Clinical Outcomes of Downregulation of E-cadherin Gene Expression in Non-small Cell Lung Cancer

Objective: To investigate the promoter methylation status of the E-cadherin gene in non-small cell lung cancer(NSCLC) and its association with clinical pathological parameters, and to explore the relationship betweendownregulation of E-cadherin gene expression and the methylation status of its promoter region.
Methods:Nested methylation-specific PCR was performed to examine CpG methylation within the 5’ CpG island of theE-cadherin gene in lung cancer and para-cancerous tissue from 37 patients with primary non-small cell lungcancer. Quantitative real-time PCR was performed to measure the level of E-cadherin mRNA.
Results: Ofthirty-seven cases, 12 (32.4%) samples showed aberrant CpG methylation in tumor tissues compared with thecorresponding normal tissues. In addition, a reduction in E-cadherin mRNA levels was observed in 11 of the12 (91.7%) tumor tissues carrying a methylated E-cadherin gene. However, only 10 (43.5%) cases displayedreduced mRNA levels in tumor tissues from the remaining 23 cases (excluding 2 samples from which mRNA wasunavailable) without methylation events. Downregulation of E-cadherin gene expression significantly correlatedwith the promoter methylation status of this gene.
Conclusion: These results provide strong evidence that themethylation status of E-cadherin gene contributes to a reduction in the expression of E-cadherin mRNA, andmay play a role in the development and progression of NSCLC.