Inhibition of HK3 decreases cell viability of ATRA-differentiated APL cells and renders APL cells more sensitive to anthracyclin therapy. (A) NB4 control (SHCOO2) or HK3 knockdown (shHK3_560, shHK3_1420, shHK3_1748) APL cells were grown in the presence or absence of 1μM ATRA for 4 or 6 days. Cell viability was measured by an Alamar Blue assay in 3 independent experiments. Cell viability is shown as percent change compared with untreated SHCOO2 control cells. **P < .005, shHK3 vs SHC002 control (Mann-Whitney U test). (B) NB4 control (SHC002) or HK3 knockdown (shHK3_560, shHK3_1420, shHK3_1748) APL cells were incubated with 0.01μM idarubicin for 48 hours (left panel) or 0.03μM doxorubicin for 72 hours (right panel), and cell viability was measured as in panel A. **P < .01; *P < .05 (Mann-Whitney U tests). (C) Caspase activation of NB4 cells treated with 0.1μM idarubicin for 24 hours (left panel) or 0.1μM doxorubicin for 48 hours (right panel) was measured by a luminescence assay. ***P < .0001 (Mann-Whitney U test).