Wang Han, Huang Renhong, Luo Lei, Wang Ruo, Zhou Ziling, Hong Jin, Wu Jiayi, Huang Ou, He Jianrong, Chen Weiguo, Li Yafen, Chen Xiaosong, Wang Yang, Wang Zheng, Shen Kunwei
Department of General Surgery, Comprehensive Breast Health Center, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Institute of Microsurgery on Extremities, Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
J Extracell Vesicles. 2025 Aug;14(8):e70154. doi: 10.1002/jev2.70154.
Small extracellular vesicles (sEV) are a class of natural vesicles rich in heterogeneous cargos with the great advantage of non-invasive detection; these vesicles exhibit complex intercellular crosstalk and mediate important biological functions. However, the potential value of plasma sEV in clinical prognosis prediction of triple-negative breast cancer (TNBC) and their biological functions have not been well elucidated. In this study, we isolated sEV from non-metastatic and metastatic TNBC plasma samples. We found that the expression of reticulin 4 (RTN4) in metastatic patients was significantly higher than that in non-metastatic patients. At the same time, clinical data showed that RTN4 was associated with poor prognosis and advanced-stage TNBC patients. Subsequently, in vivo and in vitro assays showed that compared to RTN4 sEV, RTN4 sEV significantly promoted tumour cell migration, invasion, epithelial-mesenchymal transition (EMT) and lung metastasis, and upregulated the expression of PD-L1 in tumour tissues and inhibited CD8T cell infiltration. Regarding mechanism research, we found that RTN4 within sEV drives tumour EMT and PD-L1 expression by activating the NF-κB signalling pathway. Further, through the combined treatment experiment of anti-PD-1 and anti-RTN4, it was found that the combination of the two drugs was significantly superior to monotherapy in inhibiting tumour metastasis, EMT, and promoting CD8T cell infiltration. Our results highlight the molecular mechanism of sEV protein RTN4 in tumour progression and immune system regulation, indicating that RTN4 targeting and anti-PD-1 combined therapy have clinical potential. sEV protein RTN4 is a potential new prognostic marker for non-invasive detection of TNBC and a new target for TNBC treatment.
小细胞外囊泡（sEV）是一类富含异质性 cargo 的天然囊泡，具有非侵入性检测的巨大优势；这些囊泡表现出复杂的细胞间串扰并介导重要的生物学功能。然而，血浆 sEV 在三阴性乳腺癌（TNBC）临床预后预测中的潜在价值及其生物学功能尚未得到充分阐明。在本研究中，我们从非转移性和转移性 TNBC 血浆样本中分离出 sEV。我们发现，转移性患者中网蛋白 4（RTN4）的表达明显高于非转移性患者。同时，临床数据显示 RTN4 与预后不良及晚期 TNBC 患者相关。随后，体内和体外试验表明，与 RTN4 阴性的 sEV 相比，RTN4 阳性的 sEV 显著促进肿瘤细胞迁移、侵袭、上皮-间质转化（EMT）和肺转移，并上调肿瘤组织中 PD-L1 的表达，抑制 CD8T 细胞浸润。关于机制研究，我们发现 sEV 中的 RTN4 通过激活 NF-κB 信号通路驱动肿瘤 EMT 和 PD-L1 表达。此外，通过抗 PD-1 和抗 RTN4 的联合治疗实验，发现两种药物联合在抑制肿瘤转移、EMT 和促进 CD8T 细胞浸润方面明显优于单一疗法。我们的结果突出了 sEV 蛋白 RTN4 在肿瘤进展和免疫系统调节中的分子机制，表明靶向 RTN4 和抗 PD-1 联合治疗具有临床潜力。sEV 蛋白 RTN4 是 TNBC 非侵入性检测潜在的新预后标志物和 TNBC 治疗的新靶点。
