Synergism between Hedgehog-GLI and EGFR Signaling in Hedgehog-Responsive Human Medulloblastoma Cells Induces Downregulation of Canonical Hedgehog-Target Genes and Stabilized Expression of GLI1
Figure 7
Hedgehog/EGF crosstalk analyzed on the signaling level by RPPA.
Samples were obtained at 14 time points after inducing EGFR signaling in Shh-N primed Daoy cells or control Daoy cells by EGF. Daoy cells were either treated with control medium (purple), Shh-N conditioned medium (blue), EGF (red) or a combinatorial treatment with Shh-N medium and EGF (green) treated for 24 h. Data for selected phosphoproteins are shown for short time signaling (A: 0–6 h) and long term signaling (B: 6–24 h). Certain kinases, e.g. MEK and ERK1/2, clearly depend on fast signals mediated by EGFR, most proteins assessed by RPPA show no significant changes on the phosphoprotein level as shown here for p70S6K and GSK3 signaling. Table 2 summarizes phosphoproteins probed by RPPA.