Figure 3
Doxycycline increases the inhibitory effect of gemcitabine on cell growth and the inducing effect of gemcitabine on caspase 9 and 3/7 activities. Fibroblast, A549, A549 ρ0, COLO357 and HT29 cells were treated with vehicle or doxycycline (DC) for 5 days. During the last 2 days, cultures were not co-treated or co-treated with gemcitabine (Gem). (a) Mean number of live cells after 5 days of treatment, relative to vehicle-treated cells (n ≥ 4). (b) Percentage of dead cells relative to total cell number after 5 days of treatment (n = 4). (c) Mean caspase 9 activity after 5 days of treatment, as determined in Caspase-Glo 9 luminescence activity assays (n = 4). (d) Mean caspase 8 activity after 5 days of treatment, as determined in Caspase-Glo 8 luminescence activity assays (n = 4). (e) Mean caspase 3/7 activity after 5 days of treatment, as determined in Caspase-Glo 3/7 luminescence activity assays (n = 4). Error bars indicate standard deviations. Asterisks denote statistically significant differences (*p < 0.05; **p < 0.01).
