CD437-dependent apoptosis in primary cultures of freshly isolated APL blasts, as assessed by the TUNEL assay. Freshly isolated APL blasts (300,000/mL) from patient 2 (Table 1) were treated with vehicle (DMSO), alone (Control; A and B), or with CD437 (10−6 mol/L; C) for 60 hours. The panels show flow cytometric TUNEL analyses with forward scatter on the horizontal axis and fluorescence intensity on the vertical axis. (A) Negative control for the TUNEL assay, showing the level of background fluorescence in samples treated with fluorescent dUTP in the absence of TdT. The results shown were obtained on an aliquot of the control culture, but similar results were obtained on an aliquot of the CD437 culture (not shown). The percentage of apoptotic, necrotic, and viable cells is indicated on the top-right, bottom-left, and bottom-right, respectively.
