Up-regulated Annexin A1 expression in gastrointestinal cancer is associated with cancer invasion and lymph node metastasis.

Annexin A1 (ANXA1) is a calcium-dependent phospholipid-linked protein, involved in anti-inflammatory effects, regulation of cellular differentiation, proliferation and apoptosis. In the present study, we investigated the expression of ANXA1 in gastric and colon cancer, and analyzed the relationship between ANXA1 expression and clinicopathological factors. ANXA1 mRNA expression in gastric and colon cancer tissues was not significantly changed compared to that in normal tissues. When ANXA1 protein expression was evaluated by immunohistochemical staining, ANXA1 expression was observed in 76 of 135 cases of gastric cancer (56.3%), and correlations were found between ANXA1 expression and depth of wall invasion (P<0.001), lymphatic invasion (P=0.023), venous invasion (P=0.002), lymph node metastasis (P=0.001) and UICC stage (P<0.001). Disease-specific survival rate was significantly lower in cases with ANXA1 expression compared to that in cases without (P=0.0053). In colon cancer, ANXA1 expression was detected in 61 of 210 cases (29.0%) and correlations were found with gender (P=0.038), lymphatic invasion (P=0.011), venous invasion (P=0.023), lymph node metastasis (P=0.042) and UICC stage (P=0.041). The disease-specific survival rate tended to be lower in cases with ANXA1 expression, although the differences were not statistically significant (P=0.6984). Our results indicate that up-regulated ANXA1 expression is involved in cancer invasion and lymph node metastasis. Furthermore, high levels of ANXA1 expression were implicated in poor prognosis of patients. ANXA1 may be applicable as a prognostic biomarker in gastric and colon cancer, and a potential target for treatment.