OBJECTIVETo investigate the glycolytic phenotype of SHG44 human glioma cells under hypoxic conditions and the association between cell proliferation and apoptosis and the metabolic status.

METHODSAn 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.

RESULTSThe 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.

CONCLUSIONHypoxia 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.