Zhu Tingzhun, Li Xiaoming, Luo Lihan, Wang Xiaogang, Li Zhiqing, Xie Peng, Gao Xu, Song Zhenquan, Su Jingyuan, Liang Guobiao
Department of Neurosurgery, General Hospital of Shenyang Military Area Command, No. 83, Wenhua Road, Shenhe District, Shenyang, 110840, China.
Health Care Centre, Shenyang Entry-Exit Inspection and Quarantine Bureau, Shenyang, China.
J Transl Med. 2015 Nov 12;13:356. doi: 10.1186/s12967-015-0727-2.
Glioblastoma is the most common and lethal type of primary brain tumor. β-Elemene, a natural plant drug extracted from Curcuma wenyujin, has shown strong anti-tumor effects in various tumors with low toxicity. However, the effects of β-elemene on malignant phenotypes of human glioblastoma cells remain to be elucidated. Here we evaluated the effects of β-elemene on cell proliferation, survival, stemness, differentiation and the epithelial-to-mesenchymal transition (EMT) in vitro and in vivo, and investigated the mechanisms underlying these effects.
Human primary and U87 glioblastoma cells were treated with β-elemene, cell viability was measured using a cell counting kit-8 assay, and treated cells were evaluated by flow cytometry. Western blot analysis was carried out to determine the expression levels of stemness markers, differentiation-related molecules and EMT-related effectors. Transwell assays were performed to further determine EMT of glioblastoma cells. To evaluate the effect of β-elemene on glioblastoma in vivo, we subcutaneously injected glioblastoma cells into the flank of nude mice and then intraperitoneally injected NaCl or β-elemene. The tumor xenograft volumes were measured every 3 days and the expression of stemness-, differentiation- and EMT-related effectors was determined by Western blot assays in xenografts.
β-Elemene inhibited proliferation, promoted apoptosis, impaired invasiveness in glioblastoma cells and suppressed the growth of animal xenografts. The expression levels of the stemness markers CD133 and ATP-binding cassette subfamily G member 2 as well as the mesenchymal markers N-cadherin and β-catenin were significantly downregulated, whereas the expression levels of the differentiation-related effectors glial fibrillary acidic protein, Notch1, and sonic hedgehog as well as the epithelial marker E-cadherin were upregulated by β-elemene in vitro and in vivo. Interestingly, the expression of vimentin was increased by β-elemene in vitro; this result was opposite that for the in vivo procedure. Inhibiting β-catenin enhanced the anti-proliferative, EMT-inhibitory and specific marker expression-regulatory effects of β-elemene.
β-Elemene reversed malignant phenotypes of human glioblastoma cells through β-catenin-involved regulation of stemness-, differentiation- and EMT-related molecules. β-Elemene represents a potentially valuable agent for glioblastoma therapy.
胶质母细胞瘤是最常见且致命的原发性脑肿瘤类型。β-榄香烯是一种从温郁金中提取的天然植物药物，已在多种肿瘤中显示出强大的抗肿瘤作用且毒性较低。然而，β-榄香烯对人胶质母细胞瘤细胞恶性表型的影响仍有待阐明。在此，我们评估了β-榄香烯在体外和体内对细胞增殖、存活、干性、分化以及上皮-间质转化（EMT）的影响，并研究了这些作用的潜在机制。
用β-榄香烯处理人原发性和U87胶质母细胞瘤细胞，使用细胞计数试剂盒-8法检测细胞活力，并用流式细胞术对处理后的细胞进行评估。进行蛋白质免疫印迹分析以确定干性标志物、分化相关分子和EMT相关效应分子的表达水平。进行Transwell实验以进一步确定胶质母细胞瘤细胞的EMT。为了评估β-榄香烯在体内对胶质母细胞瘤的作用，我们将胶质母细胞瘤细胞皮下注射到裸鼠侧腹，然后腹腔注射氯化钠或β-榄香烯。每3天测量肿瘤异种移植体积，并通过蛋白质免疫印迹分析确定异种移植中干性、分化和EMT相关效应分子的表达。
β-榄香烯抑制胶质母细胞瘤细胞的增殖，促进其凋亡，损害其侵袭能力，并抑制动物异种移植瘤的生长。干性标志物CD133和ATP结合盒亚家族G成员2以及间充质标志物N-钙黏蛋白和β-连环蛋白的表达水平显著下调，而β-榄香烯在体外和体内均上调了分化相关效应分子胶质纤维酸性蛋白、Notch1和音猬因子以及上皮标志物E-钙黏蛋白的表达水平。有趣的是，β-榄香烯在体外增加了波形蛋白的表达；这一结果与体内实验相反。抑制β-连环蛋白增强了β-榄香烯的抗增殖、EMT抑制和特异性标志物表达调节作用。
β-榄香烯通过β-连环蛋白参与调节干性、分化和EMT相关分子，逆转了人胶质母细胞瘤细胞 的恶性表型。β-榄香烯是一种对胶质母细胞瘤治疗具有潜在价值的药物。
