Effects of C3G on the interaction among ErbB2, FAK, cSrc and p130Cas. MCF7ErbB2 cells were treated with ethanol (0 or 400 mg/dl) with/without C3G (10, 20 or 40 μM) for 48 h. Cells were plated on fibronectin-coated culture wells. A: After 1 h of attachment on fibronectin, cell lysates were collected and immunoprecipitated (IP) with an anti-ErbB2 antibody, then immunoblotted (IB) with either an anti-FAK or anti-ErbB2 antibody. B: After 3 h of attachment, cell lysates were IP with an anti-cSrc antibody and IB with either an anti-p130Cas, FAK or cSrc antibody. C and D: The association between ErbB2 and FAK (panel A) and the association between FAK and p130Cas (panel B) was quantified by densitometry. * denotes a statistically significant difference from untreated controls. # denotes a significant difference from ethanol-treated groups. ε denotes a significant difference from ethanol- and C3G (10 μM)-treated groups. δ denotes a significant difference from ethanol- and C3G (20 μM)-treated groups. E: After 3 h of attachment, cell lysates were IP with an anti-p130Cas antibody and IB with either an anti-FAK or anti-p130Cas antibody. The experiment was replicated three times.