The expression and clinical significance of syncytin-1 in serum exosomes of hepatocellular carcinoma patients.

This study aimed to investigate the expression and clinical significance of syncytin-1 in the serum exosomes of hepatocellular carcinoma (HCC) patients. Serum samples were collected from 61 patients with newly diagnosed HCC and 61 healthy individuals. Exosomes were extracted from serum samples and identified using transmission electron microscopy and Western blot. The relative expression levels of syncytin-1 in exosomes were determined by real-time quantitative PCR. The protein expression levels of alpha-fetoprotein and syncytin-1 in HCC patients were detected using enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed to evaluate the sensitivity and specificity of serum exosomal syncytin-1 in diagnosing HCC. The relationships between syncytin-1 expression and clinical pathological features were analyzed using receiver operating characteristic curve analysis. The results showed that the expression level of syncytin-1 in the serum of patients with newly diagnosed HCC was significantly higher than that in the normal control group (P < 0.0001). Using pathological diagnosis as the gold standard, the sensitivity and specificity of syncytin-1 for the auxiliary diagnosis of HCC were 91.3% and 75.5%, respectively, which were significantly higher than those of alpha-fetoprotein (P < 0.0001). The relative expression level of serum exosomal syncytin-1 was significantly associated with lymph node metastasis, degree of differentiation, and CNLC staging of HCC patients (P < 0.05). In conclusion, syncytin-1 in serum exosomes has high sensitivity and specificity for diagnosing HCC and can serve as a novel tumor marker for early screening, detection, and staging of HCC.