Sperm-Associated Antigen 5 Expression Is Increased in Hepatocellular Carcinoma and Indicates Poor Prognosis

BACKGROUND Sperm-associated antigen 5 (SPAG5), a gene that encodes a mitotic spindle-associated protein, is closely related to tumor development and is involved in cell migration and proliferation. The objective of this research was to explore the clinical significance of SPAG5 expression in hepatocellular carcinoma (HCC) and the relationship between SPAG5 expression and HCC prognosis. MATERIAL AND METHODS Twenty pairs of fresh-frozen HCC samples and samples from 95 HCC patients in a tissue microarray were subjected to quantitative real-time reverse-transcription (qRT)-PCR and immunohistochemistry (IHC), respectively, to investigate the relationship between the expression of SPAG5 and the clinicopathological features of HCC patients. RESULTS PCR data showed that the messenger RNA (mRNA) expression level of SPAG5 in HCC tissue specimens was higher than that in adjacent non-tumor tissue specimens (p<0.05). IHC analyses demonstrated that SPAG5 expression was significantly correlated with tumor grade (p=0.003), tumor number (p=0.009), vascular invasion (p=0.001), and TNM stage (p=0.001). Survival analysis and Kaplan-Meier curves showed that SPAG5 expression is an independent prognostic indicator for disease-free survival (p=0.017) and overall survival (p=0.016) in HCC patients. CONCLUSIONS Our results indicate that SPAG5 expression may be considered as an oncogenic biomarker and a novel predictor for HCC prognosis.