Effects of knockdown ACC1 on glioma U251 cell migration and its mechanisms

Abstract

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.