Expression of FOXO1 is associated with GATA3 and Annexin-1 and predicts disease-free survival in breast cancer

Abstract

Purpose: To determine the prognostic value of FOXO1, GATA3 and Annexin-1 expression in breast cancer.

Methods: Tissue microarray and individual paraffin tissue slides from 131 patients were used for the study. The association of FOXO1, GATA3 and Annexin-1 expression with clinicopathological features of breast cancer and disease outcome was examined in retrospective samples. Kaplan-Meier survival curves and Cox regression with multivariate analysis were used for assessing the relative risk (RR) and disease-free survival (DFS). The expression of FOXO1, GATA3 and Annexin-1 were determined by immunohistochemistry and the association among the three proteins was analyzed by Logistic regression analysis.

Results: The nuclear expression of FOXO1 was observed in most of the normal breast tissues and 51.3% of the malignant breast tissues. GATA3 and Annexin-1 were expressed at 73% and 24.6% respectively in breast cancer tissues. The expression of FOXO1, GATA3 and Annexin-1 were all inversely correlated with lymph node-positive tumors. Both FOXO1 and Annexin-1 expression were also inversely associated with HER2-overexpressing tumors. FOXO1 expression was significantly associated with both GATA3 and Annexin-1 expression. In addition, Multivariate analyses confirm that only FOXO1 levels independently predict DFS.

Conclusion: FOXO1 expression in breast cancer is regulated by the PI3K/Akt pathway. The expression of FOXO1 is also associated with GATA3 and/or Annexin-1. Restoring or targeting FOXO1 to the cell nucleus in breast cancer tissues may improve response to therapy and disease outcome. Further clinical studies are warranted to test this hypothesis.

Keywords: FOXO1; GATA3; annexin-1; breast cancer; survival.

Figure 1

FOXO1, GATA3 and Annexin-1 expression in non-cancer and cancer tissues. A-1 and A-8 were normal breast tissue from a non-cancer subject and B-1 and B-8 were invasive ductal carcinoma from a breast cancer patient with ER/PR negative and HER2 positive tumor. A-1 to A-4 and B-1 to B4 were low-power and A-5 to A-8 and B-5 to B-8 were high-power. The red arrows indicated positive expression of FOXO1 and GATA3 in nuclear of epithelial cells and Annexin-1 in the myoepithelila cells. The black arrows indicated membrane and cytoplasm expression of FOXO1 and GATA3 and the storm tissue expression of Annexin-1.

Figure 2

DFS and FOXO1 expression. (A) Kaplan-Meier survival curves were used to compare the 5-year DFS between the FOXO1 positive and negative tumors. The differences between the curves were estimated by log-rank test and p<0.05 was considered statistically significant. (B to D), The RR of shorter DFS was determined by univariate Cox regression analysis. (B) The patients were grouped as (I) HER2-/pAkt+/FOXO1-, (II) HER2+/pAkt+/FOXO1- and (III) HER2-/pAkt-/FOXO1+ tumors. The RR was compared to (III) HER2-/pAkt-/FOXO1+ group. (C and D), The patients were first grouped as FOXO1-positive and FOXO1-negative and then RR of shorter DFS in GATA3-negative tumor was compared with that in GATA3-positive tumor in each group (C); or Annexin-1-negative tumor was compared with Annexin-1 -positive tumor (D) in each group. p<0.05 was considered statistically significant only.