ATF-SAP activity on fibroblasts and MDA-MB-231 cancer cell line. (A) Molecular profile of skin and bladder-derived fibroblasts. Human skin- and bladder-derived primary fibroblasts were analyzed by immunofluorescence for the expression of Fibroblasts Surface Antigen (SFA) and alpha-Smooth Muscle Actin (αSMA). ECV304 epithelial bladder cancer cell line was used as negative control. Nuclei were stained with DAPI (blue). (B) uPAR expression on skin and bladder-derived fibroblasts as well as breast cancer MDA-MB-231 cell line was analyzed by flow cytometry and expressed as histogram plots (upper panel) and Relative Fluorescence Intensity (RFI) (see “Materials and Methods”) (lower panel). The dashed line represents the threshold arbitrarily defining positive expression (RFI = 2). (C) ATF-SAP toxic activity was evaluated after 72 h incubation and compared to the untargeted seed SAP. Results from one representative experiment are shown as mean ± SD. Three independent experiments were performed for each assay.