Figure 3.

Treatment with NRG1 in SKBR3 (HER2+) breast cancer cells induces cell proliferation and impairs trastuzumab and pertuzumab efficacy. (A–H) Time-lapse analysis over time by Livecyte technology. SKBR3 cells were cultured in vitro and treated with/without NRG1 (10 ng/mL), alone or in combination with trastuzumab (10 µg/mL) or pertuzumab (10 µg/mL) and monitored up to 72 hours. Representative images at 72 hours post-treatment are provided in (A) scale bar 75 µm; Cell growth over time, normalized to cell number at 0 hours, is provided in (B); Cell growth and cell doubling time during the first day (0-24 hours), second day (24-48 hours), and third day (48-72 hours) are provided in (C–H) respectively. In all panels, numerical data are presented as mean (error bars show s.e.m.); statistical significance was determined using two-way ANOVA in (B) and one-way ANOVA in (C–H) followed by Tukey’s test; (*, &, #) p < 0.05, (**, ^^, °°, @@) p < 0.01, (***) p < 0.001, (****, ^^^^, °°°°) p < 0.0001.