Figure 1.

Lapatinib and neratinib showed strong cytotoxic effects in feline mammary carcinoma cell lines. (A) CAT-M cell line presented higher cytotoxic effects when incubated with lapatinib (IC₅₀ = 3930 nM ± 49) than with neratinib. (B) FMCp cell line was susceptible to both lapatinib and neratinib (100% and 74.9% of cytotoxicity, respectively; IC₅₀ = 4870 nM ± 100 for lapatinib). (C) FMCm cell line also showed high cytotoxic effects in the presence of lapatinib (IC₅₀ = 17,470 nM ± 100), contrasting with the neratinib. (D) SkBR-3 cells showed a maximum cytotoxic effect of 91.1% (IC₅₀ = 16,220 nM ± 1040) after exposure to lapatinib and 66.0% when exposed to neratinib. For graphical convenience, lapatinib was represented in a µM range, while neratinib was defined in a nM range. The experiments were performed in triplicates, in three independent assays.