Effect of ST1346 and ST1707 on the ATRA-dependent induction of NBT-reducing activity and inhibition of NB4 cell growth.

NB4 cells were seeded (200 000/mL) and treated for 3 days with the indicated concentrations of ST1346 and ST1707 in the presence of vehicle (○) or ATRA (0.1μM) (●) for 3 days. Aliquots of cells were used for the determination of NBT-reducing activity (A,D), total number of cells (B,E), and cell viability (C,F). The results shown are the means ± SD of 3 separate cultures. *Significantly higher than the corresponding group treated with vehicle (P < .01 according to the Student t test). °Significantly higher than the sum of the effects observed in the corresponding ST1346-, ST1707-, and ATRA-treated groups, following 2-way analysis of variance and measurement of the F score of the interaction (P < .01 according to Tukey test).