Increased expression of annexin A1 predicts poor prognosis in human hepatocellular carcinoma and enhances cell malignant phenotype

Annexin A1 (ANXA1) belongs to the annexin superfamily of proteins, which contribute to the pathological consequence and sequelae of most serious human diseases. Recent studies have reported diverse roles of ANXA1 in various human cancers; however, its involvement in human hepatocellular carcinoma (HCC) still remains controversial. To investigate the expression pattern of ANXA1 in HCC tissues and evaluate its associations with tumor progression and patients' prognosis, immunohistochemistry was performed using 160 pairs of formalin-fixed and paraffin-embedded cancerous and adjacent non-cancerous tissues from patients with HCC. Then, the associations between ANXA1 expression, clinicopathological characteristics, and prognosis of HCC patients were statistically evaluated. In vitro migration and invasion assays of siRNA-targeted ANXA1-transfected cells were further performed. As a result, the expression levels of ANXA1 protein in HCC tissues were significantly higher than those in adjacent non-cancerous tissues (P < 0.001). High ANXA1 expression was closely correlated with advanced TNM stage (P = 0.001) and high Edmondson grade (P = 0.02). Then, univariate and multivariate analyses showed that the status of ANXA1 expression was an independent predictor for overall survival of HCC patients. Furthermore, knockdown of ANXA1 by transfection of siRNA-ANXA1 could suppress the migration and invasion abilities of HCC cells in vitro. Collectively, these findings offer the convincing evidence that ANXA1 may play an important role in HCC progression and can be used as a molecular marker to predict prognosis and a potential target for therapeutic intervention of HCC.