Figure 3 of
Hollborn, Mol Vis 2005;
Figure 3. EGF receptor tyrosine kinase and ERK1/2 mediate the mitogenic effect of HB-EGF
A: The dose-response relationship of HB-EGF on the DNA synthesis rate is shown. B: The mitogenic effect of HB-EGF was inhibited in the presence of a neutralizing anti-HB-EGF antibody (5 μg/ml). C: The effect of HB-EGF (50 ng/ml) was abolished in the presence of blockers of the EGF receptor tyrosine kinase. The following substances were tested: dimethylsulfoxide (DMSO; 0.1%), ethanol (1%), AG1478 (300 nM), PD158780 (500 nM), AG1296 (10 μM). D: HB-EGF (50 ng/ml) evoked cell proliferation via activation of ERK-1 and ERK-2. The following substances were tested: MEK1 and MEK2 inhibitor UO126 (4 μM), inhibitor of p38 MAPK activation, SB203580 (10 μM), and the PI3K inhibitor, LY294002 (5 μM). The test substances were applied for 24 h, and the DNA synthesis rate was measured by estimation of BrdU incorporation. Data are expressed in percent of the untreated control. Each bar represents the mean of 3 to 6 independent experiments carried out in triplicate; error bars represent SEM. Asterisks indicate a statistically significant difference (* for p<0.05, *** for p<0.001) compared with untreated control. Plus symbols indicate a statistically significant effects of the blockers (+ for p<0.05, ++ for p<0.01, +++ for p<0.001).