MARCKS protein overexpression is associated with poor prognosis in male breast cancer

BACKGROUND: Male breast cancer (MBC) is a rare and aggressive disease. Thus, identification of new therapeutic targets is crucial. OBJECTIVE: Our objective was to evaluate the protein expression of MARCKS (Myristoylated Alanine-Rich C-Kinase Substrate) in MBC and to investigate its prognostic value. MATERIALS AND METHODS: MARCKS protein expression in tumor and stromal cells was analyzed by immunohistochemistry (IHC) in a retrospective series of 96 pre-chemotherapy MBC samples and 80 normal breast samples, from Tunisian patients treated at Salah Azaiez Institute. Correlations were searched between MARCKS expression and clinicopathological features including overall survival (OS). RESULTS: MARCKS was overexpressed in epithelial tumor cells in 66% of the MBC samples versus 26% of normal samples (p= 1.40 × 10-7). Such positive MARCKS expression in epithelial tumor cells was associated with positive HER2 status (p= 4.0 × 10-3). It was associated with shorter OS in uni-and multivariate analysis. By contrast, stromal IHC MARCKS expression was correlated only with tumor grade. CONCLUSION: MARCKS tumor cell overexpression might in part explain the aggressiveness and the poor prognosis of MBC. MARCKS can represent a potential therapeutic target for MBC.