Suppressive Effect of Chemically Induced Hypoxia on Glioblastoma Cell Proliferation

Glioblastoma is a tumor characterized by pronounced hypoxia. Hypoxia produces diverse effects on tumor cells, and the results of experimental studies available so far are contradictory. In vitro hypoxia can be modeled in two ways: by reducing the level of atmospheric oxygen (physically induced hypoxia) or by using hypoxia-inducing chemicals such as cobalt chloride (II) (CoCl₂) (chemically induced hypoxia). In the present work, we analyzed the effect of CoCl₂ on the viability, proliferation, and apoptosis of cells of three glioblastoma cell lines: 1321N1, T98g, and U373 MG. It was shown that CoCl₂ induced a dose-dependent decrease in cell viability and proliferation, and at high concentrations (200 and 400 μM) stimulated cell death. CoCl₂ had no effect on the cytotoxic activity of doxorubicin in two cell lines T98g and U373 MG, and enhanced the effect of the chemotherapeutic agent on the 1321N1 cell line, though no synergistic cytotoxic effect of the two agents was observed.