Figure 3

Caspase activation in human glioblastoma cells. Cultured human glioblastoma GBM8401 (a) and U-87MG (b) cells were treated with CM or mycelial fermentation (MF) for 6 h at 2 mg/ml, followed by lysate collection, protein quantification, and subsequent luminometrical detection for activities of caspase-3, caspase-8, and caspase-9. Caspase activity readings were normalized by total protein. The representative data in arbitrary luminescent unit are shown as mean±S.D. from three independent experiments. *P<0.05, as compared with control group. (c) Both glioblastoma cells were pretreated either with Asp-Met-Gln-Asp-fluoromethyl ketone (Z-DEVD-FMK), Leu-Glu-His-Asp-fluoromethyl ketone (Z-IETD-FMK), or Ile-Glu-Thr-Asp-fluoromethyl ketone (Z-LEHD-FMK) peptides at 20 μM for 1 h to block caspase-3, caspase-8, and caspase-9 activity, respectively, or with equivalent dimethylsulfoxide (DMSO) for solvent control. The cell viability after 24 h of MF treatment was determined by MTT assay. The representative data are shown as mean±S.D. from three independent experiments. *P<0.05, as compared with DMSO solvent control group. NC, negative control