Figure 1.

Talaporfin (NPe6)-mediated photodynamic therapy (NPe6-PDT) induced proapoptotic Bcl-2 associated X protein (Bax) activation and caspase-dependent/independent cell death in glioblastoma (GBM) cells. (a) Human GBM cell lines T98G and U343MG were subjected to vehicle treatment (control), NPe6 treatment (μg·mL⁻¹), laser treatment, or NPe6-PDT, as shown in the figure (see the Materials and Methods for detailed treatments). After 24 h, the mortality rate of the treated cells was assayed by the dye exclusion assay. (b) T98G and U343MG cells were subjected to vehicle treatment (control), NPe6-PDT (NPe6, 15 μg mL⁻¹), or 5-fluorouracil (5-FU, 500 μM) treatment with or without z-VAD-FMK (a pan-caspase inhibitor; 100 μM) pretreatment for 2 h before laser irradiation (Figure 1A), as shown in the figure. After 24 h of laser irradiation, the mortality rate was assayed as described in the Materials and Methods. (c) T98G and U343MG cells were subjected to NPe6-PDT at the indicated NPe6 dose with pretreatment using vehicle or z-VAD-FMK (100 μM), as shown in the figure. After 24 h, the relative proportion of the mortality rates of z-VAD-FMK-sensitive and -insensitive cells in total cell death rate were calculated as described in the Materials and Methods. (d) T98G and U343MG cells were subjected to vehicle treatment (control), NPe6 treatment (15 μg·mL⁻¹), laser treatment, or NPe6-PDT (NPe6 15 μg·mL⁻¹), as shown in the figure. After 24 h, the cell lysates were subjected to in vitro protein crosslinking assay as described in the Materials and Methods, followed by immunoblotting using a primary antibody against Bax.