Objective: To investigate the effects of ACC1 knockdown on human glioma U251 cell migration and its molecular mechanisms. Methods: Human glioma U251 cell line was used. The experiment was carried out in three steps. Experiment 1: knockdown of ACC1 in U251 cells (shACC1) and its control (NC) U251 cells were established by transfection of shACC1 lentivirus and negative control virus. The cell migration was detected by Transwell migration assay and scratch test. Western blot (WB) was performed to detect the levels of ACC1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug proteins. Experiment 2: RT-qPCR and WB were performed to verify the RNA-seq result, upregulation effect of ACC1 knockdown on PAI-1 in U251 cells. The cells then were treated with PAI-1 inhibitor PAI-039, and the cell migration was detected by Transwell migration assay and scratch assay. The protein levels of ACC1, PAI-1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug were examined by WB. Experiment 3: the molecular mechanisms of knocking down ACC1 to increase PAI-1 were explored. The cells were treated with acetyltransferase inhibitor C646, and cell migration was examined by Transwell migration assay and scratch assay. WB was conducted to test the levels of ACC1, H3K9ac, PAI-1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug proteins. Each experiment was repeated three times. Results: Experiment 1: lentivirus transfection was performed on glioma U251 cells. Compared with NC group, the expression level of ACC1 in shACC1 group was decreased significantly, indicating that lentivirus transfection was successful (P＜0.01), and the number of migrated cells in shACC1 group was increased significantly (P＜0.01). Migration-related proteins Vimentin, Fibronectin, N-cadherin and Slug were up-regulated, while E-cadherin was down-regulated (P＜0.01). Experiment 2: Compared with NC group, PAI-1 mRNA level in shACC1 group was up-regulated. Compared with control group, cell migration in shACC1+PAI-039 group was decreased (P＜0.01), and migration-related proteins Vimentin, Fibronectin, N-cadherin, and Slug were up-regulated. E-cadherin expression was down-regulated (P＜0.01). Experiment 3: Compared with NC group, the concentration of acetyl-coA and the expression level of H3K9ac in shACC1 group were increased significantly (P＜0.01); After further treatment with histone acetyl transferase inhibitor C646, PAI-1 mRNA level was decreased, cell migration number and H3K9ac expression level were decreased in shACC1+C646 group compared with control group (P＜0.01). Migration-related proteins Vimentin, Fibronectin, N-cadherin and Slug were up-regulated, while E-cadherin was down-regulated (P＜0.01). Conclusion: Knockdown of ACC1 promotes the migration of human glioma U251 cells by increasing histone acetylation which elevates the level of PAI-1.
目的: 探讨敲低ACC1对人胶质瘤U251细胞迁移的作用及机制。方法: 选用人胶质瘤U251细胞系。实验分为三部分,实验一:通过慢病毒转染建立稳定低表达ACC1的U251细胞株(shACC1)及其对照(NC),Transwell迁移及划痕实验检测细胞迁移,WB检测ACC1、Vimentin、Fibronectin、N-cadherin、E-cadherin、Slug蛋白表达;实验二:探索并验证敲低ACC1后下游关键分子PAI-1表达量升高。应用其抑制剂PAI-039处理细胞,Transwell迁移及划痕实验检测细胞迁移,WB检测ACC1、PAI-1、Vimentin、Fibronectin、N-cadherin、E-cadherin、Slug蛋白表达;实验三:探索敲低ACC1调节PAI-1的分子机制,检测细胞乙酰辅酶A水平及组蛋白H3乙酰化。使用乙酰基转移酶抑制剂C646处理细胞,Transwell迁移及划痕实验检测细胞迁移,WB检测ACC1、H3K9ac、PAI-1、Vimentin、Fibronectin、N-cadherin、E-cadherin、Slug蛋白表达,RT-qPCR检测PAI-1 mRNA水平;每项实验重复三次。结果: 实验一:对胶质瘤U251细胞进行慢病毒转染,WB结果显示,与NC组相比,shACC1组ACC1表达水平显著降低,提示慢病毒转染成功(P＜0.01),shACC1组迁移细胞数明显增多(P＜0.01),迁移相关蛋白Vimentin、Fibronectin、N-cadherin、Slug表达上调,E-cadherin表达下调(P＜0.01);实验二:与NC组相比,shACC1组PAI-1 mRNA水平上调;进一步使用PAI-1的抑制剂PAI-039,与对照组相比,shACC1+PAI-039组细胞迁移数减少,且呈浓度依赖性(P＜0.01),迁移相关蛋白Vimentin、Fibronectin、N-cadherin、Slug表达上调,E-cadherin表达下调(P＜0.01);实验三:与NC组相比,shACC1组乙酰辅酶A浓度显著增加(P＜0.01),H3K9ac表达水平明显升高(P＜0.01);进一步使用组蛋白乙酰基转移酶抑制剂C646处理细胞后,PAI-1 mRNA水平下降,与对照组相比,shACC1+C646组细胞迁移数减少,且呈浓度依赖性(P＜0.01),H3K9ac表达水平降低,迁移相关蛋白Vimentin、Fibronectin、N-cadherin、Slug表达上调,E-cadherin表达下调(P＜0.01);结论: 敲低ACC1通过增加组蛋白乙酰化修饰水平上调PAI-1促进人胶质瘤U251细胞的迁移。.
Keywords: ACC1; PAI - 1; cell culture; glioma; histone acetylation; migration.