Knockdown of ACC1 promotes migration and invasion of U251 glioma cells by epigenetically suppressing SDH.

Glioma is a common and aggressive malignant brain tumor. Despite advances in research, the mechanisms driving glioma initiation and progression remain incompletely understood. The present study aimed to assess the role of acetyl‑CoA carboxylase 1 (ACC1) in glioma, focusing on its mechanistic function in U251 cells and its clinical significance. ACC1 expression was first assessed in four glioma cell lines and then the effects on cellular functions were evaluated. Based on the finding that ACC1 knockdown altered the phenotype of U251 cells, potentially through modulation of succinate dehydrogenase (SDH) activity, further mechanistic assessments were performed. Finally, the association between ACC1 expression and patient prognosis was analyzed. The results demonstrated that ACC1 overexpression inhibited proliferation, migration and invasion in U87 cells. Conversely, ACC1 knockdown promoted these processes in U251, T98G and LN229 cells. Mechanistically, in U251 cells, ACC1 knockdown increased acetyl‑CoA levels, enhancing substrate availability for P300. This led to upregulation of DNA methyltransferase 1 (DNMT1), hypermethylation of the SDH promoter and subsequent SDH downregulation. The resulting increase in reactive oxygen species (ROS) levels promoted U251 cell migration and invasion. Analysis of clinical data revealed a significant correlation between low ACC1 expression and poor survival outcomes in patients with glioma. These findings suggest that ACC1 functions as a tumor suppressor in glioma. Its downregulation promotes a pro‑tumorigenic phenotype via the acetyl‑CoA/P300/DNMT1/SDH/ROS pathway, highlighting its potential as a prognostic marker and therapeutic target. This underscores the importance of developing personalized treatment strategies targeting ACC1 in glioma.