Renalase overexpression in ER-positive breast cancer.

ABSTRACT

OBJECTIVES: To explore the expression and pathologic significance of renalase in tumor tissues of different molecular subtypes of breast cancer. DESIGN: Immunofluorescence methods and laser confocal scanning microscope observations were used to detect expression of renalase, estrogen receptor (ER), phospho-extracellular signal-regulated kinase 1 and 2 (p-ERK1/2), and phospho-signal transducer and activator of transcription (p-STAT3) in 58 cases of breast cancer tissue, 11 normal tissues, and 14 benign fibroadenomas. Statistical analysis of its expression in different molecular subtypes of breast cancer was employed. RESULTS: Compared with control tissue (benign lesions and normal breast tissue), renalase was highly expressed in invasive breast cancer and the difference was significant (P<0.0001). Renalase was also expressed significantly higher in ER-positive breast cancer, compared with control tissue (P<0.0001). There was a positive correlation between renalase and ER expression in breast cancer tissues (R=0.7246, P<0.0001) and a positive correlation between renalase and p-ERK 1/2 expression (R=0.6599, P<0.0001). Renalase had no significant correlation with p-STAT3 protein expression. CONCLUSION: Renalase is a new molecular marker for ER-positive breast cancer and may become a potential therapeutic target for the ER-positive/HER2-negative subtype breast cancer. Renalase may promote high ER expression and breast cancer cell proliferation and growth through the p-ERK1/2 pathway.