Overexpression of hERG1 in resected esophageal squamous cell carcinomas: A marker for poor prognosis

Background and Objectives: The aim of this study was to evaluate the expression and prognostic roles of human ether A go-go related gene (hERG 1) potassium channels in resected esophageal squamous cell carcinoma. Methods: Expression of hERG1 protein and mRNA was detected by immunohistochemistry and reverse transcription PCR in resected esophageal squamous cell carcinomas (ESCCs) and non-cancerous matched tissues, and the correlation was examined between expression of hERG1 protein and clinicopathological factors and prognosis of ESCC patients. Results: Frequency of positive expression of hERG1 protein was 77.9% (53/68), mRNA was 81.8% (9/11). hERG1 protein and mRNA were negatively expressed in all non-cancerous matched tissues. There was no significant correlation between hERG1 protein expression and lymph node metastases, depth of penetration, stage, and other clinicopathological factors. Completeness was 92.5% for hERG1-positive group and 92.0% for hERG1-negative group. ESCC patients with positive expression of hERG1 protein had a significantly shorter postoperative survival time than those with negative expression (median, 30 vs. 56 months). Survival rates at each time-point for hERG1-positive group were lower than that for hERG1-negative group, and hERG1 was identified as ail independent prognostic factor of long-term survival by multivariate analysis. Conclusion: In ESCC, hERG1 was aberrantly expressed and correlated with poor prognosis after surgery.