Hypoxia-regulated MicroRNAs in Gastroesophageal Cancer

Abstract

Background/aim: The present study aimed to identify hypoxia-regulated microRNAs (HRMs) in vitro and investigate the clinical role of candidate HRMs in patients with gastroesophageal cancer (GEC). Materials and Methods: microRNA expression changes induced by hypoxia in human GEC cell lines were measured with microarrays and validated by quantitative real-time polymerase chain reaction. Candidate HRMs were measured in pre-therapeutic tumor samples from 195 patients with GEC. Results: Expression of miR-210 was shown to be significantly induced in esophageal squamous cell carcinoma (9.26-fold, p<0.001) and adenocarcinoma cell lines (4.95-fold, p<0.001) and miR-27a-star was significantly up-regulated in adenocarcinoma cell lines (4.79-fold, p=0.04). A weak but significant correlation between miR-210 expression and a 15-gene hypoxia signature was observed (Pearson r correlation: r=0.38, p<0.001). No significant associations of HRMs and clinical outcome in patients with GEC were identified. Conclusion: This study supports the involvement of hypoxia on miRNAs in vitro and confirms the role of miR-210 as being a universal HRM.