Expression of androgen receptor and embryonic stem cell associated transcript 4 in breast cancer patients with over-expression of human epidermal growth factor receptor 2 and their clinical significances

Abstract

Objective To investigate the expression and clinical significance of androgen receptor(AR) and embryonic stem cell associated transcripts 4 (NANOG) in breast cancer patients with human epidermal growth factor receptor 2 (HER-2) over-expression, and to analyze its relationship with clinicopathologic features of breast cancer. Methods 143 breast cancer patients with HER-2 over-expression were selected from the screening of 1 052 cases of invasive breast cancer according to estrogen receptor (ER), progesterone receptor (PR) and HER-2 status. The protein expression of AR and NANOG was assayed by using immunohistochemistry.The relationship between AR expression and clinicopathological features was analyzed by χ2 test. The correlation between AR expression and NANOG expression was analyzed by Spearman correlation analysis. Results The positive expression of AR was 35.7% (51/143). The AR expression was not associated with age and menstruation status (both P > 0.05), and was associated with tumor size, clinical TNM staging and lymphatic metastasis (all P < 0.05). The positive rate of NANOG were 53.1% (76/143), and NANOG proteins were negative in adjacent normal breast tissue and benign breast lesions. The positive rate of AR was 27.6% (21/76) in NANOG-positive cases, whereas the positive rate of AR was 44.8% (30/67) in NANOG-negative cases, and the difference was statistically significant (χ2= 4.526, P= 0.033). There was an inverse correlation between NANOG and AR expressions (r=-0.255, P= 0.002). Conclusion AR and NANOG may be new targets for endocrine therapy and molecular biological therapy. Key words: Breast neoplasms; Receptor, epidermal growth factor; Androgen receptor; Embryonic stem cell associated transcripts 4; Immunohistochemistry