Liang Chen, Yang Ling, Guo Shi-Wen, Li Rui-Chun
Department of Neurosurgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
Department of Aeromedical Physical Examination, Xi'an Civil Aviation Hospital, Xi'an, 710082, China.
Curr Med Sci. 2022 Apr;42(2):397-406. doi: 10.1007/s11596-022-2517-4. Epub 2022 Feb 24.
This study aimed to investigate the effects of downregulating astrocyte elevated gene-1 (AEG-1) expression combined with all-trans retinoic acid (ATRA) on vasculogenic mimicry (VM) formation and angiogenesis in glioma.
U87 glioma cells were transfected with AEG-1 shRNA lentiviral vectors (U87-siAEG-1) and incubated in a medium containing 20 µmol/L ATRA. Matrigel-based tube formation assay was performed to evaluate VM formation, and the cell counting kit-8 (CCK-8) assay was used to analyze the proliferation of glioma cells in vitro. Reverse transcription-quantitative polymerase chain reaction and Western blot analysis were used to investigate the mRNA and protein expression of related genes, respectively. Glioma xenograft models were generated via subcutaneous implantation of glioma cells in nude mice. Tumor-bearing mice received an intraperitoneal injection of ATRA (10 mg/kg per day). Immunohistochemistry was used to evaluate the expression of related genes and the microvessel density (MVD) in glioma xenograft models. CD34/periodic acid-Schiff double staining was performed to detect VM channels in vivo. The volume and weight of tumors were measured, and a tumor growth curve was drawn to evaluate tumor growth.
A combination of ATRA intervention and downregulation of AEG-1 expression significantly inhibited the proliferation of glioma cells in vitro and glioma VM formation in vitro and in vivo. It also significantly decreased MVD and inhibited tumor growth. Further, the expression levels of matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial-cadherin (VE-cadherin), and vascular endothelial growth factor (VEGF) in glioma significantly decreased in vivo and in vivo.
Hence, a combinatorial approach might be effective in treating glioma through regulating MMP-2, MMP-9, VEGF, and VE-cadherin expression.
本研究旨在探讨下调星形胶质细胞上调基因-1（AEG-1）表达联合全反式维甲酸（ATRA）对胶质瘤血管生成拟态（VM）形成及血管生成的影响。
用AEG-1短发夹RNA慢病毒载体（U87-siAEG-1）转染U87胶质瘤细胞，并在含20 μmol/L ATRA的培养基中培养。采用基质胶管形成实验评估VM形成，并用细胞计数试剂盒-8（CCK-8）实验分析胶质瘤细胞的体外增殖情况。分别采用逆转录定量聚合酶链反应和蛋白质印迹分析来研究相关基因的mRNA和蛋白质表达。通过将胶质瘤细胞皮下接种于裸鼠建立胶质瘤异种移植模型。荷瘤小鼠腹腔注射ATRA（每天10 mg/kg）。采用免疫组织化学法评估胶质瘤异种移植模型中相关基因的表达及微血管密度（MVD）。进行CD34/过碘酸希夫双重染色以检测体内VM通道。测量肿瘤的体积和重量，并绘制肿瘤生长曲线以评估肿瘤生长情况。
ATRA干预与AEG-1表达下调相结合显著抑制了胶质瘤细胞的体外增殖以及体内外胶质瘤VM的形成。它还显著降低了MVD并抑制了肿瘤生长。此外，胶质瘤中基质金属蛋白酶（MMP）-2、MMP-9、血管内皮钙黏蛋白（VE-钙黏蛋白）和血管内皮生长因子（VEGF）的表达水平在体内外均显著降低。
因此，联合治疗方法可能通过调节MMP-2、MMP-9、VEGF和VE-钙黏蛋白的表达来有效治疗胶质瘤。
