Fig. 4

HHT plus Ara-C induced synthetic lethality in AML. A, CI at the ED₇₅ (Fa = 0.75) of HHT plus Ara-C at different doses of 4:1, 1:2, 1:4 and 1:8 (M/M) for 24 h in HL-60, THP-1, MOLM-13 and U937 cells, where CI values < 0.9, 0.9–1.1 and > 1.1 indicate synergism, additive and antagonism, respectively. B, HL-60 cells treated with the combination of 10 nM, 20 nM, or 30 nM HHT and 40 nM, 80 nM, or 120 nM Ara-C at a fixed ratio of 1:4 for 24 h were examined by AO-EB staining. *, P < 0.05; ***, P < 0.001. C, The apoptosis of HL-60 cells treated with the combination of 30 nM HHT and 120 nM Ara-C at a fixed ratio of 1:4 for 24 h was determined by Annexin V/PI staining. D, E, Protein regulation of HL-60 and THP-1 cells treated with HHT plus Ara-C for 24 h