STAT3 upregulates the protein expression and transcriptional activity of β-catenin in breast cancer

International Journal of Clinical and Experimental Pathology

Pascal Gelebart¹  John Mackey¹  Raymond Lai¹  Yupo Ma¹  Hanan Armanious¹ 

关键词: STAT3;    β-catenin;    breast cancer;    MCF-7;    BT-474;   

DOI  :  

学科分类：生理学与病理学

来源: e-Century Publishing Corporation

【 摘 要 】

The expression of β-catenin detectable by immunohistochemistry has been reported to be prognostically important in breast cancer. In this study, we investigated the mechanism by which β-catenin is regulated in breast cancer cells. Our analysis of the gene promoter of β-catenin revealed multiple putative STAT3 binding sites. In support of the concept that STAT3 is a transcriptional regulator for β-catenin, results from our chromatin immunoprecipitation studies showed that STAT3 binds to two of the three potential STAT3-binding sites in the gene promoter of β-catenin (-856 and -938). Using our generated MCF-7 cell clones that carry an inducible STAT3C construct, we found that the expression levels of STAT3C significantly correlated with the transcriptional activity of β-catenin. Similar observations were made when we subjected two breast cancer cell lines (MCF-7 and BT-474) to STAT3 knock-down or transient gene transfection of STAT3C. Using immunohistochemistry, we found that pSTAT3 and β-catenin significantly correlated with each other (p=0.003, Fisher's exact test) in a cohort of primary breast tumors (n=129). To conclude, our results support the concept that STAT3 upregulates the protein expression and transcriptional activity of β-catenin in breast cancer, and these two proteins may cooperate with each other in exerting their oncogenic effects in these tumors.

【 授权许可】

Unknown