The Beta2-Adrenergic Receptor is a Potential Prognostic Biomarker for Human Hepatocellular Carcinoma After Curative Resection

Abstract

The beta2-adrenergic receptor (Beta2-AR) is overexpressed and highly associated with poor prognosis in many malignancies. Nevertheless, the role of Beta2-AR in hepatocellular carcinoma (HCC) has not been thoroughly elucidated. The aim of this study is to investigate the expression of Beta2-AR and its clinicopathological/prognostic value in HCC patients after curative resection. Semiquantitative reverse transcription PCR (RT-PCR) and real-time quantitative PCR (qPCR) were used to measure Beta2-AR RNA expression in 60 pairs of HCC tumors and matched nontumorous tissues. Beta2-AR expression was detected in HCC cell lines by Western blot analysis. Furthermore, we investigated Beta2-AR expression in correlation with the clinicopathological features and analyzed the potential prognostic significance of Beta2-AR in 192 HCC patients by immunohistochemistry (IHC). Upregulation of Beta2-AR mRNA was significantly higher in HCC tumor tissues than in their paired nontumorous liver specimens. The expression of Beta2-AR protein was detected in five HCC cell lines. Positive Beta2-AR protein expression was significantly associated with a high α-fetoprotein (AFP) level (P = 0.001), large tumor size (P < 0.001), tumor encapsulation (P = 0.002), vascular invasion (P = 0.004), microsatellite formation (P = 0.002), and poor differentiation (P < 0.001). In univariate and multivariate analyses, Beta2-AR was an excellent predictive factor for both recurrence-free survival and overall survival (OS). Beta2-AR expression status was associated with poor prognosis independent of AFP, tumor-node-metastasis stage and Edmondson stage. The Beta2-AR is a potential prognostic biomarker for survival and tumor recurrence in HCC patients after curative resection.