title: ZEB1 is neither sufficient nor required for epithelial-mesenchymal transition in LS174T colorectal cancer cells.
abstract: Epithelial-mesenchymal transition (EMT) is implicated in metastases formation and acquired therapy resistance in several tumor entities. The two transcription factors SNAIL1 and ZEB1 are thought to be master regulators of EMT and to form a core regulatory network required for EMT-associated transcriptional reprogramming. Yet, inducible EMT models show the sequential upregulation first of SNAIL1 and only subsequently of ZEB1. Therefore, SNAIL1 and ZEB1 might be differentially needed for the onset and propagation of EMT. Here we used LS174T colorectal adenocarcinoma cells which do not express endogenous EMT-inducing transcription factors, to investigate whether ZEB1 is an obligatory downstream mediator of Snail1-induced EMT, and to test whether ZEB1 could elicit an EMT in a background of naïve epithelial cells by itself. However, CRISPR/Cas9-mediated knockout of ZEB1 did not affect the ability of ectopically expressed Snail1 to trigger a complete EMT in ZEB1-deficient LS174T cells. In contrast to Snail1, ectopic ZEB1 had only minor effects on cell morphology and invasive growth in three-dimensional spheroid cultures. In agreement with this, expression of ZEB1 did not lead to repression of epithelial marker genes, and mesenchymal markers were not upregulated by ZEB1. Likewise, ectopic ZEB1 expression did not confer increased chemoresistance. We conclude that ZEB1 is neither required nor sufficient for EMT in LS174T colorectal cancer cells.
authors.affiliation: Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Jägle
authors.affiliation: Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Dertmann
authors.affiliation: Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Schrempp
authors.affiliation: Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Germany; Faculty of Biology, University of Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, Germany. Electronic address: andreas.hecht@mol-med.uni-freiburg.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hecht
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D015703:Antigens, CD; D064113:CRISPR-Cas Systems; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D015179:Colorectal Neoplasms / Q000378:metabolism*; D004318:Doxycycline / Q000737:chemistry; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009361:Neoplasm Invasiveness; D009944:Organoplatinum Compounds / Q000737:chemistry*; D000077150:Oxaliplatin; D000071250:Snail Family Transcription Factors / Q000378:metabolism; D018874:Spheroids, Cellular; D015854:Up-Regulation; D000071799:Zinc Finger E-box-Binding Homeobox 1 / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; D009944:Organoplatinum Compounds; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D000077150:Oxaliplatin; D004318:Doxycycline
keywords: Colorectal cancer; Epithelial-mesenchymal transition; Genome editing; SNAIL1; Tumor cell invasion; ZEB1