Direct transfection of miR-137 mimics is more effective than DNA demethylation of miR-137 promoter to augment anti-tumor mechanisms of delphinidin in human glioblastoma U87MG and LN18 cells
Direct transfection of miR-137 mimics is more effective than DNA demethylation of miR-137 promoter to augment anti-tumor mechanisms of delphinidin in human glioblastoma U87MG and LN18 cells
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DOI：
10.1016/j.gene.2015.07.034
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发表时间：
2015-11-15
期刊：
影响因子：
3.5
通讯作者：
Ray, Swapan K.
中科院分区：
文献类型：
--
作者：
Chakrabarti, Mrinmay;Ray, Swapan K.
胶质母细胞瘤是人类最致命的脑肿瘤。最近的研究表明，5-aza-2-脱氧胞苷（AzaC）可以通过间接增加肿瘤抑制因子microRNA-137 （miR-137）的表达来抑制人胶质母细胞瘤干细胞的细胞周期进展。Delphinidin （DPN）是一种新的花青素，可以抑制不同癌症细胞的生长。我们研究了间接或直接过表达miR-137后再进行DPN治疗对胶质母细胞瘤生长的抑制作用。在人胶质母细胞瘤U87MG和LN18细胞中，10 μ M AzaC和50 μ M DPN联合治疗对细胞生长的抑制作用最高。甲基化敏感聚合酶链反应（MS-PCR）结果显示，AzaC抑制miR-137启动子区域的甲基化，导致miR-137表达间接增加，而miR-137启动子区域在两种胶质母细胞瘤细胞系中都是高甲基化的。我们的研究结果还表明，直接转染miR-137模拟物和DPN处理后，miR-137模拟物和DPN处理联合对细胞侵袭的抑制作用最大，因为在与人微血管内皮细胞共培养的人胶质母细胞瘤细胞中，血管生成因子（VEGF）的表达最少，从而阻止了血管生成网络的形成。这种组合策略最有效地抑制了生存因子（p-Akt和NF-kappa B）、血管生成因子（VEGF和B - fgf）、生长因子受体（EGFR）和侵袭因子（MMP-9和MMP-2）。直接过表达miR-137最有效地增强了DPN通过激活外在和内在途径诱导细胞凋亡的功效。因此，序贯miR-137过表达和DPN治疗可能是抑制人胶质母细胞瘤细胞生长的一种有希望的联合治疗方法。(C) 2015 Elsevier B.V.版权所有
Glioblastoma is the deadliest brain tumor in humans. Recent studies suggested that 5-aza-2-deoxycytidine (AzaC) could inhibit cell cycle progression in human glioblastoma stem cells by an indirect increase in expression of the tumor suppressor microRNA-137 (miR-137). Delphinidin (DPN), a new anthocyanidin, inhibits cell growth in different cancers. We investigated inhibition of glioblastoma growth after indirect or direct overexpression of miR-137 and then DPN treatment. The highest inhibition of cell growth occurred due to treatment with combination of 10 mu M AzaC and 50 pM DPN in human glioblastoma U87MG and LN18 cells. The methylation sensitive-polymerase chain reaction (MS-PCR) results showed that AzaC inhibited methylation of miR-137 promoter region, which was hypermethylated in both glioblastoma cell lines, to cause indirect increase in miR-137 expression. Our results also indicated the highest miR-137 expression after direct transfection of miR-137 mimics and DPN treatment Combination of miR-137 mimics transfection and DPN treatment caused the highest inhibition of cell invasion and prevented angiogenic network formation due to the least expression of angiogenic factor (VEGF) in human glioblastoma cells in co-culture with human microvascular endothelial cells. This combination strategy most effectively inhibited survival factors (p-Akt and NF-kappa B), angiogenic factors (VEGF and b-FGF), growth factor receptor (EGFR), and invasive factors (MMP-9 and MMP-2). Direct overexpression of miR-137 most effectively augmented efficacy of DPN to induce apoptosis with activation of extrinsic and intrinsic pathways. So, sequential miR-137 overexpression and DPN treatment could be a promising combination treatment to inhibit growth of human glioblastoma cells. (C) 2015 Elsevier B.V. All rights reserved.