MV-NIS promotes radioiodine uptake in infected medulloblastoma cells. Radionuclide uptake assays were performed with A. UW426 and B. D283med. Each cell line was infected with MV-NIS or MV-GFP (MOI of 0.1) and then exposed to 1 × 105 cpm of 125I at 24, 48 or 72 hours post infection. Due to excessive cell death at 72 hours, only data from the 24 and 48 hour timepoints are shown. The addition of KClO4 to the cells effectively blocked incorporation of 125I. Each sample was run in triplicate, with error bars representing one standard deviation. +/− denotes the presence or absence of KClO4 respectively. C. Radioiodine kinetics in UW426 and D283med 48 hours after MV-NIS infection. Efflux of 125I is rapid, with a t1/2 retention time of approximately 1.5 minutes for each cell line. Data points are the average of four independent samples. D. Medulloblastoma xenografts incorporate 131I following MV-NIS infection. The mouse in the left panels received a 2 × 105 TCID50 intratumoral injection of MV-NIS three days following tumor implantation whereas the mouse in the right panels was given an equal volume of OptiMEM to serve as a vehicle control. Tumor bioluminescence was visualized 48 hours later, and the mice were subsequently given an IP injection of 37 MBq 131I. Cherenkov luminescence from the irradiated tumors was then visualized the following day.