Figure 2. The combination of cetuximab with celecoxib improves the inhibition the EGFR-directed signaling pathway in colorectal cancer cells.

The phosphorylated and non-phosphorylated forms of EGFR, ERK 1/2 and AKT(Ser) were detected by Western-blot using specific antibodies. Cells were treated for 1h with cetuximab (CTX, 100 μg/ml) alone or in combination with celecoxib (CXB, 50 μM) and then treated with EGF (100 ng/mL) for 5 min. The expression level of β-actin was included as loading control. The corresponding densitometric analysis is also shown. Data are means ± SEM of three independent experiments (*p <0.05, compared with the control; # p<0.05, compared with cetuximab-treated cells).