FIG. 5.

Signaling pathways required for increased synthesis of HBEGF during hypoxia. HTR-8/SVneo (A) or SW.71 (B) cells were labeled with an antibody against HBEGF after culturing at 20% (gray bars) or 2% O₂ (black bars) in the presence of kinase inhibitors or their inactive structural analogues (inactive analogues), as indicated by their target pathway. The HBEGF-specific antagonist, CRM197, was also used to block HBEGF signaling. All possible combinations of inhibitors or their inactive structural analogues were assessed, but only the most relevant combinations are shown here. Image analysis was used to quantify the relative stain intensity, which is shown in arbitrary units on the horizontal axis. Values represent the average ± SEM of at least three experiments; *P < 0.05.