An autocrine TGF-β/ZEB/miR-200 signaling network regulates establishment and maintenance of epithelial-mesenchymal transition

• DOI: 10.1091/mbc.e11-02-0103
• Publication Date: 2011-03-16T20:55:53Z
• Authors: Philip A. Gregory; Cameron P. Bracken; Eric Smith; Andrew G. Bert; Josephine A. Wright; Suraya Roslan; Melanie Morris; Leila Wyatt; Gelareh Farshid; Yat-Yuen Lim; Geoffrey J. Lindeman; M. Frances Shannon; Paul A. Drew; Yeesim Khew-Goodall; Gregory J. Goodall
• Keywords: homeodomain proteins; 0301 basic medicine; dogs; 570; Cofilin 2; Epithelial-Mesenchymal Transition; physiological; epithelial-mesenchymal transition; dna methylation; feedback; Breast Neoplasms; carcinoma; Cell Line; 03 medical and health sciences; Dogs; Transforming Growth Factor beta; transcription factors; breast neoplasms; up-regulation; Animals; Humans; humans; micrornas; autocrine communication; breast; repressor proteins; Zinc Finger E-box Binding Homeobox 2; transforming growth factor beta; Feedback, Physiological; Homeodomain Proteins; Carcinoma, Ductal, Breast; 500; cell line; Articles; DNA Methylation; ductal; Up-Regulation; animals; Repressor Proteins; Autocrine Communication; MicroRNAs; female; cofilin 2; Female; signal transduction; Signal Transduction; Transcription Factors

Epithelial-mesenchymal transition (EMT) is a form of cellular plasticity that is critical for embryonic development and tumor metastasis. A double-negative feedback loop involving the miR-200 family and ZEB (zinc finger E-box-binding homeobox) transcription factors has been postulated to control the balance between epithelial and mesenchymal states. Here we demonstrate using the epithelial Madin Darby canine kidney cell line model that, although manipulation of the ZEB/miR-200 balance is able to repeatedly switch cells between epithelial and mesenchymal states, the induction and maintenance of a stable mesenchymal phenotype requires the establishment of autocrine transforming growth factor-β (TGF-β) signaling to drive sustained ZEB expression. Furthermore, we show that prolonged autocrine TGF-β signaling induced reversible DNA methylation of the miR-200 loci with corresponding changes in miR-200 levels. Collectively, these findings demonstrate the existence of an autocrine TGF-β/ZEB/miR-200 signaling network that regulates plasticity between epithelial and mesenchymal states. We find a strong correlation between ZEBs and TGF-β and negative correlations between miR-200 and TGF-β and between miR-200 and ZEBs, in invasive ductal carcinomas, consistent with an autocrine TGF-β/ZEB/miR-200 signaling network being active in breast cancers.