Ren Jiaojiao, Ying Jun, Liu Haijian, Hu Shanshan, Li Jiangdong, Zhou Danfei
Department of Respiratory and Critical Care Medicine, Ningbo No. 2 Hospital, Ningbo, China.
J Interferon Cytokine Res. 2025 Jan;45(1):29-37. doi: 10.1089/jir.2024.0150. Epub 2025 Jan 8.
This study was designed to explore the action mechanism of stimulator of interferon genes (STING) on the differentiation of myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment of lung cancer. Bioinformatics analysis yielded a potential pathway for STING to regulate MDSC differentiation, the interferon regulatory factor 3 (IRF3)/NF-κB axis. The transfection efficiency of STING overexpression plasmid and small interfering RNA against IRF3 (siIRF3) was examined by quantitative real-time polymerase chain reaction (qRT-PCR). After transfection, A9 cells were co-cultured with extracted bone marrow cells (BMCs). MDSC differentiation, protein expression of the IRF3/NF-κB pathway, and changes in nuclear translocation of NF-κB were analyzed by flow cytometry, Western blot, and immunofluorescence staining experiments. A transplanted tumor mouse model was used for experiments. After cyclic diadenyl monophosphate (CDA; STING agonist) treatment, changes in MDSC differentiation and protein expression of the IRF3/NF-κB axis in transplanted tumors were verified by immunohistochemical staining, qRT-PCR, and Western blot. Coculture of A9 cells and BMCs promoted MDSC differentiation, inhibited activation of IRF3/NF-κB signal in A9 cells, and boosted nuclear translocation of NF-κB. However, after the upregulation of STING, IRF3/NF-κB signal was activated, while MDSC differentiation and nuclear translocation of NF-κB were inhibited. SiIRF3 reversed the effects of STING overexpression. , CDA dampened MDSC differentiation and promoted protein expression of the IRF3/NF-κB axis. STING signal in lung cancer cells inhibits MDSC differentiation through activation of the IRF3/NF-κB pathway.
本研究旨在探讨干扰素基因刺激因子（STING）在肺癌肿瘤微环境中对髓源性抑制细胞（MDSCs）分化的作用机制。生物信息学分析得出STING调节MDSC分化的潜在途径，即干扰素调节因子3（IRF3）/核因子κB（NF-κB）轴。通过定量实时聚合酶链反应（qRT-PCR）检测STING过表达质粒和针对IRF3的小干扰RNA（siIRF3）的转染效率。转染后，将A9细胞与提取的骨髓细胞（BMCs）共培养。通过流式细胞术、蛋白质免疫印迹法和免疫荧光染色实验分析MDSC分化、IRF3/NF-κB途径的蛋白质表达以及NF-κB核转位的变化。使用移植瘤小鼠模型进行实验。经环二磷酸腺苷（CDA；STING激动剂）处理后，通过免疫组织化学染色、qRT-PCR和蛋白质免疫印迹法验证移植瘤中MDSC分化和IRF3/NF-κB轴的蛋白质表达变化。A9细胞与BMCs共培养促进了MDSC分化，抑制了A9细胞中IRF3/NF-κB信号的激活，并增强了NF-κB的核转位。然而，STING上调后，IRF3/NF-κB信号被激活，而MDSC分化和NF-κB核转位受到抑制。SiIRF3逆转了STING过表达的作用。此外，CDA抑制了MDSC分化并促进了IRF3/NF-κB轴的蛋白质表达。肺癌细胞中的STING信号通过激活IRF3/NF-κB途径抑制MDSC分化。
