[摘 要] 树突状细胞（DC）作为抗肿瘤免疫应答的核心启动者与调控者，已成为肿瘤免疫治疗的重要靶点。DC疫苗等靶向DC的免疫治疗策略在抗肿瘤治疗中展现出独特优势，但仍存在抗原提呈效率不足、免疫抑制微环境抵抗、功能特异性调控困难等瓶颈问题。肿瘤微环境（TME）中的DC存在高度异质性，不同DC亚群在分化发育、免疫调控及效应转归方面呈现复杂的多样性。解析DC亚群的精确表型与功能机制对于开发新型DC靶向性免疫治疗策略具有重要意义。TME中募集的经典DC、浆细胞样DC、单核细胞来源DC能与肿瘤浸润免疫细胞和微环境中的非免疫细胞（包括肿瘤细胞、成纤维细胞、内皮细胞等）相互作用激活抗肿瘤免疫应答，而TME还会通过转录调控、表观遗传调控、代谢重塑等多种方式抑制DC招募和抗原提呈能力，甚至诱导其向耐受性DC转化。值得注意的是，新近发现的富含免疫调节分子的成熟DC具有双向免疫调控作用，其起源路径和免疫调控网络仍有待深入研究。随着单细胞分析与空间组学分析等技术的发展，有望在单细胞分辨率下系统解析DC亚群的功能多样性及其与TME的时空相互作用网络，为开发下一代精准免疫治疗策略提供新靶点和新思路。

Pristimerin, which is one of the compounds present in Celastraceae and Hippocrateaceae, has antitumor effects. However, its mechanism of action in esophageal squamous cell carcinoma (ESCC) remains unclear. This study aims to investigate the efficacy and mechanism of pristimerin on ESCC in vitro and in vivo. The inhibitory effect of pristimerin on cell growth was assessed using trypan blue exclusion and colony formation assays. Cell apoptosis was evaluated by flow cytometry. Gene and protein expressions were analyzed through quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry. RNA sequencing (RNA-Seq) was employed to identify significantly differentially expressed genes (DEGs). Cell transfection and RNA interference assays were utilized to examine the role of key proteins in pristimerin?s effect. Xenograft models were established to evaluate the antitumor efficiency of pristimerin in vivo. Pristimerin inhibited cell growth and induced apoptosis in ESCC cells. Upregulation of Noxa was crucial for pristimerin-induced apoptosis. Pristimerin activated the Forkhead box O3a (FoxO3a) signaling pathway and triggered FoxO3a recruitment to the Noxa promoter, leading to Noxa transcription. Blocking FoxO3a reversed pristimerin-induced Noxa upregulation and cell apoptosis. Pristimerin treatment suppressed xenograft tumors in nude mice, but these effects were largely negated in Noxa-KO tumors. Furthermore, the chemosensitization effects of pristimerin in vitro and in vivo were mediated by Noxa. This study demonstrates that pristimerin exerts an antitumor effect on ESCC by inducing AKT/FoxO3a-mediated Noxa upregulation. These findings suggest that pristimerin may serve as a potent anticancer agent for ESCC treatment.
Forkhead Box Protein O3/genetics* ; Humans ; Apoptosis/drug effects* ; Esophageal Squamous Cell Carcinoma/physiopathology* ; Esophageal Neoplasms/physiopathology* ; Pentacyclic Triterpenes ; Animals ; Cell Line, Tumor ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Mice ; Signal Transduction/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Triterpenes/pharmacology* ; Xenograft Model Antitumor Assays ; Mice, Inbred BALB C ; Male ; Gene Expression Regulation, Neoplastic/drug effects*