Figure 2. Cobalt complex 2 induces autophagy and autophagic cell death in cancer cells.

(A) Cobalt complex 2 does-dependently induced autophagy in HeLa cancer cells. HeLa cells treated with DMSO or indicated concentrations of cobalt complex 2 for 24 h were fixed and visualized for endogenous LC3-II expression by fluorescence microscopy using LC3-II antibody plus TRITC-conjugated anti-mouse secondary antibody. ***P < 0.001. Data were mean value ± S.D of three independent experiments. (B) Cobalt complex 2 induced LC3-II conversion in HeLa cancer cells. HeLa cells were treated with DMSO, or indicated concentrations of cobalt complex 2 for 24 h. Cell lysates were harvested and analyzed by Western blot for LC3 conversion (LC3-I, 18 kDa; LC3-II, 16 kDa) and β-actin. (C) Cytotoxicity of cobalt complex 2 in Atg7^+/+ wild-type and Atg7^−/− deficient MEFs. Atg7^+/+ wild-type and Atg7^−/− deficient MEFs were incubated with cobalt complex 2 for 72 h, MTT assay was performed to determine their cytotoxicity. The IC₅₀ values shown on the chart are mean values of three independent experiments.