Stathmin1 expression is associated with aggressive phenotypes and cancer stem cell marker expression in breast cancer patients

Stathmin1 (STMN1) regulates progression in various cancers. The present study aimed to determine the relationship between STMN1 expression and several cancer-related markers in breast cancer. Using immunohistochemistry, we evaluated STMN1, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, epidermal growth factor receptor (EGFR), CK5/6, CD44, CD24, aldehyde dehydrogenase 1, E-cadherin, epithelial cell adhesion molecule, and vimentin in 237 breast cancer patients and the clinical significance of STMN1. STMN1 expression was evaluated in 51 breast cancer cell lines, and the prognostic value of STMN1 was calculated. Higher STMN1 expression was detected in cancer tissues and was predominantly localized in the cytoplasm. High STMN1 expression was associated with the triple negative subtype, nuclear grade progression, high expression of Ki-67, EGFR, CK5/6, E-cadherin and high CD44/low CD24. According to gene expression-based outcome for breast cancer online and the Kaplan-Meier plotter, STMN1 expression was higher in basal-type cell lines than in luminal-type cell lines, and overall survival and post-progression survival in the high STMN1 expression breast cancer patients were shorter than in low STMN1 expression patients. High STMN1 expression is a possible marker of breast cancer aggressiveness in association with proliferation, phenotype and cancer stem cell type.