MUC4 up-regulates EGFR family receptors and induces downstream Erk1/2 and PKC-γ pathways.

<p>(<b>A</b>) Immunoblot analyses showed reduced expression of EGFR, ErbB2, and ErbB3 in MUC4 knockdown cells compared with control cells. (<b>B</b>) Reduced expression (using immunoblot) of Sprouty 2 was detected in MUC4 knockdown cell when compared with control cells. (<b>C</b>) Immunoblot showed that reduced phosphorylation of Erk1/2 and expression of PKC-γ in MUC4 knockdown cells compared with control cells. β-actin was used as a loading control. (<b>D</b>) Immunoblot analyses showed reduced expression of β-catenin and its target gene product cyclin D1in MUC4 knockdown compared with control cells.