The co-expression of JNK interacting protein JIP-1 and insulin like growth factor II can be dissocoiated in Wilms tumor cell lines but not in primary wilms tumours

JNK interacting Protein 1 (JIP-1) is an important scaffolding protein in the JNK signalling pathway. It is also believed to play a role in the mediation of mitogenic messages from the plasma membrane to the cell interior. Previous studies suggest that the JIP-gene is co-regulated with the insulin like growth factor II (IGF II) gene., thereby contributing to the growth stimulatory effects of this potent growth factor. The striking co-expression of these two genes was found in murine fetuses as well as in primary human embryonic tumours. When ten primary Wilms Tumours were examined, the two genes showed a high degree of co-variation in the sense that high expression of IGF II was followed by high expression of JIP-1 and vice versa. However when the human Wilms Tumour cell line WCCS-1 was examined, a very modest intrinsic expression of IGF II was accompanied by a high expression of JIP-1. When exogenous IGF I was added, (which has previously been shown to induce apoptosis in this cell line), the JIP-expression was increased. This data suggests that JIP-1 has a more complex role in the regulation of proliferation as well as programmed cell death