Overexpression of long non-coding RNA UCA1 predicts a poor prognosis in patients with esophageal squamous cell carcinoma

Introduction: Long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in cancer biology, and the lncRNA UCA1 is upregulated in several cancers such as bladder cancer, breast cancer and colorectal cancer, however, the contributions of UCA1 to esophageal cancer remain largely unknown. Methods: Expression levels of lncRNA UCA1 in esophageal squamous cell carcinoma (ESCC) patients and esophageal cancer cell lines were evaluated by quantitative real-time PCR (qRT-PCR), and its association with overall survival of patients was analyzed by statistical analysis. Small interfering RNA was used to suppress UCA1 expression in esophageal cancer cell line. In vitro assays were conducted to further explore its underlying roles in tumor progression. Results: The relative level of UCA1 was significantly higher in ESCC tissues compared to the adjacent non-tumor tissues, and remarkably higher expression of UCA1 was found in esophageal cancer cell lines compared with the immortalized esophageal epithelial cell line NE1. The ESCC patients with higher UCA1 expression had an advanced clinical stage and a poorer prognosis than those with lower expression. In vitro assays, our data indicated that downregulation of UCA1 decrease cell proliferation, migration, and invasion ability. Conclusions: lncRNA UCA1 might be considered as a novel molecule involved in ESCC progression, which provides a potential prognostic biomarker and therapeutic target.