Expression and significance of annexin A2 in patients with gastric adenocarcinoma and the association with E-cadherin.

Annexin A2 is a calcium-dependent phospholipid-binding protein, involved in invasion, angiogenesis and migration in cancer cells. The aims of the present study were to evaluate the expression levels of annexin A2 and E-cadherin in gastric adenocarcinoma (GAC), and to investigate the association between the expression of annexin A2 and that of E-cadherin and Ki67, in addition to various clinicopathological factors. This study included 126 patients that were histopathologically diagnosed with GAC. Tissue samples were acquired by surgical resection, and annexin A2 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction. Annexin A2, E-cadherin and Ki67 protein expression levels were detected using western blot analysis and/or immunohistochemical staining. The expression of annexin A2 mRNA and protein was significantly upregulated in the GAC tissues. Annexin A2 expression was detected in 52/126 cases (41.3%) of gastric cancer (GC), and correlations were identified between annexin A2 expression and Tumor, Node, Metastasis (TNM) stage (P=0.002), lymph node metastasis (P=0.016) and distal metastasis (P=0.005). The positive expression rates of E-cadherin and Ki67 in the tumor tissue of patients with GAC were 27.8% (35/126) and 56.2% (71/126), respectively. A negative correlation was observed between the expression of annexin A2 and E-cadherin (P<0.001). No significant association was detected between the expression levels of annexin A2 and Ki67 (P=0.801). In conclusion, upregulated annexin A2 expression was associated with lymph node metastasis, distal metastasis, advanced TNM stage and E-cadherin expression in patients with GAC. The association between the expression of annexin A2 and that of E-cadherin may indicate an underlying mechanism by which annexin A2 contributes to the metastasis in GC, and thus annexin A2 may represent a potential target for the treatment of GAC.