Meis1 regulates oxygen flux and ROS via HLF. (A) Western blots showing levels of HLF in control and Meis1-depleted MLL-AF9 knockin, and MV4;11 cells. (B) Meis1f/f MLL-AF9 knockin cells were transduced with Meis1 or FLAG-Meis1 and ChIP performed using anti-Meis1 or anti-FLAG antibodies or control IgG. The bar graph depicts fold enrichment of the various regions of the Hlf locus relative to IgG. Previously described genomic regions related to Runx1 and Flt3 were used as positive controls. A schematic of the Hlf locus with location of PCR assays is depicted. (C) Meis1f/f MLL-AF9 knockin cells were transduced with retrovirus-expressing HLF (pMY-HLF) or control (pMY). The bar graph depicts colonies formed by transduced cells cultured in the presence of vehicle or 4-OHT. *P < .01. (D) Bar graph depicting colonies formed by MLL-AF9 knockin cells transduced with NT or 4 different Hlf-shRNAs. Data are mean ± SEM. (E) Bar graph depicting proportions of Annexin V⁺ cells in MLL-AF9 knockin cells transduced with NT or Hlf-shRNA. (F) Survival curves of mice transplanted with Meis1f/f MLL-AF9 knockin leukemic cells transduced with HLF or control (pMY) retrovirus. Recipients were treated with vehicle or tamoxifen. *P < .01, log-rank test. n = 4 to 5 mice per group. (G) Histograms depicting intracellular ROS in Meis1f/f MLL-AF9 knockin cells transduced with pMY-HLF or control (pMY), treated with vehicle or 4-OHT. (H) Histogram depicting intracellular ROS in MLL-AF9 knockin cells transduced with NT or Hlf-shRNA. (I) Graph depicting OCR in Meis1f/f MLL-AF9 knockin cells transduced with HLF or control retrovirus and treated with vehicle (Veh) or 4-OHT. The arrow indicates the point at which oligomycin was added.