Department of General Surgery, Peking University First Hospital, Beijing 100034, China.
Department of Urology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang 310016, China.
Chin Med J (Engl). 2022 Oct 5;135(19):2326-2337. doi: 10.1097/CM9.0000000000002154.
Cell competition is an important feature in pancreatic cancer (PC) progression, but the underlying mechanism remains elusive. This study aims to explore the role of exosomes derived from normal pancreatic ductal epithelial cells involved in PC progression.
PC cells and pancreatic stellate cells (PSCs) were treated with exosomes isolated from pancreatic ductal epithelial cells. Cell proliferation was assessed by CCK8 assays. Cell migration and invasion were assessed by Transwell assays. PC and matched adjacent non-tumor tissue specimens were obtained from 46 patients pathologically diagnosed with PC at Peking University First Hospital from 2013 to 2017. Tissue miR-485-3p and p21-activated kinase-1 (PAK1) expression was examined by real-time polymerase chain reaction (RT-PCR), and the relationship of the two was analyzed using Pearman's product-moment correlation. The clinical significance of miR-485-3p was analyzed using the Chi-square test, Wilcoxon rank-sum test, and Fisher exact probability, respectively. The binding of miR-485-3p to PAK1 5'-untranslated region (5'-UTR) was examined by luciferase assay. PC cells were xenografted into nude mice as a PC metastasis model.
Exosomes from pancreatic ductal epithelial cells suppressed PC cell migration and invasion as well as the secretion and migration of PSCs. MiR-485-3p was enriched in the exosomes of pancreatic ductal epithelial cells but deficient in those of PC cells and PSCs, in accordance with the lower level in PSCs and PC cells than that in pancreatic ductal cells. And the mature miR-485-3p could be delivered into these cells by the exosomes secreted by normal pancreatic duct cells, to inhibit PC cell migration and invasion. Clinical data analysis showed that miR-485-3p was significantly decreased in PC tissues (P < 0.05) and was negatively associated with lymphovascular invasion (P = 0.044). As a direct target of miR-485-3p, PAK1 was found to exert an inhibitory effect on PC cells, and there was a significantly negative correlation between the expression levels of miR-485-3p and PAK1 (r = -0.6525, P < 0.0001) in PC tissues. Moreover, miR-485-3p could suppress PC metastasis in vivo by targeting p21-activated kinase-1.
Exosomal miR-485-3p delivered by normal pancreatic ductal epithelial cells into PC cells inhibits PC metastasis by directly targeting PAK1. The restoration of miR-485-3p by exosomes or some other vehicle might be a novel approach for PC treatment.
细胞竞争是胰腺癌（PC）进展的一个重要特征，但潜在机制仍难以捉摸。本研究旨在探讨源自正常胰腺导管上皮细胞的外泌体在 PC 进展中所起的作用。
用分离自胰腺导管上皮细胞的外泌体处理 PC 细胞和胰腺星状细胞（PSC）。通过 CCK8 检测评估细胞增殖。通过 Transwell 检测评估细胞迁移和侵袭。从 2013 年至 2017 年，从北京大学第一医院经病理诊断为 PC 的 46 名患者中获得 PC 及匹配的相邻非肿瘤组织标本。通过实时聚合酶链反应（RT-PCR）检测组织 miR-485-3p 和 PAK1 的表达，并使用皮尔逊积矩相关分析分析两者之间的关系。使用卡方检验、Wilcoxon 秩和检验和 Fisher 确切概率分别分析 miR-485-3p 的临床意义。通过荧光素酶测定检测 miR-485-3p 与 PAK1 5'非翻译区（5'-UTR）的结合。将 PC 细胞异种移植到裸鼠中作为 PC 转移模型。
来自胰腺导管上皮细胞的外泌体抑制了 PC 细胞的迁移和侵袭以及 PSC 的分泌和迁移。miR-485-3p 在胰腺导管上皮细胞的外泌体中富集，但在 PC 细胞和 PSC 的外泌体中缺乏，与胰腺导管细胞中的水平相比，PSCs 和 PC 细胞中的水平较低。并且，正常胰腺导管细胞分泌的外泌体可将成熟的 miR-485-3p 递送至这些细胞中，从而抑制 PC 细胞的迁移和侵袭。临床数据分析显示，miR-485-3p 在 PC 组织中明显降低（P<0.05），与血管淋巴管侵犯呈负相关（P=0.044）。作为 miR-485-3p 的直接靶标，PAK1 对 PC 细胞具有抑制作用，并且在 PC 组织中 miR-485-3p 和 PAK1 的表达水平之间存在显著的负相关（r=-0.6525，P<0.0001）。此外，miR-485-3p 通过靶向 PAK1 可在体内抑制 PC 转移。
正常胰腺导管上皮细胞分泌的外泌体递送的 miR-485-3p 通过直接靶向 PAK1 抑制 PC 转移。通过外泌体或其他载体恢复 miR-485-3p 可能是治疗 PC 的一种新方法。
