FTI-induced inhibition of cell viability is in part related to induction of apoptosis. (A) Agarose gel stained with ethidium bromide after electrophoresis of low-molecular-weight DNA extracted from a constant number of total marrow cells of 3 representative CML patients and from LAMA and K562 cells exposed for 48 hours to FTIs at the IC50 (CML1 to α-HFPA; CML2 to Man-A; CML3, LAMA, and K562 to SCH). (B) A representative flow cytometric detection of apoptic hypodiploid DNA peak-stained with propidium iodide derived from LAMA cells and total marrow cells of a CML patient exposed to SCH (1 μM). At least 6 × 105 events were counted per sample. Horizontal bars indicate hypodiploid DNA peak and its percentage. (C) In situ TdT assay to quantitate the number of apoptotic marrow cells from a CML patient after culture for 48 hours in absence and presence of SCH (1 μM). Darkly stained cells are apoptotic. Original magnification, × 40.
