INA-UV treatment induces apoptosis. INA-UV treatment of MCF7 cells induces mitochondrial membrane depolarization (DiOC6 staining), phosphatidyl serine exposure (Annexin V binding) and DNA fragmentation (TUNEL assay). MCF7 cells treated with increasing amounts of INA and irradiated with UV were stained with DiOC6 (A) or Annexin V (B). The percentage of the population with low DiOC6 staining (depolarized mitochondria) or high Annexin V staining (PS exposure on the cell surface) were determined by FACS analysis and plotted as a function of the INA used for the treatment. Data are mean ± S.D. Representative graphs from two independent experiments are presented. C. Histograms corresponding to the TUNEL staining of MCF7 cells treated with different amounts of INA and irradiated with UV.