Methylation of TIMP3 in esophageal squamous cell carcinoma

AimTo measure the frequency of DNA methylation of the tissue inhibitor of metalloproteinase 3 (TIMP3) promoter and relate this to any change of gene expression in esophageal squamous cell carcinoma in patients from a region of high incidence in China.MethodsCancer cell lines were treated with or without the demethylating reagent 5-aza-2'-deoxycytidine. Methylation of the TIMP3 promoter was assessed in three regions by melt curve analysis and its expression was assessed by real-time RT-PCR. Tumors and proximal resection margins were obtained from 64 patients with esophageal squamous cell carcinoma from a region of high incidence in China. Methylation was assessed by melt curve analysis and expression by immunohistochemistry.ResultsMethylation in one of the three promoter regions assessed correlated with gene silencing in esophageal cell lines. A degree of methylation of TIMP3 was found in only four esophageal squamous cell carcinomas, and partial loss of TIMP3 protein expression in just one.ConclusionMethylation and loss of expression of TIMP3 occurs infrequently in esophageal squamous cell carcinoma in a region of high incidence in China.Eric Smith, Neville J De Young, Zi-Qiang Tian, Maria Caruso, Andrew R Ruszkiewicz, Jun-Feng Liu, Glyn G Jamieson, Paul A Dre