Mouse Mammary Tumor Virus Promoter-Containing Retroviral Promoter Conversion Vectors for Gene-Directed Enzyme Prodrug Therapy are Functional in Vitro and in Vivo
Figure 4
CYP2B1 expression, activity, and virus titers of 2GP19Talf amphotropicretroviral packaging cells stably transfected with pPCCMm1. (a) Expression of CYP2B1 in 2GP19Talf/pPCCMm1 cells. Cell lysates (equal amounts of protein)were analyzed by Western blotting for the presence of CYP2B1 using ananti-CYP2B1 antibody. The CYP2B1 band is indicated with an arrow. The molecular weights of the proteinstandard are given on the left side. Neg. cntrl.: 2GP19Talf cells not transfected with pPCCMm1. (b) Enzymatic activity of CYP2B1 in 2GP19Talf/pPCCMm1 cells. The enzymatic activity as determinedby a resorufin assay is shown as the relative emission intensity of the createdproduct resorufin at 590 nm in comparison to nontransfected cells (neg. cntrl.). (c) Virus titers of 2GP19Talf/pPCCMm1 cells asdetermined by counting the numbers of colonies of infected G418-resistant CRFKcells (colony-forming units per milliliter; CFU/mL). Two independent infectionexperiments were performed. Plating of dilutions of cells after infection wasperformed in triplicates, each. Neg. cntrl.: 2GP19Talf cells not transfected with pPCCMm1.
