Department of Gastroenterology, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
Medical College, Nantong University, Nantong, China.
J Cell Biochem. 2019 Jan;120(1):988-999. doi: 10.1002/jcb.27465. Epub 2018 Aug 30.
Pancreatic cancer (PC) is one of the most lethal cancers known worldwide, and its prognosis is poor in most patients. Exosomes are nanosized extracellular vesicles, which are released from various cell types. They are involved in cellular communication. The diagnosis and treatment of PC were improved substantially with exosomes. In this study, we isolated PC-derived exosomes and investigated their proteomic profile. Then, we conducted bioinformatic analysis on proteomic data. Differential ultracentrifugation was performed to isolate exosomes from human serum samples and four PC cell lines. Transmission electron microscopy and Western blot analysis were used to characterize the isolated exosomes. Liquid chromatography coupled with tandem mass spectrometry was conducted to identify the proteome of serum exosomes. Proteomic analysis demonstrated that all the serum exosomes were derived from three cohorts of human subjects; these serum exosomes contained a total of 655 proteins, out of which 315 proteins overlapped with ExoCarta database. Gene oncology and kyoto encyclopedia of genes and genomes analyses provided the functional annotation of the proteome. Interestingly, 18 or 14 proteins were upregulated and 11 or 14 proteins were downregulated in serum exosomes derived from patients with PC as compared with in serum exosomes derived from healthy volunteers or from pancreatitis patients respectively. Annexin A11, a calcium-dependent phospholipid-binding protein, was expressed in a PC cell line (CFPAC-1)-derived exosomes and in tumor tissues of patients with PC, respectively. Our data provided a basic foundation for further studies on the protein composition of PC-derived exosomes and its involvement in PC biology.
胰腺癌（PC）是全球最致命的癌症之一，大多数患者预后不良。外泌体是纳米大小的细胞外囊泡，由各种细胞类型释放。它们参与细胞间通讯。外泌体的出现极大地改善了 PC 的诊断和治疗。在本研究中，我们分离了 PC 来源的外泌体并研究了它们的蛋白质组学特征。然后，我们对蛋白质组学数据进行了生物信息学分析。通过差速超速离心法从人血清样本和 4 种 PC 细胞系中分离外泌体。透射电子显微镜和 Western blot 分析用于鉴定分离出的外泌体。采用液相色谱串联质谱法鉴定血清外泌体的蛋白质组。蛋白质组学分析表明，所有血清外泌体均来自三个人群队列；这些血清外泌体共包含 655 种蛋白质，其中 315 种蛋白质与 ExoCarta 数据库重叠。基因肿瘤学和京都基因与基因组百科全书分析为蛋白质组提供了功能注释。有趣的是，与健康志愿者或胰腺炎患者的血清外泌体相比，源自 PC 患者的血清外泌体中分别有 18 种或 14 种蛋白上调，11 种或 14 种蛋白下调。钙依赖性磷脂结合蛋白 Annexin A11 在 PC 细胞系（CFPAC-1）来源的外泌体和 PC 患者的肿瘤组织中均有表达。我们的数据为进一步研究 PC 来源的外泌体的蛋白质组成及其在 PC 生物学中的作用提供了基础。
