Shanxi Medical University, Taiyuan, China.
Department of Orthopaedics, The Second Hospital of Shanxi Medical University, Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Taiyuan, China.
FEBS J. 2018 Apr;285(7):1359-1371. doi: 10.1111/febs.14416. Epub 2018 Mar 23.
Vascular endothelial growth factor (VEGF) A and vascular endothelial growth factor receptor 1 (VEGFR1) signaling is crucial for angiogenesis and progression of osteosarcoma (OS). However, the regulation of the VEGF/VEGFR1 expression is still unclear in OS. Here, we show lower levels of miRNA-134 (miR-134) in OS tissues and cells. Induction of miR-134 overexpression significantly reduced the proliferation of Saos-2 cells and their secretion of pro-angiogenic factors, but increased the frequency of apoptotic Saos-2 cells. Treatment with conditioned medium from the cells transfected with miR-134 reduced the tube formation in human umbilical vein endothelial cells, which was abrogated by a combination of VEGF and conditioned medium. Furthermore, miR-134 significantly inhibited the growth of implanted OS tumors in vivo and attenuated the VEGFA and VEGFR1 expression and angiogenesis in the tumors. In addition, higher levels of VEGFA and VEGFR1 were detected and miR-134 inhibited the expression of VEGFA and VEGFR1 in Saos-2 cells and OS tumors. Bioinformatic analysis indicated that the 3'-UTR of VEGFA and VEGFR1 contained the motif for miR-134 binding. Co-transfection with the luciferase reporter containing the wild-type, but not the mutant, of the 3'-UTR of VEGFA or VEGFR1 together with miR-134 decreased the luciferase activity in Saos-2 cells. Finally, miR-134 dramatically inhibited AKT activation and proliferating cell nuclear antigen expression in Saos-2 cells. Collectively, these findings indicate that miR-134 is a potential tumor suppressor by targeting VEGFA/VEGFR1 signaling to attenuate the progression and angiogenesis in OS. Therefore, miR-134 may be a novel biomarker for the prognosis of OS and a target for the design of new therapies for OS.
血管内皮生长因子（VEGF）A 和血管内皮生长因子受体 1（VEGFR1）信号对于骨肉瘤（OS）的血管生成和进展至关重要。然而，VEGF/VEGFR1 表达的调节在 OS 中仍不清楚。在这里，我们显示 OS 组织和细胞中的 miRNA-134（miR-134）水平较低。诱导 miR-134 过表达显著降低了 Saos-2 细胞的增殖及其促血管生成因子的分泌，但增加了凋亡 Saos-2 细胞的频率。用转染 miR-134 的细胞的条件培养基处理减少了人脐静脉内皮细胞的管形成，而 VEGF 和条件培养基的组合则消除了这种作用。此外，miR-134 显著抑制了体内植入的 OS 肿瘤的生长，并减弱了肿瘤中的 VEGFA 和 VEGFR1 表达和血管生成。此外，检测到更高水平的 VEGFA 和 VEGFR1，并且 miR-134 抑制了 Saos-2 细胞和 OS 肿瘤中 VEGFA 和 VEGFR1 的表达。生物信息学分析表明，VEGFA 和 VEGFR1 的 3'-UTR 包含 miR-134 结合的基序。与包含野生型而不是突变型 3'-UTR 的 VEGFA 或 VEGFR1 的荧光素酶报告基因共转染与 miR-134 一起降低了 Saos-2 细胞中的荧光素酶活性。最后，miR-134 显著抑制了 Saos-2 细胞中 AKT 激活和增殖细胞核抗原表达。总之，这些发现表明，miR-134 通过靶向 VEGFA/VEGFR1 信号来抑制 OS 的进展和血管生成，是一种潜在的肿瘤抑制因子。因此，miR-134 可能是 OS 预后的新型生物标志物，也是设计 OS 新疗法的靶点。
