Dynamics of chromatin accessibility during TGF-β-induced EMT of Ras-transformed mammary gland epithelial cells

Abstract

Epithelial-mesenchymal transition (EMT) is induced by transforming growth factor (TGF)-β and facilitates tumor progression. We here performed global mapping of accessible chromatin in the mouse mammary gland epithelial EpH4 cell line and its Ras-transformed derivative (EpRas) using formaldehyde-assisted isolation of regulatory element (FAIRE)-sequencing. TGF-β and Ras altered chromatin accessibility either cooperatively or independently, and AP1, ETS, and RUNX binding motifs were enriched in the accessible chromatin regions of EpH4 and EpRas cells. Etv4, an ETS family oncogenic transcription factor, was strongly expressed and bound to more than one-third of the accessible chromatin regions in EpRas cells treated with TGF-β. While knockdown of Etv4 and another ETS family member Etv5 showed limited effects on the decrease in the E-cadherin abundance and stress fiber formation by TGF-β, gene ontology analysis showed that genes encoding extracellular proteins were most strongly down-regulated by Etv4 and Etv5 siRNAs. Accordingly, TGF-β-induced expression of Mmp13 and cell invasiveness were suppressed by Etv4 and Etv5 siRNAs, which were accompanied by the reduced chromatin accessibility at an enhancer region of Mmp13 gene. These findings suggest a mechanism of transcriptional regulation during Ras- and TGF-β-induced EMT that involves alterations of accessible chromatin, which are partly regulated by Etv4 and Etv5.

C/EBPβ regulates Vegf gene expression in granulosa cells undergoing luteinization during ovulation in female rats

“…To examine the chromatin accessibility of C/EBPβ binding region in the Vegf promoter, FAIRE-qPCR was performed as described 47,48 with some modifications. Real-time qPCR was performed to determine and calculate the FAIRE enrichment with same primers used in ChIP assay (Table 1).…”

Anti‐pyroptotic function of TGF‐β is suppressed by a synthetic dsRNA analogue in triple negative breast cancer cells

“…Molecular Oncology (2020) © 2020 The Authors. Published by FEBS Press and John Wiley & Sons Ltd. mammalian target of rapamycin (mTOR) signaling to retain the stemness of cells by prolonged TGF-β exposure, and the collaboration with jun B proto-oncogene (JUNB) to enhance cell invasion [17][18][19][20]. Likewise, the promotion of migration, invasion, bone metastasis, and cell survival are characteristics of TGF-β in TNBC [21,22].…”

Intracellular and extracellular TGF-β signaling in cancer: some recent topics

“…Indeed, chromatin accessibility and epigenetic modifications are altered during the EMT process [93,123], and emerging roles of lncRNAs in the regulation of histone modification have been revealed. A lncRNA MEG3 is induced by TGF-β and involved in the process of EMT in lung adenocarcinoma cells through recruitment of polycomb repressive complex 2 (PRC2) and its accessory component jumonji and ATrich interaction domain containing 2 (JARID2) to the promoter regions of CDH1 (encoding E-cadherin) and MIR200 family genes (encoding the miR-200 family) to induce tri-methylation of lysine 27 of histone H3 (H3K27) [78].…”

“…In mouse mammary epithelial EpH4 cells and Rastransformed EpRas cells, TGF-β and Ras alter chromatin accessibility either cooperatively or independently, and AP1, ETS, and RUNX binding motifs are enriched in the accessible chromatin regions. Oncogenic ETS family transcription factors Etv4 and Etv5, which are strongly induced by Ras signaling and bind to accessible chromatin regions in EpRas cells, may regulate transcriptional regulation during Ras-and TGF-β-induced EMT [93].…”