Fig. 8

Inhibition of Hif1α-PD-L1 axis enhances the antileukemia effect of DS-5272. a MLL-AF9;CreERT2-Hif1α-f/f leukemia cells were established as described in Fig. 4a. The leukemia cells were pretreated with EtOH or 1 μM 4OHT for 24 h and were transplanted into recipient mice. Kaplan–Meier survival curves of these leukemic mice treated with vehicle or DS-5272. (n = 6 per group). Statistical significance was evaluated by the log rank test. b (left) Cell surface expression of PD-L1 in MLL-AF9 cells transduced with non-targeting (NT) control sgRNA or PD-L1-targeting sgRNA, showing efficient knockout (KO) of PD-L1. (right) Kaplan–Meier survival curves of mice injected with control (NT) or PD-L1-depleted (PD-L1 KO) MLL-AF9 cells, that were treated with vehicle or DS-5272 (n = 10 per group). Statistical significance was evaluated by the log rank test. c Representative FACS dot plots showing cell surface expression of PD-L1 (left), and quantitation of mean fluorescence intensity (MFI) of PD-L1 (right) in Gr-1+ MLL-AF9 cells treated with DS-5272 or DS-5272 + Echinomycin. Data are shown as mean ± s.d. of three biologically independent samples. Student t-test. d Kaplan–Meier survival curves of leukemic mice treated with vehicle, DS-5272, Echinomycin, or DS-5272 + Echinomycin (Vehicle: n = 13, DS-5272: n = 9, Echinomycin: n = 6, DS-5272 + Echinomycin: n = 5). Statistical significance was evaluated by the log rank test. e Kaplan–Meier survival curves of leukemic mice treated with vehicle, anti-PD-1/PD-L1, DS-5272, or DS-5272 + anti-PD-1/PD-L1. Vehicle: n = 16, DS-5272: n = 31, anti-PD-1/PD-L1: n = 6, DS-5272 + anti-PD-1/PD-L1: n = 29. Statistical significance was evaluated by the log rank test