Blum, Carmen A.;Xu, Meirong;Orner, Gayle A.;Diaz, G.Daria;Li, Qingjie;Bailey, George S.;Dashwood, Roderick H.
5
The carcinogens 2-arnioo-3-methylimidazo[4,5-f]quinoline (IQ) and 1,2-dimethylhydrazine (DMH) induce colon tumors in the Fisher 344 rat that contain mutations in Ctnnb1, the gene for b-catenin, but the pattern of mutation differs from that found in human colon cancers. in both species, mutations affect the glycogen synthase kinase 3$\beta$ (GSK-3$\beta$) consensus region of $\beta$-catenin, but whereas they directly substitute critical Ser/Thr phosphorylation sites in human colon cancers, the majority of mutations cluster around Ser$^{33}$ in the rat tumors.(omitted)