Combined Effects of Atorvastatin and Glucose Deprivation on Metabolic Stress and Lipid-Raft Disruption in Glioblastoma and Breast Cancer Cells

Background/Objectives: Atorvastatin, a lipophilic HMG-CoA reductase inhibitor used for lipid lowering, also exhibits considerable anti-neoplastic activity. Although previous studies have shown that glucose starvation can potentiate several anticancer chemotherapies, atorvastatin has not been rigorously investigated for its impact on metabolic vulnerabilities and the effects on cholesterol-rich lipid rafts in aggressive tumors. This work aims to evaluate the combined anticancer activity of atorvastatin with metabolic interventions, specifically glucose starvation, on U-87 (glioblastoma) and MDA-MB-231 (triple-negative breast cancer) cell lines. Methods: U-87 and MDA-MB-231 cancer cells were cultured in either normal or glucose-free media and treated with different concentrations of atorvastatin. The impact of atorvastatin on these cancer cells was analyzed by examining cell viability, apoptosis, cell cycle, and changes in membrane order within lipid rafts. Results: This study found that glucose starvation increased the sensitivity of U-87 cells to atorvastatin by lowering IC50 values and eliciting arrest in the G1 phase of the cell cycle. MDA-MB-231 cells were less dependent on glucose for viability; however, atorvastatin consistently induced S-phase arrest across both metabolic states. Additionally, atorvastatin induced apoptosis in both U-87 and MDA-MB-231 cells, with the effect being more pronounced and dose-dependent in the fasting state with glucose. Interestingly, both Caspase-3 and Caspase-9 were consistently downregulated by atorvastatin in U-87 cells, regardless of the fasting state, corresponding to the induction of cell cycle arrest. Membrane lipid rafts exhibited decreased membrane order under glucose starvation, which was further decreased in response to atorvastatin in both cell lines, indicating a reduction in cholesterol. Conclusions: These results demonstrate that atorvastatin exhibits anticancer activity, characterized by both contextual and metabolic targeted effects, including a reduction in cancer proliferation, the triggering of cell cycle arrest via the downregulation of caspase pathways, and a decrease in membrane order. Notably, the combined activity of combining antilipemic agents with glucose-fasting provides potential metabolic strategies that could help create more effective and personalized approaches to cancer treatment.