This investigation was designed to assess the effect of DuP-697 on growth and apoptosis in a human chronic myeloid leukemia (CML) cell line (K562 cells) and primary CML cells from CML patient bone marrow. DuP-697 significantly suppressed K562 cells and primary CML cells growth and induced apoptosis in a concentration-dependent manner and the growth-inhibiting effect was independent on Philadelphia chromosome. The IC50 of DuP-697 at 36 h was 31.7 muM. It arrested G1-S phase transmit on cell cycle and its apoptosis activity was partially abrogated by pretreating K562 cells with Z-IETD-fmk, a specific inhibitor of caspase-8. This study suggested that Dup-697 suppresses growth and induces apoptosis on K562 leukemia cells by cell-cycle arrest and caspase-8 activation.