To further investigate a role for TACE in alcohol-mediated EGFR transactivation we used 3D microscopy of deconvoluted z-stack images (20 × 1μm) of Caco-2 or MDA-MB-231 cells to identify changes in TACE location in the cells (Figure 6Ca–d). Translocation of TACE to the apical surface from a perinuclear location is associated with EGFR transactivation and cleavage of EGFR proligands including TGF-α (Blobel, 2002, Forsyth et al., 2007). Although TACE inhibitors block EGFR activation at the 10 minute timepoint, we observed maximum translocation (surface staining) of TACE after 30 min. Therefore, we show data for 30 min in Figure 6C in which alcohol clearly stimulates translocation of TACE to the apical (Caco-2) or outer (MDA-MB-231) cell surface further supporting a specific role for TACE in alcohol transactivation of the EGFR.
