Correlation of Long Noncoding RNA SEMA6A-AS1 Expression with Clinical Outcome in HBV-Related Hepatocellular Carcinoma

Purpose: Hepatocellular carcinoma (HCC) is the seventh most commonly diagnosed cancer and the fourth-leading cause of cancer-related death worldwide. Chronic hepatitis B virus (HBV) is the leading cause of HCC in China. Emerging evidence suggests that long noncoding (lnc)-RNAs are deregulated and are involved in the development of HCC. Our previous study found that HBV X protein can promote HCC by altering lncRNA expression profiles. The purpose of this study was to investigate the expression of the lncRNA semaphorin 6A–antisense RNA 1 (SEMA6A-AS1) and its prognostic value in HBV-related HCC. Methods: Samples of HCC tissues and adjacent nontumor tissues were collected from patients who were pathologically diagnosed with HBV-related HCC after hepatectomy. Eligible patients had not received preoperative radiotherapy, chemotherapy, or embolotherapy. Real-time quantitative reverse-transcription polymerase chain reaction was performed to evaluate the expression levels of SEMA6A-AS1 in all tissue specimens. The correlations between SEMA6A-AS1 expression and clinicopathologic characteristics were analyzed using the χ² test and the Fisher exact test. Overall survival curves constructed by the Kaplan–Meier method and univariate analysis made by Cox proportional hazards modeling were used for determining the prognostic significance of SEMA6A-AS1. Findings: Specimens were collected from 47 patients (45 men, 2 women; mean age, 48.4 [10.7] years). SEMA6A-AS1 expression was significantly downregulated in HBV-related HCC tissues compared with that in adjacent noncancerous hepatic tissues (P < 0.01). Low levels of SEMA6A-AS1 were correlated with high α-fetoprotein level (P = 0.002), high Edmondson-Steiner tumor grade (P = 0.047), high tumor node metastasis stage (P = 0.01), capsular invasion (P = 0.005), and poor clinical response (P = 0.002). Additionally, both Kaplan–Meier estimator and univariate Cox regression analysis revealed that low SEMA6A-AS1 expression was significantly associated with poor overall survival (P < 0.05). Implications: The results show that low expression of SEMA6A-AS1 was associated with a poor prognosis in patients with HBV-related HCC. It is necessary to determine the function and mechanism of SEMA6A-AS1 in HCC in order to identify it as a prognostic biomarker and therapeutic target.