Fig. 7.

Apoptosis of HNSCC HTB-43 cells (closed symbols) and normal human lymphocytes (open symbols) exposed to CAP for 1 h at 37°C at 10 (diamonds) or 50 μM (squares). Apoptosis was assessed by flow cytometry with Annexin V-FITC/PI. Displayed is the mean of three experiments of 5 × 10⁴ measurements each, error bars denote standard deviation. The contour diagrams above the plot show one representative experiment out of three for each CAP concentration. The lower left quadrant of each diagrams show the viable cells, which exclude PI and are negative for Annexin V-FITC binding. The upper right quadrants contain the non-viable, necrotic cells, positive for Annexin V-FITC binding and for PI uptake. The lower left quadrants represent the apoptotic cells, Annexin V-FITC positive and PI negative, demonstrating cytoplasmic membrane integrity. The apoptosis was expressed as a ratio of the number of early and late apoptotic cells to the number of cells with no measurable apoptosis