siRNA-based Gold Nanoparticles as a Therapeutic Enhancer for Triple Negative Breast Cancer (TNBC) Radiotherapy

摘要 放射治疗（RT）调节肿瘤微环境（TME）的免疫学特性，以刺激肿瘤微环境（TME）。 抗肿瘤免疫反应然而，RT也启动免疫抑制机制，因此 减少RT免疫刺激的作用。主要的RT免疫抑制模式之一是通过以下方式发挥作用： 乳腺癌（BC）中TGF β 1产生的增加对已经很高的TGF β 1水平具有累加效应 由癌细胞自身产生。特别是三阴性乳腺癌（TNBC），被证明是 与其他BCs相比，TGF β 1水平更高，这一发现与肿瘤分级增加相关， 侵袭性和患者存活率降低。因此，RT诱导TME内TGF β 1的增加， 可能进一步增强TNBC的侵袭性和转移潜力。由于RT的刺激性方面 免疫调节，RT作为癌症免疫治疗中的一种有前景的治疗增强剂而引起了人们的兴趣， 例如免疫检查点阻断剂，在改善局部控制和总体 在特定癌症中的存活率。不幸的是，在大多数形式的BC中，包括TNBC， 保持谦虚。我们的长期目标是使用RT来增强TNBC对免疫疗法的反应， RT免疫调节潜力的优势。抗肿瘤RT效应，包括TME免疫调节，可 通过使用放射增敏剂如金纳米颗粒（AuNP）来改善。此外，AuNP还可以用作 通过小干扰RNA（siRNA）缀合的药物递送系统。在这个项目中，我们建议使用 通过TGF β siRNA功能性修饰的AuNPs，以同时增强RT免疫调节和抵消 免疫抑制作用与TGF β 1产生增加有关。这种方法将增强RT 这有助于提高抗肿瘤作用，并为未来的免疫治疗创造有利的TME环境。这 将通过以下具体目的进行测试：目的1：合成和表征AuNP-siRNATGF β 1;目的 2：研究RT与AuNP-siRNATGFβ1联合应用的体内外疗效 小鼠TNBC模型。所提出的确定AuNPs同时靶向 抗肿瘤和免疫调节RT效应将为改善TNBC对 免疫检查点阻断剂和用于设计未来的RT/免疫检查点阻断剂的多模式TNBC 治疗

ABSTRACT Radiation therapy (RT) modulates immunological properties of tumor microenvironment (TME) to stimulate antitumor immune response. However, RT initiates immunosuppressive mechanisms as well and therefore diminishing the effects of RT immuno-stimulation. One of the main RT immunosuppressive modes is exerted by an increase in TGF production that in breast cancers (BC) has an additive effect on already high TGF levels produced by cancer cells themselves. Triple negative breast cancer (TNBC) in particular, was demonstrated to have higher TGF levels compared to other BCs, and this finding correlated with increased tumor grade and invasiveness, and a diminished patient survival. Consequently, RT induced increase in TGF within the TME may further potentiate invasiveness and metastatic potential of TNBC. Due to stimulatory aspects of RT immunomodulation, RT has gained interest as a prospective therapeutic enhancer in cancer immunotherapy, such as immune checkpoint blockers, that has shown great potential in improving local control and overall survival in select cancers. Unfortunately, in most forms of BC, including TNBC, response to immunotherapy remains modest. Our long-term goal is to use RT to enhance TNBC response to immunotherapy by taking advantage of RT immunomodulatory potential. Antitumor RT effects, including TME immunomodulation can be improved by using radiosensitizers, such as gold nanoparticles (AuNP). Furthermore, AuNPs can also serve as a drug delivery system by conjugation of small interfering RNAs (siRNAs). In this project we propose to use AuNPs functionally modified by TGF siRNA to simultaneously enhance RT immunomodulation and counteract the immunosuppressive effects related to the increased TGF production. This approach will enhance RT antitumor effects and create a favorable TME environment for better response to future immunotherapies. This will be tested by the following specific aims: Aim 1: To synthesize and characterize AuNP-siRNATGF1; Aim 2: To investigate the therapeutic effect of combination of RT and AuNP-siRNATGFβ1 in in vitro and in vivo mouse TNBC model. The proposed studies in determining the potential of AuNPs simultaneously target antitumor and immunomodulatory RT effects will provide critical information for improving TNBC response to immune checkpoint blockers and for designing future RT/ immune checkpoint blockers multimodal TNBC therapies.