Fig. 1

Characterization of resistant cell lines. Cell viability of control (CTR), Trastuzumab (T), Pertuzumab (P), and T + P cell lines treated with 10 and 100 μg/ml trastuzumab, pertuzumab and trastuzumab+pertuzumab for 5 days was evaluated by MTT assay (a). Western Blot (WB) analysis of phosphorylated and total HER2, HER3, EGFR, AKT and ERKs was performed on total cell lysates from untreated/treated parental cell lines for 7 days (b, leftmost panel). The basal levels of phosphorylated and total HER2, HER3, EGFR, AKT and ERKs were evaluated by WB in CTR, T, P, and T + P resistant cell lines (b, rightmost panel). HER2 total and phosphorylated levels evaluation by WB was repeated in CTR, T, P, and T + P cell lines following resistant cell lines establishment (c). The anti-HSP70 antibody was used to validate equivalent amount of loaded proteins in each lane. Proliferation curves (d) and Invasion assay (e, upper panel) of CTR, T, P, and T + P cell lines. Representative images of invaded cells are reported for each cell line (e, lower panel)