Abstract: Objective To investigate the glycolytic phenotype of SHG44 human glioma cells under hypoxic conditions and the
association between cell proliferation and apoptosis and the metabolic status. Methods An in vitro hypoxic cell model was
established in SHG44 cells using CoCl2. Real-time PCR and Western blotting were used to assess the expressions of
hypoxia-inducible factor-1α (HIF-1α) and the enzymes involved in glycolysis including PDK1, PKM2, and LDHA. Intracellular
ATP levels were measured by bioluminescence assay to assess the energy metabolic status of SHG44 cells. The viability and
apoptosis of the cells were examined using MTT assay and flow cytometry, respectively. Results The cells in hypoxic culture
showed obviously increased expressions of HIF-1α, LDHA, PDK1, and PKM2 at both the mRNA and protein levels as
compared to those in normal cell culture. Hypoxia of the cells also resulted in a lowered cell proliferative activity and an
increased apoptosis rate with lowered intracellular ATP concentrations and elevated mitochondrial membrane potential.
Conclusion Hypoxia can induce a glycolytic phenotype of tumor cells. The sensitivity of tumor cells to hypoxia-induced cell
death is directly correlated with their metabolic status.