Figure 4.

Total amount of 5-FC imported into Toca 511-infected tumors. Tumor cells that had been maximally transduced with Toca 511 vector were cultured with different concentrations of 5-FC for 24 hr, and intra- and extracellular 5-FC and 5-FU were measured by liquid chromatography–mass spectrometry (LC-MS). Shown are the 24 hr total intracellular import of 5-FC versus starting 5-FC levels (n = 2, error bars represent standard error of the mean). 5-FC import was determined by the sum of intracellular 5-FC and total (intra- and extracellular) 5-FU levels.