Project 1: Inhibition of Complement C5aR1 Radioprotects Normal Tissue and Radiosensitizes Tumors

项目 1：抑制补体 C5aR1 辐射保护正常组织并使肿瘤辐射增敏

• 批准号: 10707880
• 负责人: Amato J. Giaccia
• 金额: $ 22.78万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-21 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10707880
• 关键词: Animal Model; Apoptosis; Attenuated; Cancer Model; Cell Culture Techniques; Cell Survival; Cells; Clinic; Collaborations; Colorectal Cancer; Colorectal Neoplasms; Complement; Complement Receptor; Data; Dependence; Disease; Ensure; Epithelium; Exhibits; Gastrointestinal tract structure; Genetic; Histologic; Immune; Immunity; In Vitro; Interleukin-10; Intestines; Lung; Macrophage; Malignant Neoplasms; Mediating; Methods; Modeling; Molecular; Mus; Natural Immunity; Normal tissue morphology; Pathway interactions; Phosphorylation; Population; Process; Proto-Oncogene Proteins c-akt; Radiation; Radiation Protection; Radiation induced damage; Radiation therapy; Radiation-Sensitizing Agents; Radiosensitization; Role; Salivary Glands; Schedule; Signal Transduction; Site; Small Intestines; Stress; TP53 gene; Therapeutic; Therapeutic Index; Tissues; Toxic effect; Tumor Promotion; Tumor Tissue; angiogenesis; antagonist; cell killing; clinical effect; colon cancer cell line; complement pathway; complement system; crypt cell; data sharing; dosimetry; effectiveness evaluation; gastrointestinal; gastrointestinal epithelium; gastrointestinal system; improved; in vivo; inhibitor; intestinal injury; irradiation; molecular targeted therapies; neoplastic cell; pharmacologic; radiation response; radioprotected; recruit; response; targeted treatment; tumor; tumor progression

Abstract (Project 1 - Oxford) Increasing the therapeutic window of radiotherapy may be achieved by using targeted therapies against cancer- associated pathways. The complement system is an innate immunity pathway, with emerging roles in cancer progression. No study has evaluated the effect of complement inhibition on both tumor and normal tissue radiation response. Here we show that targeting complement receptor C5aR1 improves radiation response in colorectal cancer models while reducing radiation-induced toxicity. Targeting C5aR1 increases IL-10 secretion, which attenuates NF-κB signaling and enhances apoptosis in tumor cells. IL-10-dependent apoptosis is observed both in vivo and in vitro suggesting a non-canonical stress-specific and likely immune-independent role for C5aR1 in regulating apoptosis. Importantly, we find that C5aR1 depletion results in decreased small intestinal histologic damage, crypt cell apoptosis and increased survival of mice following irradiation. In the small intestine, C5aR1 depletion results in increased IL-10 expression in both non-immune and immune cell populations. IL-10 signaling in CX3CR1+ macrophages is important for intestinal injury defense and C5aR1-/- mice have significantly higher levels of CX3CR1+ macrophages than WT mice. In response to irradiation, C5aR1 depletion does not attenuate NF-κB signaling but instead increases AKT activation correlating with decreased apoptosis occurring in an IL-10-depedent manner. Our data, therefore, indicate that genetically or pharmacologically targeting C5aR1 can improve radiation response in colorectal tumor models while reducing radiation-induced small bowel toxicity. Together, these findings suggest that inhibiting complement could be a promising approach to increasing the therapeutic window of radiotherapy. In this Project, we propose four specific aims to better understand the role of C5aR1 in radioprotection and radiosensitization. Aim 1 will determine the broad versus specific protection of normal epithelium (intestines, salivary glands, and lung epithelium) by C5aR1-/- mice in response fractionated and hypofractionated radiotherapy, in collaboration with Projects 2, 3, 4 and Core B. In Aim 2, we will investigate the mechanistic basis of radioprotection when C5aR1 is inhibited. Our preliminary data indicates that this is an IL-10 dependent mechanism and involves recruitment of CX3CR1+ macrophages that promote survival and angiogenesis. Aim 3 will determine how C5aR1 promotes tumor cell killing in combination with radiotherapy. The hypothesis based on our preliminary data is that C5aR1 inhibition increases IL-10 secretion, which attenuates NF-κB signaling, resulting in IL-10 dependent tumor cell killing both in cell culture and in animal models. Aim 4 will determine the effect of clinical grade C5aR1 inhibitors on radioprotecting intestine, salivary glands and lungs, and sensitizing colorectal tumors to radiotherapy. I intend to return to Stanford on a monthly or bimonthly schedule and will share this data with my colleagues at Stanford. At Oxford, we perform our own dosimetry and will cooperate with Core B at Stanford to ensure comparability of methods.

摘要（项目 1 - 牛津） 通过使用针对癌症的靶向疗法可以增加放射治疗的治疗窗。 相关途径。补体系统是一种先天免疫途径，在癌症中发挥着新的作用 进展。尚无研究评估补体抑制对肿瘤和正常组织的影响 辐射反应。在这里，我们表明靶向补体受体 C5aR1 可以改善放射反应 结直肠癌模型，同时减少辐射引起的毒性。靶向 C5aR1 增加 IL-10 分泌， 它减弱 NF-κB 信号传导并增强肿瘤细胞的凋亡。 IL-10依赖性细胞凋亡是 在体内和体外观察到的结果表明其具有非典型的应激特异性且可能与免疫无关的作用 C5aR1 调节细胞凋亡。重要的是，我们发现 C5aR1 耗竭导致小肠减少 组织学损伤、隐窝细胞凋亡和辐射后小鼠存活率增加。在小肠中， C5aR1 耗竭导致非免疫细胞和免疫细胞群中 IL-10 表达增加。白细胞介素10 CX3CR1+巨噬细胞中的信号传导对于肠道损伤防御很重要，并且 C5aR1-/- 小鼠具有显着的 CX3CR1+巨噬细胞水平高于WT小鼠。响应辐射，C5aR1 耗竭不会 减弱 NF-κB 信号转导，但反而增加 AKT 激活，与细胞凋亡减少相关 以 IL-10 依赖性方式。因此，我们的数据表明，通过基因或药理学靶向 C5aR1 可以改善结直肠肿瘤模型的放射反应，同时减少放射引起的小肠毒性。 总之，这些发现表明，抑制补体可能是增加补体的一种有前途的方法。 放射治疗的治疗窗。在这个项目中，我们提出了四个具体目标，以更好地理解这一角色 C5aR1 在放射防护和放射增敏中的作用。目标 1 将确定广泛与具体的保护 C5aR1-/- 小鼠响应分级的正常上皮（肠、唾液腺和肺上皮） 和大分割放射治疗，与项目 2、3、4 和核心 B 合作。在目标 2 中，我们将调查 C5aR1 被抑制时辐射防护的机制基础。我们的初步数据表明，这是一个 IL-10 依赖性机制，涉及招募 CX3CR1+ 巨噬细胞，促进生存和 血管生成。目标 3 将确定 C5aR1 如何与放疗结合促进肿瘤细胞杀伤。 基于我们初步数据的假设是，C5aR1 抑制会增加 IL-10 的分泌，这 减弱 NF-κB 信号传导，导致细胞培养物和动物体内的 IL-10 依赖性肿瘤细胞杀伤 模型。目标 4 将确定临床级 C5aR1 抑制剂对肠道、唾液的辐射防护作用 腺体和肺部，并使结直肠肿瘤对放射治疗敏感。我打算每月返回斯坦福一次 或每两个月一次的计划，并将与我在斯坦福大学的同事分享这些数据。在牛津，我们执行自己的 剂量测定并将与斯坦福大学的 Core B 合作，以确保方法的可比性。