TY - JOUR T1 - Loss of Heterozygosity and Nonsense Mutation in <em>Apc</em> in Azoxymethane-induced Colonic Tumours in <em>Min</em> Mice JF - Anticancer Research JO - Anticancer Res SP - 2595 LP - 2600 VL - 24 IS - 5A AU - LINDA MØLLERSEN AU - JAN ERIK PAULSEN AU - JAN ALEXANDER Y1 - 2004/09/01 UR - http://ar.iiarjournals.org/content/24/5A/2595.abstract N2 - C57BL/6J Min/+ mice, which carry a nonsense mutation in Apc, were injected twice neonatally with 5 mg azoxymethane (AOM) /kg body weight. AOM treatment in comparison with untreated Min mice increased the incidence and number of colonic tumours from 6/14 to 22/24 (incidence) and 0.64±0.9 to 4.0±3.5 tumours per mice, respectively. Colonic tumours were analysed for loss of heterozygosity (LOH) in Apc, and 32 of the samples showed LOH whereas 14 did not. In untreated Min mice, all 8 tumours had LOH in Apc. All tumour samples from the AOM-treated Min mice were analysed for nonsense mutations between codons 686 and 1217 in the Apc gene, and one sample had a G→ A transition mutation in codon 1047. No β-catenin mutations in the region coding for phosphorylation sites important for degradation were found. In conclusion, the main mechanism for colonic tumour induction in AOM-induced Min mice is LOH in Apc, but Apc nonsense mutations may also occur. Copyright© 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved ER -