Peanut agglutinin (PNA) is a carbohydrate-binding protein in peanuts that accounts for ~0.15% peanut weight. PNA is highly resistant to cooking and digestion and is rapidly detectable in the blood after peanut consumption. Our previous studies have shown that circulating PNA mimics the actions of endogenous galactoside-binding protein galectin-3 by interaction with tumour cell-associated MUC1 and promotes circulating tumour cell metastatic spreading. The present study shows that circulating PNA interacts with micro- as well as macro-vascular endothelial cells and induces endothelial secretion of cytokines MCP-1 (CCL2) and IL-6 in vitro and in vivo. The increased secretion of these cytokines autocrinely/paracrinely enhances the expression of endothelial cell surface adhesion molecules including integrins, VCAM and selectin, leading to increased tumour cell-endothelial adhesion and endothelial tubule formation. Binding of PNA to endothelial surface MCAM (CD146), via N-linked glycans, and subsequent activation of PI3K-AKT-PREAS40 signalling is here shown responsible for PNA-induced secretion of MCP-1 and IL-6 by vascular endothelium. Thus, in addition to its influence on promoting tumour cell spreading by interaction with tumour cell-associated MUC1, circulating PNA might also influence metastasis by enhancing the secretion of metastasis-promoting MCP-1 and IL-6 from the vascular endothelium.

中文翻译：

---

花生摄入后血液循环中花生凝集素的出现促进了促转移细胞因子的内皮分泌。

花生凝集素 (PNA) 是花生中的一种碳水化合物结合蛋白，约占花生重量的 0.15%。PNA 对烹饪和消化具有很强的抵抗力，并且在食用花生后可在血液中迅速检测到。我们之前的研究表明，循环 PNA 通过与肿瘤细胞相关 MUC1 相互作用模拟内源性半乳糖苷结合蛋白 galectin-3 的作用，并促进循环肿瘤细胞转移扩散。本研究表明，循环 PNA 与微血管和大血管内皮细胞相互作用，并在体外和体内诱导细胞因子 MCP-1 (CCL2) 和 IL-6 的内皮分泌。这些细胞因子自分泌/旁分泌增加的分泌增强了内皮细胞表面粘附分子的表达，包括整合素、VCAM 和选择素，导致肿瘤细胞-内皮粘附增加和内皮小管形成。PNA 与内皮表面 MCAM (CD146) 的结合，通过 N 连接聚糖，以及随后 PI3K-AKT-PREAS40 信号的激活，在此处显示负责 PNA 诱导的血管内皮分泌 MCP-1 和 IL-6。因此，除了通过与肿瘤细胞相关的 MUC1 相互作用对促进肿瘤细胞扩散的影响外，循环 PNA 还可能通过增强血管内皮中促进转移的 MCP-1 和 IL-6 的分泌来影响转移。此处显示 PI3K-AKT-PREAS40 信号的随后激活负责 PNA 诱导的血管内皮分泌 MCP-1 和 IL-6。因此，除了通过与肿瘤细胞相关的 MUC1 相互作用对促进肿瘤细胞扩散的影响外，循环 PNA 还可能通过增强血管内皮中促进转移的 MCP-1 和 IL-6 的分泌来影响转移。此处显示 PI3K-AKT-PREAS40 信号的随后激活负责 PNA 诱导的血管内皮分泌 MCP-1 和 IL-6。因此，除了通过与肿瘤细胞相关的 MUC1 相互作用对促进肿瘤细胞扩散的影响外，循环 PNA 还可能通过增强血管内皮中促进转移的 MCP-1 和 IL-6 的分泌来影响转移。