Effect of the pan-JNK inhibitor SP600125 on EREG expression. (a) EREG transcript level was measured by qPCR in U87 cells after a 6-h incubation with or without 10 μg/ml tunicamycin and/or 25 μM SP600125. Results were expressed as fold-change relative to U87Ctrl cells in the absence of Tun and SP600125 and were normalized using the HPRT1 reference gene. Results are mean values ± SD. (b) Kinetics of JNK phosphorylation in the presence of 10 μg/ml tunicamycin. U87 cells were treated with or without Tun as above. Cell extracts were used for immunoblotting to measure activation of JNK using an anti-phospho-JNK (p-JNK) antibody and antibodies directed against the total (JNK) protein. α-tubulin was used as the reference.