Figure 1. Characterization of the FAP construct and chemoresistant tumor cell lines.

(A) The cDNA encoding the entire murine FAP, verified by nucleotide sequencing, was inserted into the EcoRI site of the pFap vector. (B) Protein expression was demonstrated by Western blotting after transient transfection of CT26 and D2F2 cells. (C) CT26 colon and D2F2 breast carcinoma cells were treated with various chemotherapeutic agents at the concentrations indicated. After 48 hours of incubation, nuclear apoptosis was assessed by staining with Hoechst 33342 dye. Staurosporine was used as a positive control. P_CMV, human cytomegalovirus immediate-early promoter/enhancer; BGHpA, bovine growth hormone polyadenylation signal; f1 ori, f1 origin; SV40 ori, SV40 early promoter and origin; neomycin, neomycin (G418) resistance gene; SV40pa, SV40 polyadenylation signal; pUC, pUC-derived origin; ampicillin, ampicillin resistance gene (β-lactamase).