Effects of epidermal growth factor and its signal transduction inhibitors on apoptosis in human colorectal cancer cells

Figure 3 Expression of phosphorylated EGF receptor (EGF-R) with the molecular weight of 145 kDa visualized by Western blotting (A) and quantitated by an image analysis system (B) after incubation of SW480 cells with 0. 6 mL/L dimethyl sulfoxide (DMSO, the control group), 225 ng/mL (37.5 nmol/L) EGF in 0.6 mL/L DMSO, 225 ng/mL EGF + 2.5 μg/mL (17 nmol/L) EGF antibody in 0.6 mL/L DMSO, or 225 ng/mL EGF + 215 ng/mL (0.8 μmol/L) tyrphostin 51 in 0.6 mL/L DMSO serum-free medium for 48 h. Samples were pooled from 7 independent experiments (n = 7). Density was calibrated by an internal control, α-tubulin (55 kDa).