基于Ca2+-calcineurin-NFAT2和 IDO1-Kyn-AhR双重信号抑制的小分子组合药物抗肿瘤疗效及肿瘤免疫机制研究

Cancer immunotherapy is called "the third revolution" of cancer treatment, which has shown striking clinical results in the treatment of various malignant tumors by activating the immune system and triggering cytotoxic functions of immune cells in tumor microenvironment for killing tumor cells. The roles of small-molecule compounds have not, however, been fully realized in this area. Carboxyamidotriazole (CAI) is a kind of non-cytotoxic small-molecule drug, which has both anti-inflammatory and anti-tumor activities. Our previous study found that CAI not only inhibits the proliferation of tumor cells, but also inhibits the nuclear translocation of NF-κB as well as that of NFAT in T cells, and further modulates the function of T cells. However, CAI increases the expression of IDO1 enzyme and facilitates the production of KYN in tumor microenvironment, leading to tumor immune escape. The project intends to systematically evaluate the regulating effects of CAI on Ca2+-calcineurin-NFAT2 and IDO1-Kyn-AhR pathways using a number of biological and immunological techniques to explore the role of CAI in T cells. Meanwhile, certain IDO1-Kyn-AhR signaling pathway inhibitors will be severally used in combination with CAI to abolish its potential negative effect on T cells. With dual-blockade of Ca2+-calcineurin-NFAT2 and IDO1-Kyn-AhR pathways, T cells activation might be synergistically enhanced and immune surveillance will restore. Based on complementary modulation mode of small-molecule compounds, the project will establish a new, multi-target cancer immunotherapy strategy, push ahead basic research around the function of T cells in tumor microenvironment as well as innovative small-molecule drug research in area of cancer immunotherapy.

肿瘤免疫治疗被称为抗癌治疗的“第三次革命”，而在这一领域，小分子化合物的作用尚未得到充分的认识。羧胺三唑能够调控肿瘤微环境，并通过抑制钙内流阻断活化的T细胞核因子（NFAT）入核，调节T细胞功能。但该药物上调肿瘤IDO1酶表达，增加肿瘤微环境中犬尿氨酸的水平，可能导致肿瘤细胞的免疫逃逸。本项目拟综合应用多项生物学和免疫学技术，系统评价羧胺三唑对Ca2+-钙调磷酸酶-NFAT2和IDO1-犬尿氨酸-AhR信号的调节，探索药物对T细胞的作用。同时采用IDO1-犬尿氨酸-AhR信号通路抑制剂，消除羧胺三唑对T细胞的不利影响，实现Ca2+-钙调磷酸酶-NFAT2 和IDO1-犬尿氨酸-AhR双通路抑制，协同加强T细胞的活化，恢复免疫监察。基于小分子化合物的互补调控模式，本项目将建立全新的多靶点肿瘤免疫治疗策略，推动肿瘤微环境中T细胞功能调节的基础研究和肿瘤免疫治疗领域的小分子创新药物研究。

项目背景：.肿瘤免疫治疗被称为抗癌治疗的“第三次革命”，它通过激活免疫系统，启动肿瘤微环境中免疫细胞的杀伤功能消灭肿瘤细胞，在多种恶性肿瘤的治疗中取得令人振奋的结果。而在这一领域，小分子化合物的作用尚未得到充分的阐述。羧胺三唑是一种非细胞毒类小分子药物，兼具抗炎、抗肿瘤活性。前期工作发现该药物不仅抑制肿瘤细胞增殖，还可活化T细胞核因子入核，调节T细胞功能。然而羧胺三唑上调肿瘤IDO1酶表达，增加微环境中犬尿氨酸的水平，可能导致肿瘤细胞的免疫逃逸。.主要研究内容：.本项目综合应用多项分子生物学、免疫学、药理学实验方法，系统评价了羧胺三唑对钙离子-钙调磷酸酶-活化T细胞核因子和IDO1-犬尿氨酸-芳烃受体信号的调节，探索药物对T细胞的作用。.具体研究内容包括：1）CAI联合IDO1- Kyn-AhR通路抑制剂增强肿瘤免疫治疗的研究；2）CAI对细胞休眠-凋亡振荡状态的调节；3）联合用药产生的协同抗肿瘤作用研究。.重要结果和关键数据：.1) CAI通过增加IFN-γ水平加强CD8+ T细胞杀伤能力;.2) CAI激活IDO1-Kyn代谢回路，进一步激活Kyn-AhR通路来掩盖T细胞的潜在缺陷;.3) CAI与1-MT或DMF协同抑制CD8+ T细胞PD-1表达并促进IFN-γ产生;.4) CAI联合DMF或1-MT可增加肿瘤浸润细胞毒性CD8+ T细胞数量，降低PD-1表达;.5) CAI联合IDO1/AhR抑制剂影响B16-OVA荷瘤小鼠过继T细胞的表型和功能，显示出有益的抗癌作用.6) IDO1或AhR抑制剂增强了CAI对异种移植瘤的治疗作用.7) CAI在体外、体内诱导结直肠癌细胞进入休眠状态，其机制可能与IDO-Kyn-AhR-p21通路激活有关.8）CAI联合1-MT或DMF可促进磷酸化STAT1的核转位，协同诱导结直肠癌细胞凋亡.9）CAI联合1-MT或DMF协同抑制结直肠癌细胞的肿瘤生长，提高荷瘤小鼠的存活率.科学意义：本项目基于小分子化合物的互补调控模式，提出了全新的多靶点肿瘤免疫治疗策略，推动了肿瘤微环境中T细胞功能调节的基础研究和肿瘤免疫治疗领域的小分子创新药物研究。