2.6. Mouse xenograft tumor models and treatments

Mice had three separate evaluation protocols which included pharmacokinetics, dCK activity, and growth inhibition studies. CEM cells were maintained in 10% FBS in RPMI-1640 and were grown at 37°C, 20% O₂, and 5% CO₂. CEM tumor xenografts were developed in 8–12 week-old male or female NSG mice by implanting 2 × 10⁶ CEM cells in 100 μL of a 50/50 (vol/vol) mixture of PBS and matrigel (BD Biosciences) for subcutaneous injections in left shoulders (for imaging, PK, and growth inhibition studies). DI-87 (dCKi, Sundia Pharmaceuticals) was administered by oral gavage to recipient animals. For oral administration of DI-87, the drug was solubilized in the formulation containing PEG-200: Transcutol: Labrasol: Tween-80 mixed in 5:3:1:1 ratio. For imaging studies, the mice were treated with indicated doses of DI-87 after the tumor size reached 250 mm³. For growth inhibition and pharmacokinetic studies, treatments were started after the tumors reached 50 mm³.