• BMB Reports
• /
• v.55 no.6
• /
• pp.299-304
• /
• 2022

Chloride channel-5 (ClC-5), an important branch of the ClC family, is involved in the regulation of the proliferation and cell-fate of a variety of cells, including tumor cells. However, its function in cholangiocarcinoma (CCA) cells remains enigmatic. Here, we discovered that ClC-5 was up-regulated in CCA tissues and CCA cell lines, while ClC-5 silencing inhibited CCA cell proliferation and induced apoptosis. Further mechanism studies revealed that ClC-5 inhibition could inhibit Wnt/β-catenin signaling activity and further activate the mitochondria apoptotic pathway in CCA cells. Furthermore, rescuing Wnt/β-catenin signaling activation eliminated the anti-tumor function of ClC-5 knockdown. Together, our research findings illustrated that ClC-5 inhibition plays an anti-tumor role in CCA cells via inhibiting the activity of the Wnt/β-catenin pathway, which in turn activates the mitochondrial apoptotic pathway.

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

• BMB Reports
• /
• v.49 no.9
• /
• pp.455-456
• /
• 2016

Mutations of APC and KRAS are frequently observed in human colorectal cancers (CRCs) and the Wnt/β-catenin and Ras pathways are consequently activated in a significant proportion of CRC patients. Mutations in these two genes are also known to synergistically induce progression of CRCs. Through a series of studies, we have demonstrated that inhibition of the Wnt/β-catenin signaling pathway negatively regulates Ras stability, therefore, Ras abundance is increased together with β-catenin in both mice and human CRCs harboring adenomatous polyposis coli (APC) mutations. In a recent study, we identified KY1220, a small molecule that simultaneously degrades β-catenin and Ras by inhibition of the Wnt/β-catenin pathway, and obtained its derivative KYA1797K, which has improved activity and solubility. We found that KYA1797K binds the RGS domain of axin and enhances the binding affinity of β-catenin or Ras with the β-catenin destruction complex components, leading to simultaneous destabilization of β-catenin and Ras via GSK3β activation. By using both in vitro and in vivo studies, we showed that KYA1797K suppressed the growth of CRCs harboring APC and KRAS mutations through destabilization of β-catenin and Ras. Therefore, our findings indicate that the simultaneous destabilization of β-catenin and Ras via targeting axin may serve as an effective strategy for inhibition of CRCs.

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

• Bulletin of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.1405-1408
• /
• 2012

• Journal of Life Science
• /
• v.21 no.9
• /
• pp.1301-1309
• /
• 2011

The major function of adipocytes is to store fat in the form of triglycerides. One of the signaling pathways known to affect adipogenesis, i.e. fat formation, is the WNT/${\beta}$-catenin pathway which inhibits the expression and activity of key regulators of adipogenesis. The purpose of this research is to find genes among the WNT/${\beta}$-catenin pathway which regulate adipogenesis by using small interfering (si) RNA and to find the association of single nucleotide polymorphisms (SNPs) of the gene with serum triglyceride levels in the human population. To elucidate the effects of ${\beta}$-catenin siRNA on adipogenesis key factors, PPAR${\gamma}$ and C/EBP${\alpha}$, we performed real-time PCR and western blotting experiments for the analyses of mRNA and protein levels. It was found that the siRNA-mediated knockdown of ${\beta}$-catenin upregulates adipogenesis key factors. However, upstream regulators of the WNT/${\beta}$-catenin pathway, such as DVL2 and LRP6, had no significant effects compared to ${\beta}$-catenin. These results indicate that ${\beta}$-catenin is a candidate gene for human fat accumulation. In general, serum triglyceride level is a good indicator of fat accumulation in humans. According to statistical analyses of the association between serum triglyceride level and SNPs of ${\beta}$-catenin, -10,288 C>T SNP (rs7630377) in the promoter region was significantly associated with serum triglyceride levels (p<0.05) in 290 Korean subjects. On the other hand, serum cholesterol levels were not significantly associated with SNPs of the ${\beta}$-catenin gene. The results of this study showed that ${\beta}$-catenin is associated with fat accumulation both in vitro and in the human population.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.16
• /
• pp.7277-7284
• /
• 2015

Background: The Wnt/${\beta}$-catenin signaling pathway is an important regulator of cellular functions such as proliferation, survival and cell adhesion. Wnt/${\beta}$-catenin signaling is associated with tumor initiation and progression; ${\beta}$-catenin mutations explain only 30% of aberrant signaling found in breast cancer, indicating that other components and/or regulation of the Wnt/${\beta}$-catenin pathway may be involved. Objective: We evaluated AXIN2 rs2240308 and rs151279728 polymorphisms, and expression profiles of ${\beta}$-catenin destruction complex genes in breast cancer patients. Materials and Methods: We collected peripheral blood samples from 102 breast cancer and 102 healthy subjects. The identification of the genetic variation was performed using PCR-RFLPs and DNA sequencing. RT-qPCR was used to determine expression profiles. Results: We found significant association of AXIN2 rs151279728 and rs2240308 polymorphisms with breast cancer risk. Significant increase was observed in AXIN2 level expression in breast cancer patients. Further analyses showed APC, ${\beta}$-catenin, CK1${\alpha}$, GSK3${\beta}$ and PP2A gene expression to be associated to clinic-pathological characteristics. Conclusions: The present study demonstrated, for the first time, that AXIN2 genetic defects and disturbance of ${\beta}$-catenin destruction complex expression may be found in breast cancer patients, providing additional support for roles of Wnt/${\beta}$-catenin pathway dysfunction in breast cancer tumorigenesis. However, the functional consequences of the genetic alterations remain to be determined.

• Molecules and Cells
• /
• v.43 no.2
• /
• pp.188-197
• /
• 2020

Cells are designed to be sensitive to a myriad of external cues so they can fulfil their individual destiny as part of the greater whole. A number of well-characterised signalling pathways dictate the cell's response to the external environment and incoming messages. In healthy, well-ordered homeostatic systems these signals are tightly controlled and kept in balance. However, given their powerful control over cell fate, these pathways, and the transcriptional machinery they orchestrate, are frequently hijacked during the development of neoplastic disease. A prime example is the Wnt signalling pathway that can be modulated by a variety of ligands and inhibitors, ultimately exerting its effects through the β-catenin transcription factor and its downstream target genes. Here we focus on the interplay between the three-member family of RUNX transcription factors with the Wnt pathway and how together they can influence cell behaviour and contribute to cancer development. In a recurring theme with other signalling systems, the RUNX genes and the Wnt pathway appear to operate within a series of feedback loops. RUNX genes are capable of directly and indirectly regulating different elements of the Wnt pathway to either strengthen or inhibit the signal. Equally, β-catenin and its transcriptional co-factors can control RUNX gene expression and together they can collaborate to regulate a large number of third party co-target genes.

• Journal of Ginseng Research
• /
• v.47 no.4
• /
• pp.515-523
• /
• 2023

Background: 20(S)-protopanaxadiol (PPD), one of the main components of ginseng, has anti-inflammatory, anti-estrogenic, and anti-tumor activities. It is known that activated hepatic stellate cells (HSCs) are the primary producers of extracellular matrix (ECM) in the liver, and the Wnt/β-catenin pathway participates in the activation of HSCs. We aimed to explore whether PPD inhibits liver fibrosis is associated with the Wnt/β-catenin pathway inactivation. Methods: The anti-fibrotic roles of PPD were examined both in vitro and in vivo. We also examined the levels of Wnt inhibitory factor 1 (WIF1), DNA methyltransferase 1 (DNMT1) and WIF1 methylation. Results: PPD obviously ameliorated liver fibrosis in carbon tetrachloride (CCl₄)-treated mice and reduced collagen deposition. PPD also suppressed the activation and proliferation of primary HSCs. Notably, PPD inhibited the Wnt/β-catenin pathway, reduced TCF activity, and increased P-β-catenin and GSK-3β levels. Interestingly, WIF1 was found to mediate the inactivation of the Wnt/β-catenin pathway in PPD-treated HSCs. WIF1 silencing suppressed the inhibitory effects of PPD on HSC activation and also restored α-SMA and type I collagen levels. The downregulation of WIF1 expression was associated with the methylation of its promoter. PPD induced WIF1 demethylation and restored WIF1 expression. Further experiments confirmed that DNMT1 overexpression blocked the effects of PPD on WIF1 expression and demethylation and enhanced HSC activation. Conclusion: PPD up-regulates WIF1 levels and impairs Wnt/β-catenin pathway activation via the downregulation of DNMT1-mediated WIF1 methylation, leading to HSC inactivation. Therefore, PPD may be a promising therapeutic drug for patients with liver fibrosis.

• Journal of Biomedical Engineering Research
• /
• v.41 no.6
• /
• pp.235-246
• /
• 2020

This study aimed to evaluate the inhibitory effect of micro-current stimulation(MCS) on adipogenesis regarding with Wnt/β-catenin pathway using the ob/ob mouse and 3T3-L1 cell line. 6-week old ob/ob male mice were equally assigned to four groups: obese group(ob), obese with MCS groups(50 μA, 200 μA, and 400 μA). 6-week old C57BL/6J male mice were assigned to the control group(CON). We analyzed abdominal adipose tissue volume by using in vivo micro-CT and measured the body weight, feed intake, liver weight and triglycerides in serum. All the MCS groups showed that significantly reduced body weight and triglycerides in serum. In the case of liver weight and abdominal adipose tissue volume, the inhibitory effect of adipogenesis was shown in the 200 μA and 400 μA groups. To elucidate the anti-obesity effect of MCS, β-catenin, C/EBPα and FAS protein expressions were analyzed by western blotting. β-catenin expression was upregulated, C/EBPα and FAS expression were down-regulated in the relatively high-intensity groups(200 μA and 400 μA). Thus, the 200 μA and 400 μA for the intensity of MCS were chosen for cell experiments. In the 3T3-L1 cell line, Wnt/β-catenin pathway including Wnt10b, Wnt3a, β-catenin and Cyclin D1 was activated in all MCS groups. Accordingly, the expression level of C/EBPα was decreased during the differentiation and lipid droplet was significantly reduced in Oil red O staining results. These results suggest that the Wnt/β-catenin signaling might be activated by MCS with current intensities between 200-400 μA and it may lead to anti-obesity effects.