APC protein levels in HCT-116 cells treated with MNNG. HCT-116 cells were treated with different concentrations of MNNG (0–100 μM) for 15 h, and then APC protein was analyzed as described in Materials and Methods. Panel A shows a representative autoradiogram of the APC protein.Panel B is a quantitative analysis of the APC protein level in MNNG-treated HCT-116 cells. The data are mean ± SE of three different experiments. * = significantly different than untreated cells.