Overexpression of LncRNA-UCA1 Correlates with Lung Adenocarcinoma Progression and Poor Prognosis

Background: Long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been predicted to play a critical role in various biological processes including tumorigenesis. However, the clinical significance of UCA1 in lung adenocarcinoma (LUAD) is still not understood in detail. The aim of this study was to assess the clinical significance of the UCA1 expression levels in LUAD based on publicly available data and to evaluate its potential signaling pathways. Methods: The RNA-sequencing (RNA-seq) dataset and clinical information of all LUAD patients were downloaded from The Cancer Genome Atlas (TCGA). Kaplan-Meier plot and log-rank test were performed for survival analysis; Cox proportional hazards regression model were used to assess the relative factors. Furthermore, Starbase, Cbioportal, and Multi Experiment Matrix starbases were used to identify UCA1-related genes in LUAD. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of UCA1-related genes were performed using DAVID. Results: The expression level of UCA1 in LUAD tissues (n = 468) was significantly increased compared with the adjacent non-tumor lung tissues (n = 52) (p < 0.0001). In addition, UCA1 level was significantly correlated with TNM stage and lymph node metastasis. Survival analysis showed that UCA1 over-expression was significantly associated with poor overall survival (OS) (p = 0.0098) and poor recurrence-free survival (RFS) (p = 0.0298) in LUAD patients. Multivariate analysis confirmed that high expression of IncRNA-UCA1 was an independent prognostic factor of poor OS (HR = 1.353, 95% CI: 1.005 - 1.822, p = 0.046). Finally, KEGG analysis for UCA1-related genes indicated that UCA1 might be enriched with the microRNAs in cancer, pathways in cancer, endocytosis, focal adhesion, and proteoglycans in cancer. Conclusions: This study showed that UCA1 may be involved in lung carcinogenesis, which could act as a biomarker of prognosis and therapeutic target in LUAD patients.