Figure 8

Impact of the HER2 I767M mutation on glandular architecture of non-malignant breast epithelial cells. (A) Impact of transient expression of empty vector, wild-type HER2 (WT) and I767M mutant HER2 on growth and glandular architecture of MCF10A (top) and MCF12A (bottom) cells grown in three-dimensional basement membrane cultures (scale bar, 500 μm). The percentage of acinar structures ≥250 μm (MCF10A) and ≥200 μm (MCF12A) were quantified. **P < 0.01, ***P < 0.001, unpaired t-test. Error bars represent standard deviation of mean. (B) Impact of stable expression of empty vector, wild-type HER2 and I767M mutant HER2 on acinar size and lumina filling of MCF10A cells. Representative micrographs are shown (original magnification 40×). MCF10A cells expressing I767M mutant HER2 formed significantly larger acinar structures (left), which significantly more frequently displayed filled lumina (right) compared with MCF10A cells stably expressing empty vector or wild-type HER2. **P < 0.01, ****P < 0.0001, unpaired t-test. N.s., not significant. Error bars represent standard deviation of mean.