Fig. 1.
Resistance to cetuximab-mediated inhibition of Akt and Erk phosphorylation in cells transfected with a constitutively active H-Ras. A431 cells transfected with a control vector (A431V) or an expression vector containing constitutively active H-RasG12V (A431-Ras) were left untreated or were treated with 20 nM cetuximab for 16 h in serum-free medium. Cell lysates were prepared and analyzed for the levels of total and phosphorylated Akt, total and phosphorylated Erk, and His-tagged Ras by Western blot analysis with respective antibodies.