Frontiers in Bioscience-Elite (FBE) is published by IMR Press from Volume 13 Issue 2 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
The molecular mechanisms and candidate genes involved in metastasis to the brain need elucidation. In the present study brain metastases were analyzed regarding changes of E-cadherin (CDH1) and beta-catenin (CTNNB1). Loss of heterozygosity (LOH) of the CDH1 gene was detected in 42.2% of samples. The highest frequency of LOHs was observed in metastases from primary sites of lung adenocarcinoma and small cell lung cancer. Metastases from breast and colon demonstrated changes in 55.6% and 50% of cases. Downregulation of E-cadherin protein was observed in 83% of samples. Only 21.1% of samples with E-cadherin LOH had beta-catenin located in the nucleus. Image analysis showed that the quantities of E-cadherin and beta-catenin were significantly positively correlated (P = 0.008). Changes of E-cadherin were frequent in brain metastases that we investigated. Lack of mutations of beta-catenin, the fact that it was not frequently found in the nucleus and the positive correlation between the two proteins may suggest that the break-up of adherens junctions, and not the activation of wnt signaling, is responsible for metastasis formation.