Insulin-induced keratinocyte migration is insulin receptor-dependent and EGFR-independent. HaCaT Cells were plated in the cloning ring migration assay as described. (A) Cells were pre-treated with 1.5 μg of neutralizing insulin receptor Ab 29B4 for 1 h, then treated with 10-7 M or 10-6 M insulin for 24 h. Neutralizing insulin receptor Ab inhibited 10-7 M but not 10-6 M insulin-induced cell migration, showing that the effect of 10-7 M insulin on keratinocytes is mediated primarily through the insulin receptor. (B) Cells were pre-treated with either 50 nM IGF-1 receptor inhibitor picropodophyllin, 1.5 μg neutralizing insulin receptor Ab 29B4, or insulin receptor Ab 29B4 plus picropodophyllin for 1 h, then treated with 10-7 M or 10-6 M insulin or left untreated for 24 h. The effects of a higher dose of insulin but not a lower dose are mediated by both the insulin receptor and the IGF-1 receptor. (C) Cells were pre-treated with 3 μM of the EGF-R inhibitor AG1478 for 1 h, followed by treatment with 10-7 M insulin; migration distance was measured at 24 and 48 h after treatment. Insulin-induced migration was not prevented by the EGF-R inhibitor. Each treatment group was performed in triplicate. Data is shown as the mean value +/- SD. Statistics are shown as comparisons between the treatment and control, unless otherwise indicated. *P < 0.05, **P < 0.01. ***P < 0.001.
Liu et al. BMC Cell Biology 2009 10:1 doi:10.1186/1471-2121-10-1