Negative feedback loop between ZBTB7A and TGF-β in breast cancer.

Zinc finger and BTB domain containing 7A (ZBTB7A) is aberrantly expressed in breast cancer, but the involvement of ZBTB7A in breast cancer remains controversial. Transforming growth factor-β (TGF-β) is a pleiotropic cytokine which promotes breast cancer metastasis. ZBTB7A and TGF-β are important factors in tumor development. However, the association between ZBTB7A and TGF-β in breast cancer remains unknown. The results of the present study revealed that TGF-β1 induced the expression of ZBTB7A via the phosphoinositide 3-kinase-protein kinase B signaling pathway in human breast cancer cells, and ZBTB7A inhibited the expression of TGF-β1 through indirectly suppressing the promoter activity of TGF-β1. Furthermore, no significant correlation between the expression of ZBTB7A and TGF-β1 were identified in breast cancer tissues using tissue microarray assay and human cancer genomics analysis. These results have identified a negative feedback loop between ZBTB7A and TGF-β signaling, suggesting ZBTB7A as a potential modulator of breast cancer metastasis. Thus, the results of the present study suggested that ZBTB7A is a potential prognostic biomarker for breast cancer.