Allelic imbalance at the beta-catenin gene (CTNNB1 at 3p22-21.3) in various human tumor types

beta-catenin is a multifunctional protein: it plays a central role in the cell-cell adhesive junctions, and participates in transduction of the morphogenic Wingless/Wnt-signal. Upon detailed analysis of the human beta-catenin gene, an intragenic polymorphic microsatellite marker could be identified. This marker shows 62% heterozygosity and was used in a study of eleven different tumor types. A high level of beta-catenin allelic imbalance was observed for small cell lung carcinoma, squamous cell lung carcinoma and cervix carcinoma. Other microsatellite markers on 3p24-21 could demonstrate frequent but not invariable codeletion of flanking chromosomal loci. This intragenic polymorphic marker will allow selection of tumor types and tumor samples possibly bearing recessive mutations in the remaining allele of the beta-catenin gene.