...telomerase inhibition using BIBR1532 resulted in a considerable growth suppressive effect in APL-derived NB4 cells, as the most sensitive cell line, mostly through p21-mediated G1 arrest coupled with a caspase-3-dependent apoptosis via suppression of NF-κB. Moreover, the resulting data showed that combination of BIBR1532 and ATRA produced synergistic anticancer effects in mutant p53-expressing NB4 cells.