Genetic changes of CDH1, APC, and CTNNB1 found in human brain tumors.

This paper focuses on changes in E-cadherin (CDH1), adenomatous polyposis coli (APC), and beta-catenin (CTNNB1) in 50 tumors of the central nervous system. All gene products are components of adherens junctions, but are also involved in wnt signaling. The results of our analysis showed LOH of CDH1 gene in 31% of meningiomas examined (significant correlation; p=0.002). LOH was noted in a single case of germinoma, while other tumor types did not demonstrate any change in CDH1. Fourteen samples (29.2%) with changes in APC gene were observed. The changes were seen in 33.3% of glioblastomas and in 27% of meningiomas; LOH occurred in five informative astocytomas (20%) and in six informative neurinomas (17%). One oligoastrocytoma showed LOH at exon 11, and one medulloblastoma had allelic imbalance at both exons. Five samples (10%) showed heteroduplexes in exon 3 of beta-catenin. Potential mutations were confined to two meningiomas, one astrocytoma, one glioblastoma, and one germinoma. Our results suggest that genetic changes in wnt components are involved in brain tumor genesis. Changes in E-cadherin are involved in meningiomas, while changes in APC gene occur in different tumor types, with glioblastomas showing the highest percentage.