Fig. 2: Effects of anti-HER2 treatments in HER2-E breast cancer cell lines.

a Cell viability (%) of BT474 and SKBR3 cells upon treatment with increasing concentrations of the TKI lapatinib, neratinib or tucatinib as monotherapy or in combination with 10 µg ml⁻¹ trastuzumab for 72 h. Data points represent the mean; error bars represent the standard error of the mean of 3 independent experiments. b Phosphorylation and total levels of HER2 and AKT upon 24 h of treatment with 10 µg ml⁻¹ trastuzumab plus TKI (10 nM lapatinib, 10 nM neratinib, 10 nM tucatinib) as assessed by Western Blot. c PAM50 signature scores in BT474 and SKBR3 cells untreated and treated with combinations of TKI and trastuzumab for 72 h. Each line represents a paired sample. Increases are represented in red and decreases in green. P-values (p) were determined by two-tailed paired t-tests. d Unsupervised hierarchical clustering using the PAM50 genes across BT474 and SKBR3 cells treated with combinations of TKI and trastuzumab for 72 h. The heatmaps show high (red) to low (green) expression of mRNAs in each sample. The molecular subtype call and treatment of each sample is shown. Source data are provided as a Source Data file.