Fig. 3.

Lipid raft disruption and loss of ErbB members by MEDICA. a AU565 cells were treated for 24 h with MEDICA as indicated. Plasma membrane ErbB2 and EGFR were determined by immunofluorescence confocal microscopy (red). Scale bar 20 μm. b AU565 cells were treated for 24 h with 200uM MEDICA. Plasma membrane ErbB members were tagged with Sulfo-NHS-Biotin and isolated by Streptavidin-Agarose beads. Plasma membrane (pm) and total ErbB members were analyzed by Western blot. c, d Lipid raft disruption by MEDICA. AU565 and BT474 cells were treated for 24 h and 40 h with 200uM MEDICA, respectively. Caveolin-1 was determined by FACS and by immunofluorescence confocal microscopy. GM1 was determined by immunofluorescence confocal microscopy. *Significant as compared to control (P < 0.05). e AU565 cells were treated for 24 h with 200 μM MEDICA. Cell fractions prepared by density gradient centrifugation were subjected to GM1 (dot blot, upper frame) and ErbB2 (Western blot, lower frame) determination. Representative blots