Figure 5

Impact of ERBB2 expression on the activity of ERBB signaling pathway in mice. (A) Scheme of the minimal molecular network defining the regulations between KRAS, EGFR, and ERBB2. (B) Relative RNA expression levels of mouse Egfr, Erbb2 and Kras in the absence (blue bars) or in the presence of acute cerulein treatment (red bars), as determined experimentally in mice (left) and predicted by mathematical modeling (right). Expression data are mean +/− SD, n ≥ 3. *, p < 0.05 and *** p < 0.001. (C) Modeling ERBB signaling activity (red curves) as a function of Egfr or Erbb2 mRNA in the absence (left panels) or in the presence of acute cerulein treatment (right panels). Each black dot represents a cell in a heterogeneous cell population where 50% of uniform random variations are considered around the basal value of each parameter (see Supplementary Information for details). Vertical blue lines correspond to the measured mean expression levels of Egfr and Erbb2 with or without inflammation as shown in (B). These expression levels are relative to Erbb2 expression in the absence of treatment.