Reciprocal regulation of ZEB1 and AR in triple negative breast cancer cells

• Published in: Breast cancer research and treatment 2010-08, Vol.123 (1), p.139-147
• Main Authors: Graham, Tisheeka R, Yacoub, Rami, Taliaferro-Smith, LaTonia, Osunkoya, Adeboye O, Odero-Marah, Valerie A, Liu, Tongrui, Kimbro, K. Sean, Sharma, Dipali, O'Regan, Ruth M
• Format: Article
• Language: English
• Subjects: Analysis; Biological and medical sciences; Breast cancer; breast neoplasms; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Cancer cells; Cancer research; Cancer therapies; Cell Line, Tumor; Cell Movement - genetics; Cellular biology; Chromatin Immunoprecipitation; Female; Gene Expression; Gene Expression Regulation, Neoplastic; Gynecology. Andrology. Obstetrics; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Immunoblotting; Immunohistochemistry; Mammary gland diseases; Medical sciences; Medicine; Medicine & Public Health; Oncology; Preclinical Study; Protein binding; Receptor Cross-Talk - physiology; Receptor, ErbB-2 - biosynthesis; Receptors, Androgen - genetics; Receptors, Androgen - metabolism; Receptors, Estrogen - biosynthesis; Receptors, Progesterone - biosynthesis; Reverse Transcriptase Polymerase Chain Reaction; RNA; Tissue Array Analysis; Toy industry; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic; Triple negative; Tumors; ZEB1; Zinc Finger E-box-Binding Homeobox 1
• ISSN: 0167-6806; 1573-7217
• DOI: 10.1007/s10549-009-0623-7

Zinc-finger enhancer binding protein (ZEB1) is a transcription factor involved in the progression of cancer primarily through promoting epithelial to mesenchymal transition (EMT). ZEB1 represses the expression of E-cadherin by binding to E-box sequences in the promoter, thus decreasing epithelial differentiation. We show that ZEB1 and androgen receptor (AR) cross-talk in triple negative breast cancer cell lines. Chromatin immunoprecipitation analysis demonstrates that ZEB1 binds directly to the E-box located in the AR promoter. ZEB1 suppression by stably transfecting shRNA in a triple negative breast cancer cell line resulted in a decrease of AR mRNA, protein, and AR downstream targets. ZEB1 knockdown in triple negative breast cancer cells sensitized the cells to bicalutamide by reducing migration compared to the control cells. Conversely, blockade of AR signaling with bicalutamide resulted in a suppression of ZEB1 protein expression in two triple negative breast cancer cell lines. Furthermore, using a breast cancer tissue microarray, a majority of triple negative breast cancers exhibit positive staining for both ZEB1 and AR. Taken together, these results indicate that ZEB1 and AR regulate each other to promote cell migration in triple negative breast cancer cells.