Figure 4. Combination therapy significantly induces cell death via apoptosis and necrosis.

HOS cells were treated with vehicle control, PENAO and gefitinib as single drugs and in combination, then stained for early apopotosis (AnnV+/PI-), late (AnnV+/PI+) apoptosis and necrosis (AnnV-/PI+). (A) AnnV/PI density plot of one representative experiment comparing the treatment groups on HOS cells after 24 hours. (B) Early apoptotic, late apoptotic and necrotic cell populations in the combination treatment group were compared to the PENAO and gefitinib monotherapy groups and control group. Results are presented as a mean ± SEM of 3 experiments performed with duplicate samples. ^** p < 0.01; ^*** p < 0.001.