Fig. 3.

Effect of cetuximab and trastuzumab on the anti-proliferation of tumor cells expressing EGFR and/or HER-2. Expression of intracellular Ki-67, an indicator of cell proliferation, was analyzed within the target cells by flow cytometry 96 h after culture with cetuximab or trastuzumab treatment to investigate its inhibitory effect on the proliferation of canine tumor cells expressing EGFR and/or HER-2. The control groups were treated with media alone or human IgG isotype control antibody. a Representative flow cytometry data of intracellular Ki-67 expression. The data are representative of four independent experiments, each tested in triplicate. b The frequency of Ki-67-expressing cells within target tumor cells 96 h after culture with trastuzumab and cetuximab treatment. The values represent the means ± standard deviation (SD). The data are representative of four independent experiments, each tested in triplicate