Cheng Cheng, Zhang Zhicai, Cheng Fuli, Shao Zengwu
Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
Department of Pediatric Orthopedics, Zhengzhou Orthopaedics Hospital, Henan University, Zhengzhou 450052, People's Republic of China.
Onco Targets Ther. 2020 Apr 20;13:3291-3301. doi: 10.2147/OTT.S244652. eCollection 2020.
Exosomes derived from cancer cells can alter the microenvironment and enhance cancer malignancy through the regulation of peripheral cell functions. The present study focused on the crosstalk between chondrosarcoma cells and human umbilical vein endothelial cells (HUVECs) mediated by exosomes derived from chondrosarcoma cells and aimed to explore the potential molecular mechanism.
Chondrosarcoma cell-derived exosomes were isolated and characterized. Cell proliferation assay, tube formation assay and transwell migration assay were performed to characterize the effects of exosomes on HUVECs. The lncRNA microarray was used to select differentially expressed lncRNAs in HUVECs treated with or without exosomes. Serum samples of patients with chondrosarcoma were collected to analyze the correlation between the RAMP2-AS1 level and the clinicopathological features. Online databases were used to predict the target microRNA of RAMP2-AS1. Dual luciferase reporter assay, Western blotting and qRT-PCR assays were performed to verify the interactions among RAMP2-AS1, miR-2355-5p and VEGFR2. Rescue experiments were conducted to validate the existence of the RAMP2-AS1/miR-2355-5p/VEGFR2 axis.
The exosomes secreted by chondrosarcoma cells could enhance HUVECs proliferation, migration and tube formation. LncRNA microarray analysis revealed that exosomes carried lncRNA RAMP2-AS1, and further verification showed that the level of RAMP2-AS1 was increased in the serum of chondrosarcoma patients and was closely related to local invasiveness, distant metastasis and poor prognosis. Subsequent experiments demonstrated that RAMP2-AS1 knockdown could partly abrogate the promoting effects on angiogenesis induced by exosomes derived from chondrosarcoma cells. Moreover, dual luciferase reporter assay and rescue experiments suggested that the RAMP2-AS1/miR-2355-5p/VEGFR2 axis was responsible for exosome-induced angiogenesis of HUVECs.
Chondrosarcoma cell-derived exosomes carry lncRNA RAMP2-AS1, which acts as a ceRNA of miR-2355-5p to regulate VEGFR2 expression, thereby positively regulating the angiogenic ability of HUVECs. Thus, exosomal RAMP2-AS1 has the potential as a novel biomarker and therapeutic target for chondrosarcoma.
癌细胞来源的外泌体可通过调节外周细胞功能改变微环境并增强癌症恶性程度。本研究聚焦于软骨肉瘤细胞来源的外泌体介导的软骨肉瘤细胞与人类脐静脉内皮细胞（HUVECs）之间的相互作用，旨在探索潜在的分子机制。
分离并鉴定软骨肉瘤细胞来源的外泌体。进行细胞增殖实验、管腔形成实验和Transwell迁移实验以表征外泌体对HUVECs的影响。使用lncRNA芯片筛选经外泌体处理和未处理的HUVECs中差异表达的lncRNAs。收集软骨肉瘤患者的血清样本以分析RAMP2-AS1水平与临床病理特征之间的相关性。利用在线数据库预测RAMP2-AS1的靶标微小RNA。进行双荧光素酶报告基因检测、蛋白质免疫印迹和qRT-PCR实验以验证RAMP2-AS1、miR-2355-5p和VEGFR2之间的相互作用。进行拯救实验以验证RAMP2-AS1/miR-2355-5p/VEGFR2轴的存在。
软骨肉瘤细胞分泌的外泌体可增强HUVECs的增殖、迁移和管腔形成能力。lncRNA芯片分析显示外泌体携带lncRNA RAMP2-AS1，进一步验证表明RAMP2-AS1在软骨肉瘤患者血清中的水平升高，且与局部侵袭、远处转移和预后不良密切相关。随后的实验表明，敲低RAMP2-AS1可部分消除软骨肉瘤细胞来源的外泌体对血管生成的促进作用。此外，双荧光素酶报告基因检测和拯救实验表明RAMP2-AS1/miR-2355-5p/VEGFR2轴介导了外泌体诱导的HUVECs血管生成。
软骨肉瘤细胞来源的外泌体携带lncRNA RAMP2-AS1，其作为miR-2355-5p的竞争性内源RNA调节VEGFR2表达，从而正向调节HUVECs的血管生成能力。因此，外泌体RAMP2-AS1有潜力成为软骨肉瘤的新型生物标志物和治疗靶点。
