• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1489-1495
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• 2014

Wnt is a powerful signaling pathway that plays a crucial role in cell fate determination, survival, proliferation and motility during development, in adult tissues and cancer. The aims of the present study were three fold: i) to assess Wnt11 immunoexpression and its possible relationship with Wnt5a in high- and low-grade human serous ovarian cancer (HGSC and LGSC) specimens; ii) to assess Wnt11 expression levels in Wnt5a overexpressing SKOV-3 cells; iii) to reveal the role of Wnt11 in viability, adhesion, migration and invasion of SKOV-3 cells using recombinant human Wnt11 (rhWnt11). Immunohistochemistry revealed a significant difference in Wnt11 expression between HGSC and LGSC groups (p=0.001). Moreover, a positive correlation was observed between Wnt5a and Wnt11 expression in the HGSC (r=0.713, p=0.001), but not the LGSC group. The expression of Wnt11 was decreased by 35% in Wnt5a overexpressing cells (SKOV-3/Wnt5a) compared to mock controls. Similarly Wnt11 expression levels were decreased by 47% in the presence of exogenous Wnt5a compared to untreated cells. In the presence of rhWnt11, 31% increased cell viability (p<0.001) and 21% increased cell adhesion to matrigel (p<0.01) were observed compared to control. Cell migration was increased by 1.6-fold with rhWnt11 as revealed by transwell migration assay (p<0.001). However, 45% decreased cell invasion was observed in the presence of rhWnt11 compared to control (p<0.01). Our results may suggest that differential Wnt11 immunoexpression in HGSC compared to LGSC could play important roles in serous ovarian cancer progression and may be modulated by Wnt5a expression levels.

• Development and Reproduction
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• v.11 no.3
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• pp.141-153
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• 2007

The Wnt signaling pathway regulates cell proliferation and differentiation during development of multicellular organisms and plays pivotal roles in the maintenance of homeostasis in adult tissues. Therefore misregulation of Wnt signaling could be a pathogenesis of diverse human diseases such as cancers. Recently, the list of diseases that may be linked to the misregulation of Wnt signaling has exploded and more people are getting interested in the way of controlling Wnt signaling. There are a lot of review papers, however, since most of them have focused on specific issues for experts in Wnt signaling it may be difficult for new comers to understand the overall background and current status of Wnt signaling. In this review, we present data and interpretations for the overall processes of Wnt signal transduction to understand the past and current status of Wnt signaling.

• BMB Reports
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• v.48 no.9
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• pp.525-530
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• 2015

Activation of the Wnt/β-catenin pathway plays a pathogenic role in age-related macular degeneration (AMD) and is thus a potential target for the development of therapeutics for this disease. Here, we demonstrated that Wnt5a antagonized β-catenin response transcription (CRT) induced with Wnt3a by promoting β-catenin phosphorylation at Ser33/Ser37/Thr41 and its subsequent degradation in human retinal pigment epithelial (RPE) cells. Wnt5a decreased the levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α(TNF-α), and nuclear factor-κB (NF-κB), which was up-regulated by Wnt3a. Furthermore, Wnt5a increased E-cadherin expression and decreased cell migration by down-regulating Snail expression, thereby abrogating the Wnt3a-induced epithelial-mesenchymal transition (EMT) in human RPE cells. Our findings suggest that Wnt5a suppresses the pathogenic effects of canonical Wnt signaling in human RPE cells by promoting β-catenin phosphorylation and degradation. Therefore, Wnt5a has significant therapeutic potential for the treatment of AMD. [BMB Reports 2015; 48(9): 525-530]

• Journal of Life Science
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• v.23 no.7
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• pp.947-954
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• 2013

The Wnt/${\beta}$-catenin signaling pathway is an evolutionarily conserved signaling network that is critical for embryonic development and adult tissue maintenance. In addition, aberrant activation of Wnt/${\beta}$-catenin signaling is implicated in the formation of various human diseases, including cancers. Thus, study of the underlying molecular mechanism of Wnt/${\beta}$-catenin signaling regulation is important to understand and treat diseases. Inhibition of aberrant Wnt pathway activity in cancer cell lines efficiently blocks their growth, highlighting the great potential of therapeutics designed to achieve this in cancer patients. Recently, protein kinases have emerged as key regulating components of Wnt/${\beta}$-catenin signaling. In this review, we provide the most recent information on Wnt/${\beta}$-catenin signaling, describe protein kinases involved in Wnt/${\beta}$-catenin signaling, and discuss their potential as drug targets.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.50-56
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• 2012

The Wnt/${\beta}$-catenin signaling pathway regulates diverse developmental processes and adult tissue homeostasis. Inappropriate regulation of this pathway has been associated with human diseases, such as cancers, osteoporosis, and Alzheimer's disease. Using a cell-based chemical screening with natural compounds, we discovered silybin, a plant flavonoid isolated from the Silybum marianum, which activated the Wnt/${\beta}$-catenin signaling pathway in a synergy with Wnt3a-conditioned medium (Wnt3a-CM). In the presence of Wnt3a-CM, silybin up-regulated ${\beta}$-catenin response transcription (CRT) in HEK293-FL reporter cells and 3T3-L1 preadipocytes through stabilization of intracellular ${\beta}$-catenin protein. Silybin and Wnt3a-CM synergistically reduced expression of important adipocyte marker genes including peroxisome-proliferator-activated $receptor{\gamma}$ ($PPAR{\gamma}$) and CAATT enhancer-binding protein ${\alpha}$ (C/$EBP{\alpha}$) in 3T3-L1 preadipocytes, accompanied by the activation of Wnt/${\beta}$-catenin signaling pathway. Taken together, our findings indicate that silybin is a small-molecule synergist of the Wnt/${\beta}$-catenin signaling pathway and can be used as a controllable reagent for investigating biological processes that involve the Wnt/${\beta}$-catenin signaling pathway.

• BMB Reports
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• v.41 no.7
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• pp.485-494
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• 2008

The Wnt signaling network, which is composed of Wnt ligands, receptors, antagonists, and intracellular signaling molecules, has emerged as a powerful regulator of cell fate, proliferation, and function in multicellular organisms. Over the past two decades, the critical role of Wnt signaling in embryonic cartilage and bone development has been well established, and much has been learnt regarding the role of Wnt signaling in chondrogenesis and cartilage development. However, relatively little is known about the role of Wnt signaling in adult articular cartilage and degenerative cartilage tissue. This review will briefly summarize recent advances in Wnt regulation of chondrogenesis and hypertrophic maturation of chondrocytes, and review data concerning the role of Wnt signaling in the maintenance and degeneration of articular chondrocytes and cartilage.

• Journal of Life Science
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• v.19 no.10
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• pp.1346-1351
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• 2009

Recent evidence has shown that many pluripotetic neural crest cells are fate-restricted and that different fate-restricted crest cells emigrate from the neural tube at different times. Jin et al. (2001) identified the expression patterns of Wnts and its antagonists at the time that neural crest cells were being specified and suggested that Wnt signaling was involved in the segregation/differentiation of neural crest cells in the trunk in vitro. In this study, we evaluated the effects of Wnt signaling in avian neural crest lineage segregation. To accomplish this, Wnt signaling was disturbed at the time of neural crest segregation and differentiation by grafting Wnt-3a expressing cells and conducting dominant negative glycogen synthase kinase (dnGSK) electroporation. Stimulation of Wnt signaling induced neural crest lineage segregation and melanoblast specification, and increased the expression levels of genes known to be involved in neural crest development such as cadherin 7 and Slug, which suggests that they are involved in Wnt-induced neural crest lineage differentiation into melanoblasts.

• BMB Reports
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• v.53 no.12
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• pp.628-633
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• 2020

WNT11 is a member of the non-canonical Wnt family and plays a crucial role in tumor progression. However, the regulatory mechanisms underlying WNT11 expression are unclear. Tumor necrosis factor-alpha (TNFα) is a major inflammatory cytokine produced in the tumor microenvironment and contributes to processes associated with tumor progression, such as tumor invasion and metastasis. By using site-directed mutagenesis and introducing a serial deletion in the 5'-regulatory region of WNT11, we observed that TNFα activates the early growth response 1 (EGR1)-binding sequence (EBS) in the proximal region of WNT11 and that the transcription factor EGR1 is necessary for the TNFα-induced transcription of WNT11. EGR1 bound directly to the EBSs within the proximal 5'-regulatory region of WNT11 and ectopic expression of EGR1 stimulated WNT11 promoter activity, whereas the knockdown of EGR1 expression by RNA interference reduced TNFα-induced WNT11 expression in T47D breast cancer cells. We also observed that mitogen-activated protein kinases (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 kinase mediated TNFα-induced transcription of WNT11 via EGR1. Our results suggest that EGR1 directly targets WNT11 in response to TNFα stimulation in breast cancer cells.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.4
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• pp.307-319
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• 2021

Dysregulation of the Wnt pathway causes various diseases including cancer, Parkinson's disease, Alzheimer's disease, schizophrenia, osteoporosis, obesity and chronic kidney diseases. The modulation of dysregulated Wnt pathway is absolutely necessary. In the present study, we evaluated the anti-inflammatory effect and the mechanism of action of Wnt-C59, a Wnt signaling inhibitor, in lipopolysaccharide (LPS)-stimulated epithelial cells and macrophage cells. Wnt-C59 showed a dose-dependent anti-inflammatory effect by suppressing the expression of proinflammatory cytokines including IL6, CCL2, IL1A, IL1B, and TNF in LPS-stimulated cells. The dysregulation of the Wnt/β-catenin pathway in LPS stimulated cells was suppressed by WntC59 treatment. The level of β-catenin, the executor protein of Wnt/β-catenin pathway, was elevated by LPS and suppressed by Wnt-C59. Overexpression of β-catenin rescued the suppressive effect of Wnt-C59 on proinflammatory cytokine expression and nuclear factor-kappa B (NF-κB) activity. We found that the interaction between β-catenin and NF-κB, measured by co-immunoprecipitation assay, was elevated by LPS and suppressed by Wnt-C59 treatment. Both NF-κB activity for its target DNA binding and the reporter activity of NF-κB-responsive promoter showed identical patterns with the interaction between β-catenin and NF-κB. Altogether, our findings suggest that the anti-inflammatory effect of Wnt-C59 is mediated by the reduction of the cellular level of β-catenin and the interaction between β-catenin and NF-κB, which results in the suppressions of the NF-κB activity and proinflammatory cytokine expression.

• Natural Product Sciences
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• v.26 no.2
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• pp.109-117
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• 2020

The canonical Wnt/β-catenin signaling pathways play an important role in the embryonic development, cell proliferation, differentiation, and adhesion. Therefore, the abnormal activation and repression have been associated with uncontrolled homeostasis in human tissues. In particular, the activation of Wnt signaling is highly correlated with a diverse of diseases including cancer. On this regard, a strategy for targeting Wnt/β-catenin signaling has been employed in the discovery and development of antitumor agents. Herein, the evolution of Wnt signaling and the Wnt inhibitors derived from natural products were briefly summarized in the drug discovery of anticancer agents.