Figure 5

SEM ×4000 (bar 2 μm). Caco-2 and inserts (×8000) (bar 1 μm). a. untreated cells. A large number of microvilli are evident. The cellular boundaries do not appear. Insert: long microvilli are present. b. EGF treated cells. A lot of vesicles are evident. Insert: a small number of microvilli are present. c. 10 nmol/L cetuximab treated cells. The microvilli diminish in number and lose their erect position. Insert: microvilli make contacts forming a star morphology. d. 10 nmol/L cetuximab plus 10 nM EGF treated cells. Same morphology as 10 nmol/L cetuximab treated cells. e. 1 μmol/L gefitinib treated cells. The microvilli diminish in number and lose their erect position. Insert: microvilli make contacts forming a star morphology. f. 1 μmol/L gefitinib plus 10 nM EGF treated cells. Same morphology as 1 μmol/L gefitinib treated cells.