Regulation of insulin-like growth factor-II gene expression in rat INS-1 cells

Objective To study the effects of different glucose concentrations on IGF Ⅱ gene expression and cell proliferation in INS 1 cells and to compare the effects of glucose on IGF Ⅱ and insulin gene expressions. Methods The IGF Ⅱ and insulin gene expressions were determined by Northern blot. The cell proliferation was assessed by 3H thymidine incorporation assay. Results IGF Ⅱ gene mRNA was expressed in INS 1 cell line. IGF Ⅱ mRNA was increased more than three folds at glucose concentration of 10～20 mmol/L. Phorbol 12 myristate 13 acetate (PMA) had no effect on IGF Ⅱ gene expression and proliferation in INS 1 cells, and Forskolin suppressed the stimulatory effects of glucose on the IGF Ⅱ mRNA expression. Conclusion In higher glucose concentration IGF Ⅱ mRNA is highly expressed, while insulin mRNA is highly expressed in lower glucose concentration.