FIGURE 3.

In vitro selectivity of EGFR × c-MET bsAbs in comparison with cetuximab. A, EBC-1 as a tumor model cell line with high to moderate c-MET and EGFR expression and T47D as an epithelial model cell line with low EGFR expression and no c-MET expression were mixed in a ratio of 1:30. To distinguish the two cell lines, EBC-1 cells were stained with the green membrane dye PKH2. The cell mixture was incubated with 30 nm bsAb or cetuximab and subjected to flow cytometric analysis. Antibody binding was detected by PE-labeled anti-human Fc secondary antibody. Representative dot plots for green versus yellow fluorescence are shown. B, in vitro selectivity was defined as the ratio of mean fluorescence intensity of the EBC-1 and the T47D cell population. Displayed are means with S.D. of two independent experiments. Asterisks, significant difference of groups in comparison with the selectivity of cetuximab (***, p < 0.001, with one-way analysis of variance with Dunnett's test). Error bars, S.D.