Long Non-Coding RNA NRAD1 and LINC00152 are Highly Expressed and Associated with Prognosis in Patients with Hepatocellular Carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) is prevalent throughout the world. The aim of this study is to explore new long non-coding RNAs (lncRNAs) associated with hepatocellular carcinoma and detect their expression levels in hepatocellular carcinoma cell lines and tissues. These results will provide new clues on further function and biomarker studies of HCC-related lncRNAs. PATIENTS AND METHODS: All patients were diagnosed as HCC between 30th, March, 2015 and 30th, July, 2018. LncRNA human gene expression microarray was applied to the profiling of lncRNAs in four cancerous tissues and the paired paracancerous tissues. RESULTS: We retrospectively reviewed 63 patients with primary HCC who underwent a curative liver resection at the Department of Hepatology, Qingdao Sixth People’s Hospital. The expression level of lncRNA NRAD1 and LINC00152 was detected by real-time PCR. Prognostic factors were evaluated using Kaplan–Meier curves and Cox proportional hazards models. By microarray profiling of lncRNAs, 256 lncRNAs were found to be differentially expressed, including 162 upregulated and 94 downregulated (P<0.05, fold change>2). Two candidate lncRNAs were determined as the targets in this study, which were NRAD1 (upregulated by 6.35 fold), LINC00152 (upregulated by 4.53 fold). NRAD1 and LINC00152 were downregulated in the normal liver cell lines Chang liver, HL7702, THLE-2, THLE-3, FL62891 and AML12, which were significantly lower than HCC cell lines SMMC-7721, Hep3B, HuH7, MHCC-97H, HCC-LM and SK-Hep-1 (P<0.05). Overexpression of lncRNA NRAD1 and LINC00152 was associated with decreasing OS rates, respectively (P=0.0263 and P=0.0285). Meanwhile, overexpression of NRAD1 and LINC00152 was associated with decreasing PFS rates, respectively (P=0.0174 and P=0.0041). After adjusting for competing risk factors, we identified that microvascular invasion (P=0.014), tumor size (P=0.026), lncRNA NRAD1 (P=0.001) and LINC00152P9 (P=0.036) expression levels were independent prognostic factors associated with prognosis of patients with HCC. CONCLUSION: We found lncRNA NRAD1 and LINC00152 expressed significantly higher in HCC tissues compared with non-tumorous tissues. Overexpression of lncRNA NRAD1 and LINC00152 were independent risk factors associated with the prognosis of patients with HCC.