Figure 2

IL8 or CXCR1 blockade reduces HER2/HER3-evoked invasion of mammary cells. (A) Quantitative real-time PCR of IL8. The bar graph shows the percentages of IL8 expression in MCF10A cells expressing empty vector, HER2, HER3 or HER2/HER3, as well as in the HER2/HER3-positive breast cancer cell line BT474. Results represent means ± standard error of the mean (SEM) (n = 3, *P < 0.018; NS, not significant). (B) Percentage of invasive structures upon stimulation of MCF10A cells with IL8. Results represent means ± SEM (n = 3, *P < 0.05). (C) Representative phase-contrast pictures of MCF10A-HER2/HER3 cells grown in three-dimensional cultures for 15 days in the presence of heregulin and the indicated neutralizing antibodies. The bar graph shows the percentages of invasive structures. Results represent means ± SEM (n = 3, *P < 0.0004; NS, not significant). (D) Representative phase-contrast pictures of BT474 cells grown in three-dimensional cultures for 15 days in the presence of heregulin and neutralizing antibodies. The bar graph shows the percentages of aberrant structures. Results represent means ± SEM (n = 3; *P < 0.05; NS, not significant). CTRL, control.