Fig. 6. TOPFLASH assays in colorectal cancer cells transfected with APC constructs. SW480 or HCT116 cells were transfected with APC constructs as indicated, and relative luciferase:Renilla values were determined as in Figure 4. (A and C) GFP-tagged APC constructs, compared with a GFP control; relative expression levels of constructs in (A) are shown underneath (western blots probed with anti-GFP; this antibody is less sensitive than anti-M-APC, so does not permit detection of full-length APC under these conditions). (B) APC constructs with various tags as indicated, and a vector control (containing HA). Note that the GFP derivatives produce generally lower TOPFLASH values than the HA- and Flag-tagged constructs, so have to be compared with the GFP control, and with GFP-tagged APC (see also A).