Figure 4: Lysis of MCF-7 spheroid cells expressed as arbitrary units (au) of lactate dehydrogenase (LDH) activity in the culture supernatant in arbitrary units (au). Spheroids were exposed to different concentrations of ACE-NE (expressed as μg of ACE/mL) for 30 minutes (A) or 60 minutes (B), and then kept in the dark (black columns) or irradiated (λ 660 nm, 4.5 J/cm2, white columns). **p<0.01 and ***p<0.001 vs dark at the same ACE concentration.