School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
Department of General Surgery, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai, 200092, China.
J Ethnopharmacol. 2023 Sep 15;313:116491. doi: 10.1016/j.jep.2023.116491. Epub 2023 Apr 16.
The traditional Chinese medicine (TCM) Tian-Men-Dong decoction (TD) has been able to effectively treat lung cancer in China for thousands of years. TD improves the quality of life in lung cancer patients by promoting nourishment of yin and reducing dryness, clearing the lung and removing toxins. Pharmacological studies show that TD contains active antitumour ingredients, but its underlying mechanism remains unknown.
This study aims at exploring potential mechanisms of TD in the treatment of lung cancer by regulating granulocytic-myeloid-derived suppressor cells (G-MDSCs).
An orthotopic lung cancer mouse model was generated by intrapulmonary injection with LLC-luciferase cells in immunocompetent C57BL/6 mice or immunodeficient nude mice. TD/saline was orally administered once to the model mice daily for 4 weeks. Live imaging was conducted to monitor tumour growth. Immune profiles were detected by flow cytometry. H&E and ELISA were applied to test the cytotoxicity of the TD treatment. RT-qPCR and western blotting were performed to detect apoptosis-related proteins in G-MDSCs. A neutralizing antibody (anti-Ly6G) was utilized to exhaust the G-MDSCs via intraperitoneal injection. G-MDSCs were adoptively transferred from wild-type tumour-bearing mice. Immunofluorescence, TUNEL and Annexin V/PI staining were conducted to analyse apoptosis-related markers. A coculture assay of purified MDSCs and T cells labelled with CFSE was performed to test the immunosuppressive activity of MDSCs. The presence of TD/IL-1β/TD + IL-1β in purified G-MDSCs cocultured with the LLC system was used for ex vivo experiments to detect IL-1β-mediated apoptosis of G-MDSCs.
TD prolonged the survival of immune competent C57BL/6 mice in an orthotopic lung cancer model, but did not have the same effect in immunodeficient nude mice, indicating that its antitumour properties of TD are exerted by regulating immunity. TD induced G-MDSC apoptosis via the IL-1β-mediated NF-κB signalling cascade leading to effectively weaken the immunosuppressive activity of G-MDSCs and promote CD8 T-cell infiltration, which was supported by both the depletion and adoptive transfer of G-MDSCs assays. In addition, TD also showed minimal cytotoxicity both in vivo and in vitro.
This study reveals for the first time that TD, a classic TCM prescription, is able to regulate G-MDSC activity and trigger its apoptosis via the IL-1β-mediated NF-κB signalling pathway, reshaping the tumour microenvironment and demonstrating antitumour effects. These findings provide a scientific foundation the clinical treatment of lung cancer with TD.
ETHNOPHARMACOLOGICAL 相关性：传统中药（TCM）天门冬汤（TD）在中国已经能够有效地治疗肺癌数千年。TD 通过促进滋阴和减少干燥、清肺解毒来提高肺癌患者的生活质量。药理研究表明，TD 含有活性抗肿瘤成分，但其潜在机制尚不清楚。
本研究旨在通过调节粒细胞-髓样来源的抑制细胞（G-MDSCs）来探索 TD 治疗肺癌的潜在机制。
通过向免疫功能正常的 C57BL/6 小鼠或免疫缺陷的裸鼠肺内注射 LLC-荧光素酶细胞，生成原位肺癌小鼠模型。将 TD/生理盐水每日口服一次给予模型小鼠，连续 4 周。通过活体成像监测肿瘤生长。流式细胞术检测免疫谱。H&E 和 ELISA 用于检测 TD 治疗的细胞毒性。RT-qPCR 和 Western blot 用于检测 G-MDSC 中与凋亡相关的蛋白。通过腹腔内注射中和抗体（抗 Ly6G）耗尽 G-MDSC。从野生型荷瘤小鼠中过继转移 G-MDSC。免疫荧光、TUNEL 和 Annexin V/PI 染色用于分析凋亡相关标志物。用 CFSE 标记纯化的 MDSC 和 T 细胞进行共培养实验，以检测 MDSC 的免疫抑制活性。将 TD/IL-1β/TD+IL-1β 加入与 LLC 系统共培养的纯化 G-MDSC 中进行离体实验，以检测 G-MDSC 中 IL-1β 介导的凋亡。
TD 延长了免疫功能正常的 C57BL/6 小鼠在原位肺癌模型中的存活期，但在免疫缺陷的裸鼠中没有相同的效果，这表明 TD 的抗肿瘤特性是通过调节免疫发挥作用的。TD 通过 IL-1β 介导的 NF-κB 信号级联诱导 G-MDSC 凋亡，从而有效削弱 G-MDSC 的免疫抑制活性，并促进 CD8 T 细胞浸润，这一点通过 G-MDSC 的耗竭和过继转移实验得到了支持。此外，TD 在体内和体外均显示出最小的细胞毒性。
本研究首次揭示，经典中药方剂 TD 能够通过 IL-1β 介导的 NF-κB 信号通路调节 G-MDSC 活性并触发其凋亡，重塑肿瘤微环境并表现出抗肿瘤作用。这些发现为 TD 治疗肺癌的临床治疗提供了科学依据。
