dmPGE₂ enhances the anti-leukemia activity of dexamethasone in vivo. (A) Schematic of PDX experiment. (B) Percentage of human CD45⁺ cells in the blood of mice engrafted with a diagnostic T-ALL patient sample (DX-96) at the time of treatment. (C) qPCR analysis of NR3C1 mRNA levels in splenocytes isolated from mice treated with vehicle (N = 4), dmPGE₂ (200 μg/kg; N = 3), dexamethasone (15 mg/kg; N = 3), or the combination (dmPGE₂ + dexamethasone; N = 4) 3 hours after single treatment. (D) Representative images of spleens isolated 4 weeks after final treatment(s). (E) Weights of spleens isolated from mice treated with vehicle, dmPGE₂, dexamethasone, or the combination. (F) Total number of human CD45⁺ cells in bone marrow of mice 4 weeks after treatment. (G) Treatment effects on the survival of mice engrafted with a relapsed pediatric T-ALL sample (REL-14). Percentage of relapsed leukemic (human CD45⁺) cells in the blood of mice at the initiation of treatment. (H) Total number of human CD45⁺ leukemic cells in the blood of mice after 4 weeks of treatment. (I) Kaplan-Meier survival curves of mice transplanted with relapsed pediatric T-ALL cells (REL-14) treated with vehicle (N = 4), dexamethasone (5 mg/kg; N = 5), dmPGE₂ (200 μg/kg; N = 5), or the combination (N = 4) for 2 weeks (5 days on; 2 days off). The difference in overall survival between the treatment groups is shown. All data are represented as SEM. *P < .05, **P < .01, ***P < .001.