The EMT Transcription Factor ZEB2 Promotes Proliferation of Primary and Metastatic Melanoma While Suppressing an Invasive, Mesenchymal-Like Phenotype
CANCER RESEARCH
Authors: Vandamme, Niels; Denecker, Geertrui; Bruneel, Kenneth; Blancke, Gillian; Akay, Ozden; Taminau, Joachim; De Coninck, Jordy; De Smedt, Eva; Skrypek, Nicolas; Van Loocke, Wouter; Wouters, Jasper; Nittner, David; Kohler, Corinna; Darling, Douglas S.; Cheng, Phil F.; Raaijmakers, Marieke I. G.; Levesque, Mitchell P.; Mallya, Udupi Girish; Rafferty, Mairin; Balint, Balazs; Gallagher, William M.; Brochez, Lieve; Huylebroeck, Danny; Haigh, Jody J.; Andries, Vanessa; Rambow, Florian; Van Vlierberghe, Pieter; Goossens, Steven; van den Oord, Joost J.; Marine, Jean-Christophe; Berx, Geert
Abstract
Epithelial-to-mesenchymal transition (EMT)-inducing transcription factors (TF) are well known for their ability to induce mesenchymal states associated with increased migratory and invasive properties. Unexpectedly, nuclear expression of the EMT-TF ZEB2 in human primary melanoma has been shown to correlate with reduced invasion. We report here that ZEB2 is required for outgrowth for primary melanomas and metastases at secondary sites. Ablation of Zeb2 hampered outgrowth of primary melanomas in vivo, whereas ectopic expression enhanced proliferation and growth at both primary and secondary sites. Gain of Zeb2 expression in pulmonary-residing melanoma cells promoted the development of macroscopic lesions. In vivo fate mapping made clear that melanoma cells undergo a conversion in state where ZEB2 expression is replaced by ZEB1 expression associated with gain of an invasive phenotype. These findings suggest that reversible switching of the ZEB2/ZEB1 ratio enhances melanoma metastatic dissemination.
The EMT regulator ZEB2 is a novel dependency of human and murine acute myeloid leukemia
BLOOD
Authors: Li, Hubo; Mar, Brenton G.; Zhang, Huadi; Puram, Rishi V.; Vazquez, Francisca; Weir, Barbara A.; Hahn, William C.; Ebert, Benjamin; Pellman, David
Abstract
Acute myeloid leukemia (AML) is a heterogeneous disease with complex molecular pathophysiology. To systematically characterize AML's genetic dependencies, we conducted genome-scale short hairpin RNA screens in 17 AML cell lines and analyzed dependencies relative to parallel screens in 199 cell lines of other cancer types. We identified 353 genes specifically required for AML cell proliferation. To validate the in vivo relevance of genetic dependencies observed in human cell lines, we performed a secondary screen in a syngeneic murine AML model driven by the MLL-AF9 oncogenic fusion protein. Integrating the results of these interference RNA screens and additional gene expression data, we identified the transcription factor ZEB2 as a novel AML dependency. ZEB2 depletion impaired the proliferation of both human and mouse AML cells and resulted in aberrant differentiation of human AML cells. Mechanistically, we showed that ZEB2 transcriptionally represses genes that regulate myeloid differentiation, including genes involved in cell adhesion and migration. In addition, we found that epigenetic silencing of the miR-200 family microRNAs affects ZEB2 expression. Our results extend the role of ZEB2 beyond regulating epithelial-mesenchymal transition (EMT) and establish ZEB2 as a novel regulator of AML proliferation and differentiation.