Figure 1.

Comparison of sensitivity of breast cancer cell lines to MEK inhibitor CI1040. Forty-six basal or luminal breast cancer cell lines were treated with increasing doses of CI1040 and cell viability was assessed at 0 h (time of drug addition) and at 72 h after treatment. GI₅₀ was calculated from the dose-response curves as described in Materials and Methods. Data are presented as GI₅₀ (mol/L) of cell lines in the order of most sensitive to most resistant (from left to right). Red and green columns, basal and luminal cellular phenotype, respectively. All data for GI₅₀, TGI, and LC₅₀ for CI1040 and U0126 response of cell lines are summarized in Supplementary Table S1.