Leukemia Transplantation and Subcutaneous Tumor Model

For the leukemia transplantation model sublethally irradiated C;129S4-Rag2^{tm1.1Flv Il2rgtm1.1Flv}/J knockout mice (JAX stock #014593) [24 (link)] were injected with 1 × 10⁵ MOLM-13 cells expressing control shRNA or CSF2RB shRNA and luciferase into their tail veins. BLI measurements were performed using the IVIS200 imaging system (Xenogen) after intraperitoneal injection of luciferin (150 mg/kg; BioSynth, Staat, Switzerland). Data were quantified with Living Image Software (Xenogen). For subcutaneous tumor model C;129S4-Rag2^{tm1.1Flv Il2rgtm1.1Flv}/J knockout mice were subcutaneously injected with 5 × 10⁶ MOLM-13 cells expressing control shRNA or CSF2RB shRNA into their right flanks. Tumor size was measured by a caliper and calculated as described here [25 (link)]. Tumor weight was measured after sacrificing the mice on day 17. Staining was performed using antibodies against phospho-STAT5 (see above) or CSF2RB (Abcam, Cambridge, UK).