Evaluation of the cytotoxic activity of human recombinant TRAIL and control His peptide on K562.
Dose-dependent effect of TRAIL on cell viability evaluated by trypan blue dye exclusion (A) and on apoptosis quantitatively evaluated by flow cytometry after PI staining (B) are shown. Cells were cultured for 24 hours with the indicated concentrations of TRAIL or with His control peptide (1 μg/mL). Data represent the means ± SDs of 5 independent experiments performed in duplicate. In panel A, data are expressed as percentage of untreated control cells. In panel C, the cell cycle was evaluated by PI DNA staining and flow cytometry. The insets show the percentage of cells with a G1(2n), S, G2/M(4n) DNA content, calculated excluding apoptotic cells (Apo). A representative analysis of 4 separate experiments is shown. Panel D shows the percentage of cells incorporating BrdU, evaluated by flow cytometry, in samples left untreated or treated for 16 hours with TRAIL or His peptide. Data represent the means ± SDs of 3 separate experiments performed in duplicate.
