AIMS AND BACKGROUND: Studies reporting activated Wnt signaling in all stages of chronic myeloid leukemia (CML) have demonstrated that deregulation of the pathway plays a role in the pathogenesis of this disease. Several reports have suggested mechanisms for the deregulated Wnt signaling and beta-catenin stabilization observed in CML. One possible mechanism for beta-catenin stabilization could be the acquisition of mutations at its N-terminal domain, especially in the third exon where it is marked via phosphorylation for degradation. We sought to determine whether mutations in the third exon of the beta-catenin gene are responsible for the observed Wnt activation in CML. MATERIAL AND METHODS: We screened bone marrow specimens from 33 patients with CML in the chronic phase and also examined the K562 cell line for beta-catenin mutations. RESULTS: None of the patients nor the K562 cell line were found to carry mutations. CONCLUSION: Beta-catenin amino-terminal mutations are not observed or very rare and therefore are not the underlying mechanism of activated Wnt signaling in CML.
AIMS AND BACKGROUND: Studies reporting activated Wnt signaling in all stages of chronic myeloid leukemia (CML) have demonstrated that deregulation of the pathway plays a role in the pathogenesis of this disease. Several reports have suggested mechanisms for the deregulated Wnt signaling and beta-catenin stabilization observed in CML. One possible mechanism for beta-catenin stabilization could be the acquisition of mutations at its N-terminal domain, especially in the third exon where it is marked via phosphorylation for degradation. We sought to determine whether mutations in the third exon of the beta-catenin gene are responsible for the observed Wnt activation in CML. MATERIAL AND METHODS: We screened bone marrow specimens from 33 patients with CML in the chronic phase and also examined the K562 cell line for beta-catenin mutations. RESULTS: None of the patients nor the K562 cell line were found to carry mutations. CONCLUSION: Beta-catenin amino-terminal mutations are not observed or very rare and therefore are not the underlying mechanism of activated Wnt signaling in CML.