title: The steroid receptor coactivator-1 regulates twist expression and promotes breast cancer metastasis.
abstract: In breast cancer, steroid receptor coactivator-1 (SRC-1) expression positively correlates with HER2 expression and poor prognosis. In mouse mammary tumor virus-polyoma middle T (PyMT) breast cancer mouse model, SRC-1 strongly promotes mammary tumor metastasis. However, the molecular targets and mechanisms that mediate the role of SRC-1 in metastasis are unknown. In this study, SRC-1 wild-type (WT) and knockout (KO) cell lines were developed from the mammary tumors of WT/PyMT and KO/PyMT mice. WT cells exhibited strong migration and invasion capabilities, reduced E-cadherin and beta-catenin epithelial markers, gained N-cadherin and vimentin mesenchymal markers, and formed undifferentiated invasive structures in three-dimensional culture. In contrast, KO cells showed slow migration and invasion, retained E-cadherin, had less N-cadherin and vimentin, and developed partially differentiated three-dimensional structures. Importantly, WT cells expressed Twist, a master regulator of metastasis, at significantly higher levels versus KO cells. SRC-1 knockdown in WT cells reduced Twist expression, whereas SRC-1 restoration in KO cells also rescued Twist expression. Furthermore, SRC-1 was found to coactivate Twist transcription through physical interaction with the transcription factor PEA3 at the proximal Twist promoter. Accordingly, Twist knockdown in WT cells increased E-cadherin and reduced cell invasion and metastasis, and Twist expression in KO cells decreased E-cadherin and increased cell invasion. SRC-1 knockdown in human breast cancer cells also decreased Twist, cell migration, and invasion. Therefore, SRC-1 promotes breast cancer invasiveness and metastasis by coactivating PEA3-mediated Twist expression. Intervention of SRC-1 function may provide new strategies to inhibit breast cancer metastasis.
authors.affiliation: Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Qin
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Liu
authors.forename: Hongwu
authors.initials: H
authors.lastname: Chen
authors.forename: Jianming
authors.initials: J
authors.lastname: Xu
mesh_terms: D000818:Animals; D015820:Cadherins / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D005260:Female; D051548:Histone Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D051379:Mice; D018345:Mice, Knockout; D009361:Neoplasm Invasiveness; D056920:Nuclear Receptor Coactivator 1; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D051879:Twist-Related Protein 1 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D015820:Cadherins; D034741:RNA, Small Interfering; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C065788:transcription factor PEA3; D051548:Histone Acetyltransferases; C538859:NCOA1 protein, human; C538861:Ncoa1 protein, mouse; D056920:Nuclear Receptor Coactivator 1