β-catenin is up-expressed and predicts poor overall survival of breast cancer

Breast cancer (BC) is one of the most common malignant tumors in women.The majority of BC cells contain at least one or more up-expressed oncogene. β-catenin is found overexpressed in various epithelial cell cancers and has the function of inducing cancer cell proliferation, invasion and metastasis. However, the expression of β-catenin and its prognostic value in BC is not yet clear. In this study, mRNA and β-catenin proteins expressed in BC tissues have been explored. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) on tissue microarrays (TMA) were performed to examine the level of β-catenin mRNA and protein in BC tissues. The association between β-catenin and clinical characteristics and prognostic value were also explored. β-catenin mRNA and protein were found over-expressed in BC tissues when compared with matched tumor neighbor tissues. A high degree of β-catenin staining in BC tissues was significantly associated with tumor size, Ki67 expression, lymph node status and TNM stage. β-catenin up-expression was also able to predict poor overall survival (OS) rates. These results indicated that β-catenin may be a useful prognostic molecular biomarker for BC patients.