Cao Jiang, Li Li, Han Xiao, Cheng Hai, Chen Wei, Qi Kunming, Chen Chong, Wu Qingyun, Niu Mingshan, Zeng Lingyu, Xu Kailin
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China,
Department of Gastroenterology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Onco Targets Ther. 2019 Jan 8;12:433-441. doi: 10.2147/OTT.S190146. eCollection 2019.
miR-302 cluster has been reported as a tumor suppressor in many human cancers; yet, its function in chronic myeloid leukemia (CML) tumorigenesis remains largely unclear. The study was aimed to explore the functional roles of miR-302 cluster in CML progression.
Quantitative reverse transcriptase PCR and Western blot were performed to evaluate miR-302 cluster and vascular endothelial growth factor A (VEGFA) expression levels. Cell Counting Kit-8 assay, colony formation assay and human umbilical vein endothelial cell line capillary tube formation were used to determine the influence of miR-302 cluster on the growth and angiogenesis of K562 cells, respectively. Luciferase reporter assay was employed to confirm the direct target interaction between miR-302 cluster and VEGFA.
This study demonstrated that miR-302 cluster was frequently downregulated in CML samples and cell lines and high level of miR-302 cluster was significantly associated with good prognosis of CML patients. Compared with miRNA negative control, miR-302 cluster mimics obviously suppressed cell growth, colony formation and angiogenesis. Further studies revealed that VEGFA was a direct target gene of miR-302 cluster. Moreover, overexpression of VEGFA dramatically abated the inhibition of miR-302 cluster on cell growth and angiogenesis.
The present study, for the first time, identified miR-302 cluster as a tumor suppressor, and overexpression of miR-302 cluster inhibited growth and angiogenesis in K562 cells. miR-302 cluster may be a potential therapeutic target in CML to develop the adjuvant antiangiogenic therapy based on VEGFA.
miR-302簇在许多人类癌症中被报道为肿瘤抑制因子；然而，其在慢性髓性白血病（CML）肿瘤发生中的作用仍不清楚。本研究旨在探讨miR-302簇在CML进展中的功能作用。
采用定量逆转录PCR和蛋白质免疫印迹法评估miR-302簇和血管内皮生长因子A（VEGFA）的表达水平。分别使用细胞计数试剂盒-8法、集落形成试验和人脐静脉内皮细胞系毛细管形成试验来确定miR-302簇对K562细胞生长和血管生成的影响。采用荧光素酶报告基因检测法来证实miR-302簇与VEGFA之间的直接靶向相互作用。
本研究表明，miR-302簇在CML样本和细胞系中经常下调，miR-302簇的高水平与CML患者的良好预后显著相关。与miRNA阴性对照相比，miR-302簇模拟物明显抑制细胞生长、集落形成和血管生成。进一步研究表明，VEGFA是miR-302簇的直接靶基因。此外，VEGFA的过表达显著减弱了miR-302簇对细胞生长和血管生成的抑制作用。
本研究首次将miR-302簇鉴定为肿瘤抑制因子，miR-302簇的过表达抑制了K562细胞的生长和血管生成。miR-302簇可能是CML中基于VEGFA开发辅助抗血管生成疗法的潜在治疗靶点。
