Baseline expression and activation levels of EGFR and COX-2 protein levels in hormone-refractory PCa cells (PC-3M and DU-145).

<p>Cells grown in 1% FBS were exposed to 0, 10 and 100 ng/mL EGF for 24 h as described in Materials and Methods. The resulting cellular proteins were subjected to SDS-PAGE and Western blot analysis to determine the protein levels of p-EGFR, EGFR and COX-2 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076169#pone-0076169-g002" target="_blank">Figure 2A</a>). Western blot for β-actin is shown as the loading control. The relative protein level for p-EGFR/EGFR and COX-2 is shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076169#pone-0076169-g002" target="_blank">Figure 2B</a>.