LEF1 Enhances the Progression of Colonic Adenocarcinoma via Remodeling the Cell Motility Associated Structures

Lymphoid enhancer-binding factor 1 (LEF1) is a key transcription factor mediating the Wnt signaling pathway. LEF1 is a regulator that is closely associated with tumor malignancy and is usually upregulated in cancers, including colonic adenocarcinoma. The underlying molecular mechanisms of LEF1 regulation for colonic adenocarcinoma progression remain unknown. To explore it, the LEF1 expression in caco2 cells was inhibited using an shRNA approach. The results showed that downregulation of LEF1 inhibited the malignancy and motility associated microstructures, such as polymerization of F-actin, β-tubulin, and Lamin B1 in caco2 cells. LEF1 inhibition suppressed the expression of epithelial/endothelial-mesenchymal transition (EMT) relevant genes. Overall, the current results demonstrated that LEF1 plays a pivotal role in maintaining the malignancy of colonic adenocarcinoma by remodeling motility correlated microstructures and suppressing the expression of EMT-relevant genes. Our study provided evidence of the roles LEF1 played in colonic adenocarcinoma progression, and suggest LEF1 as a potential target for colonic adenocarcinoma therapy.

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LEF-1 Regulates C/EBP α Expression and Neutrophil Differentiation in Normal Myelopoiesis and Congenital Neutropenia by a β-Catenin Independent Mechanism.

Blood ◽

10.1182/blood.v108.11.500.500 ◽

2006 ◽

Vol 108 (11) ◽

pp. 500-500 ◽

Cited By ~ 1

Author(s):

Julia Skokowa ◽

Murat Uenalan ◽

Axel Schambach ◽

Michaela Scherr ◽

Matthias Eder ◽

...

Keyword(s):

Transcription Factor ◽

Molecular Mechanisms ◽

Wnt Signaling Pathway ◽

Binding Domain ◽

Granulocytic Differentiation ◽

Congenital Neutropenia ◽

Cd34 Cells ◽

Binding Factor ◽

Myeloid Progenitors

Abstract Lymphoid enhancer-binding factor 1 (LEF-1) belongs to the canonical Wnt signaling pathway acting in transcriptional complexes with β-catenin. LEF-1 can also act independent of β-catenin (i.e. in the TGF-β or Notch pathway). Additionally, recent studies described LEF-1 dominant negative isoform (dnLEF-1), which lack the β-catenin binding domain and functions as either a transcriptional repressor or activator. To date, analysis of the role of LEF-1 in hematopoiesis has been restricted to the lymphoid compartment. Previously we described the crucial role of lymphoid enhancer-binding factor 1 (LEF-1) in granulopoiesis. We found that LEF-1 mediates proliferation, survival, and differentiation of granulocyte progenitor cells. Moreover, abrogated LEF-1 expression is one of the pathomechanism of severe congenital neutropenia CN (Skokowa et al., Nature Medicine, in press). Based on these findings, we aimed to characterize the molecular mechanisms of LEF-1 in the regulation of granulocytic differentiation. C/EBPα is well known as a key transcription factor in granulopoiesis and we found it to be a target gene directly regulated by LEF-1. A screen of the known 566 bp upstream promoter of C/EBPα gene revealed a putative LEF-1 binding site (− 559 bp to − 538 bp). We confirmed LEF-1 binding to C/EBPα promoter in nuclear extracts from CD34+ and CD33+ cells in the transcription factor binding NoShift and ChIP assays. Interestingly, LEF-1 binds to the C/EBPα promoter more efficiently in CD33+ myeloid progenitors than in CD34+ cells. The direct regulation of C/EBPα by LEF-1 was further confirmed in functional studies. We found that in line with down-regulation of LEF-1, expression of C/EBPα was also significantly reduced in CD33+ myeloid progenitors of CN patients. Moreover, LEF-1 rescue of these cells resulted in a marked up-regulation of C/EBPα mRNA expression and in vitro restoration of defective granulocytic differentiation. Remarkably, transduction of CN CD33+ cells with dnLEF-1 isoform, which lacks the ß-catenin-binding domain, resulted in up-regulation of C/EBPα to a similar degree as it was observed with full-length LEF-1. A direct regulatory link between LEF-1 and C/EBPα was additionally confirmed in LEF-1 inhibition experiments. C/EBPα expression was significantly down-regulated in CD34+ cells of healthy individuals, transduced with LEF-1 shRNA. Therefore, we propose that LEF-1 is a key regulator of myeloid differentiation acting in a β-catenin-independent manner, similar as it is known for LEF-1 regulation of T-lymphocyte development.

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Molecular regulation of Snai2 in development and disease

Journal of Cell Science ◽

10.1242/jcs.235127 ◽

2019 ◽

Vol 132 (23) ◽

Author(s):

Wenhui Zhou ◽

Kayla M. Gross ◽

Charlotte Kuperwasser

Keyword(s):

Transcription Factor ◽

Cell Biology ◽

Molecular Mechanisms ◽

Epithelial To Mesenchymal Transition ◽

Zinc Finger Protein ◽

Main Role ◽

Biological Processes ◽

Developmental Defects ◽

Mesenchymal Transition ◽

Damage Repair

ABSTRACT The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

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ZEB2 regulates a transcriptional network of calcium-handling genes in the injured heart

European Heart Journal ◽

10.1093/ehjci/ehaa946.3633 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

M Gladka ◽

A De Leeuw ◽

A Kohela ◽

B Molenaar ◽

D Versteeg ◽

...

Keyword(s):

Heart Failure ◽

Transcription Factor ◽

Cardiac Function ◽

Cardiac Dysfunction ◽

Molecular Mechanisms ◽

Critical Role ◽

Calcium Handling ◽

Funding Source ◽

Post Injury ◽

Mesenchymal Transition

Abstract Intracellular calcium (Ca2+) overload is known to play a critical role in the development of cardiac dysfunction. Despite the remarkable progress in managing the progression of the disease, the development of effective therapies for heart failure (HF) remains challenging. Therefore, it is of great importance to understand the molecular mechanisms that maintain calcium level and contractility in homeostatic conditions. Here we identified a transcription factor ZEB2 that regulates the expression of numerous contractile and calcium-related genes. Zinc finger E-box-binding homeobox2 (ZEB2) is a transcription factor that plays a role during early fetal development and epithelial-to-mesenchymal transition (EMT); however, its function in the heart remains to be determined. Recently, we found that ZEB2 is upregulated in murine cardiomyocytes shortly after an ischemic event, but returns to baseline levels as the disease progresses. Gain- and loss-of-function genetic mouse models revealed the necessity and sufficiency of ZEB2 to maintain proper cardiac function after ischemic injury. We show that cardiomyocyte-specific ZEB2 overexpression (Zeb2 cTG) protected from ischemia-induced diastolic dysfunction and attenuated the structural remodeling of the heart. Moreover, RNA-sequencing of Zeb2 cTG hearts post-injury implicated ZEB2 in the regulation of numerous calcium-handling and contractile-related genes when compared to wildtype mice. Mechanistically, ZEB2 overexpression increased the phosphorylation of phospholamban (PLN) at both serine-16 and threonine-17, implying enhanced activity of the sarcoplasmic reticulum Ca2+-ATPase (SERCA2A), thereby augmenting contractility. Improved cardiac function in ZEB2-overexpressing hearts correlated with higher expression of several sarcomeric proteins like myosin-binding protein C3 (MYBPC3), desmin (DES) and myosin regulatory light chain 2 (MYL2) further contributing to the observed protective phenotype. Furthermore, we observed a decrease in the activity of Ca2+-depended calcineurin/NFAT signaling, which is the main driver of pathological cardiac remodeling. Conversely to Zeb2 cTg mice, loss of ZEB2 from cardiomyocytes perturbed the expression of calcium- and contractile-related proteins and increased the activity of calcineurin/NFAT pathway, exacerbating cardiac dysfunction. Together, we show that ZEB2 is a central regulator of contractile and calcium-handling components, consequently mediating contractility in the mammalian heart. Further mechanistic understanding of the role of ZEB2 in the regulation of calcium homeostasis in cardiomyocytes is a critical step towards the development of improved therapies for various forms of heart failure. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): DR. E. Dekker from Dutch Heart Foundation

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MicroRNA-375: Potential cancer suppressor and therapeutic drug

Bioscience Reports ◽

10.1042/bsr20211494 ◽

2021 ◽

Author(s):

Jiahui Wei ◽

Yiran Lu ◽

Ruiqing Wang ◽

Xiangzhu Xu ◽

Qing Liu ◽

...

Keyword(s):

Signaling Pathway ◽

Noncoding Rna ◽

Molecular Mechanisms ◽

Transforming Growth Factor ◽

Epithelial Mesenchymal Transition ◽

Wnt Signaling Pathway ◽

Human Tumor ◽

Therapeutic Drug ◽

Mesenchymal Transition

MiR-375 is a conserved noncoding RNA that is known to be involved in tumor cell proliferation, migration, and drug resistance. Previous studies have shown that miR-375 affects the epithelial-mesenchymal transition (EMT) of human tumor cells via some key transcription factors, such as Yes-associated protein 1 (YAP1), Specificity protein 1 (SP1) -and signaling pathways (Wnt signaling pathway, nuclear factor kappa B (NF-kB) pathway and transforming growth factor β (TGF-β) signaling pathway) and is vital for the development of cancer. Additionally, recent studies have identified miRNA delivery system carriers for improved in vivo transportation of miR-375 to specific sites. Here, we discussed the role of miR-375 in different types of cancers, as well as molecular mechanisms, and analyzed the potential of miR-375 as a molecular biomarker and therapeutic target to improve the efficiency of clinical diagnosis of cancer.

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The epithelial-mesenchymal transcription factor SNAI1 represses transcription of the tumor suppressor miRNA let-7 in cancer

10.1101/2020.11.04.368688 ◽

2020 ◽

Author(s):

H Wang ◽

E Chirshev ◽

N Hojo ◽

T Suzuki ◽

A Bertucci ◽

...

Keyword(s):

Ovarian Cancer ◽

Transcription Factor ◽

Stem Cell ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Epithelial Mesenchymal Transition ◽

Tumor Burden ◽

Cell Phenotype ◽

Mesenchymal Transition

AbstractWe aimed to determine the mechanism of epithelial-mesenchymal transition (EMT)-induced stemness in cancer cells. Cancer relapse and metastasis are caused by rare stem-like cells within tumors. Studies of stem cell reprogramming have linked let-7 repression and acquisition of stemness with the EMT factor, SNAI1. The mechanisms for the loss of let-7 in cancer cells are incompletely understood. In four carcinoma cell lines from breast cancer, pancreatic cancer and ovarian cancer and in ovarian cancer patient-derived cells, we analyzed stem cell phenotype and tumor growth via mRNA, miRNA, and protein expression, spheroid formation, and growth in patient-derived xenografts. We show that treatment with EMT-promoting growth factors or SNAI1 overexpression increased stemness and reduced let-7 expression, while SNAI1 knockdown reduced stemness and restored let-7 expression. Rescue experiments demonstrate that the pro-stemness effects of SNAI1 are mediated via let-7. In vivo, nanoparticle-delivered siRNA successfully knocked down SNAI1 in orthotopic patient-derived xenografts, accompanied by reduced stemness and increased let-7 expression, and reduced tumor burden. Chromatin immunoprecipitation demonstrated that SNAI1 binds the promoters of various let-7 family members, and luciferase assays revealed that SNAI1 represses let-7 transcription. In conclusion, the SNAI1/let-7 axis is an important component of stemness pathways in cancer cells, and this study provides a rationale for future work examining this axis as a potential target for cancer stem cell-specific therapies.Novelty and ImpactThis study provides new insight into molecular mechanisms by which EMT transcription factor SNAI1 exerts its pro-stemness effects in cancer cells, demonstrating its potential as a stem cell-directed target for therapy. In vitro and in vivo, mesoporous silica nanoparticle-mediated SNAI1 knockdown resulted in restoration of let-7 miRNA, inhibiting stemness and reducing tumor burden. Our studies validate in vivo nanoparticle-delivered RNAi targeting the SNAI1/let-7 axis as a clinically relevant approach.

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SNAI1, an endothelial–mesenchymal transition transcription factor, promotes the early phase of ocular neovascularization

Angiogenesis ◽

10.1007/s10456-018-9614-9 ◽

2018 ◽

Vol 21 (3) ◽

pp. 635-652 ◽

Cited By ~ 18

Author(s):

Jia-Xing Sun ◽

Tian-Fang Chang ◽

Man-Hong Li ◽

Li-Juan Sun ◽

Xian-Chun Yan ◽

...

Keyword(s):

Transcription Factor ◽

Early Phase ◽

Mesenchymal Transition ◽

Ocular Neovascularization ◽

Endothelial Mesenchymal Transition

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The mechanism of TGF-β/miR-155/c-Ski regulates endothelial–mesenchymal transition in human coronary artery endothelial cells

Bioscience Reports ◽

10.1042/bsr20160603 ◽

2017 ◽

Vol 37 (4) ◽

Cited By ~ 21

Author(s):

Juan Wang ◽

Wen He ◽

Xiao Xu ◽

Liping Guo ◽

Yin Zhang ◽

...

Keyword(s):

Endothelial Cells ◽

Coronary Artery ◽

Molecular Mechanisms ◽

Cardiac Fibrosis ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Human Coronary Artery ◽

Mesenchymal Transition ◽

Twist Expression ◽

Endothelial Mesenchymal Transition

Human coronary artery endothelial cells (HCAECs) have the potential to undergo fibrogenic endothelial–mesenchymal transition (EndMT), which results in matrix-producing fibroblasts and thereby contributes to the pathogenesis of cardiac fibrosis. Recently, the profibrotic cytokine transforming growth factor-β (TGF-β) is shown to be the crucial pathogenic driver which has been verified to induce EndMT. C-Ski is an important regulator of TGF-β signaling. However, the detailed role of c-Ski and the molecular mechanisms by which c-Ski affects TGF-β-induced EndMT in HCAECs are not largely elucidated. In the present study, we treated HCAECs with TGF-β of different concentrations to induce EndMT. We found that overexpression of c-Ski in HCAECs either blocked EndMT via hindering Vimentin, Snail, Slug, and Twist expression while enhancing CD31 expression, with or without TGF-β treatment. In contrast, suppression of c-Ski further enhanced EndMT. Currently, miRNA expression disorder has been frequently reported associating with cardiac fibrosis. By using online tools, we regarded miR-155 as a candidate miRNA that could target c-Ski, which was verified using luciferase assays. C-Ski expression was negatively regulated by miR-155. TGF-β-induced EndMT was inhibited by miR-155 silence; the effect of TGF-β on Vimentin, CD31, Snail, Slug, and Twist could be partially restored by miR-155. Altogether, these findings will shed light on the role and mechanism by which miR-155 regulates TGF-β-induced HCAECs EndMT via c-Ski to affect cardiac fibrosis, and miR-155/c-Ski may represent novel biomarkers and therapeutic targets in the treatment of cardiac fibrosis.

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The emerging roles of Oct4 in tumor-initiating cells

AJP Cell Physiology ◽

10.1152/ajpcell.00212.2015 ◽

2015 ◽

Vol 309 (11) ◽

pp. C709-C718 ◽

Cited By ~ 52

Author(s):

Ying-Jie Wang ◽

Meenhard Herlyn

Keyword(s):

Stem Cells ◽

Transcription Factor ◽

Pluripotent Stem Cells ◽

Molecular Mechanisms ◽

Target Genes ◽

Large Body ◽

Tumor Initiating Cells ◽

Self Renewal ◽

Mesenchymal Transition ◽

Main Challenge

Octamer-binding transcription factor 4 (Oct4), a homeodomain transcription factor, is well established as a master factor controlling the self-renewal and pluripotency of pluripotent stem cells. Also, a large body of research has documented the detection of Oct4 in tumor cells and tissues and has indicated its enrichment in a subpopulation of undifferentiated tumor-initiating cells (TICs) that critically account for tumor initiation, metastasis, and resistance to anticancer therapies. There is circumstantial evidence for low-level expression of Oct4 in cancer cells and TICs, and the participation of Oct4 in various TIC functions such as its self-renewal and survival, epithelial-mesenchymal transition (EMT) and metastasis, and drug resistance development is implicated from considerable Oct4 knockdown and overexpression-based studies. In a few studies, efforts have been made to identify Oct4 target genes in TICs of different sources. Based on such information, Oct4 in TICs appears to act via mechanisms quite distinct from those in pluripotent stem cells, and a main challenge for future studies is to unravel the molecular mechanisms of action of Oct4, particularly to address the question on how such low levels of Oct4 may exert its functions in TICs. Acquiring cells from their native microenvironment that are of high enough quantity and purity is the key to reliably analyze Oct4 functions and its target genes in TICs, and the information gained may greatly facilitate targeting and eradicating those cells.

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Wnt2 Contributes to the Development of Atherosclerosis

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.751720 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jinyu Zhang ◽

Samuel Rojas ◽

Sanjay Singh ◽

Phillip R. Musich ◽

Matthew Gutierrez ◽

...

Keyword(s):

Signaling Pathway ◽

Molecular Mechanisms ◽

Wnt Signaling Pathway ◽

Chronic Inflammatory Disease ◽

Aortic Endothelial Cells ◽

Mesenchymal Transition ◽

Atherosclerotic Lesions ◽

Endothelial To Mesenchymal Transition

Atherosclerosis, is a chronic inflammatory disease, characterized by the narrowing of the arteries resulting from the formation of intimal plaques in the wall of arteries. Yet the molecular mechanisms responsible for maintaining the development and progression of atherosclerotic lesions have not been fully defined. In this study, we show that TGF-β activates the endothelial-to-mesenchymal transition (EndMT) in cultured human aortic endothelial cells (HAECs) and this transition is dependent on the key executor of the Wnt signaling pathway in vitro. This study presents the first evidence describing the mechanistic details of the TGF-β-induced EndMT signaling pathway in HAECs by documenting the cellular transition to the mesenchymal phenotype including the expression of mesenchymal markers α-SMA and PDGFRα, and the loss of endothelial markers including VE-cadherin and CD31. Furthermore, a short hairpin RNA (shRNA) screening revealed that Wnt2 signaling is required for TGF-β-mediated EndMT of HAECs. Also, we found that LDLR−/− mice fed on a high-fat western-type diet (21% fat, 0.2% cholesterol) expressed high levels of Wnt2 protein in atherosclerotic lesions, confirming that this signaling pathway is involved in atherosclerosis in vivo. These findings suggest that Wnt2 may contribute to atherosclerotic plaque development and this study will render Wnt2 as a potential target for therapeutic intervention aiming at controlling atherosclerosis.

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Transcription factor/DNA interactions visualized by electron spectroscopic imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122654 ◽

1992 ◽

Vol 50 (1) ◽

pp. 450-451

Author(s):

David P. Bazett-Jones ◽

Mark L. Brown

Keyword(s):

Transcription Factor ◽

Dna Sequences ◽

Transcription Initiation ◽

Molecular Mechanisms ◽

Phosphorus Content ◽

Spectroscopic Imaging ◽

Electron Spectroscopic Imaging ◽

Dna Backbone ◽

Two Parameters ◽

High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

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