Connexin 43, E-cadherin, beta-catenin and ZO-1 expression, and aberrant methylation of the connexin 43 gene in NSCLC.

BACKGROUND The relationships between connexin 43 (Cx43) expression and clinicopathological factors, epithelial markers, and CpG island methylation in non-small cell lung cancer (NSCLC) are controversial. The aim of this study was to investigate whether the Cx43 expression related with clinicopathological factors, epithelial markers and methylation status of the Cx43 gene. PATIENTS AND METHODS Correlations between the degree of immunohistochemical staining for Cx43 and epithelial markers (E-cadherin, beta-catenin, ZO-1), clinicopathological factors, and CpG island methylation status of the Cx43 gene, as assessed by pyrosequencing, were studied in 33 specimens of surgically treated NSCLC. RESULTS Weak Cx43 staining was correlated significantly with heavy smoking and weak E-cadherin or ZO-1 expression. The CpG island hypermethylation level was significantly associated with heavy smoking, poorly-differentiated tumour, and low expression of Cx43. CONCLUSIONS Both aberrant localization and epigenetic changes are associated with aberrant expression of connexin 43 in human NSCLC.