Upregulated EBI3 Correlates with Poor Outcome and Tumor Progression in Breast Cancer.

BACKGROUND AND AIM: So far, the understanding of the role of Epstein-Barr virus-induced gene 3 (EBI3) in breast cancer has been limited. This study uncovers the functional role and clinical significance of EBI3 in breast cancer patients.

PATIENTS AND METHODS: The expression levels of EBI3, IL-27p28, and IL-12p35 were measured by quantitative real-time reverse transcription (RT)-polymerase chain reaction (PCR). Correlations of EBI3 expression with IL-27p28 and IL-12p35 expression were analyzed using Pearson's correlation assay. The prognostic performance of EBI3 was assessed via Kaplan-Meier survival assay and Cox regression analysis.

RESULTS: EBI3 expression was increased in cancerous tissues compared with the controls (P < 0.05). This overexpression of EBI3 was correlated with lymph node metastasis and clinical stage (both P < 0.05). Besides, elevated expression of EBI3 was usually found in patients with positive lymph node metastasis (P < 0.05), and similar results were obtained in advanced clinical-stage breast cancer cases (P < 0.05). Increases in both IL-27p28 and IL-12p35 expression were identified in breast cancer tissues (all P < 0.05), and IL-12p35 expression was found to be associated with EBI3 expression (R = 0.888, P < 0.001). Survival curves revealed that high EBI3 expression was correlated with poor overall survival (log-rank P < 0.05). The Cox analysis indicated that EBI3 was an independent prognostic factor in breast cancer.

CONCLUSION: Taken together, overexpression of EBI3 was associated with poor prognosis and might be involved in the progression of breast cancer.