Zhang XiaoYan, Sheng YouMing, Li BingWei, Wang Qin, Liu XueTing, Han JianQun
Laboratory of Microvascular Biopathology, Institute of Microcirculation, Chinese Academy of Sciences, Peking Union Medical College, Beijing, China.
Microhemodynamics Laboratory, Institute of Microcirculation, Chinese Academy of Sciences, Peking Union Medical College, Beijing, China.
Cell Biochem Funct. 2021 Mar;39(2):308-316. doi: 10.1002/cbf.3583. Epub 2020 Sep 2.
Cancer cell derived exosomes play important roles in cancer progression and modulation of the tumour microenvironment. This study aims to investigate the role of prokineticin receptor 1 (PKR1) positive exosomes on angiogenesis. In the present study, PKR1 expression in tumour samples from ovarian cancer patients were examined firstly. Then, two ovarian cancer cell lines, namely A2780 and HO-8910 cells, were used to isolate and obtain the PKR1 positive exosomes from the serum free medium. The function analysis of PKR1 positive exosomes on angiogenesis was conducted by cell proliferation and migration assay, tube formation analysis, and tumour volume assay. The results showed that PKR1 expression was down regulated in tumour samples of ovarian cancer patients compared with adjacent normal tissues. The intracellular expression of PKR1 could be detected in A2780 and HO-8910 cells. And, the isolated exosomes from the serum free medium were confirmed by transmission electron microscopic and NTA analysis, as well as the co-presence of PKR1 with exosome marker CD63. The function analysis of PKR1 positive exosomes on angiogenesis demonstrated the uptake of PKR1 positive exosomes by human umbilical vein endothelial cells through immunofluorescence staining. The angiogenesis assays in vitro indicated that PKR1 positive exosomes promoted migration and tube formation of HUVECs but not proliferation. The endogenous PKR1 was also verified to help to enhance migration and promote tube formation of vascular endothelial cells, which might involved in the phosphorylation of STAT3. Additionally, The tumour volume from exosomes treated A2780 tumour-bearing mice was significantly increased compared with the control group, accompanied with the induced PKR1 expression and phosphorylation of STAT3 level. SIGNIFICANCE OF THE STUDY: This study proved the important role of PKR1 positive exosomes released from ovarian cancer cells on promoting angiogenesis. The data indicated that PKR1 derived from ovarian cancer cells could act as an important tumour associated antigen and biomolecular factor for cellular communication in tumour microenvironment.
癌细胞衍生的外泌体在癌症进展和肿瘤微环境调节中发挥重要作用。本研究旨在探讨促动力蛋白受体1（PKR1）阳性外泌体在血管生成中的作用。在本研究中，首先检测了卵巢癌患者肿瘤样本中PKR1的表达。然后，使用两种卵巢癌细胞系，即A2780和HO - 8910细胞，从无血清培养基中分离并获得PKR1阳性外泌体。通过细胞增殖和迁移测定、管腔形成分析和肿瘤体积测定对PKR1阳性外泌体在血管生成中的功能进行分析。结果显示，与相邻正常组织相比，卵巢癌患者肿瘤样本中PKR1表达下调。在A2780和HO - 8910细胞中可检测到PKR1的细胞内表达。并且，通过透射电子显微镜和NTA分析以及PKR1与外泌体标志物CD63的共存在，证实了从无血清培养基中分离的外泌体。通过免疫荧光染色对PKR1阳性外泌体在血管生成中的功能分析表明，人脐静脉内皮细胞摄取了PKR1阳性外泌体。体外血管生成测定表明，PKR1阳性外泌体促进了人脐静脉内皮细胞的迁移和管腔形成，但不促进增殖。还证实内源性PKR1有助于增强血管内皮细胞的迁移并促进管腔形成，这可能与STAT3的磷酸化有关。此外，与对照组相比，用外泌体处理的A2780荷瘤小鼠的肿瘤体积显著增加，同时伴有PKR1表达的诱导和STAT3水平的磷酸化。研究意义：本研究证明了卵巢癌细胞释放的PKR1阳性外泌体在促进血管生成中的重要作用。数据表明，源自卵巢癌细胞的PKR1可作为肿瘤微环境中细胞通讯的重要肿瘤相关抗原和生物分子因子。
