Clk1-regulated aerobic glycolsis is involved in glioma chemoresistance
Clk1-regulated aerobic glycolsis is involved in glioma chemoresistance
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Clk1调节的有氧糖酵解参与神经胶质瘤化疗耐药
DOI：
10.1111/jnc.14096
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发表时间：
2017
影响因子：
4.7
通讯作者：
Zheng Long Tai
中科院分区：
文献类型：
--
作者：
Zhang Li;Yang Huicui;Zhang Wenbin;Liang Zhongqin;Huang Qiang;Xu Guoqiang;Zhen Xuechu;Zheng Long Tai
化疗耐药仍然是神经胶质瘤治疗的主要挑战。在这项研究中，我们研究了时钟 1 (Clk1) 的作用，它编码一种酶，该酶是神经胶质瘤体外化疗耐药中泛醌生物合成所必需的。结果显示，Clk1在对1,3Bis(2-氯乙基)1亚硝基脲(BCNU)最敏感的GL261小鼠胶质瘤细胞中高表达，而在BCNU耐药细胞如胶质瘤干细胞、T98G、U87MG和U251胶质瘤细胞中低表达。 GL261胶质瘤细胞中Clk1的敲低显着减少了BCNU或顺铂诱导的细胞凋亡，而增殖活性和多药耐药相关基因（包括MDR1、O6-甲基鸟嘌呤-DNA甲基转移酶和GSTP1）的表达没有改变。当 Clk1 在 Clk1 敲低的 GL261 胶质瘤细胞中重新表达时，BCNU 敏感性恢复。机制研究表明，GL261 胶质瘤细胞中 Clk1 的敲低会增加有氧糖酵解，包括高葡萄糖消耗、乳酸产生和糖酵解相关基因的上调。抑制糖酵解可以逆转 GL261 细胞中 Clk1 敲低引起的化疗耐药性。此外，Clk1 的敲低诱导 GL261 胶质瘤细胞中 HIF-1α 的表达，发现这是由 AMP 激活蛋白激酶（AMPK）/雷帕霉素机械靶点（mTOR）信号通路介导的。二甲双胍和雷帕霉素均可逆转 Clk1 敲低的 GL261 神经胶质瘤细胞的化疗耐药性。 Clk1的过表达显着增加了T98G或U251人胶质母细胞瘤细胞对BCNU的敏感性，并伴有乳酸分泌减少、HIF-1α表达减少、AMPK激活和mTOR通路抑制。糖酵解的抑制或 AMPK 的激活不会改变变异神经胶质瘤细胞系中的 Clk1 表达，表明有氧糖酵解不是神经胶质瘤细胞中 Clk1 表达的上游事件。综上所述，我们的结果首次揭示线粒体 Clk1 通过 AMPK/mTOR/HIF-1α 介导的糖酵解途径调节神经胶质瘤细胞的化疗耐药性。
Chemoresistance remains a major challenge for the treatment of glioma. In this study, we investigated the role of Clock 1 (Clk1), which encodes an enzyme that is necessary for ubiquinone biosynthesis in glioma chemoresistancein vitro. The results showed that Clk1 was highly expressed in GL261 mouse glioma cells which were most sensitive to 1,3Bis (2‐chloroethyl) 1 nitrosourea (BCNU) while was low expressed in BCNU resistant cells such as glioma cancer stem cells, T98G, U87MG and U251 glioma cells. Knockdown of Clk1 in GL261 glioma cells significantly reduced BCNU‐ or cisplatin‐induced cell apoptosis, whereas the proliferative activity and the expression of multidrug resistance‐related genes including MDR1, O6‐methylguanine‐DNA methyltransferase, and GSTP1 were not changed. When Clk1 was re‐expressed in Clk1 knockdown GL261 glioma cells, the BCNU sensitivity was restored. The mechanistic study revealed that knockdown of Clk1 in GL261 glioma cells increased aerobic glycolysis including high glucose consumption, lactate production, and up‐regulation of glycolysis‐associated genes. Inhibition of glycolysis can reverse the chemoresistance elicited by Clk1 knockdown in GL261 cells. Moreover, knockdown of Clk1 induced HIF‐1α expression in GL261 glioma cells which was found to be mediated by AMP‐activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR) signaling pathway. Both metformin and rapamycin reversed the chemoresistance of Clk1 knockdown GL261 glioma cells. Over‐expression of Clk1 significantly increased the sensitivity of T98G or U251 human glioblastoma cells to BCNU which was accompanied by decreased lactate secretion, decreased expression of HIF‐1α, AMPK activation, and inhibition of mTOR pathway. Inhibition of glycolysis or activation of AMPK did not alter Clk1 expression in variant glioma cell lines suggesting that aerobic glycolysis is not an upstream event of Clk1 expression in glioma cells. Taken together, our results revealed, for the first time, that mitochondrial Clk1 regulated chemoresistance in glioma cells through AMPK/mTOR/HIF‐1α mediated glycolysis pathway.