Inhibition of ERK1/2 or JNK signaling abolishes the proliferative and anti-apoptotic effects of insulin/IGF-1 <i>in vitro</i>.

<p>MC38 cells were cultured with insulin and IGF-1 alone or both together for 72 hours. ERK1/2 inhibitor PD98059 (B), JNK inhibitor SP600125 (C) or their vehicle DMSO added to the cultures when MC38 cells were treated with both insulin and IGF-1. (A) Cells were collected for proliferation analysis with CCK-8 assay at 24, 48 and 72 hour. **P<0.01; ***P<0.001 between the indicated two groups, n = 3 per group. (B and C) Western blotting analysis for p-ERK1/2, ERK1/2, p-JNK, JNK, Cyclin D1, Bcl2, Bax and Caspase3 protein expression in the treated MC38 cells. GAPDH served as a loading control. The blots shown are representative of three separate experiments.