Long Noncoding RNA HNF1A-AS1 Regulates Proliferation and Migration in Esophageal Adenocarcinoma  Cells
Objectives: Long non-coding RNAs (lncRNAs) have been shown to play important roles in the development and progression of cancer. However, functional lncRNAs and their downstream mechanisms are largely unknown in the molecular pathogenesis of esophageal adenocarcinoma (EAC) and its progression. Design: lncRNAs that are abnormally upregulated in EACs were identified by RNA-seq analysis, followed by quantitative RT-PCR (qRTPCR) validation using tissues from 31 EAC patients. Cell biological assays in combination with siRNA-mediated knockdown were performed in order to probe the functional relevance of these lncRNAs. Results: We discovered that a lncRNA, HNF1A-AS1, is markedly upregulated in human primary EACs relative to their corresponding normal esophageal tissues (mean fold change 7.2, p<0.01). We further discovered that HNF1A-AS1 knockdown significantly inhibited cell proliferation and anchorage independent growth, suppressed S-phase entry, and inhibited cell migration and invasion in multiple in vitro EAC models (p<0.05). A gene ontological analysis revealed that HNF1A-AS1 knockdown preferentially affected genes that are linked to assembly of chromatin and the nucleosome, a mechanism essential to cell cycle progression. The well-known cancer-related lncRNA, H19, was the gene most markedly inhibited by HNF1A-AS1 knockdown. Consistent to this finding, there was a significant positive correlation between HNF1A-AS1 and H19 expression in primary EACs (p<0.01). Overall design: In order to identify novel oncogenic lncRNAs in esophageal adenocarcinogenesis, we carried out RNA-seq of a matched NE-BE-EAC tissue pair