• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.21-30
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• 2024

The challenging clinical outcomes associated with advanced cervical cancer underscore the need for a novel therapeutic approach. Monensin, a polyether antibiotic, has recently emerged as a promising candidate with anti-cancer properties. In line with these ongoing efforts, our study presents compelling evidence of monensin's potent efficacy in cervical cancer. Monensin exerts a pronounced inhibitory impact on proliferation and anchorage-independent growth. Additionally, monensin significantly inhibited cervical cancer growth in vivo without causing any discernible toxicity in mice. Mechanism studies show that monensin's anti-cervical cancer activity can be attributed to its capacity to inhibit the Wnt/β-catenin pathway, rather than inducing oxidative stress. Monensin effectively reduces both the levels and activity of β-catenin, and we identify Akt, rather than CK1, as the key player involved in monensin-mediated Wnt/β-catenin inhibition. Rescue studies using Wnt activator and β-catenin-overexpressing cells confirmed that β-catenin inhibition is the mechanism of monensin's action. As expected, cervical cancer cells exhibiting heightened Wnt/β-catenin activity display increased sensitivity to monensin treatment. In conclusion, our findings provide pre-clinical evidence that supports further exploration of monensin's potential for repurposing in cervical cancer therapy, particularly for patients exhibiting aberrant Wnt/β-catenin activation.

• Biomolecules & Therapeutics
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• v.24 no.6
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• pp.572-580
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• 2016

3-Deoxysappanchalcone (3-DSC) has been reported to possess anti-allergic, antiviral, anti-inflammatory and antioxidant activities. In the present study, we investigated the effects of 3-DSC on the proliferation of human hair follicle dermal papilla cells (HDPCs) and mouse hair growth in vivo. A real-time cell analyzer system, luciferase assay, Western blot and real-time polymerase chain reaction (PCR) were employed to measure the biochemical changes occurring in HDPCs in response to 3-DSC treatment. The effect of 3-DSC on hair growth in C57BL/6 mice was also examined. 3-DSC promoted the proliferation of HDPCs, similar to Tofacitinib, an inhibitor of janus-activated kinase (JAK). 3-DSC promoted phosphorylation of ${\beta}$-catenin and transcriptional activation of the T-cell factor. In addition, 3-DSC potentiated interleukin-6 (IL-6)-induced phosphorylation and subsequent transactivation of signal transducer and activator of transcription-3 (STAT3), thereby increasing the expression of cyclin-dependent kinase-4 (Cdk4), fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). On the contrary, 3-DSC attenuated STAT6 mRNA expression and IL4-induced STAT6 phosphorylation in HDPCs. Finally, we observed that topical application of 3-DSC promoted the anagen phase of hair growth in C57BL/6 mice. 3-DSC stimulates hair growth possibly by inducing proliferation of follicular dermal papilla cells via modulation of $WNT/{\beta}$-catenin and STAT signaling.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.48-49
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• 2001

The carcinogens 2-amino-3-methylimidazo［4, 5-f］quinoline (IQ) and 1, 2-dimethylhydrazine (DMH) induce colon tumors in the Fisher 344 rat that contain mutations in Ctnnbl, the gene for b-catenin, but the pattern of mutation differs from that found in human colon cancers. In both species, mutations affect the glycogen synthase kinase 3$\beta$ (GSK-3$\beta$) consensus region of $\beta$-catenin, but whereas they directly substitute critical Ser/Thr phosphorylation sites in human colon cancers, the majority of mutations cluster around Ser$_{33}$ in the rat tumors.(omitted)d)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10b
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• pp.5-6
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• 2001

The carcinogens 2-arnioo-3-methylimidazo［4,5-f］quinoline (IQ) and 1,2-dimethylhydrazine (DMH) induce colon tumors in the Fisher 344 rat that contain mutations in Ctnnb1, the gene for b-catenin, but the pattern of mutation differs from that found in human colon cancers. in both species, mutations affect the glycogen synthase kinase 3$\beta$ (GSK-3$\beta$) consensus region of $\beta$-catenin, but whereas they directly substitute critical Ser/Thr phosphorylation sites in human colon cancers, the majority of mutations cluster around Ser$^{33}$ in the rat tumors.(omitted)

• Journal of Microbiology and Biotechnology
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• v.33 no.9
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• pp.1206-1212
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• 2023

The Wnt/β-catenin pathway plays essential roles in regulating various cellular behaviors, including proliferation, survival, and differentiation [1-3]. The intracellular β-catenin level, which is regulated by a proteasomal degradation pathway, is critical to Wnt/β-catenin pathway control [4]. Normally, casein kinase 1 (CK1) and glycogen synthase kinase-3β (GSK-3β), which form a complex with the scaffolding protein Axin and the tumor suppressor protein adenomatous polyposis coli (APC), phosphorylate β-catenin at Ser45, Thr41, Ser37, and Ser33 [5, 6]. Phosphorylated β-catenin is ubiquitinated by the β-transducin repeat-containing protein (β-TrCP), an F-box E3 ubiquitin ligase complex, and ubiquitinated β-catenin is degraded via a proteasome pathway [7, 8]. Colorectal cancer is a significant cause of cancer-related deaths worldwide. Abnormal up-regulation of the Wnt/β-catenin pathway is a major pathological event in intestinal epithelial cells during human colorectal cancer oncogenesis [9]. Genetic mutations in the APC gene are observed in familial adenomatous polyposis coli (FAP) and sporadic colorectal cancers [10]. In addition, mutations in the N-terminal phosphorylation motif of the β-catenin gene were found in patients with colorectal cancer [11]. These mutations cause β-catenin to accumulate in the nucleus, where it forms complexes with transcription factors of the T-cell factor/lymphocyte enhancer factor (TCF/LEF) family to stimulate the expression of β-catenin responsive genes, such as c-Myc and cyclin D1, which leads to colorectal tumorigenesis [12-14]. Therefore, downregulating β-catenin response transcription (CRT) is a potential strategy for preventing and treating colorectal cancer. Plant cytokinins are N⁶-substituted purine derivatives; they promote cell division in plants and regulate developmental pathways. Natural cytokinins are classified as isoprenoid (isopentenyladenine, zeatin, and dihydrozeatin), aromatic (benzyladenine, topolin, and methoxytopolin), or furfural (kinetin and kinetin riboside), depending on their structure [15, 16]. Kinetin riboside was identified in coconut water and is a naturally produced cytokinin that induces apoptosis and exhibits antiproliferative activity in several human cancer cell lines [17]. However, little attention has been paid to kinetin riboside's mode of action. In this study, we show that kinetin riboside exerts its cytotoxic activity against colon cancer cells by suppressing the Wnt/β-catenin pathway and promoting intracellular β-catenin degradation.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1298-1302
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• 2007

A hallmark of cancers is 'leaky' tight junctions (Tjs). TJs mediated paracellular permeability is elevated and TJs maintained cell polarity is frequently lost. Concomitantly, TJs-associated proteins including members of the claudin family of proteins are dysregulated. Recent findings indicate that these TJs changes can contribute to cancer progression. In this study, we examined the effects of ${\beta}-lapachone$, a quinone compound obtained from the bark of the lapacho tree (Tabebuia avellanedae), on the Tjs-associated regulators in human hepatocarcinoma cell lines, HepG2 and Hep3B. ${\beta}-lapachone$ treatment downregulated the levels of insulin-like growth factor 1 receptor (IGF-lR) proteins in both HepG2 and Hep3B cells. But the levels of claudin-3 and -4 proteins were increased in ${\beta}-lapachone$-treated HepG2 and Hep3B cells. And also the zonnula occludens-l (la-I) and p-catenin protein levels by ${\beta}-lapachone$ were increased in a time-dependent manner. However, claudin-3 and -4 mRNA levels were uninhibited by ${\beta}-lapachone$ in HepG2 and Hep3B. The present results suggest that the upregulation of claudin-3 and -4 protein levels by ${\beta}-lapachone$ occurs by a post-transcriptional mechanism and points to a novel mechanism by ${\beta}-lapachone$.

• BMB Reports
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• v.53 no.8
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• pp.425-430
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• 2020

Tumor necrosis factor-inducible gene 6 protein (TSG-6) is a cytokine secreted by mesenchymal stem cells (MSCs) and regulates MSC stemness. We previously reported that TSG-6 changes primary human hepatic stellate cells (pHSCs) into stem-like cells by activating yes-associated protein-1 (YAP-1). However, the molecular mechanism behind the reprogramming action of TSG-6 in pHSCs remains unknown. Cluster of differentiation 44 (CD44) is a transmembrane protein that has multiple functions depending on the ligand it is binding, and it is involved in various signaling pathways, including the Wnt/β-catenin pathway. Given that β-catenin influences stemness and acts downstream of CD44, we hypothesized that TSG-6 interacts with the CD44 receptor and stimulates β-catenin to activate YAP-1 during TSG-6-mediated transdifferentiation of HSCs. Immunoprecipitation assays showed the interaction of TSG-6 with CD44, and immunofluorescence staining analyses revealed the colocalization of TSG-6 and CD44 at the plasma membrane of TSG-6-treated pHSCs. In addition, TSG-6 treatment upregulated the inactive form of phosphorylated glycogen synthase kinase (GSK)-3β, which is a negative regulator of β-catenin, and promoted nuclear accumulation of active/nonphosphorylated β-catenin, eventually leading to the activation of YAP-1. However, CD44 suppression in pHSCs following CD44 siRNA treatment blocked the activation of β-catenin and YAP-1, which inhibited the transition of TSG-6-treated HSCs into stem-like cells. Therefore, these findings demonstrate that TSG-6 interacts with CD44 and activates β-catenin and YAP-1 during the conversion of TSG-6-treated pHSCs into stem-like cells, suggesting that this novel pathway is an effective therapeutic target for controlling liver disease.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.465-472
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• 2020

Colorectal cancer (CRC) is one of the most malignant type of cancers and its incidence is steadily increasing, due to life style factors that include western diet. Abnormal activation of canonical Wnt/β-catenin signaling pathway plays an important role in colorectal carcinogenesis. Therefore, targeting Wnt/β-catenin signaling has been considered a crucial strategy in the discovery of small molecules for CRC. In the present study, we found that Nodosin, an ent-kaurene diterpenoid isolated from Isodon serra, effectively inhibits the proliferation of human colon cancer HCT116 cells. Mechanistically, Nodosin effectively inhibited the overactivated transcriptional activity of β-catenin/T-cell factor (TCF) determined by Wnt/β-catenin reporter gene assay in HEK293 and HCT116 cells. The expression of Wnt/β-catenin target genes such as Axin2, cyclin D1, and survivin were also suppressed by Nodosin in HCT116 cells. Further study revealed that a longer exposure of Nodosin induced the G₂/M phase cell cycle arrest and subsequently apoptosis in HCT116 cells. These findings suggest that the anti-proliferative activity of Nodosin in colorectal cancer cells might in part be associated with the regulation of Wnt/β-catenin signaling pathway.

• BMB Reports
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• v.55 no.5
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• pp.244-249
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• 2022

Characterized by abnormal proliferation and migration of vascular smooth muscle cells (VSMCs), neointima hyperplasia is a hallmark of vascular restenosis after percutaneous vascular interventions. Vaccinia-related kinase 1 (VRK1) is a stress adaption-associated ser/thr protein kinase that can induce the proliferation of various types of cells. However, the role of VRK1 in the proliferation and migration of VSMCs and neointima hyperplasia after vascular injury remains unknown. We observed increased expression of VRK1 in VSMCs subjected to platelet-derived growth factor (PDGF)-BB by western blotting. Silencing VRK1 by shVrk1 reduced the number of Ki-67-positive VSMCs and attenuated the migration of VSMCs. Mechanistically, we found that relative expression levels of β-catenin and effectors of mTOR complex 1 (mTORC1) such as phospho (p)-mammalian target of rapamycin (mTOR), p-S6, and p-4EBP1 were decreased after silencing VRK1. Restoration of β-catenin expression by SKL2001 and re-activation of mTORC1 by Tuberous sclerosis 1 siRNA (siTsc1) both abolished shVrk1-mediated inhibitory effect on VSMC proliferation and migration. siTsc1 also rescued the reduced expression of β-catenin caused by VRK1 inhibition. Furthermore, mTORC1 re-activation failed to recover the attenuated proliferation and migration of VSMC resulting from shVrk1 after silencing β-catenin. We also found that the vascular expression of VRK1 was increased after injury. VRK1 inactivation in vivo inhibited vascular injury-induced neointima hyperplasia in a β-catenin-dependent manner. These results demonstrate that inhibition of VRK1 can suppress the proliferation and migration of VSMC and neointima hyperplasia after vascular injury via mTORC1/β-catenin pathway.

• BMB Reports
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• v.55 no.11
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• pp.559-564
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• 2022

Diabetes mellitus is one of the most prevalent diseases in modern society. Many complicationssuch as hepatic cirrhosis, neuropathy, cardiac infarction, and so on are associated with diabetes. Although a relationship between diabetes and hair loss has been recently reported, the treatment of diabetic hair loss by Wnt/β-catenin activators has not been achieved yet. In this study, we found that the depilation-induced anagen phase was delayed in both db/db mice and high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic mice. In diabetic mice, both hair regrowth and wound-induced hair follicle neogenesis (WIHN) were reduced because of suppression of Wnt/β-catenin signaling and decreased proliferation of hair follicle cells. We identified that KY19382, a small molecule that activates Wnt/β-catenin signaling, restored the capabilities of regrowth and WIHN in diabetic mice. The Wnt/β-catenin signaling activator also increased the length of the human hair follicle which was decreased under high glucose culture conditions. Overall, the diabetic condition reduced both hair regrowth and regeneration with suppression of the Wnt/β-catenin signaling pathway. Consequently, the usage of Wnt/β-catenin signaling activators could be a potential strategy to treat diabetes-induced alopecia patients.