The JNK interacting protein JIP-1 and insulin like growth factor II genes are co-expressed in human embryonic tumours.

JNK interacting protein 1 (JIP-1) is a pivotal scaffolding protein in the JNK signalling pathway. It is believed to play a role in the mediation of mitogenic messages from the plasma membrane to the cell interior. Recent evidence suggests that the JIP-1 gene is co-regulated with the insulin like growth factor II (IGF II) gene, thereby contributing to the growth-promoting effects of this potent growth factor. In this study, fourteen embryonic tumours were examined for the expression of JIP-1 and IGF II. It was found that, irrespective of histological type and expression level, the two genes showed a high degree of co-variation in the sense that high IGF II expression was followed by high expression of JIP-1. This finding further supports the notion that JIP-1 and IGF II act in concert to enhance cell proliferation.