从质膜突起释放的大的非凋亡囊泡被归类为大 EV（LEV）。然而，LEV分泌的触发因素及其在肿瘤中的功能仍不清楚。通过癌细胞、腹膜间皮细胞(PMCs)和巨噬细胞(MΦs)的共培养系统来观察细胞-细胞接触介导的LEV分泌。使用 Wt1CreERT2-tdTnu 小鼠进行 PMC 谱系追踪，探讨 LEV 对 PMC 体内的影响，并通过 qRT-PCR 和流式细胞术评估淋巴管生成。在腹膜传播中，表达 Ephrin-B (EFNB) 的癌细胞分泌 LEV与表达肝配蛋白 B 型 (EphB) 受体的 PMC 接触后，该受体通过增强间皮-间质转化而降解间皮屏障。 LEV 被纳入胸膜下 MΦ，这些 MΦ 转分化为淋巴管内皮细胞 (LEC) 并整合到淋巴管中。 PMC 中的 LEC 分化也通过与 LEV 处理的 MΦ 相互作用而诱导，从而促进淋巴管生成。从机制上讲，通过 EFNB 反向信号激活 RhoA-ROCK 通路诱导 LEV 分泌。 LEVs 上的 EFNB 激活 PMC 和 MΦs 中的 EphB 前向信号传导，激活 Akt、ERK 和 TGF-β1 通路，这对于引起 MMT 和 LEC 分化是必不可少的。 LEV 加速了癌细胞的腹膜传播和淋巴侵袭。使用 EphB-Fc 融合蛋白阻断 LEV 上的 EFNB 可减弱这些事件。EFNB 高癌细胞在附着到 PMC 时分散 LEV，从而增强了 PMC 和 MΦ（MMT 和淋巴管生成）的局部反应并夸大了腹膜播散。© 2024。作者获得施普林格自然有限公司的独家许可。

Large non-apoptotic vesicles released from the plasma membrane protrusions are classified as large-EVs (LEVs). However, the triggers of LEV secretion and their functions in tumors remain unknown.Coculture system of cancer cells, peritoneal mesothelial cells (PMCs), and macrophages (MΦs) was conducted to observe cell-cell contact-mediated LEV secretion. Lineage tracing of PMCs was performed using Wt1CreERT2-tdTnu mice to explore the effects of LEVs on PMCs in vivo, and lymphangiogenesis was assessed by qRT-PCR and flow-cytometry.In peritoneal dissemination, cancer cells expressing Ephrin-B (EFNB) secreted LEVs upon the contact with PMCs expressing ephrin type-B (EphB) receptors, which degraded mesothelial barrier by augmenting mesothelial-mesenchymal transition. LEVs were incorporated in subpleural MΦs, and these MΦs transdifferentiated into lymphatic endothelial cells (LEC) and integrated into the lymphatic vessels. LEC differentiation was also induced in PMCs by interacting with LEV-treated MΦs, which promoted lymphangiogenesis. Mechanistically, activation of RhoA-ROCK pathway through EFNB reverse signaling induced LEV secretion. EFNBs on LEVs activated EphB forward signaling in PMC and MΦs, activating Akt, ERK and TGF-β1 pathway, which were indispensable for causing MMT and LEC differentiation. LEVs accelerated peritoneal dissemination and lymphatic invasions by cancer cells. Blocking of EFNBs on LEVs using EphB-Fc-fusion protein attenuated these events.EFNBhigh cancer cells scattered LEVs when they attached to PMCs, which augmented the local reactions of PMC and MΦ (MMT and lymphangiogenesis) and exaggerated peritoneal dissemination.© 2024. The Author(s), under exclusive licence to Springer Nature Limited.