C-Terminal Binding Protein 1 Modulates Cellular Redox via Feedback Regulation of MPC1 and MPC2 in Melanoma Cells.
C-Terminal Binding Protein 1 Modulates Cellular Redox via Feedback Regulation of MPC1 and MPC2 in Melanoma Cells.
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C 端结合蛋白 1 通过黑色素瘤细胞中 MPC1 和 MPC2 的反馈调节来调节细胞氧化还原。
DOI：
10.12659/msm.912735
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发表时间：
2018-10-25
期刊：
影响因子：
--
通讯作者：
Shi Z
中科院分区：
文献类型：
--
作者：
Deng Y;Li H;Yin X;Liu H;Liu J;Guo D;Shi Z
最近的研究表明，转录辅阻遏物，C-末端结合蛋白1（CtBP 1），连接的代谢变化的转录控制的增殖，EMT，基因组的稳定性，代谢，和寿命，但CtBP 1是否影响细胞的氧化还原稳态是未知的。本研究旨在探讨CtBP 1介导的转录抑制机制，有助于代谢重编程。敲低小鼠MEF细胞和人黑素瘤细胞中的CtBP 1改变细胞氧化还原稳态。此外，进行染色质免疫沉淀（ChIP）和荧光素酶报告基因测定，以鉴定CtBP 1下游靶点，丙酮酸载体1和2基因（MPC 1和MPC 2），其有助于氧化还原稳态并受CtBP 1转录调控。此外，用糖酵解抑制剂2-脱氧-D-葡萄糖（2-DG）阻断细胞NADH水平拯救了MPC 1和MPC 2表达。采用MTT法和划痕法检测MPC 1和MPC 2的表达对黑色素瘤细胞恶性特性的影响。这些数据表明，CtBP 1直接结合到MPC 1和MPC 2的启动子上，并在转录上抑制它们，导致细胞质和细胞核中游离NADH水平的增加，从而正向反馈CtBP 1的功能。因此，在人肿瘤细胞中恢复MPC 1和MPC 2减少游离NADH并抑制黑素瘤细胞增殖和迁移。我们的数据表明，MPC 1和MPC 2是连接CtBP 1介导的转录调节到NADH产生的主要介质。CtBP 1除了作为NADH传感器之外还作为NADH调节剂的发现表明CtBP 1处于肿瘤代谢和转录控制的中心。
Recent studies have illustrated that the transcription co-repressor, C-terminal binding protein 1 (CtBP1), links the metabolic alterations to transcription controls in proliferation, EMT, genome stability, metabolism, and lifespan, but whether CtBP1 affects the cellular redox homeostasis is unexplored. This study was designed to investigate the mechanism of CtBP1-mediated transcription repression that contributes to the metabolic reprogramming. Knockdown of CtBP1 in both mouse MEF cells and human melanoma cells changed cell redox homeostasis. Further, chromatin immunoprecipitation (ChIP) and luciferase reporter assay were performed for identification of CtBP1 downstream targets, pyruvate carrier 1 and 2 genes (MPC1 and MPC2), which contribute to redox homeostasis and are transcriptionally regulated by CtBP1. Moreover, blockage of the cellular NADH level with the glycolysis inhibitor 2-Deoxy-D-Glucose (2-DG) rescued MPC1 and MPC2 expression. MTT assay and scratch assay were performed to investigate the effect of MPC1 and MPC2 expression on malignant properties of melanoma cells. The data demonstrated that CtBP1 directly bound to the promoters of MPC1 and MPC2 and transcriptionally repressed them, leading to increased levels of free NADH in the cytosol and nucleus, thus positively feeding back CtBP1’s functions. Consequently, restoring MPC1 and MPC2 in human tumor cells decreases free NADH and inhibits melanoma cell proliferation and migration. Our data indicate that MPC1 and MPC2 are principal mediators that link CtBP1-mediated transcription regulation to NADH production. The discovery of CtBP1 as an NADH regulator in addition to being an NADH sensor shows that CtBP1 is at the center of tumor metabolism and transcription control.