Longitudinal PDX Leukemia Monitoring

All animal experiments were performed with the approval of Dana-Farber Cancer Institute’s Institutional Animal Care and Use Committee (IACUC). NOD.Cg-Prkdc^scidIl2rg^tm1Sug/JicTac (NOG) mice were obtained from Taconic Biosciences (Rensselaer, NY, USA). Non-irradiated 8–12 weeks old adult mice were transplanted with previously established patient-derived xenografts (PDXs) (25 (link)) via tail vein injection (250,000 cells/mouse). Engraftment of human cells (hCD45⁺) was analyzed and monitored longitudinally by weekly bleeding to quantify hCD45⁺ cells in the peripheral blood by flow cytometry with human CD45-PE and anti-mouse CD45-APC-Cy7 antibodies (Biolegend, San Diego, CA, USA). Mice were monitored closely to detect disease onset and treatment started when hCD45⁺ cells were detectable in the peripheral blood. Mice were randomly assigned to either normal or 0.1% VTP-50469 rodent special diet (25 (link)). Mice were bled weekly to monitor leukemia burden as described above and euthanized when showing clinical signs of disease (experimental endpoint). Leukemia cells from a subset of these animals were harvested after seven days of treatment to perform RNA-Seq.