Aberrant methylation of E-cadherin and H-cadherin genes in nonsmall cell lung cancer and its relation to clinicopathologic features.

Lung cancer is the leading cause of cancer deaths worldwide. The epigenetic inactivation of certain genes by aberrant promoter methylation plays an important role in the pathogenesis of lung cancer. In addition, DNA hypermethylation is an extremely promising cancer marker. Cadherins are cell adhesion molecules that modulate the epithelial phenotype and regulate tumor invasion. Although the aberrant methylation of E-cadherin (CDH1) or H-cadherin (CDH13) genes has been reported in lung cancer, to the authors' knowledge, the relation between the concurrent hypermethylation in E-cadherin and H-cadherin has not been explored to date. The authors investigated the methylation status of the promoter region of human E-cadherin and H-cadherin genes in resected samples of primary nonsmall cell lung cancer (NSCLC) using methylation-specific polymerase chain reaction (MSP) analysis and correlated the results with clinicopathologic characteristics. The methylation status of the promoter regions of the E-cadherin and H-cadherin genes was examined by using nested MSP in 88 primary lung cancers and paired adjacent normal tissues. Data were compared with clinicopathologic features. The frequency of methylation in neoplastic and corresponding nonneoplastic lung tissues was 30 of 88 tissue samples (34.1%) and 5 of 88 tissue samples (5.7%) for E-cadherin and 26 of 88 tissue samples (29.5%) and 7 of 88 tissue samples (8%) for H-cadherin, respectively. In addition, in 9 patients (10.2%), both genes were methylated. Although there was no significant difference in the overall survival of patients according to the methylation pattern of the E-cadherin gene alone or the H-cadherin gene alone, patients with NSCLC who had hypermethylation of both genes had a significantly longer overall survival. However, no correlation was observed between their methylation status and any other clinicopathologic factors. The current findings suggested that simultaneous methylation of the E-cadherin and H-cadherin genes occurs in a subset of NSCLCs and may be used as a prognostic marker for patients with NSCLC. However, further studies with large numbers of patients will be needed to confirm the findings.

Kim DS ，Kim MJ ，Lee JY ，Kim YZ ，Kim EJ ，Park JY ... -  《CANCER》

Aberrant methylation of H-cadherin (CDH13) promoter is associated with tumor progression in primary nonsmall cell lung carcinoma.

Abnormalities in the H-cadherin gene have been reported in several human malignancies, including nonsmall cell lung carcinoma (NSCLC). Aberrant methylation of the H-cadherin promoter also has been reported in NSCLC, but its clinical significance remains to be elucidated. The authors studied H-cadherin methylation in 305 patients with NSCLC to gain a further understanding of the clinicopathologic and prognostic significance of H-cadherin methylation in patients with NSCLC. The methylation status of the H-cadherin gene was investigated by using methylation-specific polymerase chain reaction analysis in paraffin blocks from 305 patients with NSCLC. Ki-67 expression was assessed by immunohistochemical staining. All statistical analyses were 2-sided with a 5% Type I error rate. H-cadherin methylation was observed in 130 of 305 tumor samples (43%). The prevalence of H-cadherin methylation was associated significantly with pathologic stage and was observed in 44% of patients with Stage I disease, in 23% of patients with Stage II disease, in 59% of patients with Stage III, and in 88% of patients with Stage IV disease (P = 0.001). H-cadherin methylation occurred with a 2.71 times greater prevalence (95% confidence interval [95% CI], 1.21-6.09; P = 0.01) T2 tumors than in T1 tumors and with a 3.78-fold greater prevalence (95% CI, 1.05-13.59; P = 0.04) in T3 tumors than in T1 tumors. However, lymph node metastasis was related inversely with H-cadherin methylation (odds ratio = 0.51; 95% CI, 0.28-0.95; P = 0.03), and H-cadherin methylation was not associated with the Ki-67 labeling index (P = 0.53) or with tumor size (P = 0.89). No relation was found between H-cadherin methylation and survival in patients with Stage I NSCLC (P = 0.51) or in patients with Stage II NSCLC (P = 0.46). The current findings suggested an association between H-cadherin methylation and tumor progression in NSCLC but had no prognostic significance in patients with early-stage NSCLC. In addition, H-cadherin methylation may be a valuable candidate molecular marker for the early detection of NSCLC.

Kim JS ，Han J ，Shim YM ，Park J ，Kim DH ... -  《CANCER》

Promoter hypermethylation of RASSF1A and RUNX3 genes as an independent prognostic prediction marker in surgically resected non-small cell lung cancers.

Yanagawa N ，Tamura G ，Oizumi H ，Kanauchi N ，Endoh M ，Sadahiro M ，Motoyama T ... -  《LUNG CANCER》

Aberrant promoter methylation of multiple genes in non-small cell lung cancers.

Zöchbauer-Müller S ，Fong KM ，Virmani AK ，Geradts J ，Gazdar AF ，Minna JD ... -  《CANCER RESEARCH》

Hypermethylation of E-cadherin gene is frequent and independent of p16INK4A methylation in non-small cell lung cancer: potential prognostic implication.

Shimamoto T ，Ohyashiki JH ，Hirano T ，Kato H ，Ohyashiki K ... -  《ONCOLOGY REPORTS》