Deregulated expression of annexin-A2 and galectin-3 is associated with metastasis in gastric cancer patients.

Gastric cancer (GC) is the second highest cause of cancer mortality worldwide. However, nowadays, most of the studies aiming to understand the gastric carcinogenesis analyzed tumors of individuals from Asian population and, thus, may not reflect the distinct biological and clinical behaviors among GC processes. Since several membrane proteins have been implicated in carcinogenesis, we aimed to evaluate ANXA2 and GAL3 role in gastric tumors and GC cell lines of individuals from northern Brazil. The cellular localization of ANXA2 and GAL3 in the GC cell lines was evaluated by immunofluorescence. Gene expression was evaluated by real-time reverse-transcription PCR and protein expression by Western blot in gastric adenocarcinomas and non-neoplastic gastric samples, as well as in GC cell lines. ANXA2 and GAL3 were presented as dots in the plasma membrane and cytoplasm in ACP02 and ACP03 cell lines. ANXA2 mRNA expression was up-regulated in 32.14 % of gastric tumors compared to non-neoplastic tissues. ANXA2 up-regulation was associated with the metastasis process in vivo and with cell line invasive behavior. GAL3 protein expression was at least 1.5-fold reduced in 50 % of gastric tumors. The reduced GAL3 expression was associated with the presence of distant metastasis and with a higher invasive phenotype in vitro. Our study shows that ANXA2 and GAL3 deregulated expression was associated with an invasive phenotype in GC cell lines and may contribute to metastasis in GC patients. Therefore, these proteins may have potential prognostic relevance for GC of individuals from northern Brazil.