Cdc42 controls progenitor cell differentiation and beta-catenin turnover in skin

DEFF Research Database (Denmark)

Wu, Xunwei; Quondamatteo, Fabio; Lefever, Tine

2006-01-01

for differentiation of skin progenitor cells into HF lineage and that it regulates the turnover of beta-catenin. In the absence of Cdc42, degradation of beta-catenin was increased corresponding to a decreased phosphorylation of GSK3beta at Ser 9 and an increased phosphorylation of axin, which is known to be required...... for binding of beta-catenin to the degradation machinery. Cdc42-mediated regulation of beta-catenin turnover was completely dependent on PKCzeta, which associated with Cdc42, Par6, and Par3. These data suggest that Cdc42 regulation of beta-catenin turnover is important for terminal differentiation of HF...

Gene silencing of beta-catenin in melanoma cells retards their growth but promotes the formation of pulmonary metastasis in mice.

Science.gov (United States)

Takahashi, Yuki; Nishikawa, Makiya; Suehara, Tetsuya; Takiguchi, Naomi; Takakura, Yoshinobu

2008-11-15

Altered expression of beta-catenin, a key component of the Wnt signaling pathway, is involved in a variety of cancers because increased levels of beta-catenin protein are frequently associated with enhanced cellular proliferation. Although our previous study demonstrated that gene silencing of beta-catenin in melanoma B16-BL6 cells by plasmid DNA (pDNA) expressing short-hairpin RNA targeting the gene (pshbeta-catenin) markedly suppressed their growth in vivo, gene silencing of beta-catenin could promote tumor metastasis by the rearranging cell adhesion complex. In this study, we investigated how silencing of beta-catenin affects metastatic aspects of melanoma cells. Transfection of B16-BL6 cells with pshbeta-catenin significantly reduced the amount of cadherin protein, a cell adhesion molecule binding to beta-catenin, with little change in its mRNA level. Cadherin-derived fragments were detected in culture media of B16-BL6 cells transfected with pshbeta-catenin, suggesting that cadherin is shed from the cell surface when the expression of beta-catenin is reduced. The mobility of B16-BL6 cells transfected with pshbeta-catenin was greater than that of cells transfected with any of the control pDNAs. B16-BL6 cells stably transfected with pshbeta-catenin (B16/pshbeta-catenin) formed less or an equal number of tumor nodules in the lung than cells stably transfected with other plasmids when injected into mice via the tail vein. However, when subcutaneously inoculated, B16/pshbeta-catenin cells formed more nodules in the lung than the other stably transfected cells. These results raise concerns about the gene silencing of beta-catenin for inhibiting tumor growth, because it promotes tumor metastasis by reducing the amount of cadherin in tumor cells. (c) 2008 Wiley-Liss, Inc.

Inhibition of endocytosis blocks Wnt signalling to beta-catenin by promoting dishevelled degradation

Czech Academy of Sciences Publication Activity Database

Bryja, Vítězslav; Čajánek, L.; Grahn, A.; Schulte, G.

2007-01-01

Roč. 190, č. 1 (2007), s. 53-596 ISSN 0001-6772 Institutional research plan: CEZ:AV0Z50040507 Keywords : beta-catenin * clathrin-mediated endocytosis * desensitization Subject RIV: BO - Biophysics Impact factor: 2.554, year: 2007

MicroRNA-320a suppresses human colon cancer cell proliferation by directly targeting {beta}-catenin

Energy Technology Data Exchange (ETDEWEB)

Sun, Jian-Yong [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Huang, Yi [Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, 710032 Xi' an (China); Li, Ji-Peng [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Zhang, Xiang; Wang, Lei [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Meng, Yan-Ling [Department of Immunology, Fourth Military Medical University, 710032 Xi' an (China); Yan, Bo [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Bian, Yong-Qian [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Zhao, Jing [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Wang, Wei-Zhong, E-mail: weichang@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); and others

2012-04-20

Highlights: Black-Right-Pointing-Pointer miR-320a is downregulated in human colorectal carcinoma. Black-Right-Pointing-Pointer Overexpression of miR-320a inhibits colon cancer cell proliferation. Black-Right-Pointing-Pointer {beta}-Catenin is a direct target of miR-320a in colon cancer cells. Black-Right-Pointing-Pointer miR-320a expression inversely correlates with mRNA expression of {beta}-catenin's target genes in human colon carcinoma. -- Abstract: Recent profile studies of microRNA (miRNA) expression have documented a deregulation of miRNA (miR-320a) in human colorectal carcinoma. However, its expression pattern and underlying mechanisms in the development and progression of colorectal carcinoma has not been elucidated clearly. Here, we performed real-time PCR to examine the expression levels of miR-320a in colon cancer cell lines and tumor tissues. And then, we investigated its biological functions in colon cancer cells by a gain of functional strategy. Further more, by the combinational approaches of bioinformatics and experimental validation, we confirmed target associations of miR-320a in colorectal carcinoma. Our results showed that miR-320a was frequently downregulated in cancer cell lines and colon cancer tissues. And we demonstrated that miR-320a restoration inhibited colon cancer cell proliferation and {beta}-catenin, a functionally oncogenic molecule was a direct target gene of miR-320a. Finally, the data of real-time PCR showed the reciprocal relationship between miR-320a and {beta}-catenin's downstream genes in colon cancer tissues. These findings indicate that miR-320a suppresses the growth of colon cancer cells by directly targeting {beta}-catenin, suggesting its application in prognosis prediction and cancer treatment.

Human APC sequesters beta-catenin even in the absence of GSK-3beta in a Drosophila model.

Science.gov (United States)

Rao, P R; Makhijani, K; Shashidhara, L S

2008-04-10

There have been conflicting reports on the requirement of GSK-3beta-mediated phosphorylation of the tumor suppressor adenomatous polyposis coli (APC) vis-à-vis its ability to bind and degrade beta-catenin. Using a unique combination of loss of function for Shaggy/GSK-3beta and a gain of function for human APC in Drosophila, we show that misexpressed human APC (hAPC) can still sequester Armadillo/beta-catenin. In addition, human APC could suppress gain of Wnt/Wingless phenotypes associated with loss of Shaggy/GSK-3beta activity, suggesting that sequestered Armadillo/beta-catenin is non-functional. Based on these studies, we propose that binding per se of beta-catenin by APC does not require phosphorylation by GSK-3beta.

E-cadherin and beta-catenin are down-regulated in prostatic bone metastases.

Science.gov (United States)

Bryden, A A G; Hoyland, J A; Freemont, A J; Clarke, N W; Schembri Wismayer, D; George, N J R

2002-03-01

To determine the E-cadherin and beta-catenin expression phenotype in untreated primary prostate cancer and corresponding bone metastases. Paired bone metastasis and primary prostate specimens were obtained from 14 men with untreated metastatic prostate carcinoma. The tumours were histologically graded by an independent pathologist. Expression of mRNA for E-cadherin and beta-catenin was detected within the tumour cells using in-situ hybridization with a 35S-labelled cDNA probe. The expression of E-cadherin and beta-catenin were graded as uniform, heterogeneous or negative. The mRNA for E-cadherin was expressed in 13 of 14 primary carcinomas and 11 bone metastases; beta-catenin was expressed by 13 and nine, respectively. Of the primary tumours, nine expressed E-cadherin and beta-catenin uniformly; in contrast, all metastases had down-regulated E-cadherin and/or beta-catenin. The down-regulation of E-cadherin and beta-catenin are a feature of the metastatic phenotype, which may be a significant factor in the genesis of bone metastases. However, this does not appear to be reflected in the expression of these molecules in the primary tumours.

Concurrent Transient Activation of Wnt/{beta}-Catenin Pathway Prevents Radiation Damage to Salivary Glands

Energy Technology Data Exchange (ETDEWEB)

Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States); Boyer, Arthur [Department of Radiology, Scott and White Hospital, Temple, Texas (United States); Liu, Fei, E-mail: fliu@medicine.tamhsc.edu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States)

2012-05-01

Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/{beta}-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/{beta}-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/{beta}-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/{beta}-catenin pathway could prevent radiation-induced salivary gland dysfunction.

Plasma membrane recruitment of dephosphorylated beta-catenin upon activation of the Wnt pathway

NARCIS (Netherlands)

Hendriksen, Jolita; Jansen, Marnix; Brown, Carolyn M.; van der Velde, Hella; van Ham, Marco; Galjart, Niels; Offerhaus, G. Johan; Fagotto, Francois; Fornerod, Maarten

2008-01-01

The standard model of Wnt signaling specifies that after receipt of a Wnt ligand at the membranous receptor complex, downstream mediators inhibit a cytoplasmic destruction complex, allowing beta-catenin to accumulate in the cytosol and nucleus and co-activate Wnt target genes. Unexpectedly, shortly

Periplocin from Cortex periplocae inhibits cell growth and down-regulates survivin and c-myc expression in colon cancer in vitro and in vivo via beta-catenin/TCF signaling.

Science.gov (United States)

Zhao, Lianmei; Shan, Baoen; Du, Yanyan; Wang, Mingxia; Liu, Lihua; Ren, Feng-Zhi

2010-08-01

Cancer of the colon and rectum is the third most commonly diagnosed cancer and accounts for approximately 10% of all cancer-related deaths. Although surgical resection or radiotherapy are potentially curative for localized disease, advanced colon cancer is currently associated with poor prognosis. Therefore, the development of a new and effective chemotherapeutic agent is required to target critical pathways to induce responsiveness of colon cancer cells to death signals. Dysregulation of the beta-catenin/TCF pathway plays a central role in early activities of colorectal carcinogenesis. In this study, human colon cancer SW480 cells were used to investigate the effect of CPP (periplocin from Cortex periplocae) on the modulation of the beta-catenin/TCF signaling pathway. Our research results showed that CPP caused a dose- and time-dependent inhibition of cell growth as assessed by MTT assay and an induction in apoptosis as measured by flow cytometry and transmission electron microscopy. Furthermore, the CPP- treated cells were characterized by a decreased expression of beta-catenin protein in the total cell lysates and cytosolic and nuclear extracts. This expression alleviates the binding activity of T-cell factor (Tcf) complexes to its specific DNA-binding sites. Thus, the protein expression of the downstream elements survivin and c-myc was down-regulated. To determine the precise inhibitory mechanisms involved, further in-depth in vivo studies of CPP are warranted. In conclusion, our data suggest that CPP wields a multi-prong strategy to target the beta-catenin/Tcf signaling pathway, leading to the induction of apoptosis and inhibition of growth of colon cancer cells in vitro and in vivo. Therefore, CPP may become a potential agent against colon cancer.

Parkin protects dopaminergic neurons from excessive Wnt/{beta}-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Rawal, Nina [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden); Corti, Olga [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Sacchetti, Paola [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden); Ardilla-Osorio, Hector [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Sehat, Bita [Cancer Center Karolinska, Karolinska Institute, S-17177 Stockholm (Sweden); Brice, Alexis [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Department of Genetics and Cytogenetics, AP-HP, Groupe Hospitalier Pitie-Salpetriere, Paris (France); Arenas, Ernest, E-mail: Ernest.Arenas@ki.se [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden)

2009-10-23

Parkinson's disease (PD) is caused by degeneration of the dopaminergic (DA) neurons of the substantia nigra but the molecular mechanisms underlying the degenerative process remain elusive. Several reports suggest that cell cycle deregulation in post-mitotic neurons could lead to neuronal cell death. We now show that Parkin, an E3 ubiquitin ligase linked to familial PD, regulates {beta}-catenin protein levels in vivo. Stabilization of {beta}-catenin in differentiated primary ventral midbrain neurons results in increased levels of cyclin E and proliferation, followed by increased levels of cleaved PARP and loss of DA neurons. Wnt3a signaling also causes death of post-mitotic DA neurons in parkin null animals, suggesting that both increased stabilization and decreased degradation of {beta}-catenin results in DA cell death. These findings demonstrate a novel regulation of Wnt signaling by Parkin and suggest that Parkin protects DA neurons against excessive Wnt signaling and {beta}-catenin-induced cell death.

Functions of Beta- and Gamma-Catenins in Prostate Cancer

National Research Council Canada - National Science Library

Reed, John

2001-01-01

.... We recently discovered that the protein Siah-1 interacts with the APC/catenin complex, and regulates the ubiquitin-dependent turnover of beta-catenin through a novel previously unidentified mechanism...

Thermodynamics in Gliomas: Interactions between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma

Directory of Open Access Journals (Sweden)

Alexandre Vallée

2017-05-01

Full Text Available Gliomas cells are the site of numerous metabolic and thermodynamics abnormalities with an increasing entropy rate which is characteristic of irreversible processes driven by changes in Gibbs energy, heat production, intracellular acidity, membrane potential gradient, and ionic conductance. We focus our review on the opposing interactions observed in glioma between the canonical WNT/beta-catenin pathway and PPAR gamma and their metabolic and thermodynamic implications. In gliomas, WNT/beta-catenin pathway is upregulated while PPAR gamma is downregulated. Upregulation of WNT/beta-catenin signaling induces changes in key metabolic enzyme that modify their thermodynamics behavior. This leads to activation pyruvate dehydrogenase kinase 1(PDK-1 and monocarboxylate lactate transporter 1 (MCT-1. Consequently, phosphorylation of PDK-1 inhibits pyruvate dehydrogenase complex (PDH. Thus, a large part of pyruvate cannot be converted into acetyl-CoA in mitochondria and in TCA (tricarboxylic acid cycle. This leads to aerobic glycolysis despite the availability of oxygen, named Warburg effect. Cytoplasmic pyruvate is, in major part, converted into lactate. The WNT/beta-catenin pathway induces also the transcription of genes involved in cell proliferation, cell invasiveness, nucleotide synthesis, tumor growth, and angiogenesis, such as c-Myc, cyclin D1, PDK. In addition, in gliomas cells, PPAR gamma is downregulated, leading to a decrease in insulin sensitivity and an increase in neuroinflammation. Moreover, PPAR gamma contributes to regulate some key circadian genes. Abnormalities in the regulation of circadian rhythms and dysregulation in circadian clock genes are observed in gliomas. Circadian rhythms are dissipative structures, which play a key role in far-from-equilibrium thermodynamics through their interactions with WNT/beta-catenin pathway and PPAR gamma. In gliomas, metabolism, thermodynamics, and circadian rhythms are tightly interrelated.

beta-catenin tyrosine 654 phosphorylation increases Wnt signalling and intestinal tumorigenesis

NARCIS (Netherlands)

van Veelen, Wendy; Le, Ngoc H.; Helvensteijn, Werner; Blonden, Lau; Theeuwes, Myrte; Bakker, Elvira R. M.; Franken, Patrick F.; van Gurp, Leon; Meijlink, Frits; van der Valk, Martin A.; Kuipers, Ernst J.; Fodde, Riccardo; Smits, Ron

Objective Deregulation of the Wnt signalling pathway by mutations in the Apc or beta-catenin genes underlies colorectal carcinogenesis. As a result, beta-catenin stabilises, translocates to the nucleus, and activates gene transcription. Intestinal tumours show a heterogeneous pattern of nuclear

beta-catenin tyrosine 654 phosphorylation increases Wnt signalling and intestinal tumorigenesis

NARCIS (Netherlands)

van Veelen, W.; Le, N.H.; Helvensteijn, W.; Blonden, L.; Theeuwes, M.; Bakker, E.R.; Franken, P.F.; van Gurp, L.; Meijlink, F.; van der Valk, M.A.; Kuipers, E.J.; Fodde, R.; Smits, R.E.H.M.

2011-01-01

Objective Deregulation of the Wnt signalling pathway by mutations in the Apc or beta-catenin genes underlies colorectal carcinogenesis. As a result, beta-catenin stabilises, translocates to the nucleus, and activates gene transcription. Intestinal tumours show a heterogeneous pattern of nuclear

Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma.

Directory of Open Access Journals (Sweden)

Myoung Sook Kim

2010-02-01

Full Text Available Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH in a significant proportion of primary esophageal squamous cell carcinoma (ESCC samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation. Loss of NEFH caused up-regulation of pyruvate kinase-M2 type and down-regulation of pyruvate dehydrogenase, via activation of the Akt/beta-catenin pathway, resulting in enhanced aerobic glycolysis and mitochondrial dysfunction. The acceleration of glycolysis and mitochondrial dysfunction in NEFH-knockdown cells was suppressed in the absence of beta-catenin expression, and was decreased by the treatment of 2-Deoxyglucose, a glycolytic inhibitor, or API-2, an Akt inhibitor. Loss of NEFH activates the Akt/beta-catenin pathway and increases glycolysis and mitochondrial dysfunction. Cancer cells with methylated NEFH can be targeted for destruction with specific inhibitors of deregulated downstream pathways.

[Effect of ginseng polysaccharide-induced wnt/beta-catenin signal transduction pathway on apoptosis of human nasopharyngeal cancer cells CNE-2].

Science.gov (United States)

Fan, Jia-Ming; Liu, Ze-Hong; Li, Jing; Wang, Ya-Ping; Yang, Lv-Yuan; Huang, Jiang-Ju

2013-10-01

To observe the effect of ginseng polysaccharide (GPS) on the proliferation and apoptosis of human nasopharyngeal cancer cells CNE-2, and discuss the possible mechanism. The effect of GPS on the growth of CNE-2 cells was observed by CCK8 assay. CNE-2 cells in the logarithmic phase were collected and processed respectively with different concentrations (0, 0. 1, 0. 2, 0. 3. 0. 4 g L-1) of GPS for 48 h. The flow cytometry was used to detect its induction effect on CNE-2 cell apoptosis. Hoechst-33258 cell staining and electron microscope were used to observe the morphological changes of cells. The beta-catenin mRNA expression was detected by Real-time PCR. The protein localizations and expressions of beta-catenin and TCF4 were tested by the immunofluorescence staining. The expressions of beta-catenin, Bcl-2 and Bax proteins were detected by Western blot. CCK8 assay results showed that GPS could remarkably inhibit the proliferation of CNE-2 cells, with dose-time dependence. IC50 of cells induced with GPS for 48 h was 0. 39 g L-1. After being processed with GPS with concentrations of 0.1, 0. 2, 0. 3, 0. 4 g L-1 for 48 h, the cell apoptosis rates of human nasopharyngeal cancer cells CNE-2 were (5. 69 +/- 0. 29)% , (10. 3 +/- 0. 63)% , (15. 4 +/- 0. 74 ) % and (35. 7 +/- 1. 86)% , respectively. Significant difference was observed compared with the control group (2. 08 +/- 0. 11) % (P GPS with the concentration of 0. 4 g L -1 for 48 h. The results of Real-time PCR showed a significant reduction in beta-catenin mRNA expression. The results of laser confocal microscopy revealed notable decrease of beta-catenin and TCF4 expression in nucleus and transfer from nucleus to cell membranes in beta-catenin expression areas after being processed with GPS for 48 h. Western blot showed significant decrease in the expressions of beta-catenin and anti-apoptosis protein Bcl-2, with an increasing expression in apoptosis-promoting protein Bax (P GPS could significantly inhibit the

Cytotoxicity and activation of the Wnt/beta-catenin pathway in mouse embryonic stem cells treated with four GSK3 inhibitors.

Science.gov (United States)

Naujok, Ortwin; Lentes, Jana; Diekmann, Ulf; Davenport, Claudia; Lenzen, Sigurd

2014-04-29

Small membrane-permeable molecules are now widely used during maintenance and differentiation of embryonic stem cells of different species. In particular the glycogen synthase kinase 3 (GSK3) is an interesting target, since its chemical inhibition activates the Wnt/beta-catenin pathway. In the present comparative study four GSK3 inhibitors were characterized. Cytotoxicity and potential to activate the Wnt/beta-catenin pathway were tested using the commonly used GSK3 inhibitors BIO, SB-216763, CHIR-99021, and CHIR-98014. Wnt/beta-catenin-dependent target genes were measured by quantitative PCR to confirm the Wnt-reporter assay and finally EC50-values were calculated. CHIR-99021 and SB-216763 had the lowest toxicities in mouse embryonic stem cells and CHIR-98014 and BIO the highest toxicities. Only CHIR-99021 and CHIR-98014 lead to a strong induction of the Wnt/beta-catenin pathway, whereas BIO and SB-216763 showed a minor or no increase in activation of the Wnt/beta-catenin pathway over the natural ligand Wnt3a. The data from the Wnt-reporter assay were confirmed by gene expression analysis of the TCF/LEF regulated gene T. Out of the four tested GSK3 inhibitors, only CHIR-99021 and CHIR-98014 proved to be potent pharmacological activators of the Wnt/beta-catenin signaling pathway. But only in the case of CHIR-99021 high potency was combined with very low toxicity.

Regulation of AR and (beta)-Catenin Signaling by Pin 1 in Prostate Cancer

National Research Council Canada - National Science Library

Chen, Shaoyong

2006-01-01

.... The mechanisms include that Pin1 can enhance beta-catenin nuclear localization, TCF/beta-catenin dependent Topflash activity, and c-Myc and Cyclin D1 expression, and disrupt AR-mediated suppression...

Apc bridges Wnt/{beta}-catenin and BMP signaling during osteoblast differentiation of KS483 cells

Energy Technology Data Exchange (ETDEWEB)

Miclea, Razvan L., E-mail: R.L.Miclea@lumc.nl [Department of Pediatrics, Leiden University Medical Centre (LUMC), Leiden (Netherlands); Horst, Geertje van der, E-mail: G.van_der_Horst@lumc.nl [Department of Urology, LUMC, Leiden (Netherlands); Robanus-Maandag, Els C., E-mail: E.C.Robanus@lumc.nl [Department of Human Genetics, LUMC, Leiden (Netherlands); Loewik, Clemens W.G.M., E-mail: C.W.G.M.Lowik@lumc.nl [Department of Endocrinology and Metabolic Diseases, LUMC, Leiden (Netherlands); Oostdijk, Wilma, E-mail: W.Oostdijk@lumc.nl [Department of Pediatrics, Leiden University Medical Centre (LUMC), Leiden (Netherlands); Wit, Jan M., E-mail: J.M.Wit@lumc.nl [Department of Pediatrics, Leiden University Medical Centre (LUMC), Leiden (Netherlands); Karperien, Marcel, E-mail: H.B.J.Karperien@tnw.utwente.nl [MIRA Institute for Biomedical Technology and Technical Medicine, Department of Tissue Regeneration, University of Twente, Zuidhorst Room ZH 144, Drienerlolaan 5, 7522 NB Enschede (Netherlands)

2011-06-10

The canonical Wnt signaling pathway influences the differentiation of mesenchymal cell lineages in a quantitative and qualitative fashion depending on the dose of {beta}-catenin signaling. Adenomatous polyposis coli (Apc) is the critical intracellular regulator of {beta}-catenin turnover. To better understand the molecular mechanisms underlying the role of Apc in regulating the differentiation capacity of skeletal progenitor cells, we have knocked down Apc in the murine mesenchymal stem cell-like KS483 cells by stable expression of Apc-specific small interfering RNA. In routine culture, KSFrt-Apc{sub si} cells displayed a mesenchymal-like spindle shape morphology, exhibited markedly decreased proliferation and increased apoptosis. Apc knockdown resulted in upregulation of the Wnt/{beta}-catenin and the BMP/Smad signaling pathways, but osteogenic differentiation was completely inhibited. This effect could be rescued by adding high concentrations of BMP-7 to the differentiation medium. Furthermore, KSFrt-Apc{sub si} cells showed no potential to differentiate into chondrocytes or adipocytes. These results demonstrate that Apc is essential for the proliferation, survival and differentiation of KS483 cells. Apc knockdown blocks the osteogenic differentiation of skeletal progenitor cells, a process that can be overruled by high BMP signaling.

Expression of P-aPKC-iota, E-cadherin, and beta-catenin related to invasion and metastasis in hepatocellular carcinoma.

Science.gov (United States)

Du, Guang-Sheng; Wang, Jian-Ming; Lu, Jin-Xi; Li, Qiang; Ma, Chao-Qun; Du, Ji-Tao; Zou, Sheng-Quan

2009-06-01

Atypical protein kinase C iota (aPKC-iota) and its associated intracellular molecules, E-cadherin and beta-catenin, are important for cell polarization in tumorigenesis and progression. Expression of aPKC-iota, P-aPKC-iota (activated aPKC-iota), E-cadherin, and beta-catenin in hepatocellular carcinoma (HCC) was measured, and correlation with clinicopathological characteristics of HCC was analyzed. Paraffin-embedded tumor tissue was obtained from patients with HCC after resection without preoperative radiotherapy or chemotherapy. Gene expression was detected by polymerase chain reaction (PCR), and protein expression was detected by immunohistochemistry and Western blot analysis. Expressions of aPKC-iota, P-aPKC-iota, E-cadherin, and beta-catenin were analyzed with relation to the clinicopathological data. The gene and protein expression of aPKC-iota are obviously higher in HCC tissues than that in peritumoral tissues and normal tissues by semiquantitative PCR and immunohistochemistry methods. Accumulation of aPKC-iota in HCC cytoplasm and nucleolus inhibited the later formation of belt-like adherens junctions (AJs) and/or tight junctions (TJs) in cell-cell contact. E-cadherin was reduced and accumulation of cytoplasm beta-catenin was increased in HCC. The expression of aPKC-iota was closely related to pathological differentiation, tumor size, invasion, and metastasis of HCC. Accumulation of cytoplasm aPKC-iota may reflect pathological differentiation, invasion, and metastasis potential of HCC. In this regard, our study on HCC revealed the potential usefulness of aPKC-iota, E-cadherin, and beta-catenin as a prognostic marker, closely related to pathological differentiation, invasion, metastasis, and prognosis of HCC.

Chemoprevention of colon carcinogenesis by polyethylene glycol: suppression of epithelial proliferation via modulation of SNAIL/beta-catenin signaling.

Science.gov (United States)

Roy, Hemant K; Kunte, Dhananjay P; Koetsier, Jennifer L; Hart, John; Kim, Young L; Liu, Yang; Bissonnette, Marc; Goldberg, Michael; Backman, Vadim; Wali, Ramesh K

2006-08-01

Polyethylene glycol (PEG) is one of the most potent chemopreventive agents against colorectal cancer; however, the mechanisms remain largely unexplored. In this study, we assessed the ability of PEG to target cyclin D1-beta-catenin-mediated hyperproliferation in the azoxymethane-treated rat model and the human colorectal cancer cell line, HT-29. Azoxymethane-treated rats were randomized to AIN-76A diet alone or supplemented with 5% PEG-8000. After 30 weeks, animals were euthanized and biopsies of aberrant crypt foci and uninvolved crypts were subjected to immunohistochemical and immunoblot analyses. PEG markedly suppressed both early and late markers of azoxymethane-induced colon carcinogenesis (fractal dimension by 80%, aberrant crypt foci by 64%, and tumors by 74%). In both azoxymethane-treated rats and HT-29 cells treated with 5% PEG-3350 for 24 hours, PEG decreased proliferation (45% and 52%, respectively) and cyclin D1 (78% and 56%, respectively). Because beta-catenin is the major regulator of cyclin D1 in colorectal cancer, we used the T-cell factor (Tcf)-TOPFLASH reporter assay to show that PEG markedly inhibited beta-catenin transcriptional activity. PEG did not alter total beta-catenin expression but rather its nuclear localization, leading us to assess E-cadherin expression (a major determinant of beta-catenin subcellular localization), which was increased by 73% and 71% in the azoxymethane-rat and HT-29 cells, respectively. We therefore investigated the effect of PEG treatment on levels of the negative regulator of E-cadherin, SNAIL, and observed a 50% and 75% decrease, respectively. In conclusion, we show, for the first time, a molecular mechanism through which PEG imparts its antiproliferative and hence profound chemopreventive effect.

Correlation of beta-catenin localization with cyclooxygenase-2 expression and CpG island methylator phenotype (CIMP) in colorectal cancer.

Science.gov (United States)

Kawasaki, Takako; Nosho, Katsuhiko; Ohnishi, Mutsuko; Suemoto, Yuko; Kirkner, Gregory J; Dehari, Reiko; Meyerhardt, Jeffrey A; Fuchs, Charles S; Ogino, Shuji

2007-07-01

The WNT/beta-catenin (CTNNB1) pathway is commonly activated in the carcinogenic process. Cross-talks between the WNT and cyclooxygenase-2 (COX-2 or PTGS2)/prostaglandin pathways have been suggested. The relationship between beta-catenin activation and microsatellite instability (MSI) in colorectal cancer has been controversial. The CpG island methylator phenotype (CIMP or CIMP-high) with widespread promoter methylation is a distinct epigenetic phenotype in colorectal cancer, which is associated with MSI-high. However, no study has examined the relationship between beta-catenin activation and CIMP status. Using 832 population-based colorectal cancer specimens, we assessed beta-catenin localization by immunohistochemistry. We quantified DNA methylation in eight CIMP-specific promoters [CACNA1G, CDKN2A(p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1] by real-time polymerase chain reaction (MethyLight). MSI-high, CIMP-high, and BRAF mutation were associated inversely with cytoplasmic and nuclear beta-catenin expressions (i.e., beta-catenin activation) and associated positively with membrane expression. The inverse relation between beta-catenin activation and CIMP was independent of MSI. COX-2 overexpression correlated with cytoplasmic beta-catenin expression (even after tumors were stratified by CIMP status), but did not correlate significantly with nuclear or membrane expression. In conclusion, beta-catenin activation is inversely associated with CIMP-high independent of MSI status. Cytoplasmic beta-catenin is associated with COX-2 overexpression, supporting the role of cytoplasmic beta-catenin in stabilizing PTGS2 (COX-2) mRNA.

Abrogation of the presenilin 1/beta-catenin interaction and preservation of the heterodimeric presenilin 1 complex following caspase activation.

Science.gov (United States)

Tesco, G; Kim, T W; Diehlmann, A; Beyreuther, K; Tanzi, R E

1998-12-18

beta-Catenin has previously been shown to interact with presenilin 1 (PS1) in transfected cells. Here we report that beta-catenin co-immunoprecipitates with the endogenous C-terminal fragment of presenilin 1 (PS1-CTF) but not with the endogenous CTF of presenilin 2 (PS2-CTF) in H4 human neuroglioma cells. During staurosporine (STS)-induced cell death, beta-catenin and PS1-CTF undergo a caspase-mediated cleavage. After 12 h of STS treatment, the beta-catenin.PS1-CTF interaction is abrogated. While PS1-CTF immunoprecipitated with all caspase-cleaved species of beta-catenin, beta-catenin holoprotein did not co-immunoprecipitate with the "alternative" caspase-derived PS1-CTF (PS1-aCTF). Thus, the abrogation of the beta-catenin.PS1-CTF complex was due to caspase cleavage of PS1-CTF. beta-Catenin co-immunoprecipitated with PS1-NTF, but only when PS1-NTF was associated with PS1-CTF. Even though PS1-NTF.CTF complex stability was not altered by caspase cleavage, its ability to bind beta-catenin was abolished. Thus, while the PS1-NTF.CTF complex is preserved after caspase cleavage, it may no longer be fully functional.

Current status and clinical association of beta-catenin with juvenile nasopharyngeal angiofibroma.

Science.gov (United States)

Mishra, A; Singh, V; Verma, V; Pandey, S; Trivedi, R; Singh, H P; Kumar, S; Dwivedi, R C; Mishra, S C

2016-10-01

A possible role of the APC/beta-catenin pathway in the pathogenesis of sporadic juvenile nasopharyngeal angiofibroma has been suggested. This paper presents its current status and clinical association in our patients. A prospective observational study was conducted at King George Medical University and Central Drug Research Institute, in Lucknow, India. Western blot analysis was undertaken in 16 cases to examine beta-catenin expression. The clinical details were recorded along with follow up observations, to determine associations. Up-regulation of beta-catenin expression was seen in 69 per cent of cases. The clinical variables did not reveal significant differences between patients with extremes of expression (extreme under- vs over-expression). However, absent expression was shown exclusively in young adults aged over 18 years, while enhanced expression was associated with an altered facial profile. Although a beta-catenin association was seen in a subset of our sporadic juvenile nasopharyngeal angiofibroma cases, its expression was not homogeneous. This is in contrast to the Western literature that suggests a universal (homogenous) enhanced expression in the majority. Hence, further research is required to better define its molecular cascade.

Exendin-4 Inhibits Hepatic Lipogenesis by Increasing β-Catenin Signaling.

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Mi Hae Seo

Full Text Available The aim of this study is to investigate whether the beneficial effect of exendin-4 on hepatic steatosis is mediated by β-catenin signaling. After the HepG2 human hepatoma cells were treated with PA for 24 hours, total triglycerides levels were increased in a dose-dependent manner, and the expression levels of perilipin family members were upregulated in cells treated with 400 μM PA. For our in vitro model of hepatic steatosis, HepG2 cells were treated with 400 μM palmitic acid (PA in the presence or absence of 100 nM exendin-4 for 24 hours. PA increased the expression of lipogenic genes, such as sterol regulatory element-binding protein 1c (SREBP-1c, peroxisome proliferator-activated receptor gamma (PPARγ, stearoyl-CoA desaturase 1 (SCD1, fatty acid synthase (FAS, and acetyl-CoA carboxylase (ACC and triglyceride synthesis-involved genes, such as diacylglycerol acyltransferase 1 (DGAT1 and diacylglycerol acyltransferase 2 (DGAT2 in HepG2 cells, whereas exendin-4 treatment significantly prevented the upregulation of SREBP-1c, PPARγ, SCD1, FAS, ACC, DGAT1 and DGAT2. Moreover, exendin-4 treatment increased the expression of phosphorylated glycogen synthase kinase-3 beta (GSK-3β in the cytosolic fraction and the expression of β-catenin and transcription factor 4 (TCF4 in the nuclear fraction. In addition, siRNA-mediated inhibition of β-catenin upregulated the expression of lipogenic transcription factors. The protective effects of exendin-4 on intracellular triglyceride content and total triglyceride levels were not observed in cells treated with the β-catenin inhibitor IWR-1. These data suggest that exendin-4 treatment improves hepatic steatosis by inhibiting lipogenesis via activation of Wnt/β-catenin signaling.

Snail/beta-catenin signaling protects breast cancer cells from hypoxia attack

Energy Technology Data Exchange (ETDEWEB)

Scherbakov, Alexander M., E-mail: alex.scherbakov@gmail.com [Laboratory of Clinical Biochemistry, Institute of Clinical Oncology, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Stefanova, Lidia B.; Sorokin, Danila V.; Semina, Svetlana E. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation); Berstein, Lev M. [Laboratory of Oncoendocrinology, N.N. Petrov Research Institute of Oncology, St. Petersburg 197758 (Russian Federation); Krasil’nikov, Mikhail A. [Laboratory of Molecular Endocrinology, Institute of Carcinogenesis, N.N. Blokhin Cancer Research Centre, Kashirskoye sh. 24, Moscow 115478 (Russian Federation)

2013-12-10

The tolerance of cancer cells to hypoxia depends on the combination of different factors – from increase of glycolysis (Warburg Effect) to activation of intracellular growth/apoptotic pathways. Less is known about the influence of epithelial–mesenchymal transition (EMT) and EMT-associated pathways on the cell sensitivity to hypoxia. The aim of this study was to explore the role of Snail signaling, one of the key EMT pathways, in the mediating of hypoxia response and regulation of cell sensitivity to hypoxia, using as a model in vitro cultured breast cancer cells. Earlier we have shown that estrogen-independent HBL-100 breast cancer cells differ from estrogen-dependent MCF-7 cells with increased expression of Snail1, and demonstrated Snail1 involvement into formation of hormone-resistant phenotype. Because Snail1 belongs to hypoxia-activated proteins, here we studied the influence of Snail1 signaling on the cell tolerance to hypoxia. We found that Snail1-enriched HBL-100 cells were less sensitive to hypoxia-induced growth suppression if compared with MCF-7 line (31% MCF-7 vs. 71% HBL-100 cell viability after 1% O{sub 2} atmosphere for 3 days). Snail1 knock-down enhanced the hypoxia-induced inhibition of cell proliferation giving the direct evidence of Snail1 involvement into cell protection from hypoxia attack. The protective effect of Snail1 was shown to be mediated, at least in a part, via beta-catenin which positively regulated expression of HIF-1-dependent genes. Finally, we found that cell tolerance to hypoxia was accompanied with the failure in the phosphorylation of AMPK – the key energy sensor, and demonstrated an inverse relationship between AMPK and Snail/beta-catenin signaling. Totally, our data show that Snail1 and beta-catenin, besides association with loss of hormone dependence, protect cancer cells from hypoxia and may serve as an important target in the treatment of breast cancer. Moreover, we suggest that the level of these proteins as well

H-Ras activation promotes cytoplasmic accumulation and phosphoinositide 3-OH kinase association of beta-catenin in epidermal keratinocytes

DEFF Research Database (Denmark)

Espada, J; Pérez-Moreno, M; Braga, V M

1999-01-01

The mechanisms underlying downregulation of the cadherin/catenin complexes and beta-catenin signaling during tumor progression are not fully understood. We have analyzed the effect of oncogenic H-Ras on E-cadherin/catenin complex formation/stabilization and beta-catenin distribution in epidermal ...

Global regulator SATB1 recruits beta-catenin and regulates T(H2 differentiation in Wnt-dependent manner.

Directory of Open Access Journals (Sweden)

Dimple Notani

2010-01-01

Full Text Available In vertebrates, the conserved Wnt signalling cascade promotes the stabilization and nuclear accumulation of beta-catenin, which then associates with the lymphoid enhancer factor/T cell factor proteins (LEF/TCFs to activate target genes. Wnt/beta -catenin signalling is essential for T cell development and differentiation. Here we show that special AT-rich binding protein 1 (SATB1, the T lineage-enriched chromatin organizer and global regulator, interacts with beta-catenin and recruits it to SATB1's genomic binding sites. Gene expression profiling revealed that the genes repressed by SATB1 are upregulated upon Wnt signalling. Competition between SATB1 and TCF affects the transcription of TCF-regulated genes upon beta-catenin signalling. GATA-3 is a T helper type 2 (T(H2 specific transcription factor that regulates production of T(H2 cytokines and functions as T(H2 lineage determinant. SATB1 positively regulated GATA-3 and siRNA-mediated knockdown of SATB1 downregulated GATA-3 expression in differentiating human CD4(+ T cells, suggesting that SATB1 influences T(H2 lineage commitment by reprogramming gene expression. In the presence of Dickkopf 1 (Dkk1, an inhibitor of Wnt signalling, GATA-3 is downregulated and the expression of signature T(H2 cytokines such as IL-4, IL-10, and IL-13 is reduced, indicating that Wnt signalling is essential for T(H2 differentiation. Knockdown of beta-catenin also produced similar results, confirming the role of Wnt/beta-catenin signalling in T(H2 differentiation. Furthermore, chromatin immunoprecipitation analysis revealed that SATB1 recruits beta-catenin and p300 acetyltransferase on GATA-3 promoter in differentiating T(H2 cells in a Wnt-dependent manner. SATB1 coordinates T(H2 lineage commitment by reprogramming gene expression. The SATB1:beta-catenin complex activates a number of SATB1 regulated genes, and hence this study has potential to find novel Wnt responsive genes. These results demonstrate that SATB1

WNT10B functional dualism: beta-catenin/Tcf-dependent growth promotion or independent suppression with deregulated expression in cancer.

Science.gov (United States)

Yoshikawa, Hirohide; Matsubara, Kenichi; Zhou, Xiaoling; Okamura, Shu; Kubo, Takahiko; Murase, Yaeko; Shikauchi, Yuko; Esteller, Manel; Herman, James G; Wei Wang, Xin; Harris, Curtis C

2007-11-01

We found aberrant DNA methylation of the WNT10B promoter region in 46% of primary hepatocellular carcinoma (HCC) and 15% of colon cancer samples. Three of 10 HCC and one of two colon cancer cell lines demonstrated low or no expression, and 5-aza-2'deoxycytidine reactivated WNT10B expression with the induction of demethylation, indicating that WNT10B is silenced by DNA methylation in some cancers, whereas WNT10B expression is up-regulated in seven of the 10 HCC cell lines and a colon cancer cell line. These results indicate that WNT10B can be deregulated by either overexpression or silencing in cancer. We found that WNT10B up-regulated beta-catenin/Tcf activity. However, WNT10B-overexpressing cells demonstrated a reduced growth rate and anchorage-independent growth that is independent of the beta-catenin/Tcf activation, because mutant beta-catenin-transduced cells did not suppress growth, and dominant-negative hTcf-4 failed to alleviate the growth suppression by WNT10B. Although WNT10B expression alone inhibits cell growth, it acts synergistically with the fibroblast growth factor (FGF) to stimulate cell growth. WNT10B is bifunctional, one function of which is involved in beta-catenin/Tcf activation, and the other function is related to the down-regulation of cell growth through a different mechanism. We suggest that FGF switches WNT10B from a negative to a positive cell growth regulator.

CHD8, A Novel Beta-Catenin Associated Chromatin Remodeling Enzyme, Regulates Androgen Receptor Mediated Gene Transcription

National Research Council Canada - National Science Library

Bochar, Daniel A

2008-01-01

.... To better understand the function of beta-catenin in AR mediated transcription, we have identified a novel chromatin remodeling enzyme, CHD8, that can associate with beta-catenin and functions in AR...

Endometrial stromal beta-catenin is required for steroid-dependent mesenchymal-epithelial cross talk and decidualization

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Zhang Ling

2012-09-01

Full Text Available Abstract Background Beta-catenin is part of a protein complex associated with adherens junctions. When allowed to accumulate to sufficient levels in its dephosphorylated form, beta-catenin serves as a transcriptional co-activator associated with a number of signaling pathways, including steroid hormone signaling pathways. Methods To investigate the role of beta-catenin in progesterone (P4 signaling and female reproductive physiology, conditional ablation of Ctnnb1 from the endometrial mesenchymal (i.e. stromal and myometrial, but not epithelial, compartment was accomplished using the Amhr2-Cre mice. Experiments were conducted to assess the ability of mutant female mice to undergo pregnancy and pseudopregnancy by or through oil-induced decidualization. The ability of uteri from mutant female mice to respond to estrogen (E2 and P4 was also determined. Results Conditional deletion of Ctnnb1 from the mesenchymal compartment of the uterus resulted in infertility stemming, in part, from complete failure of the uterus to decidualize. E2-stimulated epithelial cell mitosis and edematization were not altered in mutant uteri indicating that the mesenchyme is capable of responding to E2. However, exposure of ovariectomized mutant female mice to a combined E2 and P4 hormone regimen consistent with early pregnancy revealed that mesenchymal beta-catenin is essential for indirectly opposing E2-induced epithelial proliferation by P4 and in some mice resulted in development of endometrial metaplasia. Lastly, beta-catenin is also required for the induced expression of genes that are known to play a fundamental role in decidualization such as Ihh, Ptch1, Gli1 and Muc1 Conclusions Three salient points derive from these studies. First, the findings demonstrate a mechanistic linkage between the P4 and beta-catenin signaling pathways. Second, they highlight an under appreciated role for the mesenchymal compartment in indirectly mediating P4 signaling to the epithelium

Orphan nuclear receptor TLX activates Wnt/beta-catenin signalling to stimulate neural stem cell proliferation and self-renewal.

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Qu, Qiuhao; Sun, Guoqiang; Li, Wenwu; Yang, Su; Ye, Peng; Zhao, Chunnian; Yu, Ruth T; Gage, Fred H; Evans, Ronald M; Shi, Yanhong

2010-01-01

The nuclear receptor TLX (also known as NR2E1) is essential for adult neural stem cell self-renewal; however, the molecular mechanisms involved remain elusive. Here we show that TLX activates the canonical Wnt/beta-catenin pathway in adult mouse neural stem cells. Furthermore, we demonstrate that Wnt/beta-catenin signalling is important in the proliferation and self-renewal of adult neural stem cells in the presence of epidermal growth factor and fibroblast growth factor. Wnt7a and active beta-catenin promote neural stem cell self-renewal, whereas the deletion of Wnt7a or the lentiviral transduction of axin, a beta-catenin inhibitor, led to decreased cell proliferation in adult neurogenic areas. Lentiviral transduction of active beta-catenin led to increased numbers of type B neural stem cells in the subventricular zone of adult brains, whereas deletion of Wnt7a or TLX resulted in decreased numbers of neural stem cells retaining bromodeoxyuridine label in the adult brain. Both Wnt7a and active beta-catenin significantly rescued a TLX (also known as Nr2e1) short interfering RNA-induced deficiency in neural stem cell proliferation. Lentiviral transduction of an active beta-catenin increased cell proliferation in neurogenic areas of TLX-null adult brains markedly. These results strongly support the hypothesis that TLX acts through the Wnt/beta-catenin pathway to regulate neural stem cell proliferation and self-renewal. Moreover, this study suggests that neural stem cells can promote their own self-renewal by secreting signalling molecules that act in an autocrine/paracrine mode.

Glycogen synthase kinase 3 beta inhibits microRNA-183-96-182 cluster via the β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

Science.gov (United States)

Tang, Xiaoli; Zheng, Dong; Hu, Ping; Zeng, Zongyue; Li, Ming; Tucker, Lynne; Monahan, Renee; Resnick, Murray B; Liu, Manran; Ramratnam, Bharat

2014-03-01

Glycogen synthase kinase 3 beta (GSK3β) is a critical protein kinase that phosphorylates numerous proteins in cells and thereby impacts multiple pathways including the β-Catenin/TCF/LEF-1 pathway. MicroRNAs (miRs) are a class of noncoding small RNAs of ∼22 nucleotides in length. Both GSK3β and miR play myriad roles in cell functions including stem cell development, apoptosis, embryogenesis and tumorigenesis. Here we show that GSK3β inhibits the expression of miR-96, miR-182 and miR-183 through the β-Catenin/TCF/LEF-1 pathway. Knockout of GSK3β in mouse embryonic fibroblast cells increases expression of miR-96, miR-182 and miR-183, coinciding with increases in the protein level and nuclear translocation of β-Catenin. In addition, overexpression of β-Catenin enhances the expression of miR-96, miR-182 and miR-183 in human gastric cancer AGS cells. GSK3β protein levels are decreased in human gastric cancer tissue compared with surrounding normal gastric tissue, coinciding with increases of β-Catenin protein, miR-96, miR-182, miR-183 and primary miR-183-96-182 cluster (pri-miR-183). Furthermore, suppression of miR-183-96-182 cluster with miRCURY LNA miR inhibitors decreases the proliferation and migration of AGS cells. Knockdown of GSK3β with siRNA increases the proliferation of AGS cells. Mechanistically, we show that β-Catenin/TCF/LEF-1 binds to the promoter of miR-183-96-182 cluster gene and thereby activates the transcription of the cluster. In summary, our findings identify a novel role for GSK3β in the regulation of miR-183-96-182 biogenesis through β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

Inhibition of beta-catenin and KRAS expressions by Piper betle in azoxymethane-induced colon cancer of male Fischer 344 rats.

Science.gov (United States)

Esa, Faezah; Ngah, Wan Zurinah Wan; Jamal, A Rahman A; Mohd Yusof, Yasmin Anum

2013-12-01

To investigate the chemopreventive effect of Piper betle (PB) on preneoplastic lesions (aberrant crypt foci [ACF]) induced by azoxymethane (AOM) in rats and its effect on colorectal cancer biomarkers (beta-catenin, KRAS, p53 and p21). A total of 32 male Fischer 344 rats were divided into phase 1 and phase 2 groups (8 and 24 weeks of AOM administration, respectively). Each phase was divided into 4 groups: control or normal saline (NS) (1 mL/kg), AOM (15 mg/kg body weight, once weekly for 2 weeks), PB (75 mg/kg body weight) and AOM + PB. PB was force-fed to rats a week after the second dose of AOM and NS. The colon was cut open longitudinally for methylene blue and immunohistochemistry staining. AOM administration showed formation of ACF at 8 and 24 weeks. PB, however, did not reduce ACF formation at either week, but it managed to reduce beta-catenin expression and KRAS found highly expressed in the AOM group of phase 1 rats. No immunoreactivities of p53 and p21 were detected in phase 2 rats, but instead inflammatory cells were visible in between the lesions. PB may act as a potential chemopreventive agent in the early stage of colon carcinogenesis by suppressing the expressions of beta-catenin and KRAS.

Intracellular Wnt/Beta-Catenin Signaling Underlying 17beta-Estradiol-Induced Matrix Metalloproteinase 9 Expression in Human Endometriosis.

Science.gov (United States)

Zhang, Ling; Xiong, Wenqian; Xiong, Yao; Liu, Hengwei; Li, Na; Du, Yu; Liu, Yi

2016-03-01

Extracellular matrix remodeling is necessary for ectopic endometrium implantation. Many studies have shown an increased expression of matrix metalloproteinase 9 (MMP9) in the ectopic endometrium of endometriosis. However, the signaling pathways and cellular effects related to this process remain incompletely elucidated. The objective of our study was to investigate the association between MMP9 and the Wnt signaling pathway under the regulation of 17beta-estradiol (E2) in endometrial stromal cells. We found that MMP9 was elevated in tissues from women with endometriosis compared with normal women. Furthermore, MMP9 and beta-catenin increased concurrently in a time- and dose-dependent manner after E2 treatment. To clarify the relationship between MMP9 and beta-catenin, we performed luciferase promoter reporter and chromatin immunoprecipitation assays. A beta-catenin/TCF3/LEF1 complex bound to a specific site on the MMP9 promoter that promoted MMP9 gene and protein expression. The promotion of MMP9 by the Wnt signaling pathway under the regulation of E2 may contribute to the pathophysiology of this disease. © 2016 by the Society for the Study of Reproduction, Inc.

Thermodynamics in Neurodegenerative Diseases: Interplay Between Canonical WNT/Beta-Catenin Pathway-PPAR Gamma, Energy Metabolism and Circadian Rhythms.

Science.gov (United States)

Vallée, Alexandre; Lecarpentier, Yves; Guillevin, Rémy; Vallée, Jean-Noël

2018-03-23

Entropy production rate is increased by several metabolic and thermodynamics abnormalities in neurodegenerative diseases (NDs). Irreversible processes are quantified by changes in the entropy production rate. This review is focused on the opposing interactions observed in NDs between the canonical WNT/beta-catenin pathway and PPAR gamma and their metabolic and thermodynamic implications. In amyotrophic lateral sclerosis and Huntington's disease, WNT/beta-catenin pathway is upregulated, whereas PPAR gamma is downregulated. In Alzheimer's disease and Parkinson's disease, WNT/beta-catenin pathway is downregulated while PPAR gamma is upregulated. The dysregulation of the canonical WNT/beta-catenin pathway is responsible for the modification of thermodynamics behaviors of metabolic enzymes. Upregulation of WNT/beta-catenin pathway leads to aerobic glycolysis, named Warburg effect, through activated enzymes, such as glucose transporter (Glut), pyruvate kinase M2 (PKM2), pyruvate dehydrogenase kinase 1(PDK1), monocarboxylate lactate transporter 1 (MCT-1), lactic dehydrogenase kinase-A (LDH-A) and inactivation of pyruvate dehydrogenase complex (PDH). Downregulation of WNT/beta-catenin pathway leads to oxidative stress and cell death through inactivation of Glut, PKM2, PDK1, MCT-1, LDH-A but activation of PDH. In addition, in NDs, PPAR gamma is dysregulated, whereas it contributes to the regulation of several key circadian genes. NDs show many dysregulation in the mediation of circadian clock genes and so of circadian rhythms. Thermodynamics rhythms operate far-from-equilibrium and partly regulate interactions between WNT/beta-catenin pathway and PPAR gamma. In NDs, metabolism, thermodynamics and circadian rhythms are tightly interrelated.

Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling.

Directory of Open Access Journals (Sweden)

Robert D Prinz

Full Text Available The glycosaminoglycan chondroitin sulfate is a critical component of proteoglycans on the cell surface and in the extracellular matrix. As such, chondroitin sulfate side chains and the sulfation balance of chondroitin play important roles in the control of signaling pathways, and have a functional importance in human disease. In contrast, very little is known about the roles of chondroitin sulfate molecules and sulfation patterns during mammalian development and cell lineage specification. Here, we report a novel biphasic role of chondroitin sulfate in the specification of the cardiac cell lineage during embryonic stem cell differentiation through modulation of Wnt/beta-catenin signaling. Lineage marker analysis demonstrates that enzymatic elimination of endogenous chondroitin sulfates leads to defects specifically in cardiac differentiation. This is accompanied by a reduction in the number of beating cardiac foci. Mechanistically, we show that endogenous chondroitin sulfate controls cardiac differentiation in a temporal biphasic manner through inhibition of the Wnt/beta-catenin pathway, a known regulatory pathway for the cardiac lineage. Treatment with a specific exogenous chondroitin sulfate, CS-E, could mimic these biphasic effects on cardiac differentiation and Wnt/beta-catenin signaling. These results establish chondroitin sulfate and its sulfation balance as important regulators of cardiac cell lineage decisions through control of the Wnt/beta-catenin pathway. Our work suggests that targeting the chondroitin biosynthesis and sulfation machinery is a novel promising avenue in regenerative strategies after heart injury.

Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling.

Science.gov (United States)

Prinz, Robert D; Willis, Catherine M; van Kuppevelt, Toin H; Klüppel, Michael

2014-01-01

The glycosaminoglycan chondroitin sulfate is a critical component of proteoglycans on the cell surface and in the extracellular matrix. As such, chondroitin sulfate side chains and the sulfation balance of chondroitin play important roles in the control of signaling pathways, and have a functional importance in human disease. In contrast, very little is known about the roles of chondroitin sulfate molecules and sulfation patterns during mammalian development and cell lineage specification. Here, we report a novel biphasic role of chondroitin sulfate in the specification of the cardiac cell lineage during embryonic stem cell differentiation through modulation of Wnt/beta-catenin signaling. Lineage marker analysis demonstrates that enzymatic elimination of endogenous chondroitin sulfates leads to defects specifically in cardiac differentiation. This is accompanied by a reduction in the number of beating cardiac foci. Mechanistically, we show that endogenous chondroitin sulfate controls cardiac differentiation in a temporal biphasic manner through inhibition of the Wnt/beta-catenin pathway, a known regulatory pathway for the cardiac lineage. Treatment with a specific exogenous chondroitin sulfate, CS-E, could mimic these biphasic effects on cardiac differentiation and Wnt/beta-catenin signaling. These results establish chondroitin sulfate and its sulfation balance as important regulators of cardiac cell lineage decisions through control of the Wnt/beta-catenin pathway. Our work suggests that targeting the chondroitin biosynthesis and sulfation machinery is a novel promising avenue in regenerative strategies after heart injury.

Wnt/beta-Catenin, Foxa2, and CXCR4 Axis Controls Prostate Cancer Progression

Science.gov (United States)

2014-07-01

NT1 cells that over-expressing Foxa2. The reason we used NT1 cells for the Foxa2 over-expressing experiments is that NT1 is an AR-expressing... cells . We have also established NT1 cells over-expressing a dominant active beta-catenin. We have characterized these cells . Our research found: 1...expression profiles of control NT1 , NT1 /Foxa2, and NT1 /beta-catenin cells Figure 1. We did RT-PCR to examine the expression of key

Lithium chloride increases the production of amyloid-beta peptide independently from its inhibition of glycogen synthase kinase 3.

Science.gov (United States)

Feyt, Christine; Kienlen-Campard, Pascal; Leroy, Karelle; N'Kuli, Francisca; Courtoy, Pierre J; Brion, Jean-Pierre; Octave, Jean-Noël

2005-09-30

Glycogen synthase kinase 3 (GSK3) is able to phosphorylate tau at many sites that are found to be phosphorylated in paired helical filaments in Alzheimer disease. Lithium chloride (LiCl) efficiently inhibits GSK3 and was recently reported to also decrease the production of amyloid-beta peptide (Abeta) from its precursor, the amyloid precursor protein. Therefore, lithium has been proposed as a combined therapeutic agent, inhibiting both the hyperphosphorylation of tau and the production of Abeta. Here, we demonstrate that the inhibition of GSK3 by LiCl induced the nuclear translocation of beta-catenin in Chinese hamster ovary cells and rat cultured neurons, in which a decrease in tau phosphorylation was observed. In both cellular models, a nontoxic concentration of LiCl increased the production of Abeta by increasing the beta-cleavage of amyloid precursor protein, generating more substrate for an unmodified gamma-secretase activity. SB415286, another GSK3 inhibitor, induced the nuclear translocation of beta-catenin and slightly decreased Abeta production. It is concluded that the LiCl-mediated increase in Abeta production is not related to GSK3 inhibition.

The Ewing sarcoma secretome and its response to activation of Wnt/beta-catenin signaling.

Science.gov (United States)

Hawkins, Allegra G; Basrur, Venkatesha; da Veiga Leprevost, Felipe; Pedersen, Elisabeth; Sperring, Colin; Nesvizhskii, Alexey I; Lawlor, Elizabeth R

2018-01-31

Tumor: tumor microenvironment (TME) interactions are critical for tumor progression and the composition and structure of the local extracellular matrix (ECM) are key determinants of tumor metastasis. We recently reported that activation of Wnt/beta-catenin signaling in Ewing sarcoma cells induces widespread transcriptional changes that are associated with acquisition of a metastatic tumor phenotype. Significantly, ECM protein-encoding genes were found to be enriched among Wnt/beta-catenin induced transcripts, leading us to hypothesize that activation of canonical Wnt signaling might induce changes in the Ewing sarcoma secretome. To address this hypothesis, conditioned media from Ewing sarcoma cell lines cultured in the presence or absence of Wnt3a was collected for proteomic analysis. Label-free mass spectrometry was used to identify and quantify differentially secreted proteins. We then used in silico databases to identify only proteins annotated as secreted. Comparison of the secretomes of two Ewing sarcoma cell lines revealed numerous shared proteins, as well as a degree of heterogeneity, in both basal and Wnt-stimulated conditions. Gene set enrichment analysis of secreted proteins revealed that Wnt stimulation reproducibly resulted in increased secretion of proteins involved in ECM organization, ECM receptor interactions, and collagen formation. In particular, Wnt-stimulated Ewing sarcoma cells upregulated secretion of structural collagens, as well as matricellular proteins, such as the metastasis-associated protein, tenascin C (TNC). Interrogation of published databases confirmed reproducible correlations between Wnt/beta-catenin activation and TNC and COL1A1 expression in patient tumors. In summary, this first study of the Ewing sarcoma secretome reveals that Wnt/beta-catenin activated tumor cells upregulate secretion of ECM proteins. Such Wnt/beta-catenin mediated changes are likely to impact on tumor: TME interactions that contribute to metastatic

Inhibition of β-catenin-mediated transactivation by flavanone in AGS gastric cancer cells

International Nuclear Information System (INIS)

Park, Chi Hoon; Hahm, Eun Ryeong; Lee, Ju Hyung; Jung, Kyung Chae; Yang, Chul Hak

2005-01-01

Recently, data which prove that Wnt pathway activation may be an early event in multistep carcinogenesis in the stomach have been accumulating. We examined the effect of flavanone against β-catenin/Tcf signaling in AGS gastric cancer cells. Reporter gene assay showed that flavanone inhibited β-catenin/Tcf signaling efficiently. In addition, the inhibition of β-catenin/Tcf signaling by flavanone in HEK293 cells transiently transfected with constitutively mutant β-catenin gene, whose product is not phosphorylated by GSK3β, indicates that its inhibitory mechanism was related to β-catenin itself or downstream components. To investigate the precise inhibitory mechanism, we performed immunofluorescence, Western blot, and EMSA. As a result, our data revealed that there is no change of β-catenin distribution and of nuclear β-catenin levels through flavanone. In addition, the binding of Tcf complexes to DNA is not influenced by flavanone. The β-catenin/Tcf transcriptional target gene cyclinD1 was downregulated by flavanone. These data suggest that flavanone inhibits the transcription of β-catenin/Tcf responsive genes, by modulating Tcf activity without disrupting β-catenin/Tcf complex formation

MAPK/ERK and Wnt/{beta}-Catenin pathways are synergistically involved in proliferation of Sca-1 positive hepatic progenitor cells

Energy Technology Data Exchange (ETDEWEB)

Jin, Caixia [Department of Surgery, University of North Carolina at Chapel Hill (United States); Department of Medical Genetics and Cell Biology, Ningxia Medical University, Yinchuan 750004 (China); Samuelson, Lisa; Cui, Cai-Bin; Sun, Yangzhong [Department of Surgery, University of North Carolina at Chapel Hill (United States); Gerber, David A., E-mail: david_gerber@med.unc.edu [Department of Surgery, University of North Carolina at Chapel Hill (United States); Lineberger Cancer Center, University of North Carolina at Chapel Hill (United States)

2011-06-17

Highlights: {yields} Activation of MAPK/ERK pathway with epidermal growth factor (EGF) significantly increased Sca-1{sup +} HPC proliferation and colony formation. {yields} Activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. {yields} Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation and maintain long-term HPCs in vitro. -- Abstract: Hepatic progenitor cells (HPCs) persist in adulthood and have the potential to play a major role in regenerating diseased liver. However, the signaling pathways that both directly and indirectly regulate HPCs' self-renewal and differentiation remain elusive. Previously, we identified a bipotent, stem cell antigen-1 (Sca-1) positive HPC population from naive adult liver tissue. In the present study, we aimed to investigate the involvement of various signaling pathways in Sca-1{sup +} HPC proliferation. Epidermal growth factor (EGF) supplementation shows a significant increase in Sca-1{sup +} HPC proliferation and colony formation while stimulating phosphorylation of ERK1/2 and activating the induction of Cyclin D1. There were no demonstrable effects of EGF on Akt. The MEK inhibitor, PD0325901, inhibits proliferation and ERK1/2 phosphorylation while also suppressing the expression of Cyclin D1. In addition, activation of either IL-6/STAT3 or Wnt/{beta}-Catenin pathway did not independently support cell proliferation and colony formation of HPCs. The Wnt/{beta}-Catenin pathway can cooperate with EGF to significantly promote HPC colony formation ratio and maintain long-term HPC in vitro. The data indicates that the MAPK/ERK pathway is both essential and critical for HPC proliferation, and the Wnt signaling pathway is not sufficient, while it works synergistically with the MAPK/ERK signaling pathway to promote HPC proliferation.

Polycyclic aromatic hydrocarbons and dibutyl phthalate disrupt dorsal-ventral axis determination via the Wnt/{beta}-catenin signaling pathway in zebrafish embryos

Energy Technology Data Exchange (ETDEWEB)

Fairbairn, Elise A., E-mail: efairbairn@ucdavis.edu [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Bonthius, Jessica, E-mail: jessica.bonthius@gmail.com [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Cherr, Gary N., E-mail: gncherr@ucdavis.edu [University of California Davis, Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, CA 94923 (United States); Department of Environmental Toxicology, University of California Davis, Davis, CA 95616 (United States); Department of Nutrition, University of California Davis, Davis, CA 95616 (United States)

2012-11-15

The canonical Wnt/{beta}-catenin signaling pathway is critical during early teleost development for establishing the dorsal-ventral axis. Within this pathway, GSK-3{beta}, a key regulatory kinase in the Wnt pathway, regulates {beta}-catenin degradation and thus the ability of {beta}-catenin to enter nuclei, where it can activate expression of genes that have been linked to the specification of the dorsal-ventral axis. In this study, we describe the morphological abnormalities that resulted in zebrafish embryos when axis determination was disrupted by environmental contaminants. These abnormalities were linked to abnormal nuclear accumulation of {beta}-catenin. Furthermore, we demonstrated that the developmental abnormalities and altered nuclear {beta}-catenin accumulation occurred when embryos were exposed to commercial GSK-3{beta} inhibitors. Zebrafish embryos were exposed to commercially available GSK-3 inhibitors (GSK-3 Inhibitor IX and 1-azakenpaullone), or common environmental contaminants (dibutyl phthalate or the polycyclic aromatic hydrocarbons phenanthrene and fluorene) from the 2 to 8-cell stage through the mid-blastula transition (MBT). These embryos displayed morphological abnormalities at 12.5 h post-fertilization (hpf) that were comparable to embryos exposed to lithium chloride (LiCl) (300 mM LiCl for 10 min, prior to the MBT), a classic disruptor of embryonic axis determination. Whole-mount immunolabeling and laser scanning confocal microscopy were used to localize {beta}-catenin. The commercial GSK-3 Inhibitors as well as LiCl, dibutyl phthalate, fluorene and phenanthrene all induced an increase in the levels of nuclear {beta}-catenin throughout the embryo, indicating that the morphological abnormalities were a result of disruption of Wnt/{beta}-catenin signaling during dorsal-ventral axis specification. The ability of environmental chemicals to directly or indirectly target GSK-3{beta} was assessed. Using Western blot analysis, the ability of these

Regulated binding of PTP1B-like phosphatase to N-cadherin: control of cadherin-mediated adhesion by dephosphorylation of beta-catenin

Science.gov (United States)

1996-01-01

, results in the accumulation of phosphorylated tyrosine residues on beta-catenin, uncoupling of N-cadherin from its association with the actin containing cytoskeleton, and loss of N- cadherin function. We now report that binding of these ligands to the GalNAcPTase results in the absence of the PTP1B-like phosphatase from its association with N-cadherin as well as the loss of the tyrosine kinase and tyrosine phosphatase activities that otherwise co- precipitate with N-cadherin. Control antibodies and proteoglycans have no such effect. This effect is similar to that observed with tyrosine kinase inhibitors, suggesting that the GalNAcPTase/proteoglycan interaction inhibits a tyrosine kinase, thereby preventing the phosphorylation of the PTP1B-like phosphatase, and its association with N-cadherin. Taken together these data indicate that a PTP1B-like tyrosine phosphatase can regulate N-cadherin function through its ability to dephosphorylate beta-catenin and that the association of the phosphatase with N-cadherin is regulated via the interaction of the GalNAcPTase with its proteoglycan ligand. In this manner the GalNAcPTase-proteoglycan interaction may play a major role in morphogenetic cell and tissue interactions during development. PMID:8707857

Distinct hydrophobic “patches” in the N- and C-tails of beta-catenin contribute to nuclear transport

Energy Technology Data Exchange (ETDEWEB)

Sharma, Manisha; Jamieson, Cara; Lui, Christina [Center for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia); Henderson, Beric R., E-mail: beric.henderson@sydney.edu.au [Center for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia)

2016-11-01

β-catenin is a key mediator of Wnt signaling and its deregulated nuclear accumulation can drive cancer progression. While the central armadillo (Arm) repeats of β-catenin stimulate nuclear entry, the N- and C-terminal “tail” sequences are thought to regulate turnover and transactivation. We show here that the N- and C-tails are also potent transport sequences. The unstructured tails of β-catenin, when individually fused to a GFP-reporter, could enter and exit the nucleus rapidly in live cells. Proximity ligation assays and pull-down assays identified a weak interaction between the tail sequences and the FG-repeats of nucleoporins, consistent with a possible direct translocation of β-catenin through the nuclear pore complex. Extensive alanine mutagenesis of the tail sequences revealed that nuclear translocation of β-catenin was dependent on specific uniformly distributed patches of hydrophobic residues, whereas the mutagenesis of acidic amino acids had no effect. Moreover, the mutation of hydrophobic patches within the N-tail and C-tail of full length β-catenin reduced nuclear transport rate and diminished its ability to activate transcription. We propose that the tail sequences can contribute to β-catenin transport and suggest a possible similar role for hydrophobic unstructured regions in other proteins. - Highlights: • We show that the N- and C-tails of beta-catenin possess nuclear transport activity. • Nuclear transport of the N- or C-tails requires specific hydrophobic amino acids. • Mutagenesis of the N-terminus diminished nuclear entry of full-length beta-catenin. • We propose the N-tail contributes to beta-catenin nuclear entry and transactivation.

Tissue- and stage-specific Wnt target gene expression is controlled subsequent to beta-catenin recruitment to cis-regulatory modules

NARCIS (Netherlands)

Nakamura, Y.; de Paiva Alves, E.; Veenstra, G.J.C.; Hoppler, S.

2016-01-01

Key signalling pathways, such as canonical Wnt/beta-catenin signalling, operate repeatedly to regulate tissue- and stage-specific transcriptional responses during development. Although recruitment of nuclear beta-catenin to target genomic loci serves as the hallmark of canonical Wnt signalling,

Correlation of cytoplasmic beta-catenin and cyclin D1 overexpression during thyroid carcinogenesis around Semipalatinsk nuclear test site.

Science.gov (United States)

Meirmanov, Serik; Nakashima, Masahiro; Kondo, Hisayoshi; Matsufuji, Reiko; Takamura, Noboru; Ishigaki, Katsu; Ito, Masahiro; Prouglo, Yuri; Yamashita, Shunichi; Sekine, Ichiro

2003-06-01

The Semipalatinsk nuclear test site (SNTS), the Republic of Kazakhstan, has been contaminated by radioactive fallout. The alteration of oncogenic molecules in thyroid cancer around the SNTS was considered worthy of analysis because it presented the potential to elucidate the relationship between radiation exposure and thyroid cancer. This study aimed to analyze both beta-catenin and cyclin D1 expressions in thyroid carcinomas around the SNTS. We examined nine cases of chronic thyroiditis, eight cases of follicular adenomas, and 23 cases of papillary carcinomas. Immunohistochemically, all carcinomas displayed a strong cytosolic beta-catenin expression, while both chronic thyroiditis and follicular adenomas showed a significantly lower cytoplasmic beta-catenin (22.2% and 37.5%, respectively). No cyclin D1 immunoreactivity was evident in chronic thyroiditis. In contrast, 62.5% of follicular adenomas and 87.0% of papillary carcinoma showed cyclin D1 overexpression. Additionally, a strong correlation between cytoplasmic beta-catenin and cyclin D1 expression was suggested in thyroid tumors. This study revealed a higher prevalence of both aberrant beta-catenin expression and cyclin D1 overexpression in papillary thyroid cancers around the SNTS than sporadic cases. The analysis of the alteration of the Wnt signaling-related molecules in thyroid cancer around the SNTS may be important to gain an insight into radiation-induced thyroid tumorigenesis.

Activation of the Wnt/β-catenin pathway in pancreatic beta cells during the compensatory islet hyperplasia in prediabetic mice

International Nuclear Information System (INIS)

Maschio, D.A.; Oliveira, R.B.; Santos, M.R.; Carvalho, C.P.F.; Barbosa-Sampaio, H.C.L.; Collares-Buzato, C.B.

2016-01-01

The Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, plays a role in cell proliferation and differentiation in several tissues/organs. It has been recently described in humans a relationship between type 2 diabetes (T2DM) and mutation in the gene encoding the transcription factor TCF7L2 associated to the Wnt/β-catenin pathway. In the present study, we demonstrated that hyperplastic pancreatic islets from prediabetic mice fed a high-fat diet (HFD) for 60 d displayed nuclear translocation of active β-catenin associated with significant increases in protein content and gene expression of β-catenin as well as of cyclins D1, D2 and c-Myc (target genes of the Wnt pathway) but not of Tcf7l2 (the transcription factor). Meanwhile, these alterations were not observed in pancreatic islets from 30 d HFD-fed mice, that do not display significant beta cell hyperplasia. These data suggest that the Wnt/β-catenin pathway is activated in pancreatic islets during prediabetes and may play a role in the induction of the compensatory beta cell hyperplasia observed at early phase of T2DM. - Highlights: • Exposure to high-fat diet for 60 days induced prediabetes and beta cell mass expansion. • Hyperplastic pancreatic islets displayed nuclear translocation of active β-catenin. • Hyperplastic islets showed increased expression of target genes of the Wnt/β-catenin pathway. • Wnt/β-catenin pathway is activated during compensatory beta cell hyperplasia in mice.

Helicobacter pylori promotes angiogenesis depending on Wnt/beta-catenin-mediated vascular endothelial growth factor via the cyclooxygenase-2 pathway in gastric cancer

International Nuclear Information System (INIS)

Liu, Ningning; Zhou, Ning; Chai, Ni; Liu, Xuan; Jiang, Haili; Wu, Qiong; Li, Qi

2016-01-01

Helicobacter pylori is an important pathogenic factor in gastric carcinogenesis. Angiogenesis (i.e., the growth of new blood vessels) is closely associated with the incidence and development of gastric cancer. Our previous study found that COX-2 stimulates gastric cancer cells to induce expression of the angiogenic growth factor VEGF through an unknown mechanism. Therefore, the aim of this study was to clarify the role of angiogenesis in H. pylori-induced gastric cancer development. To clarify the relationship between H. pylori infection and angiogenesis, we first investigated H. pylori colonization, COX-2, VEGF, beta-catenin expression, and microvessel density (MVD) in gastric cancer tissues from 106 patients. In addition, COX-2, phospho-beta-catenin, and beta-catenin expression were measured by western blotting, and VEGF expression was measured by ELISA in H. pylori-infected SGC7901 and MKN45 human gastric cancer cells. H. pylori colonization occurred in 36.8 % of gastric carcinoma samples. Furthermore, COX-2, beta-catenin, and VEGF expression, and MVD were significantly higher in H. pylori-positive gastric cancer tissues than in H. pylori-negative gastric cancer tissues (P < 0.01). H. pylori infection was not related to sex or age in gastric cancer patients, but correlated with the depth of tumor invasion, lymph node metastasis, and tumor–node–metastasis stage (P < 0.05) and correlated with the COX-2 expression and beta-catenin expression(P < 0.01). Further cell experiments confirmed that H. pylori infection upregulated VEGF in vitro. Further analysis revealed that H. pylori-induced VEGF expression was mediated by COX-2 via activation of the Wnt/beta-catenin pathway. The COX-2/Wnt/beta-catenin/VEGF pathway plays an important role in H. pylori-associated gastric cancer development. The COX-2/Wnt/beta-catenin pathway is therefore a novel therapeutic target for H. pylori-associated gastric cancers

E-cadherin homophilic ligation inhibits cell growth and epidermal growth factor receptor signaling independently of other cell interactions

DEFF Research Database (Denmark)

Perrais, Michaël; Chen, Xiao; Perez-Moreno, Mirna

2007-01-01

growth inhibitory signals. To address this question, we have selectively formed E-cadherin homophilic bonds at the cell surface of isolated epithelial cells by using functionally active recombinant E-cadherin protein attached to microspheres. We find that E-cadherin ligation alone reduces the frequency...... of cells entering the S phase, demonstrating that E-cadherin ligation directly transduces growth inhibitory signals. E-cadherin binding to beta-catenin is required for cell growth inhibition, but beta-catenin/T-cell factor transcriptional activity is not involved in growth inhibition resulting from...... homophilic binding. Neither E-cadherin binding to p120-catenin nor beta-catenin binding to alpha-catenin, and thereby the actin cytoskeleton, is required for growth inhibition. E-cadherin ligation also inhibits epidermal growth factor (EGF) receptor-mediated growth signaling by a beta...

The RNA-binding protein KSRP promotes decay of beta-catenin mRNA and is inactivated by PI3K-AKT signaling

DEFF Research Database (Denmark)

Gherzi, Roberto; Trabucchi, Michele; Ponassi, Marco

2006-01-01

Beta-catenin plays an essential role in several biological events including cell fate determination, cell proliferation, and transformation. Here we report that beta-catenin is encoded by a labile transcript whose half-life is prolonged by Wnt and phosphatidylinositol 3-kinase-AKT signaling. AKT...

Activation of the Wnt/{beta}-catenin signaling pathway is associated with glial proliferation in the adult spinal cord of ALS transgenic mice

Energy Technology Data Exchange (ETDEWEB)

Chen, Yanchun [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Guan, Yingjun, E-mail: guanyj@wfmc.edu.cn [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong (China); Liu, Huancai [Department of Orthopedic, Affiliated Hospital, Weifang Medical University, Weifang, Shandong (China); Wu, Xin; Yu, Li; Wang, Shanshan; Zhao, Chunyan; Du, Hongmei [Department of Histology and Embryology, Weifang Medical University, Weifang, Shandong (China); Wang, Xin, E-mail: xwang@rics.bwh.harvard.edu [Department of Neurosurgery, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

2012-04-06

Highlights: Black-Right-Pointing-Pointer Wnt3a and Cyclin D1 were upregulated in the spinal cord of the ALS mice. Black-Right-Pointing-Pointer {beta}-catenin translocated from the cell membrane to the nucleus in the ALS mice. Black-Right-Pointing-Pointer Wnt3a, {beta}-catenin and Cyclin D1 co-localized for astrocytes were all increased. Black-Right-Pointing-Pointer BrdU/Cyclin D1 double-positive cells were increased in the spinal cord of ALS mice. Black-Right-Pointing-Pointer BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. -- Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive and fatal loss of motor neurons. In ALS, there is a significant cell proliferation in response to neurodegeneration; however, the exact molecular mechanisms of cell proliferation and differentiation are unclear. The Wnt signaling pathway has been shown to be involved in neurodegenerative processes. Wnt3a, {beta}-catenin, and Cyclin D1 are three key signaling molecules of the Wnt/{beta}-catenin signaling pathway. We determined the expression of Wnt3a, {beta}-catenin, and Cyclin D1 in the adult spinal cord of SOD1{sup G93A} ALS transgenic mice at different stages by RT-PCR, Western blot, and immunofluorescence labeling techniques. We found that the mRNA and protein of Wnt3a and Cyclin D1 in the spinal cord of the ALS mice were upregulated compared to those in wild-type mice. In addition, {beta}-catenin translocated from the cell membrane to the nucleus and subsequently activated transcription of the target gene, Cyclin D1. BrdU and Cyclin D1 double-positive cells were increased in the spinal cord of these mice. Moreover, Wnt3a, {beta}-catenin, and Cyclin D1 were also expressed in both neurons and astrocytes. The expression of Wnt3a, {beta}-catenin or Cyclin D1 in mature GFAP{sup +} astrocytes increased. Moreover, BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. Our findings suggest that

Targeting the Wnt/beta-catenin pathway in cancer: Update on effectors and inhibitors.

Science.gov (United States)

Krishnamurthy, Nithya; Kurzrock, Razelle

2018-01-01

The Wnt/beta-catenin pathway is a family of proteins that is implicated in many vital cellular functions such as stem cell regeneration and organogenesis. Several intra-cellular signal transduction pathways are induced by Wnt, notably the Wnt/beta-catenin dependent pathway or canonical pathway and the non-canonical or beta-catenin-independent pathway; the latter includes the Wnt/Ca2+ and Planar Cell Polarity pathway (PCP). Wnt activation occurs at the intestinal crypt floor, and is critical to optimal maintenance of stem cells. Colorectal cancers show evidence of Wnt signaling pathway activation and this is associated with loss of function of the tumor regulator APC. Wnt activation has been observed in breast, lung, and hematopoietic malignancies and contributes to tumor recurrence. The Wnt pathway cross talks with the Notch and Sonic Hedgehog pathways, which has implications for therapeutic interventions in cancers. There are significant challenges in targeting the Wnt pathway, including finding agents that are efficacious without damaging the system of normal somatic stem cell function in cellular repair and tissue homeostasis. Here, we comprehensively review the Wnt pathway and its interactions with the Notch and Sonic Hedgehog pathways. We present the state of the field in effectors and inhibitors of Wnt signaling, including updates on clinical trials in various cancers with inhibitors of Wnt, Notch, and Sonic Hedgehog. Copyright © 2017 Elsevier Ltd. All rights reserved.

The interplay of the aryl hydrocarbon receptor and beta-catenin alters both AhR-dependent transcription and Wnt/beta-catenin signaling in liver progenitors

Czech Academy of Sciences Publication Activity Database

Procházková, Jiřina; Kabátková, Markéta; Bryja, Vítězslav; Umannová, Lenka; Bernatík, O.; Kozubík, Alois; Machala, M.; Vondráček, Jan

2011-01-01

Roč. 122, č. 2 (2011), s. 349-360 ISSN 1096-6080 R&D Projects: GA ČR(CZ) GD204/09/H058 Grant - others:GA ČR(CZ) GA524/09/1337 Program:GA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : dioxin * beta-catenin * AhR Subject RIV: BO - Biophysics Impact factor: 4.652, year: 2011

Fentanyl inhibits proliferation and invasion of colorectal cancer via β-catenin

Science.gov (United States)

Zhang, Xiu-Lai; Chen, Min-Li; Zhou, Sheng-Li

2015-01-01

Background and aim: Fentanyl is widely used for relieving pain and narcotizing in cancer patients. However, there are few published reports regarding the effects of fentanyl on tumor control and treatment. Here we investigated the effects of fentanyl on tumor growth and cell invasion in the human colorectal carcinoma (HCT116) cells. Methods: Nude mice xenografts of HCT116 cells were established to assess the inhibition effect on tumor growth by fentanyl. MTT and Transwell were employed to determine the cell survival rate and cell invasion, respectively. MicroRNAs and mRNAs expression were quantified by real-time PCR. β-catenin and matrix metalloproteinases (MMP-2 and MMP-9) expression were assayed by western blotting. β-Catenin-specific small interfering RNA (Si-β-catenin) and miR-182 mimics were transfected in cells to investigate the mechanism underlying the effects of fentanyl on the colorectal tumor and HCT116 cells. Results: Treatment with fentanyl inhibited the tumor growth and HCT116 cells invasion. Fentanyl also downregulated the expression of β-catenin and miR-182 in both xenograft tumors and HCT116 cells, and decreased the protein level of MMP-9 in HCT116 cells. Downregulation of β-Catenin resulted in the decrease of miR-182 expression in colorectal cells. In addition, the overexpression of miR-182 reversed the effect of fentanyl on MMP-9 expression and cell invasion of HCT116 cells. Conclusions: The current study demonstrated that the inhibition of tumor growth and cell invasion in colorectal cancer by fentanyl is probably due to downregulation of miR-182 and MMP-9 expression by β-catenin. PMID:25755709

Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/β-catenin signaling pathway in HCT116 cells

International Nuclear Information System (INIS)

Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju; Kim, Chul Young; Nho, Chu Won

2012-01-01

Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/β-catenin signaling pathway and the induction of G0/G1-phase arrest by gomisins J and N, derived from the fruits of S. chinensis, in HCT116 human colon cancer cells. Highlights: ► Gomisins J and N inhibited Wnt/β-catenin signaling pathway in HCT116 cells. ► Gomisins J and N disrupted the binding of β-catenin to specific DNA sequences, TBE. ► Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. ► Gomisins J and N inhibited the expression of Cyc D1, a Wnt/β-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/β-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/β-catenin signaling by disrupting the interaction between β-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the β-catenin protein. Gomisins J and N inhibit HCT116 cell proliferation by arresting the cell cycle at the G0/G1 phase. The G0/G1 phase arrest induced by gomisins J and N appears to be caused by a decrease in the expression of Cyclin D1, a representative target gene of the Wnt/β-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/β-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

Regulation of AR and (beta)-Catenin Signaling by Pin 1 in Prostate Cancer

National Research Council Canada - National Science Library

Chen, Shaoyong

2006-01-01

.... Another finding is that APC is expressed mainly in LNCaP nucleus and our preliminary results showed reduction of APC expression in LNCaP and PC3 cells leads to enhanced beta-catenin/Tcf4 activity.

Circadian rhythms, Wnt/beta-catenin pathway and PPAR alpha/gamma profiles in diseases with primary or secondary cardiac dysfunction

Directory of Open Access Journals (Sweden)

Yves eLecarpentier

2014-11-01

Full Text Available Circadian clock mechanisms are far-from-equilibrium dissipative structures. Peroxisome proliferator-activated receptors (PPAR alpha, beta/delta and gamma play a key role in metabolic regulatory processes, particularly in heart muscle. Links between circadian rhythms (CRs and PPARs have been established. Mammalian CRs involve at least two critical transcription factors, CLOCK and BMAL1 (Gekakis et al., 1998; Hogenesch et al., 1998. PPAR gamma plays a major role in both glucose and lipid metabolisms and presents circadian properties which coordinate the interplay between metabolism and CRs. PPAR gamma is a major component of the vascular clock. Vascular PPAR gamma is a peripheral regulator of cardiovascular rhythms controlling circadian variations in blood pressure and heart rate through BMAL1. We focused our review on diseases with abnormalities of CRs and with primary or secondary cardiac dysfunction. Moreover, these diseases presented changes in the Wnt/beta-catenin pathway and PPARs, according to two opposed profiles. Profile 1 was defined as follows: inactivation of the Wnt/beta-catenin pathway with increased expression of PPAR gamma. Profile 2 was defined as follows: activation of the Wnt/beta-catenin pathway with decreased expression of PPAR gamma. A typical profile 1 disease is arrhythmogenic right ventricular cardiomyopathy, a genetic cardiac disease which presents mutations of the desmosomal proteins and is mainly characterized by fatty acid accumulation in adult cardiomyocytes mainly in the right ventricle. The link between PPAR gamma dysfunction and desmosomal genetic mutations occurs via inactivation of the Wnt/beta-catenin pathway presenting oscillatory properties. A typical profile 2 disease is type 2 diabetes, with activation of the Wnt/beta-catenin pathway and decreased expression of PPAR gamma. CRs abnormalities are present in numerous pathologies such as cardiovascular diseases, sympathetic/parasympathetic dysfunction

Derricin and derricidin inhibit Wnt/β-catenin signaling and suppress colon cancer cell growth in vitro.

Directory of Open Access Journals (Sweden)

Barbara F Fonseca

Full Text Available Overactivation of the Wnt/β-catenin pathway in adult tissues has been implicated in many diseases, such as colorectal cancer. Finding chemical substances that can prevent this phenomenon is an emerging problem. Recently, several natural compounds have been described as Wnt/β-catenin inhibitors and might be promising agents for the control of carcinogenesis. Here, we describe two natural substances, derricin and derricidin, belonging to the chalcone subclass, that show potent transcriptional inhibition of the Wnt/β-catenin pathway. Both chalcones are able to affect the cell distribution of β-catenin, and inhibit Wnt-specific reporter activity in HCT116 cells and in Xenopus embryos. Derricin and derricidin also strongly inhibited canonical Wnt activity in vitro, and rescued the Wnt-induced double axis phenotype in Xenopus embryos. As a consequence of Wnt/β-catenin inhibition, derricin and derricidin treatments reduce cell viability and lead to cell cycle arrest in colorectal cancer cell lines. Taken together, our results strongly support these chalcones as novel negative modulators of the Wnt/β-catenin pathway and colon cancer cell growth in vitro.

Exogenous DKK-3/REIC inhibits Wnt/β-catenin signaling and cell proliferation in human kidney cancer KPK1.

Science.gov (United States)

Xu, Jiaqi; Sadahira, Takuya; Kinoshita, Rie; Li, Shun-Ai; Huang, Peng; Wada, Koichiro; Araki, Motoo; Ochiai, Kazuhiko; Noguchi, Hirofumi; Sakaguchi, Masakiyo; Nasu, Yasutomo; Watanabe, Masami

2017-11-01

The third member of the Dickkopf family (DKK-3), also known as reduced expression in immortalized cells (REIC), is a tumor suppressor present in a variety of tumor cells. Regarding the regulation of the Wnt/β-catenin signaling pathway, exogenous DKK-1 and DKK-2 are reported to inhibit Wnt signaling by binding the associated effectors. However, whether exogenous DKK-3 inhibits Wnt signaling remains unclear. A recombinant protein of human full-length DKK-3 was used to investigate the exogenous effects of the protein in vitro in KPK1 human renal cell carcinoma cells. It was demonstrated that the expression of phosphorylated (p-)β-catenin (inactive form as the transcriptional factor) was increased in KPK1 cells treated with the exogenous DKK-3 protein. The levels of non-p-β-catenin (activated form of β-catenin) were consistently decreased. It was revealed that the expression of transcription factor (TCF) 1 and c-Myc, the downstream transcription factors of the Wnt/β-catenin signaling pathway, was inhibited following treatment with DKK-3. A cancer cell viability assay confirmed the anti-proliferative effects of exogenous DKK-3 protein, which was consistent with a suppressed Wnt/β-catenin signaling cascade. In addition, as low-density lipoprotein receptor-related protein 6 (LRP6) is a receptor of DKK-1 and DKK-2 and their interaction on the cell surface inhibits Wnt/β-catenin signaling, it was examined whether the exogenous DKK-3 protein affects LRP6-mediated Wnt/β-catenin signaling. The LRP6 gene was silenced and the effects of DKK-3 on the time course of the upregulation of p-β-catenin expression were subsequently analyzed. Notably, LRP6 depletion elevated the base level of p-β-catenin; however, there was no significant effect on its upregulation course or expression pattern. These findings indicate that exogenous DKK-3 upregulates p-β-catenin and inhibits Wnt/β-catenin signaling in an LRP6-independent manner. Therefore, exogenous DKK-3 protein may inhibit

Catenins

DEFF Research Database (Denmark)

Perez-Moreno, Mirna; Fuchs, Elaine

2006-01-01

intercellular communication between different cell types within a tissue. These findings reveal novel aspects of AJ function in normal tissues and offer insights into how changes in AJs and their associated proteins and cytoskeletal dynamics impact wound-repair and cancer......., conventional views have similarly been shaken about the other two major AJ catenins, alpha-catenin and p120-catenin. Catenins have emerged as molecular sensors that integrate cell-cell junctions and cytoskeletal dynamics with signaling pathways that govern morphogenesis, tissue homeostasis, and even......Adherens junctions have been traditionally viewed as building blocks of tissue architecture. The foundations for this view began to change with the discovery that a central component of AJs, beta-catenin, can also function as a transcriptional cofactor in Wnt signaling. In recent years...

Inhibition of Chondrocyte Hypertrophy of Osteoarthritis by Disruptor Peptide

Science.gov (United States)

2017-07-01

with PTHR and inhibits the pathogenic beta-catenin- mediated PTHR signaling switch. In Aim 2, we will define the role of disruptor peptide in...confirmed that disruptor peptide conjugated to penetratin can enter cells. Importantly, disruptor peptide can reverse the beta-catenin- mediated PTH... mediated PTHR signaling switch in chondrocytes. Mouse primary chondrocytes express both β-catenin and PTHR. Our data showed that Pen-dis- pep

Neurotensin receptor 1 gene activation by the Tcf/beta-catenin pathway is an early event in human colonic adenomas.

Science.gov (United States)

Souazé, Frédérique; Viardot-Foucault, Véronique; Roullet, Nicolas; Toy-Miou-Leong, Mireille; Gompel, Anne; Bruyneel, Erik; Comperat, Eva; Faux, Maree C; Mareel, Marc; Rostène, William; Fléjou, Jean-François; Gespach, Christian; Forgez, Patricia

2006-04-01

Alterations in the Wnt/APC (adenomatous polyposis coli) signalling pathway, resulting in beta-catenin/T cell factor (Tcf)-dependent transcriptional gene activation, are frequently detected in familial and sporadic colon cancers. The neuropeptide neurotensin (NT) is widely distributed in the gastrointestinal tract. Its proliferative and survival effects are mediated by a G-protein coupled receptor, the NT1 receptor. NT1 receptor is not expressed in normal colon epithelial cells, but is over expressed in a number of cancer cells and tissues suggesting a link to the outgrowth of human colon cancer. Our results demonstrate that the upregulation of NT1 receptor occurring in colon cancer is the result of Wnt/APC signalling pathway activation. We first established the functionality of the Tcf response element within the NT1 receptor promoter. Consequently, we observed the activation of NT1 receptor gene by agents causing beta-catenin cytosolic accumulation, as well as a strong decline of endogenous receptor when wt-APC was restored. At the cellular level, the re-establishment of wt-APC phenotype resulted in the impaired functionality of NT1 receptor, like the breakdown in NT-induced intracellular calcium mobilization and the loss of NT pro-invasive effect. We corroborated the Wnt/APC signalling pathway on the NT1 receptor promoter activation with human colon carcinogenesis, and showed that NT1 receptor gene activation was perfectly correlated with nuclear or cytoplasmic beta-catenin localization while NT1 receptor was absent when beta-catenin was localized at the cell-cell junction in early adenomas of patients with familial adenomatous polyposis, hereditary non-polyposis colorectal cancer and loss of heterozygosity tumours. In this report we establish a novel link in vitro between the Tcf/beta-catenin pathway and NT1 receptor promoter activation.

Therapeutic effects of antibiotic drug tigecycline against cervical squamous cell carcinoma by inhibiting Wnt/β-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Li, Hui; Jiao, Shun [Department of Obstetrics and Gynaecology, JingZhou Hospital Affiliated to Huazhong University of Science and Technology, Jingzhou (China); Li, Xin [Department of Obstetrics and Gynaecology, RenMin Hospital of Wuhan University, Wuhan (China); Banu, Hasina; Hamal, Shreejana [Department of Clinical Medicine, Medical School of Yangtze University, Jingzhou (China); Wang, Xianrong, E-mail: Dr.XianRong.Wang@hotmail.com [Department of Obstetrics and Gynaecology, JingZhou Hospital Affiliated to Huazhong University of Science and Technology, Jingzhou (China)

2015-11-06

Aberrant activation of the Wnt/β-catenin signaling pathway is common in human cervical cancers and has great potential therapeutic value. We show that tigecycline, a FDA-approved antibiotic drug, targets cervical squamous cell carcinoma through inhibiting Wnt/β-catenin signaling pathway. Tigecycline is effective in inducing apoptosis, inhibiting proliferation and anchorage-independent colony formation of Hela cells. The inhibitory effects of tigecycline are further enhanced upon combination with paclitaxel, a most commonly used chemotherapeutic drug for cervical cancer. In a cervical xenograft model, tigecycline inhibits tumor growth as a single agent and its combination with paclitaxel significantly inhibits more tumor growth throughout the duration of treatment. We further show that tigecycline decreases level of both cytoplasmic and nuclear β-catenin and suppressed Wnt/β-catenin-mediated transcription through increasing levels of Axin 1 in Hela cells. In addition, stabilization or overexpression of β-catenin using pharmacological and genetic approaches abolished the effects of tigecycline in inhibiting proliferation and inducing apoptosis of Hela cells. Our study suggests that tigecycline is a useful addition to the treatment armamentarium for cervical cancer and targeting Wnt/β-catenin represents a potential therapeutic strategy in cervical cancer. - Highlights: • We repurposed the antibiotic drug tigecycline for cervical cancer treatment. • Tigecycline is effectively against cervical cancer cells in vitro and in vivo. • Combination of tigecycline and paclitaxel is synergistic in targeting Hela cells. • Tigecycline acts on Hela cells through inhibiting Wnt/β-catenin signaling.

Therapeutic effects of antibiotic drug tigecycline against cervical squamous cell carcinoma by inhibiting Wnt/β-catenin signaling

International Nuclear Information System (INIS)

Li, Hui; Jiao, Shun; Li, Xin; Banu, Hasina; Hamal, Shreejana; Wang, Xianrong

2015-01-01

Aberrant activation of the Wnt/β-catenin signaling pathway is common in human cervical cancers and has great potential therapeutic value. We show that tigecycline, a FDA-approved antibiotic drug, targets cervical squamous cell carcinoma through inhibiting Wnt/β-catenin signaling pathway. Tigecycline is effective in inducing apoptosis, inhibiting proliferation and anchorage-independent colony formation of Hela cells. The inhibitory effects of tigecycline are further enhanced upon combination with paclitaxel, a most commonly used chemotherapeutic drug for cervical cancer. In a cervical xenograft model, tigecycline inhibits tumor growth as a single agent and its combination with paclitaxel significantly inhibits more tumor growth throughout the duration of treatment. We further show that tigecycline decreases level of both cytoplasmic and nuclear β-catenin and suppressed Wnt/β-catenin-mediated transcription through increasing levels of Axin 1 in Hela cells. In addition, stabilization or overexpression of β-catenin using pharmacological and genetic approaches abolished the effects of tigecycline in inhibiting proliferation and inducing apoptosis of Hela cells. Our study suggests that tigecycline is a useful addition to the treatment armamentarium for cervical cancer and targeting Wnt/β-catenin represents a potential therapeutic strategy in cervical cancer. - Highlights: • We repurposed the antibiotic drug tigecycline for cervical cancer treatment. • Tigecycline is effectively against cervical cancer cells in vitro and in vivo. • Combination of tigecycline and paclitaxel is synergistic in targeting Hela cells. • Tigecycline acts on Hela cells through inhibiting Wnt/β-catenin signaling.

Brain Metastases from Lung Cancer Show Increased Expression of DVL1, DVL3 and Beta-Catenin and Down-Regulation of E-Cadherin

Directory of Open Access Journals (Sweden)

Anja Kafka

2014-06-01

Full Text Available The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1, Dishevelled-3 (DVL3, E-cadherin (CDH1 and beta-catenin (CTNNB1. Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR/loss of heterozygosity (LOH. Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p = 0.0001. Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC were significantly associated to CDH1 LOH (p = 0.001. Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.

MENA is a transcriptional target of the Wnt/beta-catenin pathway.

Directory of Open Access Journals (Sweden)

Ayaz Najafov

Full Text Available Wnt/β-catenin signalling pathway plays important roles in embryonic development and carcinogenesis. Overactivation of the pathway is one of the most common driving forces in major cancers such as colorectal and breast cancers. The downstream effectors of the pathway and its regulation of carcinogenesis and metastasis are still not very well understood. In this study, which was based on two genome-wide transcriptomics screens, we identify MENA (ENAH, Mammalian enabled homologue as a novel transcriptional target of the Wnt/β-catenin signalling pathway. We show that the expression of MENA is upregulated upon overexpression of degradation-resistant β-catenin. Promoters of all mammalian MENA homologues contain putative binding sites for Tcf4 transcription factor--the primary effector of the Wnt/β-catenin pathway and we demonstrate functionality of these Tcf4-binding sites using luciferase reporter assays and overexpression of β-catenin, Tcf4 and dominant-negative Tcf4. In addition, lithium chloride-mediated inhibition of GSK3β also resulted in increase in MENA mRNA levels. Chromatin immunoprecipitation showed direct interaction between β-catenin and MENA promoter in Huh7 and HEK293 cells and also in mouse brain and liver tissues. Moreover, overexpression of Wnt1 and Wnt3a ligands increased MENA mRNA levels. Additionally, knock-down of MENA ortholog in D. melanogaster eyeful and sensitized eye cancer fly models resulted in increased tumor and metastasis formations. In summary, our study identifies MENA as novel nexus for the Wnt/β-catenin and the Notch signalling cascades.

MENA is a transcriptional target of the Wnt/beta-catenin pathway.

Science.gov (United States)

Najafov, Ayaz; Seker, Tuncay; Even, Ipek; Hoxhaj, Gerta; Selvi, Osman; Ozel, Duygu Esen; Koman, Ahmet; Birgül-İyison, Necla

2012-01-01

Wnt/β-catenin signalling pathway plays important roles in embryonic development and carcinogenesis. Overactivation of the pathway is one of the most common driving forces in major cancers such as colorectal and breast cancers. The downstream effectors of the pathway and its regulation of carcinogenesis and metastasis are still not very well understood. In this study, which was based on two genome-wide transcriptomics screens, we identify MENA (ENAH, Mammalian enabled homologue) as a novel transcriptional target of the Wnt/β-catenin signalling pathway. We show that the expression of MENA is upregulated upon overexpression of degradation-resistant β-catenin. Promoters of all mammalian MENA homologues contain putative binding sites for Tcf4 transcription factor--the primary effector of the Wnt/β-catenin pathway and we demonstrate functionality of these Tcf4-binding sites using luciferase reporter assays and overexpression of β-catenin, Tcf4 and dominant-negative Tcf4. In addition, lithium chloride-mediated inhibition of GSK3β also resulted in increase in MENA mRNA levels. Chromatin immunoprecipitation showed direct interaction between β-catenin and MENA promoter in Huh7 and HEK293 cells and also in mouse brain and liver tissues. Moreover, overexpression of Wnt1 and Wnt3a ligands increased MENA mRNA levels. Additionally, knock-down of MENA ortholog in D. melanogaster eyeful and sensitized eye cancer fly models resulted in increased tumor and metastasis formations. In summary, our study identifies MENA as novel nexus for the Wnt/β-catenin and the Notch signalling cascades.

BMP signaling inhibits intestinal stem cell self-renewal through suppression of Wnt-beta-catenin signaling.

Science.gov (United States)

He, Xi C; Zhang, Jiwang; Tong, Wei-Gang; Tawfik, Ossama; Ross, Jason; Scoville, David H; Tian, Qiang; Zeng, Xin; He, Xi; Wiedemann, Leanne M; Mishina, Yuji; Li, Linheng

2004-10-01

In humans, mutations in BMPR1A, SMAD4 and PTEN are responsible for juvenile polyposis syndrome, juvenile intestinal polyposis and Cowden disease, respectively. The development of polyposis is a common feature of these diseases, suggesting that there is an association between BMP and PTEN pathways. The mechanistic link between BMP and PTEN pathways and the related etiology of juvenile polyposis is unresolved. Here we show that conditional inactivation of Bmpr1a in mice disturbs homeostasis of intestinal epithelial regeneration with an expansion of the stem and progenitor cell populations, eventually leading to intestinal polyposis resembling human juvenile polyposis syndrome. We show that BMP signaling suppresses Wnt signaling to ensure a balanced control of stem cell self-renewal. Mechanistically, PTEN, through phosphatidylinosital-3 kinase-Akt, mediates the convergence of the BMP and Wnt pathways on control of beta-catenin. Thus, BMP signaling may control the duplication of intestinal stem cells, thereby preventing crypt fission and the subsequent increase in crypt number.

RAC1 GTP-ase signals Wnt-beta-catenin pathway mediated integrin-directed metastasis-associated tumor cell phenotypes in triple negative breast cancers.

Science.gov (United States)

De, Pradip; Carlson, Jennifer H; Jepperson, Tyler; Willis, Scooter; Leyland-Jones, Brian; Dey, Nandini

2017-01-10

The acquisition of integrin-directed metastasis-associated (ID-MA) phenotypes by Triple-Negative Breast Cancer (TNBC) cells is caused by an upregulation of the Wnt-beta-catenin pathway (WP). We reported that WP is one of the salient genetic features of TNBC. RAC-GTPases, small G-proteins which transduce signals from cell surface proteins including integrins, have been implicated in tumorigenesis and metastasis by their role in essential cellular functions like motility. The collective percentage of alteration(s) in RAC1 in ER+ve BC was lower as compared to ER-ve BC (35% vs 57%) (brca/tcga/pub2015). High expression of RAC1 was associated with poor outcome for RFS with HR=1.48 [CI: 1.15-1.9] p=0.0019 in the Hungarian ER-veBC cohort. Here we examined how WP signals are transduced via RAC1 in the context of ID-MA phenotypes in TNBC. Using pharmacological agents (sulindac sulfide), genetic tools (beta-catenin siRNA), WP modulators (Wnt-C59, XAV939), RAC1 inhibitors (NSC23766, W56) and WP stimulations (LWnt3ACM, Wnt3A recombinant) in a panel of 6-7 TNBC cell lines, we studied fibronectin-directed (1) migration, (2) matrigel invasion, (3) RAC1 and Cdc42 activation, (4) actin dynamics (confocal microscopy) and (5) podia-parameters. An attenuation of WP, which (a) decreased cellular levels of beta-catenin, as well as its nuclear active-form, (b) decreased fibronectin-induced migration, (c) decreased invasion, (d) altered actin dynamics and (e) decreased podia-parameters was successful in blocking fibronectin-mediated RAC1/Cdc42 activity. Both Wnt-antagonists and RAC1 inhibitors blocked fibronectin-induced RAC1 activation and inhibited the fibronectin-induced ID-MA phenotypes following specific WP stimulation by LWnt3ACM as well as Wnt3A recombinant protein. To test a direct involvement of RAC1-activation in WP-mediated ID-MA phenotypes, we stimulated brain-metastasis specific MDA-MB231BR cells with LWnt3ACM. LWnt3ACM-stimulated fibronectin-directed migration was blocked by

Sequential Activation and Inactivation of Dishevelled in the Wnt/beta-Catenin Pathway by Casein Kinases

Czech Academy of Sciences Publication Activity Database

Bernatík, Ondřej; Ganji, R.S.; Dijksterhuis, J.; Koník, P.; Červenka, I.; Krejčí, Pavel; Schulte, G.; Bryja, Vítězslav

2011-01-01

Roč. 286, č. 12 (2011), s. 10396-10410 ISSN 0021-9258 Institutional support: RVO:68081707 Keywords : WNT SIGNAL-TRANSDUCTION * BETA-CATENIN * I-EPSILON Subject RIV: BO - Biophysics Impact factor: 4.773, year: 2011

Inhibition of disheveled-2 resensitizes cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Luo, Ke; Gu, Xiuhui [School of Basic Medical Sciences, Chengdu Medical College, Chengdu (China); Liu, Jing; Zeng, Guodan; Peng, Liaotian; Huang, Houyi; Jiang, Mengju [School of Biomedical Sciences, Chengdu Medical College, Chengdu (China); Yang, Ping; Li, Minhui [School of Basic Medical Sciences, Chengdu Medical College, Chengdu (China); Yang, Yuhan; Wang, Yuanyuan [School of Biomedical Sciences, Chengdu Medical College, Chengdu (China); Peng, Quekun, E-mail: pengquekun@163.com [School of Biomedical Sciences, Chengdu Medical College, Chengdu (China); Zhu, Li, E-mail: 1968403299@qq.com [Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital, Chengdu Medical College, Chengdu (China); Zhang, Kun, E-mail: zhangkunyyo@163.com [School of Biomedical Sciences, Chengdu Medical College, Chengdu (China)

2016-09-10

Cisplatin (CDDP) is currently recommended as the front-line chemotherapeutic agent for lung cancer. However, the resistance to cisplatin is widespread in patients with advanced lung cancer, and the molecular mechanism of such resistance remains incompletely understood. Disheveled (DVL), a key mediator of Wnt/β-catenin, has been linked to cancer progression, while the role of DVL in cancer drug resistance is not clear. Here, we found that DVL2 was over-expressed in cisplatin-resistant human lung cancer cells A549/CDDP compared to the parental A549 cells. Inhibition of DVL2 by its inhibitor (3289-8625) or shDVL2 resensitized A549/CDDP cells to cisplatin. In addition, over-expression of DVL2 in A549 cells increased the protein levels of BCRP, MRP4, and Survivin, which are known to be associated with chemoresistance, while inhibition of DVL2 in A549/CDDP cells decreased these protein levels, and reduced the accumulation and nuclear translocation of β-catenin. In addition, shβ-catenin abolished the DVL2-induced the expression of BCRP, MRP4, and Survivin. Furthermore, our data showed that GSK3β/β-catenin signals were aberrantly activated by DVL2, and inactivation of GSK3β reversed the shDVL2-induced down-regulation of β-catenin. Taken together, these results suggested that inhibition of DVL2 can sensitize cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling and inhibiting BCRP, MRP4, and Survivin expression. It promises a new strategy to chemosensitize cisplatin-induced cytotoxicity in lung cancer. - Highlights: • Inhibition of DVL2 chemosensitizes resistant lung cancer to cisplatin. • DVL2 positively regulated the expression of BCRP, MRP4 and Survivin. • β-catenin mediated the DVL2-induced expression. • DVL2 increased the accumulation and nuclear translocation of β-catenin. • DVL2 up-regulated β-catenin via inhibiting GSK3β.

Inhibition of disheveled-2 resensitizes cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling

International Nuclear Information System (INIS)

Luo, Ke; Gu, Xiuhui; Liu, Jing; Zeng, Guodan; Peng, Liaotian; Huang, Houyi; Jiang, Mengju; Yang, Ping; Li, Minhui; Yang, Yuhan; Wang, Yuanyuan; Peng, Quekun; Zhu, Li; Zhang, Kun

2016-01-01

Cisplatin (CDDP) is currently recommended as the front-line chemotherapeutic agent for lung cancer. However, the resistance to cisplatin is widespread in patients with advanced lung cancer, and the molecular mechanism of such resistance remains incompletely understood. Disheveled (DVL), a key mediator of Wnt/β-catenin, has been linked to cancer progression, while the role of DVL in cancer drug resistance is not clear. Here, we found that DVL2 was over-expressed in cisplatin-resistant human lung cancer cells A549/CDDP compared to the parental A549 cells. Inhibition of DVL2 by its inhibitor (3289-8625) or shDVL2 resensitized A549/CDDP cells to cisplatin. In addition, over-expression of DVL2 in A549 cells increased the protein levels of BCRP, MRP4, and Survivin, which are known to be associated with chemoresistance, while inhibition of DVL2 in A549/CDDP cells decreased these protein levels, and reduced the accumulation and nuclear translocation of β-catenin. In addition, shβ-catenin abolished the DVL2-induced the expression of BCRP, MRP4, and Survivin. Furthermore, our data showed that GSK3β/β-catenin signals were aberrantly activated by DVL2, and inactivation of GSK3β reversed the shDVL2-induced down-regulation of β-catenin. Taken together, these results suggested that inhibition of DVL2 can sensitize cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling and inhibiting BCRP, MRP4, and Survivin expression. It promises a new strategy to chemosensitize cisplatin-induced cytotoxicity in lung cancer. - Highlights: • Inhibition of DVL2 chemosensitizes resistant lung cancer to cisplatin. • DVL2 positively regulated the expression of BCRP, MRP4 and Survivin. • β-catenin mediated the DVL2-induced expression. • DVL2 increased the accumulation and nuclear translocation of β-catenin. • DVL2 up-regulated β-catenin via inhibiting GSK3β.

Regulation of slow and fast muscle myofibrillogenesis by Wnt/beta-catenin and myostatin signaling.

NARCIS (Netherlands)

Tee, J.M.; van Rooijen, C.R.; Boonen, R.A.C.M.; Zivkovic, D.

2009-01-01

Deviation from proper muscle development or homeostasis results in various myopathic conditions. Employing genetic as well as chemical intervention, we provide evidence that a tight regulation of Wnt/beta-catenin signaling is essential for muscle fiber growth and maintenance. In zebrafish embryos,

Fluoxetine ameliorates cartilage degradation in osteoarthritis by inhibiting Wnt/β-catenin signaling.

Science.gov (United States)

Miyamoto, Kentaro; Ohkawara, Bisei; Ito, Mikako; Masuda, Akio; Hirakawa, Akihiro; Sakai, Tadahiro; Hiraiwa, Hideki; Hamada, Takashi; Ishiguro, Naoki; Ohno, Kinji

2017-01-01

Abnormal activation of the Wnt/β-catenin signaling is implicated in the osteoarthritis (OA) pathology. We searched for a pre-approved drug that suppresses abnormally activated Wnt/β-catenin signaling and has a potency to reduce joint pathology in OA. We introduced the TOPFlash reporter plasmid into HCS-2/8 human chondrosarcoma cells to estimate the Wnt/β-catenin activity in the presence of 10 μM each compound in a panel of pre-approved drugs. We found that fluoxetine, an antidepressant in the class of selective serotonin reuptake inhibitors (SSRI), down-regulated Wnt/β-catenin signaling in human chondrosarcoma cells. Fluoxetine inhibited both Wnt3A- and LiCl-induced loss of proteoglycans in chondrogenically differentiated ATDC5 cells. Fluoxetine increased expression of Sox9 (the chondrogenic master regulator), and decreased expressions of Axin2 (a marker for Wnt/β-catenin signaling) and Mmp13 (matrix metalloproteinase 13). Fluoxetine suppressed a LiCl-induced increase of total β-catenin and a LiCl-induced decrease of phosphorylated β-catenin in a dose-dependent manner. An in vitro protein-binding assay showed that fluoxetine enhanced binding of β-catenin with Axin1, which is a scaffold protein forming the degradation complex for β-catenin. Fluoxetine suppressed LiCl-induced β-catenin accumulation in human OA chondrocytes. Intraarticular injection of fluoxetine in a rat OA model ameliorated OA progression and suppressed β-catenin accumulation.

Fluoxetine ameliorates cartilage degradation in osteoarthritis by inhibiting Wnt/β-catenin signaling.

Directory of Open Access Journals (Sweden)

Kentaro Miyamoto

Full Text Available Abnormal activation of the Wnt/β-catenin signaling is implicated in the osteoarthritis (OA pathology. We searched for a pre-approved drug that suppresses abnormally activated Wnt/β-catenin signaling and has a potency to reduce joint pathology in OA. We introduced the TOPFlash reporter plasmid into HCS-2/8 human chondrosarcoma cells to estimate the Wnt/β-catenin activity in the presence of 10 μM each compound in a panel of pre-approved drugs. We found that fluoxetine, an antidepressant in the class of selective serotonin reuptake inhibitors (SSRI, down-regulated Wnt/β-catenin signaling in human chondrosarcoma cells. Fluoxetine inhibited both Wnt3A- and LiCl-induced loss of proteoglycans in chondrogenically differentiated ATDC5 cells. Fluoxetine increased expression of Sox9 (the chondrogenic master regulator, and decreased expressions of Axin2 (a marker for Wnt/β-catenin signaling and Mmp13 (matrix metalloproteinase 13. Fluoxetine suppressed a LiCl-induced increase of total β-catenin and a LiCl-induced decrease of phosphorylated β-catenin in a dose-dependent manner. An in vitro protein-binding assay showed that fluoxetine enhanced binding of β-catenin with Axin1, which is a scaffold protein forming the degradation complex for β-catenin. Fluoxetine suppressed LiCl-induced β-catenin accumulation in human OA chondrocytes. Intraarticular injection of fluoxetine in a rat OA model ameliorated OA progression and suppressed β-catenin accumulation.

[Expression of ICAT and Wnt signaling-related proteins in the monocytic differentiation of HL-60 cells induced by a new steroidal drug NSC67657].

Science.gov (United States)

Wang, J S; Wang, W J; Wang, T; Zhang, Y

2016-04-01

To investigate the expression of mRNA and proteins of β-catenin, TCF-4 (ICAT) and Wnt signaling pathway-related genes in the monocytic differentiation of acute myeloid leukemia HL-60 cells induced by a new steroidal drug NSC67657. Wright's staining and α-NBE staining were used to observe the differentiation of HL-60 cells after 5 days of 10 μmol/L NSC67657 treatment. Flow cytometry (FCM) was used to detect the differentiation and cell cycles. The expressions of mRNA and proteins of ICAT and Wnt signaling pathway-related factors, including β-catenin, TCF-4, c-myc, cyclin D1 and TCF-1 before and after differentiation, were detected by RT-PCR and Western blot. Morphological observation showed that NSC67657 induced monocytic differentiation of HL-60 cells. At 5 days after 10 μmol/L NSC67657 treatment, the number of CD14(+) HL-60 cells was (94.37±2.84)%, significantly higher than the (1.31±0.09)% in control group (Pcells were of (18.76±0.98)%, significantly lower than that of (34.38±2.61) % in the control group (Pprotein, and down-regulated the expression of β-catenin mRNA and protin (Pprotein and nuclear protein in the HL-60 cells (P>0.05 for all). The target genes of Wnt signaling pathway, including c-myc, cyclinD1 and TCF-1 mRNA and proteins in the HL-60 cells were significantly down-regulated after NSC67657 treatment (Pcells, and down-regulates the expression of β-catenin and target genes of Wnt signaling pathway. These results indicate that Wnt signaling pathway may be directly or indirectly involved in the monocytic differentiation process of HL-60 cells.

ICAT and the NASA technology transfer process

Science.gov (United States)

Rifkin, Noah; Tencate, Hans; Watkins, Alison

1993-01-01

This paper will address issues related to NASA's technology transfer process and will cite the example of using ICAT technologies in educational tools. The obstacles to effective technology transfer will be highlighted, viewing the difficulties in achieving successful transfers of ICAT technologies.

Role for beta-catenin and HOX transcription factors in Caenorhabditis elegans and mammalian host epithelial-pathogen interactions.

Science.gov (United States)

Irazoqui, Javier E; Ng, Aylwin; Xavier, Ramnik J; Ausubel, Frederick M

2008-11-11

We used the model nematode Caenorhabditis elegans infected with the human pathogen Staphylococcus aureus to identify components of epithelial immunity. Transcriptional profiling and reverse genetic analysis revealed that mutation of the C. elegans beta-catenin homolog bar-1 or the downstream homeobox gene egl-5 results in a defective response and hypersensitivity to S. aureus infection. Epistasis analysis showed that bar-1 and egl-5 function in parallel to previously described C. elegans immune-response pathways. Overexpression of human homologs of egl-5 modulated NF-kappaB-dependent TLR2 signaling in epithelial cells. These data suggest that beta-catenin and homeobox genes play an important and conserved role in innate immune defense.

Wnt/beta-Catenin Signaling and Small Molecule Inhibitors

Science.gov (United States)

Voronkov, Andrey; Krauss, Stefan

2012-01-01

Wnt/β-catenin signaling is a branch of a functional network that dates back to the first metazoans and it is involved in a broad range of biological systems including stem cells, embryonic development and adult organs. Deregulation of components involved in Wnt/β-catenin signaling has been implicated in a wide spectrum of diseases including a number of cancers and degenerative diseases. The key mediator of Wnt signaling, β-catenin, serves several cellular functions. It functions in a dynamic mode at multiple cellular locations, including the plasma membrane, where β-catenin contributes to the stabilization of intercellular adhesive complexes, the cytoplasm where β-catenin levels are regulated and the nucleus where β-catenin is involved in transcriptional regulation and chromatin interactions. Central effectors of β-catenin levels are a family of cysteine-rich secreted glycoproteins, known as Wnt morphogens. Through the LRP5/6-Frizzled receptor complex, Wnts regulate the location and activity of the destruction complex and consequently intracellular β- catenin levels. However, β-catenin levels and their effects on transcriptional programs are also influenced by multiple other factors including hypoxia, inflammation, hepatocyte growth factor-mediated signaling, and the cell adhesion molecule E-cadherin. The broad implications of Wnt/β-catenin signaling in development, in the adult body and in disease render the pathway a prime target for pharmacological research and development. The intricate regulation of β-catenin at its various locations provides alternative points for therapeutic interventions. PMID:23016862

Abnormal lens morphogenesis and ectopic lens formation in the absence of beta-catenin function

Czech Academy of Sciences Publication Activity Database

Krešlová, Jana; Machoň, Ondřej; Růžičková, Jana; Láchová, Jitka; Wawrousek, E.F.; Kemler, R.; Krauss, S.; Piatigorsky, J.; Kozmik, Zbyněk

2007-01-01

Roč. 45, č. 4 (2007), s. 157-168 ISSN 1526-954X R&D Projects: GA ČR GA204/04/1358 Institutional research plan: CEZ:AV0Z50520514 Keywords : Wnt * beta-catenin * gene * lens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.516, year: 2007

MMTV-Wnt1 and -DeltaN89beta-catenin induce canonical signaling in distinct progenitors and differentially activate Hedgehog signaling within mammary tumors.

Directory of Open Access Journals (Sweden)

Brigitte Teissedre

Full Text Available Canonical Wnt/beta-catenin signaling regulates stem/progenitor cells and, when perturbed, induces many human cancers. A significant proportion of human breast cancer is associated with loss of secreted Wnt antagonists and mice expressing MMTV-Wnt1 and MMTV-DeltaN89beta-catenin develop mammary adenocarcinomas. Many studies have assumed these mouse models of breast cancer to be equivalent. Here we show that MMTV-Wnt1 and MMTV-DeltaN89beta-catenin transgenes induce tumors with different phenotypes. Using axin2/conductin reporter genes we show that MMTV-Wnt1 and MMTV-DeltaN89beta-catenin activate canonical Wnt signaling within distinct cell-types. DeltaN89beta-catenin activated signaling within a luminal subpopulation scattered along ducts that exhibited a K18(+ER(-PR(-CD24(highCD49f(low profile and progenitor properties. In contrast, MMTV-Wnt1 induced canonical signaling in K14(+ basal cells with CD24/CD49f profiles characteristic of two distinct stem/progenitor cell-types. MMTV-Wnt1 produced additional profound effects on multiple cell-types that correlated with focal activation of the Hedgehog pathway. We document that large melanocytic nevi are a hitherto unreported hallmark of early hyperplastic Wnt1 glands. These nevi formed along the primary mammary ducts and were associated with Hedgehog pathway activity within a subset of melanocytes and surrounding stroma. Hh pathway activity also occurred within tumor-associated stromal and K14(+/p63(+ subpopulations in a manner correlated with Wnt1 tumor onset. These data show MMTV-Wnt1 and MMTV-DeltaN89beta-catenin induce canonical signaling in distinct progenitors and that Hedgehog pathway activation is linked to melanocytic nevi and mammary tumor onset arising from excess Wnt1 ligand. They further suggest that Hedgehog pathway activation maybe a critical component and useful indicator of breast tumors arising from unopposed Wnt1 ligand.

NO-donating aspirin inhibits the growth of leukemic Jurkat cells and modulates β-catenin expression

International Nuclear Information System (INIS)

Nath, Niharika; Labaze, Georges; Rigas, Basil; Kashfi, Khosrow

2004-01-01

β-Catenin has been implicated in leukemic cell proliferation. We compared the effects of aspirin (ASA) and the ortho, meta, and para positional isomers of NO-donating aspirin (NO-ASA) on cell growth and β-catenin expression in human Jurkat T leukemic cells. Cell growth inhibition was strong: IC 50 for p-, o-, and m- were 20 ± 1.6 (mean ± SEM), 15 ± 1.5, and 200 ± 12 μM, respectively, in contrast to that of ASA (3200 ± 375 μM). The para isomer of NO-ASA degraded β-catenin in a dose- and time-dependent manner coinciding with increasing expression of activated caspase-3. The caspase inhibitor ZVAD blocked β-catenin cleavage by p-NO-ASA and partially reversed cell growth inhibition by p-NO-ASA but not that by ASA. A denitrated analog of p-NO-ASA did not degrade β-catenin indicating the importance of the NO-donating moiety. Our findings suggest that NO-ASA merits further study as an agent against leukemia

Expression of beta-catenin, COX-2 and iNOS in colorectal cancer: relevance of COX-2 adn iNOS inhibitors for treatment in Malaysia.

Science.gov (United States)

Hong, Seok Kwan; Gul, Yunus A; Ithnin, Hairuszah; Talib, Arni; Seow, Heng Fong

2004-01-01

Promising new pharmacological agents and gene therapy targeting cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) could modulate treatment of colorectal cancer in the future. The aim of this study was to elucidate the expression fo beta-catenin and teh presence of COX-2 and iNOS in colorectal cancer specimens in Malaysia. This is a useful prelude to future studies investigating interventions directed towards COX-2 adn iNOS. A cross-section study using retrospective data over a 2-year period (1999-2000) involved 101 archival, formalin-fixed, paraffin-embedded tissue samples of colorectal cancers that were surgically resected in a tertiary referral. COX-2 production was detected in adjacent normal tissue in 34 sample (33.7%) and in tumour tissue in 60 samples (59.4%). More tumours expressed iNOS (82/101, 81.2%) than COX-2. No iNOS expression was detected in adjacent normal tissue. Intense beta-catenin immunoreactivity at the cell-to-cell border. Poorly differentiated tumours had significantly lower total beta-catenin (p = 0.009) and COX-2 scores (p = 0.031). No significant relationships were established between pathological stage and beta-catenin, COX-2 and iNOS scores. the accumulation of beta-catenin does not seem to be sufficient to activate pathways that lead to increased COX-2 and iNOS expression. A high proportion of colorectal cancers were found to express COX-2 and a significant number produced iNOS, suggesting that their inhibitors may be potentially useful as chemotherapeutic agents in the management of colorectal cancer.

Curcumin inhibits bladder cancer progression via regulation of β-catenin expression.

Science.gov (United States)

Shi, Jing; Wang, Yunpeng; Jia, Zhuomin; Gao, Yu; Zhao, Chaofei; Yao, Yuanxin

2017-07-01

Bladder cancer has a considerable morbidity and mortality impact with particularly poor prognosis. Curcumin has been recently noticed as a polyphenolic compound separated from turmeric to regulate tumor progression. However, the precise molecular mechanism by which curcumin inhibits the invasion and metastasis of bladder cancer cells is not fully elucidated. In this study, we investigate the effect of curcumin on the bladder cancer as well as possible mechanisms of curcumin. The expression of β-catenin was detected by quantitative real-time polymerase chain reaction and immunohistochemical analysis in a series of bladder cancer tissues. In addition, bladder cancer cell lines T24 and 5637 cells were treated with different concentrations of curcumin. The cytotoxic effect of curcumin on cell proliferation of T24 and 5637 cells was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The migration and invasion capacity of T24 and 5637 cells were measured by transwell assay. The effects of curcumin on expression levels of β-catenin and epithelial-mesenchymal transition marker were determined by western blotting. The β-catenin expression was significantly upregulated in bladder cancer tissues when compared with corresponding peri-tumor tissues. Furthermore, curcumin inhibited the cell proliferation of T24 and 5637 cells, and curcumin reduced the migration and invasive ability of T24 and 5637 cells via regulating β-catenin expression and reversing epithelial-mesenchymal transition. Curcumin may be a new drug for bladder cancer.

Germline genetic variants in the Wnt/beta-catenin pathway as predictors of colorectal cancer risk

Science.gov (United States)

Hildebrandt, Michelle A.T.; Reyes, Monica E.; Lin, Moubin; He, Yonggang; Nguyen, Son V.; Hawk, Ernest T.; Wu, Xifeng

2016-01-01

Background The Wnt/beta-catenin signaling pathway plays a key role in stem cell maintenance in the colorectum. Rare high penetrance genetic mutations in components of this pathway result in familial colorectal cancer, yet the impact of common, germline variants remains unknown. Methods We assessed 172 variants in 26 genes from the Wnt/beta-catenin pathway in 809 CRC cases and 814 healthy controls, followed by replication of the top findings in another 691 cases and 775 controls. In silico informatic tools were used to predict functional effects of variants. Results Eighteen SNPs in the pathway were significantly associated with CRC risk (P <0.05) in the discovery phase. We observed a significant dose-response increase in CRC risk by number of risk genotypes carried (P = 4.19 × 10−8). Gene-based analysis implicated CSNK1D (P = 0.014), FZD3 (P = 0.023), and APC (P = 0.027) as significant for CRC risk. In the replication phase, FZD3:rs11775139 remained significantly associated with reduced risk with a pooled OR of 0.85 (95% CI: 0.76–0.94, P = 0.001). Although borderline significant in the replication population, APC:rs2545162 was highly significant in the pooled analysis - OR: 1.42, 95% CI: 1.16–1.74, P =0.00085. Functional assessment identified several potential biological mechanisms underlying these associations. Conclusions Our findings suggest that common germline variants in the Wnt/beta-catenin pathway maybe involved in CRC development. Impact These variants may be informative in CRC risk assessment to identify individuals at increased risk who would be candidates for screening. PMID:26809274

Gaze Behavior, Believability, Likability and the iCat

NARCIS (Netherlands)

Poel, Mannes; Heylen, Dirk K.J.; Meulemans, M.; Nijholt, Antinus; Stock, O.; Nishida, T.

2007-01-01

The iCat is a user-interface robot with the ability to express a range of emotions through its facial features. This paper summarizes our research whether we can increase the believability and likability of the iCat for its human partners through the application of gaze behaviour. Gaze behaviour

Gaze Behavior, Believability, Likability and the iCat

NARCIS (Netherlands)

Nijholt, Antinus; Poel, Mannes; Heylen, Dirk K.J.; Stock, O.; Nishida, T.; Meulemans, M.; van Bremen, A.

2009-01-01

The iCat is a user-interface robot with the ability to express a range of emotions through its facial features. This paper summarizes our research whether we can increase the believability and likability of the iCat for its human partners through the application of gaze behaviour. Gaze behaviour

Magnesium Inhibits Wnt/β-Catenin Activity and Reverses the Osteogenic Transformation of Vascular Smooth Muscle Cells

Science.gov (United States)

Montes de Oca, Addy; Guerrero, Fatima; Martinez-Moreno, Julio M.; Madueño, Juan A.; Herencia, Carmen; Peralta, Alan; Almaden, Yolanda; Lopez, Ignacio; Aguilera-Tejero, Escolastico; Gundlach, Kristina; Büchel, Janine; Peter, Mirjam E.; Passlick-Deetjen, Jutta; Rodriguez, Mariano; Muñoz-Castañeda, Juan R.

2014-01-01

Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro

Ethanolic Extract of Traditional Chinese Medicine (TCM) Gamboge Inhibits Colon Cancer via the Wnt/Beta-Catenin Signaling Pathway in an Orthotopic Mouse Model.

Science.gov (United States)

Wang, Wei; Li, Youran; Chen, Yiqi; Chen, Hongjin; Zhu, Ping; Xu, Minmin; Wang, Hao; Wu, Minna; Yang, Zhijian; Hoffman, Robert M; Gu, Yunfei

2018-04-01

The aim of the present study was to investigate the efficacy of an ethanolic extract of gamboge (EEG), a traditional Chinese medicine (TCM), both in vitro on colon cancer cells and in vivo in an orthotopic mouse model of human colon cancer. The in vitro cytotoxicity of EEG on colon cancer cells was determined with the CCK8 proliferation assay and the Annexin V-PE/7-AAD apoptosis assay. Efficacy of EEG in vivo was evaluated in an orthotopic mouse model of human colon cancer implated with the green fluorescent protein-expressing human colon cancer cell line SW480-GFP. The tumor-bearing mice were treated with vehicle (0.2 ml/dose normal saline, po, daily), irinotecan (50 mg/kg/dose, ip, twice a week), 5-FU (15 mg/kg/dose, ip, every other day) as positive controls or EEG at doses of 12.5, 25 and 50 mg/kg/dose, po, daily. Real-time fluorescence imaging was performed to determine tumor inhibition in each treated group compared to the untreated controls. The protein expression of β-catenin, MMP-7, cyclin D1 and E-cadherin in the tumors was analyzed by immunohistochemistry. EEG significantly induced proliferation inhibition and apoptosis of SW480 colon cancer cells in vitro in a dose-dependent manner. Tumor growth in the colon-cancer orthotopic model was significantly inhibited by irinotecan, 5-FU and all three doses of EEG. The efficacy of EEG was comparable to irinotecan and 5-FU. Irinotecan, 5-FU and 50 mg/kg EEG significantly decreased the protein expression of β-catenin and MMP-7. Cyclin D1 expression was decreased and E-cadherin expression was increased by irinotecan, 5-FU and all three doses of EEG. The present study demonstrates anti-tumor efficacy of EEG on colon cancer both in vitro and in vivo through inducing proliferation inhibition and apoptosis of SW480 colon cancer cells and inhibiting tumor growth, respectively. EEG exerts anti-tumor activity at least partly via down-regulation of the Wnt/β-catenin signaling pathway. Copyright© 2018, International

Mitogen-Activated Protein Kinases Promote WNT/beta-Catenin Signaling via Phosphorylation of LRP6

Czech Academy of Sciences Publication Activity Database

Červenka, I.; Wolf, J.; Mašek, J.; Krejčí, Pavel; Wilcox, W. R.; Kozubík, Alois; Schulte, G.; Gutkind, J.S.; Bryja, Vítězslav

2011-01-01

Roč. 31, č. 1 (2011), s. 179-189 ISSN 0270-7306 R&D Projects: GA ČR(CZ) GC204/09/J030 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : WNT RECEPTOR ACTIVATION * BETA-CATENIN * CORECEPTOR LRP6 Subject RIV: BO - Biophysics Impact factor: 5.527, year: 2011

Inhibition of disheveled-2 resensitizes cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling.

Science.gov (United States)

Luo, Ke; Gu, Xiuhui; Liu, Jing; Zeng, Guodan; Peng, Liaotian; Huang, Houyi; Jiang, Mengju; Yang, Ping; Li, Minhui; Yang, Yuhan; Wang, Yuanyuan; Peng, Quekun; Zhu, Li; Zhang, Kun

2016-09-10

Cisplatin (CDDP) is currently recommended as the front-line chemotherapeutic agent for lung cancer. However, the resistance to cisplatin is widespread in patients with advanced lung cancer, and the molecular mechanism of such resistance remains incompletely understood. Disheveled (DVL), a key mediator of Wnt/β-catenin, has been linked to cancer progression, while the role of DVL in cancer drug resistance is not clear. Here, we found that DVL2 was over-expressed in cisplatin-resistant human lung cancer cells A549/CDDP compared to the parental A549 cells. Inhibition of DVL2 by its inhibitor (3289-8625) or shDVL2 resensitized A549/CDDP cells to cisplatin. In addition, over-expression of DVL2 in A549 cells increased the protein levels of BCRP, MRP4, and Survivin, which are known to be associated with chemoresistance, while inhibition of DVL2 in A549/CDDP cells decreased these protein levels, and reduced the accumulation and nuclear translocation of β-catenin. In addition, shβ-catenin abolished the DVL2-induced the expression of BCRP, MRP4, and Survivin. Furthermore, our data showed that GSK3β/β-catenin signals were aberrantly activated by DVL2, and inactivation of GSK3β reversed the shDVL2-induced down-regulation of β-catenin. Taken together, these results suggested that inhibition of DVL2 can sensitize cisplatin-resistant lung cancer cells through down-regulating Wnt/β-catenin signaling and inhibiting BCRP, MRP4, and Survivin expression. It promises a new strategy to chemosensitize cisplatin-induced cytotoxicity in lung cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of β-catenin

International Nuclear Information System (INIS)

Cho, Il-Rae; Koh, Sang Seok; Malilas, Waraporn; Srisuttee, Ratakorn; Moon, Jeong; Choi, Young-Whan; Horio, Yoshiyuki; Oh, Sangtaek; Chung, Young-Hwa

2012-01-01

Highlights: ► SIRT1 inhibits protein levels of β-catenin and its transcriptional activity. ► Nuclear localization of SIRT1 is not required for the decrease of β-catenin expression. ► SIRT1-mediated degradation of β-catenin is not required for GSK-3β and Siah-1 but for proteosome. ► SIRT1 activation inhibits proliferation of pancreatic cancer cells expressing PAUF. -- Abstract: Because we found in a recent study that pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, induces a rapid proliferation of pancreatic cells by up-regulation of β-catenin, we postulated that β-catenin might be a target molecule for pancreatic cancer treatment. We thus speculated whether SIRT1, known to target β-catenin in a colon cancer model, suppresses β-catenin in those pancreatic cancer cells that express PAUF (Panc-PAUF). We further evaluated whether such suppression would lead to inhibition of the proliferation of these cells. The ectopic expression of either SIRT1 or resveratrol (an activator of SIRT1) suppressed levels of β-catenin protein and its transcriptional activity in Panc-PAUF cells. Conversely, suppression of SIRT1 expression by siRNA enhanced β-catenin expression and transcriptional activity. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for reduction of β-catenin. Treatment with MG132, a proteasomal inhibitor, restored β-catenin protein levels, suggesting that SIRT1-mediated degradation of β-catenin requires proteasomal activity. It was reported that inhibition of GSK-3β or Siah-1 stabilizes β-catenin in colon cancer cells, but suppression of GSK-3β or Siah-1 using siRNA in the presence of resveratrol instead diminished β-catenin protein levels in Panc-PAUF cells. This suggests that GSK-3β and Siah-1 are not involved in SIRT1-mediated degradation of β-catenin in the cells. Finally, activation of SIRT1 inhibited the proliferation of Panc-PAUF cells by down-regulation of cyclin-D1, a target

Attenuated Response to Methamphetamine Sensitization and Deficits in Motor Learning and Memory after Selective Deletion of [beta]-Catenin in Dopamine Neurons

Science.gov (United States)

Diaz-Ruiz, Oscar; Zhang, YaJun; Shan, Lufei; Malik, Nasir; Hoffman, Alexander F.; Ladenheim, Bruce; Cadet, Jean Lud; Lupica, Carl R.; Tagliaferro, Adriana; Brusco, Alicia; Backman, Cristina M.

2012-01-01

In the present study, we analyzed mice with a targeted deletion of [beta]-catenin in DA neurons (DA-[beta]cat KO mice) to address the functional significance of this molecule in the shaping of synaptic responses associated with motor learning and following exposure to drugs of abuse. Relative to controls, DA-[beta]cat KO mice showed significant…

Effect of Huayu Tongluo Herbs on Reduction of Proteinuria via Inhibition of Wnt/β-Catenin Signaling Pathway in Diabetic Rats

Directory of Open Access Journals (Sweden)

Lu Bai

2017-01-01

Full Text Available The study investigated the expression of Wnt/β-catenin pathway in diabetic rats and the intervention effect of Huayu Tongluo herbs (HTH. Ten rats were randomly selected as control group and the remaining rats were established as diabetic models. The diabetic rats were randomly divided into model group and HTH treatment group. The intervention was intragastric administration in all rats for 20 weeks. At the end of every 4 weeks, fasting blood glucose and 24 h urinary total protein quantitatively were measured. At the end of the 20th week, biochemical parameters and body weight were tested. The kidney tissues were observed under light microscope and transmission electron microscopy. We examined Wnt/beta-catenin signaling pathway key proteins and renal interstitial fibrosis related molecular markers expression. The results showed that HTH could reduce urinary protein excretion and relieve renal pathological damage. Wnt4, p-GSK3β (S9, and β-catenin expression were decreased in the signaling pathway, but GSK3β level was not changed by HTH in diabetic rats. Furthermore, the expressions of TGF-β1 and ILK were decreased, but the level of E-cadherin was increased in diabetic rats after treatment with HTH. This study demonstrated that HTH could inhibit the high expression of Wnt/β-catenin pathway in kidney of diabetic rats. The effect might be one of the main ways to reduce urinary protein excretion.

RNA helicase DDX3 is a regulatory subunit of casein kinase 1 in Wnt-beta-catenin signaling

NARCIS (Netherlands)

Cruciat, C.M.; Dolde, C.; de Groot, R.E.; Ohkawara, B.; Reinhard, C.; Korswagen, H.C.; Niehrs, C.

2013-01-01

Casein kinase 1 (CK1) members play key roles in numerous biological processes. They are considered "rogue" kinases, because their enzymatic activity appears unregulated. Contrary to this notion, we have identified the DEAD-box RNA helicase DDX3 as a regulator of the Wnt-beta-catenin network, where

Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung-Mi [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of); Yun, Ji Ho [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Lee, Dong Hwa [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Park, Young Gyun [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Son, Kun Ho [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Kim, Yeong Shik, E-mail: kims@snu.ac.kr [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of)

2015-04-17

We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus.

Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

International Nuclear Information System (INIS)

Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

2015-01-01

We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus

Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes

Energy Technology Data Exchange (ETDEWEB)

Kim, Mi-Bo [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Song, Youngwoo; Kim, Changhee [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

2014-03-07

Highlights: • Kirenol inhibits the adipogenic transcription factors and lipogenic enzymes. • Kirenol stimulates the Wnt/β-catenin signaling pathway components. • Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway. - Abstract: Kirenol, a natural diterpenoid compound, has been reported to possess anti-oxidant, anti-inflammatory, anti-allergic, and anti-arthritic activities; however, its anti-adipogenic effect remains to be studied. The present study evaluated the effect of kirenol on anti-adipogenesis through the activation of the Wnt/β-catenin signaling pathway. Kirenol prevented intracellular lipid accumulation by down-regulating key adipogenesis transcription factors [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and sterol regulatory element binding protein-1c (SREBP-1c)] and lipid biosynthesis-related enzymes [fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC)], as well as adipocytokines (adiponectin and leptin). Kirenol effectively activated the Wnt/β-catenin signaling pathway, in which kirenol up-regulated the expression of low density lipoprotein receptor related protein 6 (LRP6), disheveled 2 (DVL2), β-catenin, and cyclin D1 (CCND1), while it inactivated glycogen synthase kinase 3β (GSK3β) by increasing its phosphorylation. Kirenol down-regulated the expression levels of PPARγ and C/EBPα, which were up-regulated by siRNA knockdown of β-catenin. Overall, kirenol is capable of inhibiting the differentiation and lipogenesis of 3T3-L1 adipocytes through the activation of the Wnt/β-catenin signaling pathway, suggesting its potential as natural anti-obesity agent.

Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/β-catenin pathway

International Nuclear Information System (INIS)

Patel, Rachana; Ingle, Arvind; Maru, Girish B.

2008-01-01

Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/β-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating β-catenin by maintaining expression of APC and decreasing inactivation of GSK3β. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through β-catenin regulation

Functions of Beta- and Gamma-Catenins in Prostate Cancer

National Research Council Canada - National Science Library

Reed, John

1999-01-01

.... We recently discovered that the protein Siah-1 interacts with the APC/catenin complex, and regulates the ubiquitin-dependent turnover of gamma-catenin through a novel previously unidentified mechanism...

Wnt/β-catenin signaling promotes self-renewal and inhibits the primed state transition in naïve human embryonic stem cells.

Science.gov (United States)

Xu, Zhuojin; Robitaille, Aaron M; Berndt, Jason D; Davidson, Kathryn C; Fischer, Karin A; Mathieu, Julie; Potter, Jennifer C; Ruohola-Baker, Hannele; Moon, Randall T

2016-10-18

In both mice and humans, pluripotent stem cells (PSCs) exist in at least two distinct states of pluripotency, known as the naïve and primed states. Our understanding of the intrinsic and extrinsic factors that enable PSCs to self-renew and to transition between different pluripotent states is important for understanding early development. In mouse embryonic stem cells (mESCs), Wnt proteins stimulate mESC self-renewal and support the naïve state. In human embryonic stem cells (hESCs), Wnt/β-catenin signaling is active in naïve-state hESCs and is reduced or absent in primed-state hESCs. However, the role of Wnt/β-catenin signaling in naïve hESCs remains largely unknown. Here, we demonstrate that inhibition of the secretion of Wnts or inhibition of the stabilization of β-catenin in naïve hESCs reduces cell proliferation and colony formation. Moreover, we show that addition of recombinant Wnt3a partially rescues cell proliferation in naïve hESCs caused by inhibition of Wnt secretion. Notably, inhibition of Wnt/β-catenin signaling in naïve hESCs did not cause differentiation. Instead, it induced primed hESC-like proteomic and metabolic profiles. Thus, our results suggest that naïve hESCs secrete Wnts that activate autocrine or paracrine Wnt/β-catenin signaling to promote efficient self-renewal and inhibit the transition to the primed state.

DAX-1 Inhibits Hepatocellular Carcinoma Proliferation by Inhibiting β-Catenin Transcriptional Activity

Directory of Open Access Journals (Sweden)

Hong-Lei Jiang

2014-08-01

Full Text Available Background/Aims: Hepatocellular carcinoma (HCC represents the most common type of liver cancer. DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1, an atypical member of the nuclear receptor family due to lack of classical DNA-binding domains, has been known for its fundamental roles in the development, especially in the sex determination and steroidogenesis. Previous studies also showed that DAX-1 played a critical role in endocrine and sex steroid-dependent neoplasms such as adrenocortical, pituitary, endometrial, and ovarian tumors. However, its biological roles in the development of HCC remain largely unexplored. Methods: Real-time PCR and Western blot were used to detect the expression of DAX-1 in HCC tissues and cell lines. Immunoprecipitation (IP assay was used to show the interaction between DAX-1 and β-Catenin. Small interfering RNA (siRNA was used to silence the expression of DAX-1. BrdU incorporation and Cell-cycle assays were used to detect the role of DAX-1 in HCC cells proliferation. Migration and invasion assays were carried out to test the metastasis ability of DAX-1 in HCC cells. Results: In the present study, we found that mRNA and protein levels of DAX-1 were down-regulated in HCC tissues and cell lines. Furthermore, overexpression of DAX-1 could inhibit while its knockdown using small interfering RNA promoted cell proliferation in several HCC cell lines. At the molecular level, we demonstrated that DAX-1 could interact with β-Catenin and attenuate its transcriptional activity. Conclusion: Therefore, our results suggest a previously unknown DAX-1/β-Catenin molecular network controlling HCC development.

Mouse Tcf3 represses canonical Wnt signaling by either competing for beta-catenin binding or through occupation of DNA-binding sites

Czech Academy of Sciences Publication Activity Database

Solberg, N.; Machoň, Ondřej; Machoňová, Olga; Krauss, S.

2012-01-01

Roč. 365, 1-2 (2012), s. 53-63 ISSN 0300-8177 Institutional support: RVO:68378050 Keywords : Tcf3 * repressor * interaction * beta-catenin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.329, year: 2012

Analysis of beta-catenin, Ki-ras, and microsatellite stability in azoxymethane-induced colon tumors of BDIX/Orl Ico rats

DEFF Research Database (Denmark)

Sørensen, Nanna Møller; Kobaek-Larsen, Morten; Bonne, Anita

2003-01-01

The aim of the study reported here was to investigate whether the azoxymethane (AOM)-induced colon cancer rat model mimics the human situation with regard to microsatellite stability, changes in expression of beta-catenin, and/or changes in the sequence of the proto-oncogene Ki-ras. Colon cancer ...

miR-449 overexpression inhibits papillary thyroid carcinoma cell growth by targeting RET kinase-β-catenin signaling pathway.

Science.gov (United States)

Li, Zongyu; Huang, Xin; Xu, Jinkai; Su, Qinghua; Zhao, Jun; Ma, Jiancang

2016-10-01

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and represent approximately 80% of all thyroid cancers. The present study is aimed to investigate the role of microRNA (miR)-449 in the progression of PTC. Our results revealed that miR-449 was underexpressed in the collected PTC specimens compared with non-cancerous PTC tissues. Overexpression of miR-449 induced a cell cycle arrest at G0/G1 phase and inhibited PTC cell growth in vitro. Further studies revealed that RET proto-oncogene (RET) is a novel miR-449 target, due to miR-449 bound directly to its 3'-untranslated region and miR-449 mimic reduced the protein expression of RET. Similar to the effects of miR-449 overexpression, RET downregulation inhibited cell growth, whereas RET overexpression reversed the inhibitive effect of miR-449 mimic. Furthermore, miR-449 overexpression inhibited the nuclear translocation of β-catenin and reduced the expression of several downstream genes, including c-Myc, cyclin D1, T cell-specific transcription factor (TCF) and lymphoid enhancer-binding factor 1 (LEF-1), and inactivated the β-catenin pathway in TPC-1 cells. Moreover, overexpression of β-catenin prevented miR-449-reduced cell cycle arrest and cell viability. In xenograft animal experiments, miR-449 overexpression effectively suppressed the tumor growth of PTC. Taken together, our research indicated that miR-449 functions as an anti-oncogene by targeting RET, and that miR-449 overexpression inhibited the growth of PTC by inactivating the β-catenin pathway. Thus, miR-449 may serve as a potential therapeutic strategy for the treatment of PTC.

The N-Terminal Part of the Dishevelled DEP Domain Is Required for Wnt/beta-Catenin Signaling in Mammalian Cells

Czech Academy of Sciences Publication Activity Database

Pacliková, P.; Bernatík, O.; Radaszkiewicz, T.W.; Bryja, Vítězslav

2017-01-01

Roč. 37, č. 18 (2017), č. článku e00145-17. ISSN 0270-7306 Institutional support: RVO:68081707 Keywords : beta-catenin * tumor-suppressor * planar polarity Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 4.398, year: 2016

Fluoxetine Regulates Neurogenesis In Vitro Through Modulation of GSK-3β/β-Catenin Signaling

Science.gov (United States)

Hui, Jiaojie; Zhang, Jianping; Kim, Hoon; Tong, Chang; Ying, Qilong; Li, Zaiwang; Mao, Xuqiang; Shi, Guofeng; Yan, Jie; Zhang, Zhijun

2015-01-01

Background: It is generally accepted that chronic treatment with antidepressants increases hippocampal neurogenesis, but the molecular mechanisms underlying their effects are unknown. Recently, glycogen synthase kinase-3 beta (GSK-3β)/β-catenin signaling was shown to be involved in the mechanism of how antidepressants might influence hippocampal neurogenesis. Methods: The aim of this study was to determine whether GSK-3β/β-catenin signaling is involved in the alteration of neurogenesis as a result of treatment with fluoxetine, a selective serotonin reuptake inhibitor. The mechanisms involved in fluoxetine’s regulation of GSK-3β/β-catenin signaling pathway were also examined. Results: Our results demonstrated that fluoxetine increased the proliferation of embryonic neural precursor cells (NPCs) by up-regulating the phosphorylation of Ser9 on GSK-3β and increasing the level of nuclear β-catenin. The overexpression of a stabilized β-catenin protein (ΔN89 β-catenin) significantly increased NPC proliferation, while inhibition of β-catenin expression in NPCs led to a significant decrease in the proliferation and reduced the proliferative effects induced by fluoxetine. The effects of fluoxetine-induced up-regulation of both phosphorylation of Ser9 on GSK-3β and nuclear β-catenin were significantly prevented by the 5-hydroxytryptamine-1A (5-HT1A) receptor antagonist WAY-100635. Conclusions: The results demonstrate that fluoxetine may increase neurogenesis via the GSK-3β/β-catenin signaling pathway that links postsynaptic 5-HT1A receptor activation. PMID:25522429

Inhibition of the WNT/β-catenin pathway by fine particulate matter in haze: Roles of metals and polycyclic aromatic hydrocarbons

Science.gov (United States)

Lee, Kang-Yun; Cao, Jun-Ji; Lee, Chii-Hong; Hsiao, Ta-Chih; Yeh, Chi-Tai; Huynh, Thanh-Tuan; Han, Yong-Ming; Li, Xiang-Dong; Chuang, Kai-Jen; Tian, Linwei; Ho, Kin-Fai; Chuang, Hsiao-Chi

2015-05-01

Air pollution might have a great impact on pulmonary health, but biological evidence in response to particulate matter less than 2.5 μm in size (PM2.5) has been lacking. Physicochemical characterization of haze PM2.5 collected from Beijing, Xian and Hong Kong was performed. Biological pathways were identified by proteomic profiling in mouse lungs, suggesting that WNT/β-catenin is important in the response to haze PM2.5. Suppression of β-catenin levels, activation of caspase-3 and alveolar destruction, as well as IL-6, TNF-α and IFN-γ production, were observed in the lungs. The inhibition of β-catenin, TCF4 and cyclin D1 was observed in vitro in response to haze PM2.5. The inhibition of WNT/β-catenin signaling, apoptosis-related results (caspase-3 and alveolar destruction), and inflammation, particularly including caspase-3 and alveolar destruction, were more highly associated with polycyclic aromatic hydrocarbons in haze PM2.5. In conclusion, decreased WNT/β-catenin expression modulated by haze PM2.5 could be involved in alveolar destruction and inflammation during haze episodes.

The destruction complex of beta-catenin in colorectal carcinoma and colonic adenoma.

Science.gov (United States)

Bourroul, Guilherme Muniz; Fragoso, Hélio José; Gomes, José Walter Feitosa; Bourroul, Vivian Sati Oba; Oshima, Celina Tizuko Fujiyama; Gomes, Thiago Simão; Saba, Gabriela Tognini; Palma, Rogério Tadeu; Waisberg, Jaques

2016-01-01

To evaluate the destruction complex of beta-catenin by the expression of the proteins beta-catetenin, adenomatous polyposis coli, GSK3β, axin and ubiquitin in colorectal carcinoma and colonic adenoma. Tissue samples from 64 patients with colorectal carcinoma and 53 patients with colonic adenoma were analyzed. Tissue microarray blocks and slides were prepared and subjected to immunohistochemistry with polyclonal antibodies in carcinoma, adjacent non-neoplastic mucosa, and adenoma tissues. The immunoreactivity was evaluated by the percentage of positive stained cells and by the intensity assessed through of the stained grade of proteins in the cytoplasm and nucleus of cells. In the statistical analysis, the Spearman correlation coefficient, Student's t, χ2, Mann-Whitney, and McNemar tests, and univariate logistic regression analysis were used. In colorectal carcinoma, the expressions of beta-catenin and adenomatous polyposis coli proteins were significantly higher than in colonic adenomas (pcitoplasma e no núcleo das células. Na análise estatística, foram utilizados o coeficiente de correlação de Spearman, os testes t de Student, χ2, Mann-Whitney e de McNemar, e a análise de regressão logística univariada. No carcinoma colorretal, as expressões da betacatenina e da adenomatous polyposis coli foram significativamente maiores do que em adenomas do colo (p<0,001 e p<0,0001, respectivamente). A imunorreatividade das proteínas GSK3β, axina 1 e ubiquitina foi significativamente maior (p=0,03, p=0,039 e p=0,03, respectivamente) no carcinoma colorretal do que no adenoma e na mucosa não neoplásica adjacente. A coloração imuno-histoquímica dessas proteínas não apresentou diferenças significantes em relação às características clinicopatológicas do câncer colorretal e do adenoma. Em adenomas, as menores expressões de betacatenina, axina 1 e GSK3β indicaram que o complexo de destruição da betacatenina estava conservado, enquanto que, no carcinoma

TIPE2 Inhibits the Expression of Asthma-Related Inflammatory Factors in Hyperstretched Bronchial Epithelial Cells Through the Wnt/β-Catenin Pathway.

Science.gov (United States)

Sun, Xinrong; Chen, Lu; Yan, Wen

2017-06-01

Childhood asthma, an airway inflammatory disease, is a serious threat to the child's quality of life. Recently, TIPE2 expression was reported to be decreased in children with asthma. Therefore, additional studies focusing on TIPE2 might provide an approach for treating childhood asthma. In this study, we found that TIPE2 was poorly expressed in hyperstretched human bronchial epithelial cells (BEAS-2B). TIPE2 overexpression also significantly suppressed the stretch-induced secretion of asthma-related inflammatory factors (TNF-α, TSLP, MMP-9, and VEGF). In contrast, TIPE2 inhibition significantly promoted the secretion of TNF-α, TSLP, MMP-9, and VEGF. Furthermore, overexpression of TIPE2 remarkably inhibited the activation of Wnt/β-catenin in hyperstretched BEAS-2B cells, while siTIPE2 activated Wnt/β-catenin in hyperstretched BEAS-2B cells. Further analysis showed that the Wnt/β-catenin signal inhibitor Dkk-1 could further enhance the TIPE2-induced suppression of Wnt/β-catenin signaling, which also suppressed the siTIPE2-induced secretion of TNF-α, TSLP, MMP-9, and VEGF in hyperstretched BEAS-2B cells. Dkk-1 reversed the effects of siRNA-TIPE2 on Wnt/β-catenin signaling and inflammatory cytokines. In summary, we have exhibited that TIPE2 inhibited the expression of asthma-related inflammatory factors in hyperstretched BEAS-2B cells by suppressing the Wnt/β-catenin signaling pathway. TIPE2 may be involved in airway inflammation during asthma attack, and it may be used as a potential therapeutic target for bronchial epithelial inflammation in childhood asthma.

Hydrocephalus caused by conditional ablation of the Pten or beta-catenin gene

Directory of Open Access Journals (Sweden)

Ohtoshi Akihira

2008-10-01

Full Text Available Abstract To investigate the roles of Pten and β-Catenin in the midbrain, either the Pten gene or the β-catenin gene was conditionally ablated, using Dmbx1 (diencephalon/mesencephalon-expressed brain homeobox gene 1-Cre mice. Homozygous disruption of the Pten or β-catenin gene in Dmbx1-expressing cells caused severe hydrocephalus and mortality during the postnatal period. Conditional deletion of Pten resulted in enlargement of midbrain structures. β-catenin conditional mutant mice showed malformation of the superior and inferior colliculi and stenosis of the midbrain aqueduct. These results demonstrate that both Pten and β-Catenin are essential for proper midbrain development, and provide the direct evidence that mutations of both Pten and β-catenin lead to hydrocephalus.

Targeted inhibition of disheveled PDZ domain via NSC668036 depresses fibrotic process

Energy Technology Data Exchange (ETDEWEB)

Wang, Cong, E-mail: wangcongweihai@126.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Dai, Jinghong, E-mail: daijinghongnew@163.com [Department of Respiratory Medicine, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University (China); Sun, Zhaorui, E-mail: lanseyunduan@163.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Department of Emergency, Jinling Hospital, Medical School, Nanjing University, Nanjing, Jiangsu 210093 (China); Shi, Chaowen, E-mail: willscw@live.cn [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Cao, Honghui, E-mail: caohonghui92@gmail.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); and others

2015-02-01

In this study, we determined the effects of transforming growth factor-beta (TGF-β) and Wnt/β-catenin signaling on myofibroblast differentiation of NIH/3T3 fibroblasts in vitro and evaluated the therapeutic efficacy of NSC668036 in bleomycin-induced pulmonary fibrosis murine model. In vitro study, NSC668036, a small organic inhibitor of the PDZ domain in Dvl, suppressed β-catenin-driven gene transcription and abolished TGF-β1-induced migration, expression of collagen I and α-smooth muscle actin (α-SMA) in fibroblasts. In vivo study, we found that NSC668036 significantly suppressed accumulation of collagen I, α-SMA, and TGF-β1 but increased the expression of CK19, Occludin and E-cadherin that can inhibit pulmonary fibrogenesis. Because fibrotic lung exhibit aberrant activation of Wnt/β-catenin signaling, these data collectively suggest that inhibition of Wnt/β-catenin signaling at the Dvl level may be an effective approach to the treatment of fibrotic lung diseases. - Highlights: • NSC668036 inhibited the proliferation and migration of NIH/3T3 fibroblasts. • NSC668036 suppressed the Wnt/β-catenin signaling pathway. • TGF-β-induced stimulation of profibrotic responses were inhibited by NSC668036. • NSC668036 can inhibit the development of bleomycin-induced pulmonary fibrosis.

Interactions between β-catenin and the HSlo potassium channel regulates HSlo surface expression.

Directory of Open Access Journals (Sweden)

Shumin Bian

Full Text Available The large conductance calcium-activated potassium channel alpha-subunit (Slo is widely distributed throughout the body and plays an important role in a number of diseases. Prior work has shown that Slo, through its S10 region, interacts with β-catenin, a key component of the cytoskeleton framework and the Wnt signaling pathway. However, the physiological significance of this interaction was not clear.Using a combination of proteomic and cell biology tools we show the existence of additional multiple binding sites in Slo, and explore in detail β-catenin interactions with the S10 region. We demonstrate that deletion of this region reduces Slo surface expression in HEK cells, which indicates that interaction with beta-catenin is important for Slo surface expression. This is confirmed by reduced expression of Slo in HEK cells and chicken (Gallus gallus domesticus leghorn white hair cells treated with siRNA to β-catenin. HSlo reciprocally co-immunoprecipitates with β-catenin, indicating a stable binding between these two proteins, with the S10 deletion mutant having reduced binding with β-catenin. We also observed that mutations of the two putative GSK phosphorylation sites within the S10 region affect both the surface expression of Slo and the channel's voltage and calcium sensitivities. Interestingly, expression of exogenous Slo in HEK cells inhibits β-catenin-dependent canonical Wnt signaling.These studies identify for the first time a central role for β-catenin in mediating Slo surface expression. Additionally we show that Slo overexpression can lead to downregulation of Wnt signaling.

Attenuation of the beta-catenin/TCF4 complex in colorectal cancer cells induces several growth-suppressive microRNAs that target cancer promoting genes

DEFF Research Database (Denmark)

Schepeler, Troels; Holm, Anja; Halvey, P

2012-01-01

Aberrant activation of the Wnt signaling pathway is causally involved in the formation of most colorectal cancers (CRCs). Although detailed knowledge exists regarding Wnt-regulated protein-coding genes, much less is known about the possible involvement of non-coding RNAs. Here we used TaqMan Array......RNAs are upregulated as a consequence of forced attenuation of Wnt signaling in CRC cells, and some of these miRNAs inhibit cell growth with concomitant suppression of several growth-stimulatory cancer-related genes....... MicroRNA Cards, capable of detecting 664 unique human microRNAs (miRNAs), to describe changes of the miRNA transcriptome following disruption of beta-catenin/TCF4 activity in DLD1 CRC cells. Most miRNAs appeared to respond independent of host gene regulation and proximal TCF4 chromatin occupancy...

A high-fat diet generates alterations in nuclear receptor expression: prevention by vitamin A and links with cyclooxygenase-2 and beta-catenin.

Science.gov (United States)

Delage, Barbara; Bairras, Céline; Buaud, Benjamin; Pallet, Véronique; Cassand, Pierrette

2005-10-10

Epidemiologic studies suggest that intake of high energy from fat, inducing overweight, increases the risk of cancer development and promotes colon carcinogenesis. It is therefore important to understand which parameters are affected early on by a high-fat diet in order to devise and improve protective nutritional strategies. We investigated the effect of high energy/fat intake on colon mucosa of male Wistar rats induced by a single 1,2-dimethylhydrazine (DMH) injection. Aberrant crypt foci (ACF) were numbered and modifications in cyclooxygenase-2 (COX-2) and beta-catenin levels assessed. Peroxisome proliferator- and retinoic acid-activated receptors (PPAR and RAR, RXR) are key transcription factors regulating gene expression in response to nutrient-activated signals. A short-term study was designed to evaluate whether alterations in mRNA expression of nuclear receptors can be detected at the beginning of the weight gain phase induced by an appetizing hyperlipidic diet (HLD). HLD consumption induced early downregulation of PPARgamma (-33.1%) and RARbeta (-53.1%) mRNA expression concomitant with an increase in levels of COX-2 (+45.5%) and beta-catenin (+84.56%) and in the number of ACF (191.56 +/- 88.60 vs. 21.14 +/- 11.64, p nuclear receptors. Moreover, the use HLD rich in retinyl esters or supplemented with all-trans retinoic acid led to a reduction in the number of ACF. Vitamin A also prevented HLD-induced alterations and the increase in levels of COX-2 and beta-catenin. The present observations show a protective role for vitamin A against disturbances associated with HLD exposure in induced colon carcinogenesis.

The Regulation of the Angiogenic Factor FGF Binding Protein (FGF-BP) by the APC/Beta-Catenin Signaling Pathway in the Progression of Breast Cancer

National Research Council Canada - National Science Library

Stylianou, Dora

2004-01-01

...) to study the expression of FGF-BP in mammary tumorigenesis progression of the APC/+ mouse and 2) to determine the mechanism of regulation of FGF-BP b the APC/beta-catenin signaling pathway in breast cancer...

The Regulation of the Angiogenic Factor FGF Binding Protein (FGF-BP) by the APC/Beta-Catenin Signaling Pathway in the Progression of Breast Cancer

National Research Council Canada - National Science Library

Stylianou, Dora

2003-01-01

...) to study the expression of FGF-BP in mammary tumorigenesis% progression of the APC/+ mouse and 2) to determine the mechanism of regulation of FGF-BP by the APC/beta- catenin signaling pathway in breast cancer...

Expressão de galectina-3 e beta-catenina em lesões pré-malignas e carcinomatosas de língua de camundongos Galectin-3 and beta-catenin expression in premalignant and carcinomatous lesions in tongue of mice

Directory of Open Access Journals (Sweden)

Juliana Moreira de Almeida Sant'ana

2011-02-01

Full Text Available INTRODUÇÃO: A galectina-3 (GAL3 apresenta importantes papéis na biologia tumoral e recentemente foi mostrada a sua participação na via de sinalização Wnt, translocando a beta-catenina para o núcleo. Expressão alterada de GAL3 e beta-catenina tem sido descrita em cânceres, mas não há estudos avaliando a expressão de ambas em displasias e carcinomas desenvolvidos em modelos de carcinogênese de língua. OBJETIVOS: Estudar a expressão de GAL3 e beta-catenina em lesões displásicas e carcinomas induzidos experimentalmente em língua de camundongos. MATERIAL E MÉTODOS: Vinte camundongos C57BL/6 machos foram desafiados com 4NQO na água de beber por 16 semanas e sacrificados na semana 16 e 32. Após o sacrifício, as línguas foram removidas, processadas, coradas por hematoxilina e eosina (HE para detecção de displasias e carcinomas. Ensaio imuno-histoquímico foi realizado para determinar o índice de positividade para GAL3 e beta-catenina nessas lesões, bem como uma correlação entre elas em carcinomas. RESULTADOS: O número de camundongos afetados por carcinoma aumentou entre as semanas 16 e 32 (22,2% vs. 88,9% e o de displasia diminuiu (66,7% vs. 11,1%. Um aumento de células positivas para beta-catenina não membranosa e GAL3 citoplasmática foi observado nas displasias e nos carcinomas, mas essa diferença não foi estatisticamente significativa. No entanto, um aumento estatisticamente significativo de GAL3 nuclear foi observado na evolução de displasia para carcinoma (p = 0,04. Nenhuma correlação foi encontrada entre beta-catenina e GAL3. CONCLUSÃO: Tanto nas displasias quanto nos carcinomas a via de sinalização Wnt está ativa, e o aumento de GAL3 nuclear nos carcinomas sugere um papel na transformação maligna do epitélio lingual.INTRODUCTION: Galectin-3 plays pivotal role in tumor biology and its participation in Wnt signaling pathway translocating beta-catenin into the nucleus has been recently demonstrated

Neural induction in Xenopus: requirement for ectodermal and endomesodermal signals via Chordin, Noggin, beta-Catenin, and Cerberus.

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Hiroki Kuroda

2004-05-01

Full Text Available The origin of the signals that induce the differentiation of the central nervous system (CNS is a long-standing question in vertebrate embryology. Here we show that Xenopus neural induction starts earlier than previously thought, at the blastula stage, and requires the combined activity of two distinct signaling centers. One is the well-known Nieuwkoop center, located in dorsal-vegetal cells, which expresses Nodal-related endomesodermal inducers. The other is a blastula Chordin- and Noggin-expressing (BCNE center located in dorsal animal cells that contains both prospective neuroectoderm and Spemann organizer precursor cells. Both centers are downstream of the early beta-Catenin signal. Molecular analyses demonstrated that the BCNE center was distinct from the Nieuwkoop center, and that the Nieuwkoop center expressed the secreted protein Cerberus (Cer. We found that explanted blastula dorsal animal cap cells that have not yet contacted a mesodermal substratum can, when cultured in saline solution, express definitive neural markers and differentiate histologically into CNS tissue. Transplantation experiments showed that the BCNE region was required for brain formation, even though it lacked CNS-inducing activity when transplanted ventrally. Cell-lineage studies demonstrated that BCNE cells give rise to a large part of the brain and retina and, in more posterior regions of the embryo, to floor plate and notochord. Loss-of-function experiments with antisense morpholino oligos (MO showed that the CNS that forms in mesoderm-less Xenopus embryos (generated by injection with Cerberus-Short [CerS] mRNA required Chordin (Chd, Noggin (Nog, and their upstream regulator beta-Catenin. When mesoderm involution was prevented in dorsal marginal-zone explants, the anterior neural tissue formed in ectoderm was derived from BCNE cells and had a complete requirement for Chd. By injecting Chd morpholino oligos (Chd-MO into prospective neuroectoderm and Cerberus

γ-Catenin at Adherens Junctions: Mechanism and Biologic Implications in Hepatocellular Cancer after β-Catenin Knockdown

Directory of Open Access Journals (Sweden)

Emily Diane Wickline

2013-04-01

Full Text Available β-Catenin is important in liver homeostasis as a part of Wnt signaling and adherens junctions (AJs, while its aberrant activation is observed in hepatocellular carcinoma (HCC. We have reported hepatocyte-specific β-catenin knockout (KO mice to lack adhesive defects as γ-catenin compensated at AJ. Because γ-catenin is a desmosomal protein, we asked if its increase in KO might deregulate desmosomes. No changes in desmosomal proteins or ultrastructure other than increased plakophilin-3 were observed. To further elucidate the role and regulation of γ-catenin, we contemplate an in vitro model and show γ-catenin increase in HCC cells upon β-catenin knockdown (KD. Here, γ-catenin is unable to rescue β-catenin/T cell factor (TCF reporter activity; however, it sufficiently compensates at AJs as assessed by scratch wound assay, centrifugal assay for cell adhesion (CAFCA, and hanging drop assays. γ-Catenin increase is observed only after β-catenin protein decrease and not after blockade of its transactivation. γ-Catenin increase is associated with enhanced serine/threonine phosphorylation and abrogated by protein kinase A (PKA inhibition. In fact, several PKA-binding sites were detected in γ-catenin by in silico analysis. Intriguingly γ-catenin KD led to increased β-catenin levels and transactivation. Thus, γ-catenin compensates for β-catenin loss at AJ without affecting desmosomes but is unable to fulfill functions in Wnt signaling. γ-Catenin stabilization after β-catenin loss is brought about by PKA. Catenin-sensing mechanism may depend on absolute β-catenin levels and not its activity. Anti-β-catenin therapies for HCC affecting total β-catenin may target aberrant Wnt signaling without negatively impacting intercellular adhesion, provided mechanisms leading to γ-catenin stabilization are spared.

Effect of oxygen on cardiac differentiation in mouse iPS cells: role of hypoxia inducible factor-1 and Wnt/beta-catenin signaling.

Directory of Open Access Journals (Sweden)

Tanya L Medley

Full Text Available BACKGROUND: Disturbances in oxygen levels have been found to impair cardiac organogenesis. It is known that stem cells and differentiating cells may respond variably to hypoxic conditions, whereby hypoxia may enhance stem cell pluripotency, while differentiation of multiple cell types can be restricted or enhanced under hypoxia. Here we examined whether HIF-1alpha modulated Wnt signaling affected differentiation of iPS cells into beating cardiomyocytes. OBJECTIVE: We investigated whether transient and sustained hypoxia affects differentiation of cardiomyocytes derived from murine induced pluripotent stem (iPS cells, assessed the involvement of HIF-1alpha (hypoxia-inducible factor-1alpha and the canonical Wnt pathway in this process. METHODS: Embryoid bodies (EBs derived from iPS cells were differentiated into cardiomyocytes and were exposed either to 24 h normoxia or transient hypoxia followed by a further 13 days of normoxic culture. RESULTS: At 14 days of differentiation, 59 ± 2% of normoxic EBs were beating, whilst transient hypoxia abolished beating at 14 days and EBs appeared immature. Hypoxia induced a significant increase in Brachyury and islet-1 mRNA expression, together with reduced troponin C expression. Collectively, these data suggest that transient and sustained hypoxia inhibits maturation of differentiating cardiomyocytes. Compared to normoxia, hypoxia increased HIF-1alpha, Wnt target and ligand genes in EBs, as well as accumulation of HIF-1alpha and beta-catenin in nuclear protein extracts, suggesting involvement of the Wnt/beta-catenin pathway. CONCLUSION: Hypoxia impairs cardiomyocyte differentiation and activates Wnt signaling in undifferentiated iPS cells. Taken together the study suggests that oxygenation levels play a critical role in cardiomyocyte differentiation and suggest that hypoxia may play a role in early cardiogenesis.

Mechanical unloading reduces microtubule actin crosslinking factor 1 expression to inhibit β-catenin signaling and osteoblast proliferation.

Science.gov (United States)

Yin, Chong; Zhang, Yan; Hu, Lifang; Tian, Ye; Chen, Zhihao; Li, Dijie; Zhao, Fan; Su, Peihong; Ma, Xiaoli; Zhang, Ge; Miao, Zhiping; Wang, Liping; Qian, Airong; Xian, Cory J

2018-07-01

Mechanical unloading was considered a major threat to bone homeostasis, and has been shown to decrease osteoblast proliferation although the underlying mechanism is unclear. Microtubule actin crosslinking factor 1 (MACF1) is a cytoskeletal protein that regulates cellular processes and Wnt/β-catenin pathway, an essential signaling pathway for osteoblasts. However, the relationship between MACF1 expression and mechanical unloading, and the function and the associated mechanisms of MACF1 in regulating osteoblast proliferation are unclear. This study investigated effects of mechanical unloading on MACF1 expression levels in cultured MC3T3-E1 osteoblastic cells and in femurs of mice with hind limb unloading; and it also examined the role and potential action mechanisms of MACF1 in osteoblast proliferation in MACF1-knockdown, overexpressed or control MC3T3-E1 cells treated with or without the mechanical unloading condition. Results showed that the mechanical unloading condition inhibited osteoblast proliferation and MACF1 expression in MC3T3-E1 osteoblastic cells and mouse femurs. MACF1 knockdown decreased osteoblast proliferation, while MACF1 overexpression increased it. The inhibitory effect of mechanical unloading on osteoblast proliferation also changed with MACF1 expression levels. Furthermore, MACF1 was found to enhance β-catenin expression and activity, and mechanical unloading decreased β-catenin expression through MACF1. Moreover, β-catenin was found an important regulator of osteoblast proliferation, as its preservation by treatment with its agonist lithium attenuated the inhibitory effects of MACF1-knockdown or mechanical unloading on osteoblast proliferation. Taken together, mechanical unloading decreases MACF1 expression, and MACF1 up-regulates osteoblast proliferation through enhancing β-catenin signaling. This study has thus provided a mechanism for mechanical unloading-induced inhibited osteoblast proliferation. © 2017 Wiley Periodicals, Inc.

Rac1 and Cdc42 GTPases regulate shear stress-driven β-catenin signaling in osteoblasts

International Nuclear Information System (INIS)

Wan, Qiaoqiao; Cho, Eunhye; Yokota, Hiroki; Na, Sungsoo

2013-01-01

Highlights: •Shear stress increased TCF/LEF activity and stimulated β-catenin nuclear localization. •Rac1, Cdc42, and RhoA displayed distinct dynamic activity patterns under flow. •Rac1 and Cdc42, but not RhoA, regulate shear stress-driven TCF/LEF activation. •Cytoskeleton did not significantly affect shear stress-induced TCF/LEF activation. -- Abstract: Beta-catenin-dependent TCF/LEF (T-cell factor/lymphocyte enhancing factor) is known to be mechanosensitive and an important regulator for promoting bone formation. However, the functional connection between TCF/LEF activity and Rho family GTPases is not well understood in osteoblasts. Herein we investigated the molecular mechanisms underlying oscillatory shear stress-induced TCF/LEF activity in MC3T3-E1 osteoblast cells using live cell imaging. We employed fluorescence resonance energy transfer (FRET)-based and green fluorescent protein (GFP)-based biosensors, which allowed us to monitor signal transduction in living cells in real time. Oscillatory (1 Hz) shear stress (10 dynes/cm 2 ) increased TCF/LEF activity and stimulated translocation of β-catenin to the nucleus with the distinct activity patterns of Rac1 and Cdc42. The shear stress-induced TCF/LEF activity was blocked by the inhibition of Rac1 and Cdc42 with their dominant negative mutants or selective drugs, but not by a dominant negative mutant of RhoA. In contrast, constitutively active Rac1 and Cdc42 mutants caused a significant enhancement of TCF/LEF activity. Moreover, activation of Rac1 and Cdc42 increased the basal level of TCF/LEF activity, while their inhibition decreased the basal level. Interestingly, disruption of cytoskeletal structures or inhibition of myosin activity did not significantly affect shear stress-induced TCF/LEF activity. Although Rac1 is reported to be involved in β-catenin in cancer cells, the involvement of Cdc42 in β-catenin signaling in osteoblasts has not been identified. Our findings in this study demonstrate

Rac1 and Cdc42 GTPases regulate shear stress-driven β-catenin signaling in osteoblasts

Energy Technology Data Exchange (ETDEWEB)

Wan, Qiaoqiao; Cho, Eunhye [Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States); Yokota, Hiroki [Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States); Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Na, Sungsoo, E-mail: sungna@iupui.edu [Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States)

2013-04-19

Highlights: •Shear stress increased TCF/LEF activity and stimulated β-catenin nuclear localization. •Rac1, Cdc42, and RhoA displayed distinct dynamic activity patterns under flow. •Rac1 and Cdc42, but not RhoA, regulate shear stress-driven TCF/LEF activation. •Cytoskeleton did not significantly affect shear stress-induced TCF/LEF activation. -- Abstract: Beta-catenin-dependent TCF/LEF (T-cell factor/lymphocyte enhancing factor) is known to be mechanosensitive and an important regulator for promoting bone formation. However, the functional connection between TCF/LEF activity and Rho family GTPases is not well understood in osteoblasts. Herein we investigated the molecular mechanisms underlying oscillatory shear stress-induced TCF/LEF activity in MC3T3-E1 osteoblast cells using live cell imaging. We employed fluorescence resonance energy transfer (FRET)-based and green fluorescent protein (GFP)-based biosensors, which allowed us to monitor signal transduction in living cells in real time. Oscillatory (1 Hz) shear stress (10 dynes/cm{sup 2}) increased TCF/LEF activity and stimulated translocation of β-catenin to the nucleus with the distinct activity patterns of Rac1 and Cdc42. The shear stress-induced TCF/LEF activity was blocked by the inhibition of Rac1 and Cdc42 with their dominant negative mutants or selective drugs, but not by a dominant negative mutant of RhoA. In contrast, constitutively active Rac1 and Cdc42 mutants caused a significant enhancement of TCF/LEF activity. Moreover, activation of Rac1 and Cdc42 increased the basal level of TCF/LEF activity, while their inhibition decreased the basal level. Interestingly, disruption of cytoskeletal structures or inhibition of myosin activity did not significantly affect shear stress-induced TCF/LEF activity. Although Rac1 is reported to be involved in β-catenin in cancer cells, the involvement of Cdc42 in β-catenin signaling in osteoblasts has not been identified. Our findings in this study demonstrate

ICAT: Integrating data infrastructure for facilities based science

International Nuclear Information System (INIS)

Flannery, Damian; Matthews, Brian; Griffin, Tom; Bicarregui, Juan; Gleaves, Michael; Lerusse, Laurent; Downing, Roger; Ashton, Alun; Sufi, Shoaib; Drinkwater, Glen; Kleese van Dam, Kerstin

2009-01-01

ICAT: Integrating data infrastructure for facilities based science Damian Flannery, Brian Matthews, Tom Griffin, Juan Bicarregui, Michael Gleaves, Laurent Lerusse, Roger Downing, Alun Ashton, Shoaib Sufi, Glen Drinkwater, Kerstin Kleese Abstract Scientific facilities, in particular large-scale photon and neutron sources, have demanding requirements to manage the increasing quantities of experimental data they generate in a systematic and secure way. In this paper, we describe the ICAT infrastructure for cataloguing facility generated experimental data which has been in development within STFC and DLS for several years. We consider the factors which have influenced its design and describe its architecture and metadata model, a key tool in the management of data. We go on to give an outline of its current implementation and use, with plans for its future development.

Crosstalk between a nuclear receptor and beta-catenin signaling decides cell fates in the C. elegans somatic gonad

Czech Academy of Sciences Publication Activity Database

Asahina, Masako; Valenta, Tomáš; Šilhánková, M.; Kořínek, Vladimír; Jindra, Marek

2006-01-01

Roč. 11, č. 2 (2006), s. 203-211 ISSN 1534-5807 R&D Projects: GA AV ČR KJB5022303; GA ČR GD524/03/H133; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50070508; CEZ:AV0Z50520514 Keywords : nuclear receptor * beta-catenin signaling * Caenorhabditis elegans Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.523, year: 2006

Cyclin G2 suppresses estrogen-mediated osteogenesis through inhibition of Wnt/β-catenin signaling.

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Jinlan Gao

Full Text Available Estrogen plays an important role in the maintenance of bone formation, and deficiency in the production of estrogen is directly linked to postmenopausal osteoporosis. To date, the underlying mechanisms of estrogen-mediated osteogenic differentiation are not well understood. In this study, a pluripotent mesenchymal precursor cell line C2C12 was used to induce osteogenic differentiation and subjected to detection of gene expressions or to manipulation of cyclin G2 expressions. C57BL/6 mice were used to generate bilateral ovariectomized and sham-operated mice for analysis of bone mineral density and protein expression. We identified cyclin G2, an unconventional member of cyclin, is involved in osteoblast differentiation regulated by estrogen in vivo and in vitro. In addition, the data showed that ectopic expression of cyclin G2 suppressed expression of osteoblast transcription factor Runx2 and osteogenic differentiation marker genes, as well as ALP activity and in vitro extracellular matrix mineralization. Mechanistically, Wnt/β-catenin signaling pathway is essential for cyclin G2 to inhibit osteogenic differentiation. To the best of our knowledge, the current study presents the first evidence that cyclin G2 serves as a negative regulator of both osteogenesis and Wnt/β-catenin signaling. Most importantly, the basal and 17β-estradiol-induced osteogenic differentiation was restored by overexpression of cyclin G2. These results taken together suggest that cyclin G2 may function as an endogenous suppressor of estrogen-induced osteogenic differentiation through inhibition of Wnt/β-catenin signaling.

Tob1 induces apoptosis and inhibits proliferation, migration and invasion of gastric cancer cells by activating Smad4 and inhibiting β‑catenin signaling.

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Kundu, Juthika; Wahab, S M Riajul; Kundu, Joydeb Kumar; Choi, Yoon-La; Erkin, Ozgur Cem; Lee, Hun Seok; Park, Sang Gyu; Shin, Young Kee

2012-09-01

Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

B-cell translocation gene 3 overexpression inhibits proliferation and invasion of colorectal cancer SW480 cells via Wnt/β-catenin signaling pathway.

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Mao, D; Qiao, L; Lu, H; Feng, Y

2016-01-01

Increasing evidences have shown that B-cell translocation gene 3 (BTG3) inhibits metastasis of multiple cancer cells. However, the role of BTG3 in colorectal cancer (CRC) and its possible mechanism have not yet been reported. In our study, we evaluated BTG3 expression in several CRC cell lines. Then, pcDNA3.1-BTG3 was transfected into SW480 cells. We found that BTG3 was upregulated in SW480 cells after overexpression plasmid transfection. BTG3 overexpression significantly inhibited cell growth and decreased PCNA (proliferating cell nuclear antigen) and Ki67 levels. BTG3 overexpression markedly downregulated Cyclin D1 and Cyclin E1 levels, whereas elevated p27. Overexpression of BTG3 arrested the cell cycle at G1 phase, which was abrogated by p27 silencing. Furthermore, migration, invasion and EMT of SW480 cells were significantly suppressed by BTG3 overexpression. Further investigations showed the inhibition of Wnt/β-catenin signaling pathway. We then used GSK3β specific inhibitor SB-216763 to activate the Wnt/β-catenin signaling pathway. We found that Wnt/β-catenin signaling pathway activation reversed the effect of BTG3 overexpression on cell proliferation, cell cycle progression, invasion and EMT. In conclusion, BTG3 overexpression inhibited cell growth, induced cell cycle arrest and suppressed the metastasis of SW480 cells via the Wnt/β-catenin signaling pathway. BTG3 may be considered as a therapeutic target in CRC treatment.

Reappraisal of mesenchymal chondrosarcoma: novel morphologic observations of the hyaline cartilage and endochondral ossification and beta-catenin, Sox9, and osteocalcin immunostaining of 22 cases.

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Fanburg-Smith, Julie C; Auerbach, Aaron; Marwaha, Jayson S; Wang, Zengfeng; Rushing, Elisabeth J

2010-05-01

Mesenchymal chondrosarcoma, a rare malignant round cell and hyaline cartilage tumor, is most commonly intraosseous but can occur in extraskeletal sites. We intensively observed the morphology and applied Sox9 (master regulator of chondrogenesis), beta-catenin (involved in bone formation, thought to inhibit chondrogenesis in a Sox9-dependent manner), and osteocalcin (a marker for osteoblastic phenotype) to 22 central nervous system and musculoskeletal mesenchymal chondrosarcoma. Cases of mesenchymal chondrosarcoma were retrieved and reviewed from our files. Immunohistochemistry and follow-up were obtained on mesenchymal chondrosarcoma and tumor controls. Twenty-two mesenchymal chondrosarcomas included 5 central nervous system (all female; mean age, 30.2; mean size, 7.8 cm; in frontal lobe [n = 4] and spinal cord [n = 1]) and 17 musculoskeletal (female-male ratio, 11:6; mean age, 31.1; mean size, 6.2 cm; 3 each of humerus and vertebrae; 2 each of pelvis, rib, tibia, neck soft tissue; one each of femur, unspecified bone, and elbow soft tissue). The hyaline cartilage in most tumors revealed a consistent linear progression of chondrocyte morphology, from resting to proliferating to hypertrophic chondrocytes. Sixty-seven percent of cases demonstrated cell death and acquired osteoblastic phenotype, cells positive for osteocalcin at the site of endochondral ossification. Small round cells of mesenchymal chondrosarcoma were negative for osteocalcin. SOX9 was positive in both components of 21 of 22 cases of mesenchymal chondrosarcoma. beta-Catenin highlighted rare nuclei at the interface between round cells and hyaline cartilage in 35% cases. Control skull and central nervous system cases were compared, including chondrosarcomas and small cell osteosarcoma, the latter positive for osteocalcin in small cells. Mesenchymal chondrosarcoma demonstrates centrally located hyaline cartilage with a linear progression of chondrocytes from resting to proliferative to hypertrophic

C/EBPα Short-Activating RNA Suppresses Metastasis of Hepatocellular Carcinoma through Inhibiting EGFR/β-Catenin Signaling Mediated EMT.

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Hongbo Huan

Full Text Available Hepatocellular carcinoma is associated with high mortality, and tumor metastasis is an important reason for poor prognosis. However, metastasis has not been effectively prevented in clinical therapy and the mechanisms underlying metastasis have not been fully characterized. CCAAT/enhancer-binding protein-α (C/EBPα is a transcriptional regulator with an essential role in tumor metastasis. We used short-activating RNAs (saRNA to enhance expression of C/EBPα. Intravenous injection of C/EBPα-saRNA in a nude mouse liver orthotopic xenograft tumor model inhibited intrahepatic and distant metastasis. C/EBPα-saRNA-treated mice showed increased serum levels of albumin and decreased alanine aminotransferase (ALT, glutamic-oxalacetic transaminase (AST, indicating a role of C/EBPα in improving liver function. Migration and invasion were inhibited in hepatoma cell lines transfected with C/EBPα-saRNA. We also observed an inhibition of epithelial-mesenchymal transition (EMT and suppression of epidermal growth factor receptor (EGFR, EGFR phosphorylation, and β-catenin in C/EBPa-saRNA-transfected cells. Our results suggested that C/EBPα-saRNA successfully inhibited HCC metastasis by inhibiting EGFR/β-catenin signaling pathway mediated EMT in vitro and in vivo.

NAMMA DC-8 NAVIGATION AND HOUSEKEEPING (ICATS) V1

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National Aeronautics and Space Administration — The NAMMA DC-8 Information Collection and Transmission System (ICATS) is designed to: 1) interface and process avionics and environmental paramaters from the...

Negative regulation of β-catenin/Tcf signaling by naringenin in AGS gastric cancer cell

International Nuclear Information System (INIS)

Lee, Ju Hyung; Park, Chi Hoon; Jung, Kyung Chae; Rhee, Ho Sung; Yang, Chul Hak

2005-01-01

Functional activation of β-catenin/Tcf signaling plays an important role in early events in carcinogenesis. We examined the effect of naringenin against β-catenin/Tcf signaling in gastric cancer cells. Reporter gene assay showed that naringenin inhibited β-catenin/Tcf signaling efficiently. In addition, the inhibition of β-catenin/Tcf signaling by naringenin in HEK293 cells transiently transfected with constitutively mutant β-catenin gene, whose product is not phosphorylated by GSK3β, indicates that its inhibitory mechanism was related to β-catenin itself or downstream components. To investigate the precise inhibitory mechanism, we performed immunofluorescence, Western blot, and EMSA. As a result, our data revealed that the β-catenin distribution and the levels of nuclear β-catenin and Tcf-4 proteins were unchanged after naringenin treatment. Moreover, the binding activities of Tcf complexes to consensus DNA were not affected by naringenin. Taken together, these data suggest that naringenin inhibits β-catenin/Tcf signaling in gastric cancer with unknown mechanisms

Functional interaction between beta-catenin and FOXO in oxidative stress signaling

NARCIS (Netherlands)

Essers, MAG; de Vries-Smits, LMM; Barker, N; Polderman, PE; Burgering, BMT; Korswagen, HC

2005-01-01

β-Catenin is a multifunctional protein that mediates Writ signaling by binding to members of the T cell factor (TCF) family of transcription factors. Here, we report an evolutionarily conserved interaction of β-catenin with FOXO transcription factors, which are regulated by insulin and oxidative

β-catenin at the centrosome: discrete pools of β-catenin communicate during mitosis and may co-ordinate centrosome functions and cell cycle progression.

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Mbom, Bertrade C; Nelson, W James; Barth, Angela

2013-09-01

Beta-catenin is a multifunctional protein with critical roles in cell-cell adhesion, Wnt-signaling and the centrosome cycle. Whereas the roles of β-catenin in cell-cell adhesion and Wnt-signaling have been studied extensively, the mechanism(s) involving β-catenin in centrosome functions are poorly understood. β-Catenin localizes to centrosomes and promotes mitotic progression. NIMA-related protein kinase 2 (Nek2), which stimulates centrosome separation, binds to and phosphorylates β-catenin. β-Catenin interacting proteins involved in Wnt signaling such as adenomatous polyposis coli, Axin, and GSK3β, are also localized at centrosomes and play roles in promoting mitotic progression. Additionally, proteins associated with cell-cell adhesion sites, such as dynein, regulate mitotic spindle positioning. These roles of proteins at the cell cortex and Wnt signaling that involve β-catenin indicate a cross-talk between different sub-cellular sites in the cell at mitosis, and that different pools of β-catenin may co-ordinate centrosome functions and cell cycle progression. © 2013 WILEY Periodicals, Inc.

Inhibition of Wnt/β-catenin signaling by a soluble collagen-derived frizzled domain interacting with Wnt3a and the receptors frizzled 1 and 8.

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Ismaïl Hendaoui

Full Text Available The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs, which have a cysteine-rich domain (CRD structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18 inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth.

β-Catenin transcriptional activity is minimal in canine osteosarcoma and its targeted inhibition results in minimal changes to cell line behaviour.

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Piskun, Caroline M; Stein, Timothy J

2016-06-01

Canine osteosarcoma (OS) is an aggressive malignancy associated with poor outcomes. Therapeutic improvements are likely to develop from an improved understanding of signalling pathways contributing to OS development and progression. The Wnt signalling pathway is of interest for its role in osteoblast differentiation, its dysregulation in numerous cancer types, and the relative frequency of cytoplasmic accumulation of β-catenin in canine OS. This study aimed to determine the biological impact of inhibiting canonical Wnt signalling in canine OS, by utilizing either β-catenin siRNA or a dominant-negative T-cell factor (TCF) construct. There were no consistent, significant changes in cell line behaviour with either method compared to parental cell lines. Interestingly, β-catenin transcriptional activity was three-fold higher in normal canine primary osteoblasts compared to canine OS cell lines. These results suggest canonical Wnt signalling is minimally active in canine OS and its targeted inhibition is not a relevant therapeutic strategy. © 2013 John Wiley & Sons Ltd.

Ectopic activation of Wnt/beta-catenin sgnaling in lens fiber cells results in cataract formation and aberrant fiber cell differentiation

Czech Academy of Sciences Publication Activity Database

Antošová, Barbora; Smolíková, Jana; Bořkovcová, Romana; Strnad, Hynek; Láchová, Jitka; Machoň, Ondřej; Kozmik, Zbyněk

2013-01-01

Roč. 8, č. 10 (2013), e78279 E-ISSN 1932-6203 R&D Projects: GA ČR GAP305/11/2198; GA ČR GAP305/12/2042; GA MŠk(CZ) LK11214; GA MŠk EE2.3.30.0027 Institutional support: RVO:68378050 Keywords : beta-catenin signaling * cataract * cell differentiation * lens * transcription factor * cyclin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.534, year: 2013

Long non-coding RNA MEG3 inhibits the proliferation and metastasis of oral squamous cell carcinoma by regulating the WNT/β-catenin signaling pathway.

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Liu, Zongxiang; Wu, Cui; Xie, Nina; Wang, Penglai

2017-10-01

This study aimed to investigate how long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) inhibits the growth and metastasis of oral squamous cell carcinoma (OSCC) by regulating WNT/β-catenin signaling pathway in order to explore the antitumor effect of MEG3 and to provide a potential molecular target for the treatment of OSCC. The RT-qPCR technique was used to quantitatively analyze the expression of MEG3 in cancer and adjacent tissues collected from the patients after surgery. Using the Lipofectamine method, the MEG3 overexpression vector and the siRNA interference vector were constructed and transfected into SCC15 and Cal27 cells, respectively, followed by cell proliferation, apoptosis and metastasis analyses. The semi-quantitative analysis of the expression of the β-catenin protein in transfected cells was performed by the western blot analysis, and the activity of the WNT/β-catenin signaling pathway was analyzed using the TOP/FOP flash reporters. In addition, the cells were treated with decitabine to investigate the correlation between the MEG3 expression and the DNA methylation. Results showed that the expression level of MEG3 was significantly decreased in OSCC (psuppressor by inhibiting the WNT/β-catenin signaling pathway. In addition, the expression of the MEG3 was significantly affected by the degree of DNA methylation. It was concluded that the lncRNA MEG3 can inhibit the growth and metastasis of OSCC by negatively regulating the WNT/β-catenin signaling pathway.

TGF-β prevents phosphate-induced osteogenesis through inhibition of BMP and Wnt/β-catenin pathways.

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Fátima Guerrero

Full Text Available BACKGROUND: Transforming growth factor-β (TGF-β is a key cytokine during differentiation of mesenchymal stem cells (MSC into vascular smooth muscle cells (VSMC. High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. RESULTS: Our results showed that TGF-β induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22α, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/β-catenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-β to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-β pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/β-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. CONCLUSIONS: Full VSMC differentiation induced by TGF-β may not be achieved when extracellular phosphate levels are high. Moreover, TGF-β prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/β-catenin pathway.

The EIPeptiDi tool: enhancing peptide discovery in ICAT-based LC MS/MS experiments

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Tradigo Giuseppe

2007-07-01

Full Text Available Abstract Background Isotope-coded affinity tags (ICAT is a method for quantitative proteomics based on differential isotopic labeling, sample digestion and mass spectrometry (MS. The method allows the identification and relative quantification of proteins present in two samples and consists of the following phases. First, cysteine residues are either labeled using the ICAT Light or ICAT Heavy reagent (having identical chemical properties but different masses. Then, after whole sample digestion, the labeled peptides are captured selectively using the biotin tag contained in both ICAT reagents. Finally, the simplified peptide mixture is analyzed by nanoscale liquid chromatography-tandem mass spectrometry (LC-MS/MS. Nevertheless, the ICAT LC-MS/MS method still suffers from insufficient sample-to-sample reproducibility on peptide identification. In particular, the number and the type of peptides identified in different experiments can vary considerably and, thus, the statistical (comparative analysis of sample sets is very challenging. Low information overlap at the peptide and, consequently, at the protein level, is very detrimental in situations where the number of samples to be analyzed is high. Results We designed a method for improving the data processing and peptide identification in sample sets subjected to ICAT labeling and LC-MS/MS analysis, based on cross validating MS/MS results. Such a method has been implemented in a tool, called EIPeptiDi, which boosts the ICAT data analysis software improving peptide identification throughout the input data set. Heavy/Light (H/L pairs quantified but not identified by the MS/MS routine, are assigned to peptide sequences identified in other samples, by using similarity criteria based on chromatographic retention time and Heavy/Light mass attributes. EIPeptiDi significantly improves the number of identified peptides per sample, proving that the proposed method has a considerable impact on the protein

Flurbiprofen benzyl nitrate (NBS-242) inhibits the growth of A-431 human epidermoid carcinoma cells and targets β-catenin.

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Nath, Niharika; Liu, Xiaoping; Jacobs, Lloydine; Kashfi, Khosrow

2013-01-01

The Wnt/β-catenin/T cell factor (TCF) signaling pathway is important in the development of nonmelanoma skin cancers (NMSCs). Nitric-oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) are chemopreventive agents consisting of a traditional NSAID attached to an NO-releasing moiety through a chemical spacer. Previously we showed that an aromatic spacer enhanced the potency of a particular NO-NSAID compared to an aliphatic spacer. We synthesized an NO-releasing NSAID with an aromatic spacer (flurbiprofen benzyl nitrate, NBS-242), and using the human skin cancer cell line A-431, we evaluated its effects on cell kinetics, Wnt/β-catenin, cyclin D1, and caspase-3. NBS-242 inhibited the growth of A-431 cancer cells, being ~15-fold more potent than flurbiprofen and up to 5-fold more potent than NO-flurbiprofen with an aliphatic spacer, the half maximal inhibitory concentrations (IC50) for growth inhibition being 60 ± 4 μM, 320 ± 20 μM, and 880 ± 65 μM for NBS-242, NO-flurbiprofen, and flurbiprofen, respectively. This effect was associated with inhibition of proliferation, accumulation of cells in the G0/G1 phase of the cell cycle, and an increase in apoptotic cell population. NBS-242 cleaved β-catenin both in the cytoplasm and the nucleus of A-431 cells. NBS-242 activated caspase-3 whose activation was reflected in the cleavage of procaspase-3. To test the functional consequence of β-catenin cleavage, we determined the expression of cyclin D1, a Wnt-response gene. NBS-242 reduced cyclin D1 levels in a concentration dependent manner. These findings establish a strong inhibitory effect of NBS-242 in A-431 human epidermoid carcinoma cells. NBS-242 modulates parameters that are important in determining cellular mass.

Protein kinase A antagonist inhibits β-catenin nuclear translocation, c-Myc and COX-2 expression and tumor promotion in ApcMin/+ mice

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Brudvik Kristoffer W

2011-12-01

Full Text Available Abstract Background The adenomatous polyposis coli (APC protein is part of the destruction complex controlling proteosomal degradation of β-catenin and limiting its nuclear translocation, which is thought to play a gate-keeping role in colorectal cancer. The destruction complex is inhibited by Wnt-Frz and prostaglandin E2 (PGE2 - PI-3 kinase pathways. Recent reports show that PGE2-induced phosphorylation of β-catenin by protein kinase A (PKA increases nuclear translocation indicating two mechanisms of action of PGE2 on β-catenin homeostasis. Findings Treatment of ApcMin/+ mice that spontaneously develop intestinal adenomas with a PKA antagonist (Rp-8-Br-cAMPS selectively targeting only the latter pathway reduced tumor load, but not the number of adenomas. Immunohistochemical characterization of intestines from treated and control animals revealed that expression of β-catenin, β-catenin nuclear translocation and expression of the β-catenin target genes c-Myc and COX-2 were significantly down-regulated upon Rp-8-Br-cAMPS treatment. Parallel experiments in a human colon cancer cell line (HCT116 revealed that Rp-8-Br-cAMPS blocked PGE2-induced β-catenin phosphorylation and c-Myc upregulation. Conclusion Based on our findings we suggest that PGE2 act through PKA to promote β-catenin nuclear translocation and tumor development in ApcMin/+ mice in vivo, indicating that the direct regulatory effect of PKA on β-catenin nuclear translocation is operative in intestinal cancer.

Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

Energy Technology Data Exchange (ETDEWEB)

Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

2009-12-25

Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

Aryl hydrocarbon receptor suppresses the osteogenesis of mesenchymal stem cells in collagen-induced arthritic mice through the inhibition of β-catenin

Energy Technology Data Exchange (ETDEWEB)

Tong, Yulong [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Niu, Menglin [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Department of Blood Transfusion, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Beijing 100142 (China); Du, Yuxuan; Mei, Wentong; Cao, Wei; Dou, Yunpeng [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Yu, Haitao [Department of Clinical Laboratory, The First Hospital of Lanzhou University, Lanzhou, Gansu Province 730000 (China); Du, Xiaonan [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Yuan, Huihui, E-mail: huihui_yuan@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Zhao, Wenming, E-mail: zhao-wenming@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China)

2017-01-15

The contributions of aryl hydrocarbon receptor (Ahr) to the pathogenesis of rheumatoid arthritis (RA), particularly bone loss, have not been clearly explored. The imbalance between osteoblasts and osteoclasts is a major reason for bone loss. The dysfunction of osteoblasts, which are derived from mesenchymal stem cells (MSCs), induced bone erosion occurs earlier and is characterized as more insidious. Here, we showed that the nuclear expression and translocation of Ahr were both significantly increased in MSCs from collagen-induced arthritis (CIA) mice. The enhanced Ahr suppressed the mRNA levels of osteoblastic markers including Alkaline phosphatase (Alp) and Runt-related transcription factor 2 (Runx2) in the differentiation of MSCs to osteoblasts in CIA. The 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated activation of Ahr dose-dependently suppressed the expression of osteoblastic markers. In addition, the expression of β-catenin was reduced in CIA MSCs compared with control, and the TCDD-mediated activation of the Ahr significantly inhibited β-catenin expression. The Wnt3a-induced the activation of Wnt/β-catenin pathway partly rescued the osteogenesis decline induced by TCDD. Taken together, these results indicate that activated Ahr plays a negative role in CIA MSCs osteogenesis, possibly by suppressing the expression of β-catenin. - Highlights: • The Ahr pathway displays an activated profile in CIA MSCs. • The activation of Ahr suppresses osteogenesis in CIA MSCs. • TCDD suppresses osteogenesis in a dose-dependent manner. • The activation of Ahr inhibits β-catenin expression to exacerbate bone erosion.

Cellular demise and inflammatory microglial activation during beta-amyloid toxicity are governed by Wnt1 and canonical signaling pathways.

Science.gov (United States)

Chong, Zhao Zhong; Li, Faqi; Maiese, Kenneth

2007-06-01

Initially described as a modulator of embryogenesis for a number of organ systems, Wnt1 has recently been linked to the development of several neurodegenerative disorders, none being of greater significance than Alzheimer's disease. We therefore examined the ability of Wnt1 to oversee vital pathways responsible for cell survival during beta-amyloid (Abeta1-42) exposure. Here we show that Wnt1 is critical for protection in the SH-SY5Y neuronal cell line against genomic DNA degradation, membrane phosphatidylserine (PS) exposure, and microglial activation, since these neuroprotective attributes of Wnt1 are lost during gene silencing of Wnt1 protein expression. Intimately tied to Wnt1 protection is the presence and activation of Akt1. Pharmacological inhibition of the PI 3-K pathway or gene silencing of Akt1 expression can abrogate the protective capacity of Wnt1. Closely aligned with Wnt1 and Akt1 are the integrated canonical pathways of synthase kinase-3beta (GSK-3beta) and beta-catenin. Through Akt1 dependent pathways, Wnt1 phosphorylates GSK-3beta and maintains beta-catenin integrity to insure its translocation from the cytoplasm to the nucleus to block apoptosis. Our work outlines a highly novel role for Wnt1 and its integration with Akt1, GSK-3beta, and beta-catenin to foster neuronal cell survival and repress inflammatory microglial activation that can identify new avenues of therapy against neurodegenerative disorders.

Analysing the impact of nucleo-cytoplasmic shuttling of β-catenin and its antagonists APC, Axin and GSK3 on Wnt/β-catenin signalling.

Science.gov (United States)

Schmitz, Yvonne; Rateitschak, Katja; Wolkenhauer, Olaf

2013-11-01

destruction complex inhibition, we show that the [β-catenin/TCF] concentration is more effectively enhanced by inhibition of the kinase GSK3 rather than the binding of β-catenin to the destruction complex. © 2013 Elsevier Inc. All rights reserved.

Downregulation of adenomatous polyposis coli by microRNA-663 promotes odontogenic differentiation through activation of Wnt/beta-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae-Sung; Park, Min-Gyeong; Lee, Seul Ah; Park, Sun-Young; Kim, Heung-Joong; Yu, Sun-Kyoung; Kim, Chun Sung; Kim, Su-Gwan; Oh, Ji-Su; You, Jae-Seek; Kim, Jin-Soo; Seo, Yo-Seob [Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 501-759 (Korea, Republic of); Chun, Hong Sung [Department of Biomedical Science, Chosun University, Gwangju 501-759 (Korea, Republic of); Park, Joo-Cheol [Department of Oral Histology-Developmental Biology, School of Dentistry and Dental Research Institute, BK 21, Seoul National University, Seoul 110-749 (Korea, Republic of); Kim, Do Kyung, E-mail: kdk@chosun.ac.kr [Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 501-759 (Korea, Republic of)

2014-04-18

Highlights: • miR-663 is significantly up-regulated during MDPC-23 odontoblastic cell differentiation. • miR-663 accelerates mineralization in MDPC-23 odontoblastic cells without cell proliferation. • miR-663 promotes odontoblastic cell differentiation by targeting APC and activating Wnt/β-catenin signaling in MDPC-23 cells. - Abstract: MicroRNAs (miRNAs) regulate cell differentiation by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNAs in odontogenic differentiation is largely unknown. In this present study, we observed that the expression of miR-663 increased significantly during differentiation of MDPC-23 cells to odontoblasts. Furthermore, up-regulation of miR-663 expression promoted odontogenic differentiation and accelerated mineralization without proliferation in MDPC-23 cells. In addition, target gene prediction for miR-663 revealed that the mRNA of the adenomatous polyposis coli (APC) gene, which is associated with the Wnt/β-catenin signaling pathway, has a miR-663 binding site in its 3′-untranslated region (3′UTR). Furthermore, APC expressional was suppressed significantly by miR-663, and this down-regulation of APC expression triggered activation of Wnt/β-catenin signaling through accumulation of β-catenin in the nucleus. Taken together, these findings suggest that miR-663 promotes differentiation of MDPC-23 cells to odontoblasts by targeting APC-mediated activation of Wnt/β-catenin signaling. Therefore, miR-663 can be considered a critical regulator of odontoblast differentiation and can be utilized for developing miRNA-based therapeutic agents.

[HSP90 Inhibitor 17-AAG Inhibits Multiple Myeloma Cell Proliferation by Down-regulating Wnt/β-Catenin Signaling Pathway].

Science.gov (United States)

Chen, Kan-Kan; He, Zheng-Mei; Ding, Bang-He; Chen, Yue; Zhang, Li-Juan; Yu, Liang; Gao, Jian

2016-02-01

To investigate the inhibitory effect of HSP90 inhibitory 17-AAG on proliferation of multiple myeloma cells and its main mechanism. The multiple myeloma cells U266 were treated with 17-AAG of different concentrations (200, 400, 600 and 800 nmol/L) for 24, 48, and 72 hours respectively, then the proliferation rate, expression levels of β-catenin and C-MYC protein, as well as cell cycle of U266 cells were treated with 17-AAG and were detected by MTT method, Western blot and flow cytometry, respectively. The 17-AAG showed inhibitory effect on the proliferation of U266 cells in dose- and time-depetent manners (r = -0.518, P AAG displayed no inhibitory effect on proliferation of U266 cells (P > 0.05). The result of culturing U266 cells for 72 hours by 17-AAG of different concentrations showed that the more high of 17-AAG concentration, the more low level of β-catenin and C-MYC proteins (P AAG concentration, the more high of cell ratio in G1 phase (P AAG, the more long time of culture, the more high of cell ratio in G1 phase (P AAG can inhibit the proliferation of multiple myeloma cells, the down-regulation of Wnt/β-catenin signaling pathway and inhibition of HSP90 expression may be the main mechnisms of 17-AAG effect.

Astragaloside IV Downregulates β-Catenin in Rat Keratinocytes to Counter LiCl-Induced Inhibition of Proliferation and Migration

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Fu-Lun Li

2012-01-01

Full Text Available Re-epithelialization is a crucial step towards wound healing. The traditional Chinese medicine, Astragalus membranaceus (Fisch Bge, has been used for hundreds of years for many kinds of ulcerated wounds. Recent research has identified the active compound in this drug as astragaloside IV (AS-IV, but the underlying molecular mechanisms of its therapeutic action on keratinocytes remain poorly understood. In this study, we used an in vitro model of ulcer-like wound processes, lithium chloride (LiCl-induced cultured mouse keratinocytes, to investigate the effects of AS-IV treatment. The effects on cell proliferation were evaluated by the MTS/PMS colorimetric assay, effects on cell migration were determined by a wound-healing scratch experiment, effects on the cell cycle were analyzed by flow cytometry, and effects on protein expression were analyzed by immunoblotting and immunofluorescence. LiCl strongly inhibited cell proliferation and migration, up-regulated β-catenin expression, and down-regulated proliferating cell nuclear antigen (PCNA expression. AS-IV treatment attenuat the inhibition of proliferation and migration, significantly reducing the enhanced β-catenin expression, and recovering PCNA and β-tubulin expression. Thus, AS-IV mediates mouse keratinocyte proliferation and migration via regulation of the Wnt signaling pathway. Down-regulating β-catenin to increase keratinocyte migration and proliferation is one mechanism by which AS-IV can promote ulcerated wound healing.

IWR-1, a tankyrase inhibitor, attenuates Wnt/β-catenin signaling in cancer stem-like cells and inhibits in vivo the growth of a subcutaneous human osteosarcoma xenograft.

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Martins-Neves, Sara R; Paiva-Oliveira, Daniela I; Fontes-Ribeiro, Carlos; Bovée, Judith V M G; Cleton-Jansen, Anne-Marie; Gomes, Célia M F

2018-02-01

Wnt/β-catenin or canonical Wnt signaling pathway regulates the self-renewal of cancer stem-like cells (CSCs) and is involved in tumor progression and chemotherapy resistance. Previously, we reported that this pathway is activated in a subset of osteosarcoma CSCs and that doxorubicin induced stemness properties in differentiated cells through Wnt/β-catenin activation. Here, we investigated whether pharmacological Wnt/β-catenin inhibition, using a tankyrase inhibitor (IWR-1), might constitute a strategy to target CSCs and improve chemotherapy efficacy in osteosarcoma. IWR-1 was specifically cytotoxic for osteosarcoma CSCs. IWR-1 impaired spheres' self-renewal capacity by compromising landmark steps of the canonical Wnt signaling, namely translocation of β-catenin to the nucleus and subsequent TCF/LEF activation and expression of Wnt/β-catenin downstream targets. IWR-1 also hampered the activity and expression of key stemness-related markers. In vitro, IWR-1 induced apoptosis of osteosarcoma spheres and combined with doxorubicin elicited synergistic cytotoxicity, reversing spheres' resistance to this drug. In vivo, IWR-1 co-administration with doxorubicin substantially decreased tumor progression, associated with specific down-regulation of TCF/LEF transcriptional activity, nuclear β-catenin and expression of the putative CSC marker Sox2. We suggest that targeting the Wnt/β-catenin pathway can eliminate CSCs populations in osteosarcoma. Combining conventional chemotherapy with Wnt/β-catenin inhibition may ameliorate therapeutic outcomes, by eradicating the aggressive osteosarcoma CSCs and reducing drug resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

Knockdown of long non-coding RNA Taurine Up-Regulated 1 inhibited doxorubicin resistance of bladder urothelial carcinoma via Wnt/β-catenin pathway.

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Xie, Dalong; Zhang, Hui; Hu, Xuanhao; Shang, Chao

2017-10-24

In genitourinary system, bladder cancer (BC) is the most common and lethal malignant tumor, which most common type is bladder urothelial carcinoma (BUC). Long non-coding RNA (lncRNA) Taurine Up-Regulated 1 (TUG1) gene is high-expressed in several malignant tumors, including BC. In this study, over-expression of TUG1 was found in BUC tissues and cell line resistant to doxorubicin (Dox). Knockdown of TUG1 inhibited the Dox resistance and promoted the cytotoxicity induced by Dox in T24/Dox cells. TUG1 knockdown also depressed the Wnt/β-catenin pathway, and the activation the Wnt/β-catenin pathway partly reversed the inhibitory effects of TUG1 knockdown on Dox resistance in T24/Dox cells. In conclusion, up-regulation of lncRNA TUG1 was related with the poor response of BUC patients to Dox chemotherapy, knockdown of TUG1 inhibited the Dox resistance of BUC cells via Wnt/β-catenin pathway. These findings might assist in the discovery of novel potential diagnostic and therapeutic target for BUC, thereby improve the effects of clinical treatment in patients.

Curcumin induces cleavage of β-catenin by activation of capases ...

African Journals Online (AJOL)

STORAGESEVER

2009-10-19

Oct 19, 2009 ... When the Wnt pathway is activated, GSK3β is inhibited and β-catenin is not phos- phorylated any more and the level of cellular β-catenin increases. Free β-catenin can translocate to the nucleus, forming a complex with T-cell factor 4 (Tcf-4). This com- plex then binds DNA and induces the expression of.

Flurbiprofen benzyl nitrate (NBS-242 inhibits the growth of A-431 human epidermoid carcinoma cells and targets ß-catenin

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Nath N

2013-05-01

Full Text Available Niharika Nath,1,2 Xiaoping Liu,3 Lloydine Jacobs,1 Khosrow Kashfi1,3 1Department of Physiology, Pharmacology, and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, New York, NY, USA; 2Department of Life Sciences, New York Institute of Technology, New York, NY, USA; 3Division of Cancer Prevention, Department of Medicine, Stony Brook University, Stony Brook, NY, USA Background: The Wnt/ß-catenin/T cell factor (TCF signaling pathway is important in the development of nonmelanoma skin cancers (NMSCs. Nitric-oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs are chemopreventive agents consisting of a traditional NSAID attached to an NO-releasing moiety through a chemical spacer. Previously we showed that an aromatic spacer enhanced the potency of a particular NO-NSAID compared to an aliphatic spacer. Methods: We synthesized an NO-releasing NSAID with an aromatic spacer (flurbiprofen benzyl nitrate, NBS-242, and using the human skin cancer cell line A-431, we evaluated its effects on cell kinetics, Wnt/ß-catenin, cyclin D1, and caspase-3. Results: NBS-242 inhibited the growth of A-431 cancer cells, being ~15-fold more potent than flurbiprofen and up to 5-fold more potent than NO-flurbiprofen with an aliphatic spacer, the half maximal inhibitory concentrations (IC50 for growth inhibition being 60 ± 4 µM, 320 ± 20 µM, and 880 ± 65 µM for NBS-242, NO-flurbiprofen, and flurbiprofen, respectively. This effect was associated with inhibition of proliferation, accumulation of cells in the G0/G1 phase of the cell cycle, and an increase in apoptotic cell population. NBS-242 cleaved ß-catenin both in the cytoplasm and the nucleus of A-431 cells. NBS-242 activated caspase-3 whose activation was reflected in the cleavage of procaspase-3. To test the functional consequence of ß-catenin cleavage, we determined the expression of cyclin D1, a Wnt-response gene. NBS-242 reduced cyclin D1 levels

Protein-bound polysaccharide from Phellinus linteus inhibits tumor growth, invasion, and angiogenesis and alters Wnt/β-catenin in SW480 human colon cancer cells

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Park Hae-Duck

2011-07-01

Full Text Available Abstract Background Polysaccharides extracted from the Phellinus linteus (PL mushroom are known to possess anti-tumor effects. However, the molecular mechanisms responsible for the anti-tumor properties of PL remain to be explored. Experiments were carried out to unravel the anticancer effects of PL. Methods The anti-cancer effects of PL were examined in SW480 colon cancer cells by evaluating cell proliferation, invasion and matrix metallo-proteinase (MMP activity. The anti-angiogenic effects of PL were examined by assessing human umbilical vein endothelial cell (HUVEC proliferation and capillary tube formation. The in vivo effect of PL was evaluated in an athymic nude mouse SW480 tumor engraft model. Results PL (125-1000 μg/mL significantly inhibited cell proliferation and decreased β-catenin expression in SW480 cells. Expression of cyclin D1, one of the downstream-regulated genes of β-catenin, and T-cell factor/lymphocyte enhancer binding factor (TCF/LEF transcription activity were also significantly reduced by PL treatment. PL inhibited in vitro invasion and motility as well as the activity of MMP-9. In addition, PL treatment inhibited HUVEC proliferation and capillary tube formation. Tumor growth of SW480 cells implanted into nude mice was significantly decreased as a consequence of PL treatment, and tumor tissues from treated animals showed an increase in the apoptotic index and a decrease in β-catenin expression. Moreover, the proliferation index and microvessel density were significantly decreased. Conclusions These data suggest that PL suppresses tumor growth, invasion, and angiogenesis through the inhibition of Wnt/β-catenin signaling in certain colon cancer cells.

GSK3β and β-Catenin Modulate Radiation Cytotoxicity in Pancreatic Cancer

Directory of Open Access Journals (Sweden)

Richard L. Watson

2010-05-01

Full Text Available BACKGROUND: Knowledge of factors and mechanisms contributing to the inherent radioresistance of pancreatic cancer may improve cancer treatment. Irradiation inhibits glycogen synthase kinase 3β (GSK3β by phosphorylation at serine 9. In turn, release of cytosolic membrane β-catenin with subsequent nuclear translocation promotes survival. Both GSK3β and β-catenin have been implicated in cancer cell proliferation and resistance to death. METHODS: We investigated pancreatic cancer cell survival after radiation in vitro and in vivo, with a particular focus on the role of the function of the GSK3β/β-catenin axis. RESULTS: Lithium chloride, RNAi-medicated silencing of GSK3β, or the expression of a kinase dead mutant GSK3β resulted in radioresistance of Panc1 and BxPC3 pancreatic cancer cells. Conversely, ectopic expression of a constitutively active form of GSK3β resulted in radiosensitization of Panc1 cells. GSK3β silencing increased radiation-induced β-catenin target gene expression asmeasured by studies of AXIN2 and LEF1 transcript levels. Western blot analysis of total and phosphorylated levels of GSK3β and β-catenin showed that GSK3β inhibition resulted in stabilization of β-catenin. Xenografts of both BxPC3 and Panc1 with targeted silencing of GSK3β exhibited radioresistance in vivo. Silencing of β-catenin resulted in radiosensitization, whereas a nondegradable β-catenin construct induced radioresistance. CONCLUSIONS: These data support the hypothesis that GSK3β modulates the cellular response to radiation in a β-catenin-dependent mechanism. Further understanding of this pathway may enhance the development of clinical trials combining drugs inhibiting β-catenin activation with radiation and chemotherapy in locally advanced pancreatic cancer.

Structure–activity studies of Wnt/β-catenin inhibition in the Niclosamide chemotype: Identification of derivatives with improved drug exposure

OpenAIRE

Mook, Robert A.; Wang, Jiangbo; Ren, Xiu-Rong; Chen, Minyong; Spasojevic, Ivan; Barak, Larry S.; Lyerly, H. Kim; Chen, Wei

2015-01-01

The Wnt signaling pathway plays a key role in regulation of organ development and tissue homeostasis. Dysregulated Wnt activity is one of the major underlying mechanisms responsible for many diseases including cancer. We previously reported the FDA-approved anthelmintic drug Niclosamide inhibits Wnt/β-catenin signaling and suppresses colon cancer cell growth in vitro and in vivo. Niclosamide is a multi-functional drug that possesses important biological activity in addition to inhibition of W...

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 induces apoptosis of human endometriotic cells through suppression of ERK1/2, AKT, NFkappaB, and beta-catenin pathways and activation of intrinsic apoptotic mechanisms.

Science.gov (United States)

Banu, Sakhila K; Lee, JeHoon; Speights, V O; Starzinski-Powitz, Anna; Arosh, Joe A

2009-08-01

Endometriosis is a benign chronic gynecological disease of reproductive-age women characterized by the presence of functional endometrial tissues outside the uterine cavity. It is an estrogen-dependent disease. Current treatment modalities to inhibit biosynthesis and actions of estrogen compromise menstruation, pregnancy, and the reproductive health of women and fail to prevent reoccurrence of disease. There is a critical need to identify new specific signaling modules for non-estrogen-targeted therapies for endometriosis. In our previous study, we reported that selective inhibition of cyclooxygenase-2 prevented survival, migration, and invasion of human endometriotic epithelial and stromal cells, which was due to decreased prostaglandin E(2) (PGE(2)) production. In this study, we determined mechanisms through which PGE(2) promoted survival of human endometriotic cells. Results of the present study indicate that 1) PGE(2) promotes survival of human endometriotic cells through EP2 and EP4 receptors by activating ERK1/2, AKT, nuclear factor-kappaB, and beta-catenin signaling pathways; 2) selective inhibition of EP2 and EP4 suppresses these cell survival pathways and augments interactions between proapoptotic proteins (Bax and Bad) and antiapoptotic proteins (Bcl-2/Bcl-XL), facilitates the release of cytochrome c, and thus activates caspase-3/poly (ADP-ribose) polymerase-mediated intrinsic apoptotic pathways; and 3) these PGE(2) signaling components are more abundantly expressed in ectopic endometriosis tissues compared with eutopic endometrial tissues during the menstrual cycle in women. These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential therapy, including nonestrogen target, to expand the spectrum of currently available treatment options for endometriosis in women.

Inhibition of transforming growth factor-beta1-induced signaling and epithelial-to-mesenchymal transition by the Smad-binding peptide aptamer Trx-SARA.

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Zhao, Bryan M; Hoffmann, F Michael

2006-09-01

Overexpression of the inhibitory Smad, Smad7, is used frequently to implicate the Smad pathway in cellular responses to transforming growth factor beta (TGF-beta) signaling; however, Smad7 regulates several other proteins, including Cdc42, p38MAPK, and beta-catenin. We report an alternative approach for more specifically disrupting Smad-dependent signaling using a peptide aptamer, Trx-SARA, which comprises a rigid scaffold, the Escherichia coli thioredoxin A protein (Trx), displaying a constrained 56-amino acid Smad-binding motif from the Smad anchor for receptor activation (SARA) protein. Trx-SARA bound specifically to Smad2 and Smad3 and inhibited both TGF-beta-induced reporter gene expression and epithelial-to-mesenchymal transition in NMuMG murine mammary epithelial cells. In contrast to Smad7, Trx-SARA had no effect on the Smad2 or 3 phosphorylation levels induced by TGF-beta1. Trx-SARA was primarily localized to the nucleus and perturbed the normal cytoplasmic localization of Smad2 and 3 to a nuclear localization in the absence of TGF-beta1, consistent with reduced Smad nuclear export. The key mode of action of Trx-SARA was to reduce the level of Smad2 and Smad3 in complex with Smad4 after TGF-beta1 stimulation, a mechanism of action consistent with the preferential binding of SARA to monomeric Smad protein and Trx-SARA-mediated disruption of active Smad complexes.

Smad7 induces tumorigenicity by blocking TGF-beta-induced growth inhibition and apoptosis.

Science.gov (United States)

Halder, Sunil K; Beauchamp, R Daniel; Datta, Pran K

2005-07-01

Smad proteins play a key role in the intracellular signaling of the transforming growth factor beta (TGF-beta) superfamily of extracellular polypeptides that initiate signaling to regulate a wide variety of biological processes. The inhibitory Smad, Smad7, has been shown to function as intracellular antagonists of TGF-beta family signaling and is upregulated in several cancers. To determine the effect of Smad7-mediated blockade of TGF-beta signaling, we have stably expressed Smad7 in a TGF-beta-sensitive, well-differentiated, and non-tumorigenic cell line, FET, that was derived from human colon adenocarcinoma. Smad7 inhibits TGF-beta-induced transcriptional responses by blocking complex formation between Smad 2/3 and Smad4. While Smad7 has no effect on TGF-beta-induced activation of p38 MAPK and ERK, it blocks the phosphorylation of Akt by TGF-beta and enhances TGF-beta-induced phosphorylation of c-Jun. FET cells expressing Smad7 show anchorage-independent growth and enhance tumorigenicity in athymic nude mice. Smad7 blocks TGF-beta-induced growth inhibition by preventing TGF-beta-induced G1 arrest. Smad7 inhibits TGF-beta-mediated downregulation of c-Myc, CDK4, and Cyclin D1, and suppresses the expression of p21(Cip1). As a result, Smad7 inhibits TGF-beta-mediated downregulation of Rb phosphorylation. Furthermore, Smad7 inhibits the apoptosis of these cells. Together, Smad7 may increase the tumorigenicity of FET cells by blocking TGF-beta-induced growth inhibition and by inhibiting apoptosis. Thus, this study provides a mechanism by which a portion of human colorectal tumors may become refractory to tumor-suppressive actions of TGF-beta that might result in increased tumorigenicity.

Roles of Wnt/β-catenin signaling in epithelial differentiation of mesenchymal stem cells

International Nuclear Information System (INIS)

Wang, Yajing; Sun, Zhaorui; Qiu, Xuefeng; Li, Yan; Qin, Jizheng; Han, Xiaodong

2009-01-01

Bone marrow-derived mesenchymal stem cells (MSCs) have been demonstrated to be able to differentiate into epithelial lineage, but the precise mechanisms controlling this process are unclear. Our aim is to explore the roles of Wnt/β-catenin in the epithelial differentiation of MSCs. Using indirect co-culture of rat MSCs with rat airway epithelial cells (RTE), MSCs expressed several airway epithelial markers (cytokeratin 18, tight junction protein occudin, cystic fibrosis transmembrance regulator). The protein levels of some important members in Wnt/β-catenin signaling were determined, suggested down-regulation of Wnt/β-catenin with epithelial differentiation of MSCs. Furthermore, Wnt3α can inhibit the epithelial differentiation of MSCs. A loss of β-catenin induced by Dickkopf-1 can enhance MSCs differentiation into epithelial cells. Lithium chloride transiently activated β-catenin expression and subsequently decreased β-catenin level and at last inhibited MSCs to differentiate into airway epithelium. Taken together, our study indicated that RTE cells can trigger epithelial differentiation of MSCs. Blocking Wnt/β-catenin signaling may promote MSCs to differentiate towards airway epithelial cells.

Leptin promotes osteoblast differentiation and mineralization of primary cultures of vascular smooth muscle cells by inhibiting glycogen synthase kinase (GSK)-3{beta}

Energy Technology Data Exchange (ETDEWEB)

Zeadin, Melec G.; Butcher, Martin K.; Shaughnessy, Stephen G. [Department of Medicine, McMaster University, Hamilton, ON (Canada); Thrombosis and Atherosclerosis Research Institute, Hamilton, ON (Canada); Werstuck, Geoff H., E-mail: Geoff.Werstuck@taari.ca [Department of Medicine, McMaster University, Hamilton, ON (Canada); Thrombosis and Atherosclerosis Research Institute, Hamilton, ON (Canada)

2012-09-07

Highlights: Black-Right-Pointing-Pointer Leptin promotes osteoblast differentiation of primary smooth muscle cells. Black-Right-Pointing-Pointer Leptin regulates the expression of genes involved in osteoblast differentiation. Black-Right-Pointing-Pointer Constitutively active GSK-3{beta} attenuates leptin-induced osteoblast differentiation. Black-Right-Pointing-Pointer This suggests that leptin signals through GSK-3{beta} to promote osteoblast differentiation. -- Abstract: In this study, we begin to investigate the underlying mechanism of leptin-induced vascular calcification. We found that treatment of cultured bovine aortic smooth muscle cells (BASMCs) with leptin (0.5-4 {mu}g/ml) induced osteoblast differentiation in a dose-dependent manner. Furthermore, we found that leptin significantly increased the mRNA expression of osteopontin and bone sialoprotein, while down-regulating matrix gla protein (MGP) expression in BASMCs. Key factors implicated in osteoblast differentiation, including members of the Wnt signaling pathway, were examined. Exposure to leptin enhanced phosphorylation of GSK-3{beta} on serine-9 thereby inhibiting activity and promoting the nuclear accumulation of {beta}-catenin. Transfection of BASMCs with an adenovirus that expressed constitutively active GSK-3{beta} (Ad-GSK-3{beta} S9A) resulted in a >2-fold increase in GSK-3{beta} activity and a significant decrease in leptin-induced alkaline phosphatase (ALP) activity. In addition, qRT-PCR analysis showed that GSK-3{beta} activation resulted in a significant decrease in the expression of osteopontin and bone sialoprotein, but a marked increase in MGP mRNA expression. When taken together, our results suggest a mechanism by which leptin promotes osteoblast differentiation and vascular calcification in vivo.

Interaction between Wnt/β-catenin and RAS-ERK pathways and an anti-cancer strategy via degradations of β-catenin and RAS by targeting the Wnt/β-catenin pathway.

Science.gov (United States)

Jeong, Woo-Jeong; Ro, Eun Ji; Choi, Kang-Yell

2018-01-01

Aberrant activation of the Wnt/β-catenin and RAS-extracellular signal-regulated kinase (ERK) pathways play important roles in the tumorigenesis of many different types of cancer, most notably colorectal cancer (CRC). Genes for these two pathways, such as adenomatous polyposis coli ( APC ) and KRAS are frequently mutated in human CRC, and involved in the initiation and progression of the tumorigenesis, respectively. Moreover, recent studies revealed interaction of APC and KRAS mutations in the various stages of colorectal tumorigenesis and even in metastasis accompanying activation of the cancer stem cells (CSCs). A key event in the synergistic cooperation between Wnt/β-catenin and RAS-ERK pathways is a stabilization of both β-catenin and RAS especially mutant KRAS by APC loss, and pathological significance of this was indicated by correlation of increased β-catenin and RAS levels in human CRC where APC mutations occur as high as 90% of CRC patients. Together with the notion of the protein activity reduction by lowering its level, inhibition of both β-catenin and RAS especially by degradation could be a new ideal strategy for development of anti-cancer drugs for CRC. In this review, we will discuss interaction between the Wnt/β-catenin and RAS-ERK pathways in the colorectal tumorigenesis by providing the mechanism of RAS stabilization by aberrant activation of Wnt/β-catenin. We will also discuss our small molecular anti-cancer approach controlling CRC by induction of specific degradations of both β-catenin and RAS via targeting Wnt/β-catenin pathway especially for the KYA1797K, a small molecule specifically binding at the regulator of G-protein signaling (RGS)-domain of Axin.

Inhibition of HIF-2.alpha. heterodimerization with HIF1.beta. (ARNT)

Science.gov (United States)

Bruick, Richard K.; Caldwell, Charles G.; Frantz, Doug E.; Gardner, Kevin H.; MacMillan, John B.; Scheuermann, Thomas H.; Tambar, Uttam K.

2017-09-12

Provided is a method of inhibiting heterodimerization of HIF-2.alpha. to HIF1.beta. (ARNT) comprising binding certain small molecules to the HIF-2.alpha. PAS-B domain cavity but not to HIF1.alpha. and inhibiting HIF-2.alpha. heterodimerization to HIF1.beta. (ARNT) but not inhibiting HIF1.alpha. heterodimerization to HIF1.beta. (ARNT). Those certain small molecules are also referenced synonymously as HIF2-HDI and HIF2.alpha. heterodimerization inhibitors and also simply as certain small molecules.

Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

International Nuclear Information System (INIS)

Li, Hua; Lee, Hwa Jin; Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young; Ryu, Jae-Ha

2014-01-01

Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer

Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

Energy Technology Data Exchange (ETDEWEB)

Li, Hua [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Lee, Hwa Jin [Department of Natural Medicine Resources, Semyung University, 65 Semyung-ro, Jecheon, Chungbuk 390-711 (Korea, Republic of); Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Ryu, Jae-Ha, E-mail: ryuha@sookmyung.ac.kr [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of)

2014-01-03

Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer.

beta-Chloro-L-alanine inhibition of the Escherichia coli alanine-valine transaminase.

OpenAIRE

Whalen, W A; Wang, M D; Berg, C M

1985-01-01

beta-Chloro-L-alanine, an amino acid analog which inhibits a number of enzymes, reversibly inhibited the Escherichia coli K-12 alanine-valine transaminase, transaminase C. This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine.

Sun-mediated mechanical LINC between nucleus and cytoskeleton regulates βcatenin nuclear access.

Science.gov (United States)

Uzer, Gunes; Bas, Guniz; Sen, Buer; Xie, Zhihui; Birks, Scott; Olcum, Melis; McGrath, Cody; Styner, Maya; Rubin, Janet

2018-06-06

βcatenin acts as a primary intracellular signal transducer for mechanical and Wnt signaling pathways to control cell function and fate. Regulation of βcatenin in the cytoplasm has been well studied but βcatenin nuclear trafficking and function remains unclear. In a previous study we showed that, in mesenchymal stem cells (MSC), mechanical blockade of adipogenesis relied on inhibition of βcatenin destruction complex element GSK3β (glycogen synthase kinase 3β) to increase nuclear βcatenin as well as the function of Linker of Cytoskeleton and Nucleoskeleton (LINC) complexes, suggesting that these two mechanisms may be linked. Here we show that shortly after inactivation of GSK3β due to either low intensity vibration (LIV), substrate strain or pharmacologic inhibition, βcatenin associates with the nucleoskeleton, defined as the insoluble nuclear fraction that provides structure to the integrated nuclear envelope, nuclear lamina and chromatin. Co-depleting LINC elements Sun-1 and Sun-2 interfered with both nucleoskeletal association and nuclear entry of βcatenin, resulting in decreased nuclear βcatenin levels. Our findings reveal that the insoluble structural nucleoskeleton actively participates in βcatenin dynamics. As the cytoskeleton transmits applied mechanical force to the nuclear surface to influence the nucleoskeleton and its LINC mediated interaction, our results suggest a pathway by which LINC mediated connectivity may play a role in signaling pathways that depend on nuclear access of βcatenin. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prognostic value of E-cadherin, beta-catenin, CD44v6, and HER2/neu in metastatic cutaneous adenocarcinoma.

Science.gov (United States)

Pozdnyakova, Olga; Hoang, Mai M P; Dresser, Karen A; Mahalingam, Meera

2009-08-01

Our recent experience with a patient developing cutaneous metastases within 3 months of diagnosis of esophageal adenocarcinoma suggests that altered expression of the cellular adhesion molecules, E-cadherin and CD44v6, may have had a role to play in the rapid onset of metastases. To corroborate these findings, we designed a cross-sectional study to investigate the expression of select molecules involved in the metastatic cascade. E-cadherin, beta-catenin, CD44v6, and HER2/neu immunohistochemical stains were performed on archival materials of metastatic adenocarcinoma to the skin from 27 patients and the available corresponding primary tumors in 10 patients. The primary sites included breast (n = 10; 37%), gastrointestinal tract (n = 10; 37%), ovary (n = 1; 4%), thyroid (n = 2; 7%), lung (n = 1; 4%), and unknown primary (n = 3; 11%). Expression of all markers was noted with the most significant increases observed in beta-catenin (26 of 27 cases; 96%), followed by CD44v6 (24 of 27 cases; 89%), E-cadherin (22 of 27 cases; 82%), and HER2/neu (11 of 27 cases; 41%). Contrasting expression of these molecules in the primary versus the metastatic tumors, enhanced expression of CD44v6 was observed in the cutaneous metastases relative to the primary in 6 of 10 (60%) cases. Of interest, 2 of these 6 cases (33%) also showed reduction in E-cadherin--a member of the cadherin family functioning as an invasion suppressor molecule. These findings reinforce the complexities of the metastatic cascade and imply that the variation in adhesive properties of tumor cells is, perhaps, a consequence of the difference in density of the molecules mediating this process.

The nuclear receptor NHR-25 cooperates with the Wnt/ .beta.-catenin asymmetry pathway to control differentiation of the T seam cell in C. elegans

Czech Academy of Sciences Publication Activity Database

Hajdušková, Martina; Jindra, Marek; Herman, M. A.; Asahina, Masako

2009-01-01

Roč. 122, č. 17 (2009), s. 3051-3060 ISSN 0021-9533 R&D Projects: GA ČR(CZ) GA204/07/0948; GA ČR(CZ) GD204/09/H058; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50070508 Keywords : nuclear receptor * Wnt /.beta.-catenin signaling * Caenorhabditis elegans Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.144, year: 2009

N-terminal nesprin-2 variants regulate β-catenin signalling

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qiuping; Minaisah, Rose-Marie; Ferraro, Elisa; Li, Chen; Porter, Lauren J.; Zhou, Can; Gao, Fang; Zhang, Junyi; Rajgor, Dipen; Autore, Flavia; Shanahan, Catherine M.; Warren, Derek T., E-mail: derek.warren@kcl.ac.uk

2016-07-15

The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity. - Highlights: • N-terminal nesprin-2 variants display cell specific expression patterns. • N-terminal spectrin repeats of nesprin-2 interact with β-catenin. • N-terminal nesprin-2 variants scaffold β-catenin at cell-cell junctions.. • Nesprin-2 variants play multiple roles in β-catenin signalling.

Combined inhibition of β-catenin and Bcr–Abl synergistically targets tyrosine kinase inhibitor-resistant blast crisis chronic myeloid leukemia blasts and progenitors in vitro and in vivo

Science.gov (United States)

Zhou, H; Mak, P Y; Mu, H; Mak, D H; Zeng, Z; Cortes, J; Liu, Q; Andreeff, M; Carter, B Z

2017-01-01

Tyrosine kinase inhibitor (TKI) resistance and progression to blast crisis (BC), both related to persistent β-catenin activation, remain formidable challenges for chronic myeloid leukemia (CML). We observed overexpression of β-catenin in BC-CML stem/progenitor cells, particularly in granulocyte–macrophage progenitors, and highest among a novel CD34+CD38+CD123hiTim-3hi subset as determined by CyTOF analysis. Co-culture with mesenchymal stromal cells (MSCs) induced the expression of β-catenin and its target CD44 in CML cells. A novel Wnt/β-catenin signaling modulator, C82, and nilotinib synergistically killed KBM5T315I and TKI-resistant primary BC-CML cells with or without BCR–ABL kinase mutations even under leukemia/MSC co-culture conditions. Silencing of β-catenin by short interfering RNA restored sensitivity of primary BCR–ABLT315I/E255V BC-CML cells to nilotinib. Combining the C82 pro-drug, PRI-724, with nilotinib significantly prolonged the survival of NOD/SCID/IL2Rγ null mice injected with primary BCR–ABLT315I/E255V BC-CML cells. The combined treatment selectively targeted CML progenitors and inhibited CD44, c-Myc, survivin, p-CRKL and p-STAT5 expression. In addition, pretreating primary BC-CML cells with C82, or the combination, but not with nilotinib alone, significantly impaired their engraftment potential in NOD/SCID/IL2Rγ-null-3/GM/SF mice and significantly prolonged survival. Our data suggest potential benefit of concomitant β-catenin and Bcr–Abl inhibition to prevent or overcome Bcr–Abl kinase-dependent or -independent TKI resistance in BC-CML. PMID:28321124

Combined inhibition of β-catenin and Bcr-Abl synergistically targets tyrosine kinase inhibitor-resistant blast crisis chronic myeloid leukemia blasts and progenitors in vitro and in vivo.

Science.gov (United States)

Zhou, H; Mak, P Y; Mu, H; Mak, D H; Zeng, Z; Cortes, J; Liu, Q; Andreeff, M; Carter, B Z

2017-10-01

Tyrosine kinase inhibitor (TKI) resistance and progression to blast crisis (BC), both related to persistent β-catenin activation, remain formidable challenges for chronic myeloid leukemia (CML). We observed overexpression of β-catenin in BC-CML stem/progenitor cells, particularly in granulocyte-macrophage progenitors, and highest among a novel CD34 + CD38 + CD123 hi Tim-3 hi subset as determined by CyTOF analysis. Co-culture with mesenchymal stromal cells (MSCs) induced the expression of β-catenin and its target CD44 in CML cells. A novel Wnt/β-catenin signaling modulator, C82, and nilotinib synergistically killed KBM5 T315I and TKI-resistant primary BC-CML cells with or without BCR-ABL kinase mutations even under leukemia/MSC co-culture conditions. Silencing of β-catenin by short interfering RNA restored sensitivity of primary BCR-ABL T315I/E255V BC-CML cells to nilotinib. Combining the C82 pro-drug, PRI-724, with nilotinib significantly prolonged the survival of NOD/SCID/IL2Rγ null mice injected with primary BCR-ABL T315I/E255V BC-CML cells. The combined treatment selectively targeted CML progenitors and inhibited CD44, c-Myc, survivin, p-CRKL and p-STAT5 expression. In addition, pretreating primary BC-CML cells with C82, or the combination, but not with nilotinib alone, significantly impaired their engraftment potential in NOD/SCID/IL2Rγ-null-3/GM/SF mice and significantly prolonged survival. Our data suggest potential benefit of concomitant β-catenin and Bcr-Abl inhibition to prevent or overcome Bcr-Abl kinase-dependent or -independent TKI resistance in BC-CML.

Characterization of differential gene expression in adrenocortical tumors harboring beta-catenin (CTNNB1) mutations.

Science.gov (United States)

Durand, Julien; Lampron, Antoine; Mazzuco, Tania L; Chapman, Audrey; Bourdeau, Isabelle

2011-07-01

Mutations of β-catenin gene (CTNNB1) are frequent in adrenocortical adenomas (AA) and adrenocortical carcinomas (ACC). However, the target genes of β-catenin have not yet been identified in adrenocortical tumors. Our objective was to identify genes deregulated in adrenocortical tumors harboring CTNNB1 genetic alterations and nuclear accumulation of β-catenin. Microarray analysis identified a dataset of genes that were differently expressed between AA with CTNNB1 mutations and wild-type (WT) tumors. Within this dataset, the expression profiles of five genes were validated by real time-PCR (RT-PCR) in a cohort of 34 adrenocortical tissues (six AA and one ACC with CTNNB1 mutations, 13 AA and four ACC with WT CTNNB1, and 10 normal adrenal glands) and two human ACC cell lines. We then studied the effects of suppressing β-catenin transcriptional activity with the T-cell factor/β-catenin inhibitors PKF115-584 and PNU74654 on gene expression in H295R and SW13 cells. RT-PCR analysis confirmed the overexpression of ISM1, RALBP1, and PDE2A and the down-regulation of PHYHIP in five of six AA harboring CTNNB1 mutations compared with WT AA (n = 13) and normal adrenal glands (n = 10). RALBP1 and PDE2A overexpression was also confirmed at the protein level by Western blotting analysis in mutated tumors. ENC1 was specifically overexpressed in three of three AA harboring CTNNB1 point mutations. mRNA expression and protein levels of RALBP1, PDE2A, and ENC1 were decreased in a dose-dependent manner in H295R cells after treatment with PKF115-584 or PNU74654. This study identified candidate genes deregulated in CTNNB1-mutated adrenocortical tumors that may lead to a better understanding of the role of the Wnt-β-catenin pathway in adrenocortical tumorigenesis.

Genetic disruption of tubulin acetyltransferase, αTAT1, inhibits proliferation and invasion of colon cancer cells through decreases in Wnt1/β-catenin signaling

International Nuclear Information System (INIS)

Oh, Somi; You, Eunae; Ko, Panseon; Jeong, Jangho; Keum, Seula; Rhee, Sangmyung

2017-01-01

Microtubules are required for diverse cellular processes, and abnormal regulation of microtubule dynamics is closely associated with severe diseases including malignant tumors. In this study, we report that α-tubulin N-acetyltransferase (αTAT1), a regulator of α-tubulin acetylation, is required for colon cancer proliferation and invasion via regulation of Wnt1 and its downstream genes expression. Public transcriptome analysis showed that expression of ATAT1 is specifically upregulated in colon cancer tissue. A knockout (KO) of ATAT1 in the HCT116 colon cancer cell line, using the CRISPR/Cas9 system showed profound inhibition of proliferative and invasive activities of these cancer cells. Overexpression of αTAT1 or the acetyl-mimic K40Q α-tubulin mutant in αTAT1 KO cells restored the invasiveness, indicating that microtubule acetylation induced by αTAT1 is critical for HCT116 cell invasion. Analysis of colon cancer-related gene expression in αTAT1 KO cells revealed that the loss of αTAT1 decreased the expression of WNT1. Mechanistically, abrogation of tubulin acetylation by αTAT1 knockout inhibited localization of β-catenin to the plasma membrane and nucleus, thereby resulting in the downregulation of Wnt1 and of its downstream genes including CCND1, MMP-2, and MMP-9. These results suggest that αTAT1-mediated Wnt1 expression via microtubule acetylation is important for colon cancer progression. - Highlights: • Ablation of αTAT1 inhibits HCT116 colon cancer cell invasion. • αTAT1/acetylated microtubules regulate expression of Wnt1/β-catenin target genes. • Acetylated microtubules regulate cellular localization of β-catenin. • Loss of αTAT1 prevents Wnt1 from inducing β-catenin-dependent and -independent pathways.

Inhibition of Breast Cancer Metastasis by Heregulin-Beta 1

National Research Council Canada - National Science Library

Yu, Dihua

1999-01-01

The major goal of this Idea proposal is to determine whether and how HRG-Beta1 inhibits breast cancer metastasis and to identify the functional domains that are sufficient for inhibition of breast cancer metastasis...

Wnt/β-catenin signaling regulates cancer stem cells in lung cancer A549 cells

International Nuclear Information System (INIS)

Teng, Ying; Wang, Xiuwen; Wang, Yawei; Ma, Daoxin

2010-01-01

Wnt/β-catenin signaling plays an important role not only in cancer, but also in cancer stem cells. In this study, we found that β-catenin and OCT-4 was highly expressed in cisplatin (DDP) selected A549 cells. Stimulating A549 cells with lithium chloride (LiCl) resulted in accumulation of β-catenin and up-regulation of a typical Wnt target gene cyclin D1. This stimulation also significantly enhanced proliferation, clone formation, migration and drug resistance abilities in A549 cells. Moreover, the up-regulation of OCT-4, a stem cell marker, was observed through real-time PCR and Western blotting. In a reverse approach, we inhibited Wnt signaling by knocking down the expression of β-catenin using RNA interference technology. This inhibition resulted in down-regulation of the Wnt target gene cyclin D1 as well as the proliferation, clone formation, migration and drug resistance abilities. Meanwhile, the expression of OCT-4 was reduced after the inhibition of Wnt/β-catenin signaling. Taken together, our study provides strong evidence that canonical Wnt signaling plays an important role in lung cancer stem cell properties, and it also regulates OCT-4, a lung cancer stem cell marker.

Long noncoding RNA AK126698 inhibits proliferation and migration of non-small cell lung cancer cells by targeting Frizzled-8 and suppressing Wnt/β-catenin signaling pathway

Directory of Open Access Journals (Sweden)

Fu X

2016-06-01

Full Text Available Xiao Fu,1 Hui Li,1 Chunxiao Liu,2 Bin Hu,1 Tong Li,1 Yang Wang1 1Department of Thoracic Surgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 2Department of Cardiovascular Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, People’s Republic of China Background: Recent studies indicate that long noncoding RNAs (lncRNAs play a key role in the control of cellular processes such as proliferation, metastasis, and differentiation. The lncRNA dysregulation has been identified in all types of cancer. We previously found that lncRNA AK126698 suppresses cisplatin resistance in A549 cells through the Wnt/β-catenin signaling pathway. However, the clinical significance of lncRNA AK126698 and the molecular mechanisms through which it regulates cancer cell proliferation and migration are largely unknown. Methods: We examined the expression of lncRNA AK126698 in 56 non-small cell lung cancer (NSCLC tissue samples and three NSCLC cell lines using quantitative real-time polymerase chain reaction. Gain and loss of function approaches were used to evaluate the biological function of AK126698 in NSCLC cells. The effects of lncRNA AK126698 on cell proliferation were investigated using cell counting kit-8 and 5-ethynyl-2'-deoxyuridine assays, and apoptosis was measured by flow cytometry. Protein levels of AK126698 targets were evaluated by Western blotting. Results: Our results showed that lncRNA AK126698 was significantly downregulated in NSCLC tissues, compared with paired adjacent nontumor tissue samples. Furthermore, lower AK126698 expression was associated with larger tumor size and advanced tumor stage. Ectopic AK126698 expression inhibited cell proliferation and migration and induced apoptosis. Conversely, decreased AK126698 expression promoted cell proliferation and migration and inhibited cell apoptosis. Importantly, we demonstrated that Frizzled-8, a receptor of Wnt/β-catenin pathway, was a target of AK126698. Furthermore

Inhibition of human melanoma cell growth by dietary flavonoid fisetin is associated with disruption of Wnt/β-catenin signaling and decreased Mitf levels

Science.gov (United States)

Syed, Deeba N.; Afaq, Farrukh; Maddodi, Nityanand; Johnson, Jeremy J.; Sarfaraz, Sami; Ahmad, Adeel; Setaluri, Vijayasaradhi; Mukhtar, Hasan

2011-01-01

The prognosis of advanced melanoma remains poor in spite of treatment advances, emphasizing the importance of additional preventive measures. Flavonoids, natural components of our diet are being investigated for their chemopreventive/therapeutic properties. Microphthalmia-associated transcription factor (Mitf), downstream of Wnt/β-catenin pathway has become an important prognostic marker of melanoma. Here, we show that treatment of 451Lu melanoma cells with the dietary flavonoid fisetin resulted in decreased cell viability with G1-phase arrest and disruption of Wnt/β-catenin signaling. This was accompanied with a decrease in expression of Wnt protein and its co-receptors and a parallel increase in the expression of endogenous Wnt inhibitors. Fisetin-treated cells showed increased cytosolic levels of Axin and β-TrCP and decreased phosphorylation of GSK3-β assocaited with decreased β-catenin stabilization. Fisetin-mediated interference with the functional cooperation between β-catenin and LEF/TCF-2 resulted in downregulation of positively regulated TCF targets such as c-myc, Brn-2 and Mitf. Flowcytometric analysis of Mitf overexpressing cells showed that fisetin repressed Mitf-induced cell proliferation. Finally, administration of fisetin to 451Lu xenografted nude mice resulted in inhibition of tumor development and decreased Mitf expression. Our data suggest that fisetin can be developed as an effective agent against melanoma due to its potential inhibitory effect on β-catenin/Mitf signaling. PMID:21346776

Selective inhibition of sheep kidney 11 beta-hydroxysteroid dehydrogenase isoform 2 activity by 5 alpha-reduced (but not 5 beta) derivatives of adrenocorticosteroids.

Science.gov (United States)

Latif, S A; Sheff, M F; Ribeiro, C E; Morris, D J

1997-02-01

We have previously reported that 5 alpha and 5 beta pathways of steroid metabolism are controlled in vivo by dietary Na+ and glycyrrhetinic acid, see Gorsline et al. 1988; Latif et al. 1990. The present investigations provide evidence supporting the suggestion that endogenous substances may regulate the glucocorticoid inactivating isoenzymes, 11 beta-HSD (hydroxysteroid dehydrogenase) 1 (liver) and 11 beta-HSD2 (kidney). The activity of 11 beta-HSD is impaired in essential hypertension, following licorice ingestion, and in patients with apparent mineralocorticoid excess where 11 beta-HSD2 is particularly affected. In all three conditions, excretion of the less common 5 alpha metabolites is elevated in urine. We now report on the differential abilities of a series of Ring A reduced (5 alpha and 5 beta) adrenocorticosteroid and progesterone metabolites to inhibit these isoenzymes. Using liver microsomes with NADP+ as co-factor (11 beta-HSD1), and sheep kidney microsomes with NAD+ as co-factor (11 beta-HSD2), we have systematically investigated the abilities of a number of adrenocorticosteroids and their derivatives to inhibit the individual isoforms of 11 beta-HSD. A striking feature is the differential sensitivity of the two isoenzymes to inhibition by 5 alpha and 5 beta derivatives. 11 beta-HSD1 is inhibited by both 5 alpha and certain 5 beta derivatives. 11 beta-HSD-2 was selectively inhibited only by 5 alpha derivatives: 5 beta derivatives were without inhibitory activity toward this isoform of 11 beta-HSD. These results indicate the importance of the structural conformation of the A and B Rings in conferring specific inhibitory properties on these compounds. In addition, we discuss the effects of additions or substitutions of other functional groups on the inhibitory potency of these steroid molecules against 11 beta-HSD1 and 11 beta-HSD2.

Lead induces chondrogenesis and alters transforming growth factor-beta and bone morphogenetic protein signaling in mesenchymal cell populations.

Science.gov (United States)

Zuscik, Michael J; Ma, Lin; Buckley, Taylor; Puzas, J Edward; Drissi, Hicham; Schwarz, Edward M; O'Keefe, Regis J

2007-09-01

It has been established that skeletal growth is stunted in lead-exposed children. Because chondrogenesis is a seminal step during skeletal development, elucidating the impact of Pb on this process is the first step toward understanding the mechanism of Pb toxicity in the skeleton. The aim of this study was to test the hypothesis that Pb alters chondrogenic commitment of mesenchymal cells and to assess the effects of Pb on various signaling pathways. We assessed the influence of Pb on chondrogenesis in murine limb bud mesenchymal cells (MSCs) using nodule formation assays and gene analyses. The effects of Pb on transforming growth factor-beta (TGF-beta) and bone morphogenetic protein (BMP) signaling was studied using luciferase-based reporters and Western analyses, and luciferase-based assays were used to study cyclic adenosine monophosphate response element binding protein (CREB), beta-catenin, AP-1, and nuclear factor-kappa B (NF-kappaB) signaling. We also used an ectopic bone formation assay to determine how Pb affects chondrogenesis in vivo. Pb-exposed MSCs showed enhanced basal and TGF-beta/BMP induction of chondrogenesis, evidenced by enhanced nodule formation and up-regulation of Sox-9, type 2 collagen, and aggrecan, all key markers of chondrogenesis. We observed enhanced chondrogenesis during ectopic bone formation in mice preexposed to Pb via drinking water. In MSCs, Pb enhanced TGF-beta but inhibited BMP-2 signaling, as measured by luciferase reporter assays and Western analyses of Smad phosphorylation. Although Pb had no effect on basal CREB or Wnt/beta-catenin pathway activity, it induced NFkappaB signaling and inhibited AP-1 signaling. The in vitro and in vivo induction of chondrogenesis by Pb likely involves modulation and integration of multiple signaling pathways including TGF-beta, BMP, AP-1, and NFkappaB.

Inhibition of Cyclic Adenosine Monophosphate (cAMP-response Element-binding Protein (CREB-binding Protein (CBP/β-Catenin Reduces Liver Fibrosis in Mice

Directory of Open Access Journals (Sweden)

Yosuke Osawa

2015-11-01

Full Text Available Wnt/β-catenin is involved in every aspect of embryonic development and in the pathogenesis of many human diseases, and is also implicated in organ fibrosis. However, the role of β-catenin-mediated signaling on liver fibrosis remains unclear. To explore this issue, the effects of PRI-724, a selective inhibitor of the cAMP-response element-binding protein-binding protein (CBP/β-catenin interaction, on liver fibrosis were examined using carbon tetrachloride (CCl4- or bile duct ligation (BDL-induced mouse liver fibrosis models. Following repetitive CCl4 administrations, the nuclear translocation of β-catenin was observed only in the non-parenchymal cells in the liver. PRI-724 treatment reduced the fibrosis induced by CCl4 or BDL. C-82, an active form of PRI-724, inhibited the activation of isolated primary mouse quiescent hepatic stellate cells (HSCs and promoted cell death in culture-activated HSCs. During the fibrosis resolution period, an increase in F4/80+ CD11b+ and Ly6Clow CD11b+ macrophages was induced by CCl4 and was sustained for two weeks thereafter, even after having stopped CCl4 treatment. PRI-724 accelerated the resolution of CCl4-induced liver fibrosis, and this was accompanied by increased matrix metalloproteinase (MMP-9, MMP-2, and MMP-8 expression in intrahepatic leukocytes. In conclusion, targeting the CBP/β-catenin interaction may become a new therapeutic strategy in treating liver fibrosis.

Natural derivatives of curcumin attenuate the Wnt/β-catenin pathway through down-regulation of the transcriptional coactivator p300

International Nuclear Information System (INIS)

Ryu, Min-Jung; Cho, Munju; Song, Jie-Young; Yun, Yeon-Sook; Choi, Il-Whan; Kim, Dong-Eun; Park, Byeoung-Soo; Oh, Sangtaek

2008-01-01

Curcumin, a component of turmeric (Curcuma longa), has been reported to suppress β-catenin response transcription (CRT), which is aberrantly activated in colorectal cancer. However, the effects of its natural analogs (demethoxycurcumin [DMC] and bisdemethoxycurcumin [BDMC]) and metabolite (tetrahydrocurcumin [THC]) on the Wnt/β-catenin pathway have not been investigated. Here, we show that DMC and BDMC suppressed CRT that was activated by Wnt3a conditioned-medium (Wnt3a-CM) without altering the level of intracellular β-catenin, and inhibited the growth of various colon cancer cells, with comparable potency to curcumin. Additionally, DMC and BDMC down-regulated p300, which is a positive regulator of the Wnt/β-catenin pathway. Notably, THC also inhibited CRT and cell proliferation, but to a much lesser degree than curcumin, DMC, or BDMC, indicating that the conjugated bonds in the central seven-carbon chain of curcuminoids are essential for the inhibition of Wnt/β-catenin pathway and the anti-proliferative activity of curcuminoids. Thus, our findings suggest that curcumin derivatives inhibit the Wnt/β-catenin pathway by decreasing the amount of the transcriptional coactivator p300.

Ovatodiolide Targets β-Catenin Signaling in Suppressing Tumorigenesis and Overcoming Drug Resistance in Renal Cell Carcinoma

Directory of Open Access Journals (Sweden)

Jar-Yi Ho

2013-01-01

Full Text Available Dysregulated β-catenin signaling is intricately involved in renal cell carcinoma (RCC carcinogenesis and progression. Determining potential β-catenin signaling inhibitors would be helpful in ameliorating drug resistance in advanced or metastatic RCC. Screening for β-catenin signaling inhibitors involved in silico inquiry of the PubChem Bioactivity database followed by TCF/LEF reporter assay. The biological effects of ovatodiolide were evaluated in 4 RCC cell lines in vitro and 2 RCC cell lines in a mouse xenograft model. The synergistic effects of ovatodiolide and sorafenib or sunitinib were examined in 2 TKI-resistant RCC cell lines. Ovatodiolide, a pure compound of Anisomeles indica, inhibited β-catenin signaling and reduced RCC cell viability, survival, migration/invasion, and in vitro cell or in vivo mouse tumorigenicity. Cytotoxicity was significantly reduced in a normal kidney epithelial cell line with the treatment. Ovatodiolide reduced phosphorylated β-catenin (S552 that inhibited β-catenin nuclear translocation. Moreover, ovatodiolide decreased β-catenin stability and impaired the association of β-catenin and transcription factor 4. Ovatodiolide combined with sorafenib or sunitinib overcame drug resistance in TKI-resistant RCC cells. Ovatodiolide may be a potent β-catenin signaling inhibitor, with synergistic effects with sorafenib or sunitinib, and therefore, a useful candidate for improving RCC therapy.

Human cytomegalovirus infection dysregulates the canonical Wnt/β-catenin signaling pathway.

Directory of Open Access Journals (Sweden)

Magdalena Angelova

Full Text Available Human Cytomegalovirus (HCMV is a ubiquitous herpesvirus that currently infects a large percentage of the world population. Although usually asymptomatic in healthy individuals, HCMV infection during pregnancy may cause spontaneous abortions, premature delivery, or permanent neurological disabilities in infants infected in utero. During infection, the virus exerts control over a multitude of host signaling pathways. Wnt/β-catenin signaling, an essential pathway involved in cell cycle control, differentiation, embryonic development, placentation and metastasis, is frequently dysregulated by viruses. How HCMV infection affects this critical pathway is not currently known. In this study, we demonstrate that HCMV dysregulates Wnt/β-catenin signaling in dermal fibroblasts and human placental extravillous trophoblasts. Infection inhibits Wnt-induced transcriptional activity of β-catenin and expression of β-catenin target genes in these cells. HCMV infection leads to β-catenin protein accumulation in a discrete juxtanuclear region. Levels of β-catenin in membrane-associated and cytosolic pools, as well as nuclear β-catenin, are reduced after infection; while transcription of the β-catenin gene is unchanged, suggesting enhanced degradation. Given the critical role of Wnt/β-catenin signaling in cellular processes, these findings represent a novel and important mechanism whereby HCMV disrupts normal cellular function.

Structure-activity studies of Wnt/β-catenin inhibition in the Niclosamide chemotype: Identification of derivatives with improved drug exposure.

Science.gov (United States)

Mook, Robert A; Wang, Jiangbo; Ren, Xiu-Rong; Chen, Minyong; Spasojevic, Ivan; Barak, Larry S; Lyerly, H Kim; Chen, Wei

2015-09-01

The Wnt signaling pathway plays a key role in regulation of organ development and tissue homeostasis. Dysregulated Wnt activity is one of the major underlying mechanisms responsible for many diseases including cancer. We previously reported the FDA-approved anthelmintic drug Niclosamide inhibits Wnt/β-catenin signaling and suppresses colon cancer cell growth in vitro and in vivo. Niclosamide is a multi-functional drug that possesses important biological activity in addition to inhibition of Wnt/β-catenin signaling. Here, we studied the SAR of Wnt signaling inhibition in the anilide and salicylamide region of Niclosamide. We found that the 4'-nitro substituent can be effectively replaced by trifluoromethyl or chlorine and that the potency of inhibition was dependent on the substitution pattern in the anilide ring. Non-anilide, N-methyl amides and reverse amide derivatives lost significant potency, while acylated salicylamide derivatives inhibited signaling with potency similar to non-acyl derivatives. Niclosamide's low systemic exposure when dosed orally may hinder its use to treat systemic disease. To overcome this limitation we identified an acyl derivative of Niclosamide, DK-520 (compound 32), that significantly increased both the plasma concentration and the duration of exposure of Niclosamide when dosed orally. The studies herein provide a medicinal chemical foundation to improve the pharmacokinetic exposure of Niclosamide and Wnt-signaling inhibitors based on the Niclosamide chemotype. The identification of novel derivatives of Niclosamide that metabolize to Niclosamide and increase its drug exposure may provide important research tools for in vivo studies and provide drug candidates for treating cancers with dysregulated Wnt signaling including drug-resistant cancers. Moreover, since Niclosamide is a multi-functional drug, new research tools such as DK520 could directly result in novel treatments against bacterial and viral infection, lupus, and metabolic

Structure–activity studies of Wnt/β-catenin inhibition in the Niclosamide chemotype: Identification of derivatives with improved drug exposure

Science.gov (United States)

Mook, Robert A.; Wang, Jiangbo; Ren, Xiu-Rong; Chen, Minyong; Spasojevic, Ivan; Barak, Larry S.; Lyerly, H. Kim; Chen, Wei

2015-01-01

The Wnt signaling pathway plays a key role in regulation of organ development and tissue homeostasis. Dysregulated Wnt activity is one of the major underlying mechanisms responsible for many diseases including cancer. We previously reported the FDA-approved anthelmintic drug Niclosamide inhibits Wnt/β-catenin signaling and suppresses colon cancer cell growth in vitro and in vivo. Niclosamide is a multi-functional drug that possesses important biological activity in addition to inhibition of Wnt/β-catenin signaling. Here, we studied the SAR of Wnt signaling inhibition in the anilide and salicylamide region of Niclosamide. We found that the 4′-nitro substituent can be effectively replaced by trifluoromethyl or chlorine and that the potency of inhibition was dependent on the substitution pattern in the anilide ring. Non-anilide, N-methyl amides and reverse amide derivatives lost significant potency, while acylated salicylamide derivatives inhibited signaling with potency similar to non-acyl derivatives. Niclosamide's low systemic exposure when dosed orally may hinder its use to treat systemic disease. To overcome this limitation we identified an acyl derivative of Niclosamide, DK-520 (compound 32), that significantly increased both the plasma concentration and the duration of exposure of Niclosamide when dosed orally. The studies herein provide a medicinal chemical foundation to improve the pharmacokinetic exposure of Niclosamide and Wnt-signaling inhibitors based on the Niclosamide chemotype. The identification of novel derivatives of Niclosamide that metabolize to Niclosamide and increase its drug exposure may provide important research tools for in vivo studies and provide drug candidates for treating cancers with dysregulated Wnt signaling including drug-resistant cancers. Moreover, since Niclosamide is a multifunctional drug, new research tools such as DK520 could directly result in novel treatments against bacterial and viral infection, lupus, and metabolic

Modulation of β-catenin signaling by glucagon receptor activation.

Directory of Open Access Journals (Sweden)

Jiyuan Ke

Full Text Available The glucagon receptor (GCGR is a member of the class B G protein-coupled receptor family. Activation of GCGR by glucagon leads to increased glucose production by the liver. Thus, glucagon is a key component of glucose homeostasis by counteracting the effect of insulin. In this report, we found that in addition to activation of the classic cAMP/protein kinase A (PKA pathway, activation of GCGR also induced β-catenin stabilization and activated β-catenin-mediated transcription. Activation of β-catenin signaling was PKA-dependent, consistent with previous reports on the parathyroid hormone receptor type 1 (PTH1R and glucagon-like peptide 1 (GLP-1R receptors. Since low-density-lipoprotein receptor-related protein 5 (Lrp5 is an essential co-receptor required for Wnt protein mediated β-catenin signaling, we examined the role of Lrp5 in glucagon-induced β-catenin signaling. Cotransfection with Lrp5 enhanced the glucagon-induced β-catenin stabilization and TCF promoter-mediated transcription. Inhibiting Lrp5/6 function using Dickkopf-1(DKK1 or by expression of the Lrp5 extracellular domain blocked glucagon-induced β-catenin signaling. Furthermore, we showed that Lrp5 physically interacted with GCGR by immunoprecipitation and bioluminescence resonance energy transfer assays. Together, these results reveal an unexpected crosstalk between glucagon and β-catenin signaling, and may help to explain the metabolic phenotypes of Lrp5/6 mutations.

β-catenin expression in minipigs transgenic for human mutated huntingtin

Czech Academy of Sciences Publication Activity Database

Žižková, Martina; Hrabáková, Rita; Juhásová, Jana; Juhás, Štefan; Halada, Petr; Kovářová, Hana; Motlík, Jan

2012-01-01

Roč. 83, Suppl 1 (2012), A15-A16 ISSN 0022-3050. [EHDN Plenary Meeting /7./. 14.02.2012-16.02.2012, Stockholm] R&D Projects: GA TA ČR TA01011466 Institutional support: RVO:67985904 ; RVO:61388971 Keywords : beta-catenin * Huntington disease Subject RIV: CE - Biochemistry

Inhibition of Alzheimer amyloid {beta} aggregation by polyvalent trehalose

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Miura, Yoshiko; You, Chouga [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Ohnishi, Reiko [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)], E-mail: miuray@jaist.ac.jp

2008-04-15

A glycopolymer carrying trehalose was found to suppress the formation of amyloid fibrils from the amyloid {beta} peptide (1-42) (A{beta}), as evaluated by thioflavin T assay and atomic force microscopy. Glycopolymers carrying sugar alcohols also changed the aggregation properties of A{beta}, and the inhibitory effect depended on the type of sugar and alkyl side chain. Neutralization activity was confirmed by in vitro assay using HeLa cells. The glycopolymer carrying trehalose strongly inhibited amyloid formation and neutralized cytotoxicity.

Galectin-3 silencing inhibits epirubicin-induced ATP binding cassette transporters and activates the mitochondrial apoptosis pathway via β-catenin/GSK-3β modulation in colorectal carcinoma.

Directory of Open Access Journals (Sweden)

Yung-Kuo Lee

Full Text Available Multidrug resistance (MDR, an unfavorable factor compromising the treatment efficacy of anticancer drugs, involves the upregulation of ATP binding cassette (ABC transporters and induction of galectin-3 signaling. Galectin-3 plays an anti-apoptotic role in many cancer cells and regulates various pathways to activate MDR. Thus, the inhibition of galectin-3 has the potential to enhance the efficacy of the anticancer drug epirubicin. In this study, we examined the effects and mechanisms of silencing galectin-3 via RNA interference (RNAi on the β-catenin/GSK-3β pathway in human colon adenocarcinoma Caco-2 cells. Galectin-3 knockdown increased the intracellular accumulation of epirubicin in Caco-2 cells; suppressed the mRNA expression of galectin-3, β-catenin, cyclin D1, c-myc, P-glycoprotein (P-gp, MDR-associated protein (MRP 1, and MRP2; and downregulated the protein expression of P-gp, cyclin D1, galectin-3, β-catenin, c-Myc, and Bcl-2. Moreover, galectin-3 RNAi treatment significantly increased the mRNA level of GSK-3β, Bax, caspase-3, and caspase-9; remarkably increased the Bax-to-Bcl-2 ratio; and upregulated the GSK-3β and Bax protein expressions. Apoptosis was induced by galectin-3 RNAi and/or epirubicin as demonstrated by chromatin condensation, a higher sub-G1 phase proportion, and increased caspase-3 and caspase-9 activity, indicating an intrinsic/mitochondrial apoptosis pathway. Epirubicin-mediated resistance was effectively inhibited via galectin-3 RNAi treatment. However, these phenomena could be rescued after galectin-3 overexpression. We show for the first time that the silencing of galectin-3 sensitizes MDR cells to epirubicin by inhibiting ABC transporters and activating the mitochondrial pathway of apoptosis through modulation of the β-catenin/GSK-3β pathway in human colon cancer cells.

Mesenchymal Wnt/β-catenin signaling limits tooth number.

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Järvinen, Elina; Shimomura-Kuroki, Junko; Balic, Anamaria; Jussila, Maria; Thesleff, Irma

2018-02-21

Tooth agenesis is one of the predominant developmental anomalies in humans, usually affecting the permanent dentition generated by sequential tooth formation and, in most cases, caused by mutations perturbing epithelial Wnt/β-catenin signaling. In addition, loss-of-function mutations in the Wnt feedback inhibitor AXIN2 lead to human tooth agenesis. We have investigated the functions of Wnt/β-catenin signaling during sequential formation of molar teeth using mouse models. Continuous initiation of new teeth, which is observed after genetic activation of Wnt/β-catenin signaling in the oral epithelium, was accompanied by enhanced expression of Wnt antagonists and a downregulation of Wnt/β-catenin signaling in the dental mesenchyme. Genetic and pharmacological activation of mesenchymal Wnt/β-catenin signaling negatively regulated sequential tooth formation, an effect partly mediated by Bmp4. Runx2 , a gene whose loss-of-function mutations result in sequential formation of supernumerary teeth in the human cleidocranial dysplasia syndrome, suppressed the expression of Wnt inhibitors Axin2 and Drapc1 in dental mesenchyme. Our data indicate that increased mesenchymal Wnt signaling inhibits the sequential formation of teeth, and suggest that Axin2 / Runx2 antagonistic interactions modulate the level of mesenchymal Wnt/β-catenin signaling, underlying the contrasting dental phenotypes caused by human AXIN2 and RUNX2 mutations. © 2018. Published by The Company of Biologists Ltd.

MiR-129-5p Inhibits Proliferation and Invasion of Chondrosarcoma Cells by Regulating SOX4/Wnt/β-Catenin Signaling Pathway.

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Zhang, Peng; Li, Jifeng; Song, Yuze; Wang, Xiao

2017-01-01

Recently, microRNAs (miRNA) have been identified as novel regulators in Chondrosarcoma (CHS). This study was aimed to identify the roles of miR-129-5p-5p in regulation of SOX4 and Wnt/β-catenin signaling pathway, as well as cell proliferation and apoptosis in chondrosarcomas. Tissue samples were obtained from chondrosarcoma patients. Immunohistochemistry, real-time quantitative RT-PCR (RT-qPCR) and western blot analysis were performed to detect the expressions of miR-129-5p and SOX4. Luciferase assay was conducted to confirm that miR-129-5p directly targeted SOX4 mRNA. Manipulations of miR-129-5p and SOX4 expression were achieved through cell transfection. Cell proliferation, migration and apoptosis were evaluated by CCK-8 assay, colony forming assay, wound healing assay and flow cytometry in vitro. For in vivo experiment, the tumor xenograft model was established to evaluate the effects of miR-129-5p and SOX4 on chondrosarcomas. The expression of miR-129-5p was significantly down-regulated in chondrosarcoma tissues as well as cells in comparison with normal ones, while SOX4 was over-activated. Further studies suggested that miR-129-5p suppressed cell proliferation, migration and promoted apoptosis by inhibiting SOX4 and Wnt/β-catenin pathway. MiR-129-5p inhibits the Wnt/β-catenin signaling pathway by targeting SOX4 and further suppresses cell proliferation, migration and promotes apoptosis in chondrosarcomas. © 2017 The Author(s). Published by S. Karger AG, Basel.

Wnt/β-catenin pathway involvement in ionizing radiation-induced invasion of U87 glioblastoma cells

International Nuclear Information System (INIS)

Dong, Zhen; Zhou, Lin; Han, Na; Zhang, Mengxian; Lyu, Xiaojuan

2015-01-01

Radiotherapy has been reported to promote the invasion of glioblastoma cells; however, the underlying mechanisms remain unclear. Here, we investigated the role of the Wnt/β-catenin pathway in radiation-induced invasion of glioblastoma cells. U87 cells were irradiated with 3 Gy or sham irradiated in the presence or absence of the Wnt/β-catenin pathway inhibitor XAV 939. Cell invasion was determined by an xCELLigence real-time cell analyser and matrigel invasion assays. The intracellular distribution of β-catenin in U87 cells with or without irradiation was examined by immunofluorescence and Western blotting of nuclear fractions. We next investigated the effect of irradiation on Wnt/β-catenin pathway activity using TOP/FOP flash luciferase assays and quantitative polymerase chain reaction analysis of β-catenin target genes. The expression levels and activities of two target genes, matrix metalloproteinase (MMP)-2 and MMP-9, were examined further by Western blotting and zymography. U87 cell invasiveness was increased significantly by ionizing radiation. Interestingly, ionizing radiation induced nuclear translocation and accumulation of β-catenin. Moreover, we found increased β-catenin/TCF transcriptional activities, followed by up-regulation of downstream genes in the Wnt/β-catenin pathway in irradiated U87 cells. Importantly, inhibition of the Wnt/β-catenin pathway by XAV 939, which promotes degradation of β-catenin, significantly abrogated the pro-invasion effects of irradiation. Mechanistically, XAV 939 suppressed ionizing radiation-triggered up-regulation of MMP-2 and MMP-9, and inhibited the activities of these gelatinases. Our data demonstrate a pivotal role of the Wnt/β-catenin pathway in ionizing radiation-induced invasion of glioblastoma cells, and suggest that targeting β-catenin is a promising therapeutic approach to overcoming glioma radioresistance. (orig.) [de

Inhibition of Wnt/β-catenin signaling by IWR1 induces expression of Foxd3 to promote mouse epiblast stem cell self-renewal.

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Liu, Kuisheng; Sun, Yuanyuan; Liu, Dahai; Ye, Shoudong

2017-08-26

Inhibition of Wnt/β-catenin signaling facilitates the derivation of mouse epiblast stem cells (EpiSCs), as well as dramatically promotes EpiSC self-renewal. The specific mechanism, however, is still unclear. Here, we showed that IWR1, a Wnt/β-catenin signaling inhibitor, allowed long-term self-renewal of EpiSCs in serum medium in combination with ROCK inhibitor Y27632. Through transcriptome data analysis, we arrived at a set of candidate transcription factors induced by IWR1. Among these, Forkhead box D3 (Foxd3) was most abundant. Forced expression of Foxd3 could recapitulate the self-renewal-promoting effect of IWR1 in EpiSCs. Conversely, knockdown of Foxd3 profoundly compromised responsiveness to IWR1, causing extinction of pluripotency markers and emergence of differentiation phenotype. Foxd3 thus is necessary and sufficient to mediate self-renewal downstream of Wnt/β-catenin signaling inhibitor. These findings highlight an important role for Foxd3 in regulating EpiSCs and will expand current understanding of the primed pluripotency. Copyright © 2017 Elsevier Inc. All rights reserved.

The low-density lipoprotein receptor-related protein 10 is a negative regulator of the canonical Wnt/β-catenin signaling pathway

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Jeong, Young-Hee; Sekiya, Manami; Hirata, Michiko; Ye, Mingjuan; Yamagishi, Azumi; Lee, Sang-Mi; Kang, Man-Jong; Hosoda, Akemi; Fukumura, Tomoe; Kim, Dong-Ho; Saeki, Shigeru

2010-01-01

Wnt signaling pathways play fundamental roles in the differentiation, proliferation and functions of many cells as well as developmental, growth, and homeostatic processes in animals. Low-density lipoprotein receptor (LDLR)-related protein (LRP) 5 and LRP6 serve as coreceptors of Wnt proteins together with Frizzled receptors, triggering activation of canonical Wnt/β-catenin signaling. Here, we found that LRP10, a new member of the LDLR gene family, inhibits the canonical Wnt/β-catenin signaling pathway. The β-catenin/T cell factor (TCF) transcriptional activity in HEK293 cells was activated by transfection with Wnt3a or LRP6, which was then inhibited by co-transfection with LRP10. Deletion of the extracellular domain of LRP10 negated its inhibitory effect. The inhibitory effect of LRP10 was consistently conserved in HEK293 cells even when GSK3β phosphorylation was inhibited by incubation with lithium chloride and co-transfection with constitutively active S33Y-mutated β-catenin. Nuclear β-catenin accumulation was unaffected by LRP10. The present studies suggest that LRP10 may interfere with the formation of the β-catenin/TCF complex and/or its binding to target DNA in the nucleus, and that the extracellular domain of LRP10 is critical for inhibition of the canonical Wnt/β-catenin signaling pathway.

Antibiotic drug rifabutin is effective against lung cancer cells by targeting the eIF4E-β-catenin axis

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Li, Ji; Huang, Yijiang [Department of Respiratory Medicine, Hainan General Hospital, Hainan Province (China); Gao, Yunsuo [Equipment Division, Hainan General Hospital, Hainan Province (China); Wu, Haihong; Dong, Wen [Department of Respiratory Medicine, Hainan General Hospital, Hainan Province (China); Liu, Lina, E-mail: echoliun@hotmail.com [Department of Ophthalmology, Hainan Eye Hospital, ZhongShan Ophthalmic Centre, Sun Yat-Sen University, Hainan Province (China)

2016-04-01

The essential roles of overexpression of eukaryotic translation initiation factor 4E (eIF4E) and aberrant activation of β-catenin in lung cancer development have been recently identified. However, whether there is a direct connection between eIF4E overexpression and β-catenin activation in lung cancer cells is unknown. In this study, we show that antibiotic drug rifabutin targets human lung cancer cells via inhibition of eIF4E-β-catenin axis. Rifabutin is effectively against lung cancer cells in in vitro cultured cells and in vivo xenograft mouse model through inhibiting proliferation and inducing apoptosis. Mechanistically, eIF4E regulates β-catenin activity in lung cancer cells as shown by the increased β-catenin phosphorylation and activity in cells overexpressing eIF4E, and furthermore that the regulation is dependent on phosphorylation at S209. Rifabutin suppresses eIF4E phosphorylation, leads to decreased β-catenin phosphorylation and its subsequent transcriptional activities. Depletion of eIF4E abolishes the inhibitory effects of rifabutin on β-catenin activities and overexpression of β-catenin reverses the inhibitory effects of rifabutin on cell growth and survival, further confirming that rifabutin acts on lung cancer cells via targeting eIF4E- β-catenin axis. Our findings identify the eIF4E- β-catenin axis as a critical regulator of lung cancer cell growth and survival, and suggest that its pharmacological inhibition may be therapeutically useful in lung cancer. - Highlights: • Rifabutin targets EGFR-mutated lung cancer cells in vitro and in vivo. • eIF4E phosphorylation regulates β-catenin activity in lung cancer cells. • Rifabutin acts on lung cancer cells via eIF4E- β-catenin axis. • Rifabutin can be repurposed for lung cancer treatment.

Antibiotic drug rifabutin is effective against lung cancer cells by targeting the eIF4E-β-catenin axis

International Nuclear Information System (INIS)

Li, Ji; Huang, Yijiang; Gao, Yunsuo; Wu, Haihong; Dong, Wen; Liu, Lina

2016-01-01

The essential roles of overexpression of eukaryotic translation initiation factor 4E (eIF4E) and aberrant activation of β-catenin in lung cancer development have been recently identified. However, whether there is a direct connection between eIF4E overexpression and β-catenin activation in lung cancer cells is unknown. In this study, we show that antibiotic drug rifabutin targets human lung cancer cells via inhibition of eIF4E-β-catenin axis. Rifabutin is effectively against lung cancer cells in in vitro cultured cells and in vivo xenograft mouse model through inhibiting proliferation and inducing apoptosis. Mechanistically, eIF4E regulates β-catenin activity in lung cancer cells as shown by the increased β-catenin phosphorylation and activity in cells overexpressing eIF4E, and furthermore that the regulation is dependent on phosphorylation at S209. Rifabutin suppresses eIF4E phosphorylation, leads to decreased β-catenin phosphorylation and its subsequent transcriptional activities. Depletion of eIF4E abolishes the inhibitory effects of rifabutin on β-catenin activities and overexpression of β-catenin reverses the inhibitory effects of rifabutin on cell growth and survival, further confirming that rifabutin acts on lung cancer cells via targeting eIF4E- β-catenin axis. Our findings identify the eIF4E- β-catenin axis as a critical regulator of lung cancer cell growth and survival, and suggest that its pharmacological inhibition may be therapeutically useful in lung cancer. - Highlights: • Rifabutin targets EGFR-mutated lung cancer cells in vitro and in vivo. • eIF4E phosphorylation regulates β-catenin activity in lung cancer cells. • Rifabutin acts on lung cancer cells via eIF4E- β-catenin axis. • Rifabutin can be repurposed for lung cancer treatment.

Glucose Deprivation Triggers Protein Kinase C-dependent β-Catenin Proteasomal Degradation*

Science.gov (United States)

Choi, Seung-Won; Song, Jun-Kyu; Yim, Ye-Seal; Yun, Ho-Geun; Chun, Kyung-Hee

2015-01-01

Autophagy is a conserved process that contributes to cell homeostasis. It is well known that induction mainly occurs in response to nutrient starvation, such as starvation of amino acids and insulin, and its mechanisms have been extensively characterized. However, the mechanisms behind cellular glucose deprivation-induced autophagy are as of now poorly understood. In the present study, we determined a mechanism by which glucose deprivation induced the PKC-dependent proteasomal degradation of β-catenin, leading to autophagy. Glucose deprivation was shown to cause a sub-G1 transition and enhancement of the LC3-II protein levels, whereas β-catenin protein underwent degradation in a proteasome-dependent manner. Moreover, the inhibition of GSK3β was unable to abolish the glucose deprivation-mediated β-catenin degradation or up-regulation of LC3-II protein levels, which suggested GSK3β-independent protein degradation. Intriguingly, the inhibition of PKCα using a pharmacological inhibitor and transfection of siRNA for PKCα was observed to effectively block glucose deprivation-induced β-catenin degradation as well as the increase in LC3-II levels and the accumulation of a sub-G1 population. Together, our results demonstrated a molecular mechanism by which glucose deprivation can induce the GSK3β-independent protein degradation of β-catenin, leading to autophagy. PMID:25691573

FANCL ubiquitinates β-catenin and enhances its nuclear function.

Science.gov (United States)

Dao, Kim-Hien T; Rotelli, Michael D; Petersen, Curtis L; Kaech, Stefanie; Nelson, Whitney D; Yates, Jane E; Hanlon Newell, Amy E; Olson, Susan B; Druker, Brian J; Bagby, Grover C

2012-07-12

Bone marrow failure is a nearly universal complication of Fanconi anemia. The proteins encoded by FANC genes are involved in DNA damage responses through the formation of a multisubunit nuclear complex that facilitates the E3 ubiquitin ligase activity of FANCL. However, it is not known whether loss of E3 ubiquitin ligase activity accounts for the hematopoietic stem cell defects characteristic of Fanconi anemia. Here we provide evidence that FANCL increases the activity and expression of β-catenin, a key pluripotency factor in hematopoietic stem cells. We show that FANCL ubiquitinates β-catenin with atypical ubiquitin chain extension known to have nonproteolytic functions. Specifically, β-catenin modified with lysine-11 ubiquitin chain extension efficiently activates a lymphocyte enhancer-binding factor-T cell factor reporter. We also show that FANCL-deficient cells display diminished capacity to activate β-catenin leading to reduced transcription of Wnt-responsive targets c-Myc and Cyclin D1. Suppression of FANCL expression in normal human CD34(+) stem and progenitor cells results in fewer β-catenin active cells and inhibits expansion of multilineage progenitors. Together, these results suggest that diminished Wnt/β-catenin signaling may be an underlying molecular defect in FANCL-deficient hematopoietic stem cells leading to their accelerated loss.

The Protective Effects of Curcumin on Obesity-Related Glomerulopathy Are Associated with Inhibition of Wnt/β-Catenin Signaling Activation in Podocytes

Directory of Open Access Journals (Sweden)

Bao-li Liu

2015-01-01

Full Text Available The present study investigated the effects of curcumin, one of the most important active ingredients of turmeric, on podocyte injury in vitro and obesity-related glomerulopathy (ORG in vivo. Cellular experiments in vitro showed that curcumin significantly antagonized leptin-induced downregulation of the mRNA and protein expression of podocyte-associated molecules including nephrin, podocin, podoplanin, and podocalyxin. Animal experiments in vivo showed that curcumin significantly reduced the body weight, Lee’s index, abdominal fat index, urinary protein excretion, and average glomerular diameter and significantly upregulated the mRNA and protein expressions of the above podocyte-associated molecules in ORG mice. Furthermore, the experiments in vitro and in vivo both displayed that curcumin could downregulate the mRNA and protein expressions of Wnt1, Wnt2b, Wnt6, and β-catenin and upregulate the phosphorylation level of β-catenin protein in podocytes and renal tissue. In conclusion, curcumin is able to alleviate the harmful reaction of leptin on podocytes and reduce the severity of ORG. The above protective effects are associated with the inhibition of Wnt/β-catenin signaling activation in podocytes.

Inhibition of estrogen-responsive gene activation by the retinoid X receptor beta: evidence for multiple inhibitory pathways.

Science.gov (United States)

Segars, J H; Marks, M S; Hirschfeld, S; Driggers, P H; Martinez, E; Grippo, J F; Brown, M; Wahli, W; Ozato, K

1993-04-01

The retinoid X receptor beta (RXR beta; H-2RIIBP) forms heterodimers with various nuclear hormone receptors and binds multiple hormone response elements, including the estrogen response element (ERE). In this report, we show that endogenous RXR beta contributes to ERE binding activity in nuclear extracts of the human breast cancer cell line MCF-7. To define a possible regulatory role of RXR beta regarding estrogen-responsive transcription in breast cancer cells, RXR beta and a reporter gene driven by the vitellogenin A2 ERE were transfected into estrogen-treated MCF-7 cells. RXR beta inhibited ERE-driven reporter activity in a dose-dependent and element-specific fashion. This inhibition occurred in the absence of the RXR ligand 9-cis retinoic acid. The RXR beta-induced inhibition was specific for estrogen receptor (ER)-mediated ERE activation because inhibition was observed in ER-negative MDA-MB-231 cells only following transfection of the estrogen-activated ER. No inhibition of the basal reporter activity was observed. The inhibition was not caused by simple competition of RXR beta with the ER for ERE binding, since deletion mutants retaining DNA binding activity but lacking the N-terminal or C-terminal domain failed to inhibit reporter activity. In addition, cross-linking studies indicated the presence of an auxiliary nuclear factor present in MCF-7 cells that contributed to RXR beta binding of the ERE. Studies using known heterodimerization partners of RXR beta confirmed that RXR beta/triiodothyronine receptor alpha heterodimers avidly bind the ERE but revealed the existence of another triiodothyronine-independent pathway of ERE inhibition. These results indicate that estrogen-responsive genes may be negatively regulated by RXR beta through two distinct pathways.

Very Bright CV discovered by MASTER-ICATE (Argentina)

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Saffe, C.; Levato, H.; Mallamaci, C.; Lopez, C.; Lipunov, F. Podest V.; Denisenko, D.; Gorbovskoy, E.; Tiurina, N.; Balanutsa, P.; Kornilov, V.; Belinski, A.; Shatskiy, N.; Chazov, V.; Kuznetsov, A.; Yecheistov, V.; Yurkov, V.; Sergienko, Y.; Varda, D.; Sinyakov, E.; Gabovich, A.; Ivanov, K.; Yazev, S.; Budnev, N.; Konstantinov, E.; Chuvalaev, O.; Poleshchuk, V.; Gress, O.; Frolova, A.; Krushinsky, V.; Zalozhnih, I.; Popov, A.; Bourdanov, A.; Parkhomenko, A.; Tlatov, A.; Dormidontov, D.; Senik, V.; Podvorotny, P.; Shumkov, V.; Shurpakov, S.

2013-06-01

MASTER-ICATE very wide-field camera (d=72mm f/1.2 lens + 11 Mpix CCD) located near San Juan, Argentina has discovered OT source at (RA, Dec) = 14h 20m 23.5s -48d 55m 40s on the combined image (exposure 275 sec) taken on 2013-06-08.048 UT. The OT unfiltered magnitude is 12.1m (limit 13.1m). There is no minor planet at this place. The OT is seen in more than 10 images starting from 2013-06-02.967 UT (275 sec exposure) when it was first detected at 12.4m.

Wnt/β-catenin signaling mediates the suppressive effects of diallyl trisulfide on colorectal cancer stem cells.

Science.gov (United States)

Zhang, Qi; Li, Xiao-Ting; Chen, Yue; Chen, Jia-Qi; Zhu, Jian-Yun; Meng, Yu; Wang, Xiao-Qian; Li, Yuan; Geng, Shan-Shan; Xie, Chun-Feng; Wu, Jie-Shu; Zhong, Cai-Yun; Han, Hong-Yu

2018-06-01

Cancer stem cells (CSCs) are responsible for colorectal cancer (CRC) initiation, growth, and metastasis. Garlic-derived organosulfur compound diallyl trisulfide (DATS) possesses cancer suppressive properties. Wnt/β-catenin signaling is a key target for CSCs inhibition. However, the interventional effect of DATS on colorectal CSCs has not been clarified. We aimed to illustrate the regulation of Wnt/β-catenin in DATS-induced colorectal CSCs inhibition. Serum-free medium culture was used to enrich colorectal CSCs. SW480 and DLD-1 sphere-forming cells were treated with different concentrations of DATS for 5 days; LiCl and β-catenin plasmids were used to stimulate the activity of Wnt/β-catenin pathway. The size and number of colonspheres were detected by tumorsphere formation assay; the expression of colorectal CSCs-related genes was detected by Western blotting and qRT-PCR; the capacities of colorectal CSCs proliferation and apoptosis were detected by Cell Counting Kit-8, Hoechst 33258 cell staining and flow cytometry, respectively. The levels of colorectal CSCs markers were elevated in the tumorspheres cells. DATS efficiently suppressed the activity of colorectal CSCs, as evidenced by reducing the size and number of colonspheres, decreasing the expression of colorectal CSCs markers, promoting apoptosis and inhibiting the proliferation of colorectal CSCs. Moreover, DATS suppressed the activity of Wnt/β-catenin pathway, while upregulation of Wnt/β-catenin diminished the inhibitory effect of DATS on colorectal CSCs. Wnt/β-catenin pathway mediates DATS-induced colorectal CSCs suppression. These findings support the use of DATS for targeting colorectal CSCs.

Lysosomal trafficking of β-catenin induced by the tea polyphenol epigallocatechin-3-gallate

International Nuclear Information System (INIS)

Dashwood, Wan-Mohaiza; Carter, Orianna; Al-Fageeh, Mohamed; Li, Qingjie; Dashwood, Roderick H.

2005-01-01

β-Catenin is a cadherin-binding protein involved in cell-cell adhesion, which also functions as a transcriptional activator when complexed in the nucleus with members of the T-cell factor (TCF)/lymphoid enhancer factor (LEF) family of proteins. There is considerable interest in mechanisms that down-regulate β-catenin, since this provides an avenue for the prevention of colorectal and other cancers in which β-catenin is frequently over-expressed. We show here that physiologically relevant concentrations of the tea polyphenol epigallocatechin-3-gallate (EGCG) inhibited β-catenin/TCF-dependent reporter activity in human embryonic kidney 293 cells transfected with wild type or mutant β-catenins, and there was a corresponding decrease in β-catenin protein levels in the nuclear, cytosolic and membrane-associated fractions. However, β-catenin accumulated as punctate aggregates in response to EGCG treatment, including in human colon cancer cells over-expressing β-catenin endogenously. Confocal microscopy studies revealed that the aggregated β-catenin in HEK293 cells was extra-nuclear and co-localized with lysosomes, suggesting that EGCG activated a pathway involving lysosomal trafficking of β-catenin. Lysosomal inhibitors leupeptin and transepoxysuccinyl-L-leucylamido(4-guanido)butane produced an increase in β-catenin protein in total cell lysates, without a concomitant increase in β-catenin transcriptional activity. These data provide the first evidence that EGCG facilitates the trafficking of β-catenin into lysosomes, presumably as a mechanism for sequestering β-catenin and circumventing further nuclear transport and activation of β-catenin/TCF/LEF signaling

Frequent Nuclear/Cytoplasmic Localization of β-Catenin without Exon 3 Mutations in Malignant Melanoma

Science.gov (United States)

Rimm, David L.; Caca, Karel; Hu, Gang; Harrison, Frank B.; Fearon, Eric R.

1999-01-01

β-Catenin has a critical role in E-cadherin-mediated cell-cell adhesion, and it also functions as a downstream signaling molecule in the wnt pathway. Mutations in the putative glycogen synthase kinase 3β phosphorylation sites near the β-catenin amino terminus have been found in some cancers and cancer cell lines. The mutations render β-catenin resistant to regulation by a complex containing the glycogen synthase kinase 3β, adenomatous polyposis coli, and axin proteins. As a result, β-catenin accumulates in the cytosol and nucleus and activates T-cell factor/lymphoid enhancing factor transcription factors. Previously, 6 of 27 melanoma cell lines were found to have β-catenin exon 3 mutations affecting the N-terminal phosphorylation sites (Rubinfeld B, Robbins P, Elgamil M, Albert I, Porfiri E, Polakis P: Stabilization of beta-catenin by genetic defects in melanoma cell lines. Science 1997, 275:1790–1792). To assess the role of β-catenin defects in primary melanomas, we undertook immunohistochemical and DNA sequencing studies in 65 melanoma specimens. Nuclear and/or cytoplasmic localization of β-catenin, a potential indicator of wnt pathway activation, was seen focally within roughly one third of the tumors, though a clonal somatic mutation in β-catenin was found in only one case (codon 45 Ser→Pro). Our findings demonstrate that β-catenin mutations are rare in primary melanoma, in contrast to the situation in melanoma cell lines. Nonetheless, activation of β-catenin, as indicated by its nuclear and/or cytoplasmic localization, appears to be frequent in melanoma, and in some cases, it may reflect focal and transient activation of the wnt pathway within the tumor. PMID:10027390

Upregulation of MiR-212 Inhibits Migration and Tumorigenicity and Inactivates Wnt/β-Catenin Signaling in Human Hepatocellular Carcinoma.

Science.gov (United States)

Jia, Pengbo; Wei, Guangbing; Zhou, Cancan; Gao, Qi; Wu, Yunhua; Sun, Xuejun; Li, Xuqi

2018-01-01

MicroRNAs are involved in hepatocellular carcinoma metastasis, a principal cause of hepatocellular carcinoma-related death in patients worldwide. MiR-212 is a microRNA that has been identified in several types of cancers and is postulated to influence cell signaling and subsequent malignant pathogenesis. Despite emerging reports suggesting that miR-212 plays a significant role in the onset, progression, and migration of these types of malignant tumors, its involvement in the development of hepatocellular carcinoma has not been fully elucidated. Quantitative reverse transcription polymerase chain reaction, wound healing, transwell migration and invasion assays, Western blotting, and xenograft tumor growth models were performed to test the expression levels and functions of miR-212 in hepatocellular carcinoma. Luciferase reporter assay, quantitative reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-212. In this study, we identify significant repression of miR-212 in hepatocellular carcinoma and demonstrate that overexpression of miR-212 inhibits the migration of hepatocellular carcinoma cells in vitro and in vivo. Furthermore, we identify forkhead box M1, whose expression is inversely related to that of miR-212, as a direct target of miR-212. Additionally, reexpression of forkhead box M1 rescues the miR-212-mediated inhibition of cell migration. We observed that inhibition of miR-212 activates forkhead box M1 but inhibits the Wnt/β-catenin pathway by suppressing Wnt, LEF-1, c-Myc, and nuclear β-catenin. Finally, in vivo studies confirmed the inhibitory effect of miR-212 on hepatocellular carcinoma growth. Our present findings indicate that miR-212 is a potential prognostic biomarker of hepatocellular carcinoma and that the miR-212/forkhead box M1 regulatory axis may represent a new therapeutic objective for hepatocellular carcinoma treatment.

Morin ameliorates chemically induced liver fibrosis in vivo and inhibits stellate cell proliferation in vitro by suppressing Wnt/β-catenin signaling

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MadanKumar, Perumal; NaveenKumar, Perumal; Manikandan, Samidurai [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India); Devaraj, Halagowder [Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India); NiranjaliDevaraj, Sivasithamparam, E-mail: niranjali@yahoo.com [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India)

2014-06-01

The anti-fibrotic effect of morin was examined in LX-2 cells (culture-activated human hepatic stellate cells) and in diethylnitrosamine induced rat model of liver fibrosis. The in vitro study was designed to determine whether morin affects the survival of cultured LX-2 cells, while the in vivo study was designed to evaluate the antioxidant and anti-fibrotic efficacy of morin on diethylnitrosamine induced liver fibrosis in male albino Wistar rat. The activities of liver function enzymes in serum, liver lipid peroxide levels, activities of serum antioxidant enzymes and liver architecture were monitored to cast light on the antioxidant and hepatoprotective nature of morin. To establish the anti-fibrotic effects of morin, the levels of key Wnt signaling molecules which are strongly associated with the signal transduction pathway of HSC activation were measured. Overall, from the in vitro results, it was observed that morin at 50 μM concentration inhibited the proliferation of cultured LX-2 cells, inhibited Wnt signaling and induced G1 cell cycle arrest. The in vivo results further confirmed that morin by downregulating the expressions of GSK-3β, β-catenin and cyclin D1 ameliorated DEN-induced liver fibrosis. Hence morin could be employed as a promising chemopreventive natural supplement for liver fibrosis. - Highlights: • In vivo and in vitro results revealed the active participation of Wnt signaling. • Morin at 50 μM inhibited LX-2 cell proliferation by suppressing Wnt signaling. • Morin exhibited hepatoprotective effects against DEN induced liver fibrosis. • Morin inhibited HSC activation in vivo by downregulating Wnt/β-catenin signaling.

Restoration of anatomical continuity after spinal cord transection depends on Wnt/β-catenin signaling in larval zebrafish

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Daniel Wehner

2018-02-01

Full Text Available This data article contains descriptive and experimental data on spinal cord regeneration in larval zebrafish and its dependence on Wnt/β-catenin signaling. Analyzing spread of intraspinally injected fluorescent dextran showed that anatomical continuity is rapidly restored after complete spinal cord transection. Pharmacological interference with Wnt/β-catenin signaling (IWR-1 impaired restoration of spinal continuity. For further details and experimental findings please refer to the research article by Wehner et al. Wnt signaling controls pro-regenerative Collagen XII in functional spinal cord regeneration in zebrafish (Wehner et al., 2017 [1]. Keywords: Wnt, Beta-catenin, Regeneration, Spinal cord, Zebrafish

Vitamin D Is a Multilevel Repressor of Wnt/β-Catenin Signaling in Cancer Cells

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Larriba, María Jesús; González-Sancho, José Manuel; Barbáchano, Antonio; Niell, Núria; Ferrer-Mayorga, Gemma; Muñoz, Alberto, E-mail: amunoz@iib.uam.es [Instituto de Investigaciones Biomédicas “Alberto Sols”, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Arturo Duperier 4, Madrid 28029 (Spain)

2013-10-21

The Wnt/β-catenin signaling pathway is abnormally activated in most colorectal cancers and in a proportion of other neoplasias. This activation initiates or contributes to carcinogenesis by regulating the expression of a large number of genes in tumor cells. The active vitamin D metabolite 1α,25-dihydroxyvitamin D{sub 3} (1,25(OH){sub 2}D{sub 3}) inhibits Wnt/β-catenin signaling by several mechanisms at different points along the pathway. Additionally, paracrine actions of 1,25(OH){sub 2}D{sub 3} on stromal cells may also repress this pathway in neighbouring tumor cells. Here we review the molecular basis for the various mechanisms by which 1,25(OH){sub 2}D{sub 3} antagonizes Wnt/β-catenin signaling, preferentially in human colon carcinoma cells, and the consequences of this inhibition for the phenotype and proliferation rate. The effect of the vitamin D system on Wnt/β-catenin signaling and tumor growth in animal models will also be commented in detail. Finally, we revise existing data on the relation between vitamin D receptor expression and vitamin D status and the expression of Wnt/β-catenin pathway genes and targets in cancer patients.

A silyl andrographolide analogue suppresses Wnt/β-catenin signaling pathway in colon cancer.

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Reabroi, Somrudee; Chairoungdua, Arthit; Saeeng, Rungnapha; Kasemsuk, Teerapich; Saengsawang, Witchuda; Zhu, Weiming; Piyachaturawat, Pawinee

2018-05-01

Hyperactivation of Wnt/β-catenin signaling implicated in oncogenesis of colorectal cancer (CRC) is a potential molecular target for chemotherapy. An andrographolide analogue, 3A.1 (19-tert-butyldiphenylsilyl-8, 17-epoxy andrographolide) has previously been reported to be potently cytotoxic toward cancer cells by unknown molecular mechanisms. The present study explored the anti-cancer activity of analogue 3A.1 on Wnt/β-catenin signaling in colon cancer cells (HT29 cells) which were more sensitive to the others (HCT116 and SW480 cells). Analogue 3A.1 inhibited viability of HT29 cells with IC 50 value of 11.1 ± 1.4 μM at 24 h, which was more potent than that of the parent andrographolide. Analogue 3A.1 also suppressed the proliferation of HT29 cells and induced cell apoptosis in a dose-dependent manner. Its apoptotic activity was accompanied with increased expressions of proteins related to DNA damages; PARP-1 and γ-H2AX. In addition, analogue 3A.1 significantly inhibited T-cell factor and lymphoid enhancer factor (TCF/LEF) promoter activity of Wnt/β-catenin signaling. Accordingly, the expressions of Wnt target genes and β-catenin protein were suppressed. Moreover, analogue 3A.1 increased the activity of GSK-3β kinase, which is a negative regulator responsible for degradation of intracellular β-catenin. This mode of action was further supported by the absence of the effects after treatment with a GSK-3β inhibitor, and over-expression of a mutant β-catenin (S33Y). Our findings reveal, for the first time, an insight into the molecular mechanism of the anti-cancer activity of analogue 3A.1 through the inhibition of Wnt/β-catenin/GSK-3β pathway and provide a therapeutic potential of the andrographolide analogue 3A.1 in CRC treatment. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

GSK-3beta inhibition enhances sorafenib-induced apoptosis in melanoma cell lines.

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Panka, David J; Cho, Daniel C; Atkins, Michael B; Mier, James W

2008-01-11

Glycogen synthase kinase-3beta (GSK-3beta) can participate in the induction of apoptosis or, alternatively, provide a survival signal that minimizes cellular injury. We previously demonstrated that the multikinase inhibitor sorafenib induces apoptosis in melanoma cell lines. In this report, we show that sorafenib activates GSK-3beta in multiple subcellular compartments and that this activation undermines the lethality of the drug. Pharmacologic inhibition and/or down-modulation of the kinase enhances sorafenib-induced apoptosis as determined by propidium iodide staining and by assessing the mitochondrial release of apoptosis-inducing factor and Smac/DIABLO. Conversely, the forced expression of a constitutively active form of the enzyme (GSK-3beta(S9A)) protects the cells from the apoptotic effects of the drug. This protective effect is associated with a marked increase in basal levels of Bcl-2, Bcl-x(L), and survivin and a diminution in the degree to which these anti-apoptotic proteins are down-modulated by sorafenib exposure. Sorafenib down-modulates the pro-apoptotic Bcl-2 family member Noxa in cells with high constitutive GSK-3beta activity. Pharmacologic inhibition of GSK-3beta prevents the disappearance of Noxa induced by sorafenib and enhances the down-modulation of Mcl-1. Down-modulation of Noxa largely eliminates the enhancing effect of GSK-3 inhibition on sorafenib-induced apoptosis. These data provide a strong rationale for the use of GSK-3beta inhibitors as adjuncts to sorafenib treatment and suggest that preservation of Noxa may contribute to their efficacy.

Elevated β-catenin activity contributes to carboplatin resistance in A2780cp ovarian cancer cells

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Barghout, Samir H. [Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada); Zepeda, Nubia; Xu, Zhihua [Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada); Steed, Helen [Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada); Lee, Cheng-Han [Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada); Fu, YangXin, E-mail: yangxin@ualberta.ca [Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada); Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB (Canada)

2015-12-04

Ovarian cancer is the fifth leading cause of cancer-related mortalities in women. Epithelial ovarian cancer (EOC) represents approximately 90% of all ovarian malignancies. Most EOC patients are diagnosed at advanced stages and current chemotherapy regimens are ineffective against advanced EOC due to the development of chemoresistance. It is important to better understand the molecular mechanisms underlying acquired resistance to effectively manage this disease. In this study, we examined the expression of the Wnt/β-catenin signaling components in the paired cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) EOC cell lines. Our results showed that several negative regulators of Wnt signaling are downregulated, whereas a few Wnt ligands and known Wnt/β-catenin target genes are upregulated in A2780cp cells compared to A2780s cells, suggesting that Wnt/β-catenin signaling is more active in A2780cp cells. Further analysis revealed nuclear localization of β-catenin and higher β-catenin transcriptional activity in A2780cp cells compared to A2780s cells. Finally, we demonstrated that chemical inhibition of β-catenin transcriptional activity by its inhibitor CCT036477 sensitized A2780cp cells to carboplatin, supporting a role for β-catenin in carboplatin resistance in A2780cp cells. In conclusion, our data suggest that increased Wnt/β-catenin signaling activity contributes to carboplatin resistance in A2780cp cells. - Highlights: • Wnt ligands and target genes are upregulated in cisplatin resistant A2780cp cells. • Negative regulators of Wnt signaling are down-regulated in A2780cp cells. • β-catenin transcriptional activity is higher in A2780cp cells compared to A2780s cells. • Inhibition of β-catenin activity increases carboplatin cytotoxicity in A2780cp cells.

Elevated β-catenin activity contributes to carboplatin resistance in A2780cp ovarian cancer cells

International Nuclear Information System (INIS)

Barghout, Samir H.; Zepeda, Nubia; Xu, Zhihua; Steed, Helen; Lee, Cheng-Han; Fu, YangXin

2015-01-01

Ovarian cancer is the fifth leading cause of cancer-related mortalities in women. Epithelial ovarian cancer (EOC) represents approximately 90% of all ovarian malignancies. Most EOC patients are diagnosed at advanced stages and current chemotherapy regimens are ineffective against advanced EOC due to the development of chemoresistance. It is important to better understand the molecular mechanisms underlying acquired resistance to effectively manage this disease. In this study, we examined the expression of the Wnt/β-catenin signaling components in the paired cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) EOC cell lines. Our results showed that several negative regulators of Wnt signaling are downregulated, whereas a few Wnt ligands and known Wnt/β-catenin target genes are upregulated in A2780cp cells compared to A2780s cells, suggesting that Wnt/β-catenin signaling is more active in A2780cp cells. Further analysis revealed nuclear localization of β-catenin and higher β-catenin transcriptional activity in A2780cp cells compared to A2780s cells. Finally, we demonstrated that chemical inhibition of β-catenin transcriptional activity by its inhibitor CCT036477 sensitized A2780cp cells to carboplatin, supporting a role for β-catenin in carboplatin resistance in A2780cp cells. In conclusion, our data suggest that increased Wnt/β-catenin signaling activity contributes to carboplatin resistance in A2780cp cells. - Highlights: • Wnt ligands and target genes are upregulated in cisplatin resistant A2780cp cells. • Negative regulators of Wnt signaling are down-regulated in A2780cp cells. • β-catenin transcriptional activity is higher in A2780cp cells compared to A2780s cells. • Inhibition of β-catenin activity increases carboplatin cytotoxicity in A2780cp cells.

Expression and interaction of different catenins in colorectal carcinoma cells

Czech Academy of Sciences Publication Activity Database

Kučerová, Dana; Šloncová, Eva; Tuháčková, Zdena; Vojtěchová, Martina; Sovová, Vlasta

2001-01-01

Roč. 8, č. 6 (2001), s. 695-698 ISSN 1107-3756 R&D Projects: GA ČR GA301/00/0269; GA ČR GV312/96/K204 Institutional research plan: CEZ:AV0Z5052915 Keywords : colorectal carcinoma cells * beta-catenin * p120 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.689, year: 2001

Immunohistochemical study of β-catenin in experimental colon carcinoma of rat

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Y Doustar

2009-08-01

Full Text Available Colorectal adenocarcinoma is one of the most prevalent and treatable malignancies of the gastrointestinal tract. Recent studies on colorectal neoplasia indicates β-catenin gene mutation and its intranuclear accumulation inside hyperplastic cells. Therefore, β-catenin may be an important prognosis and diagnostic index of this disease. The aim of this study is to evaluate the nuclear beta-catenin expression in hyperplastic cells of colon following treatment with 1,2-dimethylhydrazine. In this study, 56 wistar male rats with the age of 12 weeks and body weight of 200-300g were selected and randomly allocated into two equal treatment and control groups. In the treatment group, two subcutaneous injections of 1,2-dimethylhydrazine every week at a dose rate of 40 mg/kg were used for 4 weeks to induce colon carcinoma. The control group was given normal saline solution similarly. After 8 weeks, tissues samples of distal colon were collected from both groups for preparation of tissue sections and immunohistochemistry. Immunohistopathological study of samples revealed that nuclear β-catenin expression in the treatment group was significantly higher than the control group (p

NRAGE induces β-catenin/Arm O-GlcNAcylation and negatively regulates Wnt signaling

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Chen, Yuxin; Jin, Lei; Xue, Bin; Jin, Dong; Sun, Fenyong; Wen, Chuanjun

2017-01-01

The Wnt pathway is crucial for animal development, as well as tumor formation. Understanding the regulation of Wnt signaling will help to elucidate the mechanism of the cell cycle, cell differentiation and tumorigenesis. It is generally accepted that in response to Wnt signals, β-catenin accumulates in the cytoplasm and is imported into the nucleus where it recruits LEF/TCF transcription factors to activate the expression of target genes. In this study, we report that human NRAGE, a neurotrophin receptor p75 (p75NTR) binding protein, markedly suppresses the expression of genes activated by the Wnt pathway. Consistent with this finding, loss of function of NRAGE by RNA interference (RNAi) activates the Wnt pathway. Moreover, NRAGE suppresses the induction of axis duplication by microinjected β-catenin in Xenopus embryos. To our surprise, NRAGE induces nuclear localization of β-catenin and increases its DNA binding ability. Further studies reveal that NRAGE leads to the modification of β-catenin/Arm with O-linked beta-N-acetylglucosamine (O-GlcNAc), and failure of the association between β-catenin/Arm and pygopus(pygo) protein, which is required for transcriptional activation of Wnt target genes. Therefore, our findings suggest a novel mechanism for regulating Wnt signaling. - Highlights: • NRAGE suppresses the expressions of Wnt pathway downstream genes. • NRAGE induces nuclear localization of β-catenin and increases its DNA binding ability. • NRAGE activity leads to the O-GlcNAcylation of β-catenin.

Down-regulation of E-cadherin and catenins in human pituitary growth hormone-producing adenomas.

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Sano, Toshiaki; Rong, Qian Zhi; Kagawa, Noriko; Yamada, Shozo

2004-01-01

Growth hormone (GH)-producing pituitary adenomas can be ultrastructurally divided into two major types: densely granulated and sparsely granulated. The latter type of adenoma characteristically exhibits globular accumulations of cytokeratin filaments known as fibrous bodies, which are immunohistochemically identifiable as juxtanuclear dot-like immunoreactivity. We hypothesize that the formation of fibrous body might be related to dysfunction of adhesion molecules, because of the functional relationship between intermediate filaments and the cadherin-catenin complex and frequent observation of loss of cohesiveness of the adenoma cells. Our recent immunohistochemical study showed that expression of E-cadherin and its undercoat proteins, alpha-, beta- and gamma-catenin, in GH cell adenomas with prominent fibrous bodies was significantly reduced compared with GH cell adenomas without fibrous bodies and the normal adenohypophysial cells. Although no mutation of exon 3 of the beta-catenin gene was found in any GH cell adenomas with fibrous bodies, methylation-specific polymerase chain reaction analysis revealed that the E-cadherin promoter region was methylated in 37.5% of these adenomas, two of which displayed total methylation, but not in GH cell adenomas without fibrous bodies. We conclude that the decreased expression of the E-cadherin-catenin complex and methylation of the E-cadherin gene promoter region are events associated with the formation of fibrous bodies in GH cell adenomas. It remains to be clarified to explain the mechanism by which down-regulation of adhesion molecules is involved in the abnormal assembly of intermediate filaments.

Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin

International Nuclear Information System (INIS)

Sopjani, Mentor; Alesutan, Ioana; Wilmes, Jan; Dermaku-Sopjani, Miribane; Lam, Rebecca S.; Koutsouki, Evgenia; Jakupi, Muharrem; Foeller, Michael; Lang, Florian

2010-01-01

Research highlights: → The oncogenic transcription factor β-catenin stimulates the Na + /K + -ATPase. → β-Catenin stimulates SGLT1 dependent Na + , glucose cotransport. → The effects are independent of transcription. → β-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: β-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. β-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that β-catenin influences membrane transport. To this end, β-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of β-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na + /K + -ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of β-catenin on the endogenous Na + /K + -ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of β-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of β-catenin expression. The stimulating effect of β-catenin on both Na + /K + ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of β-catenin, i.e. the regulation of transport.

Knockdown of TC-1 enhances radiosensitivity of non-small cell lung cancer via the Wnt/β-catenin pathway.

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Wu, Dapeng; Li, Lei; Yan, Wei

2016-04-15

Thyroid cancer 1 (TC-1, C8ofr4) is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blotin vitroandin vivo Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results fromin vitroandin vivostudies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway. © 2016. Published by The Company of Biologists Ltd.

The critical role of EGF-β-catenin signaling in the epithelial-mesenchymal transition in human glioblastoma

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Wang X

2017-05-01

Full Text Available Xingqiang Wang, Shanshi Wang, Xiaolong Li, Shigang Jin, Feng Xiong, Xin Wang Department of Neurosurgery, People’s Hospital of Rizhao, Jining Medical University, Rizhao, China Abstract: To date, β-catenin has been reported to be implicated in mediating the epithelial-mesenchymal transition (EMT in a variety of human cancers, which can be triggered by EGF. However, the mechanisms underlying EGF-β-catenin pathway-induced EMT of glioblastoma multiforme (GBM have not been reported previously. In the present study, immunohistochemistry, reverse transcription polymerase chain reaction, and Western blot were applied to investigate the effect of EGF-β-catenin pathway on EMT of GBM. Here, we identified that β-catenin mRNA and protein levels were up-regulated in GBM tissues and four kinds of glioblastoma cell lines, including T98G, A172, U87, and U251 cells, compared with normal brain tissue and astrocytes. In U87 cell line, inhibition of β-catenin by siRNA suppressed EGF-induced proliferation, migration, invasiveness, and the expression of EMT activators (Snail and Slug. In addition, the expression of epithelial markers (E-cadherin was up-regulated and the expression of mesenchymal markers (N-cadherin and MMP9 was down-regulated. Finally, inhibitor of PI3K/Akt signaling pathways inactivated the EGF-β-catenin-induced EMT. In conclusion, β-catenin-EMT pathway induced by EGF is important for GBM progression by the PI3K/Akt pathways. Inhibition of β-catenin leads to suppression of EGF pathway-induced EMT, which provides a new way to treat GBM patients. Keywords: EGF, β-catenin, EMT, GBM

TGF-beta3 is expressed in taste buds and inhibits proliferation of primary cultured taste epithelial cells.

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Nakamura, Shin-ichi; Kawai, Takayuki; Kamakura, Takashi; Ookura, Tetsuya

2010-01-01

Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.

GPR84 sustains aberrant β-catenin signaling in leukemic stem cells for maintenance of MLL leukemogenesis.

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Dietrich, Philipp A; Yang, Chen; Leung, Halina H L; Lynch, Jennifer R; Gonzales, Estrella; Liu, Bing; Haber, Michelle; Norris, Murray D; Wang, Jianlong; Wang, Jenny Yingzi

2014-11-20

β-catenin is required for establishment of leukemic stem cells (LSCs) in acute myeloid leukemia (AML). Targeted inhibition of β-catenin signaling has been hampered by the lack of pathway components amenable to pharmacologic manipulation. Here we identified a novel β-catenin regulator, GPR84, a member of the G protein-coupled receptor family that represents a highly tractable class of drug targets. High GPR84 expression levels were confirmed in human and mouse AML LSCs compared with hematopoietic stem cells (HSCs). Suppression of GPR84 significantly inhibited cell growth by inducing G1-phase cell-cycle arrest in pre-LSCs, reduced LSC frequency, and impaired reconstitution of stem cell-derived mixed-lineage leukemia (MLL) AML, which represents an aggressive and drug-resistant subtype of AML. The GPR84-deficient phenotype in established AML could be rescued by expression of constitutively active β-catenin. Furthermore, GPR84 conferred a growth advantage to Hoxa9/Meis1a-transduced stem cells. Microarray analysis demonstrated that GPR84 significantly upregulated a small set of MLL-fusion targets and β-catenin coeffectors, and downregulated a hematopoietic cell-cycle inhibitor. Altogether, our data reveal a previously unrecognized role of GPR84 in maintaining fully developed AML by sustaining aberrant β-catenin signaling in LSCs, and suggest that targeting the oncogenic GPR84/β-catenin signaling axis may represent a novel therapeutic strategy for AML. © 2014 by The American Society of Hematology.

A randomized controlled comparison of integrative cognitive-affective therapy (ICAT) and enhanced cognitive-behavioral therapy (CBT-E) for bulimia nervosa.

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Wonderlich, S A; Peterson, C B; Crosby, R D; Smith, T L; Klein, M H; Mitchell, J E; Crow, S J

2014-02-01

The purpose of this investigation was to compare a new psychotherapy for bulimia nervosa (BN), integrative cognitive-affective therapy (ICAT), with an established treatment, 'enhanced' cognitive-behavioral therapy (CBT-E). Eighty adults with symptoms of BN were randomized to ICAT or CBT-E for 21 sessions over 19 weeks. Bulimic symptoms, measured by the Eating Disorder Examination (EDE), were assessed at baseline, at the end of treatment (EOT) and at the 4-month follow-up. Treatment outcome, measured by binge eating frequency, purging frequency, global eating disorder severity, emotion regulation, self-oriented cognition, depression, anxiety and self-esteem, was determined using generalized estimating equations (GEEs), logistic regression and a general linear model (intent-to-treat). Both treatments were associated with significant improvement in bulimic symptoms and in all measures of outcome, and no statistically significant differences were observed between the two conditions at EOT or follow-up. Intent-to-treat abstinence rates for ICAT (37.5% at EOT, 32.5% at follow-up) and CBT-E (22.5% at both EOT and follow-up) were not significantly different. ICAT was associated with significant improvements in bulimic and associated symptoms that did not differ from those obtained with CBT-E. This initial randomized controlled trial of a new individual psychotherapy for BN suggests that targeting emotion and self-oriented cognition in the context of nutritional rehabilitation may be efficacious and worthy of further study.

Green tea polyphenol, (−)-epigallocatechin-3-gallate, induces toxicity in human skin cancer cells by targeting β-catenin signaling

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Singh, Tripti [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Katiyar, Santosh K., E-mail: skatiyar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Birmingham Veterans Affairs Medical Center, Birmingham, AL 35233 (United States)

2013-12-01

The green tea polyphenol, (−)-epigallocatechin-3-gallate (EGCG), has been shown to have anti-carcinogenic effects in several skin tumor models, and efforts are continued to investigate the molecular targets responsible for its cytotoxic effects to cancer cells. Our recent observation that β-catenin is upregulated in skin tumors suggested the possibility that the anti-skin carcinogenic effects of EGCG are mediated, at least in part, through its effects on β-catenin signaling. We have found that treatment of the A431 and SCC13 human skin cancer cell lines with EGCG resulted in reduced cell viability and increased cell death and that these cytotoxic effects were associated with inactivation of β-catenin signaling. Evidence of EGCG-induced inactivation of β-catenin included: (i) reduced accumulation of nuclear β-catenin; (ii) enhanced levels of casein kinase1α, reduced phosphorylation of glycogen synthase kinase-3β, and increased phosphorylation of β-catenin on critical serine{sup 45,33/37} residues; and (iii) reduced levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are down-stream targets of β-catenin. Treatment of cells with prostaglandin E2 (PGE{sub 2}) enhanced the accumulation of β-catenin and enhanced β-catenin signaling. Treatment with either EGCG or an EP2 antagonist (AH6809) reduced the PGE{sub 2}-enhanced levels of cAMP, an upstream regulator of β-catenin. Inactivation of β-catenin by EGCG resulted in suppression of cell survival signaling proteins. siRNA knockdown of β-catenin in A431 and SCC13 cells reduced cell viability. Collectively, these data suggest that induction of cytotoxicity in skin cancer cells by EGCG is mediated by targeting of β-catenin signaling and that the β-catenin signaling is upregulated by inflammatory mediators. - Highlights: • EGCG inhibits cancer cell viability through inactivation of β-catenin signaling. • Inactivation of β-catenin involves the downregulation of inflammatory mediators. • EGCG

CD147 regulates cancer migration via direct interaction with Annexin A2 and DOCK3-β-catenin-WAVE2 signaling.

Science.gov (United States)

Cui, Hong-Yong; Wang, Shi-Jie; Miao, Ji-Yu; Fu, Zhi-Guang; Feng, Fei; Wu, Jiao; Yang, Xiang-Min; Chen, Zhi-Nan; Jiang, Jian-Li

2016-02-02

The acquisition of inappropriate migratory feature is crucial for tumor metastasis. It has been suggested that CD147 and Annexin A2 are involved in regulating tumor cell movement, while the regulatory mechanisms are far from clear. In this study, we demonstrated that CD147 physically interacted with the N-terminal domain of Annexin A2 and decreased Annexin A2 phosphorylation on tyrosine 23. In vitro kinase assay showed that the I domain of CD147 was indispensable for CD147-mediated downregulation of Annexin A2 phosphorylation by Src. Furthermore, we determined that p-Annexin A2 promoted the expression of dedicator of cytokinesis 3 (DOCK3) and DOCK3 blocked β-catenin nuclear translocation, resulting in inhibition of β-catenin signaling. In addition, DOCK3 inhibited lamellipodium dynamics and tumor cell movement. Also, we found that β-catenin signaling increased WAVE2 expression. Therefore, DOCK3 was characterized as a negative regulator of WAVE2 expression via inhibiting β-catenin signaling. Our study provides the first evidence that CD147 promotes tumor cell movement and metastasis via direct interaction with Annexin A2 and DOCK3-β-catenin-WAVE2 signaling axis.

Role of MiR-3619-5p in β-Catenin-Mediated Non-Small Cell Lung Cancer Growth and Invasion

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Xuecai Niu

2015-10-01

Full Text Available Background/Aims: The malignancy of non-small cell lung cancer (NSCLC is largely due to its fast growth and invasion. WNT/β-catenin signaling plays a critical role in regulating NSCLC carcinogenesis. Hence, suppression of β-catenin signal transduction in NSCLC cells may improve the therapeutic outcome. Methods: We analyzed the levels of β-catenin and miR-3619-5p in NSCLC specimens, compared to paired non-tumor normal lung tissue (NT. We did Bioinformatics analyses on the binding sites of 3'-UTR of β-catenin mRNA by miR-3619-5p. We modified the levels of miR-3619-5p in NSCLC cells and examined their effects on β-catenin levels, and on the growth and invasion of NSCLC cells in an MTT assay and a transwell cell migration assay, respectively. Results: NSCLC specimens had significant higher levels of β-catenin, and significantly lower levels of miR-3619-5p, compared to NT. The levels of β-catenin and miR-3619-5p were inversely correlated in NSCLC specimens. Bioinformatics analyses showed that miR-3619-5p bound to 3'-UTR of β-catenin mRNA in NSCLC cells to inhibit its translation. Overexpression of miR-3619-5p decreased β-catenin protein, while depletion of miR-3619-5p increased β-catenin protein in NSCLC cells, without altering β-catenin mRNA levels. Overexpression of miR-3619-5p in NSCLC cells inhibited cell growth and invasion, while depletion of miR-3619-5p in NSCLC lines increased cell growth and invasion. Conclusion: Our data demonstrate a previously unappreciated role for miR-3619-5p in suppression of β-catenin-mediated cancer growth and invasion in NSCLC cells, and highlight miR-3619-5p as a novel cancer suppressor in NSCLC.

Molecular interactions between MUC1 epithelial mucin, β-catenin, and CagA proteins

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Wei eGuang

2012-05-01

Full Text Available Interleukin (IL-8-driven neutrophil infiltration of the gastric mucosa is pathognomonic of persistent Helicobacter pylori infection. Our prior study showed that ectopic over-expression of MUC1 in human AGS gastric epithelial cells reduced H. pylori-stimulated IL-8 production compared with cells expressing MUC1 endogenously. Conversely, Muc1 knockout (Muc1-/- mice displayed an increased level of transcripts encoding the keratinocyte chemoattractant (KC, the murine equivalent of human IL-8, in gastric mucosa compared with Muc1(+/+ mice during experimental H. pylori infection. The current study tested the hypothesis that a decreased IL-8 level observed following MUC1 over-expression is mediated through the ability of MUC1 to associate with β-catenin, thereby inhibiting H. pylori-induced β-catenin nuclear translocation. Increased neutrophil infiltration of the gastric mucosa of H. pylori-infected Muc1(-/- mice was observed compared with Muc1(+/+ wild type littermates, thus defining the functional consequences of increased KC expression in the Muc1-null animals. Protein co-immunoprecipitation (coIP studies using lysates of untreated or H. pylori-treated AGS cells demonstrated that (a MUC1 formed a coIP complex with β-catenin and CagA, (b MUC1 over-expression reduced CagA/β-catenin coIP, and (c in the absence of MUC1 over-expression, H. pylori infection increased the nuclear level of β-catenin, (d whereas MUC1 over-expression decreased bacteria-driven β-catenin nuclear localization. These results suggest that manipulation of MUC1 expression in gastric epithelia may be an effective therapeutic strategy to inhibit H. pylori-dependent IL-8 production, neutrophil infiltration, and stomach inflammation.

Use of an activated beta-catenin to identify Wnt pathway target genes in caenorhabditis elegans, including a subset of collagen genes expressed in late larval development.

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Jackson, Belinda M; Abete-Luzi, Patricia; Krause, Michael W; Eisenmann, David M

2014-04-16

The Wnt signaling pathway plays a fundamental role during metazoan development, where it regulates diverse processes, including cell fate specification, cell migration, and stem cell renewal. Activation of the beta-catenin-dependent/canonical Wnt pathway up-regulates expression of Wnt target genes to mediate a cellular response. In the nematode Caenorhabditis elegans, a canonical Wnt signaling pathway regulates several processes during larval development; however, few target genes of this pathway have been identified. To address this deficit, we used a novel approach of conditionally activated Wnt signaling during a defined stage of larval life by overexpressing an activated beta-catenin protein, then used microarray analysis to identify genes showing altered expression compared with control animals. We identified 166 differentially expressed genes, of which 104 were up-regulated. A subset of the up-regulated genes was shown to have altered expression in mutants with decreased or increased Wnt signaling; we consider these genes to be bona fide C. elegans Wnt pathway targets. Among these was a group of six genes, including the cuticular collagen genes, bli-1 col-38, col-49, and col-71. These genes show a peak of expression in the mid L4 stage during normal development, suggesting a role in adult cuticle formation. Consistent with this finding, reduction of function for several of the genes causes phenotypes suggestive of defects in cuticle function or integrity. Therefore, this work has identified a large number of putative Wnt pathway target genes during larval life, including a small subset of Wnt-regulated collagen genes that may function in synthesis of the adult cuticle.

3,5,4′-Trimethoxystilbene, a natural methoxylated analog of resveratrol, inhibits breast cancer cell invasiveness by downregulation of PI3K/Akt and Wnt/β-catenin signaling cascades and reversal of epithelial–mesenchymal transition

International Nuclear Information System (INIS)

Tsai, Jie-Heng; Hsu, Li-Sung; Lin, Chih-Li; Hong, Hui-Mei; Pan, Min-Hsiung; Way, Tzong-Der; Chen, Wei-Jen

2013-01-01

The molecular basis of epithelial–mesenchymal transition (EMT) functions as a potential therapeutic target for breast cancer because EMT may endow breast tumor-initiating cells with stem-like characteristics and enable the dissemination of breast cancer cells. We have recently verified the antitumor activity of 3,5,4′-trimethoxystilbene (MR-3), a naturally methoxylated derivative of resveratrol, in colorectal cancer xenografts via an induction of apoptosis. The effect of MR-3 on EMT and the invasiveness of human MCF-7 breast adenocarcinoma cell line were also explored. We found that MR-3 significantly increased epithelial marker E-cadherin expression and triggered a cobblestone-like morphology of MCF-7 cells, while reciprocally decreasing the expression of mesenchymal markers, such as snail, slug, and vimentin. In parallel with EMT reversal, MR-3 downregulated the invasion and migration of MCF-7 cells. Exploring the action mechanism of MR-3 on the suppression of EMT and invasion indicates that MR-3 markedly reduced the expression and nuclear translocation of β-catenin, accompanied with the downregulation of β-catenin target genes and the increment of membrane-bound β-catenin. These results suggest the involvement of Wnt/β-catenin signaling in the MR-3-induced EMT reversion of MCF-7 cells. Notably, MR-3 restored glycogen synthase kinase-3β activity by inhibiting the phosphorylation of Akt, the event required for β-catenin destruction via a proteasome-mediated system. Overall, these findings indicate that the anti-invasive activity of MR-3 on MCF-7 cells may result from the suppression of EMT via down-regulating phosphatidylinositol 3-kinase (PI3K)/AKT signaling, and consequently, β-catenin nuclear translocation. These occurrences ultimately lead to the blockage of EMT and the invasion of breast cancer cells. - Highlights: • MR-3 blocked MCF-7 cell invasion by inducing a reversal of EMT. • Wnt/β-catenin signaling is involved in MR-3-induced EMT

3,5,4′-Trimethoxystilbene, a natural methoxylated analog of resveratrol, inhibits breast cancer cell invasiveness by downregulation of PI3K/Akt and Wnt/β-catenin signaling cascades and reversal of epithelial–mesenchymal transition

Energy Technology Data Exchange (ETDEWEB)

Tsai, Jie-Heng [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Hsu, Li-Sung [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Clinical Laboratory, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Lin, Chih-Li [Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Hong, Hui-Mei [Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Pan, Min-Hsiung [Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan, ROC (China); Way, Tzong-Der [Department of Biological Science and Technology, College of Life Sciences, China Medical University, Taichung 40402, Taiwan, ROC (China); Chen, Wei-Jen, E-mail: cwj519@csmu.edu.tw [Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China)

2013-11-01

The molecular basis of epithelial–mesenchymal transition (EMT) functions as a potential therapeutic target for breast cancer because EMT may endow breast tumor-initiating cells with stem-like characteristics and enable the dissemination of breast cancer cells. We have recently verified the antitumor activity of 3,5,4′-trimethoxystilbene (MR-3), a naturally methoxylated derivative of resveratrol, in colorectal cancer xenografts via an induction of apoptosis. The effect of MR-3 on EMT and the invasiveness of human MCF-7 breast adenocarcinoma cell line were also explored. We found that MR-3 significantly increased epithelial marker E-cadherin expression and triggered a cobblestone-like morphology of MCF-7 cells, while reciprocally decreasing the expression of mesenchymal markers, such as snail, slug, and vimentin. In parallel with EMT reversal, MR-3 downregulated the invasion and migration of MCF-7 cells. Exploring the action mechanism of MR-3 on the suppression of EMT and invasion indicates that MR-3 markedly reduced the expression and nuclear translocation of β-catenin, accompanied with the downregulation of β-catenin target genes and the increment of membrane-bound β-catenin. These results suggest the involvement of Wnt/β-catenin signaling in the MR-3-induced EMT reversion of MCF-7 cells. Notably, MR-3 restored glycogen synthase kinase-3β activity by inhibiting the phosphorylation of Akt, the event required for β-catenin destruction via a proteasome-mediated system. Overall, these findings indicate that the anti-invasive activity of MR-3 on MCF-7 cells may result from the suppression of EMT via down-regulating phosphatidylinositol 3-kinase (PI3K)/AKT signaling, and consequently, β-catenin nuclear translocation. These occurrences ultimately lead to the blockage of EMT and the invasion of breast cancer cells. - Highlights: • MR-3 blocked MCF-7 cell invasion by inducing a reversal of EMT. • Wnt/β-catenin signaling is involved in MR-3-induced EMT

Effect of beta-carotene-rich tomato lycopene beta-cyclase ( tlcy-b) on cell growth inhibition in HT-29 colon adenocarcinoma cells.

Science.gov (United States)

Palozza, Paola; Bellovino, Diana; Simone, Rossella; Boninsegna, Alma; Cellini, Francesco; Monastra, Giovanni; Gaetani, Sancia

2009-07-01

Lycopene beta-cyclase (tlcy-b) tomatoes, obtained by modulating carotenogenesis via genetic engineering, contain a large amount of beta-carotene, as clearly visible by their intense orange colour. In the present study we have subjected tlcy-b tomatoes to an in vitro simulated digestion and analysed the effects of digestate on cell proliferation. To this aim we used HT-29 human colon adenocarcinoma cells, grown in monolayers, as a model. Digested tomatoes were diluted (20 ml, 50 ml and 100 ml/l) in culture medium and added to the cells for different incubation times (24 h, 48 h and 72 h). Inhibition of cell growth by tomato digestate was dose-dependent and resulted from an arrest of cell cycle progression at the G0/G1 and G2/M phase and by apoptosis induction. A down-regulation of cyclin D1, Bcl-2 and Bcl-xl expression was observed. We also found that heat treatment of samples before digestion enhanced beta-carotene release and therefore cell growth inhibition. To induce with purified beta-carotene solubilised in tetrahydrofuran the same cell growth inhibition obtained with the tomato digestate, a higher amount of the carotenoid was necessary, suggesting that beta-carotene micellarised during digestion is utilised more efficiently by the cells, but also that other tomato molecules, reasonably made available during digestion, may be present and cooperate with beta-carotene in promoting cell growth arrest.

The inflammatory mediator leukotriene D4 induces subcellular β-catenin translocation and migration of colon cancer cells

International Nuclear Information System (INIS)

Salim, Tavga; Sand-Dejmek, Janna; Sjölander, Anita

2014-01-01

The abnormal activation of the Wnt/β-catenin pathway frequently occurs in colorectal cancer. The nuclear translocation of β-catenin activates the transcription of target genes that promote cell proliferation, survival, and invasion. The pro-inflammatory mediator leukotriene D 4 (LTD 4 ) exerts its effects through the CysLT 1 receptor. We previously reported an upregulation of CysLT 1 R in patients with colon cancer, suggesting the importance of leukotrienes in colon cancer. The aim of this study was to investigate the impact of LTD 4 on Wnt/β-catenin signaling and its effects on proliferation and migration of colon cancer cells. LTD 4 stimulation led to an increase in β-catenin expression, β-catenin nuclear translocation and the subsequent transcription of MYC and CCND1. Furthermore, LTD 4 significantly reduced the expression of E-cadherin and β-catenin at the plasma membrane and increased the migration and proliferation of HCT116 colon cancer cells. The effects of LTD 4 can be blocked by the inhibition of CysLT 1 R. Furthermore, LTD 4 induced the inhibition of glycogen synthase kinase 3 (GSK)-3β activity, indicating a crosstalk between the G-protein-coupled receptor CysLT 1 and the Wnt/β-catenin pathway. In conclusion, LTD 4 , which can be secreted from macrophages and leukocytes in the tumor microenvironment, induces β-catenin translocation and the activation of β-catenin target genes, resulting in the increased proliferation and migration of colon cancer cells. - Highlights: • Leukotriene D 4 (LTD 4 ) lowers membrane β-catenin but increases nuclear β-catenin levels in colon cancer cells. • In agreement, LTD 4 triggers inactivation of GSK-3β, activation of TCF/LEF and increased expression of Cyclin D1 and c-Myc. • LTD 4 also caused a significant reduction in the expression of E-cadherin and an increased migration of colon cancer cells

Modulation of Beta-catenin activity with PKD1 in Prostate Cancer

Science.gov (United States)

2010-04-01

which further suggests that PKD1 plays a major role in membrane transport of β-catenin. We have previously published that down regulation of PKD1 in...result allow cells to undergo cell death. In addition, these self- assemblies may also overcome membrane associated efflux transporter protein and drug... dendrimers , Adv Drug Deliv Rev, 57 (2005) 2238-2270. [41] O. M. Koo, I. Rubinstein and H. Onyuksel, Role of nanotechnology in targeted drug delivery and

Down-regulation of LRP1B in colon cancer promoted the growth and migration of cancer cells.

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Wang, Zhiqiang; Sun, Peng; Gao, Chun; Chen, Ji; Li, Jun; Chen, Zhonghao; Xu, Ming; Shao, Jun; Zhang, Yunpeng; Xie, Jiang

2017-08-01

Aberrant activation of beta-catenin/TCF signaling is one of the hallmarks of colon cancer. It is of great interest to study the mechanism for the regulation of beta-catenin/TCF signaling. In this study, it was found that LRP1B was down-regulated in colon cancer tissues and inhibited the growth, migration and metastasis of colon cancer cells. The molecular mechanism study revealed that LRP1B interacted with DVL2, inhibited the interaction between DVL2 and Axin, and negatively regulated beta-catenin/TCF signaling. Taken together, our study demonstrated the suppressive roles of LRP1B in the progression of colon cancer, implicating that restoring the function of LRP1B would be a promising strategy for the treatment of colon cancer. Copyright © 2017. Published by Elsevier Inc.

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

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Yao, Yingjia [School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600 (China); Gao, Zhong [Department of Interventional Therapy, Dalian Municipal Central Hospital, Dalian 116033 (China); Liang, Wenbo [Medical College of Dalian University, Dalian 116600, Liaoning (China); Kong, Liang; Jiao, Yanan; Li, Shaoheng; Tao, Zhenyu; Yan, Yuhui [School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600 (China); Yang, Jingxian, E-mail: jingxianyang@yahoo.com [School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600 (China)

2015-12-15

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ{sub 1–42} peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

International Nuclear Information System (INIS)

Yao, Yingjia; Gao, Zhong; Liang, Wenbo; Kong, Liang; Jiao, Yanan; Li, Shaoheng; Tao, Zhenyu; Yan, Yuhui; Yang, Jingxian

2015-01-01

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ 1–42 peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

Spatio-temporal Model of Endogenous ROS and Raft-Dependent WNT/Beta-Catenin Signaling Driving Cell Fate Commitment in Human Neural Progenitor Cells

Science.gov (United States)

Haack, Fiete; Lemcke, Heiko; Ewald, Roland; Rharass, Tareck; Uhrmacher, Adelinde M.

2015-01-01

Canonical WNT/β-catenin signaling is a central pathway in embryonic development, but it is also connected to a number of cancers and developmental disorders. Here we apply a combined in-vitro and in-silico approach to investigate the spatio-temporal regulation of WNT/β-catenin signaling during the early neural differentiation process of human neural progenitors cells (hNPCs), which form a new prospect for replacement therapies in the context of neurodegenerative diseases. Experimental measurements indicate a second signal mechanism, in addition to canonical WNT signaling, being involved in the regulation of nuclear β-catenin levels during the cell fate commitment phase of neural differentiation. We find that the biphasic activation of β-catenin signaling observed experimentally can only be explained through a model that combines Reactive Oxygen Species (ROS) and raft dependent WNT/β-catenin signaling. Accordingly after initiation of differentiation endogenous ROS activates DVL in a redox-dependent manner leading to a transient activation of down-stream β-catenin signaling, followed by continuous auto/paracrine WNT signaling, which crucially depends on lipid rafts. Our simulation studies further illustrate the elaborate spatio-temporal regulation of DVL, which, depending on its concentration and localization, may either act as direct inducer of the transient ROS/β-catenin signal or as amplifier during continuous auto-/parcrine WNT/β-catenin signaling. In addition we provide the first stochastic computational model of WNT/β-catenin signaling that combines membrane-related and intracellular processes, including lipid rafts/receptor dynamics as well as WNT- and ROS-dependent β-catenin activation. The model’s predictive ability is demonstrated under a wide range of varying conditions for in-vitro and in-silico reference data sets. Our in-silico approach is realized in a multi-level rule-based language, that facilitates the extension and modification of the

N-cadherin in adult rat cardiomyocytes in culture. II. Spatio-temporal appearance of proteins involved in cell-cell contact and communication. Formation of two distinct N-cadherin/catenin complexes.

Science.gov (United States)

Hertig, C M; Butz, S; Koch, S; Eppenberger-Eberhardt, M; Kemler, R; Eppenberger, H M

1996-01-01

The spatio-temporal appearance and distribution of proteins forming the intercalated disc were investigated in adult rat cardiomyocytes (ARC). The 'redifferentiation model' of ARC involves extensive remodelling of the plasma membrane and of the myofibrillar apparatus. It represents a valuable system to elucidate the formation of cell-cell contact between cardiomyocytes and to assess the mechanisms by which different proteins involved in the cell-cell adhesion process are sorted in a precise manner to the sites of function. Appearance of N-cadherin, the catenins and connexin43 within newly formed adherens and gap junctions was studied. Here first evidence is provided for a formation of two distinct and separable N-cadherin/catenin complexes in cardiomyocytes. Both complexes are composed of N-cadherin and alpha-catenin which bind to either beta-catenin or plakoglobin in a mutually exclusive manner. The two N-cadherin/catenin complexes are assumed to be functionally involved in the formation of cell-cell contacts in ARC; however, the differential appearance and localization of the two types of complexes may also point to a specific role during ARC differentiation. The newly synthesized beta-catenin containing complex is more abundant during the first stages in culture after ARC isolation, while the newly synthesized plakoglobin containing complex progressively accumulates during the morphological changes of ARC. ARC formed a tissue-like pattern in culture whereby the new cell-cell contacts could be dissolved through Ca2+ depletion. Presence of cAMP and replenishment of Ca2+ content in the culture medium not only allowed reformation of cell-cell contacts but also affected the relative protein ratio between the two N-cadherin/catenin complexes, increasing the relative amount of newly synthesized beta-catenin over plakoglobin at a particular stage of ARC differentiation. The clustered N-cadherin/catenin complexes at the plasma membrane appear to be a prerequisite for the

α-Catenin localization and sarcomere self-organization on N-cadherin adhesive patterns are myocyte contractility driven.

Directory of Open Access Journals (Sweden)

Anant Chopra

Full Text Available The N-cadherin (N-cad complex plays a crucial role in cardiac cell structure and function. Cadherins are adhesion proteins linking adjacent cardiac cells and, like integrin adhesions, are sensitive to force transmission. Forces through these adhesions are capable of eliciting structural and functional changes in myocytes. Compared to integrins, the mechanisms of force transduction through cadherins are less explored. α-catenin is a major component of the cadherin-catenin complex, thought to provide a link to the cell actin cytoskeleton. Using N-cad micropatterned substrates in an adhesion constrainment model, the results from this study show that α-catenin localizes to regions of highest internal stress in myocytes. This localization suggests that α-catenin acts as an adaptor protein associated with the cadherin mechanosensory apparatus, which is distinct from mechanosensing through integrins. Myosin inhibition in cells bound by integrins to fibronectin-coated patterns disrupts myofibiril organization, whereas on N-cad coated patterns, myosin inhibition leads to better organized myofibrils. This result indicates that the two adhesion systems provide independent mechanisms for regulating myocyte structural organization.

WNT2B2 mRNA, up-regulated in primary gastric cancer, is a positive regulator of the WNT- beta-catenin-TCF signaling pathway.

Science.gov (United States)

Katoh, M; Kirikoshi, H; Terasaki, H; Shiokawa, K

2001-12-21

Genetic alterations of WNT signaling molecules lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway. We have previously cloned and characterized WNT2B/WNT13 gene on human chromosome 1p13, which is homologous to proto-oncogene WNT2 on human chromosome 7q31. WNT2B1 and WNT2B2 mRNAs, generated from the WNT2B gene due to alternative splicing of the alternative promoter type, encode almost identical polypeptides with divergence in the N-terminal region. WNT2B2 mRNA rather than WNT2B1 mRNA is preferentially expressed in NT2 cells with the potential of neuronal differentiation. Here, we describe our investigations of expression of WNT2B mRNAs in various types of human primary cancer. Matched tumor/normal expression array analysis revealed that WNT2B mRNAs were significantly up-regulated in 2 of 8 cases of primary gastric cancer. WNT2B2 mRNA rather than WNT2B1 mRNA was found to be preferentially up-regulated in a case of primary gastric cancer (signet ring cell carcinoma). Function of WNT2B1 mRNA and that of WNT2B2 mRNA were investigated by using Xenopus axis duplication assay. Injection of synthetic WNT2B1 mRNA into the ventral marginal zone of fertilized Xenopus eggs at the 4-cell stage did not induce axis duplication. In contrast, ventral injection of synthetic WNT2B2 mRNA induced axis duplication in 90% of embryos (complete axis duplication, 24%). These results strongly suggest that WNT2B2 up-regulation in some cases of gastric cancer might lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway.

JS-K, a nitric oxide-releasing prodrug, modulates ß-catenin/TCF signaling in leukemic Jurkat cells: evidence of an S-nitrosylated mechanism.

Science.gov (United States)

Nath, Niharika; Chattopadhyay, Mitali; Pospishil, Liliya; Cieciura, Lucyna Z; Goswami, Satindra; Kodela, Ravinder; Saavedra, Joseph E; Keefer, Larry K; Kashfi, Khosrow

2010-12-01

β-Catenin is a central player of the Wnt signaling pathway that regulates cell-cell adhesion and may promote leukemia cell proliferation. We examined whether JS-K, an NO-donating prodrug, modulates the Wnt/β-catenin/TCF-4 signaling pathway in Jurkat T-Acute Lymphoblastic Leukemia cells. JS-K inhibited Jurkat T cell growth in a concentration and time-dependent manner. The IC(50)s for cell growth inhibition were 14±0.7 and 9±1.2μM at 24 and 48h, respectively. Treatment of the cells with JS-K for 24h, caused a dose-dependent increase in apoptosis from 16±3.3% at 10μM to 74.8±2% at 100μM and a decrease in proliferation. This growth inhibition was also due, in part, to alterations in the different phases of the cell cycle. JS-K exhibited a dose-dependent cytotoxicity as measured by LDH release at 24h. However, between 2 and 8h, LDH release was less than 20% for any indicated JS-K concentration. The β-catenin/TCF-4 transcriptional inhibitory activity was reduced by 32±8, 63±5, and 93±2% at 2, 10, and 25μM JS-K, respectively, based on luciferase reporter assays. JS-K reduced nuclear β-catenin and cyclin D1 protein levels, but cytosolic β-catenin expression did not change. Based on a time-course assay of S-nitrosylation of proteins by a biotin switch assay, S-nitrsolyation of nuclear β-catenin was determined to precede its degradation. A comparison of the S-nitrosylated nuclear β-catenin to the total nuclear β-catenin showed that β-catenin protein levels were degraded at 24h, while S-nitrosylation of β-catenin occurred earlier at 0-6h. The NO scavenger PTIO abrogated the JS-K mediated degradation of β-catenin demonstrating the need for NO. Copyright © 2010 Elsevier Inc. All rights reserved.

Beta-catenin accelerates human papilloma virus type-16 mediated cervical carcinogenesis in transgenic mice.

Directory of Open Access Journals (Sweden)

Gülay Bulut

Full Text Available Human papilloma virus (HPV is the principal etiological agent of cervical cancer in women, and its DNA is present in virtually all of these tumors. However, exposure to the high-risk HPV types alone is insufficient for tumor development. Identifying specific collaborating factors that will lead to cervical cancer remains an unanswered question, especially because millions of women are exposed to HPV. Our earlier work using an in vitro model indicated that activation of the canonical Wnt pathway in HPV-positive epithelial cells was sufficient to induce anchorage independent growth. We therefore hypothesized that constitutive activation of this pathway might function as the "second hit." To address this possibility, we developed two double-transgenic (DT mouse models, K14-E7/ΔN87βcat and K14-HPV16/ΔN87βcat that express either the proteins encoded by the E7 oncogene or the HPV16 early region along with constitutively active β-catenin, which was expressed by linking it to the keratin-14 (K14 promoter. We initiated tumor formation by treating all groups with estrogen for six months. Invasive cervical cancer was observed in 11% of the K14-ΔN87βcat mice, expressing activated β-catenin and in 50% of the animals expressing the HPV16 E7 oncogene. In double-transgenic mice, coexpression of β-catenin and HPV16 E7 induced invasive cervical cancer at about 7 months in 94% of the cases. We did not observe cervical cancer in any group unless the mice were treated with estrogen. In the second model, K14-HPV16 mice suffered cervical dysplasias, but this phenotype was not augmented in HPV16/ΔN87βcat mice. In summary, the phenotypes of the K14-E7/ΔN87βcat mice support the hypothesis that activation of the Wnt/β-catenin pathway in HPV-associated premalignant lesions plays a functional role in accelerating cervical carcinogenesis.

Turning over renal osteodystrophy dogma: direct actions of FGF23 on osteoblast β-catenin pathway.

Science.gov (United States)

Schiavi, Susan C; Moysés, Rosa M A

2016-07-01

Although recognized as a major complication of chronic kidney disease (CKD), the pathophysiology of the CKD-related mineral and bone disorder (CKD-MBD) is not completely understood. Recently, the inhibition of Wnt/β-catenin pathway in osteocytes by sclerostin has been shown to play a role in CKD-MBD. The study by Carrilo-Lopez et al. confirms this inhibition in an experimental model of CKD. Moreover, they describe direct actions of FGF23-Klotho on osteoblasts, increasing the expression of DKK1, another Wnt/β-catenin pathway inhibitor. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Quantitative Phosphoproteomic Study Reveals that Protein Kinase A Regulates Neural Stem Cell Differentiation Through Phosphorylation of Catenin Beta-1 and Glycogen Synthase Kinase 3β.

Science.gov (United States)

Wang, Shuxin; Li, Zheyi; Shen, Hongyan; Zhang, Zhong; Yin, Yuxin; Wang, Qingsong; Zhao, Xuyang; Ji, Jianguo

2016-08-01

Protein phosphorylation is central to the understanding of multiple cellular signaling pathways responsible for regulating the self-renewal and differentiation of neural stem cells (NSCs). Here we performed a large-scale phosphoproteomic analysis of rat fetal NSCs using strong cation exchange chromatography prefractionation and citric acid-assisted two-step enrichment with TiO2 strategy followed by nanoLC-MS/MS analysis. Totally we identified 32,546 phosphosites on 5,091 phosphoproteins, among which 23,945 were class I phosphosites, and quantified 16,000 sites during NSC differentiation. More than 65% of class I phosphosites were novel when compared with PhosphoSitePlus database. Quantification results showed that the early and late stage of NSC differentiation differ greatly. We mapped 69 changed phosphosites on 20 proteins involved in Wnt signaling pathway, including S552 on catenin beta-1 (Ctnnb1) and S9 on glycogen synthase kinase 3β (Gsk3β). Western blotting and real-time PCR results proved that Wnt signaling pathway plays critical roles in NSC fate determination. Furthermore, inhibition and activation of PKA dramatically affected the phosphorylation state of Ctnnb1 and Gsk3β, which regulates the differentiation of NSCs. Our data provides a valuable resource for studying the self-renewal and differentiation of NSCs. Stem Cells 2016;34:2090-2101. © 2016 AlphaMed Press.

Inhibition of. beta. -bungarotoxin binding to brain membranes by mast cell degranulating peptide, toxin I, and ethylene glycol bis(. beta. -aminoethyl ether)-N,N,N',N'-tetraacetic acid

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R.R.; Betz, H.; Rehm, H.

1988-02-09

The presynaptically active snake venom neurotoxin ..beta..-bungarotoxin (..beta..-Butx) is known to affect neurotransmitter release by binding to a subtype of voltage-activated K/sup +/ channels. Here the authors show that mast cell degranulating (MCD) peptide from bee venom inhibits the binding of /sup 125/I-labeled ..beta..-Butx to chick and rat brain membranes with apparent K/sub i/ values of 180 nM and 1100 nM, respectively. The mechanisms of inhibition of MCD peptide is noncompetitive, as is inhibition of /sup 125/I-..beta..-Butx binding by the protease inhibitor homologue from mamba venom, toxin I. ..beta..-Butx and its binding antagonists thus bind to different sites of the same membrane protein. Removal of Ca/sup 2 +/ by ethylene glycol bis(..beta..-aminoethyl ether)-N,N,N',N'-tetraacetic acid inhibits the binding of /sup 125/I-..beta..-Butx by lowering its affinity to brain membranes.

Wnt/β-catenin pathway involvement in ionizing radiation-induced invasion of U87 glioblastoma cells

Energy Technology Data Exchange (ETDEWEB)

Dong, Zhen [Huazhong University of Science and Technology, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Wuhan (China); Zhou, Lin [Huazhong University of Science and Technology, Department of Histoembryology, Tongji Medical College, Wuhan (China); Han, Na; Zhang, Mengxian [Huazhong University of Science and Technology, Department of Oncology, Tongji Hospital, Tongji Medical College, Wuhan (China); Lyu, Xiaojuan [Huazhong University of Science and Technology, Department of Oncology, The Central Hospital of Wuhan, Tongji Medical College, Wuhan (China)

2015-08-15

Radiotherapy has been reported to promote the invasion of glioblastoma cells; however, the underlying mechanisms remain unclear. Here, we investigated the role of the Wnt/β-catenin pathway in radiation-induced invasion of glioblastoma cells. U87 cells were irradiated with 3 Gy or sham irradiated in the presence or absence of the Wnt/β-catenin pathway inhibitor XAV 939. Cell invasion was determined by an xCELLigence real-time cell analyser and matrigel invasion assays. The intracellular distribution of β-catenin in U87 cells with or without irradiation was examined by immunofluorescence and Western blotting of nuclear fractions. We next investigated the effect of irradiation on Wnt/β-catenin pathway activity using TOP/FOP flash luciferase assays and quantitative polymerase chain reaction analysis of β-catenin target genes. The expression levels and activities of two target genes, matrix metalloproteinase (MMP)-2 and MMP-9, were examined further by Western blotting and zymography. U87 cell invasiveness was increased significantly by ionizing radiation. Interestingly, ionizing radiation induced nuclear translocation and accumulation of β-catenin. Moreover, we found increased β-catenin/TCF transcriptional activities, followed by up-regulation of downstream genes in the Wnt/β-catenin pathway in irradiated U87 cells. Importantly, inhibition of the Wnt/β-catenin pathway by XAV 939, which promotes degradation of β-catenin, significantly abrogated the pro-invasion effects of irradiation. Mechanistically, XAV 939 suppressed ionizing radiation-triggered up-regulation of MMP-2 and MMP-9, and inhibited the activities of these gelatinases. Our data demonstrate a pivotal role of the Wnt/β-catenin pathway in ionizing radiation-induced invasion of glioblastoma cells, and suggest that targeting β-catenin is a promising therapeutic approach to overcoming glioma radioresistance. (orig.) [German] Studien haben gezeigt, dass eine Strahlentherapie die Invasivitaet von

The inflammatory mediator leukotriene D{sub 4} induces subcellular β-catenin translocation and migration of colon cancer cells

Energy Technology Data Exchange (ETDEWEB)

Salim, Tavga [Division of Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Clinical Research Center, Skåne University Hospital, Malmö (Sweden); Sand-Dejmek, Janna [Division of Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Clinical Research Center, Skåne University Hospital, Malmö (Sweden); Section of Surgery, Department of Clinical Sciences, Lund University, Skåne University Hospital, Malmö (Sweden); Bayer HealthCare, Pharmaceuticals Medical Affairs, Solna (Sweden); Sjölander, Anita, E-mail: anita.sjolander@med.lu.se [Division of Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Clinical Research Center, Skåne University Hospital, Malmö (Sweden)

2014-02-15

The abnormal activation of the Wnt/β-catenin pathway frequently occurs in colorectal cancer. The nuclear translocation of β-catenin activates the transcription of target genes that promote cell proliferation, survival, and invasion. The pro-inflammatory mediator leukotriene D{sub 4} (LTD{sub 4}) exerts its effects through the CysLT{sub 1} receptor. We previously reported an upregulation of CysLT{sub 1}R in patients with colon cancer, suggesting the importance of leukotrienes in colon cancer. The aim of this study was to investigate the impact of LTD{sub 4} on Wnt/β-catenin signaling and its effects on proliferation and migration of colon cancer cells. LTD{sub 4} stimulation led to an increase in β-catenin expression, β-catenin nuclear translocation and the subsequent transcription of MYC and CCND1. Furthermore, LTD{sub 4} significantly reduced the expression of E-cadherin and β-catenin at the plasma membrane and increased the migration and proliferation of HCT116 colon cancer cells. The effects of LTD{sub 4} can be blocked by the inhibition of CysLT{sub 1}R. Furthermore, LTD{sub 4} induced the inhibition of glycogen synthase kinase 3 (GSK)-3β activity, indicating a crosstalk between the G-protein-coupled receptor CysLT{sub 1} and the Wnt/β-catenin pathway. In conclusion, LTD{sub 4}, which can be secreted from macrophages and leukocytes in the tumor microenvironment, induces β-catenin translocation and the activation of β-catenin target genes, resulting in the increased proliferation and migration of colon cancer cells. - Highlights: • Leukotriene D{sub 4} (LTD{sub 4}) lowers membrane β-catenin but increases nuclear β-catenin levels in colon cancer cells. • In agreement, LTD{sub 4} triggers inactivation of GSK-3β, activation of TCF/LEF and increased expression of Cyclin D1 and c-Myc. • LTD{sub 4} also caused a significant reduction in the expression of E-cadherin and an increased migration of colon cancer cells.

Osteopontin induces β-catenin signaling through activation of Akt in prostate cancer cells

International Nuclear Information System (INIS)

Robertson, Brian W.; Chellaiah, Meenakshi A.

2010-01-01

Secretion of osteopontin (OPN) by cancer cells is a known mediator of tumorigenesis and cancer progression in both experimental and clinical studies. Our work demonstrates that OPN can activate Akt, an important step in cancer progression. Both ILK and PI3K are integral proteins in the OPN/Akt pathway, as inhibition of either kinase leads to a loss of OPN-mediated Akt activation. Subsequent to OPN-induced Akt activation, we observe inactivation of GSK-3β, a regulator of β-catenin. Osteopontin stimulation leads to an overall increase in β-catenin protein levels with a resultant transfer of β-catenin to the nucleus. Through the nuclear import of β-catenin, OPN increases both the transcription and protein levels of MMP-7 and CD44, which are known TCF/LEF transcription targets. This work describes an important aspect of cancer progression induced by OPN.

HuR represses Wnt/β-catenin-mediated transcriptional activity by promoting cytoplasmic localization of β-catenin

Energy Technology Data Exchange (ETDEWEB)

Kim, Inae; Hur, Jung; Jeong, Sunjoo, E-mail: sjsj@dankook.ac.kr

2015-01-30

Highlights: • Wnt signaling as well as β-catenin overexpression enhance HuR cytoplasmic export. • HuR overexpression promotes cytoplasmic localization of β-catenin from the perinuclear fraction. • Wnt/β-catenin-mediated transcriptional activity is repressesed by HuR. - Abstract: β-Catenin is the key transcriptional activator of canonical Wnt signaling in the nucleus; thus, nuclear accumulation of β-catenin is a critical step for expressing target genes. β-Catenin accumulates in the nucleus of cancer cells where it activates oncogenic target genes. Hu antigen R (HuR) is a RNA binding protein that regulates multiple post-transcriptional processes including RNA stability. Thus, cytoplasmic HuR protein may be involved in tumorigenesis by stabilizing oncogenic transcripts, but the molecular mechanism remains unclear. Here, we observed that Wnt/β-catenin signaling induced export of the HuR protein, whereas HuR overexpression promoted accumulation of the β-catenin protein in the cytoplasm. Thus, Wnt/β-catenin-mediated transcriptional activity in the nucleus was reduced by overexpressing HuR. These results suggest novel and uncharacterized cytoplasmic β-catenin functions related to HuR-mediated RNA metabolism in cancer cells.

HuR represses Wnt/β-catenin-mediated transcriptional activity by promoting cytoplasmic localization of β-catenin

International Nuclear Information System (INIS)

Kim, Inae; Hur, Jung; Jeong, Sunjoo

2015-01-01

Highlights: • Wnt signaling as well as β-catenin overexpression enhance HuR cytoplasmic export. • HuR overexpression promotes cytoplasmic localization of β-catenin from the perinuclear fraction. • Wnt/β-catenin-mediated transcriptional activity is repressesed by HuR. - Abstract: β-Catenin is the key transcriptional activator of canonical Wnt signaling in the nucleus; thus, nuclear accumulation of β-catenin is a critical step for expressing target genes. β-Catenin accumulates in the nucleus of cancer cells where it activates oncogenic target genes. Hu antigen R (HuR) is a RNA binding protein that regulates multiple post-transcriptional processes including RNA stability. Thus, cytoplasmic HuR protein may be involved in tumorigenesis by stabilizing oncogenic transcripts, but the molecular mechanism remains unclear. Here, we observed that Wnt/β-catenin signaling induced export of the HuR protein, whereas HuR overexpression promoted accumulation of the β-catenin protein in the cytoplasm. Thus, Wnt/β-catenin-mediated transcriptional activity in the nucleus was reduced by overexpressing HuR. These results suggest novel and uncharacterized cytoplasmic β-catenin functions related to HuR-mediated RNA metabolism in cancer cells

Mangiferin exerts antitumor activity in breast cancer cells by regulating matrix metalloproteinases, epithelial to mesenchymal transition, and β-catenin signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Li, Hongzhong; Huang, Jing; Yang, Bing; Xiang, Tingxiu; Yin, Xuedong; Peng, Weiyan; Cheng, Wei [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Wan, Jingyuan; Luo, Fuling [Department of Pharmacology, Chongqing Medical University, Chongqing (China); Li, Hongyuan [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Ren, Guosheng, E-mail: rgs726@163.com [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China)

2013-10-01

Although mangiferin which is a naturally occurring glucosylxanthone has exhibited promising anticancer activities, the detailed molecular mechanism of mangiferin on cancers still remains enigmatic. In this study, the anticancer activity of mangiferin was evaluated in breast cancer cell line-based in vitro and in vivo models. We showed that mangiferin treatment resulted in decreased cell viability and suppression of metastatic potential in breast cancer cells. Further mechanistic investigation revealed that mangiferin induced decreased matrix metalloproteinase (MMP)-7 and -9, and reversal of epithelial–mesenchymal transition (EMT). Moreover, it was demonstrated that mangiferin significantly inhibited the activation of β-catenin pathway. Subsequent experiments showed that inhibiting β-catenin pathway might play a central role in mangiferin-induced anticancer activity through modulation of MMP-7 and -9, and EMT. Consistent with these findings in vitro, the antitumor potential was also verified in mangiferin-treated MDA-MB-231 xenograft mice where significantly decreased tumor volume, weight and proliferation, and increased apoptosis were obtained, with lower expression of MMP-7 and -9, vimentin and active β-catenin, and higher expression of E-cadherin. Taken together, our study suggests that mangiferin might be used as an effective chemopreventive agent against breast cancer. - Highlights: • Mangiferin inhibits growth and metastatic potential in breast cancer cells. • Mangiferin down-regulates MMP-7 and -9 in breast cancer cells. • Mangiferin induces the reversal of EMT in metastatic breast cancer cells. • Mangiferin inhibits the activation of β-catenin pathway in breast cancer cells. • Inhibiting β-catenin is responsible for the antitumor activity of mangiferin.

Andrographolide suppresses melanin synthesis through Akt/GSK3β/β-catenin signal pathway.

Science.gov (United States)

Zhu, Ping-Ya; Yin, Wei-Han; Wang, Meng-Ran; Dang, Yong-Yan; Ye, Xi-Yun

2015-07-01

Tyrosinase (TYR) is the key enzyme controlling the production of melanin. Very few papers have reported that andrographolide can inhibit melanin content. To investigate the effects of andrographolide on melanin synthesis. Cell viability, melanin content, TYR activity, transcriptional and protein expression levels of TYR family and other kinds of proteins involved in melanogenesis were measured after the treatments of andrographolide. It was found that andrographolide decreased melanin content, TYR activity and transcriptional and protein expression of TYR family and microphthalmia-associated transcription factor (MITF) in B16F10 melanoma cells. Data showed andrographolide also decreased melanin content and TYR content in ultraviolet B (UVB) irradiation induced brown guinea pigs. Moreover, we found that melanin content and TYR activity were effectively inhibited in Human Epidermis Melanocyte (HEM) treated with andrographolide at the medium concentrations without apparent effect on cell viability. Results in experiments treated with MG-132 or cycloheximide (CHX) showed that andrographolide lowered the content of β-catenin in cell nucleus resulting from accelerating the degradation of β-catenin. Phosphorylation of glycogen synthase kinase 3β (GSK3β) and Akt decreased simultaneously. 6-Bromoindirubin-3'-oxime (BIO, inhibitor of GSK3β) and insulin-like growth factors-1 (IGF-1, activator of Akt) could reverse the decline of β-catenin in B16F10 cells induced by andrographolide. These results demonstrate that andrographolide can effectively suppress melanin content and TYR activity in B16F10 cells, HEM cells and UVB-induced brown guinea pig skin by decreasing phosphorylation of GSK3β dependent on Akt, promoting the degradation of β-catenin, inhibiting β-catenin into the nucleus and decreasing the expression of MITF and TYR family. Data indicate that andrographolide may be a potential whiting agent which can have great market in cosmetics and in clinical such as

TUSC3 induces autophagy in human non-small cell lung cancer cells through Wnt/β-catenin signaling.

Science.gov (United States)

Peng, Yun; Cao, Jun; Yao, Xiao-Yi; Wang, Jian-Xin; Zhong, Mei-Zuo; Gan, Ping-Ping; Li, Jian-Huang

2017-08-08

We investigated the effects of tumor suppressor candidate 3 ( TUSC3 ) on autophagy in human non-small cell lung cancer (NSCLC) cells. A total of 118 NSCLC patients (88 males and 30 females) who underwent surgery at our institute were enrolled in the study. Immunohistochemical analysis revealed that TUSC3 protein expression was lower in NSCLC specimens than adjacent normal tissue. Correspondingly, there was greater methylation of TUSC3 in NSCLC than adjacent normal tissue. After transient transfection of A549 NSCLC cells with constructs designed to up-regulate or down-regulate TUSC3 expression, we analyzed the effects of inhibiting the Wnt pathway (XAV939) and autophagy (chloroquine, CQ) on the behavior of NSCLC cells. We also performed TOP/FOP-Flash reporter assays, MTT assays, Annexin V-FITC/propidium iodide staining, and acridine orange staining to evaluate Wnt/β-catenin signaling, cell proliferation, apoptosis, and autophagy, respectively. Expression of Wnt/β-catenin pathway components and autophagy-related proteins was analyzed using qRT-PCR and Western blotting. We found that TUSC3 inhibited cell proliferation and promoted both apoptosis and autophagy in A549 cells. In addition, TUSC3 increased expression of autophagy-related proteins. It also increased expression of Wnt/β-catenin signaling pathway components and promoted nuclear transfer of β-catenin, resulting in activation of Wnt/β-catenin signaling. TUSC3 thus induces autophagy in human NSCLC cells through activation of the Wnt/β-catenin signaling pathway.

Role of β-catenin signaling in the anti-invasive effect of the omega-3 fatty acid DHA in human melanoma cells.

Science.gov (United States)

Serini, Simona; Zinzi, Antonio; Ottes Vasconcelos, Renata; Fasano, Elena; Riillo, Maria Greca; Celleno, Leonardo; Trombino, Sonia; Cassano, Roberta; Calviello, Gabriella

2016-11-01

We previously found that docosahexaenoic acid (DHA), a dietary polyunsaturated fatty acid present at high level in fatty fish, inhibited cell growth and induced differentiation of melanoma cells in vitro by increasing nuclear β-catenin content. An anti-neoplastic role of nuclear β-catenin was suggested in melanoma, and related to the presence in the melanocyte lineage of the microphtalmia transcription factor (MITF), which interferes with the transcription of β-catenin/TCF/LEF pro-invasive target genes. In the present work we investigated if DHA could inhibit the invasive potential of melanoma cells, and if this effect could be related to DHA-induced alterations of the Wnt/β-catenin signaling, including changes in MITF expression. WM115 and WM266-4 human melanoma, and B16-F10 murine melanoma cell lines were used. Cell invasion was evaluated by Wound Healing and Matrigel transwell assays. Protein expression was analyzed by Western Blotting and β-catenin phosphorylation by immunoprecipitation. The role of MITF in the anti-invasive effect of DHA was analyzed by siRNA gene silencing. We found that DHA inhibited anchorage-independent cell growth, reduced their migration/invasion in vitro and down-regulated several Matrix Metalloproteinases (MMP: MMP-2, MT1-MMP and MMP-13), known to be involved in melanoma invasion. We related these effects to the β-catenin increased nuclear expression and PKA-dependent phosphorylation, as well as to the increased expression of MITF. The data obtained further support the potential role of dietary DHA as suppressor of melanoma progression to invasive malignancy through its ability to enhance MITF expression and PKA-dependent nuclear β-catenin phosphorylation. Copyright © 2016. Published by Elsevier Ireland Ltd.

The total flavonoids of Clerodendrum bungei suppress A549 cells proliferation, migration, and invasion by impacting Wnt/β-Catenin signaling

Directory of Open Access Journals (Sweden)

Na Yu

2017-01-01

Full Text Available Objectives: The objective of this study is to evaluate the effect of the total flavonoids of Clerodendrum bungei (TFCB on the proliferation, invasion, and metastasis of A549 lung cancer cells through the Wnt signaling pathway. Materials and Methods: A549 cells were transfected with a β-catenin overexpression plasmid and the empty vector pcDNA3.1. The A549 cells were divided into six groups: normal A549 cell group, normal A549 cells with TFCB group, vector control group, vector with TFCB group, β-catenin overexpression group, and β-catenin with TFCB group. We used the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay to detect cell proliferation, a scratch test was used to observe cell migration, and a transwell experiment was employed to evaluate cell invasion. Proteins related to the Wnt pathway were detected with Western blot analysis, including β-catenin, GSK-3 β, P-GSK-3 β, c-Myc, and CyclinD1. Results: The proliferation, invasion, and metastasis of A549 cells were significantly enhanced after being transfected with the β-catenin overexpression plasmid (P < 0.05 or 0.01, accompanied by increased expression of β-catenin, C-Myc, CyclinD1 and reduced expression of Gsk-3 β and P-GSK-3 β. Treatment of cells with TFCB resulted in inhibition of cell proliferation, migration, and invasion; downregulated expression of β-catenin, C-Myc, and CyclinD1; and upregulated expression of GSK-3 β and P-GSK-3 β, especially in the β-catenin overexpression group. Conclusion: TFCB has the potential to inhibit the Wnt/β-catenin pathway by prohibiting the overexpression of β-catenin and regulating its downstream factors.

MASTER-ICATE constraints on the outburst time of OGLE-2012-NOVA-002

Science.gov (United States)

Levato, H.; Saffe, C.; Mallamaci, C.; Lopez, C.; Denisenko, F. Podest D.; Gorbovskoy, E.; Lipunov, V.; Balanutsa, P.; Tiurina, N.; Kornilov, V.; Belinski, A.; Shatskiy, N.; Chazov, V.; Kuznetsov, A.; Zimnukhov, D.; Krushinsky, V.; Zalozhnih, I.; Popov, A.; Bourdanov, A.; Punanova, A.; Ivanov, K.; Yazev, S.; Budnev, N.; Konstantinov, E.; Chuvalaev, O.; Poleshchuk, V.; Gress, O.; Parkhomenko, A.; Tlatov, A.; Dormidontov, D.; Senik, V.; Yurkov, V.; Sergienko, Y.; Varda, D.; Sinyakov, E.; Shumkov, V.; Shurpakov, S.; Podvorotny, P.

2012-10-01

MASTER-ICATE very wide field camera (72-mm f/1.2 lens + 11 Mpx CCD) located at Observatorio Astronomico Felix Aguilar (OAFA) near San Juan, Argentina, has observed the position of possible Nova OGLE-2012-NOVA-002 reported by L. Wyrzykowski et al. (ATel #4483) several times before 2012 May 20 and then again after 2012 July 03. MASTER-WFC is continuously imaging the areas of sky (24x16 sq. deg. field of view) with 5-sec unfiltered exposures.

β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates.

Directory of Open Access Journals (Sweden)

Dany Gaillard

2015-05-01

Full Text Available Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF and posterior circumvallate (CV taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells.

β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates.

Science.gov (United States)

Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E; Barlow, Linda A

2015-05-01

Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells.

Changes of E-cadherin and á-catenin in human and mouse intestinal tumours

Czech Academy of Sciences Publication Activity Database

Šloncová, Eva; Frič, P.; Kučerová, Dana; Lojda, Z.; Tuháčková, Zdena; Sovová, Vlasta

2001-01-01

Roč. 33, č. 1 (2001), s. 13-17 ISSN 0018-2214 R&D Projects: GA ČR GV312/96/K205; GA ČR GA301/00/0269; GA MZd IZ4217 Institutional research plan: CEZ:AV0Z5052915 Keywords : E-cadherin * beta-catenin * intestinal tumours Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.169, year: 2001

Mesenchymal Tumors Can Derive from Ng2/Cspg4-Expressing Pericytes with β-Catenin Modulating the Neoplastic Phenotype

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Shingo Sato

2016-07-01

Full Text Available The cell of origin for most mesenchymal tumors is unclear. One cell type that contributes to this lineages is the pericyte, a cell expressing Ng2/Cspg4. Using lineage tracing, we demonstrated that bone and soft tissue sarcomas driven by the deletion of the Trp53 tumor suppressor, or desmoid tumors driven by a mutation in Apc, can derive from cells expressing Ng2/Cspg4. Deletion of the Trp53 tumor suppressor gene in these cells resulted in the bone and soft tissue sarcomas that closely resemble human sarcomas, while stabilizing β-catenin in this same cell type caused desmoid tumors. Comparing expression between Ng2/Cspg4-expressing pericytes lacking Trp53 and sarcomas that arose from deletion of Trp53 showed inhibition of β-catenin signaling in the sarcomas. Activation of β-catenin inhibited the formation and growth of sarcomas. Thus, pericytes can be a cell of origin for mesenchymal tumors, and β-catenin dysregulation plays an important role in the neoplastic phenotype.

Resveratrol augments the canonical Wnt signaling pathway in promoting osteoblastic differentiation of multipotent mesenchymal cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, Haibin; Shang, Linshan; Li, Xi; Zhang, Xiyu; Gao, Guimin; Guo, Chenhong; Chen, Bingxi; Liu, Qiji [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Gong, Yaoqin, E-mail: yxg8@sdu.edu.cn [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Shao, Changshun, E-mail: shao@biology.rutgers.edu [Key Laboratory of Experimental Teratology, MOE, Institute of Molecular Medicine and Genetics, Shandong University, 44 Wen Hua Xi Lu, Jinan, Shandong 250012 (China); Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States)

2009-10-15

Resveratrol has been shown to possess many health-benefiting effects, including the promotion of bone formation. In this report we investigated the mechanism by which resveratrol promotes osteoblastic differentiation from pluripotent mesenchymal cells. Since Wnt signaling is well documented to induce osteoblastogenesis and bone formation, we characterized the factors involved in Wnt signaling in response to resveratrol treatment. Resveratrol treatment of mesenchymal cells led to an increase in stabilization and nuclear accumulation of {beta}-catenin dose-dependently and time-dependently. As a consequence of the increased nuclear accumulation of {beta}-catenin, the ability to activate transcription of {beta}-catenin-TCF/LEF target genes that are required for osteoblastic differentiation was upregulated. However, resveratrol did not affect the initial step of the Wnt signaling pathway, as resveratrol was as effective in upregulating the activity of {beta}-catenin in cells in which Lrp5 was knocked down as in control cells. In addition, while conditioned medium enriched in Wnt signaling antagonist Dkk1 was able to inhibit Wnt3a-induced {beta}-catenin upregulation, this inhibitory effect can be abolished in resveratrol-treated cells. Furthermore, we showed that the level of glycogen synthase kinase 3{beta} (GSK-3{beta}), which phosphorylates and destabilizes {beta}-catenin, was reduced in response to resveratrol treatment. The phosphorylation of GSK-3{beta} requires extracellular signal-regulated kinase (ERK)1/2. Together, our data indicate that resveratrol promotes osteoblastogenesis and bone formation by augmenting Wnt signaling.

BAMBI Promotes C2C12 Myogenic Differentiation by Enhancing Wnt/β-Catenin Signaling

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Qiangling Zhang

2015-08-01

Full Text Available Bone morphogenic protein and activin membrane-bound inhibitor (BAMBI is regarded as an essential regulator of cell proliferation and differentiation that represses transforming growth factor-β and enhances Wnt/β-catenin signaling in various cell types. However, its role in skeletal muscle remains largely unknown. In the current study, we found that the expression level of BAMBI peaked in the early differentiation phase of the C2C12 rodent myoblast cell line. Knockdown of BAMBI via siRNA inhibited C2C12 differentiation, indicated by repressed MyoD, MyoG, and MyHC expression as well as reductions in the differentiation and fusion indices. BAMBI knockdown reduced the activity of Wnt/β-catenin signaling, as characterized by the decreased nuclear translocation of β-catenin and the lowered transcription of Axin2, which is a well-documented target gene of the Wnt/β-catenin signaling pathway. Furthermore, treatment with LiCl, an activator of Wnt/β-catenin signaling, rescued the reduction in C2C12 differentiation caused by BAMBI siRNA. Taken together, our data suggest that BAMBI is required for normal C2C12 differentiation, and that its role in myogenesis is mediated by the Wnt/β-catenin pathway.

Lack of anti-tumor activity with the β-catenin expression inhibitor EZN-3892 in the C57BL/6J Min/+ model of intestinal carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Hasson, Rian M.; Briggs, Alexandra; Rizvi, Hira; Carothers, Adelaide M.; Davids, Jennifer S.; Bertagnolli, Monica M.; Cho, Nancy L., E-mail: nlcho@partners.org

2014-02-14

Highlights: • Wnt/β-catenin signaling is aberrantly activated in most colorectal cancers. • Locked nucleic acid (LNA)-based antisense is a novel tool for cancer therapy. • β-Catenin inhibition was observed in mature intestinal tissue of LNA-treated mice. • Further investigation of Wnt/β-catenin targeted therapies is warranted. - Abstract: Background: Previously, we showed that short-term inhibition of β-catenin expression and reversal of aberrant β-catenin subcellular localization by the selective COX-2 inhibitor celecoxib is associated with adenoma regression in the C57BL/6J Min/+ mouse. Conversly, long-term administration resulted in tumor resistance, leading us to investigate alternative methods for selective β-catenin chemoprevention. In this study, we hypothesized that disruption of β-catenin expression by EZN-3892, a selective locked nucleic acid (LNA)-based β-catenin inhibitor, would counteract the tumorigenic effect of Apc loss in Min/+ adenomas while preserving normal intestinal function. Materials and methods: C57BL/6J Apc{sup +/+} wild-type (WT) and Min/+ mice were treated with the maximum tolerated dose (MTD) of EZN-3892 (30 mg/kg). Drug effect on tumor numbers, β-catenin protein expression, and nuclear β-catenin localization were determined. Results: Although the tumor phenotype and β-catenin nuclear localization in Min/+ mice did not change following drug administration, we observed a decrease in β-catenin expression levels in the mature intestinal tissue of treated Min/+ and WT mice, providing proof of principle regarding successful delivery of the LNA-based antisense vehicle. Higher doses of EZN-3892 resulted in fatal outcomes in Min/+ mice, likely due to β-catenin ablation in the intestinal tissue and loss of function. Conclusions: Our data support the critical role of Wnt/β-catenin signaling in maintaining intestinal homeostasis and highlight the challenges of effective drug delivery to target disease without permanent

Human I-mfa domain proteins specifically interact with KSHV LANA and affect its regulation of Wnt signaling-dependent transcription

Energy Technology Data Exchange (ETDEWEB)

Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Eizuru, Yoshito [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan)

2010-06-04

Kaposi's sarcoma-associated herpes virus (KSHV)-encoded latency-associated nuclear antigen (LANA) protein has been reported to interact with glycogen synthase kinase 3{beta} (GSK-3{beta}) and to negatively regulate its activity, leading to stimulation of GSK-3{beta}-dependent {beta}-catenin degradation. We show here that the I-mfa domain proteins, HIC (human I-mfa domain-containing protein) and I-mfa (inhibitor of MyoD family a), interacted in vivo with LANA through their C-terminal I-mfa domains. This interaction affected the intracellular localization of HIC, inhibited the LANA-dependent transactivation of a {beta}-catenin-regulated reporter construct, and decreased the level of the LANA.GSK-3{beta} complex. These data reveal for the first time that I-mfa domain proteins interact with LANA and negatively regulate LANA-mediated activation of Wnt signaling-dependent transcription by inhibiting the formation of the LANA.GSK-3{beta} complex.

Identification of Chemical Inhibitors of β-Catenin-Driven Liver Tumorigenesis in Zebrafish.

Directory of Open Access Journals (Sweden)

Kimberley J Evason

2015-07-01

Full Text Available Hepatocellular carcinoma (HCC is one of the most lethal human cancers. The search for targeted treatments has been hampered by the lack of relevant animal models for the genetically diverse subsets of HCC, including the 20-40% of HCCs that are defined by activating mutations in the gene encoding β-catenin. To address this chemotherapeutic challenge, we created and characterized transgenic zebrafish expressing hepatocyte-specific activated β-catenin. By 2 months post fertilization (mpf, 33% of transgenic zebrafish developed HCC in their livers, and 78% and 80% of transgenic zebrafish showed HCC at 6 and 12 mpf, respectively. As expected for a malignant process, transgenic zebrafish showed significantly decreased mean adult survival compared to non-transgenic control siblings. Using this novel transgenic model, we screened for druggable pathways that mediate β-catenin-induced liver growth and identified two c-Jun N-terminal kinase (JNK inhibitors and two antidepressants (one tricyclic antidepressant, amitriptyline, and one selective serotonin reuptake inhibitor that suppressed this phenotype. We further found that activated β-catenin was associated with JNK pathway hyperactivation in zebrafish and in human HCC. In zebrafish larvae, JNK inhibition decreased liver size specifically in the presence of activated β-catenin. The β-catenin-specific growth-inhibitory effect of targeting JNK was conserved in human liver cancer cells. Our other class of hits, antidepressants, has been used in patient treatment for decades, raising the exciting possibility that these drugs could potentially be repurposed for cancer treatment. In support of this proposal, we found that amitriptyline decreased tumor burden in a mouse HCC model. Our studies implicate JNK inhibitors and antidepressants as potential therapeutics for β-catenin-induced liver tumors.

Rhesus lymphocryptovirus latent membrane protein 2A activates β-catenin signaling and inhibits differentiation in epithelial cells

International Nuclear Information System (INIS)

Siler, Catherine A.; Raab-Traub, Nancy

2008-01-01

Rhesus lymphocryptovirus (LCV) is a γ-herpesvirus closely related to Epstein-Barr virus (EBV). The rhesus latent membrane protein 2A (LMP2A) is highly homologous to EBV LMP2A. EBV LMP2A activates the phosphatidylinositol 3-kinase (PI3K) and β-catenin signaling pathways in epithelial cells and affects differentiation. In the present study, the biochemical and biological properties of rhesus LMP2A in epithelial cells were investigated. The expression of rhesus LMP2A in epithelial cells induced Akt activation, GSK3β inactivation and accumulation of β-catenin in the cytoplasm and nucleus. The nuclear translocation, but not accumulation of β-catenin was dependent on Akt activation. Rhesus LMP2A also impaired epithelial cell differentiation; however, this process was not dependent upon Akt activation. A mutant rhesus LMP2A lacking six transmembrane domains functioned similarly to wild-type rhesus LMP2A indicating that the full number of transmembrane domains is not required for effects on β-catenin or cell differentiation. These results underscore the similarity of LCV to EBV and the suitability of the macaque as an animal model for studying EBV pathogenesis

Kinetic studies on the inhibition of Proteus vulgaris beta-lactamase by imipenem.

OpenAIRE

Hashizume, T; Yamaguchi, A; Hirata, T; Sawai, T

1984-01-01

Imipenem was found to inhibit Proteus vulgaris beta-lactamase in a progressive manner. Kinetic experiments confirmed that the inactivated enzyme was not completely recovered after intact imipenem had been exhausted.

ICAT: Development of an Internet-Based Data Collection Method for Ecological Momentary Assessment Using Personal Cell Phones

NARCIS (Netherlands)

Kuntsche, E.N.; Labhart, F.

2013-01-01

Rapid advances in mobile data-transfer technologies offer new possibilities in the use of cell phones to conduct assessments of a person’s natural environment in real time. This paper describes features of a new Internet-based, cell phone-optimized assessment technique (ICAT), which consists of a

Salinomycin inhibits metastatic colorectal cancer growth and interferes with Wnt/β-catenin signaling in CD133+ human colorectal cancer cells

International Nuclear Information System (INIS)

Klose, Johannes; Eissele, Jana; Volz, Claudia; Schmitt, Steffen; Ritter, Alina; Ying, Shen; Schmidt, Thomas; Heger, Ulrike; Schneider, Martin; Ulrich, Alexis

2016-01-01

The polyether antibiotic Salinomycin (Sal) is regarded as an inhibitor of cancer stem cells. Its effectiveness on human colorectal cancer (CRC) cells in vitro has been demonstrated before. The aim of this study was to establish a murine model to investigate the effectiveness of Sal in vivo. Furthermore, we investigated the impact of Sal on Wnt/β-catenin signaling in human CD133 + CRC cells. The two murine CRC cell lines MC38 and CT26 were used to analyze the impact of Sal on tumor cell proliferation, viability, migration, cell cycle progression and cell death in vitro. For in vivo studies, CT26 cells were injected into syngeneic BALB/c mice to initiate (i) subcutaneous, (ii) orthotopic, or (iii) metastatic CRC growth. Sal was administered daily, 5-Fluoruracil served as a control. For mechanistic studies, the CD133 + and CD133 - subpopulations of human CRC cells were separated by flow cytometry and separately exposed to increasing concentrations of Sal. The impact on Wnt/β-catenin signaling was determined by Western blotting and quantitative PCR. Sal markedly impaired tumor cell viability, proliferation and migration, and induced necrotic cell death in vitro. CRC growth in vivo was likewise inhibited upon Sal treatment. Interference with Wnt signaling and reduced expression of the Wnt target genes Fibronectin and Lgr5 indicates a novel molecular mechanism, mediating anti-tumoral effects of Sal in CRC. Sal effectively impairs CRC growth in vivo. Furthermore, Sal acts as an inhibitor of Wnt/β-catenin signaling. Thus, Salinomycin represents a promising candidate for clinical CRC treatment. The online version of this article (doi:10.1186/s12885-016-2879-8) contains supplementary material, which is available to authorized users

Species used for drug testing reveal different inhibition susceptibility for 17beta-hydroxysteroid dehydrogenase type 1.

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Gabriele Möller

Full Text Available Steroid-related cancers can be treated by inhibitors of steroid metabolism. In searching for new inhibitors of human 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD 1 for the treatment of breast cancer or endometriosis, novel substances based on 15-substituted estrone were validated. We checked the specificity for different 17beta-HSD types and species. Compounds were tested for specificity in vitro not only towards recombinant human 17beta-HSD types 1, 2, 4, 5 and 7 but also against 17beta-HSD 1 of several other species including marmoset, pig, mouse, and rat. The latter are used in the processes of pharmacophore screening. We present the quantification of inhibitor preferences between human and animal models. Profound differences in the susceptibility to inhibition of steroid conversion among all 17beta-HSDs analyzed were observed. Especially, the rodent 17beta-HSDs 1 were significantly less sensitive to inhibition compared to the human ortholog, while the most similar inhibition pattern to the human 17beta-HSD 1 was obtained with the marmoset enzyme. Molecular docking experiments predicted estrone as the most potent inhibitor. The best performing compound in enzymatic assays was also highly ranked by docking scoring for the human enzyme. However, species-specific prediction of inhibitor performance by molecular docking was not possible. We show that experiments with good candidate compounds would out-select them in the rodent model during preclinical optimization steps. Potentially active human-relevant drugs, therefore, would no longer be further developed. Activity and efficacy screens in heterologous species systems must be evaluated with caution.

Cytotoxic activities of Telectadium dongnaiense and its constituents by inhibition of the Wnt/β-catenin signaling pathway.

Science.gov (United States)

Kim, Won Kyung; Bach, Duc-Hiep; Ryu, Hyung Won; Oh, Jedo; Park, Hyen Joo; Hong, Ji-Young; Song, Hyuk-Hwan; Eum, Sangmi; Bach, Tran The; Lee, Sang Kook

2017-10-15

Wnt/β-catenin signaling pathway is a potential target for the treatment of human colon cancer. Thus, the inhibitory effects of various plant extracts on cell proliferation and Wnt signal transduction were evaluated to discover a Wnt signaling inhibitor. The present study aimed to investigate the cytotoxicity involved in Wnt pathway of the MeOH extract from Telectadium dongnaiense bark (TDB) and to identify its bioactive constituents by bioassay-guided fractionation. The sulforhodamine B-based proliferation assay and the β-catenin/TCF-responsive reporter gene assay were employed as screening systems. The isolation and identification of compounds were elucidated on the basis of spectroscopic methods. Inhibitory effects on the expression levels of Wnt target genes were determined by real-time PCR and western blotting. The extract of TDB most strongly inhibited cell proliferation and TOPflash activity (IC 50 = 1.5 and 2.0 µg/ml), which was correlated with its inhibitory effects on the expression of Wnt target genes. Three major compounds were isolated from bioactive fractions and were identified as 1,4-dicaffeoylquinic acid (1), quercetin 3-rutinoside (2), and periplocin (3). Only compound 3 showed anti-proliferative activity (IC 50 = 0.06 µM) and exhibited Wnt signaling inhibitory effects in HCT116 colon cancer cells. This study contributes to understanding the cytotoxic properties of TDB extract and its constituents and provides a potent strategy for its further application. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Delamination of neural crest cells requires transient and reversible Wnt inhibition mediated by Dact1/2.

Science.gov (United States)

Rabadán, M Angeles; Herrera, Antonio; Fanlo, Lucia; Usieto, Susana; Carmona-Fontaine, Carlos; Barriga, Elias H; Mayor, Roberto; Pons, Sebastián; Martí, Elisa

2016-06-15

Delamination of neural crest (NC) cells is a bona fide physiological model of epithelial-to-mesenchymal transition (EMT), a process that is influenced by Wnt/β-catenin signalling. Using two in vivo models, we show that Wnt/β-catenin signalling is transiently inhibited at the time of NC delamination. In attempting to define the mechanism underlying this inhibition, we found that the scaffold proteins Dact1 and Dact2, which are expressed in pre-migratory NC cells, are required for NC delamination in Xenopus and chick embryos, whereas they do not affect the motile properties of migratory NC cells. Dact1/2 inhibit Wnt/β-catenin signalling upstream of the transcriptional activity of T cell factor (TCF), which is required for EMT to proceed. Dact1/2 regulate the subcellular distribution of β-catenin, preventing β-catenin from acting as a transcriptional co-activator to TCF, yet without affecting its stability. Together, these data identify a novel yet important regulatory element that inhibits β-catenin signalling, which then affects NC delamination. © 2016. Published by The Company of Biologists Ltd.

Vasculogenesis and angiogenesis initiation under normoxic conditions through Wnt/β-catenin pathway in gliomas.

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Vallée, Alexandre; Guillevin, Rémy; Vallée, Jean-Noël

2018-01-26

The canonical Wnt/β-catenin pathway is up-regulated in gliomas and involved in proliferation, invasion, apoptosis, vasculogenesis and angiogenesis. Nuclear β-catenin accumulation correlates with malignancy. Hypoxia activates hypoxia-inducible factor (HIF)-1α by inhibiting HIF-1α prolyl hydroxylation, which promotes glycolytic energy metabolism, vasculogenesis and angiogenesis, whereas HIF-1α is degraded by the HIF prolyl hydroxylase under normoxic conditions. We focus this review on the links between the activated Wnt/β-catenin pathway and the mechanisms underlying vasculogenesis and angiogenesis through HIF-1α under normoxic conditions in gliomas. Wnt-induced epidermal growth factor receptor/phosphatidylinositol 3-kinase (PI3K)/Akt signaling, Wnt-induced signal transducers and activators of transcription 3 (STAT3) signaling, and Wnt/β-catenin target gene transduction (c-Myc) can activate HIF-1α in a hypoxia-independent manner. The PI3K/Akt/mammalian target of rapamycin pathway activates HIF-1α through eukaryotic translation initiation factor 4E-binding protein 1 and STAT3. The β-catenin/T-cell factor 4 complex directly binds to STAT3 and activates HIF-1α, which up-regulates the Wnt/β-catenin target genes cyclin D1 and c-Myc in a positive feedback loop. Phosphorylated STAT3 by interleukin-6 or leukemia inhibitory factor activates HIF-1α even under normoxic conditions. The activation of the Wnt/β-catenin pathway induces, via the Wnt target genes c-Myc and cyclin D1 or via HIF-1α, gene transactivation encoding aerobic glycolysis enzymes, such as glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production, as the primary alternative of ATP, at all oxygen levels, even in normoxic conditions. Lactate released by glioma cells via the monocarboxylate lactate transporter-1 up-regulated by HIF-1α and lactate anion activates HIF-1α in normoxic endothelial cells by

Fibroblast Growth Factor signaling regulates the expansion of A6-expressing hepatocytes in association with AKT-dependent β-catenin activation

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Utley, Sarah; James, David; Mavila, Nirmala; Nguyen, Marie V.; Vendryes, Christopher; Salisbury, S. Michael; Phan, Jennifer; Wang, Kasper S.

2014-01-01

Background & Aims Fibroblast Growth Factors (FGFs) promote the proliferation and survival of hepatic progenitor cells (HPCs) via AKT-dependent β-catenin activation. Moreover, the emergence of hepatocytes expressing the HPC marker A6 during 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced liver injury is mediated partly by FGF and β-catenin signaling. Herein, we investigate the role of FGF signaling and AKT-mediated β-catenin activation in acute DDC liver injury. Methods Transgenic mice were fed DDC chow for 14 days concurrent with either Fgf10 over-expression or inhibition of FGF signaling via expression of soluble dominant-negative FGF Receptor (R)-2IIIb. Results After 14 days of DDC treatment, there was an increase in periportal cells expressing FGFR1, FGFR2, and AKT-activated phospho-Serine 552 (pSer552) β-CATENIN in association with up-regulation of genes encoding FGFR2IIIb ligands, Fgf7, Fgf10, and Fgf22. In response to Fgf10 over-expression, there was an increase in the number of pSer552-β-CATENIN(positive)+ive periportal cells as well as cells co-positive for A6 and hepatocyte marker, Hepatocyte Nuclear Factor-4α (HNF4α). A similar expansion of A6+ive cells was observed after Fgf10 over-expression with regular chow and after partial hepatectomy during ethanol toxicity. Inhibition of FGF signaling increased the periportal A6+iveHNF4α+ive cell population while reducing centrolobular A6+ive HNF4α+ive cells. AKT inhibition with Wortmannin attenuated FGF10-mediated A6+iveHNF4α+ive cell expansion. In vitro analyses using FGF10 treated HepG2 cells demonstrated AKT-mediated β-CATENIN activation but not enhanced cell migration. Conclusion During acute DDC treatment, FGF signaling promotes the expansion of A6-expressing liver cells partly via AKT-dependent activation of β-CATENIN expansion of A6+ive periportal cells and possibly by reprogramming of centrolobular hepatocytes. PMID:24365171

Xenopus Zic3 controls notochord and organizer development through suppression of the Wnt/β-catenin signaling pathway.

Science.gov (United States)

Fujimi, Takahiko J; Hatayama, Minoru; Aruga, Jun

2012-01-15

Zic3 controls neuroectodermal differentiation and left-right patterning in Xenopus laevis embryos. Here we demonstrate that Zic3 can suppress Wnt/β-catenin signaling and control development of the notochord and Spemann's organizer. When we overexpressed Zic3 by injecting its RNA into the dorsal marginal zone of 2-cell-stage embryos, the embryos lost mesodermal dorsal midline structures and showed reduced expression of organizer markers (Siamois and Goosecoid) and a notochord marker (Xnot). Co-injection of Siamois RNA partially rescued the reduction of Xnot expression caused by Zic3 overexpression. Because the expression of Siamois in the organizer region is controlled by Wnt/β-catenin signaling, we subsequently examined the functional interaction between Zic3 and Wnt signaling. Co-injection of Xenopus Zic RNAs and β-catenin RNA with a reporter responsive to the Wnt/β-catenin cascade indicated that Zic1, Zic2, Zic3, Zic4, and Zic5 can all suppress β-catenin-mediated transcriptional activation. In addition, co-injection of Zic3 RNA inhibited the secondary axis formation caused by ventral-side injection of β-catenin RNA in Xenopus embryos. Zic3-mediated Wnt/β-catenin signal suppression required the nuclear localization of Zic3, and involved the reduction of β-catenin nuclear transport and enhancement of β-catenin degradation. Furthermore, Zic3 co-precipitated with Tcf1 (a β-catenin co-factor) and XIC (I-mfa domain containing factor required for dorsoanterior development). The findings in this report produce a novel system for fine-tuning of Wnt/β-catenin signaling. Copyright © 2011. Published by Elsevier Inc.

Amyloid-beta binds catalase with high affinity and inhibits hydrogen peroxide breakdown.

OpenAIRE

Milton, N G

1999-01-01

Amyloid-beta (Abeta) specifically bound purified catalase with high affinity and inhibited catalase breakdown of H(2)O(2). The Abeta-induced catalase inhibition involved formation of the inactive catalase Compound II and was reversible. CatalaseAbeta interactions provide rapid functional assays for the cytotoxic domain of Abeta and suggest a mechanism for some of the observed actions of Abeta plus catalase in vitro.

18{beta}-Glycyrrhetinic acid inhibits adipogenic differentiation and stimulates lipolysis

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Moon, Myung-Hee; Jeong, Jae-Kyo; Lee, You-Jin; Seol, Jae-Won; Ahn, Dong-Choon; Kim, In-Shik [Center for Healthcare Technology Development, Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Sang-Youel, E-mail: sypark@chonbuk.ac.kr [Center for Healthcare Technology Development, Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2012-04-20

Highlights: Black-Right-Pointing-Pointer 18{beta}-GA inhibits adipogenic differentiation in 3T3-L1 preadipocytes and stimulates lipolysis in differentiated adipocytes. Black-Right-Pointing-Pointer Anti-adipogenic effect of 18{beta}-GA is caused by down-regulation of PPAR{gamma} and inactivation of Akt signalling. Black-Right-Pointing-Pointer Lipolytic effect of 18{beta}-GA is mediated by up-regulation of HSL, ATGL and perilipin and activation of HSL. -- Abstract: 18{beta}-Glycyrrhetinic acid (18{beta}-GA) obtained from the herb liquorice has various pharmacological properties including anti-inflammatory and anti-bacterial activities. However, potential biological anti-obesity activities are unclear. In this study, novel biological activities of 18{beta}-GA in the adipogenesis of 3T3-L1 preadipocytes and in lipolysis of differentiated adipocytes were identified. Mouse 3T3-L1 cells were used as an in vitro model of adipogenesis and lipolysis, using a mixture of insulin/dexamethasone/3-isobutyl-1-methylxanthine (IBMX) to induce differentiation. The amount of lipid droplet accumulation was determined by an AdipoRed assay. The expression of several adipogenic transcription factors and enzymes was investigated using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. 18{beta}-GA dose-dependently (1-40 {mu}M) significantly decreased lipid accumulation in maturing preadipocytes. In 3T3-L1 preadipocytes, 10 {mu}M of 18{beta}-GA down-regulated the transcriptional levels of the peroxisome proliferator-activated receptor {gamma}, CCAAT/enhancer-binding protein {alpha} and adiponectin, which are markers of adipogenic differentiation via Akt phosphorylation. Also, in differentiated adipocytes, 18{beta}-GA increased the level of glycerol release and up-regulated the mRNA of hormone-sensitive lipase, adipose TG lipase and perilipin, as well as the phosphorylation of hormone-sensitive lipase at Serine 563. The results indicate that 18{beta

Overexpression of miR‑21 promotes neural stem cell proliferation and neural differentiation via the Wnt/β‑catenin signaling pathway in vitro.

Science.gov (United States)

Zhang, Wei-Min; Zhang, Zhi-Ren; Yang, Xi-Tao; Zhang, Yong-Gang; Gao, Yan-Sheng

2018-01-01

The primary aim of the present study was to examine the effects of microRNA‑21 (miR‑21) on the proliferation and differentiation of rat primary neural stem cells (NSCs) in vitro. miR‑21 was overexpressed in NSCs by transfection with a miR‑21 mimic. The effects of miR‑21 overexpression on NSC proliferation were revealed by Cell Counting kit 8 and 5‑ethynyl‑2'‑deoxyuridine incorporation assay, and miR‑21 overexpression was revealed to increase NSC proliferation. miR‑21 overexpression was confirmed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). mRNA and protein expression levels of key molecules (β‑catenin, cyclin D1, p21 and miR‑21) in the Wnt/β‑catenin signaling pathway were studied by RT‑qPCR and western blot analysis. RT‑qPCR and western blot analyses revealed that miR‑21 overexpression increased β‑catenin and cyclin D1 expression, and decreased p21 expression. These results suggested that miR‑21‑induced increase in proliferation was mediated by activation of the Wnt/β‑catenin signaling pathway, since overexpression of miR‑21 increased β‑catenin and cyclin D1 expression and reduced p21 expression. Furthermore, inhibition of the Wnt/β‑catenin pathway with FH535 attenuated the influence of miR‑21 overexpression on NSC proliferation, indicating that the factors activated by miR‑21 overexpression were inhibited by FH535 treatment. Furthermore, overexpression of miR‑21 enhanced the differentiation of NSCs into neurons and inhibited their differentiation into astrocytes. The present study indicated that in primary rat NSCs, overexpression of miR‑21 may promote proliferation and differentiation into neurons via the Wnt/β‑catenin signaling pathway in vitro.

MiR-9-5p promotes MSC migration by activating β-catenin signaling pathway.

Science.gov (United States)

Li, Xianyang; He, Lihong; Yue, Qing; Lu, Junhou; Kang, Naixin; Xu, Xiaojing; Wang, Huihui; Zhang, Huanxiang

2017-07-01

Mesenchymal stem cells (MSCs) have the potential to treat various tissue damages, but the very limited number of cells that migrate to the damaged region strongly restricts their therapeutic applications. Full understanding of mechanisms regulating MSC migration will help to improve their migration ability and therapeutic effects. Increasing evidence shows that microRNAs play important roles in the regulation of MSC migration. In the present study, we reported that miR-9-5p was upregulated in hepatocyte growth factor -treated MSCs and in MSCs with high migration ability. Overexpression of miR-9-5p promoted MSC migration, whereas inhibition of endogenous miR-9-5p decreased MSC migration. To elucidate the underlying mechanism, we screened the target genes of miR-9-5p and report for the first time that CK1α and GSK3β, two inhibitors of β-catenin signaling pathway, were direct targets of miR-9-5p in MSCs and that overexpression of miR-9-5p upregulated β-catenin signaling pathway. In line with these data, inhibition of β-catenin signaling pathway by FH535 decreased the miR-9-5p-promoted migration of MSCs, while activation of β-catenin signaling pathway by LiCl rescued the impaired migration of MSCs triggered by miR-9-5p inhibitor. Furthermore, the formation and distribution of focal adhesions as well as the reorganization of F-actin were affected by the expression of miR-9-5p. Collectively, these results demonstrate that miR-9-5p promotes MSC migration by upregulating β-catenin signaling pathway, shedding light on the optimization of MSCs for cell replacement therapy through manipulating the expression level of miR-9-5p. Copyright © 2017 the American Physiological Society.

Direct Targeting of β-Catenin by a Small Molecule Stimulates Proteasomal Degradation and Suppresses Oncogenic Wnt/β-Catenin Signaling

Directory of Open Access Journals (Sweden)

So-Young Hwang

2016-06-01

Full Text Available The Wnt/β-catenin signaling pathway plays a major role in tissue homeostasis, and its dysregulation can lead to various human diseases. Aberrant activation of β-catenin is oncogenic and is a critical driver in the development and progression of human cancers. Despite the significant potential of targeting the oncogenic β-catenin pathway for cancer therapy, the development of specific inhibitors remains insufficient. Using a T cell factor (TCF-dependent luciferase-reporter system, we screened for small-molecule compounds that act against Wnt/β-catenin signaling and identified MSAB (methyl 3-{[(4-methylphenylsulfonyl]amino}benzoate as a selective inhibitor of Wnt/β-catenin signaling. MSAB shows potent anti-tumor effects selectively on Wnt-dependent cancer cells in vitro and in mouse cancer models. MSAB binds to β-catenin, promoting its degradation, and specifically downregulates Wnt/β-catenin target genes. Our findings might represent an effective therapeutic strategy for cancers addicted to the Wnt/β-catenin signaling pathway.

Opposite Interplay Between the Canonical WNT/β-Catenin Pathway and PPAR Gamma: A Potential Therapeutic Target in Gliomas.

Science.gov (United States)

Vallée, Alexandre; Lecarpentier, Yves; Guillevin, Rémy; Vallée, Jean-Noël

2018-06-01

In gliomas, the canonical Wingless/Int (WNT)/β-catenin pathway is increased while peroxisome proliferator-activated receptor gamma (PPAR-γ) is downregulated. The two systems act in an opposite manner. This review focuses on the interplay between WNT/β-catenin signaling and PPAR-γ and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/β-catenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis, tumor growth, and angiogenesis. Activation of PPAR-γ agonists inhibits various signaling pathways such as the JAK/STAT, WNT/β-catenin, and PI3K/Akt pathways, which reduces tumor growth, cell proliferation, cell invasiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs, curcumin, antipsychotic drugs, adiponectin, and sulforaphane downregulate the WNT/β-catenin pathway through the upregulation of PPAR-γ and thus appear to provide an interesting therapeutic approach for gliomas. Temozolomide (TMZ) is an antiangiogenic agent. The downstream action of this opposite interplay may explain the TMZ-resistance often reported in gliomas.

Long non-coding RNA MEG3 inhibits the proliferation and metastasis of oral squamous cell carcinoma by regulating the WNT/β-catenin signaling pathway

OpenAIRE

Liu, Zongxiang; Wu, Cui; Xie, Nina; Wang, Penglai

2017-01-01

This study aimed to investigate how long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) inhibits the growth and metastasis of oral squamous cell carcinoma (OSCC) by regulating WNT/β-catenin signaling pathway in order to explore the antitumor effect of MEG3 and to provide a potential molecular target for the treatment of OSCC. The RT-qPCR technique was used to quantitatively analyze the expression of MEG3 in cancer and adjacent tissues collected from the patients after surgery. Usi...

[Wnt/β-catenin pathway involved in the regulation of rat mesangial cell proliferation by adipose-derived mesenchymal stem cells].

Science.gov (United States)

Li, Zhi; Zhang, Mengying; Li, Xueqin; Lu, Jinming; Xu, Liang

2016-11-01

Objective To investigate the effect of adipose-derived mesenchymal stem cells (ADSCs) on glomerular mesangial cell proliferation via Wnt/β-catenin pathway. Methods The rat glomerular mesangial cells (HBZY-1) were incubated in conditioned ADSC medium. Cell cycle was analyzed with flow cytometry; the proliferation rate of HBZY-1 and the expression levels of relative genes and proteins of Wnt signaling pathway were measured using RNA interference, quantitative real-time PCR and Western blotting, respectively. Results HBZY-1 proliferation was significantly inhibited under the action of conditioned ADSC medium, whereas dickkopf WNT signaling pathway inhibitor 1 (DKK1) mRNA level was up-regulated. Fibronectin and TGF-β1 mRNA expression as well as β-catenin and Bcl-2 protein levels of HBZY-1 were significantly down-regulated. DKK1 gene expression level in ADSCs was significantly higher than that of HBZY-1. After RNA interference, DKK1 expression level in ADSCs was markedly inhibited, yet the β-catenin protein level was notably elevated. The β-catenin and Bcl-2 protein levels of HBZY-1 were also significantly raised in HBZY-1 after cultured with conditioned medium containing ADSCs treated with RNA interference. Conclusion Wnt/β-catenin may be a potential signaling pathway involved in the regulative effect of ADSCs on glomerular mesangial cell proliferation.

4 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT

Science.gov (United States)

2016-09-01

Award Number: W81XWH-15-1-0409 TITLE: 4 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-04094 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT 5c...testicular androgens, testosterone or dihydrotestosterone ( DHT ). Men diagnosed with advanced prostate cancer or failure potentially curative therapy are

Glucocorticoids Inhibit Basal and Hormone-Induced Serotonin Synthesis in Pancreatic Beta Cells.

Directory of Open Access Journals (Sweden)

Moina Hasni Ebou

Full Text Available Diabetes is a major complication of chronic Glucocorticoids (GCs treatment. GCs induce insulin resistance and also inhibit insulin secretion from pancreatic beta cells. Yet, a full understanding of this negative regulation remains to be deciphered. In the present study, we investigated whether GCs could inhibit serotonin synthesis in beta cell since this neurotransmitter has been shown to be involved in the regulation of insulin secretion. To this aim, serotonin synthesis was evaluated in vitro after treatment with GCs of either islets from CD1 mice or MIN6 cells, a beta-cell line. We also explored the effect of GCs on the stimulation of serotonin synthesis by several hormones such as prolactin and GLP 1. We finally studied this regulation in islet in two in vivo models: mice treated with GCs and with liraglutide, a GLP1 analog, and mice deleted for the glucocorticoid receptor in the pancreas. We showed in isolated islets and MIN6 cells that GCs decreased expression and activity of the two key enzymes of serotonin synthesis, Tryptophan Hydroxylase 1 (Tph1 and 2 (Tph2, leading to reduced serotonin contents. GCs also blocked the induction of serotonin synthesis by prolactin or by a previously unknown serotonin activator, the GLP-1 analog exendin-4. In vivo, activation of the Glucagon-like-Peptide-1 receptor with liraglutide during 4 weeks increased islet serotonin contents and GCs treatment prevented this increase. Finally, islets from mice deleted for the GR in the pancreas displayed an increased expression of Tph1 and Tph2 and a strong increased serotonin content per islet. In conclusion, our results demonstrate an original inhibition of serotonin synthesis by GCs, both in basal condition and after stimulation by prolactin or activators of the GLP-1 receptor. This regulation may contribute to the deleterious effects of GCs on beta cells.

LHX6, An Independent Prognostic Factor, Inhibits Lung Adenocarcinoma Progression through Transcriptional Silencing of β-catenin.

Science.gov (United States)

Yang, Juntang; Han, Fei; Liu, Wenbin; Zhang, Mingqian; Huang, Yongsheng; Hao, Xianglin; Jiang, Xiao; Yin, Li; Chen, Hongqiang; Cao, Jia; Zhang, Huidong; Liu, Jinyi

2017-01-01

Introduction: Our previous study identified LIM homeobox domain 6 (LHX6) as a frequently epigenetically silenced tumor-suppressor gene in lung cancer. However, its clinical value has never been evaluated, and the in-depth anti-tumor mechanism remains unclear. Methods: Public database was used for lung cancer, lung adenocarcinoma and lung squamous carcinoma patients and tissue microarray data was used for lung adenocarcinoma patients to study prognostic outcome of LHX6 expression by Kaplan-Meier and Cox-regression analysis. In vitro proliferation, metastasis and in vivo nude mice model were used to evaluate the anti-tumor effect of LHX6 on lung adenocarcinoma cell lines. The mechanisms were explored using western blot, TOP/FOP flash assays and luciferase reporter assays. LHX6 expression and clinical stages data were collected from The Cancer Genome Atlas database (TCGA). Results: Expression of LHX6 was found to be a favorable independent prognostic factor for overall survival (OS) of total lung adenocarcinoma patients (P=0.014) and patients with negative lymph nodes status (P=0.014) but not related the prognostic outcome of lung squamous cell carcinoma patients. The expression status of LHX6 significantly correlated to histological grade (P<0.01), tumor size (P=0.026), lymph node status (P=0.039) and clinical stages (P<0.01) of lung adenocarcinoma patients. Functionally, LHX6 inhibited the proliferation and metastasis of lung adenocarcinoma cells in vitro and in vivo . Furthermore, LHX6 suppressed the Wnt/β-catenin pathway through transcriptionally silencing the expression of β-catenin, and the promoter region (-1161 bp to +27 bp) was crucial for its inhibitory activity. Conclusions: Our data indicate that the expression of LHX6 may serve as a favorable prognostic biomarker for lung adenocarcinoma patients and provide a novel mechanism of LHX6 involving in the tumorigenesis of lung adenocarcinoma.

Hyaluronic acid enhances proliferation of human amniotic mesenchymal stem cells through activation of Wnt/β-catenin signaling pathway

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Liu, Ru-Ming; Sun, Ren-Gang; Zhang, Ling-Tao; Zhang, Qing-Fang; Chen, Dai-Xiong [Guizhou Center for Translational Medicine, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi 563000 (China); Zhong, Jian-Jiang, E-mail: jjzhong@sjtu.edu.cn [State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240 (China); Xiao, Jian-Hui, E-mail: jhxiao@yahoo.com [Guizhou Center for Translational Medicine, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi 563000 (China)

2016-07-15

This study investigated the pro-proliferative effect of hyaluronic acid (HA) on human amniotic mesenchymal stem cells (hAMSCs) and the underlying mechanisms. Treatment with HA increased cell population growth in a dose- and time-dependent manner. Analyses by flow cytometry and immunocytochemistry revealed that HA did not change the cytophenotypes of hAMSCs. Additionally, the osteogenic, chondrogenic, and adipogenic differentiation capabilities of these hAMSCs were retained after HA treatment. Moreover, HA increased the mRNA expressions of wnt1, wnt3a, wnt8a, cyclin D1, Ki-67, and β-catenin as well as the protein level of β-catenin and cyclin D1 in hAMSCs; and the nuclear localization of β-catenin was also enhanced. Furthermore, the pro-proliferative effect of HA and up-regulated expression of Wnt/β-catenin pathway-associated proteins - wnt3a, β-catenin and cyclin D1 in hAMSCs were significantly inhibited upon pre-treatment with Wnt-C59, an inhibitor of the Wnt/β-catenin pathway. These results suggest that HA may positively regulate hAMSCs proliferation through regulation of the Wnt/β-catenin signaling pathway. - Highlights: • Hyaluronic acid (HA) could promote the proliferation of hAMSCs. • HA treatment dose not affect the pluripotency of hAMSCs. • HA increases hAMSCs proliferation through activation of Wnt/β-catenin signaling.

Scopadulciol, Isolated from Scoparia dulcis, Induces β-Catenin Degradation and Overcomes Tumor Necrosis Factor-Related Apoptosis Ligand Resistance in AGS Human Gastric Adenocarcinoma Cells.

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Fuentes, Rolly G; Toume, Kazufumi; Arai, Midori A; Sadhu, Samir K; Ahmed, Firoj; Ishibashi, Masami

2015-04-24

Scopadulciol (1), a scopadulan-type diterpenoid, was isolated from Scoparia dulcis along with three other compounds (2-4) by an activity-guided approach using the TCF reporter (TOP) luciferase-based assay system. A fluorometric microculture cytotoxicity assay (FMCA) revealed that compound 1 was cytotoxic to AGS human gastric adenocarcinoma cells. The treatment of AGS cells with 1 decreased β-catenin levels and also inhibited its nuclear localization. The pretreatment of AGS cells with a proteasome inhibitor, either MG132 or epoxomicin, protected against the degradation of β-catenin induced by 1. The 1-induced degradation of β-catenin was also abrogated in the presence of pifithrin-α, an inhibitor of p53 transcriptional activity. Compound 1 inhibited TOP activity in AGS cells and downregulated the protein levels of cyclin D1, c-myc, and survivin. Compound 1 also sensitized AGS cells to tumor necrosis factor-related apoptosis ligand (TRAIL)-induced apoptosis by increasing the levels of the death receptors, DR4 and DR5, and decreasing the level of the antiapoptotic protein Bcl-2. Collectively, our results demonstrated that 1 induced the p53- and proteasome-dependent degradation of β-catenin, which resulted in the inhibition of TCF/β-catenin transcription in AGS cells. Furthermore, 1 enhanced apoptosis in TRAIL-resistant AGS when combined with TRAIL.

MicroRNA-200a suppresses the Wnt/β-catenin signaling pathway by interacting with β-catenin.

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Su, Juan; Zhang, Anling; Shi, Zhendong; Ma, Feifei; Pu, Peiyu; Wang, Tao; Zhang, Jie; Kang, Chunsheng; Zhang, Qingyu

2012-04-01

The Wnt/β-catenin signaling pathway is crucial for human organ development and is involved in tumor progression of many cancers. Accumulating evidence suggests that the expression of β-catenin is, in part, regulated by specific microRNAs (miRNAs). The purpose of this study was to determine the expression of a recently identified epithelial to mesenchymal transition (EMT)-associated tumor suppressor microRNA (miR)-200a, in cancer cells. We also aimed to identify specific miR-200a target genes and to investigate the antitumor effects of miR-200a on the Wnt/β-catenin signaling pathway. We employed TOP/FOP flash luciferase assays to identify the effect of miR-200a on the Wnt/β-catenin pathway and we confirmed our observations using fluorescence microscopy. To determine target genes of miR-200a, a 3' untranslated region (3' UTR) luciferase assay was performed. Cell viability, invasion and wound healing assays were carried out for functional analysis after miRNA transfection. We further investigated the role of miR-200a in EMT by Western blot analysis. We found fluctuation in the expression of miR-200a that was accompanied by changes in the expression of members of the Wnt/β-catenin signaling pathway. We also determined that miR-200a can directly interact with the 3' UTR of CTNNB1 (the gene that encodes β-catenin) to suppress Wnt/β-catenin signaling. MiR-200a could also influence the biological activities of SGC790 and U251 cells. Our results demonstrate that miR-200a is a new tumor suppressor that can regulate the activity of the Wnt/β-catenin signaling pathway via two mechanisms. MiR-200a is a candidate target for tumor treatment via its regulation of the Wnt/β-catenin signaling pathway.

Tyrosine phosphorylation of LRP6 by Src and Fer inhibits Wnt/β-catenin signalling

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Chen, Qing; Su, Yi; Wesslowski, Janine; Hagemann, Anja I; Ramialison, Mirana; Wittbrodt, Joachim; Scholpp, Steffen; Davidson, Gary

2014-01-01

Low-density lipoprotein receptor-related proteins 5 and 6 (LRP5/6) function as transmembrane receptors to transduce Wnt signals. A key mechanism for signalling is Wnt-induced serine/threonine phosphorylation at conserved PPPSPxS motifs in the LRP6 cytoplasmic domain, which promotes pathway activation. Conserved tyrosine residues are positioned close to all PPPSPxS motifs, which suggests they have a functional significance. Using a cell culture-based cDNA expression screen, we identified the non-receptor tyrosine kinases Src and Fer as novel LRP6 modifiers. Both Src and Fer associate with LRP6 and phosphorylate LRP6 directly. In contrast to the known PPPSPxS Ser/Thr kinases, tyrosine phosphorylation by Src and Fer negatively regulates LRP6-Wnt signalling. Epistatically, they function upstream of β-catenin to inhibit signalling and in agreement with a negative role in regulating LRP6, MEF cells lacking these kinases show enhanced Wnt signalling. Wnt3a treatment of cells enhances tyrosine phosphorylation of endogenous LRP6 and, mechanistically, Src reduces cell surface LRP6 levels and disrupts LRP6 signalosome formation. Interestingly, CK1γ inhibits Fer-induced LRP6 phosphorylation, suggesting a mechanism whereby CK1γ acts to de-represses inhibitory LRP6 tyrosine phosphorylation. We propose that LRP6 tyrosine phosphorylation by Src and Fer serves a negative regulatory function to prevent over-activation of Wnt signalling at the level of the Wnt receptor, LRP6. Subject Categories Membrane & Intracellular Transport; Post-translational Modifications, Proteolysis & Proteomics PMID:25391905

Suppressor of cytokine signalling (SOCS)-3 protects beta cells against IL-1beta-mediated toxicity through inhibition of multiple nuclear factor-kappaB-regulated proapoptotic pathways

DEFF Research Database (Denmark)

Karlsen, Allan Ertman; Heding, P E; Frobøse, H

2004-01-01

The proinflammatory cytokine IL-1beta induces apoptosis in pancreatic beta cells via pathways dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinase, and protein kinase C. We recently showed suppressor of cytokine signalling (SOCS)-3 to be a natural negative feedback reg...... regulator of IL-1beta- and IFN-gamma-mediated signalling in rat islets and beta cell lines, preventing their deleterious effects. However, the mechanisms underlying SOCS-3 inhibition of IL-1beta signalling and prevention against apoptosis remain unknown....

Curcumin Attenuates β-catenin Signaling in Prostate Cancer Cells through Activation of Protein Kinase D1

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Sundram, Vasudha; Chauhan, Subhash C.; Ebeling, Mara; Jaggi, Meena

2012-01-01

Prostate cancer is the most commonly diagnosed cancer affecting 1 in 6 males in the US. Understanding the molecular basis of prostate cancer progression can serve as a tool for early diagnosis and development of novel treatment strategies for this disease. Protein Kinase D1 (PKD1) is a multifunctional kinase that is highly expressed in normal prostate. The decreased expression of PKD1 has been associated with the progression of prostate cancer. Therefore, synthetic or natural products that regulate this signaling pathway can serve as novel therapeutic modalities for prostate cancer prevention and treatment. Curcumin, the active ingredient of turmeric, has shown anti-cancer properties via modulation of a number of different molecular pathways. Herein, we have demonstrated that curcumin activates PKD1, resulting in changes in β-catenin signaling by inhibiting nuclear β-catenin transcription activity and enhancing the levels of membrane β-catenin in prostate cancer cells. Modulation of these cellular events by curcumin correlated with decreased cell proliferation, colony formation and cell motility and enhanced cell-cell aggregation in prostate cancer cells. In addition, we have also revealed that inhibition of cell motility by curcumin is mediated by decreasing the levels of active cofilin, a downstream target of PKD1. The potent anti-cancer effects of curcumin in vitro were also reflected in a prostate cancer xenograft mouse model. The in vivo inhibition of tumor growth also correlated with enhanced membrane localization of β-catenin. Overall, our findings herein have revealed a novel molecular mechanism of curcumin action via the activation of PKD1 in prostate cancer cells. PMID:22523587

Inhibition of melanogenesis by Xanthium strumarium L.

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Li, Hailan; Min, Young Sil; Park, Kyoung-Chan; Kim, Dong-Seok

2012-01-01

Xanthium strumarium L. (Asteraceae) is traditionally used in Korea to treat skin diseases. In this study, we investigated the effects of a X. strumarium stem extract on melanin synthesis. It inhibited melanin synthesis in a concentration-dependent manner, but it did not directly inhibit tyrosinase, the rate-limiting melanogenic enzyme, and instead downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase expression. MITF, the master regulator of pigmentation, is a target of the Wnt signaling pathway, which includes glycogen synthase kinase 3β (GSK3β) and β-catenin. Hence, the influence of X. strumarium stem extract on GSK3β and β-catenin was further investigated. X. strumarium induced GSK3β phosphorylation (inactivation), but the level of β-catenin did not change. Moreover, a specific GSK3β inhibitor restored X. strumarium-induced melanin reduction. Hence, we suggest that X. strumarium inhibits melanin synthesis through downregulation of tyrosinase via GSK3β phosphorylation.

O-GlcNAcylation affects β-catenin and E-cadherin expression, cell motility and tumorigenicity of colorectal cancer.

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Harosh-Davidovich, Shani Ben; Khalaila, Isam

2018-03-01

O-GlcNAcylation, the addition of β-N-acetylglucosamine (O-GlcNAc) moiety to Ser/Thr residues, is a sensor of the cell metabolic state. Cancer diseases such as colon, lung and breast cancer, possess deregulated O-GlcNAcylation. Studies during the last decade revealed that O-GlcNAcylation is implicated in cancer tumorigenesis and proliferation. The Wnt/β-catenin signaling pathway and cadherin-mediated adhesion are also implicated in epithelial-mesenchymal transition (EMT), a key cellular process in invasion and cancer metastasis. Often, deregulation of the Wnt pathway is caused by altered phosphorylation of its components. Specifically, phosphorylation of Ser or Thr residues of β-catenin affects its location and interaction with E-cadherin, thus facilitating cell-cell adhesion. Consistent with previous studies, the current study indicates that β-catenin is O-GlcNAcylated. To test the effect of O-GlcNAcylation on cell motility and how O-GlcNAcylation might affect β-catenin and E-cadherin functions, the enzyme machinery of O-GlcNAcylation was modulated either with chemical inhibitors or by gene silencing. When O-GlcNAcase (OGA) was inhibited, a global elevation of protein O-GlcNAcylation and increase in the expression of E-cadherin and β-catenin were noted. Concomitantly with enhanced O-GlcNAcylation, β-catenin transcriptional activity were elevated. Additionally, fibroblast cell motility was enhanced. Stable silenced cell lines with adenoviral OGA or adenoviral O-GlcNAc transferase (OGT) were established. Consistent with the results obtained by OGA chemical inhibition by TMG, OGT-silencing led to a significant reduction in β-catenin level. In vivo, murine orthotropic colorectal cancer model indicates that elevated O-GlcNAcylation leads to increased mortality rate, tumor and metastasis development. However, reduction in O-GlcNAcylation promoted survival that could be attributed to attenuated tumor and metastasis development. The results described herein provide

Genetic interaction between Pax6 and β-catenin in the developing retinal pigment epithelium

Czech Academy of Sciences Publication Activity Database

Fujimura, Naoko; Klímová, Lucie; Antošová, Barbora; Smolíková, Jana; Machoň, Ondřej; Kozmik, Zbyněk

2015-01-01

Roč. 225, č. 2 (2015), s. 121-128 ISSN 0949-944X R&D Projects: GA ČR GAP305/11/2198; GA ČR GAP305/10/2141; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) LK11214 Institutional support: RVO:68378050 Keywords : Pax6 * beta-Catenin * Retina * Pigmentation * Transdifferentiation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.508, year: 2015

Phosphatase and tensin homolog-β-catenin signaling modulates regulatory T cells and inflammatory responses in mouse liver ischemia/reperfusion injury.

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Zhu, Qiang; Li, Changyong; Wang, Kunpeng; Yue, Shi; Jiang, Longfeng; Ke, Michael; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Zhang, Feng; Lu, Ling; Ke, Bibo

2017-06-01

The phosphatase and tensin homolog (PTEN) deleted on chromosome 10 plays an important role in regulating T cell activation during inflammatory response. Activation of β-catenin is crucial for maintaining immune homeostasis. This study investigates the functional roles and molecular mechanisms by which PTEN-β-catenin signaling promotes regulatory T cell (Treg) induction in a mouse model of liver ischemia/reperfusion injury (IRI). We found that mice with myeloid-specific phosphatase and tensin homolog knockout (PTEN M-KO ) exhibited reduced liver damage as evidenced by decreased levels of serum alanine aminotransferase, intrahepatic macrophage trafficking, and proinflammatory mediators compared with the PTEN-proficient (floxed phosphatase and tensin homolog [PTEN FL/FL ]) controls. Disruption of myeloid PTEN-activated b-catenin promoted peroxisome proliferator-activated receptor gamma (PPARγ)-mediated Jagged-1/Notch signaling and induced forkhead box P3 (FOXP3)1 Tregs while inhibiting T helper 17 cells. However, blocking of Notch signaling by inhibiting γ-secretase reversed myeloid PTEN deficiency-mediated protection in ischemia/reperfusion-triggered liver inflammation with reduced FOXP3 + and increased retinoid A receptor-related orphan receptor gamma t-mediated interleukin 17A expression in ischemic livers. Moreover, knockdown of β-catenin or PPARγ in PTEN-deficient macrophages inhibited Jagged-1/Notch activation and reduced FOXP3 + Treg induction, leading to increased proinflammatory mediators in macrophage/T cell cocultures. In conclusion, our findings demonstrate that PTEN-β-catenin signaling is a novel regulator involved in modulating Treg development and provides a potential therapeutic target in liver IRI. Liver Transplantation 23 813-825 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

Cell polarity development and protein trafficking in hepatocytes lacking E-cadherin/beta-catenin-based adherens junctions

NARCIS (Netherlands)

Theard, Delphine; Steiner, Magdalena; Kalicharan, Dharamdajal; Hoekstra, Dick; van IJzendoorn, Sven C. D.

Using a mutant hepatocyte cell line in which E-cadherin and ss-catenin are completely depleted from the cell surface, and, consequently, fail to form adherens junctions, we have investigated adherens junction requirement for apical-basolateral polarity development and polarized membrane trafficking.

Potential targets of transforming growth factor-beta1 during inhibition of oocyte maturation in zebrafish

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Clelland Eric

2005-09-01

Full Text Available Abstract Background TGF-beta is a multifunctional growth factor involved in regulating a variety of cellular activities. Unlike mammals, the function of TGF-beta in the reproduction of lower vertebrates, such as fish, is not clear. Recently, we showed that TGF-beta1 inhibits gonadotropin- and 17alpha, 20beta-dihydroxyprogesterone (DHP-induced maturation in zebrafish. The aim of the present study was to investigate the mechanisms underlying this action. Method To determine if the effect of TGF-beta1 on oocyte maturation involves transcription and/or translation, ovarian follicles were pre-treated with actinomycin D, a blocker of transcription, and cyclohexamide, an inhibitor of translation, and incubated with hCG or DHP, either alone or in combination with TGF-beta1 and oocyte maturation scored. To determine the effect of TGF-beta1 on mRNA levels of several key effectors of oocyte maturation, three sets of experiments were performed. First, follicles were treated with control medium or TGF-beta1 for 2, 6, 12, and 24 h. Second, follicles were treated with different concentrations of TGF-beta1 (0 to 10 ng/ml for 18 h. Third, follicles were incubated with hCG in the absence or presence of TGF-beta1 for 18 h. At the end of each experiment, total RNA was extracted and reverse transcribed. PCR using primers specific for 20beta-hydroxysteroid dehydrogenase (20beta-HSD which is involved in DHP production, follicle stimulating hormone receptor (FSHR, luteinizing hormone receptor (LHR, the two forms of membrane progestin receptor: mPR-alpha and mPR-beta, as well as GAPDH (control, were performed. Results Treatment with actinomycin D, a blocker of transcription, reduced the inhibitory effect of TGF-beta1 on DHP-induced oocyte maturation, indicating that the inhibitory action of TGF-beta1 is in part due to regulation of gene transcription. Treatment with TGF-beta1 caused a dose and time-dependent decrease in mRNA levels of 20beta-HSD, LHR and mPR-beta in

Activation of estrogen receptor beta (ERβ) regulates the expression of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells.

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Silva, Rafael de Souza; Lombardi, Ana Paola G; de Souza, Deborah Simão; Vicente, Carolina M; Porto, Catarina S

2018-03-01

The aim of the present study was to investigate the impact of the activation of estrogen receptors on expression and localization of N-cadherin, E-cadherin and non-phosphorylated β-catenin in androgen-independent prostate cancer cells (PC-3 and DU-145) and in human post pubertal prostate epithelial cells (PNT1A). Expression of N-cadherin was detected in PNT1A and PC-3 cells, but not in DU-145 cells. E-cadherin was detected only in DU-145 cells and β-catenin was detected in all cells studied. N-cadherin and β-catenin were located preferentially in the cellular membrane of PNT1A cells and in the cytoplasm of PC-3 cells. E-cadherin and β-catenin were located preferentially in the cellular membrane of DU-145 cells. 17β-estradiol (E2) or the ERα-selective agonist PPT did not affect the content and localization of N-cadherin in PC-3 and PNT1A cells or E-cadherin in DU-145 cells. In PC-3 cells, ERβ-selective agonist DPN decreased the expression of N-cadherin. DPN-induced downregulation of N-cadherin was blocked by pretreatment with the ERβ-selective antagonist (PHTPP), indicating that ERβ1 is the upstream receptor regulating the expression of N-cadherin. In DU-145 cells, the activation of ERβ1 by DPN increased the expression of E-cadherin. Taken together, these results suggest that activation of ERβ1 is required to maintain an epithelial phenotype in PC-3 and DU-145 cells. The activation of ERβ1 also increased the expression of β-catenin in cytoplasm of PC-3 and in the cellular membrane of DU-145 cells. In conclusion, our results indicate differential expression and localization of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells. The reduction of N-cadherin content by activation of ERβ, exclusively observed in androgen-independent prostate cancer cells (PC-3), may be related to the activation of signaling pathways, such as the release of β-catenin into the cytoplasm, translocation of β-catenin to the nucleus and

Alkali pH directly activates ATP-sensitive K+ channels and inhibits insulin secretion in beta-cells.

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Manning Fox, Jocelyn E; Karaman, Gunce; Wheeler, Michael B

2006-11-17

Glucose stimulation of pancreatic beta-cells is reported to lead to sustained alkalization, while extracellular application of weak bases is reported to inhibit electrical activity and decrease insulin secretion. We hypothesize that beta-cell K(ATP) channel activity is modulated by alkaline pH. Using the excised patch-clamp technique, we demonstrate a direct stimulatory action of alkali pH on recombinant SUR1/Kir6.2 channels due to increased open probability. Bath application of alkali pH similarly activates native islet beta-cell K(ATP) channels, leading to an inhibition of action potentials, and hyperpolarization of membrane potential. In situ pancreatic perfusion confirms that these cellular effects of alkali pH are observable at a functional level, resulting in decreases in both phase 1 and phase 2 glucose-stimulated insulin secretion. Our data are the first to report a stimulatory effect of a range of alkali pH on K(ATP) channel activity and link this to downstream effects on islet beta-cell function.

Salinomycin repressed the epithelial–mesenchymal transition of epithelial ovarian cancer cells via downregulating Wnt/β-catenin pathway

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Li R

2017-02-01

Full Text Available Rui Li,* Taotao Dong,* Chen Hu, Jingjing Lu, Jun Dai, Peishu Liu Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Jinan, Shandong, People’s Republic of China *These authors contributed equally to this work Abstract: Epithelial ovarian cancer (EOC is the leading cause of death among all gynecological malignancies. Most patients are diagnosed in the advanced stage and have distant metastasis ultimately. Salinomycin has been demonstrated to reduce invasive capacity of multiple tumor cells. The objective of this study was to investigate the effects of salinomycin on EOC cells. The cell counting kit 8 (CCK-8 and Boyden chamber assays showed that salinomycin could effectively reduce the abilities of proliferation, migration and invasion in EOC cells. The western blot assay showed that salinomycin could increase the expression of epithelial markers (E-cadherin and Keratin while decrease the expression of mesenchymal markers (N-cadherin and vimentin in a dose-dependent manner. These results were ascertained by reverse transcription polymerase chain reaction (RT-PCR. Besides, salinomycin could downregulate the expression of proteins associated with the Wnt/β-catenin pathway and repress the nuclear translocation of β-catenin. It was also shown that salinomycin could reverse the aberrant activation of the canonical Wnt pathway induced by GSK-3β inhibitor (SB216763. Our results revealed that salinomycin could inhibit the proliferation, migration and invasion in EOC cells. In addition, the inhibitive effect of salinomycin on the invasive ability was mediated by repressing the epithelial–mesenchymal transition (EMT program, which may be achieved through its inhibition of the Wnt/β-catenin pathway. Keywords: salinomycin, epithelial–mesenchymal transition, epithelial ovarian cancer, Wnt/β-catenin pathway

Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors.

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Shiina, T; Kawasaki, A; Nagao, T; Kurose, H

2000-09-15

The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

Rac1 augments Wnt signaling by stimulating β-catenin–lymphoid enhancer factor-1 complex assembly independent of β-catenin nuclear import

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Jamieson, Cara; Lui, Christina; Brocardo, Mariana G.; Martino-Echarri, Estefania; Henderson, Beric R.

2015-01-01

ABSTRACT β-Catenin transduces the Wnt signaling pathway and its nuclear accumulation leads to gene transactivation and cancer. Rac1 GTPase is known to stimulate β-catenin-dependent transcription of Wnt target genes and we confirmed this activity. Here we tested the recent hypothesis that Rac1 augments Wnt signaling by enhancing β-catenin nuclear import; however, we found that silencing/inhibition or up-regulation of Rac1 had no influence on nuclear accumulation of β-catenin. To better define the role of Rac1, we employed proximity ligation assays (PLA) and discovered that a significant pool of Rac1–β-catenin protein complexes redistribute from the plasma membrane to the nucleus upon Wnt or Rac1 activation. More importantly, active Rac1 was shown to stimulate the formation of nuclear β-catenin–lymphoid enhancer factor 1 (LEF-1) complexes. This regulation required Rac1-dependent phosphorylation of β-catenin at specific serines, which when mutated (S191A and S605A) reduced β-catenin binding to LEF-1 by up to 50%, as revealed by PLA and immunoprecipitation experiments. We propose that Rac1-mediated phosphorylation of β-catenin stimulates Wnt-dependent gene transactivation by enhancing β-catenin–LEF-1 complex assembly, providing new insight into the mechanism of cross-talk between Rac1 and canonical Wnt/β-catenin signaling. PMID:26403202

Inhibiting Vimentin or beta 1-integrin Reverts Prostate Tumor Cells in IrECM and Reduces Tumor Growth

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xueping; Fournier, Marcia V.; Ware, Joy L.; Bissell, Mina J.; Zehner, Zendra E.

2009-07-27

Prostate epithelial cells grown embedded in laminin-rich extracellular matrix (lrECM) undergo morphological changes that closely resemble their architecture in vivo. In this study, growth characteristics of three human prostate epithelial sublines derived from the same cellular lineage, but displaying different tumorigenic and metastatic properties in vivo, were assessed in three-dimensional (3D) lrECM gels. M12, a highly tumorigenic and metastatic subline, was derived from the parental prostate epithelial P69 cell line by selection in nude mice and found to contain a deletion of 19p-q13.1. The stable reintroduction of an intact human chromosome 19 into M12 resulted in a poorly tumorigenic subline, designated F6. When embedded in lrECM gels, the nontumorigenic P69 line produced acini with clearly defined lumena. Immunostaining with antibodies to {beta}-catenin, E-cadherin or {alpha}6-, {beta}4- and {beta}1-integrins showed polarization typical of glandular epithelium. In contrast, the metastatic M12 subline produced highly disorganized cells with no evidence of polarization. The F6 subline reverted to acini-like structures exhibiting basal polarity marked with integrins. Reducing either vimentin levels via siRNA interference or {beta}1-integrin expression by the addition of the blocking antibody, AIIB2, reorganized the M12 subline into forming polarized acini. The loss of vimentin significantly reduced M12-Vim tumor growth when assessed by subcutaneous injection in athymic mice. Thus, tumorigenicity in vivo correlated with disorganized growth in 3D lrECM gels. These studies suggest that the levels of vimentin and {beta}1-integrin play a key role in the homeostasis of the normal acini in prostate and that their dysregulation may lead to tumorigenesis.

beta 1 integrin inhibition dramatically enhances radiotherapy efficacy in human breast cancer xenografts

Energy Technology Data Exchange (ETDEWEB)

Park, Catherine C.; Park, Catherine C.; Zhang, Hui J.; Yao, Evelyn S.; Park, Chong J.; Bissell, Mina J.

2008-06-02

{beta}1 integrin signaling has been shown to mediate cellular resistance to apoptosis after exposure to ionizing radiation (IR). Other signaling molecules that increase resistance include Akt, which promotes cell survival downstream of {beta}1 integrin signaling. We showed previously that {beta}1 integrin inhibitory antibodies, AIIB2, enhance apoptosis and decrease growth in human breast cancer cells in 3 dimensional laminin-rich extracellular matrix (3D lrECM) cultures and in vivo. Here we asked whether AIIB2 could synergize with IR to modify Akt-mediated IR resistance. We used 3D lrECM cultures to test the optimal combination of AIIB2 with IR treatment of two breast cancer cell lines, MCF-7 and HMT3522-T4-2, as well as T4-2 myr-Akt breast cancer colonies or HMT3522-S-1, which form normal organotypic structures in 3D lrECM. Colonies were assayed for apoptosis and {beta}1 integrin/Akt signaling pathways were evaluated using western blot. In addition, mice bearing MCF-7 xenografts were used to validate the findings in 3D lrECM. We report that AIIB2 increased apoptosis optimally post-IR by down regulating Akt in breast cancer colonies in 3D lrECM. In vivo, addition of AIIB2 after IR significantly enhanced tumor growth inhibition and apoptosis compared to either treatment alone. Remarkably, the degree of tumor growth inhibition using AIIB2 plus 2 Gy radiation was similar to that of 8 Gy alone. We showed previously that AIIB2 had no discernible toxicity in mice; here, its addition allowed for a significant reduction in the IR dose that was necessary to achieve comparable growth inhibition and apoptosis in breast cancer xenografts in vivo.

Sclerostin inhibition promotes TNF-dependent inflammatory joint destruction

NARCIS (Netherlands)

Wehmeyer, C.; Frank, S.; Beckmann, D.; Bottcher, M.; Cromme, C.; Konig, U.; Fennen, M.; Held, A.; Paruzel, P.; Hartmann, C.; Stratis, A.; Korb-Pap, A.; Kamradt, T.; Kramer, I.; Berg, W.B. van den; Kneissel, M.; Pap, T.; Dankbar, B.

2016-01-01

Sclerostin, an inhibitor of the Wnt/beta-catenin pathway, has anti-anabolic effects on bone formation by negatively regulating osteoblast differentiation. Mutations in the human sclerostin gene (SOST) lead to sclerosteosis with progressive skeletal overgrowth, whereas sclerostin-deficient

Adenomatous polyposis coli (APC) regulates miR17-92 cluster through β-catenin pathway in colorectal cancer.

Science.gov (United States)

Li, Yajuan; Lauriola, Mattia; Kim, Donghwa; Francesconi, Mirko; D'Uva, Gabriele; Shibata, Dave; Malafa, Mokenge P; Yeatman, Timothy J; Coppola, Domenico; Solmi, Rossella; Cheng, Jin Q

2016-09-01

Adenomatous polyposis coli (APC) mutation is the most common genetic change in sporadic colorectal cancer (CRC). Although deregulations of miRNAs have been frequently reported in this malignancy, APC-regulated miRNAs have not been extensively documented. Here, by using an APC-inducible cell line and array analysis, we identified a total of 26 deregulated miRNAs. Among them, members of miR-17-92 cluster were dramatically inhibited by APC and induced by enforced expression of β-catenin. Furthermore, we demonstrate that activated β-catenin resulted from APC loss binds to and activates the miR-17-92 promoter. Notably, enforced expression of miR-19a overrides APC tumor suppressor activity, and knockdown of miR-19a in cancer cells with compromised APC function reduced their aggressive features in vitro. Finally, we observed that expression of miR-19a significantly correlates with β-catenin levels in colorectal cancer specimens, and it is associated to the aggressive stage of tumor progression. Thus, our study reveals that miR-17-92 cluster is directly regulated by APC/β-catenin pathway and could be a potential therapeutic target in colon cancers with aberrant APC/β-catenin signaling.

Concurrent Transient Activation of Wnt/β-Catenin Pathway Prevents Radiation Damage to Salivary Glands

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Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu; Boyer, Arthur; Liu, Fei

2012-01-01

Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/β-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/β-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/β-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/β-catenin pathway could prevent radiation-induced salivary gland dysfunction.

Identification of Androgen Receptor and Beta-Catenin Target Genes in Prostate and Prostate Cancer

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2013-10-01

Anderson A, Yang GY, Arbeit JM, and Auborn KJ. Indole- 3-carbinol prevents cervical cancer in human papilloma virus type 16 (HPV16) transgenic mice...signaling is prevalent in many cancers, most notably colorectal cancer; however their role in prostate cancer is becoming increasingly appreciated...condition 2 gives no background bands. F) Schematic of human PSA promoter and or β-catenin binding sites (TBE). G-H) Target specific PCR for PSA (G) or

β‑catenin nuclear translocation induced by HIF‑1α overexpression leads to the radioresistance of prostate cancer.

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Luo, Yong; Li, Mingchuan; Zuo, Xuemei; Basourakos, Spyridon P; Zhang, Jiao; Zhao, Jiahui; Han, Yili; Lin, Yunhua; Wang, Yongxing; Jiang, Yongguang; Lan, Ling

2018-04-12

Hypoxia-inducible factor‑1α (HIF‑1α) is known to play crucial roles in tumor radioresistance; however, the molecular mechanisms responsible for the promotion of tumor radioresistance by HIF‑1α remain unclear. β‑catenin is known to be involved in the metastatic potential of prostate cancer (PCa). In this study, to investigate the role of HIF‑1α and β‑catenin in the radioresistance of PCa, two PCa cell lines, LNCaP and C4‑2B, were grouped as follows: Negative control (no treatment), HIF‑1α overexpression group (transfected with HIF‑1α overexpression plasmid) and β‑catenin silenced group (transfected with HIF‑1α plasmids and β‑catenin-shRNA). Cell proliferation, cell cycle, cell invasion and radiosensitivity were examined under normal or hypoxic conditions. In addition, radiosensitivity was examined in two mouse PCa models (the LNCaP orthotopic BALB/c-nu mice model and the C4‑2B subcutaneous SCID mice model). Our results revealed that in both the LNCaP and C4‑2B cells, transfection with HIF‑1α overexpression plasmid led to an enhanced β‑catenin nuclear translocation, while β‑catenin silencing inhibited β‑catenin nuclear translocation. The enhanced β‑catenin nuclear translocation induced by HIF‑1α overexpression resulted in an enhanced cell proliferation and cell invasion, an altered cell cycle distribution, decreased apoptosis, and improved non‑homologous end joining (NHEJ) repair under normal and irradiation conditions. Similar results were observed in the animal models. HIF‑1α overexpression enhanced β‑catenin nuclear translocation, which led to the activation of the β‑catenin/NHEJ signaling pathway and increased cell proliferation, cell invasion and DNA repair. These results thus suggest that HIF‑1α overexpression promotes the radioresistance of PCa cells.

Destabilization of Heterologous Proteins Mediated by the GSK3β Phosphorylation Domain of the β-Catenin Protein

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Yuhan Kong

2013-11-01

Full Text Available Background and Aims: Wnt/β-catenin signaling plays important roles in development and cellular processes. The hallmark of canonical Wnt signaling activation is the stabilization of β-catenin protein in cytoplasm and/or nucleus. The stability of β-catenin is the key to its biological functions and is controlled by the phosphorylation of its amino-terminal degradation domain. Aberrant activation of β-catenin signaling has been implicated in the development of human cancers. It has been recently suggested that GSK3βmay play an essential role in regulating global protein turnover. Here, we investigate if the GSK3β phosphorylation site-containing degradation domain of β-catenin is sufficient to destabilize heterologous proteins. Methods and Results: We engineer chimeric proteins by fusing β-catenin degradation domain at the N- and/or C-termini of the enhanced green fluorescent protein (eGFP. In both transient and stable expression experiments, the chimeric GFP proteins exhibit a significantly decreased stability, which can be effectively antagonized by lithium and Wnt1. An activating mutation in the destruction domain significantly stabilizes the fusion protein. Furthermore, GSK3 inhibitor SB-216763 effectively increases the GFP signal of the fusion protein. Conversely, the inhibition of Wnt signaling with tankyrase inhibitor XAV939 results in a decrease in GFP signal of the fusion proteins, while these small molecules have no significant effects on the mutant destruction domain-GFP fusion protein. Conclusion: Our findings strongly suggest that the β-catenin degradation domain may be sufficient to destabilize heterologous proteins in Wnt signaling-dependent manner. It is conceivable that the chimeric GFP proteins may be used as a functional reporter to measure the dynamic status of β-catenin signaling, and to identify potential anticancer drugs that target β-catenin signaling.

β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

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Eiring, A M; Khorashad, J S; Anderson, D J; Yu, F; Redwine, H M; Mason, C C; Reynolds, K R; Clair, P M; Gantz, K C; Zhang, T Y; Pomicter, A D; Kraft, I L; Bowler, A D; Johnson, K; Partlin, M Mac; O'Hare, T; Deininger, M W

2015-12-01

Activation of nuclear β-catenin and expression of its transcriptional targets promotes chronic myeloid leukemia (CML) progression, tyrosine kinase inhibitor (TKI) resistance, and leukemic stem cell self-renewal. We report that nuclear β-catenin has a role in leukemia cell-intrinsic but not -extrinsic BCR-ABL1 kinase-independent TKI resistance. Upon imatinib inhibition of BCR-ABL1 kinase activity, β-catenin expression was maintained in intrinsically resistant cells grown in suspension culture and sensitive cells cultured in direct contact (DC) with bone marrow (BM) stromal cells. Thus, TKI resistance uncouples β-catenin expression from BCR-ABL1 kinase activity. In β-catenin reporter assays, intrinsically resistant cells showed increased transcriptional activity versus parental TKI-sensitive controls, and this was associated with restored expression of β-catenin target genes. In contrast, DC with BM stromal cells promoted TKI resistance, but had little effects on Lef/Tcf reporter activity and no consistent effects on cytoplasmic β-catenin levels, arguing against a role for β-catenin in extrinsic TKI resistance. N-cadherin or H-cadherin blocking antibodies abrogated DC-based resistance despite increasing Lef/Tcf reporter activity, suggesting that factors other than β-catenin contribute to extrinsic, BM-derived TKI resistance. Our data indicate that, while nuclear β-catenin enhances survival of intrinsically TKI-resistant CML progenitors, it is not required for extrinsic resistance mediated by the BM microenvironment.

Regulatory effect of evodiamine on the malignant biological behaviors and Wnt/β-catenin signaling pathway of colorectal cancer cell lines HT29

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Yuan-Hui Wang

2016-04-01

Full Text Available Objective: To study the regulatory effect of evodiamine on the malignant biological behaviors and Wnt/β-catenin signaling pathway of colorectal cancer cell lines HT29. Methods: Colorectal cancer cell lines HT29 were cultured and divided into blank control group and evodiamine group, and after different treatment, cell viability, proportion of different cell cycle as well as the contents of VEGFA, VEGFB, VEGFC, MMP3, MMP14, Wnt and β-catenin were detected. Results: (1 Cell viability: MTT value of evodiamine group was significantly lower than that of blank control group; (2 Cell cycle: proportion of both S phase and G2/M phase of evodiamine group were lower than those of blank control group, and proportion of G0/ G1 phase was higher than that of blank control group; (3 VEGF and MMP contents: VEGFA, VEGFB, VEGFC, MMP3 and MMP14 contents of evodiamine group were lower than those of blank control group; (4 Wnt/β-catenin signaling pathway: Wnt and β-catenin contents of evodiamine group were lower than those of blank control group. Conclusion: Evodiamine can inhibit the proliferation of colorectal cancer cell lines HT29 and down-regulate the expression of VEGF and MMP, and the effect may be achieved by inhibiting the activation of Wnt/β-catenin signaling pathway.

Frequent β-catenin gene mutations in atypical polypoid adenomyoma of the uterus.

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Takahashi, Hiroyuki; Yoshida, Tsutomu; Matsumoto, Toshihide; Kameda, Yoichi; Takano, Yasuo; Tazo, Yuki; Inoue, Hisako; Saegusa, Makoto

2014-01-01

Atypical polypoid adenomyoma (APA) is an uncommon polypoid lesion of the uterus. To clarify the mechanism of its histogenesis, we examined the functional role of β-catenin, with reference to expression of p21(waf1), cyclin D1, cyclin E, CD10, and α-smooth muscle actin (SMA), as well as cell proliferation, in 7 lesions. In the epithelial components, expression of nuclear β-catenin, p21(waf1), and cyclin D1 was increased in a stepwise fashion from normal tissue through complex atypical hyperplasia and adenomyoma to APA lesions, particularly in squamous morular areas, whereas cell proliferation, as well as cyclin E expression, was significantly decreased in the latter. Similar findings were evident in the stromal lesions, with the exception of a case of nuclear β-catenin. In addition, coexpression of CD10 and α-SMA markers was observed in the stromal components in 3 APA cases, in line with the results of normal secretory endometrial and adenomyoma samples, suggesting that cells progress to myofibromatous cells in response to differentiation-promoting events. Finally, β-catenin gene (CTNNB1) mutations were detected in all APA cases, the single nucleotide substitutions being in the epithelial but not the stromal components. These findings suggest that activation of β-catenin signaling, probably secondary to the gene abnormalities, plays an important role in the formation of the complex epithelial architecture in APAs, leading to inhibition of cell proliferation through overexpression of p21(waf1). In contrast, changes in the stromal cell phenotype may occur through a shift from CD10 to α-SMA immunopositivity, independent of CTNNB1 status. © 2013.

Curcumin inhibits oral squamous cell carcinoma SCC-9 cells proliferation by regulating miR-9 expression

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Xiao, Can [Department of Occupational Medicine and Environmental Health, School of Public Health, Soochow University, Suzhou 215123 (China); Department of Stomatology, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Wang, Lili; Zhu, Lifang [Department of Stomatology, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Zhang, Chenping, E-mail: zhang_cping@163.com [Department of Head and Neck Tumors, Shanghai Ninth People’s Hospital Affiliated Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China); Zhou, Jianhua [Department of Occupational Medicine and Environmental Health, School of Public Health, Soochow University, Suzhou 215123 (China)

2014-11-28

Highlights: • miR-9 expression level was significantly decreased in OSCC tissues. • Curcumin significantly inhibited SCC-9 cells proliferation. • miR-9 mediates the inhibition of SCC-9 proliferation by curcumin. • Curcumin suppresses Wnt/β-catenin signaling in SCC-9 cells. • miR-9 mediates the suppression of Wnt/β-catenin signaling by curcumin. - Abstract: Curcumin, a phytochemical derived from the rhizome of Curcuma longa, has shown anticancer effects against a variety of tumors. In the present study, we investigated the effects of curcumin on the miR-9 expression in oral squamous cell carcinoma (OSCC) and explored the potential relationships between miR-9 and Wnt/β-catenin pathway in curcumin-mediated OSCC inhibition in vitro. As the results shown, the expression levels of miR-9 were significantly lower in clinical OSCC specimens than those in the adjacent non-tumor tissues. Furthermore, our results indicated that curcumin inhibited OSCC cells (SCC-9 cells) proliferation through up-regulating miR-9 expression, and suppressing Wnt/β-catenin signaling by increasing the expression levels of the GSK-3β, phosphorylated GSK-3β and β-catenin, and decreasing the cyclin D1 level. Additionally, the up-regulation of miR-9 by curcumin in SCC-9 cells was significantly inhibited by delivering anti-miR-9 but not control oligonucleotides. Downregulation of miR-9 by anti-miR-9 not only attenuated the growth-suppressive effects of curcumin on SCC-9 cells, but also re-activated Wnt/β-catenin signaling that was inhibited by curcumin. Therefore, our findings would provide a new insight into the use of curcumin against OSCC in future.

Curcumin inhibits oral squamous cell carcinoma SCC-9 cells proliferation by regulating miR-9 expression

International Nuclear Information System (INIS)

Xiao, Can; Wang, Lili; Zhu, Lifang; Zhang, Chenping; Zhou, Jianhua

2014-01-01

Highlights: • miR-9 expression level was significantly decreased in OSCC tissues. • Curcumin significantly inhibited SCC-9 cells proliferation. • miR-9 mediates the inhibition of SCC-9 proliferation by curcumin. • Curcumin suppresses Wnt/β-catenin signaling in SCC-9 cells. • miR-9 mediates the suppression of Wnt/β-catenin signaling by curcumin. - Abstract: Curcumin, a phytochemical derived from the rhizome of Curcuma longa, has shown anticancer effects against a variety of tumors. In the present study, we investigated the effects of curcumin on the miR-9 expression in oral squamous cell carcinoma (OSCC) and explored the potential relationships between miR-9 and Wnt/β-catenin pathway in curcumin-mediated OSCC inhibition in vitro. As the results shown, the expression levels of miR-9 were significantly lower in clinical OSCC specimens than those in the adjacent non-tumor tissues. Furthermore, our results indicated that curcumin inhibited OSCC cells (SCC-9 cells) proliferation through up-regulating miR-9 expression, and suppressing Wnt/β-catenin signaling by increasing the expression levels of the GSK-3β, phosphorylated GSK-3β and β-catenin, and decreasing the cyclin D1 level. Additionally, the up-regulation of miR-9 by curcumin in SCC-9 cells was significantly inhibited by delivering anti-miR-9 but not control oligonucleotides. Downregulation of miR-9 by anti-miR-9 not only attenuated the growth-suppressive effects of curcumin on SCC-9 cells, but also re-activated Wnt/β-catenin signaling that was inhibited by curcumin. Therefore, our findings would provide a new insight into the use of curcumin against OSCC in future

Discovery of novel small molecule activators of β-catenin signaling.

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Folkert Verkaar

Full Text Available Wnt/β-catenin signaling plays a major role in embryonic development and adult stem cell maintenance. Reduced activation of the Wnt/β-catenin pathway underlies neurodegenerative disorders and aberrations in bone formation. Screening of a small molecule compound library with a β-galactosidase fragment complementation assay measuring β-catenin nuclear entry revealed bona fide activators of β-catenin signaling. The compounds stabilized cytoplasmic β-catenin and activated β-catenin-dependent reporter gene activity. Although the mechanism through which the compounds activate β-catenin signaling has yet to be determined, several key regulators of Wnt/β-catenin signaling, including glycogen synthase kinase 3 and Frizzled receptors, were excluded as the molecular target. The compounds displayed remarkable selectivity, as they only induced β-catenin signaling in a human osteosarcoma U2OS cell line and not in a variety of other cell lines examined. Our data indicate that differences in cellular Wnt/β-catenin signaling machinery can be exploited to identify cell type-specific activators of Wnt/β-catenin signaling.

Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

International Nuclear Information System (INIS)

Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo; Lee, Jeong-Chae; Shi, Xianglin

2013-01-01

Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr

Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); School of Dentistry and Institute of Oral Biosciences, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)

2013-09-01

Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr

β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

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Yang CM

2017-02-01

Full Text Available Chun-ming Yang,1 Shan Ji,2 Yan Li,3 Li-ye Fu,3 Tao Jiang,3 Fan-dong Meng31Department of Urology, The First Affiliated Hospital, China Medical University, 2Department of Endocrinology, The Fifth People’s Hospital of Shenyang, 3Department of Biotherapy, Cancer Research Institute, The First Affiliated Hospital, China Medical University, Shenyang, ChinaAbstract: β-Catenin (CTNNB1 gene coding protein is a component of the Wnt signaling pathway that has been shown to play an important role in the formation of certain cancers. Abnormal accumulation of CTNNB1 contributes to most cancers. This research studied the involvement of β-catenin in renal cell carcinoma (RCC cell proliferation, apoptosis, migration, and invasion. Proliferation, cell cycle, and apoptosis were analyzed by using Cell Counting Kit-8 and by flow cytometry. Migration and invasion assays were measured by transwell analysis. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of CTNNB1, ICAM-1, VCAM-1, CXCR4, and CCL18 in RCC cell lines. It was found that CTNNB1 knockdown inhibited cell proliferation, migration, and invasion and induced apoptosis of A-498 cells. CTNNB1 overexpression promoted cell proliferation, migration, and invasion and inhibited apoptosis of 786-O cells. Moreover, knockdown of CTNNB1 decreased the levels of ICAM-1, VCAM-1, CXCR4, and CCL18 expression, but CTNNB1 overexpression increased the expression of ICAM-1, VCAM-1, CXCR4, and CCL18. Further in vivo tumor formation study in nude mice indicated that inhibition of CTNNB1 delayed the progress of tumor formation through inhibiting PCNA and Ki67 expression. These results indicate that CTNNB1 could act as an oncogene and may serve as a promising therapeutic strategy for RCC.Keywords: kidney cancer, oncogene, β-catenin, survival time, tumor migration-related protein

Multiple interactions between maternally-activated signalling pathways control Xenopus nodal-related genes.

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Rex, Maria; Hilton, Emma; Old, Robert

2002-03-01

We have investigated the induction of the six Xenopus nodal-related genes, Xnr1-Xnr6, by maternal determinants. The beta-catenin pathway was modelled by stimulation using Xwnt8, activin-like signalling was modelled by activin, and VegT action was studied by overexpression in animal cap explants. Combinations of factors were examined, and previously unrecognised interactions were revealed in animal caps and whole embryos. For the induction of Xnr5 and Xnr6 in whole embryos, using a beta-catenin antisense morpholino oligonucleotide or a dominant negative XTcf3, we have demonstrated an absolute permissive requirement for the beta-catenin/Tcf pathway, in addition to the requirement for VegT action. In animal caps Xnr5 and Xnr6 are induced in response to VegT overexpression, and this induction is dependent upon the concomitant activation of the beta-catenin pathway that VegT initiates in animal caps. For the induction of Xnr3, VegT interacts negatively so as to inhibit the induction otherwise observed with wnt-signalling alone. The negative effect of VegT is not the result of a general inhibition of wnt-signalling, and does not result from an inhibition of wnt-induced siamois expression. A 294 bp proximal promoter fragment of the Xnr3 gene is sufficient to mediate the negative effect of VegT. Further experiments, employing cycloheximide to examine the dependence of Xnr gene expression upon proteins translated after the mid-blastula stage, demonstrated that Xnrs 4, 5 and 6 are 'primary' Xnr genes whose expression in the late blastula is solely dependent upon factors present before the mid-blastula stage.

Matrix metalloproteinase inhibition delays wound healing and blocks the latent transforming growth factor-beta1-promoted myofibroblast formation and function

DEFF Research Database (Denmark)

Mirastschijski, Ursula; Schnabel, Reinhild; Claes, Juliane

2010-01-01

applied topically to full-thickness skin excisional wounds in rats and its ability to inhibit the promotion of myofibroblast formation and function by the latent transforming-growth factor-beta1 (TGF-beta1). BB-94 delayed wound contraction, as well as all other associated aspects of wound healing examined......, including myofibroblast formation, stromal cell proliferation, blood vessel formation, and epithelial wound coverage. Interestingly, BB-94 dramatically increased the level of latent and active MMP-9. The increased levels of active MMP-9 may eventually overcome the ability of BB-94 to inhibit this MMP...... and may explain why wound contraction and other associated events of wound healing were only delayed and not completely inhibited. BB-94 was also found to inhibit the ability of latent TGF-beta1 to promote the formation and function of myofibroblasts. These results suggest that BB-94 could delay wound...

Wnt/β-Catenin Signaling Regulates the Expression of the Ammonium Permease Gene RHBG in Human Cancer Cells.

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Ahmad Merhi

Full Text Available Ammonium is a metabolic waste product mainly detoxified by the liver. Hepatic dysfunction can lead to cytotoxic accumulation of circulating ammonium and to subsequent encephalopathy. Transmembrane ammonium transport is a widely spread process ensured by the highly conserved proteins of the Mep-Amt-Rh superfamily, including the mammalian Rhesus (Rh factors. The regulatory mechanisms involved in the control of RH genes expression remain poorly studied. Here we addressed the expression regulation of one of these factors, RHBG. We identify HepG2 hepatocellular carcinoma cells and SW480 colon adenocarcinoma cells as expressing RHBG and show that its expression relies on β-catenin signaling. siRNA-mediated β-catenin knockdown resulted in significant reduction of RHBG mRNA in both cell lines. Pharmaceutical inhibition of the TCF4/β-catenin interaction or knockdown of the transcription factor TCF4 also downregulated RHBG expression. We identify a minimal RHBG regulatory sequence displaying a promoter activity and show that β-catenin and TCF4 bind to this fragment in vivo. We finally characterize the role of potential TCF4 binding sites in RHBG regulation. Taken together, our results indicate RHBG expression as a direct target of β-catenin regulation, a pathway frequently deregulated in many cancers and associated with tumorigenesis.

Melatonin Inhibits Neural Cell Apoptosis and Promotes Locomotor Recovery via Activation of the Wnt/β-Catenin Signaling Pathway After Spinal Cord Injury.

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Shen, Zhaoliang; Zhou, Zipeng; Gao, Shuang; Guo, Yue; Gao, Kai; Wang, Haoyu; Dang, Xiaoqian

2017-08-01

The spinal cord is highly sensitive to spinal cord injury (SCI) by external mechanical damage, resulting in irreversible neurological damage. Activation of the Wnt/β-catenin signaling pathway can effectively reduce apoptosis and protect against SCI. Melatonin, an indoleamine originally isolated from bovine pineal tissue, exerts neuroprotective effects after SCI through activation of the Wnt/β-catenin signaling pathway. In this study, we demonstrated that melatonin exhibited neuroprotective effects on neuronal apoptosis and supported functional recovery in a rat SCI model by activating the Wnt/β-catenin signaling pathway. We found that melatonin administration after SCI significantly upregulated the expression of low-density lipoprotein receptor related protein 6 phosphorylation (p-LRP-6), lymphoid enhancer factor-1 (LEF-1) and β-catenin protein in the spinal cord. Melatonin enhanced motor neuronal survival in the spinal cord ventral horn and improved the locomotor functions of rats after SCI. Melatonin administration after SCI also reduced the expression levels of Bax and cleaved caspase-3 in the spinal cord and the proportion of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) positive cells, but increased the expression level of Bcl-2. These results suggest that melatonin attenuated SCI by activating the Wnt/β-catenin signaling pathway.

beta-Arrestin Interacts with the Beta/Gamma Subunits of Trimeric G-Proteins and Dishevelled in the Wnt/Ca2+ Pathway in Xenopus Gastrulation

Czech Academy of Sciences Publication Activity Database

Seitz, K.; Dursch, V.; Harnoš, J.; Bryja, Vítězslav; Gentzel, M.; Schambony, A.

2014-01-01

Roč. 9, č. 1 (2014) E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GC204/09/J030 Grant - others:GA ČR(CZ) GA204/09/0498 Institutional support: RVO:68081707 Keywords : CONVERGENT EXTENSION MOVEMENTS * WNT SIGNALING PATHWAYS * WNT/BETA-CATENIN Subject RIV: BO - Biophysics Impact factor: 3.234, year: 2014

In vitro effects of a small-molecule antagonist of the Tcf/ß-catenin complex on endometrial and endometriotic cells of patients with endometriosis.

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Sachiko Matsuzaki

Full Text Available BACKGROUND: Our previous studies suggested that aberrant activation of Wnt/ß-catenin signaling might be involved in the pathophysiology of endometriosis. We hypothesized that inhibition of Wnt/ß-catenin signaling might result in inhibition of cell proliferation, migration, and/or invasion of endometrial and endometriotic epithelial and stromal cells of patients with endometriosis. OBJECTIVES: The aim of the present study was to evaluate the effects of a small-molecule antagonist of the Tcf/ß-catenin complex (PKF 115-584 on cell proliferation, migration, and invasion of endometrial and endometriotic epithelial and stromal cells. METHODS: One hundred twenty-six patients (78 with and 48 without endometriosis with normal menstrual cycles were recruited. In vitro effects of PKF 115-584 on cell proliferation, migration, and invasion and on the Tcf/ß-catenin target genes were evaluated in endometrial epithelial and stromal cells of patients with and without endometriosis, and in endometrial and endometriotic epithelial and stromal cells of the same patients. RESULTS: The inhibitory effects of PKF 115-584 on cell migration and invasion in endometrial epithelial and stromal cells of patients with endometriosis prepared from the menstrual phase were significantly higher than those of patients without endometriosis. Levels of total and active forms of MMP-9 were significantly higher in epithelial and stromal cells prepared from menstrual endometrium in patients with endometriosis compared to patients without endometriosis. Treatment with PKF 115-584 inhibited MMP-9 activity to undetectable levels in both menstrual endometrial epithelial and stromal cells of patients with endometriosis. The number of invasive cells was significantly higher in epithelial and stromal cells of endometriotic tissue compared with matched eutopic endometrium of the same patients. Treatment with PKF 115-584 decreased the number of invasive endometriotic epithelial cells by 73

Wnt/β-Catenin Signaling Activation beyond Robust Nuclear β-Catenin Accumulation in Nondysplastic Barrett’s Esophagus: Regulation via Dickkopf-1

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Orestis Lyros

2015-07-01

Full Text Available INTRODUCTION: Wnt/β-catenin signaling activation has been reported only during the late steps of Barrett’s esophagus (BE neoplastic progression, but not in BE metaplasia, based on the absence of nuclear β-catenin. However, β-catenin transcriptional activity has been recorded in absence of robust nuclear accumulation. Thus, we aimed to investigate the Wnt/β-catenin signaling in nondysplastic BE. METHODS: Esophageal tissues from healthy and BE patients without dysplasia were analyzed for Wnt target gene expression by quantitative reverse transcription polymerase chain reaction (qRT-PCR and immunohistochemistry. Esophageal squamous (EPC1-& EPC2-hTERT, BE metaplastic (CP-A, and adenocarcinoma (OE33 cell lines were characterized for Wnt activation by qRT-PCR, Western blot, and luciferase assay. Wnt activity regulation was examined by using recombinant Wnt3a and Dickkopf-1 (Dkk1 as well as Dkk1 short interfering RNA. RESULTS: Wnt target genes (AXIN2, c-MYC, Cyclin D1, Dkk1 and Wnt3a were significantly upregulated in nondysplastic BE compared with squamous mucosa. Elevated levels of dephosphorylated β-catenin were detected in nondysplastic BE. Nuclear active β-catenin and TOPflash activity were increased in CP-A and OE33 cells compared with squamous cells. Wnt3a-mediated β-catenin signaling activation was abolished by Dkk1 in CP-A cells. TOPFlash activity was elevated following Dkk1 silencing in CP-A but not in OE33 cells. Dysplastic and esophageal adenocarcinoma tissues demonstrated further Dkk1 and AXIN2 overexpression. CONCLUSIONS: Despite the absence of robust nuclear accumulation, β-catenin is transcriptionally active in nondysplastic BE. Dkk1 overexpression regulates β-catenin signaling in BE metaplastic but not in adenocarcinoma cells, suggesting that early perturbation of Dkk1-mediated signaling suppression may contribute to BE malignant transformation.

Frizzled 7 expression is positively regulated by SIRT1 and β-catenin in breast cancer cells.

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Glenn E Simmons

Full Text Available The Wnt signaling pathway is often chronically activated in diverse human tumors, and the Frizzled (FZD family of receptors for Wnt ligands, are central to propagating oncogenic signals in a β-catenin-dependent and independent manner. SIRT1 is a class III histone deacetylase (HDAC that deacetylates histone and non-histone proteins to regulate gene transcription and protein function. We previously demonstrated that SIRT1 loss of function led to a significant decrease in the levels of Dishevelled (Dvl proteins. To further explore this connection between the sirtuins and components of the Wnt pathway, we analyzed sirtuin-mediated regulation of FZD proteins. Here we explore the contribution of sirtuin deacetylases in promoting constitutive Wnt pathway activation in breast cancer cells. We demonstrate that the use of small molecule inhibitors of SIRT1 and SIRT2, and siRNA specific to SIRT1, all reduce the levels of FZD7 mRNA. We further demonstrate that pharmacologic inhibition of SIRT1/2 causes a marked reduction in FZD7 protein levels. Additionally, we show that β-catenin and c-Jun occupy the 7 kb region upstream of the transcription start site of the FZD7 gene, and SIRT1 inhibition leads to a reduction in the occupancy of both β-catenin and c-Jun at points along this region. This work uncovers a new mechanism for the regulation of FZD7 and provides a critical new link between the sirtuins and FZD7, one of the earliest nodal points from which oncogenic Wnt signaling emanates. This study shows that inhibition of specific sirtuins may provide a unique strategy for inhibiting the constitutively active Wnt pathway at the level of the receptor.

[Inhibitory effect of Biejiajian pills on HepG2 cell xenograft growth and expression of β-catenin and Tbx3 in nude mice].

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Wen, Bin; Sun, Hai-Tao; He, Song-Qi; LA, Lei; An, Hai-Yan; Pang, Jie

2016-02-01

To explore the molecular mechanism by which Biejiajian pills inhibit hepatocellular carcinoma in a nude mouse model bearing HepG2 cell xenograft. The inhibitory effect of Biejiajian pills on the growth of HepG2 cell xenograft in nude mice was observed. Immunohistochemical method was used to examine proliferating cell nuclear antigen (PCNA) expression in HepG2 cell xenograft, and TUNEL method was employed to detect the cell apoptosis; the expression levels of β-catenin and Tbx3 were measured by Western blotting. Biejiajian pills significantly suppressed the growth of HepG2 cell xenograft in nude mice. The tumor-bearing mice treated with a high and a moderate dose of Biejiajian pills showed significantly increased apoptosis rate of the tumor cells [(22.9±1.220)% and (14.7±0.50)%, respectively] compared with the control group [(5.5±0.90)%, Ppills significantly decreased the expressions of PNCA, β-catenin, and Tbx3 in the cell xenograft (Ppills can inhibit the growth of HepG2 cell xenograft in nude mice and promote tumor cell apoptosis possibly by inhibiting PNCA expression and the Wnt/β-catenin signaling pathway.

Linc00210 drives Wnt/β-catenin signaling activation and liver tumor progression through CTNNBIP1-dependent manner.

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Fu, Xiaomin; Zhu, Xiaoyan; Qin, Fujun; Zhang, Yong; Lin, Jizhen; Ding, Yuechao; Yang, Zihe; Shang, Yiman; Wang, Li; Zhang, Qinxian; Gao, Quanli

2018-03-14

Liver tumor initiating cells (TICs) have self-renewal and differentiation properties, accounting for tumor initiation, metastasis and drug resistance. Long noncoding RNAs are involved in many physiological and pathological processes, including tumorigenesis. DNA copy number alterations (CNA) participate in tumor formation and progression, while the CNA of lncRNAs and their roles are largely unknown. LncRNA CNA was determined by microarray analyses, realtime PCR and DNA FISH. Liver TICs were enriched by surface marker CD133 and oncosphere formation. TIC self-renewal was analyzed by oncosphere formation, tumor initiation and propagation. CRISPRi and ASO were used for lncRNA loss of function. RNA pulldown, western blot and double FISH were used to identify the interaction between lncRNA and CTNNBIP1. Using transcriptome microarray analysis, we identified a frequently amplified long noncoding RNA in liver cancer termed linc00210, which was highly expressed in liver cancer and liver TICs. Linc00210 copy number gain is associated with its high expression in liver cancer and liver TICs. Linc00210 promoted self-renewal and tumor initiating capacity of liver TICs through Wnt/β-catenin signaling. Linc00210 interacted with CTNNBIP1 and blocked its inhibitory role in Wnt/β-catenin activation. Linc00210 silencing cells showed enhanced interaction of β-catenin and CTNNBIP1, and impaired interaction of β-catenin and TCF/LEF components. We also confirmed linc00210 copy number gain using primary hepatocellular carcinoma (HCC) samples, and found the correlation between linc00210 CNA and Wnt/β-catenin activation. Of interest, linc00210, CTNNBIP1 and Wnt/β-catenin signaling targeting can efficiently inhibit tumor growth and progression, and liver TIC propagation. With copy-number gain in liver TICs, linc00210 is highly expressed along with liver tumorigenesis. Linc00210 drives the self-renewal and propagation of liver TICs through activating Wnt/β-catenin signaling. Linc00210

[Effects of Biejiajian Pills on Wnt signal pathway signal molecules β-catenin/TCF4 complex activities and downstream proteins cyclin D1 and MMP-2 in hepatocellular carcinoma cells].

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Wen, Bin; Sun, Haitao; He, Songqi; Cheng, Yang; Jia, Wenyan; Fan, Eryan; Pang, Jie

2014-12-01

To study the effect of Biejiajian Pills on Wnt signal pathway and the mechanisms underlying its action to suppress the invasiveness of hepatocellular carcinoma. HepG2 cells cultured in the serum of rats fed with Biejiajian Pills for 48 h were examined for β-catenin expression using immunofluorescence, β-catenin/TCF4 complex activity with luciferase, and expressions of the downstream proteins cyclin D1 and MMP-2 using qRT-PCR. Biejiajian Pills-treated sera significantly reduced the expressions of cytoplasmic and nuclear β-catenin protein, cyclin D1 and MMP-2 proteins and lowered the activities of β-catenin/TCF4 complex. Biejiajian Pills may serve as a potential anti-tumor agent, whose effect might be mediated by inhibiting the Wnt/β-catenin pathway.

Methylprednisolone promotes recovery of neurological function after spinal cord injury: association with Wnt/β-catenin signaling pathway activation

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Lu, Gong-biao; Niu, Fu-wen; Zhang, Ying-chun; Du, Lin; Liang, Zhi-yuan; Gao, Yuan; Yan, Ting-zhen; Nie, Zhi-kui; Gao, Kai

2016-01-01

Some studies have indicated that the Wnt/β-catenin signaling pathway is activated following spinal cord injury, and expression levels of specific proteins, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β, are significantly altered. We hypothesized that methylprednisolone treatment contributes to functional recovery after spinal cord injury by inhibiting apoptosis and activating the Wnt/β-catenin signaling pathway. In the current study, 30 mg/kg methylprednisolone was injected into rats with spinal cord injury immediately post-injury and at 1 and 2 days post-injury. Basso, Beattie, and Bresnahan scores showed that methylprednisolone treatment significantly promoted locomotor functional recovery between 2 and 6 weeks post-injury. The number of surviving motor neurons increased, whereas the lesion size significantly decreased following methylprednisolone treatment at 7 days post-injury. Additionally, caspase-3, caspase-9, and Bax protein expression levels and the number of apoptotic cells were reduced at 3 and 7 days post-injury, while Bcl-2 levels at 7 days post-injury were higher in methylprednisolone-treated rats compared with saline-treated rats. At 3 and 7 days post-injury, methylprednisolone up-regulated expression and activation of the Wnt/β-catenin signaling pathway, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β phosphorylation. These results indicate that methylprednisolone-induced neuroprotection may correlate with activation of the Wnt/β-catenin signaling pathway. PMID:28123427

USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination

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Laura Novellasdemunt

2017-10-01

Full Text Available The tumor suppressor gene adenomatous polyposis coli (APC is mutated in most colorectal cancers (CRCs, resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs.

Trichostatin A inhibits beta-casein expression in mammary epithelial cells

International Nuclear Information System (INIS)

Pujuguet, Philippe; Radisky, Derek; Levy, Dinah; Lacza, Charlemagne; Bissell, Mina J.

2002-01-01

Many aspects of cellular behavior are affected by information derived from association of the extracellular matrix (ECM) and with cell membrane receptors. When cultured in the presence of laminin-containing ECM and prolactin (Prl), normal mammary epithelial cells express the milk protein beta-casein. Previously, we defined the minimal ECM- and Prl-responsive enhancer element BCE-1 from the upstream region of the beta-casein gene. We also found that BCE-1 was only active when stably integrated into chromatin, and that trichostatin A (TSA), a reagent that leads to alterations in chromatin structure, was able to activate the integrated enhancer element. We now show that endogenous b-casein gene, which is controlled by a genetic assembly that is highly similar to that of BCE-1 and which is also activated by incubation in ECM and Prl, is instead inhibited by TSA. We provide evidence that the differing response of b-casein and BCE-1 to TSA is neither due to an unusual effect of TSA on mammary epithelial cells, nor to secondary consequences from the expression of a separate gene, nor to a particular property of the BCE-1 construct. As a component of this investigation, we also showed that ECM could mediate rapid histone deacetylation in mammary epithelial cells. These results are discussed in combination with previous work showing that TSA mediates the differentiation of many types of cancer cells but inhibits differentiation of some nonmalignant cell types

beta-TrCP inhibition reduces prostate cancer cell growth via upregulation of the aryl hydrocarbon receptor.

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Udi Gluschnaider

2010-02-01

Full Text Available Prostate cancer is a common and heterogeneous disease, where androgen receptor (AR signaling plays a pivotal role in development and progression. The initial treatment for advanced prostate cancer is suppression of androgen signaling. Later on, essentially all patients develop an androgen independent stage which does not respond to anti hormonal treatment. Thus, alternative strategies targeting novel molecular mechanisms are required. beta-TrCP is an E3 ligase that targets various substrates essential for many aspects of tumorigenesis.Here we show that beta-TrCP depletion suppresses prostate cancer and identify a relevant growth control mechanism. shRNA targeted against beta-TrCP reduced prostate cancer cell growth and cooperated with androgen ablation in vitro and in vivo. We found that beta-TrCP inhibition leads to upregulation of the aryl hydrocarbon receptor (AhR mediating the therapeutic effect. This phenomenon could be ligand independent, as the AhR ligand 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD did not alter prostate cancer cell growth. We detected high AhR expression and activation in basal cells and atrophic epithelial cells of human cancer bearing prostates. AhR expression and activation is also significantly higher in tumor cells compared to benign glandular epithelium.Together these observations suggest that AhR activation may be a cancer counteracting mechanism in the prostate. We maintain that combining beta-TrCP inhibition with androgen ablation could benefit advanced prostate cancer patients.

Beta Catenin in Prostate Cancer Apoptosis

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2014-04-01

independent of AR expression. In addition, TRAIL-TZD antagonizes GSK3β and GSK3α pathways in these cells via up-regulating pGSK3βSer9 levels (indicating...and TZD on inhibiting total GSK3β expression: To determine the optimal concentration of TRAIL and TZD required for reducing GSK3β and GSK3α ...or TRAIL. The results indicated that 50-100µM TZD when combined with 100ng/ml TRAIL is optimal for maximal reduction of both GSK3β and GSK3α

Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.

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Gibbs, Marie E; Hutchinson, Dana S; Summers, Roger J

2008-09-01

Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.

CD147 modulates androgen receptor activity through the Akt/Gsk-3β/β-catenin/AR pathway in prostate cancer cells.

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Fang, Fang; Qin, Yingxin; Hao, Feng; Li, Qiang; Zhang, Wei; Zhao, Chen; Chen, Shuang; Zhao, Liangzhong; Wang, Liguo; Cai, Jianhui

2016-08-01

The androgen signaling pathway serves an important role in the development of prostate cancer. β-Catenin is an androgen receptor (AR) cofactor and augments AR signaling. Glycogen synthase kinase-3β (GSK-3β), a target of phosphorylated serine/threonine protein kinase B (p-Akt), regulates β-catenin stability. In addition, β-catenin, a coregulator of AR, physically interacts with AR and enhances AR-mediated target gene transcription. The multifunctional glycoprotein cluster of differentiation (CD) 147 is highly expressed on the cell surface of the majority of cancer cells, and it promotes tumor invasion, metastasis and growth. In the present study, the molecular effects of CD147 on the Akt/GSK-3β/β-catenin/AR signaling network were investigated in LNCaP cells. Using short hairpin-mediated RNA knockdown of CD147 in LNCaP cells, it was demonstrated that downregulation of CD147 resulted in inhibitory phosphorylation of GSK-3β, and then promoted degeneration of β-catenin and reduced nuclear accumulation of β-catenin. In addition, immunoprecipitation studies demonstrated that CD147 downregulation decreased the formation of a complex between β-catenin and AR. It was shown that CD147 knockdown suppressed the expression of the AR target gene prostate-specific antigen and the growth of AR-positive LNCaP cells. Furthermore, inhibition of PI3K/Akt with LY294002 augmented CD147-mediated function. The present study indicates that the PI3K/Akt pathway may facilitate CD147-mediated activation of the AR pathway.

Social Isolation Modulates CLOCK Protein and Beta-Catenin Expression Pattern in Gonadotropin-Inhibitory Hormone Neurons in Male Rats.

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Teo, Chuin Hau; Soga, Tomoko; Parhar, Ishwar S

2017-01-01

Postweaning social isolation reduces the amplitude of the daily variation of CLOCK protein in the brain and induces lower reproductive activity. Gonadotropin-inhibitory hormone (GnIH) acts as an inhibitor in the reproductive system and has been linked to stress. Social isolation has been shown to lower neuronal activity of GnIH-expressing neurons in the dorsomedial hypothalamus (DMH). The exact mechanism by which social isolation may affect GnIH is still unclear. We investigated the impact of social isolation on regulatory cellular mechanisms in GnIH neurons. We examined via immunohistochemistry the expression of CLOCK protein at four different times throughout the day in GnIH cells tagged with enhanced fluorescent green protein (EGFP-GnIH) in 9-week-old adult male rats that have been raised for 6 weeks under postweaning social isolation and compared them with group-raised control rats of the same age. We also studied the expression of β-catenin-which has been shown to be affected by circadian proteins such as Bmal1-in EGFP-GnIH neurons to determine whether it could play a role in linking CLOCK in GnIH neurons. We found that social isolation modifies the pattern of CLOCK expression in GnIH neurons in the DMH. Socially isolated rats displayed greater CLOCK expression in the dark phase, while control rats displayed increased CLOCK expression in the light phase. Furthermore, β-catenin expression pattern in GnIH cells was disrupted by social isolation. This suggests that social isolation triggers changes in CLOCK and GnIH expression, which may be associated with an increase in nuclear β-catenin during the dark phase.

MicroRNA-200a suppresses the Wnt/?-catenin signaling pathway by interacting with ?-catenin

OpenAIRE

SU, JUAN; ZHANG, ANLING; SHI, ZHENDONG; MA, FEIFEI; PU, PEIYU; WANG, TAO; ZHANG, JIE; KANG, CHUNSHENG; ZHANG, QINGYU

2011-01-01

The Wnt/?-catenin signaling pathway is crucial for human organ development and is involved in tumor progression of many cancers. Accumulating evidence suggests that the expression of ?-catenin is, in part, regulated by specific microRNAs (miRNAs). The purpose of this study was to determine the expression of a recently identified epithelial to mesenchymal transition (EMT)-associated tumor suppressor microRNA (miR)-200a, in cancer cells. We also aimed to identify specific miR-200a target genes ...

Novel synthetic antagonists of canonical Wnt signaling inhibit colorectal cancer cell growth

Czech Academy of Sciences Publication Activity Database

Waaler, J.; Machoň, Ondřej; von Kries, J.P.; Wilson, S.R.; Lundenes, E.; Wedlich, D.; Gradl, D.; Paulsen, J.E.; Machoňová, O.; Dembinski, J.L.; Dinh, H.; Krauss, S.

2011-01-01

Roč. 71, č. 1 (2011), s. 197-205 ISSN 0008-5472 Institutional research plan: CEZ:AV0Z50520514 Keywords : beta catenin * cyclooxygenase-2 inhibitor * transcription Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.856, year: 2011

HIV-1 gp120 Upregulates Brain-Derived Neurotrophic Factor (BDNF) Expression in BV2 Cells via the Wnt/β-Catenin Signaling Pathway.

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Wang, Yongdi; Liao, Jinxu; Tang, Shao-Jun; Shu, Jianhong; Zhang, Wenping

2017-06-01

HIV-1 gp120 plays a critical role in the pathogenesis of HIV-associated pain, but the underlying molecular mechanisms are incompletely understood. This study aims to determine the effect and possible mechanism of HIV-1 gp120 on BDNF expression in BV2 cells (a murine-derived microglial cell line). We observed that gp120 (10 ng/ml) activated BV2 cells in cultures and upregulated proBDNF/mBDNF. Furthermore, gp120-treated BV2 also accumulated Wnt3a and β-catenin, suggesting the activation of the Wnt/β-catenin pathway. We demonstrated that activation of the pathway by Wnt3a upregulated BDNF expression. In contrast, inhibition of the Wnt/β-catenin pathway by either DKK1 or IWR-1 attenuated BDNF upregulation induced by gp120 or Wnt3a. These findings collectively suggest that gp120 stimulates BDNF expression in BV2 cells via the Wnt/β-catenin signaling pathway.

Lanatoside C inhibits cell proliferation and induces apoptosis through attenuating Wnt/β-catenin/c-Myc signaling pathway in human gastric cancer cell.

Science.gov (United States)

Hu, Yudong; Yu, Kaikai; Wang, Gang; Zhang, Depeng; Shi, Chaoji; Ding, Yunhe; Hong, Duo; Zhang, Dan; He, Huiqiong; Sun, Lei; Zheng, Jun-Nian; Sun, Shuyang; Qian, Feng

2018-04-01

Gastric cancer is the third common cause of cancer mortality in the world with poor prognosis and high recurrence due to lack of effective medicines. Our studies revealed that lanatoside C, a FDA-approved cardiac glycoside, had an anti-proliferation effect on different human cancer cell lines (MKN-45; SGC-7901; HN4; MCF-7; HepG2) and gastric cell lines MKN-45 and SGC-7901 were the most sensitive cell lines to lanatoside C. MKN-45 cells treated with lanatoside C showed cell cycle arrest at G2/M phase and inhibition of cell migration. Meanwhile, upregulation of cleaved caspase-9 and cleaved PARP and downregulation of Bcl-xl were accompanied with the loss of mitochondrial membrane potential (MMP) and induction of intracellular reactive oxygen species (ROS). Lanatoside C inhibited Wnt/β-catenin signaling with downregulation of c-Myc, while overexpression of c-Myc reversed the anti-tumor effect of lanatoside C, confirming that c-Myc is a key drug target of lanatoside C. Furthermore, we discovered that lanatoside C prompted c-Myc degradation in proteasome-ubiquitin pathway with attenuating the binding of USP28 to c-Myc. These findings indicate that lanatoside C targeted c-Myc ubiquitination to inhibit MKN-45 proliferation and support the potential value of lanatoside C as a chemotherapeutic candidate. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

Science.gov (United States)

Su, Tzu-Rong; Lin, Jen-Jie; Tsai, Chi-Chu; Huang, Tsu-Kei; Yang, Zih-Yan; Wu, Ming-O; Zheng, Yu-Qing; Su, Ching-Chyuan; Wu, Yu-Jen

2013-01-01

Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP1), and dopachrome tautomerase (Dct). In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK). Using inhibitors against PI3K/Akt (LY294002) or MEK/ERK-specific (PD98059), the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763) restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions. PMID:24129178

Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

Directory of Open Access Journals (Sweden)

Yu-Jen Wu

2013-10-01

Full Text Available Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP1, and dopachrome tautomerase (Dct. In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK/extracellular signal-regulated kinase (ERK. Using inhibitors against PI3K/Akt (LY294002 or MEK/ERK-specific (PD98059, the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763 restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

Mesd Is a Universal Inhibitor of Wnt Co-receptor LRP5/6 and Blocks Wnt/β-catenin Signaling in Cancer Cells†

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Lu, Wenyan; Liu, Chia-Chen; Thottassery, Jaideep V.; Bu, Guojun; Li, Yonghe

2010-01-01

Mesd is a specialized chaperone for the low-density lipoprotein receptor-related protein-5 (LRP5) and LRP6. In our previous studies, we found that Mesd binds to mature LRP6 on the cell surface and blocks the binding of Wnt antagonist Dickkopf-1(Dkk1) to LRP6. Herein, we demonstrated that Mesd also binds to LRP5 with a high affinity, and is a universal inhibitor of LRP5/6 ligands. Mesd not only blocks Wnt antagonists Dkk1 and Sclerostin binding to LRP5/6, but also inhibits Wnt3A and Rspondin1-induced Wnt/β-catenin signaling in LRP5/6 expressing cells. We also found that Mesd, Dkk1 and Sclerostin compete with one another for binding to LRP5 and LRP6 at the cell surface. More importantly, we demonstrated that Mesd is able to suppress LRP6 phosphorylation and Wnt/β-catenin signaling in prostate cancer PC-3 cells, and inhibits PC-3 cell proliferation. Our results indicate that recombinant Mesd protein is a useful tool for studying Wnt/β-catenin signaling on the cell surface, and has a potential therapeutic role in Wnt-dependent cancers. PMID:20446724

Probing transcription-specific outputs of β-catenin in vivo.

Science.gov (United States)

Valenta, Tomas; Gay, Max; Steiner, Sarah; Draganova, Kalina; Zemke, Martina; Hoffmans, Raymond; Cinelli, Paolo; Aguet, Michel; Sommer, Lukas; Basler, Konrad

2011-12-15

β-Catenin, apart from playing a cell-adhesive role, is a key nuclear effector of Wnt signaling. Based on activity assays in Drosophila, we generated mouse strains where the endogenous β-catenin protein is replaced by mutant forms, which retain the cell adhesion function but lack either or both of the N- and the C-terminal transcriptional outputs. The C-terminal activity is essential for mesoderm formation and proper gastrulation, whereas N-terminal outputs are required later during embryonic development. By combining the double-mutant β-catenin with a conditional null allele and a Wnt1-Cre driver, we probed the role of Wnt/β-catenin signaling in dorsal neural tube development. While loss of β-catenin protein in the neural tube results in severe cell adhesion defects, the morphology of cells and tissues expressing the double-mutant form is normal. Surprisingly, Wnt/β-catenin signaling activity only moderately regulates cell proliferation, but is crucial for maintaining neural progenitor identity and for neuronal differentiation in the dorsal spinal cord. Our model animals thus allow dissecting signaling and structural functions of β-catenin in vivo and provide the first genetic tool to generate cells and tissues that entirely and exclusively lack canonical Wnt pathway activity. © 2011 by Cold Spring Harbor Laboratory Press

Full Length Research Paper Curcumin induces cleavage of -catenin ...

African Journals Online (AJOL)

β-Catenin/Tcf-4 signaling pathway plays important roles in colorectal tumorigenesis. RT-PCR, western blotting and immunoprecipitation were used to study the effects of curcumin on β-catenin/Tcf-4 signaling pathway in HT-29 cells. Treatment of curcumin could induce cleavage of β-catenin and the cleavage could be ...

Inhibition of canonical WNT signaling pathway by β-catenin/CBP inhibitor ICG-001 ameliorates liver fibrosis in vivo through suppression of stromal CXCL12.

Science.gov (United States)

Akcora, Büsra Öztürk; Storm, Gert; Bansal, Ruchi

2018-03-01

Quiescent hepatic stellate cells (HSCs), in response to liver injury, undergo characteristic morphological transformation into proliferative, contractile and ECM-producing myofibroblasts. In this study, we investigated the implication of canonical Wnt signaling pathway in HSCs and liver fibrogenesis. Canonical Wnt signaling pathway activation and inhibition using β-catenin/CBP inhibitor ICG001 was examined in-vitro in TGFβ-activated 3T3, LX2, primary human HSCs, and in-vivo in CCl 4 -induced acute liver injury mouse model. Fibroblasts-conditioned medium studies were performed to assess the Wnt-regulated paracrine factors involved in crosstalk between HSCs-macrophages and HSCs-endothelial cells. Canonical Wnt signaling pathway components were significantly up-regulated in-vitro and in-vivo. In-vitro, ICG-001 significantly inhibited fibrotic parameters, 3D-collagen contractility and wound healing. Conditioned medium induced fibroblasts-mediated macrophage and endothelial cells activation was significantly inhibited by ICG-001. In-vivo, ICG-001 significantly attenuated collagen accumulation and HSC activation. Interestingly, ICG-001 drastically inhibited macrophage infiltration, intrahepatic inflammation and angiogenesis. We further analyzed the paracrine factors involved in Wnt-mediated effects and found CXCL12 was significantly suppressed both in-vitro and in-vivo following Wnt inhibition. Wnt-regulated CXCL12 secretion from activated HSCs potentiated macrophage infiltration and activation, and angiogenesis. Pharmacological inhibition of canonical Wnt signaling pathway via suppression of stromal CXCL12 suggests a potential therapeutic approach targeting activated HSCs in liver fibrosis. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Salinomycin inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cell in vitro and suppresses tumor growth in vivo

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Wu, Danxin; Zhang, Yu; Huang, Jie; Fan, Zirong; Shi, Fengrong; Wang, Senming, E-mail: wsenming@126.com

2014-01-10

Highlight: •We first evaluated the effect of salinomycin on nasopharyngeal carcinoma (NPC). •Salinomycin could inhibit Wnt/β-catenin signaling and induce apoptosis in NPC. •So salinomycin may be a good potential candidate for the chemotherapy of NPC. -- Abstract: Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.

Wogonin induced G1 cell cycle arrest by regulating Wnt/β-catenin signaling pathway and inactivating CDK8 in human colorectal cancer carcinoma cells

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He, Licheng; Lu, Na; Dai, Qinsheng; Zhao, Yue; Zhao, Li; Wang, Hu; Li, Zhiyu; You, Qidong; Guo, Qinglong

2013-01-01

Highlights: • Wogonin inhibited HCT116 cells growth and arrested at G1 phase of the cell cycle. • Wogonin down-regulated the canonical Wnt/β-catenin signaling pathway. • Wogonin interfered in the combination of β-catenin and TCF/Lef. • Wogonin limited the kinase activity of CDK8. - Abstract: Wogonin, a naturally occurring mono-flavonoid, has been reported to have tumor therapeutic potential and good selectivity both in vitro and in vivo. Herein, we investigated the anti-proliferation effects and associated mechanisms of wogonin in human colorectal cancer in vitro. The flow-cytometric analysis showed that wogonin induced a G1 phase cell cycle arrest in HCT116 cells in a concentration- and time-dependent manner. Meanwhile, the cell cycle-related proteins, such as cyclin A, E, D1, and CDK2, 4 were down-regulated in wogonin-induced G1 cell cycle arrest. Furthermore, we showed that the anti-proliferation and G1 arrest effect of wogonin on HCT116 cells was associated with deregulation of Wnt/β-catenin signaling pathway. Wogonin-treated cells showed decreased intracellular levels of Wnt proteins, and activated degradation complex to phosphorylated and targeted β-catenin for proteasomal degradation. Wogonin inhibited β-catenin-mediated transcription by interfering in the transcriptional activity of TCF/Lef, and repressing the kinase activity of CDK8 which has been considered as an oncogene involving in the development of colorectal cancers. Moreover, CDK8 siRNA-transfected HCT116 cells showed similar results to wogonin treated cells. Thus, our data suggested that wogonin induced anti-proliferation and G1 arrest via Wnt/β-catenin signaling pathway and it can be developed as a therapeutic agent against human colorectal cancer

Activation of β-catenin signaling in androgen receptor-negative prostate cancer cells.

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Wan, Xinhai; Liu, Jie; Lu, Jing-Fang; Tzelepi, Vassiliki; Yang, Jun; Starbuck, Michael W; Diao, Lixia; Wang, Jing; Efstathiou, Eleni; Vazquez, Elba S; Troncoso, Patricia; Maity, Sankar N; Navone, Nora M

2012-02-01

To study Wnt/β-catenin in castrate-resistant prostate cancer (CRPC) and understand its function independently of the β-catenin-androgen receptor (AR) interaction. We carried out β-catenin immunocytochemical analysis, evaluated TOP-flash reporter activity (a reporter of β-catenin-mediated transcription), and sequenced the β-catenin gene in MDA prostate cancer 118a, MDA prostate cancer 118b, MDA prostate cancer 2b, and PC-3 prostate cancer cells. We knocked down β-catenin in AR-negative MDA prostate cancer 118b cells and carried out comparative gene-array analysis. We also immunohistochemically analyzed β-catenin and AR in 27 bone metastases of human CRPCs. β-Catenin nuclear accumulation and TOP-flash reporter activity were high in MDA prostate cancer 118b but not in MDA prostate cancer 2b or PC-3 cells. MDA prostate cancer 118a and MDA prostate cancer 118b cells carry a mutated β-catenin at codon 32 (D32G). Ten genes were expressed differently (false discovery rate, 0.05) in MDA prostate cancer 118b cells with downregulated β-catenin. One such gene, hyaluronan synthase 2 (HAS2), synthesizes hyaluronan, a core component of the extracellular matrix. We confirmed HAS2 upregulation in PC-3 cells transfected with D32G-mutant β-catenin. Finally, we found nuclear localization of β-catenin in 10 of 27 human tissue specimens; this localization was inversely associated with AR expression (P = 0.056, Fisher's exact test), suggesting that reduced AR expression enables Wnt/β-catenin signaling. We identified a previously unknown downstream target of β-catenin, HAS2, in prostate cancer, and found that high β-catenin nuclear localization and low or no AR expression may define a subpopulation of men with bone metastatic prostate cancer. These findings may guide physicians in managing these patients.

Heterocellular interaction enhances recruitment of α and β-catenins and ZO-2 into functional gap-junction complexes and induces gap junction-dependant differentiation of mammary epithelial cells

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Talhouk, Rabih S.; Mroue, Rana; Mokalled, Mayssa; Abi-Mosleh, Lina; Nehme, Ralda; Ismail, Ayman; Khalil, Antoine; Zaatari, Mira; El-Sabban, Marwan E.

2008-01-01

Gap junctions (GJ) are required for mammary epithelial differentiation. Using epithelial (SCp2) and myoepithelial-like (SCg6) mouse-derived mammary cells, the role of heterocellular interaction in assembly of GJ complexes and functional differentiation (β-casein expression) was evaluated. Heterocellular interaction is critical for β-casein expression, independent of exogenous basement membrane or cell anchoring substrata. Functional differentiation of SCp2, co-cultured with SCg6, is more sensitive to GJ inhibition relative to homocellular SCp2 cultures differentiated by exogenous basement membrane. Connexin (Cx)32 and Cx43 levels were not regulated across culture conditions; however, GJ functionality was enhanced under differentiation-permissive conditions. Immunoprecipitation studies demonstrated association of junctional complex components (α-catenin, β-catenin and ZO-2) with Cx32 and Cx43, in differentiation conditions, and additionally with Cx30 in heterocellular cultures. Although β-catenin did not shuttle between cadherin and GJ complexes, increased association between connexins and β-catenin in heterocellular cultures was observed. This was concomitant with reduced nuclear β-catenin, suggesting that differentiation in heterocellular cultures involves sequestration of β-catenin in GJ complexes

EZH2 Impairs Human Dental Pulp Cell Mineralization via the Wnt/β-Catenin Pathway.

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Li, B; Yu, F; Wu, F; Hui, T; A, P; Liao, X; Yin, B; Wang, C; Ye, L

2018-05-01

The enhancer of zeste homolog 2 (EZH2) is a catalytic subunit of PRC2 (polycomb repressor complex 2). It mediates gene silencing via methyltransferase activity and is involved in the determination of cell lineage. However, the function of EZH2 and the underlying mechanisms by which it affects the differentiation of human dental pulp cell (hDPC) have remained underexplored. In this research, we found that EZH2 expression decreased during the mineralization of hDPCs, with attenuated H3K27me3 (trimethylation on lysine 27 in histone H3). Overexpression of EZH2 impaired the odontogenic differentiation of hDPCs, while EZH2 without methyltransferase activity mutation (mutation of suppressed variegation of 3 to 9, enhancer of zeste and trithorax domain, EZH2ΔSET) did not display this phenotype. In addition, siRNA knockdown studies showed that EZH2 negatively modulated hDPC differentiation in vitro and inhibited mineralized nodule formation in transplanted β-tricalcium phosphate / hDPC composites. To further investigate the underlying mechanisms, we explored the Wnt/β-catenin signaling pathway in view of the fact that previous research had documented the essential role that it plays during hDPC mineralization, as well as its links to EZH2 in other cells. We demonstrated for the first time that EZH2 depletion activated the Wnt/β-catenin signaling pathway and enhanced the accumulation of β-catenin in hDPCs. Chromatin immunoprecipitation analysis suggested that these effects are attributable to the level of the EZH2-regulated H3K27me3 on the β-catenin promoter. We conclude that EZH2 plays a negative role during the odontogenic differentiation of hDPCs. Suppression of EZH2 could promote hDPC mineralization by epigenetically regulating the expression of β-catenin and activating the Wnt canonical signaling pathway.

β-catenin/Wnt signaling controls progenitor fate in the developing and regenerating zebrafish retina

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Meyers Jason R

2012-08-01

Full Text Available Abstract Background The zebrafish retina maintains two populations of stem cells: first, the germinal zone or ciliary marginal zone (CMZ contains multipotent retinal progenitors that add cells to the retinal periphery as the fish continue to grow; second, radial glia (Müller cells occasionally divide asymmetrically to generate committed progenitors that differentiate into rod photoreceptors, which are added interstitially throughout the retina with growth. Retinal injury stimulates Müller glia to dedifferentiate, re-enter the cell cycle, and generate multipotent retinal progenitors similar to those in the CMZ to replace missing neurons. The specific signals that maintain these two distinct populations of endogenous retinal stem cells are not understood. Results We used genetic and pharmacological manipulation of the β-catenin/Wnt signaling pathway to show that it is required to maintain proliferation in the CMZ and that hyperstimulation of β-catenin/Wnt signaling inhibits normal retinal differentiation and expands the population of proliferative retinal progenitors. To test whether similar effects occur during regeneration, we developed a method for making rapid, selective photoreceptor ablations in larval zebrafish with intense light. We found that dephosphorylated β-catenin accumulates in Müller glia as they re-enter the cell cycle following injury, but not in Müller glia that remain quiescent. Activation of Wnt signaling is required for regenerative proliferation, and hyperstimulation results in loss of Müller glia from the INL as all proliferative cells move into the ONL. Conclusions β-catenin/Wnt signaling is thus required for the maintenance of retinal progenitors during both initial development and lesion-induced regeneration, and is sufficient to prevent differentiation of those progenitors and maintain them in a proliferative state. This suggests that the β-catenin/Wnt cascade is part of the shared molecular circuitry that

miR-612 suppresses the stemness of liver cancer via Wnt/β-catenin signaling

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Tang, Jun [Liver Cancer Institute and Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032 (China); Tao, Zhong-Hua [Department of Medical Oncology, Shanghai Cancer Center, Fudan University, Shanghai 200032 (China); Wen, Duo; Wan, Jin-Liang; Liu, Dong-Li; Zhang, Shu; Cui, Jie-Feng; Sun, Hui-Chuan; Wang, Lu [Liver Cancer Institute and Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032 (China); Zhou, Jian; Fan, Jia [Liver Cancer Institute and Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032 (China); Institute of Biomedical Sciences of Fudan University, Shanghai 200032 (China); Wu, Wei-Zhong, E-mail: wu.weizhong@zs-hospital.sh.cn [Liver Cancer Institute and Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032 (China)

2014-04-25

Highlights: • miR-612 suppresses tumorsphere and clone formation of HCC cells. • miR-612 reduces drug resistance of HCC cells. • miR-612 suppresses tumorigenesis of HCC in NOD/SCID mice. • miR-612 inhibits an invasive frontier of HCC xenografts. • miR-612 suppresses Wnt/β-catenin signaling. - Abstract: Previous research showed that microRNA-612 (miR-612) has inhibitory effects on cell proliferation, migration, invasion, and metastasis of hepatocellular carcinoma (HCC). AKT2 was confirmed to be a direct target of miR-612, through which the epithelial–mesenchymal transition (EMT) and metastasis of HCC were inhibited. Our present findings reveal that miR-612 is able to suppress the stemness of HCC by reducing the number and size of tumorspheres as well as clone formation in soft agar, and to relieve drug resistance to cisplatin and 5-fluorouracil. In addition, miR-612 hampered the capacity of tumorigenesis in NOD/SCID mice and redistributed the tumor invasive frontier of miR-612-modulating cells. Finally, our findings suggest that Wnt/β-catenin signaling is required in the regulation of EMT-associated stem cell-like traits by miR-612.

WNT7A/β-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer.

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King, M L; Lindberg, M E; Stodden, G R; Okuda, H; Ebers, S D; Johnson, A; Montag, A; Lengyel, E; MacLean Ii, J A; Hayashi, K

2015-06-01

We previously characterized the link between WNT7A and the progression of ovarian cancer. Other groups have identified FGF1 as a relevant risk factor in ovarian cancer. Here, we show a linkage between these two signaling pathways that may be exploited to improve treatment and prognosis of patients with ovarian cancer. High expression of WNT7A and FGF1 are correlated in ovarian carcinomas and poor overall patient survival. A chromatin immunoprecipitation assay demonstrated that WNT7A/β-catenin signaling directly regulates FGF1 expression via TCF binding elements in the FGF1-1C promoter locus. In vitro gene manipulation studies revealed that FGF1 is sufficient to drive the tumor-promoting effects of WNT7A. In vivo xenograft studies confirmed that the stable overexpression of WNT7A or FGF1 induced a significant increase in tumor incidence, whereas FGF1 knockdown in WNT7A overexpressing cells caused a significant reduction in tumor size. Niclosamide most efficiently abrogated WNT7A/β-catenin signaling in our model, inhibited β-catenin transcriptional activity and cell viability, and increased cell death. Furthermore, niclosamide decreased cell migration following an increase in E-cadherin subsequent to decreased levels of SLUG. The effects of niclosamide on cell functions were more potent in WNT7A-overexpressing cells. Oral niclosamide inhibited tumor growth and progression in an intraperitoneal xenograft mouse model representative of human ovarian cancer. Collectively, these results indicate that FGF1 is a direct downstream target of WNT7A/β-catenin signaling and this pathway has potential as a therapeutic target in ovarian cancer. Moreover, niclosamide is a promising inhibitor of this pathway and may have clinical relevance.

Novel Furocoumarin Derivatives Stimulate Melanogenesis in B16 Melanoma Cells by Up-Regulation of MITF and TYR Family via Akt/GSK3β/β-Catenin Signaling Pathways

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Chao Niu

2018-03-01

Full Text Available The extracts of Ficuscarica L. and Psoralen corylifolia L. are traditional Uygur medicines for the treatment of vitiligo, and its active ingredients furocoumarins, were are found to be the most effective agents against this skin disorder nowadays. Therefore, a series of novel easter derivatives (8a–8p of furocoumarin were designed and synthesized based on our previous research to improve this activity in the present study. The synthesized derivatives were biologically evaluated for melanin synthesis in murine B16 cells and the SAR (structure-activity relationship was summarized. Eight derivatives were more potent than positive control (8-MOP, 8-methoxypsoralan, especially compounds 8n (200% and 8o (197%, which were nearly 1.5-fold potency when compared with 8-MOP (136%. Furthermore, the signaling pathway by which 8n activates the melanin biosynthesis was defined. Our results showed that it not only elevated the melanin content, but also stimulated the activity of tyrosinasein a concentration-dependent manner. Increasing of phosphorylation of Akt (also named PKB, protein kinase B and non-activated GSK3β (glycogen synthase kinase 3 beta, which inhibited the degradation of β-catenin were observed through Western blot analysis. The accumulation of β-catenin probably led to the activation of transcription of MITF (microphthalmia-associated transcription factor and TYR (tyrosinase family, as well as the subsequent induction of melanin synthesis.

Distinct Roles of Wnt/β-Catenin Signaling in the Pathogenesis of Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis

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Shi, Juan; Li, Feng; Luo, Meihui; Wei, Jun

2017-01-01

Wnt signaling pathways are tightly controlled under a physiological condition, under which they play key roles in many biological functions, including cell fate specification and tissue regeneration. Increasing lines of evidence recently demonstrated that a dysregulated activation of Wnt signaling, particularly the Wnt/β-catenin signaling, was involved in the pathogenesis of chronic pulmonary diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). In this respect, Wnt signaling interacts with other cellular signaling pathways to regulate the initiation and pathogenic procedures of airway inflammation and remodeling, pulmonary myofibroblast proliferation, epithelial-to-mesenchymal transition (EMT), and development of emphysema. Intriguingly, Wnt/β-catenin signaling is activated in IPF; an inhibition of this signaling leads to an alleviation of pulmonary inflammation and fibrosis in experimental models. Conversely, Wnt/β-catenin signaling is inactivated in COPD tissues, and its reactivation results in an amelioration of airspace enlargement with a restored alveolar epithelial structure and function in emphysema models. These studies thus imply distinct mechanisms of Wnt/β-catenin signaling in the pathogenesis of these two chronic pulmonary diseases, indicating potential targets for COPD and IPF treatments. This review article aims to summarize the involvement and pathogenic roles of Wnt signaling pathways in the COPD and IPF, with a focus on the implication of Wnt/β-catenin signaling as underlying mechanisms and therapeutic targets in these two incurable diseases. PMID:28588349

USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination.

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Novellasdemunt, Laura; Foglizzo, Valentina; Cuadrado, Laura; Antas, Pedro; Kucharska, Anna; Encheva, Vesela; Snijders, Ambrosius P; Li, Vivian S W

2017-10-17

The tumor suppressor gene adenomatous polyposis coli (APC) is mutated in most colorectal cancers (CRCs), resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID) in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs. Copyright © 2017 The Francis Crick Institute. Published by Elsevier Inc. All rights reserved.

Identification of E2F1 as a positive transcriptional regulator for δ-catenin

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Kim, Kwonseop; Oh, Minsoo; Ki, Hyunkyoung; Wang Tao; Bareiss, Sonja; Fini, M. Elizabeth.; Li Dawei; Lu Qun

2008-01-01

δ-Catenin is upregulated in human carcinomas. However, little is known about the potential transcriptional factors that regulate δ-catenin expression in cancer. Using a human δ-catenin reporter system, we have screened several nuclear signaling modulators to test whether they can affect δ-catenin transcription. Among β-catenin/LEF-1, Notch1, and E2F1, E2F1 dramatically increased δ-catenin-luciferase activities while β-catenin/LEF-1 induced only a marginal increase. Rb suppressed the upregulation of δ-catenin-luciferase activities induced by E2F1 but did not interact with δ-catenin. RT-PCR and Western blot analyses in 4 different prostate cancer cell lines revealed that regulation of δ-catenin expression is controlled mainly at the transcriptional level. Interestingly, the effects of E2F1 on δ-catenin expression were observed only in human cancer cells expressing abundant endogenous δ-catenin. These studies identify E2F1 as a positive transcriptional regulator for δ-catenin, but further suggest the presence of strong negative regulator(s) for δ-catenin in prostate cancer cells with minimal endogenous δ-catenin expression

Alterations in Lipid Mediated Signaling and Wnt/β-Catenin Signaling in DMH Induced Colon Cancer on Supplementation of Fish Oil

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Shevali Kansal

2014-01-01

Full Text Available Ceramide mediates inhibition of cyclooxygenase-2 (COX-2 which catalyzes formation of prostaglandin further activating peroxisome proliferator-activated receptorγ (PPARγ and Wnt/β-catenin pathway; and hence plays a critical role in cancer. Therefore, in current study, ceramide, COX-2, 15-deoxy prostaglandin J2(15-deoxy PGJ2, PPARγ, and β-catenin were estimated to evaluate the effect of fish oil on lipid mediated and Wnt/β-catenin signaling in colon carcinoma. Male Wistar rats in Group I received purified diet while Groups II and III received modified diet supplemented with FO : CO(1 : 1 and FO : CO(2.5 : 1, respectively. These were further subdivided into controls receiving ethylenediaminetetraacetic acid and treated groups receiving dimethylhydrazine dihydrochloride (DMH/week for 4 weeks. Animals sacrificed 48 hours after last injection constituted initiation phase and those sacrificed after 16 weeks constituted postinitiation phase. Decreased ceramide and increased PPARγ were observed in postinitiation phase only. On receiving FO+CO(1 : 1+DMH and FO+CO(2.5 : 1+DMH in both phases, ceramide was augmented whereas COX-2, 15-deoxy PGJ2, and nuclear translocation of β-catenin were reduced with respect to cancerous animals. Decrease was more significant in postinitiation phase with FO+CO(2.5 : 1+DMH. Treatment with oils increased PPARγ in initiation phase but decreased it in postinitiation phase. Hence, fish oil altered lipid mediated signalling in a dose and time dependent manner so as to inhibit progression of colon cancer.

Beta irradiation inhibits neo-intimal formation in vein grafts

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Lang Xiaoou; Ji Shenquan; Zeng Ke; Li Jun; Liu Bingbing; Ma Wenfeng; Zhang Qiang

2002-01-01

Objective: The study was to evaluate the effect of beta irradiation on intimal proliferation response in vein grafts. Methods: An autogenous vein graft model was established in 40 rats by transplanting internal branch of jugular vein to carotid artery by end-to-end anastomosis. The vein was irradiated by 32 P before anastomosis. Four dose schedules were studied: (1) control graft (nonirradiated); (2) irradiated with 8 Gy; (3) 18 Gy; and (4) 36 Gy. The grafted veins were harvested at 2 weeks after the operation. IH (intimal hyperplasia) and SMC (smooth muscle cell) proliferation were histologically and immuno-histochemically observed and analyzed by a computer digitalising system. Results: In 18 Gy and 36 Gy-irradiated grafts compared with the control, there was a significant decrease in the average intimal thickness (P 0.05). Immunohistochemical analysis of PCNA indicated decrease of positive cells in both 18 Gy and 36 Gy groups compared with 8 Gy and the control group (P 0.05) groups, and there was also no significant difference between 8 Gy and the control group (P > 0.05). Conclusion: These preliminary results demonstrate that proper dose of beta irradiation in vein graft inhibits smooth muscle cells proliferation and neo-intimal hyperplasia in rat

Expression of delta-catenin is associated with progression of human astrocytoma

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MingHao, Wang; Qianze, Dong; Di, Zhang; YunJie, Wang

2011-01-01

δ-Catenin (CTNND2), which encodes a scaffold protein in humans, has been found in a few malignancies. However, the expression pattern and contribution of δ-catenin to astrocytoma progression are unclear. We investigated δ-catenin expression in human astrocytoma samples and its function in astrocytoma cell lines using immunohistochemistry, siRNA knockdown, transfection, MTT, transwell migration and Rac1 pulldown techniques. δ-Catenin protein expression was detected in cytoplasm of astrocytoma cells by immunohistochemistry. Analysis showed that grade I astrocytoma (0%, 0/11) and glial cells from normal brain tissue exhibited negative staining. δ-Catenin expression was significantly higher in grade III-IV (35%, 29/84) compared to grade II astrocytoma cells (18%, 11/61); p < 0.01). In addition, CTNND2 overexpression promoted proliferation, invasion and Rac1 activity of U251 astrocytoma cells. Treatment of δ-catenin-transfected cells with a Rac1 inhibitor decreased Rac1 activity and invasion. δ-Catenin knockdown in U87 glioblastoma cell decreased cell proliferation, invasion and Rac1 activity. The results suggest that δ-catenin expression is associated with the malignant progression of astrocytoma and promotes astrocytoma cell invasion through upregulation of Rac1 activity. δ-Catenin expression levels may serve as a useful marker of the biological behavior of astrocytoma cells

SOX4 inhibits GBM cell growth and induces G0/G1 cell cycle arrest through Akt-p53 axis.

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Zhang, Jing; Jiang, Huawei; Shao, Jiaofang; Mao, Ruifang; Liu, Jie; Ma, Yingying; Fang, Xuefeng; Zhao, Na; Zheng, Shu; Lin, Biaoyang

2014-11-01

SOX4 is a transcription factor required for tissue development and differentiation in vertebrates. Overexpression of SOX4 has been reported in many cancers including glioblastoma multiforme (GBM), however, the underlying mechanism of actions has not been studied. In this study, we investigated the role of SOX4 in GBM. Kaplan-Meier analysis was performed to assess the association between SOX4 expression levels and survival times in primary GBM samples. Cre/lox P system was used to generate gain or loss of SOX4 in GBM cells, and microarray analysis uncovered the regulation network of SOX4 in GBM cells. High SOX4 expression was significantly associated with good prognosis of primary GBMs. SOX4 inhibited the growth of GBM cell line LN229, A172G and U87MG, partly via the activation of p53-p21 signaling and down-regulation of phosphorylated AKT1. Gene expression profiling and subsequent gene ontology analysis showed that SOX4 influenced several key pathways including the Wnt/ beta-catenin and TGF-beta signaling pathways. Our study found that SOX4 acts as a tumor suppressor in GBM cells by induce cell cycle arrest and inhibiting cell growth.

PRELP (proline/arginine-rich end leucine-rich repeat protein) promotes osteoblastic differentiation of preosteoblastic MC3T3-E1 cells by regulating the β-catenin pathway

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Li, Haiying; Cui, Yazhou; Luan, Jing [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China); Zhang, Xiumei [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Li, Chengzhi; Zhou, Xiaoyan; Shi, Liang [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China); Wang, Huaxin [Shandong University of Traditional Chinese Medicine, Ji' an, Shandong (China); Han, Jinxiang, E-mail: jxhan9888@aliyun.com [School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Ji' nan, Shandong (China); Key Laboratory for Rare Disease Research of Shandong Province, Key Laboratory for Biotech Drugs of the Ministry of Health, Shandong Medical Biotechnological Center, Shandong Academy of Medical Sciences, Ji' nan, Shandong (China)

2016-02-12

Proline/arginine-rich end leucine-rich repeat protein (PRELP) is a collagen-binding proteoglycan highly expressed in the developing bones. Recent studies indicated that PRELP could inhibit osteoclastogenesis as a NF-κB inhibitor. However, its role during osteoblast differentiation is still unclear. In this study, we confirmed that the expression of PRELP increased with the osteogenesis induction of preosteoblastic MC3T3-E1 cells. Down-regulation of PRELP expression by shRNA reduced ALP activity, mineralization and expression of osteogenic marker gene Runx2. Our microarray analysis data suggested that β-catenin may act as a hub gene in the PRELP-mediated gene network. We validated furtherly that PRELP knockdown could inhibit the level of connexin43, a key regulator of osteoblast differentiation by affecting β-catenin protein expression, and its nuclear translocation in MC3T3-E1 preosteoblasts. Therefore, this study established a new role of PRELP in modulating β-catenin/connexin43 pathway and osteoblast differentiation.

Pentazocine Protects SN4741 Cells Against MPP+-Induced Cell Damage via Up-Regulation of the Canonical Wnt/β-Catenin Signaling Pathway

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Jiancai Wang

2017-06-01

Full Text Available The Wnt/β-catenin signaling pathway has been linked to many neurodegenerative diseases including Parkinson’s disease (PD. A glycoprotein named Dickkopf-1 (Dkk1 can combine with the receptor complex on cell membrane to inhibit Wnt/β-catenin signaling. Opioids, a series of compounds including morphine, fentanyl and pentazocine, have been reported to contribute to the up-regulation of Wnt/β-catenin signaling. Naloxone is an antagonist that has been used as an antidote to opioids through mu-opioid receptor. 1-methyl-4-phenylpyridinium (MPP+, which serves as a selective toxin for dopaminergic neurons, has been used to create experimental models of PD. In our study, we examined the protective effects of pentazocine against MPP+-induced cell death in the nigral dopaminergic cell line, SN4741 and tried to elucidate the molecular mechanisms underlying such protective effects. The data showed that pretreatment with pentazocine significantly rescued the SN4741 cell against MPP+. Moreover, the MPP+-exposed SN4741 cells exhibited a down-regulation of β-catenin, which could be restored by treatment with pentazocine. However, Dkk1 but not naloxonewas associated with the abrogation of protective effect of pentazocine. These results suggest that pentazocine alleviates MPP+-induced SN4741 cells apoptosis via the up-regulation of canonical Wnt/β-catenin signaling.

Phytochemicals attenuating aberrant activation of β-catenin in cancer cells.

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Dan Wang

Full Text Available Phytochemicals are a rich source of chemoprevention agents but their effects on modulating the Wnt/β-catenin signaling pathway have remained largely uninvestigated. Aberrantly activated Wnt signaling can result in the abnormal stabilization of β-catenin, a key causative step in a broad spectrum of cancers. Here we report the modulation of lithium chloride-activated canonical Wnt/β-catenin signaling by phytochemicals that have antioxidant, anti-inflammatory or chemopreventive properties. The compounds were first screened with a cervical cancer-derived stable Wnt signaling reporter HeLa cell line. Positive hits were subsequently evaluated for β-catenin degradation, suppression of β-catenin nuclear localization and down-regulation of downstream oncogenic targets of Wnt/β-catenin pathway. Our study shows a novel degradation path of β-catenin protein in HeLa cells by Avenanthramide 2p (a polyphenol and Triptolide (a diterpene triepoxide, respectively from oats and a Chinese medicinal plant. The findings present Avenanthramide 2p as a potential chemopreventive dietary compound that merits further study using in vivo models of cancers; they also provide a new perspective on the mechanism of action of Triptolide.

Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

International Nuclear Information System (INIS)

Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho

2005-01-01

AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear β-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear β-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3β activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death

β-Catenin is critical for cerebellar foliation and lamination.

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Jing Wen

Full Text Available The cerebellum has a conserved foliation pattern and a well-organized layered structure. The process of foliation and lamination begins around birth. β-catenin is a downstream molecule of Wnt signaling pathway, which plays a critical role in tissue organization. Lack of β-catenin at early embryonic stages leads to either prenatal or neonatal death, therefore it has been difficult to resolve its role in cerebellar foliation and lamination. Here we used GFAP-Cre to ablate β-catenin in neuronal cells of the cerebellum after embryonic day 12.5, and found an unexpected role of β-catenin in determination of the foliation pattern. In the mutant mice, the positions of fissure formation were changed, and the meninges were improperly incorporated into fissures. At later stages, some lobules were formed by Purkinje cells remaining in deep regions of the cerebellum and the laminar structure was dramatically altered. Our results suggest that β-catenin is critical for cerebellar foliation and lamination. We also found a non cell-autonomous role of β-catenin in some developmental properties of major cerebellar cell types during specific stages.

A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

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A Kolyada; C Lee; A De Biasio; N Beglova

2011-12-31

{beta}2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of {beta}2GPI generated by anti-{beta}2GPI antibodies is pathologically important, in contrast to monomeric {beta}2GPI which is abundant in plasma. We created a dimeric inhibitor, A1-A1, to selectively target {beta}2GPI in {beta}2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of {beta}2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of {beta}2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of {beta}2GPI present in human serum, {beta}2GPI purified from human plasma and the individual domain V of {beta}2GPI. We demonstrated that when {beta}2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of {beta}2GPI to cardiolipin, regardless of the source of {beta}2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of {beta}2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-{beta}2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric {beta}2GPI to cardiolipin. Our results suggest that the approach of using a dimeric inhibitor to block {beta}2GPI in the pathological multivalent {beta}2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.

Constitutive β-catenin activation in osteoblasts impairs terminal osteoblast differentiation and bone quality

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Bao, Quanwei; Chen, Sixu; Qin, Hao [State Key Laboratory of Trauma, Burn and Combined injury, Department of Trauma Surgery, Daping Hospital, Third Military Medical University, ChongQing 400042 (China); Feng, Jianquan [Department of Biomedical Sciences, Baylor College of Dentistry, Texas A& M Health Science Center, Dallas, TX 75246 (United States); Liu, Huayu; Liu, Daocheng; Li, Ang; Shen, Yue; Zhong, Xiaozheng; Li, Junfeng [State Key Laboratory of Trauma, Burn and Combined injury, Department of Trauma Surgery, Daping Hospital, Third Military Medical University, ChongQing 400042 (China); Zong, Zhaowen, E-mail: zongzhaowen@sina.cn [State Key Laboratory of Trauma, Burn and Combined injury, Department of Trauma Surgery, Daping Hospital, Third Military Medical University, ChongQing 400042 (China)

2017-01-01

Accumulating evidence suggests that Wnt/β-catenin signaling plays a central role in controlling bone mass. We previously reported that constitutive activation of β-catenin (CA-β-catenin) in osteoblasts potentially has side effects on the bone growth and bone remodeling process, although it could increase bone mass. The present study aimed to observe the effects of osteoblastic CA-β-catenin on bone quality and to investigate possible mechanisms of these effects. It was found that CA-β-catenin mice exhibited lower mineralization levels and disorganized collagen in long bones as confirmed by von Kossa staining and sirius red staining, respectively. Also, bone strength decreased significantly in CA-β-catenin mice. Then the effect of CA-β-catenin on biological functions of osteoblasts were investigated and it was found that the expression levels of osteocalcin, a marker for the late differentiation of osteoblasts, decreased in CA-β-catenin mice, while the expression levels of osterix and alkaline phosphatase, two markers for the early differentiation of osteoblasts, increased in CA-β-catenin mice. Furthermore, higher proliferation rate were revealed in osteoblasts that were isolated from CA-β-catenin mice. The Real-time PCR and western blot examination found that the expression level of c-myc and cyclin D1, two G1 progression-related molecules, increased in osteoblasts that were isolated from the CA-β-catenin mice, and the expression levels of CDK14 and cyclin Y, two mitotic-related molecules that can accelerate cells entering into S and G2/M phases, increased in osteoblasts that were isolated from the CA-β-catenin mice. In summary, osteoblastic CA-β-catenin kept osteoblasts in high proliferative state and impaired the terminal osteoblast differentiation, and this led to changed bone structure and decreased bone strength. - Highlights: • Wnt/β-catenin signaling plays a central role in controlling bone mass. • CA-β-catenin has side effects on the bone

Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

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Lee, M T; Ahmed, T; Friedman, M E

1989-01-01

Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

Regulation of Wnt/β-catenin signaling by posttranslational modifications

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2014-01-01

The canonical Wnt signaling pathway (or Wnt/β-catenin pathway) plays a pivotal role in embryonic development and adult homeostasis; deregulation of the Wnt pathway contributes to the initiation and progression of human diseases including cancer. Despite its importance in human biology and disease, how regulation of the Wnt/β-catenin pathway is achieved remains largely undefined. Increasing evidence suggests that post-translational modifications (PTMs) of Wnt pathway components are essential for the activation of the Wnt/β-catenin pathway. PTMs create a highly dynamic relay system that responds to Wnt stimulation without requiring de novo protein synthesis and offer a platform for non-Wnt pathway components to be involved in the regulation of Wnt signaling, hence providing alternative opportunities for targeting the Wnt pathway. This review highlights the current status of PTM-mediated regulation of the Wnt/β-catenin pathway with a focus on factors involved in Wnt-mediated stabilization of β-catenin. PMID:24594309

Concurrent epigenetic silencing of wnt/β-catenin pathway inhibitor genes in B cell chronic lymphocytic leukaemia

International Nuclear Information System (INIS)

Moskalev, Evgeny A; Pötz, Oliver; Joos, Thomas O; Hoheisel, Jörg D; Luckert, Katrin; Vorobjev, Ivan A; Mastitsky, Sergey E; Gladkikh, Aleena A; Stephan, Achim; Schrenk, Marita; Kaplanov, Kamil D; Kalashnikova, Olga B

2012-01-01

The Wnt/β-catenin signalling is aberrantly activated in primary B cell chronic lymphocytic leukaemia (CLL). Epigenetic silencing of pathway inhibitor genes may be a mechanism for its activation. In this study, we investigated systematically and quantitatively the methylation status of 12 Wnt/β-catenin pathway inhibitor genes – CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 and WIF1 – in the cell lines EHEB and MEC-1 as well as patient samples. Quantification of DNA methylation was performed by means of bisulphite pyrosequencing and confirmed by bisulphite Sanger sequencing. Gene expression was analysed by qPCR using GAPDH as internal control. E-cadherin and β-catenin protein quantification was carried out by microsphere-based immunoassays. Methylation differences observed between the patient and control groups were tested using generalised least squares models. For 10 genes, a higher methylation level was observed in tumour material. Only DKK4 exhibited similarly high methylation levels in both tumour and normal specimens, while DACT1 was always essentially unmethylated. However, also for these inhibitors, treatment of cells with the demethylating agent 5-aza-2´-deoxycytidine resulted in an induction of their expression, as shown by quantitative PCR, suggesting an indirect epigenetic control of activity. While the degree of demethylation and its transcriptional consequences differed between the genes, there was an overall high correlation of demethylation and increased activity. Protein expression studies revealed that no constitutive Wnt/β-catenin signalling occurred in the cell lines, which is in discrepancy with results from primary CLL. However, treatment with 5-aza-2´-deoxycytidine caused accumulation of β-catenin. Simultaneously, E-cadherin expression was strongly induced, leading to the formation of a complex with β-catenin and thus demonstrating its epigenetically regulated inhibition effect. The results suggest an

Histone deacetylase 4 promotes TGF-beta1-induced synovium-derived stem cell chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy.

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Pei, Ming; Chen, Demeng; Li, Jingting; Wei, Lei

2009-12-01

The transforming growth factor-beta (TGF-beta) superfamily members play diverse roles in cartilage development and maintenance. TGF-beta up-regulates chondrogenic gene expression by enhancing transcription factor SRY (sex determining region Y)-box 9 (Sox9) and inhibits osteoblast differentiation by repressing runt-related transcription factor 2 (Runx2). Recently, histone deacetylases (HDACs) were reported to act as negative regulators of chondrocyte hypertrophy. It was speculated that HDAC4 may promote TGF-beta1-induced MSC chondrogenesis. In this study, the adenovirus-mediated HDAC4 gene (Ad.HDAC4) was utilized to infect synovium-derived stem cells (SDSCs). Adenovirus-mediated LacZ (Ad.LacZ) served as a control. The infected cells were centrifuged to form SDSC pellets followed by incubation in a serum-free chondrogenic medium for 15 days with or without 10ng/mL TGF-beta1. Transfection efficiency was determined in SDSCs using Ad.LacZ. Cytotoxicity was measured using lactate dehydrogenase assay. Histology, immunostaining, biochemical analysis, and real-time polymerase chain reaction were performed to assess chondrogenesis at protein and mRNA levels in infected SDSCs. Our data demonstrated that supplementation with TGF-beta1 could initiate and promote SDSC chondrogenesis; however, TGF-beta1 alone was insufficient to fully differentiate SDSCs into chondrocytes. Ad.HDAC4 could be efficiently transfected into SDSCs. Without TGF-beta1 treatment, HDAC4 had no effect on SDSC chondrogenesis; however, in the presence of TGF-beta1, HDAC4 could speed up and maintain a high level of chondrogenesis while down-regulating the hypertrophic marker - type X collagen expression. This study is the first report showing that HDAC4 overexpression promotes TGF-beta1-induced SDSC chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy. The mechanism underlying this process needs further investigation.

δ-Catenin Regulates Spine Architecture via Cadherin and PDZ-dependent Interactions*

Science.gov (United States)

Yuan, Li; Seong, Eunju; Beuscher, James L.; Arikkath, Jyothi

2015-01-01

The ability of neurons to maintain spine architecture and modulate it in response to synaptic activity is a crucial component of the cellular machinery that underlies information storage in pyramidal neurons of the hippocampus. Here we show a critical role for δ-catenin, a component of the cadherin-catenin cell adhesion complex, in regulating spine head width and length in pyramidal neurons of the hippocampus. The loss of Ctnnd2, the gene encoding δ-catenin, has been associated with the intellectual disability observed in the cri du chat syndrome, suggesting that the functional roles of δ-catenin are vital for neuronal integrity and higher order functions. We demonstrate that loss of δ-catenin in a mouse model or knockdown of δ-catenin in pyramidal neurons compromises spine head width and length, without altering spine dynamics. This is accompanied by a reduction in the levels of synaptic N-cadherin. The ability of δ-catenin to modulate spine architecture is critically dependent on its ability to interact with cadherin and PDZ domain-containing proteins. We propose that loss of δ-catenin during development perturbs synaptic architecture leading to developmental aberrations in neural circuit formation that contribute to the learning disabilities in a mouse model and humans with cri du chat syndrome. PMID:25724647

Paracrine Activation of the Wnt/β-Catenin Pathway by Bone Marrow Stem Cell Attenuates Cisplatin-Induced Kidney Injury

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Xiaoyan Jiao

2017-12-01

Full Text Available Background/Aims: Cisplatin-induced acute kidney injury (AKI involves damage to tubular cells via excess reactive oxygen species (ROS generation. Stem cell-based therapies have shown great promise in AKI treatment. In this study, we aimed to assess the protective effect and mechanism of bone marrow mesenchymal stem cell (BMSC-derived conditioned medium (CM against cisplatin-induced AKI. Methods: In vitro, NRK-52E cells were incubated with cisplatin in the presence or absence of CM, followed by the assessment of cell viability, apoptosis and cell cycle distribution. Then, ICG-001 and IWR-1 were used to inhibit the wnt/β-catenin pathway. Furthermore, intracellular and mitochondrial ROS levels were evaluated using DCFH-DA and MitoSOX, respectively. In vivo, after cisplatin injection, rats were intravenously injected with CM or BMSCs. Sera and kidney tissues were collected on day 3 after cisplatin injection to evaluate changes in renal function and histology. Western blotting and qRT-PCR were employed to determine the expression of wnt/β-catenin pathway-related genes and proteins. Immunohistochemical staining was used to evaluate tubular β-catenin expression in kidney biopsy from AKI patients. Results: CM protected NRK-52E cells from cisplatin-induced injury by restoring the wnt4/β-catenin pathway. In response to ICG-001 and IWR-1, the protective effect of CM was attenuated, characterized by a decrease in cell proliferation and an increase in cell apoptosis and intracellular and mitochondrial ROS levels. Knockdown of β-catenin using siRNAs also suppressed the mitochondrial biogenesis regulators PGC-1α, TFAM and NRF-1. In the rat model, CM significantly alleviated renal function and histology associated with tubular injury and upregulated wnt4 and β-catenin. However, the renoprotective effect of CM was blocked by ICG-001, characterized by exacerbated renal function, suppressed PGC-1α expression and increased mitochondrial ROS. Clinical data

Paracrine Activation of the Wnt/β-Catenin Pathway by Bone Marrow Stem Cell Attenuates Cisplatin-Induced Kidney Injury.

Science.gov (United States)

Jiao, Xiaoyan; Cai, Jieru; Yu, Xiaofang; Ding, Xiaoqiang

2017-01-01

Cisplatin-induced acute kidney injury (AKI) involves damage to tubular cells via excess reactive oxygen species (ROS) generation. Stem cell-based therapies have shown great promise in AKI treatment. In this study, we aimed to assess the protective effect and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived conditioned medium (CM) against cisplatin-induced AKI. In vitro, NRK-52E cells were incubated with cisplatin in the presence or absence of CM, followed by the assessment of cell viability, apoptosis and cell cycle distribution. Then, ICG-001 and IWR-1 were used to inhibit the wnt/β-catenin pathway. Furthermore, intracellular and mitochondrial ROS levels were evaluated using DCFH-DA and MitoSOX, respectively. In vivo, after cisplatin injection, rats were intravenously injected with CM or BMSCs. Sera and kidney tissues were collected on day 3 after cisplatin injection to evaluate changes in renal function and histology. Western blotting and qRT-PCR were employed to determine the expression of wnt/β-catenin pathway-related genes and proteins. Immunohistochemical staining was used to evaluate tubular β-catenin expression in kidney biopsy from AKI patients. CM protected NRK-52E cells from cisplatin-induced injury by restoring the wnt4/β-catenin pathway. In response to ICG-001 and IWR-1, the protective effect of CM was attenuated, characterized by a decrease in cell proliferation and an increase in cell apoptosis and intracellular and mitochondrial ROS levels. Knockdown of β-catenin using siRNAs also suppressed the mitochondrial biogenesis regulators PGC-1α, TFAM and NRF-1. In the rat model, CM significantly alleviated renal function and histology associated with tubular injury and upregulated wnt4 and β-catenin. However, the renoprotective effect of CM was blocked by ICG-001, characterized by exacerbated renal function, suppressed PGC-1α expression and increased mitochondrial ROS. Clinical data showed that the tubular β-catenin level was lower in

Inhibition of B cell proliferation by antisense DNA to both alpha and beta forms of Fc epsilon R II.

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Bhatti, L; Behle, K; Stevens, R H

1992-10-01

Epstein-Barr Virus (EBV) infection activates B lymphocyte proliferation through partially understood mechanisms, resulting in phenotypic changes, including the appearance of new antigens. One such antigen is Fc epsilon R II/CD-23 which may be relevant for B cell proliferation. We have used anti-sense oligonucleotides to study the importance of the two forms of this molecule for proliferation in the EBV-transformed, Fc epsilon R II +ve lymphoblastoid B cell line, RPMI 8866. Anti-sense oligodeoxynucleotides were generated to the two forms of Fc epsilon R II; Fc epsilon R IIa (alpha) and IIb (beta) which differ only in their intracytoplasmic domains. Addition of increasing concentrations of anti-sense oligonucleotides, ranging from 1 to 30 microM, significantly decreased cellular proliferation as measured by the incorporation of [3H]thymidine (inhibition range 8-88%). Optimum inhibition of cellular proliferation was apparent at 15 microM concentration of both anti-sense Fc epsilon R IIa and IIb (Fc epsilon R IIa, mean +/- SE = 75 +/- 7% inhibition, p less than 0.001; Fc epsilon R IIb, mean +/- SE = 71 +/- 7% inhibition, p less than 0.001). Anti-sense oligonucleotides complementary to the common part of Fc epsilon R II resulted in a similar inhibition of proliferation. Sense oligonucleotides did not induce significant inhibition. Preincubation of sense and anti-sense oligonucleotides resulted in an abrogation of proliferation inhibition. Moreover, none of these oligonucleotides had any effect on a Fc epsilon R II -ve cell line. Incubation with both anti-sense IIa and IIb resulted in additive, but not synergistic inhibition of proliferation. Addition of soluble Fc epsilon R II did not reverse inhibition of proliferation, suggesting that membrane-bound or intracellular rather than soluble Fc epsilon R II was important for the induced proliferation. Analysis of cell surface expression for Fc epsilon II indicated that while there was a pronounced effect on cell number

Dietary pectin and calcium inhibit colonic proliferation in vivo by differing mechanisms.

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Umar, S; Morris, A P; Kourouma, F; Sellin, J H

2003-12-01

Diet plays an important role in promoting and/or preventing colon cancer; however, the effects of specific nutrients remain uncertain because of the difficulties in correlating epidemiological and basic observations. Transmissible murine colonic hyperplasia (TMCH) induced by Citrobacter rodentium, causes significant hyperproliferation and hyperplasia in the mouse distal colon and increases the risk of subsequent neoplasia. We have recently shown that TMCH is associated with an increased abundance of cellular beta-catenin and its nuclear translocation coupled with up-regulation of its downstream targets, c-myc and cyclin D1. In this study, we examined the effects of two putatively protective nutrients, calcium and soluble fibre pectin, on molecular events linked to proliferation in the colonic epithelium during TMCH. Dietary intervention incorporating changes in calcium [high (1.0%) and low (0.1%)] and alterations in fibre content (6% pectin and fibre-free) were compared with the standard AIN-93 diet (0.5% calcium, 5% cellulose), followed by histomorphometry and immunochemical assessment of potential oncogenes. Dietary interventions did not alter the time course of Citrobacter infection. Both 1.0% calcium and 6% pectin diet inhibited increases in proliferation and crypt length typically seen in TMCH. Neither the low calcium nor fibre-free diets had significant effect. Pectin diet blocked increases in cellular beta-catenin, cyclin D1 and c-myc levels associated with TMCH by 70%, whereas neither high nor low calcium diet had significant effect on these molecules. Diets supplemented with either calcium or pectin therefore, exert anti-proliferative effects in mouse distal colon involving different molecular pathways. TMCH is thus a diet-sensitive model for examining the effect of specific nutrients on molecular characteristics of the pre-neoplastic colonic epithelium.

The expression and mutation of β-catenin in colorectal traditional serrated adenomas

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Xiaojun Dai

2012-01-01

Full Text Available Context : Exon 3 mutation of β-catenin is associated with the carcinogenesis. Aims: In this study we aimed to detect the expression of exon 3 mutations of β-catenin in colorectal TSA, TA/VTA, and CRC. Materials and Methods : Immunohistochemistry staining for β-catenin was performed for 30 TSA, 20 tubular adenomas (TA/villous tubular adenomas (VTA, and 21 colorectal carcinoma (CRC cases. DNA sequencing of the exon 3 of β-catenin gene was performed for 8 TSA cases, 6 TA cases, 5 VTA cases, and 10 CRC cases with positive staining in the nuclei and cytoplasm. Statistical Analysis: A Fisher exact test and chi-square test were used to analyze the differentiations of the expression of β-catenin in TSA, TA/VTA, and CRC. Results : The percentages of β-catenin expression in TSA, TA/VTA, and CRC were 76.6% (23/30, 70.0% (14/20, and 95.2% (20/21, respectively, and were significantly different among these three types of tissue specimens (χ2 = 22.805, P < 0.001. Although β-catenin expression levels in TSA were not related to it in TA/VTA, they were significantly different between TSA/TA/VTA and CRC. The degree of dysplasia was well correlated with β-catenin expression (TSA: P < 0.01; TA/VTA: P < 0.05. But β-catenin exon 3 mutations were not detected in any of these tissue specimens. Conclusions : Aberrant β-catenin expression is associated with the degree of dysplasia in TSA. β-catenin likely plays an important role in the pathogenesis of colorectal TSA and conventional adenomas.

Canonical Wnt/β-catenin signalling is essential for optic cup formation.

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Anna-Carin Hägglund

Full Text Available A multitude of signalling pathways are involved in the process of forming an eye. Here we demonstrate that β-catenin is essential for eye development as inactivation of β-catenin prior to cellular specification in the optic vesicle caused anophthalmia in mice. By achieving this early and tissue-specific β-catenin inactivation we find that retinal pigment epithelium (RPE commitment was blocked and eye development was arrested prior to optic cup formation due to a loss of canonical Wnt signalling in the dorsal optic vesicle. Thus, these results show that Wnt/β-catenin signalling is required earlier and play a more central role in eye development than previous studies have indicated. In our genetic model system a few RPE cells could escape β-catenin inactivation leading to the formation of a small optic rudiment. The optic rudiment contained several neural retinal cell classes surrounded by an RPE. Unlike the RPE cells, the neural retinal cells could be β-catenin-negative revealing that differentiation of the neural retinal cell classes is β-catenin-independent. Moreover, although dorsoventral patterning is initiated in the mutant optic vesicle, the neural retinal cells in the optic rudiment displayed almost exclusively ventral identity. Thus, β-catenin is required for optic cup formation, commitment to RPE cells and maintenance of dorsal identity of the retina.

δ-Catenin Regulates Spine Architecture via Cadherin and PDZ-dependent Interactions.

Science.gov (United States)

Yuan, Li; Seong, Eunju; Beuscher, James L; Arikkath, Jyothi

2015-04-24

The ability of neurons to maintain spine architecture and modulate it in response to synaptic activity is a crucial component of the cellular machinery that underlies information storage in pyramidal neurons of the hippocampus. Here we show a critical role for δ-catenin, a component of the cadherin-catenin cell adhesion complex, in regulating spine head width and length in pyramidal neurons of the hippocampus. The loss of Ctnnd2, the gene encoding δ-catenin, has been associated with the intellectual disability observed in the cri du chat syndrome, suggesting that the functional roles of δ-catenin are vital for neuronal integrity and higher order functions. We demonstrate that loss of δ-catenin in a mouse model or knockdown of δ-catenin in pyramidal neurons compromises spine head width and length, without altering spine dynamics. This is accompanied by a reduction in the levels of synaptic N-cadherin. The ability of δ-catenin to modulate spine architecture is critically dependent on its ability to interact with cadherin and PDZ domain-containing proteins. We propose that loss of δ-catenin during development perturbs synaptic architecture leading to developmental aberrations in neural circuit formation that contribute to the learning disabilities in a mouse model and humans with cri du chat syndrome. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Canine tracheal epithelial cells are more sensitive than rat tracheal epithelial cells to transforming growth factor beta induced growth inhibition