Fig. 3

MB-PDT-induced cell death is independent of caspase activity. MDA-MB-231, MCF-7 and MCF-10A cells were untreated (control), only irradiated (λ), only incubated with MB (MB) or treated (MB-PDT). After 1 h, 3 h or 24 h of irradiation, cells were collected and lysed in an appropriate buffer. (a) Caspase-8, (b) caspase-3 and -7 and (c) caspase-9 activities were measured by a fluorimetric assay using a specific substrate utilizing 50 μg of total protein lysates. (n = 3 independent experiments). * p < 0.05 versus respective negative control. Results are shown as mean ± s.e.m