Correlation Between High Expression of FOXA2 and Improved Overall Survival in Ovarian Cancer Patients

BACKGROUND The aim of the present work was to evaluate FOXA2 expression in ovarian cancer and to use integrated bioinformatics analysis to correlate it with patient prognosis. MATERIAL AND METHODS FOXA2 expression was evaluated in multiple cancers in The Cancer Genome Atlas database. A protein-protein interaction (PPI) network relevant to FOXA2 was constructed using the Search Tool for Retrieval of Interacting Genes/Proteins (STRIN). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed of FOXA2 and relevant genes. Correlations between overall survival (OS), disease-free survival, and FOXA2 expression were evaluated. An immunohistochemical assay (IHC) was used to test for FOXA2 protein expression in 79 ovarian cancer specimens. RESULTS FOXA2 mRNA was upregulated in colorectal, stomach, liver, and endometrial cancers. In the PPI network, 21 protein nodes and 533 edges were constructed with a local clustering coefficient of 0.698, which indicated significant PPI enrichment (P<0.01). FOXA2 and relevant genes were mainly enriched in the signaling pathways regulating pluripotency of stem cells, cancer, and AMPK. A survival analysis indicated that OS was significantly longer in patients with higher versus lower FOXA2 protein expression (HR=0.73, P<0.01). The IHC assay showed that the FOXA2 protein was mainly positively expressed in the nucleoplasm of tumor cells with brown-yellow staining. Of the 79 ovarian cancer samples, 31 (39.2%) highly expressed FOXA2. The FOXA2 gene was correlated with International Federation of Gynecology and Obstetrics staging and with lymph node metastasis (both P<0.05). CONCLUSIONS Upregulation of the FOXA2 gene was correlated with improved OS in patients with ovarian cancer and it can be used as a prognostic biomarker and potential treatment target.