Synergistic Inhibitory Effects of Cetuximab and Cisplatin on Human Colon Cancer Cell Growth via Inhibition of the ERK-Dependent EGF Receptor Signaling Pathway

Figure 5

Reversed effect of an ERK inhibitor on the combination treatment-induced cell growth inhibition and downregulation of AP-1 and NF-κB activity. HCT116 and SW480 cells were preincubated with 20 μM of U0126 (an ERK inhibitor) or 20 μM SB203580 (a p38 MAPK inhibitor) for 1 h, followed by incubation with a combination of cetuximab and cisplatin for 24 h. (a) Cell growth changes were determined by MTT assay. (b) HCT116 and SW480 cells were preincubated with 20 μM of U0126 for 1 h, followed by incubation with a combination of cetuximab and cisplatin for 1 h. The activation of AP-1 and NF-κB was determined by EMSA. indicates statistically significant differences from the control. indicates statistically significant differences from the cetuximab-cisplatin combination treatment.

(a)

(b)