Variations in the fetal bovine serum and glucose concentration in the culture medium impact the viability of glioblastoma cells as evidenced through the modulation of cell cycle and reactive oxygen species: An in vitro study

Background: In vitro cell culture is essential for elucidating various signaling mechanisms and screening pharmacological agents to assess their safety and efficacy. However, cell proliferation and survival in culture can be significantly influenced by variations in the composition of the culture medium. For instance, variations in glucose and fetal bovine serum (FBS) concentrations can impact cell viability. Despite this, only a few studies have examined the impact of varied FBS and glucose concentrations in culture media on cell viability. Objective: This study investigated the mechanisms and cellular effects of glucose and FBS deprivation in glioblastoma cell lines. Methods: We systematically evaluated the impact of FBS and glucose deprivation on the proliferation and survival of rat C6 and human U-87 MG glioblastoma cell lines. Results: Glucose deprivation (0 mg/dL) significantly reduced the viability of C6 cells and moderately lowered the viability of U-87 MG cells, with partial recovery upon glucose supplementation (100 mg/dL, 400 mg/dL). Notably, FBS deprivation (0%) exerted a more profound effect, inducing the accumulation of reactive oxygen species and extensive cell death in both cell lines. Restoration of FBS (1, 2, 4, 6, 8, and 10%) recovered cell viability and reduced oxidative stress. Furthermore, both glucose and FBS deprivation altered antioxidant enzyme expression and mitochondrial function. Glucose and FBS deprivation also differentially affected protein kinase B phosphorylation, suggesting metabolic stress-induced signaling modulation. Conclusion: These findings highlight the differential responses of glioblastoma cells to glucose and FBS deprivation and underscore the importance of standardizing culture conditions, especially serum and glucose levels, when designing experiments involving glioblastoma cells.