼠 NMD 特异性因子。（2）。评估 PSMA 适体-siRNA 缀合物在荷瘤小鼠中产生抗肿瘤免疫的能力。（3）。开发 Her2 适体-siRNA 缀合物并评估其在可移植和自发性乳腺癌小鼠模型中抑制肿瘤生长的能力。本申请中提出的研究的成功完成将为探索适体靶向 NMD 抑制以增强癌症患者的肿瘤免疫原性提供原理和指南。