Role of ER Stress Response in Photodynamic Therapy: ROS Generated in Different Subcellular Compartments Trigger Diverse Cell Death Pathways
Figure 5
(A) Cells loaded with EG-porphyrin derivatives were pre-treated with Ru360 (5 µM 4T1, 4 µM HL60) for 1 h to inhibit Ca2+ mitochondrial uptake. After irradiation the cells were further incubated in medium and their viability was determined 24 h later by the trypan blue exclusion method. The percentage of dead cells was expressed as the mean ± SD (n = 3–6). **P<0.01, ***P<0.001 represents statistical differences between PDT-treated cells vs. PDT-treated cells in the presence of Ru360. (B) Cells were preincubated for 1 h with Ru360 (4–5 µM) and 2 h post-irradiation the cytosolic, mitochondrial and nuclear extracts were prepared and analyzed by Western blotting with specific antibody recognizing cytochrome c, GAPDH and PARP. Results are representatives of at least three experiments.