Department of Hematology, The Second Hospital of Hebei Medical University, Key Laboratory of Hematology, Shijiazhuang, Hebei 050000, P.R. China.
Oncol Rep. 2018 Jun;39(6):2873-2880. doi: 10.3892/or.2018.6395. Epub 2018 Apr 23.
Angiogenesis plays a significant role in the pathogenesis of multiple myeloma (MM). Microvesicles (MVs), a type of extracellular vesicles, are known as important players in cell-to-cell communication. MM-derived MVs have exhibited the activity of promoting angiogenesis. Bortezomib and lenalidomide are important drugs for treating myeloma. Therefore, the aim of the present study was to investigate whether and how MVs secreted from human myeloma cells exposed to bortezomib and lenalidomide affect angiogenesis. RPMI-8226 human myeloma cells and human umbilical vein endothelial cells (HUVECs) were used. MVs were isolated from the drug-treated RPMI-8226 cells. The number of the MVs were analyzed with flow cytometry. The expression of pro-angiogenic factors was analyzed with PCR and ELISA. The angiogenic potential of HUVECs was examined. NF-κB activation was analyzed using PCR, immunofluorescent staining and western blotting assays. We showed that bortezomib treatment induced an increase in the number of MVs shed from myeloma cells, but the number of MVs was not significantly altered by lenalidomide. The expression levels of vascular endothelial growth factor (VEGF), interleukin 6 (IL-6) and basic fibroblast growth factor (bFGF) were reduced in the MVs from the RPMI-8226 cells exposed to bortezomib and lenalidomide. Consequently, these MVs exhibited reduced angiogenic potential, as evaluated by wound healing tests, Boyden chamber assays and tube formation assays. Co-culturing HUVECs with drug-treated MVs inhibited NF-κB activation in the HUVECs and reduced the secretion of pro-angiogenic factors. In conclusion, bortezomib and lenalidomide treatment of cultured myeloma cells can block MV-induced angiogenesis and hence provides another mechanism for anti-angiogenic therapy.
血管生成在多发性骨髓瘤（MM）的发病机制中起着重要作用。微泡（MVs）是一种细胞外囊泡，被认为是细胞间通讯的重要参与者。MM 来源的 MV 具有促进血管生成的活性。硼替佐米和来那度胺是治疗骨髓瘤的重要药物。因此，本研究旨在探讨骨髓瘤细胞暴露于硼替佐米和来那度胺后分泌的 MV 是否以及如何影响血管生成。使用 RPMI-8226 人骨髓瘤细胞和人脐静脉内皮细胞（HUVEC）。从药物处理的 RPMI-8226 细胞中分离 MV。用流式细胞术分析 MV 的数量。用 PCR 和 ELISA 分析促血管生成因子的表达。检测 HUVEC 的血管生成潜能。用 PCR、免疫荧光染色和 Western blot 分析 NF-κB 激活。结果表明，硼替佐米处理诱导骨髓瘤细胞释放的 MV 数量增加，但来那度胺对 MV 的数量没有明显影响。暴露于硼替佐米和来那度胺的 RPMI-8226 细胞来源的 MV 中血管内皮生长因子（VEGF）、白细胞介素 6（IL-6）和碱性成纤维细胞生长因子（bFGF）的表达水平降低。因此，这些 MV 的血管生成潜力降低，通过划痕愈合试验、Boyden 室试验和管形成试验评估。将 HUVEC 与药物处理的 MV 共培养可抑制 HUVEC 中 NF-κB 的激活，并减少促血管生成因子的分泌。总之，培养骨髓瘤细胞的硼替佐米和来那度胺治疗可阻断 MV 诱导的血管生成，从而为抗血管生成治疗提供了另一种机制。
