Loss of insulin binding and insulin receptor mRNA in a transformed human fetal fibroblast cell line

Insulin binding and insulin receptor gene expression have been assessed in cultured fetal (WI38) and SV40 transformed fetal (WI38/VA13) human fibroblasts to determine whether transformation influences the expression of insulin receptors. The transformed cell line had virtually no insulin binding and extremely low levels of insulin receptor mRNA. No apparent gene deletion or rearrangement was detected and therefore the marked decrease in insulin receptor gene expression seen in WI38/VA13 cells is an important example of negative regulation of insulin receptor gene expression. This cell line could serve as a model for studies of the mechanism for negative regulation of insulin receptor gene expression. Overexpression of the insulin receptor gene in these cells may reveal insights into the role of the insulin receptor in tumor biology.