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Sample records for p120 catenin 1a

  1. P120-catenin isoforms 1A and 3A differently affect invasion and proliferation of lung cancer cells

    International Nuclear Information System (INIS)

    Liu Yang; Dong Qianze; Zhao Yue; Dong Xinjun; Miao Yuan; Dai Shundong; Yang Zhiqiang; Zhang Di; Wang Yan; Li Qingchang; Zhao Chen; Wang Enhua

    2009-01-01

    Different isoforms of p120-catenin (p120ctn), a member of the Armadillo gene family, are variably expressed in different tissues as a result of alternative splicing and the use of multiple translation initiation codons. When expressed in cancer cells, these isoforms may confer different properties with respect to cell adhesion and invasion. We have previously reported that the p120ctn isoforms 1 and 3 were the most highly expressed isoforms in normal lung tissues, and their expression level was reduced in lung tumor cells. To precisely define their biological roles, we transfected p120ctn isoforms 1A and 3A into the lung cancer cell lines A549 and NCI-H460. Enhanced expression of p120ctn isoform 1A not only upregulated E-cadherin and β-catenin, but also downregulated the Rac1 activity, and as a result, inhibited the ability of cells to invade. In contrast, overexpression of p120ctn isoform 3A led to the inactivation of Cdc42 and the activation of RhoA, and had a smaller influence on invasion. However, we found that isoform 3A had a greater ability than isoform 1A in both inhibiting the cell cycle and reducing tumor cell proliferation. The present study revealed that p120ctn isoforms 1A and 3A differently regulated the adhesive, proliferative, and invasive properties of lung cancer cells through distinct mechanisms

  2. Targeted p120-catenin ablation disrupts dental enamel development.

    Science.gov (United States)

    Bartlett, John D; Dobeck, Justine M; Tye, Coralee E; Perez-Moreno, Mirna; Stokes, Nicole; Reynolds, Albert B; Fuchs, Elaine; Skobe, Ziedonis

    2010-09-16

    Dental enamel development occurs in stages. The ameloblast cell layer is adjacent to, and is responsible for, enamel formation. When rodent pre-ameloblasts become tall columnar secretory-stage ameloblasts, they secrete enamel matrix proteins, and the ameloblasts start moving in rows that slide by one another. This movement is necessary to form the characteristic decussating enamel prism pattern. Thus, a dynamic system of intercellular interactions is required for proper enamel development. Cadherins are components of the adherens junction (AJ), and they span the cell membrane to mediate attachment to adjacent cells. p120 stabilizes cadherins by preventing their internalization and degradation. So, we asked if p120-mediated cadherin stability is important for dental enamel formation. Targeted p120 ablation in the mouse enamel organ had a striking effect. Secretory stage ameloblasts detached from surrounding tissues, lost polarity, flattened, and ameloblast E- and N-cadherin expression became undetectable by immunostaining. The enamel itself was poorly mineralized and appeared to be composed of a thin layer of merged spheres that abraded from the tooth. Significantly, p120 mosaic mouse teeth were capable of forming normal enamel demonstrating that the enamel defects were not a secondary effect of p120 ablation. Surprisingly, blood-filled sinusoids developed in random locations around the developing teeth. This has not been observed in other p120-ablated tissues and may be due to altered p120-mediated cell signaling. These data reveal a critical role for p120 in tooth and dental enamel development and are consistent with p120 directing the attachment and detachment of the secretory stage ameloblasts as they move in rows.

  3. Targeted p120-catenin ablation disrupts dental enamel development

    DEFF Research Database (Denmark)

    Bartlett, John D; Dobeck, Justine M; Tye, Coralee E

    2010-01-01

    Dental enamel development occurs in stages. The ameloblast cell layer is adjacent to, and is responsible for, enamel formation. When rodent pre-ameloblasts become tall columnar secretory-stage ameloblasts, they secrete enamel matrix proteins, and the ameloblasts start moving in rows that slide...... by one another. This movement is necessary to form the characteristic decussating enamel prism pattern. Thus, a dynamic system of intercellular interactions is required for proper enamel development. Cadherins are components of the adherens junction (AJ), and they span the cell membrane to mediate...... attachment to adjacent cells. p120 stabilizes cadherins by preventing their internalization and degradation. So, we asked if p120-mediated cadherin stability is important for dental enamel formation. Targeted p120 ablation in the mouse enamel organ had a striking effect. Secretory stage ameloblasts detached...

  4. The molecular evolution of the p120-catenin subfamily and its functional associations.

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    Robert H Carnahan

    2010-12-01

    Full Text Available p120-catenin (p120 is the prototypical member of a subclass of armadillo-related proteins that includes δ-catenin/NPRAP, ARVCF, p0071, and the more distantly related plakophilins 1-3. In vertebrates, p120 is essential in regulating surface expression and stability of all classical cadherins, and directly interacts with Kaiso, a BTB/ZF family transcription factor.To clarify functional relationships between these proteins and how they relate to the classical cadherins, we have examined the proteomes of 14 diverse vertebrate and metazoan species. The data reveal a single ancient δ-catenin-like p120 family member present in the earliest metazoans and conserved throughout metazoan evolution. This single p120 family protein is present in all protostomes, and in certain early-branching chordate lineages. Phylogenetic analyses suggest that gene duplication and functional diversification into "p120-like" and "δ-catenin-like" proteins occurred in the urochordate-vertebrate ancestor. Additional gene duplications during early vertebrate evolution gave rise to the seven vertebrate p120 family members. Kaiso family members (i.e., Kaiso, ZBTB38 and ZBTB4 are found only in vertebrates, their origin following that of the p120-like gene lineage and coinciding with the evolution of vertebrate-specific mechanisms of epigenetic gene regulation by CpG island methylation.The p120 protein family evolved from a common δ-catenin-like ancestor present in all metazoans. Through several rounds of gene duplication and diversification, however, p120 evolved in vertebrates into an essential, ubiquitously expressed protein, whereas loss of the more selectively expressed δ-catenin, p0071 and ARVCF are tolerated in most species. Together with phylogenetic studies of the vertebrate cadherins, our data suggest that the p120-like and δ-catenin-like genes co-evolved separately with non-neural (E- and P-cadherin and neural (N- and R-cadherin cadherin lineages, respectively. The

  5. P120-Catenin Regulates Early Trafficking Stages of the N-Cadherin Precursor Complex.

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    Diana P Wehrendt

    Full Text Available It is well established that binding of p120 catenin to the cytoplasmic domain of surface cadherin prevents cadherin endocytosis and degradation, contributing to cell-cell adhesion. In the present work we show that p120 catenin bound to the N-cadherin precursor, contributes to its anterograde movement from the endoplasmic reticulum (ER to the Golgi complex. In HeLa cells, depletion of p120 expression, or blocking its binding to N-cadherin, increased the accumulation of the precursor in the ER, while it decreased the localization of mature N-cadherin at intercellular junctions. Reconstitution experiments in p120-deficient SW48 cells with all three major isoforms of p120 (1, 3 and 4 had similar capacity to promote the processing of the N-cadherin precursor to the mature form, and its localization at cell-cell junctions. P120 catenin and protein tyrosine phosphatase PTP1B facilitated the recruitment of the N-ethylmaleimide sensitive factor (NSF, an ATPase involved in vesicular trafficking, to the N-cadherin precursor complex. Dominant negative NSF E329Q impaired N-cadherin trafficking, maturation and localization at cell-cell junctions. Our results uncover a new role for p120 catenin bound to the N-cadherin precursor ensuring its trafficking through the biosynthetic pathway towards the cell surface.

  6. Pro-Tumorigenic Phosphorylation of p120 Catenin in Renal and Breast Cancer.

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    Antonis Kourtidis

    Full Text Available Altered protein expression and phosphorylation are common events during malignant transformation. These perturbations have been widely explored in the context of E-cadherin cell-cell adhesion complexes, which are central in the maintenance of the normal epithelial phenotype. A major component of these complexes is p120 catenin (p120, which binds and stabilizes E-cadherin to promote its adhesive and tumor suppressing function. However, p120 is also an essential mediator of pro-tumorigenic signals driven by oncogenes, such as Src, and can be phosphorylated at multiple sites. Although alterations in p120 expression have been extensively studied by immunohistochemistry (IHC in the context of tumor progression, little is known about the status and role of p120 phosphorylation in cancer. Here we show that tyrosine and threonine phosphorylation of p120 in two sites, Y228 and T916, is elevated in renal and breast tumor tissue samples. We also show that tyrosine phosphorylation of p120 at its N-terminus, including at the Y228 site is required for its pro-tumorigenic potential. In contrast, phosphorylation of p120 at T916 does not affect this p120 function. However, phosphorylation of p120 at T916 interferes with epitope recognition of the most commonly used p120 antibody, namely pp120. As a result, this antibody selectively underrepresents p120 levels in tumor tissues, where p120 is phosphorylated. Overall, our data support a role of p120 phosphorylation as a marker and mediator of tumor transformation. Importantly, they also argue that the level and localization of p120 in human cancer tissues immunostained with pp120 needs to be re-evaluated.

  7. p120-catenin differentially regulates cell migration by Rho-dependent intracellular and secreted signals

    DEFF Research Database (Denmark)

    Epifano, Carolina; Megias, Diego; Perez-Moreno, Mirna

    2014-01-01

    The adherens junction protein p120-catenin is implicated in the regulation of cadherin stability, cell migration and inflammatory responses in mammalian epithelial tissues. How these events are coordinated to promote wound repair is not understood. We show that p120 catenin regulates the intrinsic...... migratory properties of primary mouse keratinocytes, but also influences the migratory behavior of neighboring cells by secreted signals. These events are rooted in the ability of p120-catenin to regulate RhoA GTPase activity, which leads to a two-tiered control of cell migration. One restrains cell...... motility via an increase in actin stress fibers, reduction in integrin turnover and an increase in the robustness of focal adhesions. The other is coupled to the secretion of inflammatory cytokines including interleukin-24, which causally enhances randomized cell movements. Taken together, our results...

  8. p120-Catenin Is Critical for the Development of Invasive Lobular Carcinoma in Mice.

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    Tenhagen, Milou; Klarenbeek, Sjoerd; Braumuller, Tanya M; Hofmann, Ilse; van der Groep, Petra; Ter Hoeve, Natalie; van der Wall, Elsken; Jonkers, Jos; Derksen, Patrick W B

    2016-12-01

    Loss of E-cadherin expression is causal to the development of invasive lobular breast carcinoma (ILC). E-cadherin loss leads to dismantling of the adherens junction and subsequent translocation of p120-catenin (p120) to the cytosol and nucleus. Although p120 is critical for the metastatic potential of ILC through the regulation of Rock-dependent anoikis resistance, it remains unknown whether p120 also contributes to ILC development. Using genetically engineered mouse models with mammary gland-specific inactivation of E-cadherin, p120 and p53, we demonstrate that ILC formation induced by E-cadherin and p53 loss is severely impaired upon concomitant inactivation of p120. Tumors that developed in the triple-knockout mice were mostly basal sarcomatoid carcinomas that displayed overt nuclear atypia and multinucleation. In line with the strong reduction in ILC incidence in triple-knockout mice compared to E-cadherin and p53 double-knockout mice, no functional redundancy of p120 family members was observed in mouse ILC development, as expression and localization of ARVCF, p0071 or δ-catenin was unaltered in ILCs from triple-knockout mice. In conclusion, we show that loss of p120 in the context of the p53-deficient mouse models is dominant over E-cadherin inactivation and its inactivation promotes the development of basal, epithelial-to-mesenchymal-transition (EMT)-type invasive mammary tumors.

  9. Loss of p120 catenin and links to mitotic alterations, inflammation, and skin cancer

    DEFF Research Database (Denmark)

    Perez-Moreno, Mirna; Song, Weimin; Pasolli, H Amalia

    2008-01-01

    Tumor formation involves epigenetic modifications and microenvironmental changes as well as cumulative genetic alterations encompassing somatic mutations, loss of heterozygosity, and aneuploidy. Here, we show that conditional targeting of p120 catenin in mice leads to progressive development...... of skin neoplasias associated with intrinsic NF-kappaB activation. We find that, similarly, squamous cell carcinomas in humans display altered p120 and activated NF-kappaB. We show that epidermal hyperproliferation arising from p120 loss can be abrogated by IkappaB kinase 2 inhibitors. Although...... this underscores the importance of this pathway, the role of NF-kappaB in hyperproliferation appears rooted in its impact on epidermal microenvironment because as p120-null keratinocytes display a growth-arrested phenotype in culture. We trace this to a mitotic defect, resulting in unstable, binucleated cells...

  10. Ablation of p120-Catenin Altering the Activity of Small GTPase in Human Lung Cancer Cells

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    Nan LIU

    2009-05-01

    Full Text Available Background and objective p120-catenin (p120ctn, a member of the Armadillo gene family, has emerged as an important modulator of small GTPase activities. Therefore, it plays novel roles in tumor malignant phenotype, such as invasion and metastasis, whose mechanism are not well clarified yet. The aim of this study is to explore the roles of p120ctn on the regulation of small GTP family members in lung cancer and the effects to lung cancer invasions andmetastasis. Methods After p120ctn was knocked down by siRNA, in vivo and in vitro analysis was applied to investigate the role and possible mechanism of p120ctn in lung cancer, such as Western Blot, pull-down analysis, and nude mice models. Results p120ctn depletion inactivated RhoA, with the the activity of Cdc42 and Rac1 increased, the invasiveness of lung cancer cells was promoted both in vitro and in vivo . Conclusion p120ctn gene knockdown enhances the metastasis of lung cancer cells, probably by altering expression of small GTPase, such as inactivation of RhoA and activation of Cdc42/Rac1.

  11. p120 Catenin-Mediated Stabilization of E-Cadherin Is Essential for Primitive Endoderm Specification.

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    Tim Pieters

    2016-08-01

    Full Text Available E-cadherin-mediated cell-cell adhesion is critical for naive pluripotency of cultured mouse embryonic stem cells (mESCs. E-cadherin-depleted mESC fail to downregulate their pluripotency program and are unable to initiate lineage commitment. To further explore the roles of cell adhesion molecules during mESC differentiation, we focused on p120 catenin (p120ctn. Although one key function of p120ctn is to stabilize and regulate cadherin-mediated cell-cell adhesion, it has many additional functions, including regulation of transcription and Rho GTPase activity. Here, we investigated the role of mouse p120ctn in early embryogenesis, mESC pluripotency and early fate determination. In contrast to the E-cadherin-null phenotype, p120ctn-null mESCs remained pluripotent, but their in vitro differentiation was incomplete. In particular, they failed to form cystic embryoid bodies and showed defects in primitive endoderm formation. To pinpoint the underlying mechanism, we undertook a structure-function approach. Rescue of p120ctn-null mESCs with different p120ctn wild-type and mutant expression constructs revealed that the long N-terminal domain of p120ctn and its regulatory domain for RhoA were dispensable, whereas its armadillo domain and interaction with E-cadherin were crucial for primitive endoderm formation. We conclude that p120ctn is not only an adaptor and regulator of E-cadherin, but is also indispensable for proper lineage commitment.

  12. DIPA-family coiled-coils bind conserved isoform-specific head domain of p120-catenin family: potential roles in hydrocephalus and heterotopia.

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    Markham, Nicholas O; Doll, Caleb A; Dohn, Michael R; Miller, Rachel K; Yu, Huapeng; Coffey, Robert J; McCrea, Pierre D; Gamse, Joshua T; Reynolds, Albert B

    2014-09-01

    p120-catenin (p120) modulates adherens junction (AJ) dynamics by controlling the stability of classical cadherins. Among all p120 isoforms, p120-3A and p120-1A are the most prevalent. Both stabilize cadherins, but p120-3A is preferred in epithelia, whereas p120-1A takes precedence in neurons, fibroblasts, and macrophages. During epithelial-to-mesenchymal transition, E- to N-cadherin switching coincides with p120-3A to -1A alternative splicing. These isoforms differ by a 101-amino acid "head domain" comprising the p120-1A N-terminus. Although its exact role is unknown, the head domain likely mediates developmental and cancer-associated events linked to p120-1A expression (e.g., motility, invasion, metastasis). Here we identified delta-interacting protein A (DIPA) as the first head domain-specific binding partner and candidate mediator of isoform 1A activity. DIPA colocalizes with AJs in a p120-1A- but not 3A-dependent manner. Moreover, all DIPA family members (Ccdc85a, Ccdc85b/DIPA, and Ccdc85c) interact reciprocally with p120 family members (p120, δ-catenin, p0071, and ARVCF), suggesting significant functional overlap. During zebrafish neural tube development, both knockdown and overexpression of DIPA phenocopy N-cadherin mutations, an effect bearing functional ties to a reported mouse hydrocephalus phenotype associated with Ccdc85c. These studies identify a novel, highly conserved interaction between two protein families that may participate either individually or collectively in N-cadherin-mediated development. © 2014 Markham et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  13. Effect of p120 catenin silencing on biological behaviors of PANC-1 cells.

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    Cheng, Zhangjun; Assfag, Volker; Shi, Xin; Lin, Shibo; Xia, Jiangyan; Yang, Pinghua; Hüser, Norbert; Shen, Feng

    2012-10-01

    This study examined the possible role of p120ctn in the pathogenesis and development of pancreatic cancer. PANC-1 cells, a kind of human pancreatic carcinoma cell line, were cultured in this study. p120ctn was immunocytochemically detected in PANC-1 cells. The recombinant lentivirus vector was constructed to knock down the p120ctn expression of PANC-1 cells. Real-time quantitative PCR (RQ-PCR) and Western blotting were used to determine the expression of p120ctn and E-cadherin in PANC-1 cells after p120ctn knockdown. The adhesion, invasion and migration capacity of PANC-1 cells after p120ctn knockdown was detected by cell adhesion, invasion and migration assays. Cell growth was measured by the MTT method. Cell cycle and apoptosis were analyzed by fluorescence-activated cell sorting. The results showed that p120ctn knockdown led to significantly down-regulated E-cadherin and a reduced cell-to-cell adhesion ability in PANC-1 cells. shRNA-mediated knockdown of p120ctn reduced invasion and migration capacity of PANC-1 cells, inhibited cell growth, caused a significant decrease in the percentage of cells in G(1), an increase in S, and promoted apoptosis of PANC-1 cells. It was concluded that p120ctn plays a pivotal role in the proliferation and metastasis of pancreatic carcinoma, suggesting that p120ctn is a novel target for pancreatic carcinoma treatment.

  14. Glycoprotein 90K Promotes E-Cadherin Degradation in a Cell Density-Dependent Manner via Dissociation of E-Cadherin–p120-Catenin Complex

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    So-Yeon Park

    2017-12-01

    Full Text Available Glycoprotein 90K (also known as LGALS3BP or Mac-2BP is a tumor-associated protein, and high 90K levels are associated with poor prognosis in some cancers. To clarify the role of 90K as an indicator for poor prognosis and metastasis in epithelial cancers, the present study investigated the effect of 90K on an adherens junctional protein, E-cadherin, which is frequently absent or downregulated in human epithelial cancers. Treatment of certain cancer cells with 90K significantly reduced E-cadherin levels in a cell-population-dependent manner, and these cells showed decreases in cell adhesion and increases in invasive cell motility. Mechanistically, 90K-induced E-cadherin downregulation occurred via ubiquitination-mediated proteasomal degradation. 90K interacted with the E-cadherin–p120-catenin complex and induced its dissociation, altering the phosphorylation status of p120-catenin, whereas it did not associate with β-catenin. In subconfluent cells, 90K decreased membrane-localized p120-catenin and the membrane fraction of the p120-catenin. Particularly, 90K-induced E-cadherin downregulation was diminished in p120-catenin knocked-down cells. Taken together, 90K upregulation promotes the dissociation of the E-cadherin–p120-catenin complex, leading to E-cadherin proteasomal degradation, and thereby destabilizing adherens junctions in less confluent tumor cells. Our results provide a potential mechanism to explain the poor prognosis of cancer patients with high serum 90K levels.

  15. PTP-PEST targets a novel tyrosine site in p120 catenin to control epithelial cell motility and Rho GTPase activity

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    Espejo, Rosario; Jeng, Yowjiun; Paulucci-Holthauzen, Adriana; Rengifo-Cam, William; Honkus, Krysta; Anastasiadis, Panos Z.; Sastry, Sarita K.

    2014-01-01

    ABSTRACT Tyrosine phosphorylation is implicated in regulating the adherens junction protein, p120 catenin (p120), however, the mechanisms are not well defined. Here, we show, using substrate trapping, that p120 is a direct target of the protein tyrosine phosphatase, PTP-PEST, in epithelial cells. Stable shRNA knockdown of PTP-PEST in colon carcinoma cells results in an increased cytosolic pool of p120 concomitant with its enhanced tyrosine phosphorylation and decreased association with E-cadherin. Consistent with this, PTP-PEST knockdown cells exhibit increased motility, enhanced Rac1 and decreased RhoA activity on a collagen substrate. Furthermore, p120 localization is enhanced at actin-rich protrusions and lamellipodia and has an increased association with the guanine nucleotide exchange factor, VAV2, and cortactin. Exchange factor activity of VAV2 is enhanced by PTP-PEST knockdown whereas overexpression of a VAV2 C-terminal domain or DH domain mutant blocks cell motility. Analysis of point mutations identified tyrosine 335 in the N-terminal domain of p120 as the site of PTP-PEST dephosphorylation. A Y335F mutant of p120 failed to induce the ‘p120 phenotype’, interact with VAV2, stimulate cell motility or activate Rac1. Together, these data suggest that PTP-PEST affects epithelial cell motility by controlling the distribution and phosphorylation of p120 and its availability to control Rho GTPase activity. PMID:24284071

  16. 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...

  17. Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae.

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    Luo, Wen-Wei; Wang, Xin-Wei; Ma, Rui; Chi, Fang-Lu; Chen, Ping; Cong, Ning; Gu, Yu-Yan; Ren, Dong-Dong; Yang, Juan-Mei

    2018-01-01

    Notch inhibition is known to generate supernumerary hair cells (HCs) at the expense of supporting cells (SCs) in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0) with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

  18. Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae

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    Wen-wei Luo

    2018-02-01

    Full Text Available Notch inhibition is known to generate supernumerary hair cells (HCs at the expense of supporting cells (SCs in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0 with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

  19. p120-catenin mediates inflammatory responses in the skin

    DEFF Research Database (Denmark)

    Perez-Moreno, Mirna; Davis, Michael A; Wong, Ellen

    2006-01-01

    but no overt disruption in barrier function or intercellular adhesion. As the mice age, however, they display epidermal hyperplasia and chronic inflammation, typified by hair degeneration and loss of body fat. Using skin engraftments and anti-inflammatory drugs, we show that these features are not attributable...

  20. CLASP2 interacts with p120-catenin and governs microtubule dynamics at adherens junctions

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    Shahbazi, Marta N; Megias, Diego; Epifano, Carolina

    2013-01-01

    Classical cadherins and their connections with microtubules (MTs) are emerging as important determinants of cell adhesion. However, the functional relevance of such interactions and the molecular players that contribute to tissue architecture are still emerging. In this paper, we report that the ...

  1. Analysis of a Mycoplasma hominis membrane protein, P120

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Mathiesen, SL; Nyvold, Charlotte Guldborg

    1994-01-01

    The monoclonal antibody mAb 26.7D generated against a clinical isolate of Mycoplasma hominis 7488 was shown to react with a surface-exposed epitope on a 120-kDa protein (P120). The gene encoding the protein was cloned and sequenced, and the transcriptional start point was determined by primer...

  2. 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

  3. 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.

  4. P120-GAP associated with syndecan-2 to function as an active switch signal for Src upon transformation with oncogenic ras

    International Nuclear Information System (INIS)

    Huang, J.-W.; Chen, C.-L.; Chuang, N.-N.

    2005-01-01

    BALB/3T3 cells transfected with plasmids pcDNA3.1-[S-ras(Q 61 K)] of shrimp Penaeus japonicus were applied to reveal a complex of p120-GAP/syndecan-2 being highly expressed upon transformation. Of interest, most of the p120-GAP/syndecan-2 complex was localized at caveolae, a membrane microdomain enriched with caveolin-1. To confirm the molecular interaction between syndecan-2 and p120-GAP, we further purified p120-GAP protein from mouse brains by using an affinity column of HiTrap-RACK1 and expressed mouse RACK1-encoded fusion protein and mouse syndecan-2-encoded fusion protein in bacteria. We report molecular affinities exist between p120-GAP and RACK1, syndecan-2 and RACK1 as well as p120-GAP and syndecan-2. The selective affinity between p120-GAP and syndecan-2 was found to be sufficient to detach RACK1. The p120-GAP/syndecan-2 complex was demonstrated to keep Src tyrosine kinase in an activated form. On the other hand, the syndecan-2/RACK1 complex was found to have Src in an inactivated form. These data indicate that the p120-GAP/syndecan-2 complex at caveolae could provide a docking site for Src to transmit tyrosine signaling, implying that syndecan-2/p120-GAP functions as a tumor promoter upon transformation with oncogenic ras of shrimp P. japonicus

  5. STAT3 Potentiates SIAH-1 Mediated Proteasomal Degradation of β-Catenin in Human Embryonic Kidney Cells.

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    Shin, Minkyung; Yi, Eun Hee; Kim, Byung-Hak; Shin, Jae-Cheon; Park, Jung Youl; Cho, Chung-Hyun; Park, Jong-Wan; Choi, Kang-Yell; Ye, Sang-Kyu

    2016-11-30

    The β-catenin functions as an adhesion molecule and a component of the Wnt signaling pathway. In the absence of the Wnt ligand, β-catenin is constantly phosphorylated, which designates it for degradation by the APC complex. This process is one of the key regulatory mechanisms of β-catenin. The level of β-catenin is also controlled by the E3 ubiquitin protein ligase SIAH-1 via a phosphorylation-independent degradation pathway. Similar to β-catenin, STAT3 is responsible for various cellular processes, such as survival, proliferation, and differentiation. However, little is known about how these molecules work together to regulate diverse cellular processes. In this study, we investigated the regulatory relationship between STAT3 and β-catenin in HEK293T cells. To our knowledge, this is the first study to report that β-catenin-TCF-4 transcriptional activity was suppressed by phosphorylated STAT3; furthermore, STAT3 inactivation abolished this effect and elevated activated β-catenin levels. STAT3 also showed a strong interaction with SIAH-1, a regulator of active β-catenin via degradation, which stabilized SIAH-1 and increased its interaction with β-catenin. These results suggest that activated STAT3 regulates active β-catenin protein levels via stabilization of SIAH-1 and the subsequent ubiquitin-dependent proteasomal degradation of β-catenin in HEK293T cells.

  6. Beta-Catenin Stability in Breast Cancer

    National Research Council Canada - National Science Library

    Baswaran, Vijay

    1999-01-01

    .... beta-catenin also binds the adenomatous polyposis coli protein (APC). The tumor suppressor function of APC is suggested to depend in part on its ability to bind beta-catenin and to facilitate beta-catenin degradation by an unknown mechanism...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/{beta}-catenin signaling pathway in HCT116 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); Kim, Chul Young [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); College of Pharmacy, Hanyang University, Ansan 426-791 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of)

    2012-11-16

    Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/{beta}-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: Black-Right-Pointing-Pointer Gomisins J and N inhibited Wnt/{beta}-catenin signaling pathway in HCT116 cells. Black-Right-Pointing-Pointer Gomisins J and N disrupted the binding of {beta}-catenin to specific DNA sequences, TBE. Black-Right-Pointing-Pointer Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. Black-Right-Pointing-Pointer Gomisins J and N inhibited the expression of Cyc D1, a Wnt/{beta}-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/{beta}-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/{beta}-catenin signaling by disrupting the interaction between {beta}-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the {beta}-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/{beta}-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/{beta}-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

  12. 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.

  13. Correlation between E-cadherin and p120 expression in invasive ductal breast cancer with a lobular component and MRI findings.

    Science.gov (United States)

    El Sharouni, Mary-Ann; Postma, Emily L; van Diest, Paul J

    2017-12-01

    Invasive breast cancer comprises a spectrum of histological changes with purely lobular cancer on one side and purely ductal cancer on the other, with many mixed lesions in between. In a previous study, we showed that in patients with any percentage lobular component at core needle biopsy, preoperative MRI leads to the detection of clinically relevant additional findings in a substantial percentage of patients, irrespective of the percentage of the lobular component. Detection of a small lobular component may however not be reproducible among pathologists. Loss of membrane expression of E-cadherin or p120 is useful biomarkers of ILC and may therefore support a more objective diagnosis. All patients diagnosed with breast cancer containing a lobular component of any percentage between January 2008 and October 2012 were prospectively offered preoperative MRI. Clinically relevant additional findings on MRI were verified by pathology evaluation. Expression patterns of E-cadherin and p120 were evaluated by immunohistochemistry on the core needle biopsy. MRI was performed in 109 patients. The percentage of lobular component was significantly increased in cases with aberrant E-cadherin or p120 expression (both p = lobular component in the core needle of their breast cancer.

  14. 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

  15. SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Il-Rae [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Koh, Sang Seok [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333 (Korea, Republic of); Department of Functional Genomics, University of Science and Technology, Daejeon 305-333 (Korea, Republic of); Malilas, Waraporn; Srisuttee, Ratakorn; Moon, Jeong [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Choi, Young-Whan [Department of Horticultural Bioscience, Pusan National University, Miryang 627-706 (Korea, Republic of); Horio, Yoshiyuki [Department of Pharmacology, Sapporo Medical University, Sapporo 060-8556 (Japan); Oh, Sangtaek [Department of Advanced Fermentation Fusion Science and Technology, Kookmin University, Seoul 136-702 (Korea, Republic of); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [WCU, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2012-06-29

    -mediated degradation of {beta}-catenin in the cells. Finally, activation of SIRT1 inhibited the proliferation of Panc-PAUF cells by down-regulation of cyclin-D1, a target molecule of {beta}-catenin. These results suggest that SIRT1 activation may be a therapeutic strategy for treatment of pancreatic cancer cells that express PAUF via the down-regulation of {beta}-catenin.

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

    Science.gov (United States)

    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.

  17. The activity of the anti-apoptotic fragment generated by the caspase-3/p120 RasGAP stress-sensing module displays strict Akt isoform specificity.

    Science.gov (United States)

    Vanli, Güliz; Peltzer, Nieves; Dubuis, Gilles; Widmann, Christian

    2014-12-01

    The caspase-3/p120 RasGAP module acts as a stress sensor that promotes pro-survival or pro-death signaling depending on the intensity and the duration of the stressful stimuli. Partial cleavage of p120 RasGAP generates a fragment, called fragment N, which protects stressed cells by activating Akt signaling. Akt family members regulate many cellular processes including proliferation, inhibition of apoptosis and metabolism. These cellular processes are regulated by three distinct Akt isoforms: Akt1, Akt2 and Akt3. However, which of these isoforms are required for fragment N mediated protection have not been defined. In this study, we investigated the individual contribution of each isoform in fragment N-mediated cell protection against Fas ligand induced cell death. To this end, DLD1 and HCT116 isogenic cell lines lacking specific Akt isoforms were used. It was found that fragment N could activate Akt1 and Akt2 but that only the former could mediate the protective activity of the RasGAP-derived fragment. Even overexpression of Akt2 or Akt3 could not rescue the inability of fragment N to protect cells lacking Akt1. These results demonstrate a strict Akt isoform requirement for the anti-apoptotic activity of fragment N. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Protein kinase A activation enhances β-catenin transcriptional activity through nuclear localization to PML bodies.

    Directory of Open Access Journals (Sweden)

    Mei Zhang

    Full Text Available The Protein Kinase A (PKA and Wnt signaling cascades are fundamental pathways involved in cellular development and maintenance. In the osteoblast lineage, these pathways have been demonstrated functionally to be essential for the production of mineralized bone. Evidence for PKA-Wnt crosstalk has been reported both during tumorigenesis and during organogenesis, and the nature of the interaction is thought to rely on tissue and cell context. In this manuscript, we analyzed bone tumors arising from mice with activated PKA caused by mutation of the PKA regulatory subunit Prkar1a. In primary cells from these tumors, we observed relocalization of β-catenin to intranuclear punctuate structures, which were identified as PML bodies. Cellular redistribution of β-catenin could be recapitulated by pharmacologic activation of PKA. Using 3T3-E1 pre-osteoblasts as a model system, we found that PKA phosphorylation sites on β-catenin were required for nuclear re-localization. Further, β-catenin's transport to the nucleus was accompanied by an increase in canonical Wnt-dependent transcription, which also required the PKA sites. PKA-Wnt crosstalk in the cells was bi-directional, including enhanced interactions between β-catenin and the cAMP-responsive element binding protein (CREB and transcriptional crosstalk between the Wnt and PKA signaling pathways. Increases in canonical Wnt/β-catenin signaling were associated with a decrease in the activity of the non-canonical Wnt/Ror2 pathway, which has been shown to antagonize canonical Wnt signaling. Taken together, this study provides a new understanding of the complex regulation of the subcellular distribution of β-catenin and its differential protein-protein interaction that can be modulated by PKA signaling.

  19. The proto-oncogene product p120CBL and the adaptor proteins CRKL and c-CRK link c-ABL, p190BCR/ABL and p210BCR/ABL to the phosphatidylinositol-3' kinase pathway.

    Science.gov (United States)

    Sattler, M; Salgia, R; Okuda, K; Uemura, N; Durstin, M A; Pisick, E; Xu, G; Li, J L; Prasad, K V; Griffin, J D

    1996-02-15

    Chronic myelogenous leukemia (CML) and some acute lymphoblastic leukemias (ALL) are caused by the t(9;22) chromosome translocation, which produces the constitutively activated BCR/ABL tyrosine kinase. When introduced into factor dependent hematopoietic cell lines, BCR/ABL induces the tyrosine phosphorylation of many cellular proteins. One prominent BCR/ABL substrate is p120CBL, the cellular homolog of the v-Cbl oncoprotein. In an effort to understand the possible contribution of p120CBL to transformation by BCR/ABL, we looked for cellular proteins which associate with p120CBL in hematopoietic cell lines transformed by BCR/ABL. In addition to p210BCR/ABL and c-ABL, p120CBL coprecipitated with an 85 kDa phosphoprotein, which was identified as the p85 subunit of PI3K. Anti-p120CBL immunoprecipitates from BCR/ABL-transformed, but not from untransformed, cell lines contained PI3K lipid kinase activity. Interestingly, the adaptor proteins CRKL and c-CRK were also found in these complexes. In vitro binding studies indicated that the SH2 domains of CRKL and c-CRK bound directly to p120CBL, while the SH3 domains of c-CRK and CRKL bound to BCR/ABL and c-ABL. The N-terminal and the C-terminal SH2 and the SH3 domain of p85PI3K bound directly in vitro to p120CBL. The ABL-SH2, but not ABL-SH3, could also bind to p120CBL. These data suggest that BCR/ABL may induce the formation of multimeric complexes of signaling proteins which include p120CBL, PI3K, c-CRK or CRKL, c-ABL and BCR/ABL itself.

  20. 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...

  1. 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...

  2. 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 ...

  3. 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

  4. IKK and (Beta) - Catenin in Breast Cancer

    Science.gov (United States)

    2004-07-01

    TOPFLASIt + + + + . + + + + - - - - IKK( (SS/AA) +- -. - - IKKII(SS/AA) -+ + Nl’- k3 reporwr - + + + + B) 180 160 140 120 100 - U 80 60 401...2001 Vitamin D(3) promotes the differentiation of colon carcinoma cells by the induction of E-cadherin and the inhibition of beta-catenin signaling. J

  5. Application of on-line nanoLC-IT-TOF in the identification of serum β-catenin complex in mice scald model.

    Directory of Open Access Journals (Sweden)

    Cheng-cai Huang

    Full Text Available Severe burn shock remains an unresolved clinical problem with an urgent need to explore novel therapeutic treatments. Intracellular β-catenin, through interaction with other proteins, has been reported to be able to regulate the size of cutaneous wounds. Higher expression of β-catenin is associated with larger sized wounds. However, the identification of serum β-catenin complex is difficult and has been rarely reported. The exploitation of more binding partners can contribute to uncovering the exact mechanisms behind serum β-catenin mediated biological effects. Here, we describe a method that consists of immunoprecipitation, SDS-PAGE, in-gel digestion, and nanoLC coupled to LCMS-IT-TOF for the investigation of serum β-catenin complex in mice scald model. Among selected gel bands obtained from the protein gels, a total of 31 peptides were identified and sequenced with high statistical significance (p<0.01. Three proteins (alpha-2-marcoglobulin, serine protease inhibitor A3K, and serine protease inhibitor A1A were identified and validated with high reliability and high reproducibility. It was inferred that these proteins might interact with serum β-catenin, which could affect the wound healing resulting from burn shock. Our study demonstrated that the on-line coupling of nano-LC with a LCMS-IT-TOF mass spectrometer was capable of sensitive and automated characterization of the serum β-catenin complex in mice scald model.

  6. 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.

  7. 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

  8. 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

  9. 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 ...

  10. The SH3 domain-binding T cell tyrosyl phosphoprotein p120. Demonstration of its identity with the c-cbl protooncogene product and in vivo complexes with Fyn, Grb2, and phosphatidylinositol 3-kinase

    NARCIS (Netherlands)

    Fukazawa, T.; Reedquist, K. A.; Trub, T.; Soltoff, S.; Panchamoorthy, G.; Druker, B.; Cantley, L.; Shoelson, S. E.; Band, H.

    1995-01-01

    Previously, we have identified p120 as a Fyn/Lck SH3 and SH2 domain-binding protein that is tyrosine phosphorylated rapidly after T cell receptor triggering. Here, we used direct protein purification, amino acid sequence analysis, reactivity with antibodies, and two-dimensional gel analyses to

  11. 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.

  12. Axin1 up-regulated 1 accelerates stress-induced cardiomyocytes apoptosis through activating Wnt/β-catenin signaling.

    Science.gov (United States)

    Ye, Xing; Lin, Junyi; Lin, Zebin; Xue, Aimin; Li, Liliang; Zhao, Ziqin; Liu, Li; Shen, Yiwen; Cong, Bin

    2017-10-15

    Stress-induced cardiomyocyte apoptosis contributes to the pathogenesis of a variety of cardiovascular diseases, but how stress induces cardiomyocyte apoptosis remains largely unclear. The present study aims to investigate the effects of Axin1 up-regulated 1 (Axud1), a novel pro-apoptotic protein, on the cardiomyocyte survival and the underlying mechanisms. To this end, a rat model under restraint stress (RS) was established and in vitro stress-induced cardiomyocytes culture was achieved. Our data showed that Axud1 was upregulated in the rat myocardia after exposure to RS. Anti-apoptotic Bcl-2 was decreased, whereas pro-apoptotic Bax and Cleaved caspase-3 (Cc3) were increased in a time-dependent manner. The Wnt/β-catenin signaling was observed to be interestingly activated in heart undergoing RS. In addition, the treatment of norepinephrine (NE) to in vitro cardiomyocytes increased Axud1 level and induced cell apoptosis. Wnt/β-catenin signaling was consistently activated. Knockdown of Axud1 using specific siRNA blunted NE-induced cardiomyocytes apoptosis and also inactivated the Wnt/β-catenin signaling. XAV-939, an inhibitor of Wnt/β-catenin signaling, partially reversed the pro-apoptotic effect of NE. In conclusion, Axud1 accelerated stress-induced cardiomyocytes apoptosis through activation of Wnt/β-catenin signaling pathway. Our data provided novel evidence that therapeutic strategies against Axud1 or Wnt/β-catenin signaling might be promising in relation to RS-induced myocardial injury. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Stabilization of beta-catenin induces pancreas tumor formation.

    Science.gov (United States)

    Heiser, Patrick W; Cano, David A; Landsman, Limor; Kim, Grace E; Kench, James G; Klimstra, David S; Taketo, Maketo M; Biankin, Andrew V; Hebrok, Matthias

    2008-10-01

    beta-Catenin signaling within the canonical Wnt pathway is essential for pancreas development. However, the pathway is normally down-regulated in the adult organ. Increased cytoplasmic and nuclear localization of beta-catenin can be detected in nearly all human solid pseudopapillary neoplasms (SPN), a rare tumor with low malignant potential. Conversely, pancreatic ductal adenocarcinoma (PDA) accounts for the majority of pancreatic tumors and is among the leading causes of cancer death. Whereas activating mutations within beta-catenin and other members of the canonical Wnt pathway are rare, recent reports have implicated Wnt signaling in the development and progression of human PDA. Here, we sought to address the role of beta-catenin signaling in pancreas tumorigenesis. Using Cre/lox technology, we conditionally activated beta-catenin in a subset of murine pancreatic cells in vivo. Activation of beta-catenin results in the formation of large pancreatic tumors at a high frequency in adult mice. These tumors resemble human SPN based on morphologic and immunohistochemical comparisons. Interestingly, stabilization of beta-catenin blocks the formation of pancreatic intraepithelial neoplasia (PanIN) in the presence of an activating mutation in Kras that is known to predispose individuals to PDA. Instead, mice in which beta-catenin and Kras are concurrently activated develop distinct ductal neoplasms that do not resemble PanIN lesions. These results demonstrate that activation of beta-catenin is sufficient to induce pancreas tumorigenesis. Moreover, they indicate that the sequence in which oncogenic mutations are acquired has profound consequences on the phenotype of the resulting tumor.

  14. Identification of E2F1 as a positive transcriptional regulator for δ-catenin

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

  16. Connections between cadherin-catenin proteins, spindle misorientation, and cancer

    DEFF Research Database (Denmark)

    Shahbazi, Marta N; Perez-Moreno, Mirna

    2015-01-01

    Cadherin-catenin mediated adhesion is an important determinant of tissue architecture in multicellular organisms. Cancer progression and maintenance is frequently associated with loss of their expression or functional activity, which not only leads to decreased cell-cell adhesion, but also to enh......; and illustrates how alterations in cadherin-catenin levels or functional activity may render cells susceptible to transformation through the loss of their proliferation-differentiation balance....

  17. Rib fractures and death from deletion of osteoblast βcatenin in adult mice is rescued by corticosteroids.

    Science.gov (United States)

    Duan, JinZhu; Lee, Yueh; Jania, Corey; Gong, Jucheng; Rojas, Mauricio; Burk, Laurel; Willis, Monte; Homeister, Jonathon; Tilley, Stephen; Rubin, Janet; Deb, Arjun

    2013-01-01

    Ribs are primarily made of cortical bone and are necessary for chest expansion and ventilation. Rib fractures represent the most common type of non-traumatic fractures in the elderly yet few studies have focused on the biology of rib fragility. Here, we show that deletion of βcatenin in Col1a2 expressing osteoblasts of adult mice leads to aggressive osteoclastogenesis with increased serum levels of the osteoclastogenic cytokine RANKL, extensive rib resorption, multiple spontaneous rib fractures and chest wall deformities. Within days of osteoblast specific βcatenin deletion, animals die from respiratory failure with a vanishing rib cage that is unable to sustain ventilation. Increased bone resorption is also observed in the vertebrae and femur. Treatment with the bisphosphonate pamidronate delayed but did not prevent death or associated rib fractures. In contrast, administration of the glucocorticoid dexamethasone decreased serum RANKL and slowed osteoclastogenesis. Dexamethasone preserved rib structure, prevented respiratory compromise and strikingly increased survival. Our findings provide a novel model of accelerated osteoclastogenesis, where deletion of osteoblast βcatenin in adults leads to rapid development of destructive rib fractures. We demonstrate the role of βcatenin dependent mechanisms in rib fractures and suggest that glucocorticoids, by suppressing RANKL, may have a role in treating bone loss due to aggressive osteoclastogenesis.

  18. β-Catenin is critical for cerebellar foliation and lamination.

    Directory of Open Access Journals (Sweden)

    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.

  19. Mesenchymal Wnt/β-catenin signaling limits tooth number.

    Science.gov (United States)

    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.

  20. 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.

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

    Science.gov (United States)

    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.

  2. Cell-cycle-dependent three-dimensional redistribution of nuclear proteins, P 120, pKi-67, and SC 35 splicing factor, in the presence of the topoisomerase I inhibitor camptothecin.

    Science.gov (United States)

    Elias, Emmanuel; Lalun, Nathalie; Lorenzato, Marianne; Blache, Laurent; Chelidze, Pavel; O'Donohue, Marie-Françoise; Ploton, Dominique; Bobichon, Hélène

    2003-11-15

    Topoisomerase I (Topo I) is mostly known for its role in DNA relaxation, which is required for duplication and transcription. Topo I acts as a protein kinase mainly directed to the mRNA splicing factor SC35. Camptothecin is one of the specific Topo I inhibitors and is effective on the two functions of the enzyme. In this study we demonstrated that treatment of KB cells with camptothecin for only 30 min induced the 3D reorganization and redistribution of three proteins involved in the nucleus machinery, P 120, pKi-67, and SC 35, and this occurred in a cell cycle-dependent manner. Our data were obtained from confocal microscopic studies after immunolabeling, 3D reconstruction, and measurement of the nuclear components volumes. In the presence of camptothecin, P 120, which occupied the nucleolar volume, lost its reticulation and pKi-67 was redistributed within the nucleoplasm and even into the cytoplasm. Finally, for SC 35 the fusion of its dots into bigger volumes was observed specifically during the G1 phase. Variations of volumes were also observed for the nucleolus and for the nucleus. These results pointed out that, depending on the cell cycle phase, Topo I functions were selective toward the three different proteins.

  3. 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...

  4. Regulation of Wnt/β-catenin signaling by posttranslational modifications

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  6. 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

    The canonical Wnt signalling pathway plays a critical role in development and disease. The key player of the pathway is β-catenin. Its activity is mainly regulated by the destruction complex consisting of APC, Axin and GSK3. In the nucleus, the complex formation of β-catenin and TCF initiates target gene expression. Our study provides a comprehensive analysis of the role of nucleo-cytoplasmic shuttling of APC, Axin, and GSK3 and the inactivation of β-catenin by the destruction complex in Wnt/β-catenin signalling. We address the following questions: Can nucleo-cytoplasmic shuttling of APC, Axin and GSK3 increase the [β-catenin/TCF] concentration? And, how is the [β-catenin/TCF] concentration influenced by phosphorylation and subsequent degradation of nuclear β-catenin? Based on experimental findings, we develop a compartmental model and conduct several simulation experiments. Our analysis reveals the following key findings: 1) nucleo-cytoplasmic shuttling of β-catenin and its antagonists can yield a spatial separation between the said proteins, which results in a breakdown of β-catenin degradation, followed by an accumulation of β-catenin and hence leads to an increase of the [β-catenin/TCF] concentration. Our results strongly suggest that Wnt signalling can benefit from nucleo-cytoplasmic shuttling of APC, Axin and GSK3, although they are in general β-catenin antagonising proteins. 2) The total robustness of the [β-catenin/TCF] output is closely linked to its absolute concentration levels. We demonstrate that the compartmental separation of β-catenin and the destruction complex does not only lead to a maximization, but additionally to an increased robustness of [β-catenin/TCF] signalling against perturbations in the cellular environment. 3) A nuclear accumulation of the destruction complex renders the pathway robust against fluctuations in Wnt signalling and against changes in the compartmental distribution of β-catenin. 4) Elucidating the impact of

  7. 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.

  8. Activation of β-catenin signaling in androgen receptor-negative prostate cancer cells.

    Science.gov (United States)

    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.

  9. 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

  10. Lysosomal trafficking of {beta}-catenin induced by the tea polyphenol epigallocatechin-3-gallate

    Energy Technology Data Exchange (ETDEWEB)

    Dashwood, Wan-Mohaiza [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Carter, Orianna [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Al-Fageeh, Mohamed [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Li, Qingjie [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States); Dashwood, Roderick H. [Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331-6512 (United States)]. E-mail: Rod.Dashwood@oregonstate.edu

    2005-12-11

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

  11. The Role of b-Catenin in Mammary Gland Carcinogenesis

    Science.gov (United States)

    2002-03-01

    Wetering, M., Cavallo, R., Dooijes, D., van Beest , M., van Es, J., Loureiro, J., Ypma, A., hursh, D., Jones, T., Bejsovec, A., Peifer, M., Mortin, M...Transduction Lab - domain of /3-catenin. oratories) and anti-KT3 (Babco) were used as primary Elevated levels of fl-catenin were recently observed in antibodies...1988). Cell, 55, 619 -625. Kolligs FT, Hu G, Dang CV and Fearon ER. (1999). Mol. van de Wetering M, Cavallo R, Dooijes D, van Beest M, van Cell. Biol

  12. 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 ...

  13. 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...

  14. 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.

  15. Discovery of novel small molecule activators of β-catenin signaling.

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. 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.

  18. Protein kinase C ϵ stabilizes β-catenin and regulates its subcellular localization in podocytes.

    Science.gov (United States)

    Duong, Michelle; Yu, Xuejiao; Teng, Beina; Schroder, Patricia; Haller, Hermann; Eschenburg, Susanne; Schiffer, Mario

    2017-07-21

    Kidney disease has been linked to dysregulated signaling via PKC in kidney cells such as podocytes. PKCα is a conventional isoform of PKC and a well-known binding partner of β-catenin, which promotes its degradation. β-Catenin is the main effector of the canonical Wnt pathway and is critical in cell adhesion. However, whether other PKC isoforms interact with β-catenin has not been studied systematically. Here we demonstrate that PKCϵ-deficient mice, which develop proteinuria and glomerulosclerosis, display lower β-catenin expression compared with PKC wild-type mice, consistent with an altered phenotype of podocytes in culture. Remarkably, β-catenin showed a reversed subcellular localization pattern: Although β-catenin exhibited a perinuclear pattern in undifferentiated wild-type cells, it predominantly localized to the nucleus in PKCϵ knockout cells. Phorbol 12-myristate 13-acetate stimulation of both cell types revealed that PKCϵ positively regulates β-catenin expression and stabilization in a glycogen synthase kinase 3β-independent manner. Further, β-catenin overexpression in PKCϵ-deficient podocytes could restore the wild-type phenotype, similar to rescue with a PKCϵ construct. This effect was mediated by up-regulation of P-cadherin and the β-catenin downstream target fascin1. Zebrafish studies indicated three PKCϵ-specific phosphorylation sites in β-catenin that are required for full β-catenin function. Co-immunoprecipitation and pulldown assays confirmed PKCϵ and β-catenin as binding partners and revealed that ablation of the three PKCϵ phosphorylation sites weakens their interaction. In summary, we identified a novel pathway for regulation of β-catenin levels and define PKCϵ as an important β-catenin interaction partner and signaling opponent of other PKC isoforms in podocytes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. WNT/β-Catenin Signaling in Vertebrate Eye Development

    Czech Academy of Sciences Publication Activity Database

    Fujimura, Naoko

    2016-01-01

    Roč. 4, November (2016), č. článku 138. ISSN 2296-634X R&D Projects: GA MŠk(CZ) LQ1604 Institutional support: RVO:68378050 Keywords : retina * WNT * b-catenin * development * differentiation Subject RIV: EB - Genetics ; Molecular Biology

  20. Murrayafoline A attenuates the Wnt/{beta}-catenin pathway by promoting the degradation of intracellular {beta}-catenin proteins

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyuk; Gwak, Jungsug; Cho, Munju; Ryu, Min-Jung [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Lee, Jee-Hyun; Kim, Sang Kyum; Kim, Young Ho [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gye Won [Department of Pharmaceutical Engineering, Konyang University, Nonsan 320-711 (Korea, Republic of); Yun, Mi-Young [Department of Beauty Health Care, Daejeon University, Daejeon 305-764 (Korea, Republic of); Cuong, Nguyen Manh [Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Gyu-Yong, E-mail: gysong@cnu.ac.kr [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

    2010-01-01

    Molecular lesions in Wnt/{beta}-catenin signaling and subsequent up-regulation of {beta}-catenin response transcription (CRT) occur frequently during the development of colon cancer. To identify small molecules that suppress CRT, we screened natural compounds in a cell-based assay for detection of TOPFalsh reporter activity. Murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa, antagonized CRT that was stimulated by Wnt3a-conditioned medium (Wnt3a-CM) or LiCl, an inhibitor of glycogen synthase kinase-3{beta} (GSK-3{beta}), and promoted the degradation of intracellular {beta}-catenin without altering its N-terminal phosphorylation at the Ser33/37 residues, marking it for proteasomal degradation, or the expression of Siah-1, an E3 ubiquitin ligase. Murrayafoline A repressed the expression of cyclin D1 and c-myc, which is known {beta}-catenin/T cell factor (TCF)-dependent genes and thus inhibited the proliferation of various colon cancer cells. These findings indicate that murrayafoline A may be a potential chemotherapeutic agent for use in the treatment of colon cancer.

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

    Science.gov (United States)

    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.

  2. 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

  3. 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.

  4. Activation of Beta-Catenin Signaling in Androgen Receptor–Negative Prostate Cancer Cells

    Science.gov (United States)

    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.

    2012-01-01

    Purpose To study Wnt/beta-catenin in castrate-resistant prostate cancer (CRPC) and understand its function independently of the beta-catenin–androgen receptor (AR) interaction. Experimental Design We performed beta-catenin immunocytochemical analysis, evaluated TOP-flash reporter activity (a reporter of beta-catenin–mediated transcription), and sequenced the beta-catenin gene in MDA PCa 118a, MDA PCa 118b, MDA PCa 2b, and PC-3 prostate cancer (PCa) cells. We knocked down beta-catenin in AR-negative MDA PCa 118b cells and performed comparative gene-array analysis. We also immunohistochemically analyzed beta-catenin and AR in 27 bone metastases of human CRPCs. Results Beta-catenin nuclear accumulation and TOP-flash reporter activity were high in MDA PCa 118b but not in MDA PCa 2b or PC-3 cells. MDA PCa 118a and 118b cells carry a mutated beta-catenin at codon 32 (D32G). Ten genes were expressed differently (false discovery rate, 0.05) in MDA PCa 118b cells with downregulated beta-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 beta-catenin. Finally, we found nuclear localization of beta-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/beta-catenin signaling. Conclusion We identified a previously unknown downstream target of beta-catenin, HAS2, in PCa, and found that high beta-catenin nuclear localization and low or no AR expression may define a subpopulation of men with bone-metastatic PCa. These findings may guide physicians in managing these patients. PMID:22298898

  5. 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.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    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.

  9. Constitutive β-catenin activation in osteoblasts impairs terminal osteoblast differentiation and bone quality

    Energy Technology Data Exchange (ETDEWEB)

    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

  10. Axin-mediated CKI phosphorylation of beta-catenin at Ser 45

    DEFF Research Database (Denmark)

    Amit, Sharon; Hatzubai, Ada; Birman, Yaara

    2002-01-01

    The Wnt pathway controls numerous developmental processes via the beta-catenin-TCF/LEF transcription complex. Deregulation of the pathway results in the aberrant accumulation of beta-catenin in the nucleus, often leading to cancer. Normally, cytoplasmic beta-catenin associates with APC and axin...... and is continuously phosphorylated by GSK-3beta, marking it for proteasomal degradation. Wnt signaling is considered to prevent GSK-3beta from phosphorylating beta-catenin, thus causing its stabilization. However, the Wnt mechanism of action has not been resolved. Here we study the regulation of beta......-catenin phosphorylation and degradation by the Wnt pathway. Using mass spectrometry and phosphopeptide-specific antibodies, we show that a complex of axin and casein kinase I (CKI) induces beta-catenin phosphorylation at a single site: serine 45 (S45). Immunopurified axin and recombinant CKI phosphorylate beta...

  11. 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.

  12. 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.

  13. Expression of β-catenin protein in hepatocellular carcinoma and its relationship with alpha-fetoprotein.

    Science.gov (United States)

    Ren, Ya-Jun; Huang, Tao; Yu, Hong-Lu; Zhang, Li; He, Qian-Jin; Xiong, Zhi-Fan; Peng, Hua

    2016-12-01

    This study aimed to investigate the expression of β-catenin in hepatocellular carcinoma (HCC) tissues and its relationship with α-fetoprotein (AFP) in HCC. Immunohistochemistry was used to determine the expression of β-catenin in normal liver tissues (n=10), liver cirrhosis tissues (n=20), and primary HCC tissues (n=60). The relationship between β-catenin expression and clinical parameters of HCC was investigated. Real-time PCR and Western blotting were used to detect the mRNA and protein expression levels of β-catenin in the liver cancer cell line SMMC-7721 transfected with a plasmid encoding AFP, and also the mRNA and protein expression levels of β-catenin were measured in the liver cancer cell line Huh7 before and after the transfection with AFP shRNA plasmids. The results showed that β-catenin was only expressed on the cell membrane in normal liver tissues. Its localization to the cytoplasm and nucleus of cells was observed in a small proportion of cirrhotic tissues or adjacent HCC tissues, and such ectopic expression of β-catenin was predominant in HCC tissues. The abnormal expression of β-catenin was correlated with serum AFP levels, cancer cell differentiation and vascular invasion (P<0.05). Additionally, the increased expression of AFP resulted in the upregulation of β-catenin mRNA and protein levels, while knockdown of AFP with AFP shRNA led to significantly decreased β-catenin mRNA and protein levels (P<0.05). It was suggested that the abnormal expression of β-catenin is implicated in hepatic carcinogenesis and development. AFP can lead to increased expression of β-catenin, which may account for the poor prognosis of AFP-associated HCC patients.

  14. Wnt/β-catenin signaling: new (and old) players and new insights

    OpenAIRE

    Huang, He; He, Xi

    2008-01-01

    Wnt/β-catenin signaling has central roles in embryogenesis and human diseases including cancer. A central scheme of the Wnt pathway is to stabilize the transcription coactivator β-catenin by preventing its phosphorylation-dependent degradation. Significant progress has been made towards the understanding of this critical regulatory pathway, including the protein complex that promotes β-catenin phosphorylation-degradation, and the mechanism by which the extracellular Wnt ligand engages cell su...

  15. A positive role of cadherin in Wnt/β-catenin signalling during epithelial-mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    Sara Howard

    Full Text Available The Wnt/β-catenin signalling pathway shares a key component, β-catenin, with the cadherin-based adhesion system. The signalling function of β-catenin is conferred by a soluble cytoplasmic pool that is unstable in the absence of a Wnt signal, whilst the adhesion function is based on a cadherin-bound, stable pool at the membrane. The cadherin complex is dynamic, allowing for cell-cell rearrangements such as epithelial-mesenchymal transition (EMT, where the complex turns over through internalisation. Potential interplay between the two pools remains poorly understood, but cadherins are generally considered negative regulators of Wnt signalling because they sequester cytoplasmic β-catenin. Here we explore how cellular changes at EMT affect the signalling capacity of β-catenin using two models of EMT: hepatocyte growth factor (HGF treatment of MDCK cells, and gastrulation in embryonic development. We show that EMT not only provides a pool of signalling-competent β-catenin following internalisation of cadherin, but also significantly facilitates activation of the Wnt pathway in response to both Wnt signals and exogenous β-catenin. We further demonstrate that availability of β-catenin in the cytoplasm does not necessarily correlate with Wnt/β-catenin pathway activity, since blocking endocytosis or depleting endogenous cadherin abolishes pathway activation despite the presence of β-catenin in the cytoplasm. Lastly we present data suggesting that cadherins are required for augmented activation of the Wnt/β-catenin pathway in vivo. This suggests that cadherins play a crucial role in β-catenin-dependent transcription.

  16. Wnt/β-catenin signaling activates nephronectin expression in osteoblasts

    International Nuclear Information System (INIS)

    Ikehata, Mikiko; Yamada, Atsushi; Morimura, Naoko; Itose, Masakatsu; Suzawa, Tetsuo; Shirota, Tatsuo; Chikazu, Daichi; Kamijo, Ryutaro

    2017-01-01

    Nephronectin (Npnt), an extracellular matrix protein, is considered to play critical roles as an adhesion molecule in the development and functions of various organs and tissues, such as the kidneys and bone. In the present study, we found that Wnt3a strongly enhanced Npnt mRNA expression in osteoblast-like MC3T3-E1 cells, while it also induced an increase in Npnt gene expression in both time- and dose-dependent manners via the Wnt/β-catenin signaling pathway. These results suggest novel mechanisms for Wnt3a-induced osteoblast proliferation and cell survival via Npnt gene expression. - Highlights: • Wnt3a enhances nephronectin gene expression. • Nephronectin gene induction by Wnt3a is occurred by time- and dose-dependent manner. • Expression of nephronectin is regulated via β-catenin activation.

  17. Impact of nanostructured surfaces on endothelial β-catenin signaling

    International Nuclear Information System (INIS)

    Schernthaner, M.

    2013-01-01

    In this thesis, we set out to investigate the influence of differently structured polyethylene terephtalate (PET) surfaces on human microvascular endothelial cells (HMEC). First, we tested so called ripples with a periodicity of 300 nm and second, wall structures with a periodicity of 1.5 µm. both generated by laser irradiation of PET substrates. We investigated cell adhesion and orientation by electron microscopy and determined cell proliferation levels. Endothelial proliferation is controlled by the junctional protein β-catenin, which translocates to the nucleus to activate target gene expression when released from is normal localization in cell-cell contacts. We observed that β-catenin translocates to the nucleus of endothelial cells grown on both types of structured substrates. However, the expression levels of the target gene cyclin D1 were enhanced in cells grown on ripples only. The use of different tyrosine kinase inhibitors revealed Src and Abl kinases as upstream signaling elements of β-catenin-mediated cell proliferation on ripples, while Src was found not involved in cell proliferation on walls. Since Src activation is strongly linked to Ca 2+ signaling, we tested for differences in store-operated Ca 2+ -entry (SOCE) and mechanically induced Ca 2+ -entry. Cells grown on ripples displayed significantly enhanced SOCE compared to cells grown on walls. Moreover, SOCE and shear-induced Ca 2+ -entry showed clear gadolinium (Gd 3+ ) sensitivity in cells grown on ripples only. Taken together, our results demonstrated that both structures induce endothelial β-catenin signaling by enhanced tyrosine phosphorylation leading to increased cell proliferation. The signaling process on ripples further involves Src activation and SOCE signaling. The proliferation enhancing features of the nanostructured PET substrates investigated in this thesis might be used for tissue engineering strategies.(author) [de

  18. 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.

  19. Expression of delta-catenin is associated with progression of human astrocytoma

    International Nuclear Information System (INIS)

    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

  20. 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

  1. Overexpression of α-catenin increases osteoblastic differentiation in mouse mesenchymal C3H10T1/2 cells

    International Nuclear Information System (INIS)

    Kim, Dohee; Yang, Jae-Yeon; Shin, Chan Soo

    2009-01-01

    α- and β-Catenin link cadherins to the actin-based cytoskeleton at adherens junctions and regulate cell-cell adhesion. Although roles of cadherins and canonical Wnt-/β-catenin-signaling in osteoblastic differentiation have been extensively studied, the role of α-catenin is not known. Murine embryonic mesenchymal stem cells, C3H10T1/2 cells, were transduced with retrovirus encoding α-catenin (MSCV-α-catenin-HA-GFP). In the presence of Wnt-3A conditioned medium or osteogenic medium (β-glycerol phosphate and ascorbic acid), cells overexpressing α-catenin showed enhanced osteoblastic differentiation as measured by alkaline phosphatase (ALP) staining and ALP activity assay compared to cells transduced with empty virus (MSCV-GFP). In addition, mRNA expression of osteocalcin and Runx2 was significantly increased compared to control. Cell aggregation assay revealed that α-catenin overexpression has significantly increased cell-cell aggregation. However, cellular β-catenin levels (total, cytoplasmic-nuclear ratio) and β-catenin-TCF/LEF transcriptional activity did not change by overexpression of α-catenin. Knock-down of α-catenin using siRNA decreased osteoblastic differentiation as measured by ALP assay. These results suggest that α-catenin overexpression increases osteoblastic differentiation by increasing cell-cell adhesion rather than Wnt-/β-catenin-signaling.

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

    Directory of Open Access Journals (Sweden)

    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

  3. CYP2S1 depletion enhances colorectal cell proliferation is associated with PGE2-mediated activation of β-catenin signaling

    International Nuclear Information System (INIS)

    Yang, Chao; Li, Changyuan; Li, Minle; Tong, Xuemei; Hu, Xiaowen; Yang, Xuhan; Yan, Xiaomei; He, Lin; Wan, Chunling

    2015-01-01

    Colorectal epithelial cancer is one of the most common cancers in the world and its 5-year survival rate is still relatively low. Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in the oxidative metabolism of a wide range of xenobiotics, including (pro-)carcinogens and endogenous compounds. Although CYP2S1, a member of CYP family, strongly expressed in many extrahepatic tissues, the role of CYP2S1 in cancer remains unclear. To investigate whether CYP2S1 involves in colorectal carcinogenesis, cell proliferation was analyzed in HCT116 cells depleted of CYP2S1 using small hairpin interfering RNA. Our data show that CYP2S1 knockdown promotes cell proliferation through increasing the level of endogenous prostaglandin E2(PGE2). PGE2, in turn, reduces phosphorylation of β-catenin and activates β-catenin signaling, which contributes to the cell proliferation. Furthermore, CYP2S1 knockdown increase tumor growth in xenograft mouse model. In brief, these results demonstrate that CYP2S1 regulates colorectal cancer growth through associated with PGE2-mediated activation of β-catenin signaling. - Highlights: • Knockdown of CYP2S1 expression improve HCT116 cell proliferation in vitro and in vivo. • Elevate PGE2 production in CYP2S1 knockdown cell is associated with its proliferation. • Elevate PGE2 level in CYP2S1 knockdown cells enhance β-catenin accumulation. • β-catenin activate TCF/LEF and target gene expression thus promote cell proliferation

  4. β-Catenin/POU5F1/SOX2 transcription factor complex mediates IGF-I receptor signaling and predicts poor prognosis in lung adenocarcinoma.

    Science.gov (United States)

    Xu, Chuan; Xie, Dan; Yu, Shi-Cang; Yang, Xiao-Jun; He, Li-Ru; Yang, Jing; Ping, Yi-Fang; Wang, Bin; Yang, Lang; Xu, Sen-Lin; Cui, Wei; Wang, Qing-Liang; Fu, Wen-Juan; Liu, Qing; Qian, Cheng; Cui, You-Hong; Rich, Jeremy N; Kung, Hsiang-Fu; Zhang, Xia; Bian, Xiu-Wu

    2013-05-15

    Cancer stem-like cells (CSLC) are crucial in tumor initiation and progression; however, the underlying mechanism for the self-renewal of cancer cells remains undefined. In the study, immunohistochemical analysis of specimens freshly excised from patients with lung adenocarcinoma showed that high expression of insulin-like growth factor I receptor (IGF-IR) in lung adenocarcinoma cells was positively correlated with the expressions of cancer stem cell markers CD133 and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). IGF-IR activation enhanced POU class 5 homeobox 1 (POU5F1) expression on human lung adenocarcinoma stem-like cells (LACSLC) through PI3K/AKT/GSK3β/β-catenin cascade. POU5F1 could form a novel complex with β-catenin and SOX2 to bind Nanog promoter for transcription to maintain self-renewal of LACSLCs, which was dependent on the functional IGF-IR. Genetic and pharmacologic inhibition of IGF-IR abrogated LACSLC capabilities for self-renewal and tumorigenicity in vitro. In an in vivo xenograft tumor model, knockdown of either IGF-IR or POU5F1 impeded tumorigenic potentials of LACSLCs. By analyzing pathologic specimens excised from 200 patients with lung adenocarcinoma, we found that colocalization of highly expressed IGF-IR with β-catenin and POU5F1 predicted poor prognosis. Taken together, we show that IGF-IR-mediated POU5F1 expression to form a complex with β-catenin and SOX2 is crucial for the self-renewal and oncogenic potentials of LACSLCs, and the integrative clinical detection of the expressions of IGF-IR, β-catenin, and POU5F1 is indicatory for predicting prognosis in the patients of lung adenocarcinoma. ©2013 AACR.

  5. CYP2S1 depletion enhances colorectal cell proliferation is associated with PGE2-mediated activation of β-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chao [Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030 (China); College of Life Science, Anhui Normal University, Wuhu 241000, Anhui (China); Li, Changyuan [College of Life Science, Anhui Normal University, Wuhu 241000, Anhui (China); Li, Minle; Tong, Xuemei [Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Hu, Xiaowen; Yang, Xuhan [Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030 (China); Yan, Xiaomei [School of Life Sciences & Biotechnology, Shanghai JiaoTong University, Shanghai 200240 (China); He, Lin, E-mail: helinhelin@gmail.com [Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030 (China); Wan, Chunling, E-mail: clwan@sjtu.edu.cn [Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030 (China)

    2015-02-15

    Colorectal epithelial cancer is one of the most common cancers in the world and its 5-year survival rate is still relatively low. Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in the oxidative metabolism of a wide range of xenobiotics, including (pro-)carcinogens and endogenous compounds. Although CYP2S1, a member of CYP family, strongly expressed in many extrahepatic tissues, the role of CYP2S1 in cancer remains unclear. To investigate whether CYP2S1 involves in colorectal carcinogenesis, cell proliferation was analyzed in HCT116 cells depleted of CYP2S1 using small hairpin interfering RNA. Our data show that CYP2S1 knockdown promotes cell proliferation through increasing the level of endogenous prostaglandin E2(PGE2). PGE2, in turn, reduces phosphorylation of β-catenin and activates β-catenin signaling, which contributes to the cell proliferation. Furthermore, CYP2S1 knockdown increase tumor growth in xenograft mouse model. In brief, these results demonstrate that CYP2S1 regulates colorectal cancer growth through associated with PGE2-mediated activation of β-catenin signaling. - Highlights: • Knockdown of CYP2S1 expression improve HCT116 cell proliferation in vitro and in vivo. • Elevate PGE2 production in CYP2S1 knockdown cell is associated with its proliferation. • Elevate PGE2 level in CYP2S1 knockdown cells enhance β-catenin accumulation. • β-catenin activate TCF/LEF and target gene expression thus promote cell proliferation.

  6. Wnt/β-Catenin Signaling Activation beyond Robust Nuclear β-Catenin Accumulation in Nondysplastic Barrett’s Esophagus: Regulation via Dickkopf-1

    Directory of Open Access Journals (Sweden)

    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.

  7. 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...

  8. The expression and mutation of β-catenin in colorectal traditional serrated adenomas

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. 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

  11. Canonical Wnt/β-catenin signalling is essential for optic cup formation.

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. Cftr Modulates Wnt/β-Catenin Signaling and Stem Cell Proliferation in Murine Intestine

    Directory of Open Access Journals (Sweden)

    Ashlee M. Strubberg

    2018-01-01

    Conclusions: CF intestine shows increased ISC proliferation and Wnt/β-catenin signaling. Loss of Cftr increases pHi in ISCs, which stabilizes the plasma membrane association of the Wnt transducer Dvl, likely facilitating Wnt/β-catenin signaling. Absence of Cftr-dependent suppression of ISC proliferation in the CF intestine may contribute to increased risk for intestinal tumors.

  14. Cullin4B/E3-ubiquitin ligase negatively regulates β-catenin

    Indian Academy of Sciences (India)

    -catenin is the key transducer of Wingless-type MMTV integration site family member (Wnt) signalling, upregulation of which is the cause of cancer of the colon and other tissues. In the absence of Wnt signals, -catenin is targeted to ubiquitin–proteasome-mediated degradation. Here we present the functional ...

  15. 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

  16. 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

  17. 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

  18. 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.

  19. β-catenin functions pleiotropically in differentiation and tumorigenesis in mouse embryo-derived stem cells.

    Directory of Open Access Journals (Sweden)

    Noriko Okumura

    Full Text Available The canonical Wnt/β-catenin signaling pathway plays a crucial role in the maintenance of the balance between proliferation and differentiation throughout embryogenesis and tissue homeostasis. β-Catenin, encoded by the Ctnnb1 gene, mediates an intracellular signaling cascade activated by Wnt. It also plays an important role in the maintenance of various types of stem cells including adult stem cells and cancer stem cells. However, it is unclear if β-catenin is required for the derivation of mouse embryo-derived stem cells. Here, we established β-catenin-deficient (β-cat(Δ/Δ mouse embryo-derived stem cells and showed that β-catenin is not essential for acquiring self-renewal potential in the derivation of mouse embryonic stem cells (ESCs. However, teratomas formed from embryo-derived β-cat(Δ/Δ ESCs were immature germ cell tumors without multilineage differentiated cell types. Re-expression of functional β-catenin eliminated their neoplastic, transformed phenotype and restored pluripotency, thereby rescuing the mutant ESCs. Our findings demonstrate that β-catenin has pleiotropic effects in ESCs; it is required for the differentiation of ESCs and prevents them from acquiring tumorigenic character. These results highlight β-catenin as the gatekeeper in differentiation and tumorigenesis in ESCs.

  20. Over-expression of β-catenin is associated with high grade of ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate abnormalities of β-catenin protein expression, subcellular ... Patients and methods: Forty prostate cancer specimens, obtained from patients with different stages ... Conclusions: We concluded that changes in expression and cell distribution of β-catenin correlated ... HOW TO USE AJOL.

  1. β-Catenin signaling regulates temporally discrete phases of anterior taste bud development

    Science.gov (United States)

    Thirumangalathu, Shoba; Barlow, Linda A.

    2015-01-01

    The sense of taste is mediated by multicellular taste buds located within taste papillae on the tongue. In mice, individual taste buds reside in fungiform papillae, which develop at mid-gestation as epithelial placodes in the anterior tongue. Taste placodes comprise taste bud precursor cells, which express the secreted factor sonic hedgehog (Shh) and give rise to taste bud cells that differentiate around birth. We showed previously that epithelial activation of β-catenin is the primary inductive signal for taste placode formation, followed by taste papilla morphogenesis and taste bud differentiation, but the degree to which these later elements were direct or indirect consequences of β-catenin signaling was not explored. Here, we define discrete spatiotemporal functions of β-catenin in fungiform taste bud development. Specifically, we show that early epithelial activation of β-catenin, before taste placodes form, diverts lingual epithelial cells from a taste bud fate. By contrast, β-catenin activation a day later within Shh+ placodes, expands taste bud precursors directly, but enlarges papillae indirectly. Further, placodal activation of β-catenin drives precocious differentiation of Type I glial-like taste cells, but not other taste cell types. Later activation of β-catenin within Shh+ precursors during papilla morphogenesis also expands taste bud precursors and accelerates Type I cell differentiation, but papilla size is no longer enhanced. Finally, although Shh regulates taste placode patterning, we find that it is dispensable for the accelerated Type I cell differentiation induced by β-catenin. PMID:26525674

  2. A Glimpse of the Pathogenetic Mechanisms of Wnt/β-Catenin Signaling in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2013-01-01

    Full Text Available The Wnt family of proteins belongs to a group of secreted lipid-modified glycoproteins with highly conserved cysteine residues. Prior results indicate that Wnt/β-catenin signaling plays a prominent role in cell differentiation, adhesion, survival, and apoptosis and is involved in organ development, tumorigenesis, and tissue fibrosis, among other functions. Accumulating evidence has suggested that Wnt/β-catenin exhibits a pivotal function in the progression of diabetic nephropathy (DN. In this review, we focused on discussing the dual role of Wnt/β-catenin in apoptosis and epithelial mesenchymal transition (EMT formation of mesangial cells. Moreover, we also elucidated the effect of Wnt/β-catenin in podocyte dysfunction, tubular EMT formation, and renal fibrosis under DN conditions. In addition, the molecular mechanisms involved in this process are introduced. This information provides a novel molecular target of Wnt/β-catenin for the protection of kidney damage and in delay of the progression of DN.

  3. Aberrant membranous expression of β-catenin predicts poor prognosis in patients with craniopharyngioma.

    Science.gov (United States)

    Li, Zongping; Xu, Jianguo; Huang, Siqing; You, Chao

    2015-12-01

    The objective of this study is to investigate β-catenin expression in craniopharyngioma patients and determine its significance in predicting the prognosis of this disease. Fifty craniopharyngioma patients were enrolled in this study. Expression of β-catenin in tumor specimens collected from these patients was examined through immunostaining. In addition, mutation of exon 3 in the β-catenin gene, CTNNB1, was analyzed using polymerase chain reaction, denaturing high-pressure liquid chromatography, and DNA sequencing. Based on these results, we explored the association between membranous β-catenin expression, clinical and pathologic characteristics, and prognoses in these patients. Of all craniopharyngioma specimens, 31 (62.0%) had preserved membranous β-catenin expression, whereas the remaining 19 specimens (38.0%) displayed aberrant expression. Statistical analysis showed a significant correlation between aberrant membranous β-catenin expression and CTNNB1 exon 3 mutation, as well as between aberrant membranous β-catenin expression and the histopathologic type of craniopharyngioma and type of resection in our patient population. Furthermore, aberrant membranous β-catenin expression was found to be associated with poor patient survival. Results of Kaplan-Meier survival analysis and Cox regression analysis further confirmed this finding. In conclusion, our study demonstrated that aberrant membranous β-catenin expression was significantly correlated with poor survival in patients with craniopharyngioma. This raises the possibility for use of aberrant membranous β-catenin expression as an independent risk factor in predicting the prognosis of this disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. GSK3β and β-Catenin Modulate Radiation Cytotoxicity in Pancreatic Cancer

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    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 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.

  7. A protein knockdown strategy to study the function of β-catenin in tumorigenesis

    Directory of Open Access Journals (Sweden)

    Zhou Pengbo

    2003-09-01

    Full Text Available Abstract Background The Wnt signaling pathway plays critical roles in cell proliferation and cell fate determination at many stages of development. A critical downstream target of Wnt signaling is the cytosolic β-catenin, which is stabilized upon Wnt activation and promotes transcription of a variety of target genes including c-myc and cyclin D. Aberrant Wnt signaling, which results from mutations of either β-catenin or adenomatous polyposis coli (APC, renders β-catenin resistant to degradation, and has been associated with multiple types of human cancers. Results A protein knockdown strategy was designed to reduce the cytosolic β-catenin levels through accelerating its turnover rate. By engineering a chimeric protein with the β-catenin binding domain of E-cadherin fused to βTrCP ubiquitin-protein ligase, the stable β-catenin mutant was recruited to the cellular SCF (Skp1, Cullin 1, and F-box-containing substrate receptor ubiquitination machinery for ubiquitination and degradation. The DLD1 colon cancer cells express wild type β-catenin at abnormally high levels due to loss of APC. Remarkably, conditional expression of βTrCP-E-cadherin under the control of a tetracycline-repressive promoter in DLD1 cells selectively knocked down the cytosolic, but not membrane-associated subpopulation of β-catenin. As a result, DLD1 cells were impaired in their growth and clonogenic ability in vitro, and lost their tumorigenic potential in nude mice. Conclusion We have designed a novel approach to induce degradation of stabilized/mutated β-catenin. Our results suggest that a high concentration of cytoplasmic β-catenin is critical for the growth of colorectal tumor cells. The protein knockdown strategy can be utilized not only as a novel method to dissect the role of oncoproteins in tumorigenesis, but also as a unique tool to delineate the function of a subpopulation of proteins localized to a specific subcellular compartment.

  8. Wnt/β-Catenin Signaling during Cardiac Development and Repair

    Directory of Open Access Journals (Sweden)

    Jan W. Buikema

    2014-05-01

    Full Text Available Active Wnt/β-catenin signaling is essential for proper cardiac specification, progenitor expansion and myocardial growth. During development, the mass of the embryonic heart increases multiple times to achieve the dimensions of adult ventricular chambers. Cell division in the embryonic heart is fairly present, whereas cell turnover in the adult myocardium is extremely low. Understanding of embryonic cardiomyocyte cell-replication, therefore, could improve strategies for cardiac regenerative therapeutics. Here, we review which role Wnt signaling plays in cardiac development and highlight a selection of attempts that have been made to modulate Wnt signaling after cardiac ischemic injury to improve cardiac function and reduce infarct size.

  9. 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

  10. Phytochemicals attenuating aberrant activation of β-catenin in cancer cells.

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

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

    International Nuclear Information System (INIS)

    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.

  13. 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.

  14. The role and dynamics of β-catenin in precondition induced neuroprotection after traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Gali Umschweif

    Full Text Available Preconditioning via heat acclimation (34°C 30 d results in neuroprotection from traumatic brain injury due to constitutive as well as dynamic changes triggered by the trauma. Among these changes is Akt phosphorylation, which decreases apoptosis and induces HIF1α. In the present study we investigated the Akt downstream GSK3β/β-catenin pathway and focused on post injury alternations of β catenin and its impact on the cellular response in preconditioned heat acclimated mice. We found that the reduction in motor disability is accompanied with attenuation of depressive like behavior in heat acclimated mice that correlates with the GSK3β phosphorylation state. Concomitantly, a robust β catenin phosphorylation is not followed by its degradation, or by reduced nuclear accumulation. Enhanced tyrosine phosphorylation of β catenin in the injured area weakens the β catenin-N cadherin complex. Membrane β catenin is transiently reduced in heat acclimated mice and its recovery 7 days post TBI is accompanied by induction of the synaptic marker synaptophysin. We suggest a set of cellular events following traumatic brain injury in heat acclimated mice that causes β catenin to participate in cell-cell adhesion alternations rather than in Wnt signaling. These events may contribute to synaptogenesis and the improved motor and cognitive abilities seen heat acclimated mice after traumatic brain injury.

  15. Wnt/β-catenin pathway regulates ABCB1 transcription in chronic myeloid leukemia

    International Nuclear Information System (INIS)

    Corrêa, Stephany; Binato, Renata; Du Rocher, Bárbara; Castelo-Branco, Morgana TL; Pizzatti, Luciana; Abdelhay, Eliana

    2012-01-01

    The advanced phases of chronic myeloid leukemia (CML) are known to be more resistant to therapy. This resistance has been associated with the overexpression of ABCB1, which gives rise to the multidrug resistance (MDR) phenomenon. MDR is characterized by resistance to nonrelated drugs, and P-glycoprotein (encoded by ABCB1) has been implicated as the major cause of its emergence. Wnt signaling has been demonstrated to be important in several aspects of CML. Recently, Wnt signaling was linked to ABCB1 regulation through its canonical pathway, which is mediated by β-catenin, in other types of cancer. In this study, we investigated the involvement of the Wnt/β-catenin pathway in the regulation of ABCB1 transcription in CML, as the basal promoter of ABCB1 has several β-catenin binding sites. β-catenin is the mediator of canonical Wnt signaling, which is important for CML progression. In this work we used the K562 cell line and its derived MDR-resistant cell line Lucena (K562/VCR) as CML study models. Real time PCR (RT-qPCR), electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), flow cytometry (FACS), western blot, immunofluorescence, RNA knockdown (siRNA) and Luciferase reporter approaches were used. β-catenin was present in the protein complex on the basal promoter of ABCB1 in both cell lines in vitro, but its binding was more pronounced in the resistant cell line in vivo. Lucena cells also exhibited higher β-catenin levels compared to its parental cell line. Wnt1 and β-catenin depletion and overexpression of nuclear β-catenin, together with TCF binding sites activation demonstrated that ABCB1 is positively regulated by the canonical pathway of Wnt signaling. These results suggest, for the first time, that the Wnt/β-catenin pathway regulates ABCB1 in CML

  16. Mitochondrial uncoupler exerts a synthetic lethal effect against β-catenin mutant tumor cells.

    Science.gov (United States)

    Shikata, Yuki; Kiga, Masaki; Futamura, Yushi; Aono, Harumi; Inoue, Hiroyuki; Kawada, Manabu; Osada, Hiroyuki; Imoto, Masaya

    2017-04-01

    The wingless/int-1 (Wnt) signal transduction pathway plays a central role in cell proliferation, survival, differentiation and apoptosis. When β-catenin: a component of the Wnt pathway, is mutated into an active form, cell growth signaling is hyperactive and drives oncogenesis. As β-catenin is mutated in a wide variety of tumors, including up to 10% of all sporadic colon carcinomas and 20% of hepatocellular carcinomas, it has been considered a promising target for therapeutic interventions. Therefore, we screened an in-house natural product library for compounds that exhibited synthetic lethality towards β-catenin mutations and isolated nonactin, an antibiotic mitochondrial uncoupler, as a hit compound. Nonactin, as well as other mitochondrial uncouplers, induced apoptosis selectively in β-catenin mutated tumor cells. Significant tumor regression was observed in the β-catenin mutant HCT 116 xenograft model, but not in the β-catenin wild type A375 xenograft model, in response to daily administration of nonactin in vivo. Furthermore, we found that expression of an active mutant form of β-catenin induced a decrease in the glycolysis rate. Taken together, our results demonstrate that tumor cells with mutated β-catenin depend on mitochondrial oxidative phosphorylation for survival. Therefore, they undergo apoptosis in response to mitochondrial dysfunction following the addition of mitochondrial uncouplers, such as nonactin. These results suggest that targeting mitochondria is a potential chemotherapeutic strategy for tumor cells that harbor β-catenin mutations. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  17. Hematopoietic stem cell development requires transient Wnt/β-catenin activity

    DEFF Research Database (Denmark)

    Ruiz-Herguido, Cristina; Guiu, Jordi; D'Altri, Teresa

    2012-01-01

    in the aorta-gonad-mesonephros (AGM) region. We show here that β-catenin is nuclear and active in few endothelial nonhematopoietic cells closely associated with the emerging hematopoietic clusters of the embryonic aorta during mouse development. Importantly, Wnt/β-catenin activity is transiently required...... of mutant cells toward the hematopoietic lineage; however, these mutant cells still contribute to the adult endothelium. Together, those findings indicate that Wnt/β-catenin activity is needed for the emergence but not the maintenance of HSCs in mouse embryos....

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

    Science.gov (United States)

    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.

  19. 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.

  20. The β-catenin E3 ubiquitin ligase SIAH-1 is regulated by CSN5/JAB1 in CRC cells.

    Science.gov (United States)

    Jumpertz, Sandra; Hennes, Thomas; Asare, Yaw; Vervoorts, Jörg; Bernhagen, Jürgen; Schütz, Anke K

    2014-09-01

    COP9 signalosome subunit 5 (CSN5) plays a decisive role in cellular processes such as cell cycle regulation and apoptosis via promoting protein degradation, gene transcription, and nuclear export. CSN5 regulates cullin-RING-E3 ligase (CRL) activity through its deNEDDylase function. It is overexpressed in several tumor entities, but its role in colorectal cancer (CRC) is poorly understood. Wnt/β-catenin signaling is aberrant in most CRC cells, resulting in increased levels of oncogenic β-catenin and thus tumor progression. Under physiological conditions, β-catenin levels are tightly regulated by continuous proteasomal degradation. We recently showed that knockdown of CSN5 in model and CRC cells results in decreased (phospho)-β-catenin levels. Reduced β-catenin levels were associated with an attenuated proliferation rate of different CRC cell types after CSN5 knockdown. The canonical Wnt pathway involves degradation of β-catenin by a β-TrCP1-containing E3 ligase, but is mostly non-functional in CRC cells. We thus hypothesized that alternative β-catenin degradation mediated by SIAH-1 (seven in absentia homolog-1), is responsible for the effect of CSN5 on β-catenin signaling in CRC cells. We found that SIAH-1 plays an essential role in β-catenin degradation in HCT116 CRC cells and that CSN5 affects β-catenin target gene expression in these cells. Of note, CSN5 affected SIAH-1 mRNA and SIAH-1 protein levels. Moreover, β-catenin and SIAH-1 form protein complexes with CSN5 in HCT116 cells. Lastly, we demonstrate that CSN5 promotes SIAH-1 degradation in HCT116 and SW480 cells and that this is associated with its deNEDDylase activity. In conclusion, we have identified a CSN5/β-catenin/SIAH-1 interaction network that might control β-catenin degradation in CRC cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Wnt some lose some: transcriptional governance of stem cells by Wnt/β-catenin signaling

    Science.gov (United States)

    Lien, Wen-Hui; Fuchs, Elaine

    2014-01-01

    In mammals, Wnt/β-catenin signaling features prominently in stem cells and cancers, but how and for what purposes have been matters of much debate. In this review, we summarize our current knowledge of Wnt/β-catenin signaling and its downstream transcriptional regulators in normal and malignant stem cells. We centered this review largely on three types of stem cells—embryonic stem cells, hair follicle stem cells, and intestinal epithelial stem cells—in which the roles of Wnt/β-catenin have been extensively studied. Using these models, we unravel how many controversial issues surrounding Wnt signaling have been resolved by dissecting the diversity of its downstream circuitry and effectors, often leading to opposite outcomes of Wnt/β-catenin-mediated regulation and differences rooted in stage- and context-dependent effects. PMID:25030692

  2. Parkin protects dopaminergic neurons from excessive Wnt/β-catenin signaling

    International Nuclear Information System (INIS)

    Rawal, Nina; Corti, Olga; Sacchetti, Paola; Ardilla-Osorio, Hector; Sehat, Bita; Brice, Alexis; Arenas, Ernest

    2009-01-01

    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 β-catenin protein levels in vivo. Stabilization of β-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 β-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 β-catenin-induced cell death.

  3. 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.

  4. 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.

  5. 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.

  6. Data on chemical activation of Wnt/β-catenin during axolotl limb regeneration

    Directory of Open Access Journals (Sweden)

    Sabina Wischin

    2017-04-01

    Full Text Available Limb amputation in axolotls was performed to obtain data demonstrating that a chemical agonist of Wnt (int-related protein/β-catenin signalling can have a role in axolotl limb regeneration (Wischin et al., 2017 [1]. The data revealed that active β-catenin protein was present during limb regeneration in some Leydig cells in the epithelium; after the chemical treatment, it was observed in more Leydig cells. In addition, the chemical agonist of Wnt generated distinct limb malformation.

  7. β-Catenin signaling regulates temporally discrete phases of anterior taste bud development.

    Science.gov (United States)

    Thirumangalathu, Shoba; Barlow, Linda A

    2015-12-15

    The sense of taste is mediated by multicellular taste buds located within taste papillae on the tongue. In mice, individual taste buds reside in fungiform papillae, which develop at mid-gestation as epithelial placodes in the anterior tongue. Taste placodes comprise taste bud precursor cells, which express the secreted factor sonic hedgehog (Shh) and give rise to taste bud cells that differentiate around birth. We showed previously that epithelial activation of β-catenin is the primary inductive signal for taste placode formation, followed by taste papilla morphogenesis and taste bud differentiation, but the degree to which these later elements were direct or indirect consequences of β-catenin signaling was not explored. Here, we define discrete spatiotemporal functions of β-catenin in fungiform taste bud development. Specifically, we show that early epithelial activation of β-catenin, before taste placodes form, diverts lingual epithelial cells from a taste bud fate. By contrast, β-catenin activation a day later within Shh(+) placodes, expands taste bud precursors directly, but enlarges papillae indirectly. Further, placodal activation of β-catenin drives precocious differentiation of Type I glial-like taste cells, but not other taste cell types. Later activation of β-catenin within Shh(+) precursors during papilla morphogenesis also expands taste bud precursors and accelerates Type I cell differentiation, but papilla size is no longer enhanced. Finally, although Shh regulates taste placode patterning, we find that it is dispensable for the accelerated Type I cell differentiation induced by β-catenin. © 2015. Published by The Company of Biologists Ltd.

  8. Renal Tubule Repair: Is Wnt/β-Catenin a Friend or Foe?

    Science.gov (United States)

    Gewin, Leslie S

    2018-01-24

    Wnt/β-catenin signaling is extremely important for proper kidney development. This pathway is also upregulated in injured renal tubular epithelia, both in acute kidney injury and chronic kidney disease. The renal tubular epithelium is an important target of kidney injury, and its response (repair versus persistent injury) is critical for determining whether tubulointerstitial fibrosis, the hallmark of chronic kidney disease, develops. This review discusses how Wnt/β-catenin signaling in the injured tubular epithelia promotes either repair or fibrosis after kidney injury. There is data suggesting that epithelial Wnt/β-catenin signaling is beneficial in acute kidney injury and important in tubular progenitors responsible for epithelial repair. The role of Wnt/β-catenin signaling in chronically injured epithelia is less clear. There is convincing data that Wnt/β-catenin signaling in interstitial fibroblasts and pericytes contributes to the extracellular matrix accumulation that defines fibrosis. However, some recent studies question whether Wnt/β-catenin signaling in chronically injured epithelia actually promotes fibrosis or repair.

  9. Epigenetic Activation of Wnt/β-Catenin Signaling in NAFLD-Associated Hepatocarcinogenesis

    Directory of Open Access Journals (Sweden)

    Yuan Tian

    2016-08-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD, characterized by fat accumulation in liver, is closely associated with central obesity, over-nutrition and other features of metabolic syndrome, which elevate the risk of developing hepatocellular carcinoma (HCC. The Wnt/β-catenin signaling pathway plays a significant role in the physiology and pathology of liver. Up to half of HCC patients have activation of Wnt/β-catenin signaling. However, the mutation frequencies of CTNNB1 (encoding β-catenin protein or other antagonists targeting Wnt/β-catenin signaling are low in HCC patients, suggesting that genetic mutations are not the major factor driving abnormal β-catenin activities in HCC. Emerging evidence has demonstrated that obesity-induced metabolic pathways can deregulate chromatin modifiers such as histone deacetylase 8 to trigger undesired global epigenetic changes, thereby modifying gene expression program which contributes to oncogenic signaling. This review focuses on the aberrant epigenetic activation of Wnt/β-catenin in the development of NAFLD-associated HCC. A deeper understanding of the molecular mechanisms underlying such deregulation may shed light on the identification of novel druggable epigenetic targets for the prevention and/or treatment of HCC in obese and diabetic patients.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Shigella dysenteriae infection activates proinflammatory response through β-catenin/NF-κB signaling pathway.

    Directory of Open Access Journals (Sweden)

    Ashidha Gopal

    Full Text Available Shigella dysenteriae (S.dysenteriae the causative agent of bacillary dysentery invades the human colonic epithelium resulting in severe intestinal inflammatory response and epithelial destruction. However, the mechanism by which S.dysenteriae infection regulates proinflammatory cytokines during intestinal inflammation is still obscure. In this study, we evaluated whether the interaction of β-catenin and NF-κB regulates proinflammatory cytokines TNF-α and IL-8 by modulating GSK-3β activity during S.dysenteriae infection in rat ileal loop model. Here we demonstrated that S.dysenteriae infection stimulate β-catenin degradation which in turn decreased the association between NF-κB and β-catenin. Also, we showed that S.dysenteriae infection increased GSK-3β kinase activity which in turn phosphorylates β-catenin for its degradation by ubiquitination and upregulates IL-8 through NF-κB activation thereby leading to inflammation. Thus these findings revealed the role of β-catenin/ NF-κB and GSK-3β in modulating the inflammatory response during bacterial infection and also showed that β-catenin acts as a critical regulator of inflammation.

  12. 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

  13. Comparative immunohistochemical expression of β-catenin, EGFR, ErbB2, and p63 in adamantinomatous and papillary craniopharyngiomas

    Directory of Open Access Journals (Sweden)

    Ghada E. Esheba

    2015-09-01

    Conclusion: Nuclear accumulation of β-catenin is a diagnostic hallmark of the ACP and is very helpful in the differential diagnosis between both ACP and PCP in the setting of small biopsies. Moreover, the restricted nuclear β-catenin accumulation in the cohesive cell clusters within the whorl-like areas supports that aberrant β-catenin expression may play a role in the morphogenesis of ACP.

  14. Interactions Between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma on Neuroinflammation, Demyelination, and Remyelination in Multiple Sclerosis.

    Science.gov (United States)

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

    2018-05-01

    Multiple sclerosis (MS) is marked by neuroinflammation and demyelination with loss of oligodendrocytes in the central nervous system. The immune response is regulated by WNT/beta-catenin pathway in MS. Activated NF-kappaB, a major effector of neuroinflammation, and upregulated canonical WNT/beta-catenin pathway positively regulate each other. Demyelinating events present an upregulation of WNT/beta-catenin pathway, whereas proper myelinating phases show a downregulation of WNT/beta-catenin pathway essential for the promotion of oligodendrocytes precursors cells proliferation and differentiation. The activation of WNT/beta-catenin pathway results in differentiation failure and impairment in remyelination. However, PI3K/Akt pathway and TCF7L2, two downstream targets of WNT/beta-catenin pathway, are upregulated and promote proper remyelination. The interactions of these signaling pathways remain unclear. PPAR gamma activation can inhibit NF-kappaB, and can also downregulate the WNT/beta-catenin pathway. PPAR gamma and canonical WNT/beta-catenin pathway act in an opposite manner. PPAR gamma agonists appear as a promising treatment for the inhibition of demyelination and the promotion of proper remyelination through the control of both NF-kappaB activity and canonical WNT/beta-catenin pathway.

  15. 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.

  16. PROX1 and β-catenin are prognostic markers in pancreatic ductal adenocarcinoma

    International Nuclear Information System (INIS)

    Saukkonen, Kapo; Hagström, Jaana; Mustonen, Harri; Juuti, Anne; Nordling, Stig; Kallio, Pauliina; Alitalo, Kari; Seppänen, Hanna; Haglund, Caj

    2016-01-01

    The Wnt/β-catenin pathway has a key role in regulating cellular processes and its aberrant signaling can lead to cancer development. The role of β-catenin expression in pancreatic ductal adenocarcinoma is somewhat controversial. Transcription factor PROX1 is a target of Wnt/β-catenin signaling and it is involved in carcinogenesis through alterations in its expression. The actions can be either oncogenic or tumor suppressive depending on the tissue. The aim of this study was to investigate PROX1 and β-catenin expression in pancreatic ductal adenocarcinoma (PDAC). Expression of PROX1 and β-catenin were evaluated in 156 patients by immunohistochemistry of tissue microarrays. Associations between tumor marker expression and clinicopathological parameters were assessed by the Fischer’s exact-test or the linear-by-linear association test. The Kaplan-Meier method and log-rank test were used for survival analysis. Uni- and multivariate survival analyses were carried out by the Cox regression proportional hazard model. High PROX1 expression was seen in 74 (48 %) tumors, and high β-catenin expression in 100 (65 %). High β-catenin expression was associated with lower tumor grade (p = 0.025). High PROX1 and β-catenin expression associated significantly with lower risk of death from PDAC in multivariate analysis (HR = 0.63; 95 % CI 0.42–0.95, p = 0.026; and HR = 0.54; 95 % CI 0.35–0.82, p = 0.004; respectively). The combined high expression of PROX1 and β-catenin also predicted lower risk of death from PDAC (HR = 0.46; 95 % CI 0.28–0.76, p = 0.002). In conclusion, high PROX1 and β-catenin expression were independent factors for better prognosis in pancreatic ductal adenocarcinoma. The online version of this article (doi:10.1186/s12885-016-2497-5) contains supplementary material, which is available to authorized users

  17. 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.

  18. The function of BCL9 in Wnt/β-catenin signaling and colorectal cancer cells

    International Nuclear Information System (INIS)

    Roche, Marc de la; Worm, Jesper; Bienz, Mariann

    2008-01-01

    Most cases of colorectal cancer are initiated by hyperactivation of the Wnt/β-catenin pathway due to mutations in the APC tumour suppressor, or in β-catenin itself. A recently discovered component of this pathway is Legless, which is essential for Wnt-induced transcription during Drosophila development. Limited functional information is available for its two mammalian relatives, BCL9 and B9L/BCL9-2: like Legless, these proteins bind to β-catenin, and RNAi-mediated depletion of B9L/BCL9-2 has revealed that this protein is required for efficient β-catenin-mediated transcription in mammalian cell lines. No loss-of-function data are available for BCL9. We have used overexpression of dominant-negative forms of BCL9, and RNAi-mediated depletion, to study its function in human cell lines with elevated Wnt pathway activity, including colorectal cancer cells. We found that BCL9 is required for efficient β-catenin-mediated transcription in Wnt-stimulated HEK 293 cells, and in the SW480 colorectal cancer cell line whose Wnt pathway is active due to APC mutation. Dominant-negative mutants of BCL9 indicated that its function depends not only on its β-catenin ligand, but also on an unknown ligand of its C-terminus. Finally, we show that BCL9 and B9L are both Wnt-inducible genes, hyperexpressed in colorectal cancer cell lines, indicating that they are part of a positive feedback loop. BCL9 is required for efficient β-catenin-mediated transcription in human cell lines whose Wnt pathway is active, including colorectal cancer cells, indicating its potential as a drug target in colorectal cancer

  19. Wnt/β-catenin Signaling in Osteoarthritis and in Other Forms of Arthritis.

    Science.gov (United States)

    Zhou, Yachuan; Wang, Tingyu; Hamilton, John L; Chen, Di

    2017-09-01

    Arthritis defines a large group of diseases primarily affecting the joint. It is the leading cause of pain and disability in adults. Osteoarthritis (OA) affecting the knee or hip is the most common form among over 100 types of arthritis. Other types of arthritis include erosive hand OA, temporomandibular joint (TMJ) OA, facet joint OA, diffuse idiopathic skeletal hyperostosis (DISH), and spondyloarthritis (SpA). However, the specific molecular signals involved in the development and progression of OA and related forms of arthritis remain largely unknown. The canonical wingless/integrated (Wnt)/β-catenin signaling pathway could play a unique role in the pathogenesis of arthritis. In this review article, we will focus on the molecular mechanisms of Wnt/β-catenin signaling in the pathogenesis of OA and other types of arthritis. Emerging evidence demonstrates that Wnts and Wnt-related molecules are involved in arthritis development and progression in human genetic studies and in vitro studies. Also, mouse models have been generated to determine the role of Wnt/β-catenin signaling in the pathogenesis of arthritis. Wnt/β-catenin signaling represents a unique signaling pathway regulating arthritis development and progression, and the molecules in this particular pathway may serve as targets for the therapeutic intervention of arthritis. Mediators and downstream effectors of Wnt/β-catenin signaling are increased in OA as well other forms of arthritis, including DISH and SpA. Through extensive investigations, including pre-clinical studies in transgenic mice and translational and human studies, the Wnt/β-catenin signaling pathway has been proven to play roles in bone and joint pathology by directly affecting bone, cartilage, and synovial tissue; further, these pathologies can be reduced through targeting this pathway. Continued investigation into the distinct molecular signaling of the Wnt/β-catenin pathway will provide additional insights toward the therapeutic

  20. 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.

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

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    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.

  2. Subchronic treatment with fluoxetine and ketanserin increases hippocampal brain-derived neurotrophic factor, β-catenin and antidepressant-like effects.

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    Pilar-Cuéllar, F; Vidal, R; Pazos, A

    2012-02-01

    5-HT(2A) receptor antagonists improve antidepressant responses when added to 5-HT-selective reuptake inhibitors (SSRIs) or tricyclic antidepressants. Here, we have studied the involvement of neuroplasticity pathways and/or the 5-hydroxytryptaminergic system in the antidepressant-like effect of this combined treatment, given subchronically. Expression of brain-derived neurotrophic factor (BDNF) and its receptor (TrkB), 5-bromo-2'-deoxyuridine (BrdU) incorporation, and β-catenin protein expression in different cellular fractions, as well as 5-HT(1A) receptor function were measured in the hippocampus of rats treated with fluoxetine, ketanserin and fluoxetine + ketanserin for 7 days, followed by a forced swimming test (FST) to analyse antidepressant efficacy. mRNA for BDNF was increased in the CA3 field and dentate gyrus of the hippocampus by combined treatment with fluoxetine + ketanserin. Expression of β-catenin was increased in total hippocampal homogenate and in the membrane fraction, but unchanged in the nuclear fraction after combined treatment with fluoxetine + ketanserin. These effects were paralleled by a decreased immobility time in the FST. There were no changes in BrdU incorporation, TrkB expression and 5-HT(1A) receptor function in any of the groups studied. The antidepressant-like effect induced by subchronic co-treatment with a SSRI and a 5-HT(2A) receptor antagonist may mainly be because of modifications in hippocampal neuroplasticity (BDNF and membrane-associated β-catenin), without a significant role for other mechanisms involved in chronic antidepressant response, such as hippocampal neuroproliferation or 5-HT(1A) receptor desensitization in the dorsal raphe nucleus. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  3. Elevated Levels of Dickkopf-1 Are Associated with β-Catenin Accumulation and Poor Prognosis in Patients with Chondrosarcoma

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    Chen, Changbao; Zhou, Hua; Zhang, Xiaolin; Ma, Xinlong; Liu, Zhongjun; Liu, Xiaoguang

    2014-01-01

    Background Dickkopf-1 (DKK1) is an antagonist of Wnt/β-catenin signaling implicated in tumorigenesis. However, the biological role of DKK1 and β-catenin involved in chondrosarcoma has not been sufficiently investigated. This study was designed to investigate the expression profiles of DKK1 and β-catenin, and to clarify their clinical values in chondrosarcoma. Methods The mRNA and protein levels of DKK1 and β-catenin in fresh chondrosarcoma and the corresponding non-tumor tissues were analyzed by Real-time PCR and Western blot, respectively. The protein expression patterns of DKK1 and β-catenin were investigated by immunohistochemistry. The associations among DKK1 level, β-catenin accumulation, clinicopathological factors and the overall survival were separately evaluated. Results Both DKK1 and β-catenin levels were remarkably elevated in chondrosarcoma compared with the corresponding non-tumor tissues. High DKK1 level and positive β-catenin accumulation in chondrosarcoma specimens were 58.7% and 53.9%, respectively. Elevated DKK1 level significantly correlated with positive β-catenin accumulation, and they were remarkably associated with histological grade and Musculoskeletal Tumor Society stage. Furthermore, DKK1 level and β-catenin accumulation had significant impacts on the prognosis of chondrosarcoma patients. Multivariate analysis revealed that DKK1 level was an independent prognostic factor for overall survival. Conclusions Elevated DKK1 levels associated with β-catenin accumulation play a crucial role in chondrosarcoma. DKK1 can serve as a novel predictor of poor prognosis in patients with chondrosarcoma. PMID:25144498

  4. 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

  5. The canonical way to make a heart: β-catenin and plakoglobin in heart development and remodeling.

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    Piven, Oksana O; Winata, Cecilia L

    2017-12-01

    The main mediator of the canonical Wnt pathway, β-catenin, is a major effector of embryonic development, postnatal tissue homeostasis, and adult tissue regeneration. The requirement for β-catenin in cardiogenesis and embryogenesis has been well established. However, many questions regarding the molecular mechanisms by which β-catenin and canonical Wnt signaling regulate these developmental processes remain unanswered. An interesting question that emerged from our studies concerns how β-catenin signaling is modulated through interaction with other factors. Recent experimental data implicate new players in canonical Wnt signaling, particularly those which modulate β-catenin function in many its biological processes, including cardiogenesis. One of the interesting candidates is plakoglobin, a little-studied member of the catenin family which shares several mechanistic and functional features with its close relative, β-catenin. Here we have focused on the function of β-catenin in cardiogenesis. We also summarize findings on plakoglobin signaling function and discuss possible interplays between β-catenin and plakoglobin in the regulation of embryonic heart development. Impact statement Heart development, function, and remodeling are complex processes orchestrated by multiple signaling networks. This review examines our current knowledge of the role of canonical Wnt signaling in cardiogenesis and heart remodeling, focusing primarily on the mechanistic action of its effector β-catenin. We summarize the generally accepted understanding of the field based on experimental in vitro and in vivo data, and address unresolved questions in the field, specifically relating to the role of canonical Wnt signaling in heart maturation and regeneration. What are the modulators of canonical Wnt, and particularly what are the potential roles of plakoglobin, a close relative of β-catenin, in regulating Wnt signaling?Answers to these questions will enhance our understanding of the

  6. MGAT1 is a novel transcriptional target of Wnt/β-catenin signaling pathway.

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    Akiva, Izzet; Birgül Iyison, Necla

    2018-01-08

    The Wnt/β-catenin signaling pathway is an evolutionary conserved pathway, which has important functions in vertebrate early development, axis formation, cellular proliferation and morphogenesis. Additionally, Wnt/β-catenin signaling pathway is one of the most important intracellular pathways that controls cancer progression. To date most of the identified targets of this pathway are shown to harbor tumorigenic properties. We previously showed that Mannosyl glycoprotein acetylglucosaminyl-transferase (MGAT1) enzyme is among the Wnt/β-catenin signaling putative target genes in hepatocellular carcinoma cell lines (Huh7). MGAT1 protein levels were determined by Western Blotting from Huh7 cell lines in which Wnt/β-catenin pathway was activated by means of different approaches such as LiCl treatment and mutant β-catenin overexpression. Luciferase reporter assay was used to analyze the promoter activity of MGAT1. The mRNA levels of MGAT1 were determined by quantitative real-time PCR from Huh7 cells that were treated with either Wnt agonist or GSK-3β inhibitor. Wound healing and XTT cell proliferation assays were performed in order to determine the proliferation and migration capacities of MGAT1 overexpressing stable Huh7 cells. Finally, xenograft experiments were carried out to measure the tumor formation capacities in vivo. In this study we showed that the activation of Wnt/β-catenin pathway culminates in the upregulation of MGAT1 enzyme both at transcriptional and post-transcriptional levels. We also showed that overexpression of the β-catenin gene (CTNNB1) increased the promoter activity of MGAT1. We applied a set of complementary approaches to elucidate the functional importance of MGAT1 as a vital target of Wnt/β-catenin signaling in Huh7 cells. Our analyses related to cell proliferation and migration assays showed that in comparison to the control cells, MGAT1 expressing Huh7 cells have greater proliferative and invasive capabilities. Furthermore, the

  7. β-Catenin acts in a position-independent regeneration response in the simple eumetazoan Hydra.

    Science.gov (United States)

    Gufler, S; Artes, B; Bielen, H; Krainer, I; Eder, M-K; Falschlunger, J; Bollmann, A; Ostermann, T; Valovka, T; Hartl, M; Bister, K; Technau, U; Hobmayer, B

    2018-01-15

    Wnt/β-Catenin signaling plays crucial roles in regenerative processes in eumetazoans. It also acts in regeneration and axial patterning in the simple freshwater polyp Hydra, whose morphallactic regenerative capacity is unparalleled in the animal kingdom. Previous studies have identified β-catenin as an early response gene activated within the first 30min in Hydra head regeneration. Here, we have studied the role of β-Catenin in more detail. First, we show that nuclear β-Catenin signaling is required for head and foot regeneration. Loss of nuclear β-Catenin function blocks head and foot regeneration. Transgenic Hydra tissue, in which β-Catenin is over-expressed, regenerates more heads and feet. In addition, we have identified a set of putative β-Catenin target genes by transcriptional profiling, and these genes exhibit distinct expression patterns in the hypostome, in the tentacles, or in an apical gradient in the body column. All of them are transcriptionally up-regulated in the tips of early head and foot regenerates. In foot regenerates, this is a transient response, and expression starts to disappear after 12-36h. ChIP experiments using an anti-HydraTcf antibody show Tcf binding at promoters of these targets. We propose that gene regulatory β-Catenin activity in the pre-patterning phase is generally required as an early regeneration response. When regenerates are blocked with iCRT14, initial local transcriptional activation of β-catenin and the target genes occurs, and all these genes remain upregulated at the site of both head and foot regeneration for the following 2-3 days. This indicates that the initial regulatory network is followed by position-specific programs that inactivate fractions of this network in order to proceed to differentiation of head or foot structures. brachyury1 (hybra1) has previously been described as early response gene in head and foot regeneration. The HyBra1 protein, however, appears in head regenerating tips not earlier

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

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    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

  9. Real-time TIRF observation of vinculin recruitment to stretched α-catenin by AFM.

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    Maki, Koichiro; Han, Sung-Woong; Hirano, Yoshinori; Yonemura, Shigenobu; Hakoshima, Toshio; Adachi, Taiji

    2018-01-25

    Adherens junctions (AJs) adaptively change their intensities in response to intercellular tension; therefore, they integrate tension generated by individual cells to drive multicellular dynamics, such as morphogenetic change in embryos. Under intercellular tension, α-catenin, which is a component protein of AJs, acts as a mechano-chemical transducer to recruit vinculin to promote actin remodeling. Although in vivo and in vitro studies have suggested that α-catenin-mediated mechanotransduction is a dynamic molecular process, which involves a conformational change of α-catenin under tension to expose a cryptic vinculin binding site, there are no suitable experimental methods to directly explore the process. Therefore, in this study, we developed a novel system by combining atomic force microscopy (AFM) and total internal reflection fluorescence (TIRF). In this system, α-catenin molecules (residues 276-634; the mechano-sensitive M 1 -M 3 domain), modified on coverslips, were stretched by AFM and their recruitment of Alexa-labeled full-length vinculin molecules, dissolved in solution, were observed simultaneously, in real time, using TIRF. We applied a physiologically possible range of tensions and extensions to α-catenin and directly observed its vinculin recruitment. Our new system could be used in the fields of mechanobiology and biophysics to explore functions of proteins under tension by coupling biomechanical and biochemical information.

  10. Prognostic Value of E-Cadherin and β-Catenin in Triple-Negative Breast Cancer.

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    Shen, Tiansheng; Zhang, Kui; Siegal, Gene P; Wei, Shi

    2016-11-01

    To analyze the expression of E-cadherin and β-catenin in triple-negative breast cancer (TNBC) to assess their prognostic significance. The expression of E-cadherin and β-catenin was examined semiquantitatively and correlated with other pathologic factors and survival outcomes. Of 72 consecutive TNBCs, 56% showed reduced membranous expression of E-cadherin or β-catenin, with a strong correlation to each other. Of the clinicopathologic factors analyzed, tumor size and nodal status were significantly associated with overall survival and disease-specific survival, while the latter remained an independent factor by multivariate analysis. Reduced E-cadherin and β-catenin were both significantly associated with a poor overall survival and disease-specific survival by univariate and multivariate analyses. E-cadherin and β-catenin expression provides discriminative prognostic power independent of conventional pathologic factors, thus further reinforcing the important role of cell adhesion molecules in the process of tumor metastasis, especially in TNBC. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  11. β-Catenin-Dependent Wnt Signaling in C. elegans: Teaching an Old Dog a New Trick

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    Jackson, Belinda M.; Eisenmann, David M.

    2012-01-01

    Wnt signaling is an evolutionarily ancient pathway used to regulate many events during metazoan development. Genetic results from Caenorhabditis elegans more than a dozen years ago suggested that Wnt signaling in this nematode worm might be different than in vertebrates and Drosophila: the worm had a small number of Wnts, too many β-catenins, and some Wnt pathway components functioned in an opposite manner than in other species. Work over the ensuing years has clarified that C. elegans does possess a canonical Wnt/β-catenin signaling pathway similar to that in other metazoans, but that the majority of Wnt signaling in this species may proceed via a variant Wnt/β-catenin signaling pathway that uses some new components (mitogen-activated protein kinase signaling enzymes), and in which some conserved pathway components (β-catenin, T-cell factor [TCF]) are used in new and interesting ways. This review summarizes our current understanding of the canonical and novel TCF/β-catenin-dependent signaling pathways in C. elegans. PMID:22745286

  12. β-catenin as a prognostic factor for prostate cancer (PCa)

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    Nowicki, Andrzej; Duda-Szymańska, Joanna

    2012-01-01

    Introduction The prostate cancer is difficult to predict, and treatment failure is associated with local infiltration, as well as distant metastases. Adhesion and migration abilities to of cancer cells play a major role in formation of metastasis. The participation of β-catenin in pathogene-sis of many types of cancer and benign processes has been an important discovery of recent years. Material and methods The studied material was obtained by transrectal, sextant core biopsy from 102 patients hospitalized in Department of Urology, Regional Hospital in Kalisz (2001-2004). The aim of our study was to determine the predictive value of β-catenin immunoexpression in prostate cancer, to analyze the prognostic aspect of some histopathological features and finally to assess the relationship between β-catenin immunoreactivity and the microscopic image of the tumor. Relationships between the investigated variables were analyzed using the Chi2 test of compatibility. We used the Kaplan-Meier curves to assess survival differences between groups of patients. Finally we established which of the studied factors significantly affect the patient outcome, using the method of Cox proportional hazard regression. Results In prostate cancer in comparison with the normal epithelium, both the location and the strength of β-catenin immunoexpression are impaired. Conclusions Our results indicate that the presence of disorders in β-catenin immunoexpression in prostate cancer cells indicates a high risk of death due to tumor progression and makes it imperative for immediate treatment procedures. PMID:24578946

  13. The Wnt/β-catenin pathway is deregulated in cemento-ossifying fibromas.

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    Pereira, Thaís Dos Santos Fontes; Diniz, Marina Gonçalves; França, Josiane Alves; Moreira, Rennan Garcias; Menezes, Grazielle Helena Ferreira de; Sousa, Sílvia Ferreira de; Castro, Wagner Henriques de; Gomes, Carolina Cavaliéri; Gomez, Ricardo Santiago

    2018-02-01

    The molecular pathogenesis of cemento ossifying fibroma (COF) is unclear. The purpose of this study was to investigate mutations in 50 oncogenes and tumor suppressor genes, including APC and CTNNB1, in which mutations in COF have been previously reported. In addition, we assessed the transcriptional levels of the Wnt/β-catenin pathway genes in COF. We used a quantitative polymerase chain reaction array to evaluate the transcriptional levels of 44 Wnt/β-catenin pathway genes in 6 COF samples, in comparison with 6 samples of healthy jaws. By using next-generation sequencing (NGS) in 7 COF samples, we investigated approximately 2800 mutations in 50 genes. The expression assay revealed 12 differentially expressed Wnt/β-catenin pathway genes in COF, including the upregulation of CTNNB1, TCF7, NKD1, and WNT5 A, and downregulation of CTNNBIP1, FRZB, FZD6, RHOU, SFRP4, WNT10 A, WNT3 A, and WNT4, suggesting activation of the Wnt/β-catenin signaling pathway. NGS revealed 5 single nucleotide variants: TP53 (rs1042522), PIK3 CA (rs2230461), MET (rs33917957), KIT (rs3822214), and APC (rs33974176), but none of them was pathogenic. Although NGS detected no oncogenic mutation, deregulation of key Wnt/β-catenin signaling pathway genes appears to be relevant to the molecular pathogenesis of COF. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. 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.

  15. 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.

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

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    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

  17. Wnt/beta-catenin signaling interacts differentially with Ihh signaling in controlling endochondral bone and synovial joint formation.

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    Mak, Kingston Kinglun; Chen, Miao-Hsueh; Day, Timothy F; Chuang, Pao-Tien; Yang, Yingzi

    2006-09-01

    Both the Wnt/beta-catenin and Ihh signaling pathways play essential roles in crucial aspects of endochondral ossification: osteoblast differentiation, chondrocyte proliferation and hypertrophy. To understand the genetic interaction between these two signaling pathways, we have inactivated the beta-catenin gene and upregulated Ihh signaling simultaneously in the same cells during endochondral skeletal development using beta-catenin and patched 1 floxed alleles. We uncovered previously unexpected roles of Ihh signaling in synovial joint formation and the essential function of Wnt/beta-catenin signaling in regulating chondrocyte survival. More importantly, we found that Wnt and Ihh signaling interact with each other in distinct ways to control osteoblast differentiation, chondrocyte proliferation, hypertrophy, survival and synovial joint formation in the developing endochondral bone. Beta-catenin is required downstream of Ihh signaling and osterix expression for osteoblast differentiation. But in chondrocyte survival, beta-catenin is required upstream of Ihh signaling to inhibit chondrocyte apoptosis. In addition, Ihh signaling can inhibit chondrocyte hypertrophy and synovial joint formation independently of beta-catenin. However, there is a strong synergistic interaction between Wnt/beta-catenin and Ihh signaling in regulating synovial joint formation.

  18. PAI-1 modulates cell migration in a LRP1-dependent manner via β-catenin and ERK1/2

    DEFF Research Database (Denmark)

    Kozlova, Nina; Jensen, Jan Kristian; Chi, Tabughang Franklin

    2015-01-01

    was proposed to modulate the β-catenin pathway. Therefore, we used wild-type mouse embryonic fibroblasts (MEFs), and MEFs deficient of LRP1 to study PAI-1 as modulator of the β-catenin pathway. We found that PAI-1 influences MEF proliferation and motility in a LRP1-dependent manner and that β...

  19. 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.

  20. Zonation of heme synthesis enzymes in mouse liver and their regulation by β-catenin and Ha-ras.

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    Braeuning, Albert; Schwarz, Michael

    2010-11-01

    Cytochrome P450 (CYP) hemoproteins play an important role in hepatic biotransformation. Recently, β-catenin and Ha-ras signaling have been identified as players controlling transcription of various CYP genes in mouse liver. The aim of the present study was to analyze the role of β-catenin and Ha-ras in the regulation of heme synthesis. Heme synthesis-related gene expression was analyzed in normal liver, in transgenic mice expressing activated β-catenin or Ha-ras, and in hepatomas. Regulation of the aminolevulinate dehydratase promoter was studied in vitro. Elevated expression of mRNAs and proteins involved in heme biosynthesis was linked to β-catenin activation in perivenous hepatocytes, in transgenic hepatocytes, and in hepatocellular tumors. Stimulation of the aminolevulinate dehydratase promoter by β-catenin was independent of the β-catenin/T-cell-specific transcription factor dimer. By contrast, activation of Ha-ras repressed heme synthesis-related gene expression. The present data suggest that β-catenin enhances the expression of both CYPs and heme synthesis-related genes, thus coordinating the availability of CYP apoprotein and its prosthetic group heme. The reciprocal regulation of heme synthesis by β-catenin and Ha-ras-dependent signaling supports our previous hypothesis that antagonistic action of these pathways plays a major role in the control of zonal gene expression in healthy mouse liver and aberrant expression patterns in hepatocellular tumors.

  1. Three-dimensional organoid culture reveals involvement of Wnt/β-catenin pathway in proliferation of bladder cancer cells.

    Science.gov (United States)

    Yoshida, Takahiro; Sopko, Nikolai A; Kates, Max; Liu, Xiaopu; Joice, Gregory; McConkey, David J; Bivalacqua, Trinity J

    2018-02-16

    There has been increasing awareness of the importance of three-dimensional culture of cancer cells. Tumor cells growing as multicellular spheroids in three-dimensional culture, alternatively called organoids, are widely believed to more closely mimic solid tumors in situ . Previous studies concluded that the Wnt/β-catenin pathway is required for regeneration of the normal urothelium after injury and that β-catenin is upregulated in human bladder cancers, but no clear evidence has been advanced to support the idea that the Wnt/β-catenin pathway is directly involved in deregulated proliferation and the other malignant characteristics of bladder cancer cells. Here we report that the Wnt/β-catenin pathway activator, CHIR99021, promoted proliferation of established human bladder cancer cell lines when they were grown in organoid culture but not when they were grown in conventional adherent cultures. CHIR99021 activated Wnt/β-catenin pathway in bladder cancer cell lines in organoid culture. CHIR99021 also stimulated proliferation and the Wnt/b-catenin pathway in primary human bladder cancer organoids. RNAi-mediated knockdown of β-catenin blocked growth of organoids. The effects of CHIR99021 were associated with decreased expression of the urothelial terminal differentiation marker, cytokeratin 20. Our data suggest that the Wnt/β-catenin pathway is required for the proliferation of bladder cancer cells in three-dimensional organoid culture and provide a concrete example of why organoid culture is important for cancer research.

  2. Wnt/β-catenin pathway in tissue injury: roles in pathology and therapeutic opportunities for regeneration

    Science.gov (United States)

    Bastakoty, Dikshya; Young, Pampee P.

    2016-01-01

    The Wnt/β-catenin pathway is an evolutionarily conserved set of signals with critical roles in embryonic and neonatal development across species. In mammals the pathway is quiescent in many organs. It is reactivated in response to injury and is reported to play complex and contrasting roles in promoting regeneration and fibrosis. We review the current understanding of the role of the Wnt/β-catenin pathway in injury of various mammalian organs and discuss the current advances and potential of Wnt inhibitory therapeutics toward promoting tissue regeneration and reducing fibrosis.—Bastakoty, D., Young, P. P. Wnt/β-catenin pathway in tissue injury: roles in pathology and therapeutic opportunities for regeneration. PMID:27335371

  3. Activation of the canonical Wnt/β-catenin pathway enhances monocyte adhesion to endothelial cells

    International Nuclear Information System (INIS)

    Lee, Dong Kun; Nathan Grantham, R.; Trachte, Aaron L.; Mannion, John D.; Wilson, Colleen L.

    2006-01-01

    Monocyte adhesion to vascular endothelium has been reported to be one of the early processes in the development of atherosclerosis. In an attempt to develop strategies to prevent or delay atherosclerosis progression, we analyzed effects of the Wnt/β-catenin signaling pathway on monocyte adhesion to various human endothelial cells. Adhesion of fluorescein-labeled monocytes to various human endothelial cells was analyzed under a fluorescent microscope. Unlike sodium chloride, lithium chloride enhanced monocyte adhesion to endothelial cells in a dose-dependent manner. We further demonstrated that inhibitors for glycogen synthase kinase (GSK)-3β or proteosome enhanced monocyte-endothelial cell adhesion. Results of semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) indicated that activation of Wnt/β-catenin pathway did not change expression levels of mRNA for adhesion molecules. In conclusion, the canonical Wnt/β-catenin pathway enhanced monocyte-endothelial cell adhesion without changing expression levels of adhesion molecules

  4. Flavonoids and Wnt/β-Catenin Signaling: Potential Role in Colorectal Cancer Therapies

    Directory of Open Access Journals (Sweden)

    Nathália G. Amado

    2014-07-01

    Full Text Available It is now well documented that natural products have played an important role in anticancer therapy. Many studies focus on the ability of these natural compounds to modulate tumor-related signaling pathways and the relationship of these properties to an anticancer effect. According to the World Health Organization (WHO, colorectal cancer (CRC is the third most common cancer and the fourth leading cause of cancer death among men and women. Therefore, finding strategies to fight against CRC is an emergent health problem. CRC has a strong association with deregulation of Wnt/β-catenin signaling pathway. As some types of natural compounds are capable of modulating the Wnt/β-catenin signaling, one important question is whether they could counteract CRC. In this review, we discuss the role of flavonoids, a class of natural compounds, on Wnt/β-catenin regulation and its possible potential for therapeutic usage on colorectal cancer.

  5. 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

  6. Crosstalk between long non-coding RNAs and Wnt/β-catenin signalling in cancer.

    Science.gov (United States)

    Yang, Gang; Shen, Tianyi; Yi, Xiaoming; Zhang, Zhengyu; Tang, Chaopeng; Wang, Longxin; Zhou, Yulin; Zhou, Wenquan

    2018-04-01

    Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts in the human genome which perform crucial functions in diverse biological processes. The abnormal expression of some lncRNAs has been found in tumorigenesis, development and therapy resistance of cancers. They may act as oncogenes or tumour suppressors and can be used as diagnostic or prognostic markers, prompting their therapeutic potentials in cancer treatments. Studies have indicated that many lncRNAs are involved in the regulation of several signal pathways, including Wnt/β-catenin signalling pathway, which has been reported to play a significant role in regulating embryogenesis, cell proliferation and controlling tumour biology. Emerging evidences have suggested that lncRNAs can interact with several components of the Wnt/β-catenin signalling pathway to regulate the expression of Wnt target genes in cancer. Moreover, the expression of lncRNAs can also be influenced by the pathway. Nevertheless, Wnt/β-catenin signalling pathway-related lncRNAs and their interactions in cancer are not systematically analysed before. Considering these, this review emphasized the associations between lncRNAs and Wnt/β-catenin signalling pathway in cancer initiation, progression and their therapeutic influence. We also provided an overview on characteristics of lncRNAs and Wnt/β-catenin signalling pathway and discussed their functions in tumour biology. Finally, targeting lncRNAs or/and molecules associated with the Wnt/β-catenin signalling pathway may be a feasible therapeutic method in the future. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Glutamate acid decarboxylase 1 promotes metastasis of human oral cancer by β-catenin translocation and MMP7 activation

    International Nuclear Information System (INIS)

    Kimura, Ryota; Tanzawa, Hideki; Uzawa, Katsuhiro; Kasamatsu, Atsushi; Koyama, Tomoyoshi; Fukumoto, Chonji; Kouzu, Yukinao; Higo, Morihiro; Endo-Sakamoto, Yosuke; Ogawara, Katsunori; Shiiba, Masashi

    2013-01-01

    Glutamate decarboxylase 1 (GAD1), a rate-limiting enzyme in the production of γ-aminobutyric acid (GABA), is found in the GABAergic neurons of the central nervous system. Little is known about the relevance of GAD1 to oral squamous cell carcinoma (OSCC). We investigated the expression status of GAD1 and its functional mechanisms in OSCCs. We evaluated GAD1 mRNA and protein expressions in OSCC-derived cells using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunoblotting analyses. To assess the critical functions of GAD1, i.e., cellular proliferation, invasiveness, and migration, OSCC-derived cells were treated with the shRNA and specific GAD1 inhibitor, 3-mercaptopropionic acid (3-MPA). GAD1 expression in 80 patients with primary OSCCs was analyzed and compared to the clinicopathological behaviors of OSCC. qRT-PCR and immunoblotting analyses detected frequent up-regulation of GAD1 in OSCC-derived cells compared to human normal oral keratinocytes. Suppression of nuclear localization of β-catenin and MMP7 secretion was observed in GAD1 knockdown and 3-MPA-treated cells. We also found low cellular invasiveness and migratory abilities in GAD1 knockdown and 3-MPA-treated cells. In the clinical samples, GAD1 expression in the primary OSCCs was significantly (P < 0.05) higher than in normal counterparts and was correlated significantly (P < 0.05) with regional lymph node metastasis. Our data showed that up-regulation of GAD1 was a characteristic event in OSCCs and that GAD1 was correlated with cellular invasiveness and migration by regulating β-catenin translocation and MMP7 activation. GAD1 might play an important role in controlling tumoral invasiveness and metastasis in oral cancer

  10. β‑catenin nuclear translocation induced by HIF‑1α overexpression leads to the radioresistance of prostate cancer.

    Science.gov (United States)

    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.

  11. 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.

  12. 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.

  13. 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.

  14. Wnt/β-catenin Signaling in Normal and Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Kenneth C. Valkenburg

    2011-04-01

    Full Text Available The ability of Wnt ligands to initiate a signaling cascade that results in cytoplasmic stabilization of, and nuclear localization of, β-catenin underlies their ability to regulate progenitor cell differentiation. In this review, we will summarize the current knowledge of the mechanisms underlying Wnt/β-catenin signaling and how the pathway regulates normal differentiation of stem cells in the intestine, mammary gland, and prostate. We will also discuss how dysregulation of the pathway is associated with putative cancer stem cells and the potential therapeutic implications of regulating Wnt signaling.

  15. 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

  16. 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

  17. Wnt3a upregulates brain-derived insulin by increasing NeuroD1 via Wnt/β-catenin signaling in the hypothalamus.

    Science.gov (United States)

    Lee, Jaemeun; Kim, Kyungchan; Yu, Seong-Woon; Kim, Eun-Kyoung

    2016-03-08

    Insulin plays diverse roles in the brain. Although insulin produced by pancreatic β-cells that crosses the blood-brain barrier is a major source of brain insulin, recent studies suggest that insulin is also produced locally within the brain. However, the mechanisms underlying the production of brain-derived insulin (BDI) are not yet known. Here, we examined the effect of Wnt3a on BDI production in a hypothalamic cell line and hypothalamic tissue. In N39 hypothalamic cells, Wnt3a treatment significantly increased the expression of the Ins2 gene, which encodes the insulin isoform predominant in the mouse brain, by activating Wnt/β-catenin signaling. The concentration of insulin was higher in culture medium of Wnt3a-treated cells than in that of untreated cells. Interestingly, neurogenic differentiation 1 (NeuroD1), a target of Wnt/β-catenin signaling and one of transcription factors for insulin, was also induced by Wnt3a treatment in a time- and dose-dependent manner. In addition, the treatment of BIO, a GSK3 inhibitor, also increased the expression of Ins2 and NeuroD1. Knockdown of NeuroD1 by lentiviral shRNAs reduced the basal expression of Ins2 and suppressed Wnt3a-induced Ins2 expression. To confirm the Wnt3a-induced increase in Ins2 expression in vivo, Wnt3a was injected into the hypothalamus of mice. Wnt3a increased the expression of NeuroD1 and Ins2 in the hypothalamus in a manner similar to that observed in vitro. Taken together, these results suggest that BDI production is regulated by the Wnt/β-catenin/NeuroD1 pathway in the hypothalamus. Our findings will help to unravel the regulation of BDI production in the hypothalamus.

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

    Science.gov (United States)

    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.

  19. 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

  20. 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

  1. 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.

  2. The PDZ protein tax-interacting protein-1 inhibits beta-catenin transcriptional activity and growth of colorectal cancer cells.

    Science.gov (United States)

    Kanamori, Mutsumi; Sandy, Peter; Marzinotto, Stefania; Benetti, Roberta; Kai, Chikatoshi; Hayashizaki, Yoshihide; Schneider, Claudio; Suzuki, Harukazu

    2003-10-03

    Wnt signaling is essential during development while deregulation of this pathway frequently leads to the formation of various tumors including colorectal carcinomas. A key component of the pathway is beta-catenin that, in association with TCF-4, directly regulates the expression of Wnt-responsive genes. To identify novel binding partners of beta-catenin that may control its transcriptional activity, we performed a mammalian two-hybrid screen and isolated the Tax-interacting protein (TIP-1). The in vivo complex formation between beta-catenin and TIP-1 was verified by coimmunoprecipitation, and a direct physical association was revealed by glutathione S-transferase pull-down experiments in vitro. By using a panel of deletion mutants of both proteins, we demonstrate that the interaction is mediated by the PDZ (PSD-95/DLG/ZO-1 homology) domain of TIP-1 and requires primarily the last four amino acids of beta-catenin. TIP-1 overexpression resulted in a dose-dependent decrease in the transcriptional activity of beta-catenin when tested on the TOP/FOPFLASH reporter system. Conversely, siRNA-mediated knock-down of endogenous TIP-1 slightly increased endogenous beta-catenin transactivation function. Moreover, we show that overexpression of TIP-1 reduced the proliferation and anchorage-independent growth of colorectal cancer cells. These data suggest that TIP-1 may represent a novel regulatory element in the Wnt/beta-catenin signaling pathway.

  3. Ethacrynic acid exhibits selective toxicity to chronic lymphocytic leukemia cells by inhibition of the Wnt/beta-catenin pathway.

    Directory of Open Access Journals (Sweden)

    Desheng Lu

    Full Text Available BACKGROUND: Aberrant activation of Wnt/beta-catenin signaling promotes the development of several cancers. It has been demonstrated that the Wnt signaling pathway is activated in chronic lymphocytic leukemia (CLL cells, and that uncontrolled Wnt/beta-catenin signaling may contribute to the defect in apoptosis that characterizes this malignancy. Thus, the Wnt signaling pathway is an attractive candidate for developing targeted therapies for CLL. METHODOLOGY/PRINCIPAL FINDINGS: The diuretic agent ethacrynic acid (EA was identified as a Wnt inhibitor using a cell-based Wnt reporter assay. In vitro assays further confirmed the inhibitory effect of EA on Wnt/beta-catenin signaling. Cell viability assays showed that EA selectively induced cell death in primary CLL cells. Exposure of CLL cells to EA decreased the expression of Wnt/beta-catenin target genes, including LEF-1, cyclin D1 and fibronectin. Immune co-precipitation experiments demonstrated that EA could directly bind to LEF-1 protein and destabilize the LEF-1/beta-catenin complex. N-acetyl-L-cysteine (NAC, which can react with the alpha, beta-unsaturated ketone in EA, but not other anti-oxidants, prevented the drug's inhibition of Wnt/beta-catenin activation and its ability to induce apoptosis in CLL cells. CONCLUSIONS/SIGNIFICANCE: Our studies indicate that EA selectively suppresses CLL survival due to inhibition of Wnt/beta-catenin signaling. Antagonizing Wnt signaling in CLL with EA or related drugs may represent an effective treatment of this disease.

  4. 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.

  5. 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.

  6. Over-expression of β-catenin is associated with high grade of ...

    African Journals Online (AJOL)

    W. Said

    2017-04-28

    Apr 28, 2017 ... Wnt/ß-catenin signaling has been implicated in both normal prostate development ... The assessment of staining was performed with a light micro- scope at ... sion, no detectable staining in <10% of the membrane, +: weak but detectable ..... New experimental markers for early detection of high-risk prostate.

  7. 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

  8. Surrogate Wnt agonists that phenocopy canonical Wnt and β-catenin signalling

    NARCIS (Netherlands)

    Janda, Claudia Y.; Dang, Luke T.; You, Changjiang; Chang, Junlei; Lau, Wim De; Zhong, Zhendong A.; Yan, Kelley S.; Marecic, Owen; Siepe, DIrk; Li, Xingnan; Moody, James D.; Williams, Bart O.; Clevers, Hans; Piehler, Jacob; Baker, David; Kuo, Calvin J.; Garcia, K. Christopher

    2017-01-01

    Wnt proteins modulate cell proliferation and differentiation and the self-renewal of stem cells by inducing β-catenin-dependent signalling through the Wnt receptor frizzled (FZD) and the co-receptors LRP5 and LRP6 to regulate cell fate decisions and the growth and repair of several tissues. The 19

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  15. Podoplanin regulates mammary stem cell function and tumorigenesis by potentiating Wnt/β-catenin signaling.

    Science.gov (United States)

    Bresson, Laura; Faraldo, Marisa M; Di-Cicco, Amandine; Quintanilla, Miguel; Glukhova, Marina A; Deugnier, Marie-Ange

    2018-02-21

    Stem cells (SCs) drive mammary development, giving rise postnatally to an epithelial bilayer composed of luminal and basal myoepithelial cells. Dysregulation of SCs is thought to be at the origin of certain breast cancers; however, the molecular identity of SCs and the factors regulating their function remain poorly defined. We identified the transmembrane protein podoplanin (Pdpn) as a specific marker of the basal compartment, including multipotent SCs, and found Pdpn localized at the basal-luminal interface. Embryonic deletion of Pdpn targeted to basal cells diminished basal and luminal SC activity and affected the expression of several Wnt/β-catenin signaling components in basal cells. Moreover, Pdpn loss attenuated mammary tumor formation in a mouse model of β-catenin-induced breast cancer, limiting tumor-initiating cell expansion and promoting molecular features associated with mesenchymal-to-epithelial cell transition. In line with the loss-of-function data, we demonstrated that mechanistically Pdpn enhances Wnt/β-catenin signaling in mammary basal cells. Overall, this study uncovers a role for Pdpn in mammary SC function and, importantly, identifies Pdpn as a new regulator of Wnt/β-catenin signaling, a key pathway in mammary development and tumorigenesis. © 2018. Published by The Company of Biologists Ltd.

  16. 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,

  17. Localized decrease of β-catenin contributes to the differentiation of human embryonic stem cells

    International Nuclear Information System (INIS)

    Lam, Hayley; Patel, Shyam; Wong, Janelle; Chu, Julia; Li, Adrian; Li, Song

    2008-01-01

    Human embryonic stem cells (hESC) are pluripotent, and can be directed to differentiate into different cell types for therapeutic applications. To expand hESCs, it is desirable to maintain hESC growth without differentiation. As hESC colonies grow, differentiated cells are often found at the periphery of the colonies, but the underlying mechanism is not well understood. Here, we utilized micropatterning techniques to pattern circular islands or strips of matrix proteins, and examined the spatial pattern of hESC renewal and differentiation. We found that micropatterned matrix restricted hESC differentiation at colony periphery but allowed hESC growth into multiple layers in the central region, which decreased hESC proliferation and induced hESC differentiation. In undifferentiated hESCs, β-catenin primarily localized at cell-cell junctions but not in the nucleus. The amount of β-catenin in differentiating hESCs at the periphery of colonies or in multiple layers decreased significantly at cell-cell junctions. Consistently, knocking down β-catenin decreased Oct-4 expression in hESCs. These results indicate that localized decrease of β-catenin contributes to the spatial pattern of differentiation in hESC colonies

  18. 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

  19. Genetic Variants in the Wnt/β-Catenin Signaling Pathway as Indicators of Bladder Cancer Risk.

    Science.gov (United States)

    Pierzynski, Jeanne A; Hildebrandt, Michelle A; Kamat, Ashish M; Lin, Jie; Ye, Yuanqing; Dinney, Colin P N; Wu, Xifeng

    2015-12-01

    Genetic factors that influence bladder cancer risk remain largely unknown. Previous research has suggested that there is a strong genetic component underlying the risk of bladder cancer. The Wnt/β-catenin signaling pathway is a key modulator of cellular proliferation through its regulation of stem cell homeostasis. Furthermore, variants in the Wnt/β-catenin signaling pathway have been implicated in the development of other cancers, leading us to believe that this pathway may have a vital role in bladder cancer development. A total of 230 single nucleotide polymorphisms in 40 genes in the Wnt/β-catenin signaling pathway were genotyped in 803 bladder cancer cases and 803 healthy controls. A total of 20 single nucleotide polymorphisms were nominally significant for risk. Individuals with 2 variants of LRP6: rs10743980 were associated with a decreased risk of bladder cancer in the recessive model in the initial analysis (OR 0.76, 95% CI 0.58-0.99, p=0.039). This was validated using the bladder genome-wide association study chip (OR 0.51, 95% CI 0.27-1.00, p=0.049 and for combined analysis p=0.007). Together these findings implicate variants in the Wnt/β-catenin stem cell pathway as having a role in bladder cancer etiology. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Compartmentalized Epidermal Activation of β-Catenin Differentially Affects Lineage Reprogramming and Underlies Tumor Heterogeneity

    Directory of Open Access Journals (Sweden)

    Kai Kretzschmar

    2016-01-01

    Full Text Available Wnt/β-catenin activation in adult epidermis can induce new hair follicle formation and tumor development. We used lineage tracing to uncover the relative contribution of different stem cell populations. LGR6+ and LRIG1+ stem cells contributed to ectopic hair follicles formed in the sebaceous gland upon β-catenin activation, whereas LGR5+ cells did not. Lgr6, but not Lrig1 or Lgr5, was expressed in a subpopulation of interfollicular epidermal cells that were competent to form new hair follicles. Oncogenic β-catenin expression in LGR5+ cells led to formation of pilomatricomas, while LRIG1+ cells formed trichoadenomas and LGR6+ cells formed dermatofibromas. Tumor formation was always accompanied by a local increase in dermal fibroblast density and transient extracellular matrix remodeling. However, each tumor had a distinct stromal signature in terms of immune cell infiltrate and expression of CD26 and CD44. We conclude that compartmentalization of epidermal stem cells underlies different responses to β-catenin and skin tumor heterogeneity.

  1. β-catenin is required for prostate development and cooperates with Pten loss to drive invasive carcinoma.

    Directory of Open Access Journals (Sweden)

    Jeffrey C Francis

    Full Text Available Prostate cancer is a major cause of male death in the Western world, but few frequent genetic alterations that drive prostate cancer initiation and progression have been identified. β-Catenin is essential for many developmental processes and has been implicated in tumorigenesis in many tissues, including prostate cancer. However, expression studies on human prostate cancer samples are unclear on the role this protein plays in this disease. We have used in vivo genetic studies in the embryo and adult to extend our understanding of the role of β-Catenin in the normal and neoplastic prostate. Our gene deletion analysis revealed that prostate epithelial β-Catenin is required for embryonic prostate growth and branching but is dispensable in the normal adult organ. During development, β-Catenin controls the number of progenitors in the epithelial buds and regulates a discrete network of genes, including c-Myc and Nkx3.1. Deletion of β-Catenin in a Pten deleted model of castration-resistant prostate cancer demonstrated it is dispensable for disease progression in this setting. Complementary overexpression experiments, through in vivo protein stabilization, showed that β-Catenin promotes the formation of squamous epithelia during prostate development, even in the absence of androgens. β-Catenin overexpression in combination with Pten loss was able to drive progression to invasive carcinoma together with squamous metaplasia. These studies demonstrate that β-Catenin is essential for prostate development and that an inherent property of high levels of this protein in prostate epithelia is to drive squamous fate differentiation. In addition, they show that β-Catenin overexpression can promote invasive prostate cancer in a clinically relevant model of this disease. These data provide novel information on cancer progression pathways that give rise to lethal prostate disease in humans.

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

    Directory of Open Access Journals (Sweden)

    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

  3. Destabilization of Heterologous Proteins Mediated by the GSK3β Phosphorylation Domain of the β-Catenin Protein

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  6. 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

  7. EZH2 Impairs Human Dental Pulp Cell Mineralization via the Wnt/β-Catenin Pathway.

    Science.gov (United States)

    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.

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

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    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.

  9. β-Catenin promotes colitis and colon cancer through imprinting of proinflammatory properties in T cells.

    Science.gov (United States)

    Keerthivasan, Shilpa; Aghajani, Katayoun; Dose, Marei; Molinero, Luciana; Khan, Mohammad W; Venkateswaran, Vysak; Weber, Christopher; Emmanuel, Akinola Olumide; Sun, Tianjao; Bentrem, David J; Mulcahy, Mary; Keshavarzian, Ali; Ramos, Elena M; Blatner, Nichole; Khazaie, Khashayarsha; Gounari, Fotini

    2014-02-26

    The density and type of lymphocytes that infiltrate colon tumors are predictive of the clinical outcome of colon cancer. High densities of T helper 17 (T(H)17) cells and inflammation predict poor outcome, whereas infiltration by T regulatory cells (Tregs) that naturally suppress inflammation is associated with longer patient survival. However, the role of Tregs in cancer remains controversial. We recently reported that Tregs in colon cancer patients can become proinflammatory and tumor-promoting. These properties were directly linked with their expression of RORγt (retinoic acid-related orphan receptor-γt), the signature transcription factor of T(H)17 cells. We report that Wnt/β-catenin signaling in T cells promotes expression of RORγt. Expression of β-catenin was elevated in T cells, including Tregs, of patients with colon cancer. Genetically engineered activation of β-catenin in mouse T cells resulted in enhanced chromatin accessibility in the proximity of T cell factor-1 (Tcf-1) binding sites genome-wide, induced expression of T(H)17 signature genes including RORγt, and promoted T(H)17-mediated inflammation. Strikingly, the mice had inflammation of small intestine and colon and developed lesions indistinguishable from colitis-induced cancer. Activation of β-catenin only in Tregs was sufficient to produce inflammation and initiate cancer. On the basis of these findings, we conclude that activation of Wnt/β-catenin signaling in effector T cells and/or Tregs is causatively linked with the imprinting of proinflammatory properties and the promotion of colon cancer.

  10. Wnt/β-catenin signalling pathway mediated aberrant hippocampal neurogenesis in kainic acid-induced epilepsy.

    Science.gov (United States)

    Qu, Zhengyi; Su, Fang; Qi, Xueting; Sun, Jianbo; Wang, Hongcai; Qiao, Zhenkui; Zhao, Hong; Zhu, Yulan

    2017-10-01

    Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/β-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of β-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down β-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/β-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/β-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Liver X receptor activation inhibits PC-3 prostate cancer cells via the beta-catenin pathway.

    Science.gov (United States)

    Youlin, Kuang; Li, Zhang; Weiyang, He; Jian, Kang; Siming, Liang; Xin, Gou

    2017-03-01

    Liver X receptors (LXRs) are nuclear receptors family of ligand-dependent transcription factors that play a crucial role in regulating cholesterol metabolism and inflammation. Recent studies show that LXR agonists exhibit anti-cancer activities in a variety of cancer cell lines including prostate. To further identify the potential mechanisms of LXRα activation on prostate cancer, we investigated the effect of LXR agonist T0901317 on PC3 prostate cancer cell and in which activity of beta-catenin pathway involved. Prostate cancer PC3 cells were transfected with LXR-a siRNA and treated with LXR activator T0901317. qRT-PCR and western blot were used to detect the LXR-a expression. beta-catenin, cyclin D1 and c-MYC were analyzed by western blot. Cell apoptosis was examined by flow cytometry and Cell proliferation was assessed by Cell Counting Kit-8 assay. Cell migration was detected by Transwell chambers. Data showed that T0901317 significantly inhibited PC3 cell proliferation as well as invasion and increased apoptosis in vitro. Furthermore, we found that LXRα activation induced the reduction of beta-catenin expression in PC3 cells, and this inhibitory effect could be totally abolished when cells were treated with LXRα. Meanwhile, the expression of beta-catenin target gene cyclin D1 and c-MYC were also decreased. This study provided additional evidence that LXR activation inhibited PC-3 prostate cancer cells via suppressing beta-catenin pathway. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. 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

  13. 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

  14. 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.

  15. Frequent β-catenin gene mutations in atypical polypoid adenomyoma of the uterus.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

    Science.gov (United States)

    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.

  18. Stimulation of Na{sup +}/K{sup +} ATPase activity and Na{sup +} coupled glucose transport by {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Sopjani, Mentor [Department of Physiology, University of Tuebingen (Germany); Department of Chemistry, University of Prishtina, Kosovo (Country Unknown); Alesutan, Ioana; Wilmes, Jan [Department of Physiology, University of Tuebingen (Germany); Dermaku-Sopjani, Miribane [Department of Physiology, University of Tuebingen (Germany); Faculty of Medicine, University of Prishtina, Kosovo (Country Unknown); Lam, Rebecca S. [Department of Physiology, University of Tuebingen (Germany); Department of Molecular Neurogenetics, Max Planck Institute of Biophysics, Frankfurt/Main (Germany); Koutsouki, Evgenia [Department of Physiology, University of Tuebingen (Germany); Jakupi, Muharrem [Faculty of Medicine, University of Prishtina, Kosovo (Country Unknown); Foeller, Michael [Department of Physiology, University of Tuebingen (Germany); Lang, Florian, E-mail: florian.lang@uni-tuebingen.de [Department of Physiology, University of Tuebingen (Germany)

    2010-11-19

    Research highlights: {yields} The oncogenic transcription factor {beta}-catenin stimulates the Na{sup +}/K{sup +}-ATPase. {yields} {beta}-Catenin stimulates SGLT1 dependent Na{sup +}, glucose cotransport. {yields} The effects are independent of transcription. {yields} {beta}-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: {beta}-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. {beta}-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 {beta}-catenin influences membrane transport. To this end, {beta}-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of {beta}-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na{sup +}/K{sup +}-ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of {beta}-catenin on the endogenous Na{sup +}/K{sup +}-ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of {beta}-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of {beta}-catenin expression. The stimulating effect of {beta}-catenin on both Na{sup +}/K{sup +} 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 {beta}-catenin, i.e. the regulation of transport.

  19. Isoreserpine promotes {beta}-catenin degradation via Siah-1 up-regulation in HCT116 colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Gwak, Jungsug; Song, Taeyun [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Jie-Young; Yun, Yeon-Sook [Laboratory of Radiation Cancer Science, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Choi, Il-Whan [Department of Microbiology, Center for Viral Disease Research, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Jeong, Yongsu [Department of Genetic Engineering, and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Department of Clinical Pharmacology, Inje University Busan Paik Hospital, Busan 614-735 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

    2009-09-25

    Aberrant accumulation of intracellular {beta}-catenin in intestinal epithelial cells is a frequent early event during the development of colon cancer. To identify small molecules that decrease the level of intracellular {beta}-catenin, we performed cell-based chemical screening using genetically engineered HEK293 reporter cells to detect compounds that inhibit TOPFlash reporter activity, which was stimulated by Wnt3a-conditioned medium. We found that isoreserpine promoted the degradation of intracellular {beta}-catenin by up-regulation of Siah-1 in HEK293 and HCT116 colon cancer cells. Moreover, isoreserpine repressed the expression of {beta}-catenin/T-cell factor (TCF)-dependent genes, such as cyclin D1 and c-myc, resulting in the suppression of HCT116 cell proliferation. Our findings suggest that isoreserpine can potentially be used as a chemotherapeutic agent against colon cancer.

  20. 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.

  1. 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.

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

    Science.gov (United States)

    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/β-catenin pathway in adult mouse neural stem cells. Furthermore, we demonstrate that Wnt/β-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 β-catenin promote neural stem cell self-renewal, whereas the deletion of Wnt7a or the lentiviral transduction of axin, a β-catenin inhibitor, led to decreased cell proliferation in adult neurogenic areas. Lentiviral transduction of active β-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 β-catenin significantly rescued a TLX (also known as Nr2e1) short interfering RNA-induced deficiency in neural stem cell proliferation. Lentiviral transduction of an active β-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/β-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. PMID:20010817

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

    Science.gov (United States)

    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.

  4. ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xinhua [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Wang, Xiaoyuan [Department of Nephrology, Xi An Honghui Hospital, Xi an (China); Hu, Xiongke; Chen, Yong; Zeng, Kefeng [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China); Zhang, Hongqi, E-mail: zhq9699@126.com [Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha (China)

    2015-07-01

    Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression.

  5. ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

    International Nuclear Information System (INIS)

    Yin, Xinhua; Wang, Xiaoyuan; Hu, Xiongke; Chen, Yong; Zeng, Kefeng; Zhang, Hongqi

    2015-01-01

    Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression

  6. 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.

  7. β-catenin is selectively required for the expansion and regeneration of mature pancreatic acinar cells in mice

    Directory of Open Access Journals (Sweden)

    Matthew D. Keefe

    2012-07-01

    The size of the pancreas is determined by intrinsic factors, such as the number of progenitor cells, and by extrinsic signals that control the fate and proliferation of those progenitors. Both the exocrine and endocrine compartments of the pancreas undergo dramatic expansion after birth and are capable of at least partial regeneration following injury. Whether the expansion of these lineages relies on similar mechanisms is unknown. Although we have shown that the Wnt signaling component β-catenin is selectively required in mouse embryos for the generation of exocrine acinar cells, this protein has been ascribed various functions in the postnatal pancreas, including proliferation and regeneration of islet as well as acinar cells. To address whether β-catenin remains important for the maintenance and expansion of mature acinar cells, we have established a system to follow the behavior and fate of β-catenin-deficient cells during postnatal growth and regeneration in mice. We find that β-catenin is continuously required for the establishment and maintenance of acinar cell mass, extending from embryonic specification through juvenile and adult self-renewal and regeneration. This requirement is not shared with islet cells, which proliferate and function normally in the absence of β-catenin. These results make distinct predictions for the relative role of Wnt–β-catenin signaling in the etiology of human endocrine and exocrine disease. We suggest that loss of Wnt–β-catenin activity is unlikely to drive islet dysfunction, as occurs in type 2 diabetes, but that β-catenin is likely to promote human acinar cell proliferation following injury, and might therefore contribute to the resolution of acute or chronic pancreatitis.

  8. 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.

  9. β-Catenin stabilization imparts crypt progenitor phenotype to hyperproliferating colonic epithelia

    International Nuclear Information System (INIS)

    Sellin, Joseph H.; Wang Yu; Singh, Pomila; Umar, Shahid

    2009-01-01

    Utilizing the Citrobacter rodentium (CR)-induced transmissible murine colonic hyperplasia (TMCH) model, we provide mechanistic basis of changes in β-catenin/APC/CKIε leading to progression and/or regression of hyperplasia in vivo. In response to CR-induced TMCH, crypt lengths increased significantly between days 6-27 post-infection, followed by a steep decline by day 34. β-Cat 45 /total β-catenin were elevated on day 1 post-infection, preceding changes in crypt length, and persisted for 27 days before declining by day 34. Importantly, cellular CKIε and β-catenin co-immunoprecipitated and exhibited remarkable parallel changes in kinetics during hyperplasia/regression phases. β-catenin, phosphorylated at Ser33,37 and Thr41 (β-cat 33,37/41 ), was low till day 12, followed by gradual increase until day 27 before declining by day 34. GSK-3β exhibited significant Ser 9 -phosphorylation/inactivation at days 6-12 with partial recovery at days 27-34. Wild type (wt) APC (p312) levels increased at day 6 with transient proteolysis/truncation to p130 form between days 12 and 15; p312 reappeared by day 19 and returned to baseline by day 34. The kinetics of β-Cat 45 /β-catenin nuclear accumulation and acetylation (Ac-β-Cat Lys49 ) from days 6 to 27, followed by loss of phosphorylation/acetylation by day 34 was almost identical; Tcf-4 co-immunoprecipitated with β-Cat 45 /β-catenin and localized immunohistochemically to β-Cat 41/45 -positive regions leading to elevated cyclin D1 expression, during the hyperproliferative, but not regression phases of TMCH. CKIε mediated phosphorylation of β-Cat 45 , resulting in stabilization/nuclear translocation of β-Cat 45 may be critical for maintaining proliferation at days 6-27. Reversal of GSK-3β phosphorylation and APC changes may be equally critical during the regression phase from days 27 to 34

  10. Cadherin-Catenin Complex Dissociation in Lobular Neoplasia of the Breast

    Science.gov (United States)

    Morrogh, Mary; Andrade, Victor P.; Giri, Dilip; Sakr, Rita A.; Paik, Wooyul; Qin, Li-Xuan; Arroyo, Crispinita D.; Brogi, Edi; Morrow, Monica; King, Tari A.

    2015-01-01

    Background E-cadherin (E-CD) inactivation with loss of E-CD-mediated cell adhesion is the hallmark of lesions of the lobular phenotype. E-CD is typically absent by immunohistochemistry in both lobular carcinoma in situ (LCIS) and invasive lobular lesions, suggesting it occurs early in the neoplastic process. In laboratory models, downstream post-transcriptional modifiers such as TWIST and SNAIL contribute to the dissociation of the intracellular component of the cadherin-catenin complex (CCC), resulting in tumor progression and invasion. We hypothesized that complete CCC dissociation may play a role in lobular neoplasia progression. Here we explore the relationship between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS associated with invasive cancer. Methods Fresh-frozen tissues were obtained from 36 patients undergoing mastectomy for pure LCIS (n=11), LCIS with ILC (n=18) or LCIS with IDC (n=7). Individual lesions were subject to laser-capture microdissection and gene-expression analysis (Affymetrix HG-U133A 2.0). Immunohistochemistry for ER,PR,HER2, E-CD,N-CD,α-,β-, and phosphoβ-catenin, TWIST, and SNAIL were evaluated in normal, in situ, and invasive components from matched formalin-fixed paraffin-embedded samples(n=36). CCC-dissociation was defined as negative membranous E-CD, α- and β-catenin expression. Results E-CD was negative in all LCIS and ILC lesions, and positive in all normal and IDC lesions. Membranous α and β-catenin expression decreased with the transition from LCIS to ILC (pure LCIS 82%;LCIS w/ILC 28%;ILC 0%), while TWIST expression increased (pure LCIS low;LCIS w/ILC moderate;ILC high). Gene expression paralleled IHC staining patterns with a stepwise downregulation of E-CD, α and β-catenin from normal to LCIS to invasive lesions, and increasing expression of TWIST from normal to LCIS to ILC. Conclusions Loss of E-CD expression is an early event in lobular neoplasia. Decreasing membranous catenin expression in tandem with

  11. Neuroprotective effect of rapamycin on spinal cord injury via activation of the Wnt/β-catenin signaling pathway

    Directory of Open Access Journals (Sweden)

    Kai Gao

    2015-01-01

    Full Text Available The Wnt/β-catenin signaling pathway plays a crucial role in neural development, axonal guidance, neuropathic pain remission and neuronal survival. In this study, we initially examined the effect of rapamycin on the Wnt/β-catenin signaling pathway after spinal cord injury, by intraperitoneally injecting spinal cord injured rats with rapamycin over 2 days. Western blot analysis and immunofluorescence staining were used to detect the expression levels of β-catenin protein, ca-spase-3 protein and brain-derived neurotrophic factor protein, components of the Wnt/β-catenin signaling pathway. Rapamycin increased the levels of β-catenin and brain-derived neurotrophic factor in the injured spinal cord, improved the pathological morphology at the injury site, reduced the loss of motor neurons, and promoted motor functional recovery in rats after spinal cord injury. Our experimental findings suggest that the neuroprotective effect of rapamycin intervention is mediated through activation of the Wnt/β-catenin signaling pathway after spinal cord injury.

  12. 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.

  13. 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.

  14. Acetaldehyde dissociates the PTP1B–E-cadherin–β-catenin complex in Caco-2 cell monolayers by a phosphorylation-dependent mechanism

    Science.gov (United States)

    Sheth, Parimal; Seth, Ankur; Atkinson, Katherine J.; Gheyi, Tarun; Kale, Gautam; Giorgianni, Francesco; Desiderio, Dominic M.; Li, Chunying; Naren, Anjaparavanda; Rao, Radhakrishna

    2006-01-01

    Interactions between E-cadherin, β-catenin and PTP1B (protein tyrosine phosphatase 1B) are crucial for the organization of AJs (adherens junctions) and epithelial cell–cell adhesion. In the present study, the effect of acetaldehyde on the AJs and on the interactions between E-cadherin, β-catenin and PTP1B was determined in Caco-2 cell monolayers. Treatment of cell monolayers with acetaldehyde induced redistribution of E-cadherin and β-catenin from the intercellular junctions by a tyrosine phosphorylation-dependent mechanism. The PTPase activity associated with E-cadherin and β-catenin was significantly reduced and the interaction of PTP1B with E-cadherin and β-catenin was attenuated by acetaldehyde. Acetaldehyde treatment resulted in phosphorylation of β-catenin on tyrosine residues, and abolished the interaction of β-catenin with E-cadherin by a tyrosine kinase-dependent mechanism. Protein binding studies showed that the treatment of cells with acetaldehyde reduced the binding of β-catenin to the C-terminal region of E-cadherin. Pairwise binding studies using purified proteins indicated that the direct interaction between E-cadherin and β-catenin was reduced by tyrosine phosphorylation of β-catenin, but was unaffected by tyrosine phosphorylation of E-cadherin-C. Treatment of cells with acetaldehyde also reduced the binding of E-cadherin to GST (glutathione S-transferase)–PTP1B. The pairwise binding study showed that GST–E-cadherin-C binds to recombinant PTP1B, but this binding was significantly reduced by tyrosine phosphorylation of E-cadherin. Acetaldehyde increased the phosphorylation of β-catenin on Tyr-331, Tyr-333, Tyr-654 and Tyr-670. These results show that acetaldehyde induces disruption of interactions between E-cadherin, β-catenin and PTP1B by a phosphorylation-dependent mechanism. PMID:17087658

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. 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.

  17. The time point of β-catenin knockout in hepatocytes determines their response to xenobiotic activation of the constitutive androstane receptor

    International Nuclear Information System (INIS)

    Ganzenberg, Katrin; Singh, Yasmin; Braeuning, Albert

    2013-01-01

    The constitutive androstane receptor (CAR) controls the expression of drug-metabolizing enzymes and regulates hepatocyte proliferation. Studies with transgenic mice with an early postnatal conditional hepatocyte-specific knockout of the β-catenin gene Ctnnb1 revealed that β-catenin deficiency decreases the magnitude of induction of drug-metabolizing enzymes by CAR activators, abrogates zonal differences in the hepatocytes’ susceptibility to these compounds, and impacts on hepatocyte proliferation. These data, however, do not allow distinguishing between effects caused by β-catenin deficiency during postnatal liver development and acute effects of β-catenin deficiency in the adult animal at the time point of CAR activation. Therefore, CAR activation was now studied in a different mouse model allowing for the hepatocyte-specific knockout of β-catenin in adult mice. Treatment of these mice with 3 mg/kg body weight of the model CAR activator 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) confirmed previous findings related to the coordinate regulation of drug metabolism by β-catenin and CAR. More importantly, the present study clarified that the impact of β-catenin signaling on CAR-mediated enzyme induction in the liver is not merely due to developmental defects caused by a postnatal lack of β-catenin, but depends on the presence of β-catenin at the time point of xenobiotic treatment. The study also revealed interesting differences between the two mouse models: hepatic zonation of TCPOBOP-dependent induction of drug-metabolizing enzymes was restored in mice with late knockout of β-catenin, and the strong proliferative response of female mice was exclusively abolished when using animals with a late β-catenin knockout. This suggests a β-catenin-dependent postnatal priming of hepatocytes during postnatal liver development, later affecting the proliferative response of adult animals to CAR-activating xenobiotics

  18. 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

  19. Lentiviral Modulation of Wnt/β-Catenin Signaling Affects In Vivo LTP.

    Science.gov (United States)

    Ivanova, Olga Ya; Dobryakova, Yulia V; Salozhin, Sergey V; Aniol, Viktor A; Onufriev, Mikhail V; Gulyaeva, Natalia V; Markevich, Vladimir A

    2017-10-01

    Wnt signaling is involved in hippocampal development and synaptogenesis. Numerous recent studies have been focused on the role of Wnt ligands in the regulation of synaptic plasticity. Inhibitors and activators of canonical Wnt signaling were demonstrated to decrease or increase, respectively, in vitro long-term potentiation (LTP) maintenance in hippocampal slices (Chen et al. in J Biol Chem 281:11910-11916, 2006; Vargas et al. in J Neurosci 34:2191-2202, 2014, Vargas et al. in Exp Neurol 264:14-25, 2015). Using lentiviral approach to down- and up-regulate the canonical Wnt signaling, we explored whether Wnt/β-catenin signaling is critical for the in vivo LTP. Chronic suppression of Wnt signaling induced an impairment of in vivo LTP expression 14 days after lentiviral suspension injection, while overexpression of Wnt3 was associated with a transient enhancement of in vivo LTP magnitude. Both effects were related to the early phase LTP and did not affect LTP maintenance. A loss-of-function study demonstrated decreased initial paired pulse facilitation ratio, β-catenin, and phGSK-3β levels. A gain-of-function study revealed not only an increase in PSD-95, β-catenin, and Cyclin D1 protein levels, but also a reduced phGSK-3β level and enhanced GSK-3β kinase activity. These results suggest a presynaptic dysfunction predominantly underlying LTP impairment while postsynaptic modifications are primarily involved in transient LTP amplification. This study is the first demonstration of the involvement of Wnt/β-catenin signaling in synaptic plasticity regulation in an in vivo LTP model.

  20. Concurrent Transient Activation of Wnt/β-Catenin Pathway Prevents Radiation Damage to Salivary Glands

    International Nuclear Information System (INIS)

    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.

  1. 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.

  2. 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

  3. Catenin-dependent cadherin function drives divisional segregation of spinal motor neurons.

    Science.gov (United States)

    Bello, Sanusi M; Millo, Hadas; Rajebhosale, Manisha; Price, Stephen R

    2012-01-11

    Motor neurons that control limb movements are organized as a neuronal nucleus in the developing ventral horn of the spinal cord called the lateral motor column. Neuronal migration segregates motor neurons into distinct lateral and medial divisions within the lateral motor column that project axons to dorsal or ventral limb targets, respectively. This migratory phase is followed by an aggregation phase whereby motor neurons within a division that project to the same muscle cluster together. These later phases of motor neuron organization depend on limb-regulated differential cadherin expression within motor neurons. Initially, all motor neurons display the same cadherin expression profile, which coincides with the migratory phase of motor neuron segregation. Here, we show that this early, pan-motor neuron cadherin function drives the divisional segregation of spinal motor neurons in the chicken embryo by controlling motor neuron migration. We manipulated pan-motor neuron cadherin function through dissociation of cadherin binding to their intracellular partners. We found that of the major intracellular transducers of cadherin signaling, γ-catenin and α-catenin predominate in the lateral motor column. In vivo manipulations that uncouple cadherin-catenin binding disrupt divisional segregation via deficits in motor neuron migration. Additionally, reduction of the expression of cadherin-7, a cadherin predominantly expressed in motor neurons only during their migration, also perturbs divisional segregation. Our results show that γ-catenin-dependent cadherin function is required for spinal motor neuron migration and divisional segregation and suggest a prolonged role for cadherin expression in all phases of motor neuron organization.

  4. 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

  5. Early Transcriptional Changes Induced by Wnt/β-Catenin Signaling in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Eduardo Pérez-Palma

    2016-01-01

    Full Text Available Wnt/β-catenin signaling modulates brain development and function and its deregulation underlies pathological changes occurring in neurodegenerative and neurodevelopmental disorders. Since one of the main effects of Wnt/β-catenin signaling is the modulation of target genes, in the present work we examined global transcriptional changes induced by short-term Wnt3a treatment (4 h in primary cultures of rat hippocampal neurons. RNAseq experiments allowed the identification of 170 differentially expressed genes, including known Wnt/β-catenin target genes such as Notum, Axin2, and Lef1, as well as novel potential candidates Fam84a, Stk32a, and Itga9. Main biological processes enriched with differentially expressed genes included neural precursor (GO:0061364, p-adjusted = 2.5 × 10−7, forebrain development (GO:0030900, p-adjusted = 7.3 × 10−7, and stem cell differentiation (GO:0048863 p-adjusted = 7.3 × 10−7. Likewise, following activation of the signaling cascade, the expression of a significant number of genes with transcription factor activity (GO:0043565, p-adjusted = 4.1 × 10−6 was induced. We also studied molecular networks enriched upon Wnt3a activation and detected three highly significant expression modules involved in glycerolipid metabolic process (GO:0046486, p-adjusted = 4.5 × 10−19, learning or memory (GO:0007611, p-adjusted = 4.0 × 10−5, and neurotransmitter secretion (GO:0007269, p-adjusted = 5.3 × 10−12. Our results indicate that Wnt/β-catenin mediated transcription controls multiple biological processes related to neuronal structure and activity that are affected in synaptic dysfunction disorders.

  6. Decreased nuclear β-catenin, tau hyperphosphorylation and neurodegeneration in GSK-3β conditional transgenic mice

    OpenAIRE

    Lucas, José J.; Hernández, Félix; Gómez-Ramos, Pilar; Morán, María A.; Hen, René; Avila, Jesús

    2001-01-01

    Glycogen synthase kinase-3β (GSK-3β) has been postulated to mediate Alzheimer’s disease tau hyperphosphorylation, β-amyloid-induced neurotoxicity and presenilin-1 mutation pathogenic effects. By using the tet-regulated system we have produced conditional transgenic mice overexpressing GSK-3β in the brain during adulthood while avoiding perinatal lethality due to embryonic transgene expression. These mice show decreased levels of nuclear β-catenin and hyperphosphorylation of tau in hippocampal...

  7. Identification of Androgen Receptor and Beta-Catenin Target Genes in Prostate and Prostate Cancer

    Science.gov (United States)

    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

  8. β-Catenin signaling regulates temporally discrete phases of anterior taste bud development

    OpenAIRE

    Thirumangalathu, Shoba; Barlow, Linda A.

    2015-01-01

    The sense of taste is mediated by multicellular taste buds located within taste papillae on the tongue. In mice, individual taste buds reside in fungiform papillae, which develop at mid-gestation as epithelial placodes in the anterior tongue. Taste placodes comprise taste bud precursor cells, which express the secreted factor sonic hedgehog (Shh) and give rise to taste bud cells that differentiate around birth. We showed previously that epithelial activation of β-catenin is the primary induct...

  9. 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

  10. Alteration of astrocytes and Wnt/β-catenin signaling in the frontal cortex of autistic subjects

    Directory of Open Access Journals (Sweden)

    Cao Fujiang

    2012-09-01

    Full Text Available Abstract Background Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. To date the etiology of this disorder is poorly understood. Studies suggest that astrocytes play critical roles in neural plasticity by detecting neuronal activity and modulating neuronal networks. Recently, a number of studies suggested that an abnormal function of glia/astrocytes may be involved in the development of autism. However, there is yet no direct evidence showing how astrocytes develop in the brain of autistic individuals. Methods Study subjects include brain tissue from autistic subjects, BTBR T + tfJ (BTBR and Neuroligin (NL-3 knock-down mice. Western blot analysis, Immunohistochemistry and confocal microscopy studies have be used to examine the density and morphology of astrocytes, as well as Wnt and β-catenin protein expression. Results In this study, we demonstrate that the astrocytes in autisitcsubjects exhibit significantly reduced branching processes, total branching length and cell body sizes. We also detected an astrocytosis in the frontal cortex of autistic subjects. In addition, we found that the astrocytes in the brain of an NL3 knockdown mouse exhibited similar alterations to what we found in the autistic brain. Furthermore, we detected that both Wnt and β-catenin proteins are decreased in the frontal cortex of autistic subjects. Wnt/β-catenin pathway has been suggested to be involved in the regulation of astrocyte development. Conclusions Our findings imply that defects in astrocytes could impair neuronal plasticity and partially contribute to the development of autistic-like behaviors in both humans and mice. The alteration of Wnt/β-catenin pathway in the brain of autistic subjects may contribute to the changes of astrocytes.

  11. Rac1 augments Wnt signaling by stimulating β-catenin–lymphoid enhancer factor-1 complex assembly independent of β-catenin nuclear import

    Science.gov (United States)

    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

  12. 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

  13. Linc00210 drives Wnt/β-catenin signaling activation and liver tumor progression through CTNNBIP1-dependent manner.

    Science.gov (United States)

    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

  14. Temporal Regulation of Natural Killer T Cell Interferon Gamma Responses by β-Catenin-Dependent and -Independent Wnt Signaling.

    Science.gov (United States)

    Kling, Jessica C; Jordan, Margaret A; Pitt, Lauren A; Meiners, Jana; Thanh-Tran, Thao; Tran, Le Son; Nguyen, Tam T K; Mittal, Deepak; Villani, Rehan; Steptoe, Raymond J; Khosrotehrani, Kiarash; Berzins, Stuart P; Baxter, Alan G; Godfrey, Dale I; Blumenthal, Antje

    2018-01-01

    Natural killer T (NKT) cells are prominent innate-like lymphocytes in the liver with critical roles in immune responses during infection, cancer, and autoimmunity. Interferon gamma (IFN-γ) and IL-4 are key cytokines rapidly produced by NKT cells upon recognition of glycolipid antigens presented by antigen-presenting cells (APCs). It has previously been reported that the transcriptional coactivator β-catenin regulates NKT cell differentiation and functionally biases NKT cell responses toward IL-4, at the expense of IFN-γ production. β-Catenin is not only a central effector of Wnt signaling but also contributes to other signaling networks. It is currently unknown whether Wnt ligands regulate NKT cell functions. We thus investigated how Wnt ligands and β-catenin activity shape liver NKT cell functions in vivo in response to the glycolipid antigen, α-galactosylceramide (α-GalCer) using a mouse model. Pharmacologic targeting of β-catenin activity with ICG001, as well as myeloid-specific genetic ablation of Wntless (Wls) , to specifically target Wnt protein release by APCs, enhanced early IFN-γ responses. By contrast, within several hours of α-GalCer challenge, myeloid-specific Wls deficiency, as well as pharmacologic targeting of Wnt release using the small molecule inhibitor IWP-2 impaired α-GalCer-induced IFN-γ responses, independent of β-catenin activity. These data suggest that myeloid cell-derived Wnt ligands drive early Wnt/β-catenin signaling that curbs IFN-γ responses, but that, subsequently, Wnt ligands sustain IFN-γ expression independent of β-catenin activity. Our analyses in ICG001-treated mice confirmed a role for β-catenin activity in driving early IL-4 responses by liver NKT cells. However, neither pharmacologic nor genetic perturbation of Wnt production affected the IL-4 response, suggesting that IL-4 production by NKT cells in response to α-GalCer is not driven by released Wnt ligands. Collectively, these data reveal complex temporal

  15. Temporal Regulation of Natural Killer T Cell Interferon Gamma Responses by β-Catenin-Dependent and -Independent Wnt Signaling

    Directory of Open Access Journals (Sweden)

    Jessica C. Kling

    2018-03-01

    Full Text Available Natural killer T (NKT cells are prominent innate-like lymphocytes in the liver with critical roles in immune responses during infection, cancer, and autoimmunity. Interferon gamma (IFN-γ and IL-4 are key cytokines rapidly produced by NKT cells upon recognition of glycolipid antigens presented by antigen-presenting cells (APCs. It has previously been reported that the transcriptional coactivator β-catenin regulates NKT cell differentiation and functionally biases NKT cell responses toward IL-4, at the expense of IFN-γ production. β-Catenin is not only a central effector of Wnt signaling but also contributes to other signaling networks. It is currently unknown whether Wnt ligands regulate NKT cell functions. We thus investigated how Wnt ligands and β-catenin activity shape liver NKT cell functions in vivo in response to the glycolipid antigen, α-galactosylceramide (α-GalCer using a mouse model. Pharmacologic targeting of β-catenin activity with ICG001, as well as myeloid-specific genetic ablation of Wntless (Wls, to specifically target Wnt protein release by APCs, enhanced early IFN-γ responses. By contrast, within several hours of α-GalCer challenge, myeloid-specific Wls deficiency, as well as pharmacologic targeting of Wnt release using the small molecule inhibitor IWP-2 impaired α-GalCer-induced IFN-γ responses, independent of β-catenin activity. These data suggest that myeloid cell-derived Wnt ligands drive early Wnt/β-catenin signaling that curbs IFN-γ responses, but that, subsequently, Wnt ligands sustain IFN-γ expression independent of β-catenin activity. Our analyses in ICG001-treated mice confirmed a role for β-catenin activity in driving early IL-4 responses by liver NKT cells. However, neither pharmacologic nor genetic perturbation of Wnt production affected the IL-4 response, suggesting that IL-4 production by NKT cells in response to α-GalCer is not driven by released Wnt ligands. Collectively, these data reveal

  16. Toward a quantitative understanding of the Wnt/ β -catenin pathway through simulation and experiment

    KAUST Repository

    Lloyd-Lewis, Bethan

    2013-03-29

    Wnt signaling regulates cell survival, proliferation, and differentiation throughout development and is aberrantly regulated in cancer. The pathway is activated when Wnt ligands bind to specific receptors on the cell surface, resulting in the stabilization and nuclear accumulation of the transcriptional co-activator β-catenin. Mathematical and computational models have been used to study the spatial and temporal regulation of the Wnt/β-catenin pathway and to investigate the functional impact of mutations in key components. Such models range in complexity, from time-dependent, ordinary differential equations that describe the biochemical interactions between key pathway components within a single cell, to complex, multiscale models that incorporate the role of the Wnt/β-catenin pathway target genes in tissue homeostasis and carcinogenesis. This review aims to summarize recent progress in mathematical modeling of the Wnt pathway and to highlight new biological results that could form the basis for future theoretical investigations designed to increase the utility of theoretical models of Wnt signaling in the biomedical arena. © 2013 Wiley Periodicals, Inc.

  17. Mechanical unfolding reveals stable 3-helix intermediates in talin and α-catenin.

    Directory of Open Access Journals (Sweden)

    Vasyl V Mykuliak

    2018-04-01

    Full Text Available Mechanical stability is a key feature in the regulation of structural scaffolding proteins and their functions. Despite the abundance of α-helical structures among the human proteome and their undisputed importance in health and disease, the fundamental principles of their behavior under mechanical load are poorly understood. Talin and α-catenin are two key molecules in focal adhesions and adherens junctions, respectively. In this study, we used a combination of atomistic steered molecular dynamics (SMD simulations, polyprotein engineering, and single-molecule atomic force microscopy (smAFM to investigate unfolding of these proteins. SMD simulations revealed that talin rod α-helix bundles as well as α-catenin α-helix domains unfold through stable 3-helix intermediates. While the 5-helix bundles were found to be mechanically stable, a second stable conformation corresponding to the 3-helix state was revealed. Mechanically weaker 4-helix bundles easily unfolded into a stable 3-helix conformation. The results of smAFM experiments were in agreement with the findings of the computational simulations. The disulfide clamp mutants, designed to protect the stable state, support the 3-helix intermediate model in both experimental and computational setups. As a result, multiple discrete unfolding intermediate states in the talin and α-catenin unfolding pathway were discovered. Better understanding of the mechanical unfolding mechanism of α-helix proteins is a key step towards comprehensive models describing the mechanoregulation of proteins.

  18. 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.

  19. 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.

  20. Epigenetically Aberrant Stroma in MDS Propagates Disease via Wnt/β-Catenin Activation.

    Science.gov (United States)

    Bhagat, Tushar D; Chen, Si; Bartenstein, Matthias; Barlowe, A Trevor; Von Ahrens, Dagny; Choudhary, Gaurav S; Tivnan, Patrick; Amin, Elianna; Marcondes, A Mario; Sanders, Mathijs A; Hoogenboezem, Remco M; Kambhampati, Suman; Ramachandra, Nandini; Mantzaris, Iaonnis; Sukrithan, Vineeth; Laurence, Remi; Lopez, Robert; Bhagat, Prafullla; Giricz, Orsi; Sohal, Davendra; Wickrema, Amittha; Yeung, Cecilia; Gritsman, Kira; Aplan, Peter; Hochedlinger, Konrad; Yu, Yiting; Pradhan, Kith; Zhang, Jinghang; Greally, John M; Mukherjee, Siddhartha; Pellagatti, Andrea; Boultwood, Jacqueline; Will, Britta; Steidl, Ulrich; Raaijmakers, Marc H G P; Deeg, H Joachim; Kharas, Michael G; Verma, Amit

    2017-09-15

    The bone marrow microenvironment influences malignant hematopoiesis, but how it promotes leukemogenesis has not been elucidated. In addition, the role of the bone marrow stroma in regulating clinical responses to DNA methyltransferase inhibitors (DNMTi) is also poorly understood. In this study, we conducted a DNA methylome analysis of bone marrow-derived stromal cells from myelodysplastic syndrome (MDS) patients and observed widespread aberrant cytosine hypermethylation occurring preferentially outside CpG islands. Stroma derived from 5-azacytidine-treated patients lacked aberrant methylation and DNMTi treatment of primary MDS stroma enhanced its ability to support erythroid differentiation. An integrative expression analysis revealed that the WNT pathway antagonist FRZB was aberrantly hypermethylated and underexpressed in MDS stroma. This result was confirmed in an independent set of sorted, primary MDS-derived mesenchymal cells. We documented a WNT/β-catenin activation signature in CD34 + cells from advanced cases of MDS, where it associated with adverse prognosis. Constitutive activation of β-catenin in hematopoietic cells yielded lethal myeloid disease in a NUP98-HOXD13 mouse model of MDS, confirming its role in disease progression. Our results define novel epigenetic changes in the bone marrow microenvironment, which lead to β-catenin activation and disease progression of MDS. Cancer Res; 77(18); 4846-57. ©2017 AACR . ©2017 American Association for Cancer Research.

  1. 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.

  2. An EMMPRIN-γ-catenin-Nm23 complex drives ATP production and actomyosin contractility at endothelial junctions.

    Science.gov (United States)

    Moreno, Vanessa; Gonzalo, Pilar; Gómez-Escudero, Jesús; Pollán, Ángela; Acín-Pérez, Rebeca; Breckenridge, Mark; Yáñez-Mó, María; Barreiro, Olga; Orsenigo, Fabrizio; Kadomatsu, Kenji; Chen, Christopher S; Enríquez, José A; Dejana, Elisabetta; Sánchez-Madrid, Francisco; Arroyo, Alicia G

    2014-09-01

    Cell-cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier strength. We identify the Ig superfamily member EMMPRIN (also known as basigin) as a coordinator of forces at endothelial junctions. EMMPRIN localization at junctions correlates with endothelial junction strength in different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased junction permeability. Lack of EMMPRIN alters the localization and function of VE-cadherin (also known as cadherin-5) by decreasing both actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin (also known as junction plakoglobin) and Nm23 (also known as NME1), a nucleoside diphosphate kinase, thereby locally providing ATP to fuel the actomyosin machinery. These results provide a novel mechanism for the regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly. © 2014. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

    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.

  4. 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.

  5. Interactions between TGF-β1, canonical WNT/β-catenin pathway and PPAR γ in radiation-induced fibrosis.

    Science.gov (United States)

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

    2017-10-27

    Radiation therapy induces DNA damage and inflammation leading to fibrosis. Fibrosis can occur 4 to 12 months after radiation therapy. This process worsens with time and years. Radiation-induced fibrosis is characterized by fibroblasts proliferation, myofibroblast differentiation, and synthesis of collagen, proteoglycans and extracellular matrix. Myofibroblasts are non-muscle cells that can contract and relax. Myofibroblasts evolve towards irreversible retraction during fibrosis process. In this review, we discussed the interplays between transforming growth factor-β1 (TGF-β1), canonical WNT/β-catenin pathway and peroxisome proliferator-activated receptor gamma (PPAR γ) in regulating the molecular mechanisms underlying the radiation-induced fibrosis, and the potential role of PPAR γ agonists. Overexpression of TGF-β and canonical WNT/β-catenin pathway stimulate fibroblasts accumulation and myofibroblast differentiation whereas PPAR γ expression decreases due to the opposite interplay of canonical WNT/β-catenin pathway. Both TGF-β1 and canonical WNT/β-catenin pathway stimulate each other through the Smad pathway and non-Smad pathways such as phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K/Akt) signaling. WNT/β-catenin pathway and PPAR γ interact in an opposite manner. PPAR γ agonists decrease β-catenin levels through activation of inhibitors of the WNT pathway such as Smad7, glycogen synthase kinase-3 (GSK-3 β) and dickkopf-related protein 1 (DKK1). PPAR γ agonists also stimulate phosphatase and tensin homolog (PTEN) expression, which decreases both TGF-β1 and PI3K/Akt pathways. PPAR γ agonists by activating Smad7 decrease Smads pathway and then TGF-β signaling leading to decrease radiation-induced fibrosis. TGF-β1 and canonical WNT/β-catenin pathway promote radiation-induced fibrosis whereas PPAR γ agonists can prevent radiation-induced fibrosis.

  6. 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.

  7. The transcription factor LEF-1 induces an epithelial–mesenchymal transition in MDCK cells independent of β-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Wakako; Ozawa, Masayuki, E-mail: mozawa@m.kufm.kagoshima-u.ac.jp

    2013-12-06

    Highlights: •The transcription factor LEF-1 induces an EMT in MDCK cells. •A mutant LEF-1 that cannot interact with β-catenin retained the ability. •The nuclear function of β-catenin was not necessary for the LEF-1-induced EMT. •The mRNA levels of Slug, ZEB1, and ZEB2 increased significantly in these cells. -- Abstract: The epithelial–mesenchymal transition (EMT), a key process in the tumor metastatic cascade, is characterized by the loss of cell–cell junctions and cell polarity, as well as the acquisition of migratory and invasive properties. LEF-1 is a member of the lymphoid enhancer-binding factor/T-cell factor (LEF/TCF) family of DNA-binding transcription factors, which interact with nuclear β-catenin and act as central transcriptional mediators of Wnt signaling. To investigate the role of LEF-1 in EMT, we generated stable LEF-1 transfectants using MDCK cells. The transfectants had a spindle-shaped mesenchymal morphology, and enhanced migration and invasiveness relative to control cells. These EMT changes were accompanied by the downregulation of an epithelial marker protein, E-cadherin, and the upregulation of mesenchymal marker proteins, vimentin and N-cadherin. Consistent with these observations, the mRNA levels of Slug, ZEB1, and ZEB2—EMT-related transcription factors—increased significantly. Although the N-terminally deleted mutant LEF-1 cannot interact with β-catenin, it retained the ability to induce EMT. Consistent with these observations, neither the expression of a dominant negative β-catenin/engrailed chimera, nor the expression of a cytoplasmic domain of E-cadherin that sequesters β-catenin from binding to LEF/TCF, reversed LEF-1-induced EMT. Together, these data indicated that the nuclear function of β-catenin was not necessary for the induction of Slug, ZEB1, and ZEB2 expression leading to EMT.

  8. 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.

  9. Wnt and β-Catenin Signaling and Skeletal Muscle Myogenesis in Response to Muscle Damage and Resistance Exercise and Training

    Directory of Open Access Journals (Sweden)

    Dan Newmire

    2015-10-01

    Full Text Available The factors that regulate skeletal muscle hypertrophy in human adults in response to resistance training (RT has largely focused on endogenous endocrine responses. However, the endocrine response to RT as having an obligatory role in muscle hypertrophy has come under scrutiny, as other mechanisms and pathways seem to also be involved in up-regulating muscle protein synthesis (MPS. Skeletal muscle myogenesis is a multifactorial process of tissue growth and repair in response to resistance training is regulated by many factors.  As a result, satellite cell-fused myogenesis is a possible factor in skeletal muscle regeneration and hypertrophy in response to RT.  The Wnt family ligands interact with various receptors and activate different downstream signaling pathways and have been classified as either canonical (β-catenin dependent or non-canonical (β-catenin independent.  Wnt is secreted from numerous tissues in a paracrine fashion. The Wnt/β-catenin signaling pathway is a highly-regulated and intricate pathway that is essential to skeletal muscle myogenesis.  The canonical Wnt/β-catenin pathway may influence satellite cells to myogenic commitment, differentiation, and fusion into muscle fibers in response to injury or trauma, self-renewal, and normal basal turnover.  The current literature has shown that, in response mechanical overload from acute resistance exercise and chronic resistance training, that the Wnt/β-catenin signaling pathway is stimulated which may actuate the process of muscle repair and hypertrophy in response to exercise-induced muscle damage. The purpose of this review is to elaborate on the Wnt/β-catenin signaling  pathway, the current literature investigating the relationship of the Wnt/β-catenin pathway and its effects on myogenesis is response to muscle damage and resistance exercise and training.      Keywords: skeletal muscle, hypertrophy, myogenesis, cell signaling, protein synthesis, resistance

  10. (Pro)renin Receptor Is an Amplifier of Wnt/β-Catenin Signaling in Kidney Injury and Fibrosis.

    Science.gov (United States)

    Li, Zhen; Zhou, Lili; Wang, Yongping; Miao, Jinhua; Hong, Xue; Hou, Fan Fan; Liu, Youhua

    2017-08-01

    The (pro)renin receptor (PRR) is a transmembrane protein with multiple functions. However, its regulation and role in the pathogenesis of CKD remain poorly defined. Here, we report that PRR is a downstream target and an essential component of Wnt/ β -catenin signaling. In mouse models, induction of CKD by ischemia-reperfusion injury (IRI), adriamycin, or angiotensin II infusion upregulated PRR expression in kidney tubular epithelium. Immunohistochemical staining of kidney biopsy specimens also revealed induction of renal PRR in human CKD. Overexpression of either Wnt1 or β -catenin induced PRR mRNA and protein expression in vitro Notably, forced expression of PRR potentiated Wnt1-mediated β -catenin activation and augmented the expression of downstream targets such as fibronectin, plasminogen activator inhibitor 1, and α -smooth muscle actin ( α -SMA). Conversely, knockdown of PRR by siRNA abolished β -catenin activation. PRR potentiation of Wnt/ β -catenin signaling did not require renin, but required vacuolar H + ATPase activity. In the mouse model of IRI, transfection with PRR or Wnt1 expression vectors promoted β -catenin activation, aggravated kidney dysfunction, and worsened renal inflammation and fibrotic lesions. Coexpression of PRR and Wnt1 had a synergistic effect. In contrast, knockdown of PRR expression ameliorated kidney injury and fibrosis after IRI. These results indicate that PRR is both a downstream target and a crucial element in Wnt signal transmission. We conclude that PRR can promote kidney injury and fibrosis by amplifying Wnt/ β -catenin signaling. Copyright © 2017 by the American Society of Nephrology.

  11. Bauhinia championi (Benth.) Benth. polysaccharides upregulate Wnt/β-catenin signaling in chondrocytes.

    Science.gov (United States)

    Li, Huiting; Li, Xihai; Liu, Guozhong; Chen, Jiashou; Weng, Xiaping; Liu, Fayuan; Xu, Huifeng; Liu, Xianxiang; Ye, Hongzhi

    2013-12-01

    Bauhinia championi (Benth.) Benth. polysaccharides (BCBPs), extracted from Bauhinia championi (Benth.) Benth., which has been used in traditional Chinese medicine (TCM) for the treatment of osteoarthritis (OA), are the bioactive constituents of Bauhinia championi (Benth.) rattan. However, the molecular mechanisms responsible for their effects on OA are poorly understood. The Wnt/β-catenin signaling pathway plays an important role in the proliferation of chondrocytes. In the present study, the effects of BCBPs on Wnt/β-catenin signaling in chondrocytes were investigated. BCBPs were obtained by hot-water extraction and identified by the modified high performance liquid chromatography (HPLC) method. Chondrocytes were isolated from the knees of Sprague‑Dawley rats and identified by type II collagen immunohistochemistry. The chondrocytes were treated with or without BCBPs for 48 h. Cell viability was evaluated by MTT assay. The mRNA and protein levels of Wnt-4, β-catenin, Frizzled-2, glycogen synthase kinase (GSK)-3β, cyclin D1 and collagen II were detected by western blot analysis and reverse transcription PCR (RT-PCR), respectively. We found that the BCBPs contained at least seven monosaccharides, including D-mannose, rhamnose, D-(+) glucuronic acid, D-(+) galacturonic acid, D-glucose, galactose and arabinose. The cell viability of the chondrocytes treated with 50, 100 and 200 µg/ml BCBPs was significantly higher than that of the chondroctyes in the control group (treated with 0 µg/ml BCBPs). Furthermore, compared with the control group, the mRNA and protein expression of Wnt-4, β-catenin, Frizzled-2 and cyclin D1 in the BCBP-treated groups markedly increased, whereas the mRNA and protein expression of GSK-3β significantly decreased. Of note, the dose of 100 µg/ml BCBPs was more effective than the dose of 50 µg/ml BCBPs and 200 µg/ml BCBPs. In addition, we found that treatment with BCBPs upregulated the protein levels of collagen II in the

  12. 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

  13. Mice lacking liver-specific β-catenin develop steatohepatitis and fibrosis after iron overload.

    Science.gov (United States)

    Preziosi, Morgan E; Singh, Sucha; Valore, Erika V; Jung, Grace; Popovic, Branimir; Poddar, Minakshi; Nagarajan, Shanmugam; Ganz, Tomas; Monga, Satdarshan P

    2017-08-01

    Iron overload disorders such as hereditary hemochromatosis and iron loading anemias are a common cause of morbidity from liver diseases and increase risk of hepatic fibrosis and hepatocellular carcinoma (HCC). Treatment options for iron-induced damage are limited, partly because there is lack of animal models of human disease. Therefore, we investigated the effect of iron overload in liver-specific β-catenin knockout mice (KO), which are susceptible to injury, fibrosis and tumorigenesis following chemical carcinogen exposure. Iron overload diet was administered to KO and littermate control (CON) mice for various times. To ameliorate an oxidant-mediated component of tissue injury, N-Acetyl-L-(+)-cysteine (NAC) was added to drinking water of mice on iron overload diet. KO on iron diet (KO +Fe) exhibited remarkable inflammation, followed by steatosis, oxidative stress, fibrosis, regenerating nodules and occurrence of occasional HCC. Increased injury in KO +Fe was associated with activated protein kinase B (AKT), ERK, and NF-κB, along with reappearance of β-catenin and target gene Cyp2e1, which promoted lipid peroxidation and hepatic damage. Addition of NAC to drinking water protected KO +Fe from hepatic steatosis, injury and fibrosis, and prevented activation of AKT, ERK, NF-κB and reappearance of β-catenin. The absence of hepatic β-catenin predisposes mice to hepatic injury and fibrosis following iron overload, which was reminiscent of hemochromatosis and associated with enhanced steatohepatitis and fibrosis. Disease progression was notably alleviated by antioxidant therapy, which supports its chemopreventive role in the management of chronic iron overload disorders. Lack of animal models for iron overload disorders makes it hard to study the disease process for improving therapies. Feeding high iron diet to mice that lack the β-catenin gene in liver cells led to increased inflammation followed by fat accumulation, cell death and wound healing that mimicked

  14. Cadherin 2/4 signaling via PTP1B and catenins is crucial for nucleokinesis during radial neuronal migration in the neocortex.

    Science.gov (United States)

    Martinez-Garay, Isabel; Gil-Sanz, Cristina; Franco, Santos J; Espinosa, Ana; Molnár, Zoltán; Mueller, Ulrich

    2016-06-15

    Cadherins are crucial for the radial migration of excitatory projection neurons into the developing neocortical wall. However, the specific cadherins and the signaling pathways that regulate radial migration are not well understood. Here, we show that cadherin 2 (CDH2) and CDH4 cooperate to regulate radial migration in mouse brain via the protein tyrosine phosphatase 1B (PTP1B) and α- and β-catenins. Surprisingly, perturbation of cadherin-mediated signaling does not affect the formation and extension of leading processes of migrating neocortical neurons. Instead, movement of the cell body and nucleus (nucleokinesis) is disrupted. This defect is partially rescued by overexpression of LIS1, a microtubule-associated protein that has previously been shown to regulate nucleokinesis. Taken together, our findings indicate that cadherin-mediated signaling to the cytoskeleton is crucial for nucleokinesis of neocortical projection neurons during their radial migration. © 2016. Published by The Company of Biologists Ltd.

  15. Hypoxia-inducible factor-1α and Wnt/β-catenin signaling pathways promote the invasion of hypoxic gastric cancer cells.

    Science.gov (United States)

    Liu, Hong-Lan; Liu, Dang; Ding, Guang-Rong; Liao, Peng-Fei; Zhang, Jun-Wen

    2015-09-01

    The present study aimed to examine the association between hypoxia-inducible factor (HIF)-1α and the Wnt/β-catenin signaling pathway in a hypoxic environment. The study also aimed to explore the possible mechanisms underlying the invasion of hypoxic gastric cancer cells in vitro and in vivo. The pcDNA™ 6.2‑GW/EmGFP‑miR‑β‑catenin plasmid was transfected into SGC‑7901 gastric cancer cells, resulting in cells with stable suppression of β‑catenin expression. The biological characteristics of the control, liposome, negative control, β‑catenin knockdown, hypoxia and hypoxia β‑catenin knockdown groups were tested using an invasion assay. The differences in the invasive capacity of the control, negative control and liposome groups were not statistically significant. However, the hypoxia group demonstrated a significantly enhanced invasive capacity, as compared with that in the control group (Phypoxic and control cells was high alongside increased HIF‑1α, β‑catenin, uPA and MMP‑7 levels according to western blot and immunohistochemical analyses, while growth and protein levels of tumors from hypoxic β‑catenin knockdown cells were significantly lower and those of β‑catenin knockdown cells were lowest. In conclusion, these results suggested that HIF‑1α activation was able to regulate the Wnt/β‑catenin pathway, and that HIF‑1α may be controlled by the Wnt/β‑catenin pathway. A potential mechanism underlying SGC‑7901 tumorigenicity is the activation of the Wnt/β‑catenin signaling pathway, which activates uPA and MMP‑7 expression and contributes to the enhanced invasion of hypoxic cancer cells.

  16. Association of differential β-catenin expression with Oct-4 and Nanog in oral squamous cell carcinoma and their correlation with clinicopathological factors and prognosis.

    Science.gov (United States)

    Ravindran, Gokulan; Sawant, Sharada S; Hague, Angela; Kingsley, Karl; Devaraj, Halagowder

    2015-07-01

    The re-expression of pluripotent markers (Oct-4 and Nanog) and the reactivation of stem cell-related pathways in oral carcinoma have been well researched. However, the relationship between the stem cell signaling molecule β-catenin and pluripotent markers Oct-4 and Nanog in oral cancer is yet to be studied in detail. Therefore, we have investigated the correlation among Oct-4, Nanog, and β-catenin in oral squamous cell carcinoma, which, in turn, could provide valuable insight into its prognostic significance. The immunohistochemical analysis was performed for 60 cases of oral cancer to study the expression pattern of Oct-4, Nanog, and β-catenin. Whereas immunofluorescence analysis was used to investigate the co-localization of β-catenin with Oct-4 and Nanog in oral carcinoma tissues and H314 cell line. Finally, co-immunoprecipitation analysis was used to study the possible interaction between β-catenin and Oct-4 in oral carcinoma cells. β-catenin, Oct-4, and Nanog showed significant correlation with lymph node metastasis, stage, grade, and prognosis in oral squamous cell carcinoma. Interestingly, a significant positive correlation was found among the expression of Oct-4, Nanog, and β-catenin. Moreover, the interaction between β-catenin and Oct-4 was observed in oral cancer. The positive correlation among Oct-4, Nanog, and β-catenin suggests their coordinated role in maintaining proliferation in oral carcinoma cells. The interaction between β-catenin and Oct-4 may be a crucial event in oral carcinogenesis. On the other hand, β-catenin, Oct-4, and Nanog could be used as independent prognostic markers of oral squamous cell carcinoma. © 2014 Wiley Periodicals, Inc.

  17. 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.

  18. Correlation of β-Catenin Localization with Cyclooxygenase-2 Expression and CpG Island Methylator Phenotype (CIMP in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Takako Kawasaki

    2007-07-01

    Full Text Available The WNT/β-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 (3-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 (β-catenin activation and CIMP status. Using 832 population-based colorectal cancer specimens, we assessed (3-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 (β-catenin expressions (i.e., β-catenin activation and associated positively with membrane expression. The inverse relation between (β-catenin activation and CIMP was independent of MSI. COX-2 overexpression correlated with cytoplasmic (β-catenin expression (even after tumors were stratified by CIMP status, but did not correlate significantly with nuclear or membrane expression. In conclusion, β-catenin activation is inversely associated with CIMP-high independent of MSI status. Cytoplasmic β-catenin is associated with COX-2 overexpression, supporting the role of cytoplasmic β-catenin in stabilizing PTGS2(COX-2 mRNA.

  19. Wnt signaling positively regulates endothelial cell fate specification in the Fli1a-positive progenitor population via Lef1.

    Science.gov (United States)

    Hübner, Kathleen; Grassme, Kathrin S; Rao, Jyoti; Wenke, Nina K; Zimmer, Cordula L; Korte, Laura; Mu Ller, Katja; Sumanas, Saulius; Greber, Boris; Herzog, Wiebke

    2017-10-01

    During vertebrate embryogenesis, vascular endothelial cells (ECs) and primitive erythrocytes become specified within close proximity in the posterior lateral plate mesoderm (LPM) from a common progenitor. However, the signaling cascades regulating the specification into either lineage remain largely elusive. Here, we analyze the contribution of β-catenin dependent Wnt signaling to EC and erythrocyte specification during zebrafish embryogenesis. We generated novel β-catenin dependent Wnt signaling reporters which, by using destabilized fluorophores (Venus-Pest, dGFP), specifically allow us to detect Wnt signaling responses in narrow time windows as well as in spatially restricted domains, defined by Cre recombinase expression (Tg(axin2 BAC :Venus-Pest) mu288 ; Tg(14TCF:loxP-STOP-loxP-dGFP) mu202 ). We therefore can detect β-catenin dependent Wnt signaling activity in a subset of the Fli1a-positive progenitor population. Additionally, we show that mesodermal Wnt3a-mediated signaling via the transcription factor Lef1 positively regulates EC specification (defined by kdrl expression) at the expense of primitive erythrocyte specification (defined by gata1 expression) in zebrafish embryos. Using mesoderm derived from human embryonic stem cells, we identified the same principle of Wnt signaling dependent EC specification in conjunction with auto-upregulation of LEF1. Our data indicate a novel role of β-catenin dependent Wnt signaling in regulating EC specification during vasculogenesis. Copyright © 2017. Published by Elsevier Inc.

  20. 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.

  1. 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.

  2. β-Catenin Is a Positive Regulator of Estrogen Receptor-α Function in Breast Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Nibedita; Schmitt, Fee; Grebhardt, Sina; Mayer, Doris, E-mail: d.mayer@dkfz.de [Hormones and Signal Transduction Group, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 581, 69120 Heidelberg (Germany)

    2011-07-22

    Estrogen receptor-alpha (ERα) is a key factor in the development of breast cancer in humans. The expression and activity of ERα is regulated by a multitude of intracellular and extracellular signals. Here we show a cross-talk between β-catenin and ERα in human breast cancer cells. Knockdown of β-catenin by RNAi resulted in significant reduction of ERα mRNA and/or protein levels in MCF-7, T-47D, and BT-474 breast cancer cells and in significant reduction of estradiol-induced expression of the ERα target genes pS2 and GREB1. In addition β-catenin silencing resulted in significant decrease of growth of MCF-7 cells both in the absence and presence of estradiol. β-catenin and ERα could not be co-immunoprecipitated by ERα antibodies from lysates of E2-treated or untreated cells suggesting lack of direct physical interaction. It is concluded that β-catenin is a positive regulator of ERα mRNA and protein expression.

  3. 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.

  4. Regulation of the Wnt/β-Catenin Signaling Pathway by Human Papillomavirus E6 and E7 Oncoproteins

    Directory of Open Access Journals (Sweden)

    Jesus Omar Muñoz Bello

    2015-08-01

    Full Text Available Cell signaling pathways are the mechanisms by which cells transduce external stimuli, which control the transcription of genes, to regulate diverse biological effects. In cancer, distinct signaling pathways, such as the Wnt/β-catenin pathway, have been implicated in the deregulation of critical molecular processes that affect cell proliferation and differentiation. For example, changes in β-catenin localization have been identified in Human Papillomavirus (HPV-related cancers as the lesion progresses. Specifically, β-catenin relocates from the membrane/cytoplasm to the nucleus, suggesting that this transcription regulator participates in cervical carcinogenesis. The E6 and E7 oncoproteins are responsible for the transforming activity of HPV, and some studies have implicated these viral oncoproteins in the regulation of the Wnt/β-catenin pathway. Nevertheless, new interactions of HPV oncoproteins with cellular proteins are emerging, and the study of the biological effects of such interactions will help to understand HPV-related carcinogenesis. Viruses 2015, 7 4735 This review addresses the accumulated evidence of the involvement of the HPV E6 and E7 oncoproteins in the activation of the Wnt/β-catenin pathway.

  5. 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

  6. Distinct Roles of Wnt/β-Catenin Signaling in the Pathogenesis of Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis

    Science.gov (United States)

    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

  7. Endothelial β-Catenin Signaling Is Required for Maintaining Adult Blood-Brain Barrier Integrity and Central Nervous System Homeostasis.

    Science.gov (United States)

    Tran, Khiem A; Zhang, Xianming; Predescu, Dan; Huang, Xiaojia; Machado, Roberto F; Göthert, Joachim R; Malik, Asrar B; Valyi-Nagy, Tibor; Zhao, You-Yang

    2016-01-12

    The blood-brain barrier (BBB) formed by brain endothelial cells interconnected by tight junctions is essential for the homeostasis of the central nervous system. Although studies have shown the importance of various signaling molecules in BBB formation during development, little is known about the molecular basis regulating the integrity of the adult BBB. Using a mouse model with tamoxifen-inducible endothelial cell-restricted disruption of ctnnb1 (iCKO), we show here that endothelial β-catenin signaling is essential for maintaining BBB integrity and central nervous system homeostasis in adult mice. The iCKO mice developed severe seizures accompanied by neuronal injury, multiple brain petechial hemorrhages, and central nervous system inflammation, and all had postictal death. Disruption of endothelial β-catenin induced BBB breakdown and downregulation of the specific tight junction proteins claudin-1 and -3 in adult brain endothelial cells. The clinical relevance of the data is indicated by the observation of decreased expression of claudin-1 and nuclear β-catenin in brain endothelial cells of hemorrhagic lesions of hemorrhagic stroke patients. These results demonstrate the prerequisite role of endothelial β-catenin in maintaining the integrity of adult BBB. The results suggest that BBB dysfunction secondary to defective β-catenin transcription activity is a key pathogenic factor in hemorrhagic stroke, seizure activity, and central nervous system inflammation. © 2015 American Heart Association, Inc.

  8. 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.

  9. Activation of the Canonical Wnt/β-Catenin Signalling Pathway is Rare in Canine Malignant Melanoma Tissue and Cell Lines

    Science.gov (United States)

    Chon, E.; Thompson, V.; Schmid, S.; Stein, T. J.

    2012-01-01

    Summary Canine malignant melanoma is a highly aggressive tumour associated with a poor overall survival rate due to both local disease recurrence and its highly metastatic nature. Similar to advanced melanoma in man, canine oral melanoma is poorly responsive to conventional anti-cancer therapies. The lack of sustainable disease control warrants investigation of novel therapies, preferably targeting features specific to the tumour and different from normal cells. The Wnt signalling pathway is known to contribute to melanocytic lineage development in vertebrates and perturbation of the Wnt/β-catenin pathway has been implicated in numerous cancer types. Alterations of the Wnt/β-catenin pathway are suggested to occur in a subset of human melanomas, although the precise role of the Wnt/β-catenin pathway in melanoma is yet to be defined. This study investigates the activation status of the canonical Wnt/β-catenin pathway in canine malignant melanoma and its potential as a therapeutic target for treating this disease. The data indicate canonical Wnt/β-catenin pathway activation is a rare event in canine oral malignant melanoma tissue and canine malignant melanoma cell lines. PMID:22901430

  10. R-spondin 3 regulates dorsoventral and anteroposterior patterning by antagonizing Wnt/β-catenin signaling in zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Xiaozhi Rong

    Full Text Available The Wnt/β-catenin or canonical Wnt signaling pathway plays fundamental roles in early development and in maintaining adult tissue homeostasis. R-spondin 3 (Rspo3 is a secreted protein that has been implicated in activating the Wnt/β-catenin signaling in amphibians and mammals. Here we report that zebrafish Rspo3 plays a negative role in regulating the zygotic Wnt/β-catenin signaling. Zebrafish Rspo3 has a unique domain structure. It contains a third furin-like (FU3 domain. This FU3 is present in other four ray-finned fish species studied but not in elephant shark. In zebrafish, rspo3 mRNA is maternally deposited and has a ubiquitous expression in early embryonic stages. After 12 hpf, its expression becomes tissue-specific. Forced expression of rspo3 promotes dorsoanterior patterning and increases the expression of dorsal and anterior marker genes. Knockdown of rspo3 increases ventral-posterior development and stimulates ventral and posterior marker genes expression. Forced expression of rspo3 abolishes exogenous Wnt3a action and reduces the endogenous Wnt signaling activity. Knockdown of rspo3 results in increased Wnt/β-catenin signaling activity. Further analyses indicate that Rspo3 does not promote maternal Wnt signaling. Human RSPO3 has similar action when tested in zebrafish embryos. These results suggest that Rspo3 regulates dorsoventral and anteroposterior patterning by negatively regulating the zygotic Wnt/β-catenin signaling in zebrafish embryos.

  11. 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.

  12. 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.

  13. 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.

  14. Wnt/β-Catenin Signaling Regulates the Expression of the Ammonium Permease Gene RHBG in Human Cancer Cells.

    Directory of Open Access Journals (Sweden)

    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.

  15. Activation of Wnt/β-catenin signaling is involved in hair growth-promoting effect of 655-nm red light and LED in in vitro culture model.

    Science.gov (United States)

    Han, Le; Liu, Ben; Chen, Xianyan; Chen, Haiyan; Deng, Wenjia; Yang, Changsheng; Ji, Bin; Wan, Miaojian

    2018-04-01

    Activation of the Wnt/β-catenin signaling pathway plays an important role in hair follicle morphogenesis and hair growth. Recently, low-level laser therapy (LLLT) was evaluated for stimulating hair growth in numerous clinical studies, in which 655-nm red light was found to be most effective and practical for stimulating hair growth. We evaluated whether 655-nm red light + light-emitting diode (LED) could promote human hair growth by activating Wnt/β-catenin signaling. An in vitro culture of human hair follicles (HFs) was irradiated with different intensities of 655-nm red light + LED, 21 h7 (an inhibitor of β-catenin), or both. Immunofluorescence staining was performed to assess the expression of β-catenin, GSK3β, p-GSK3β, and Lef1 in the Wnt/β-catenin signaling. The 655-nm red light + LED not only enhanced hair shaft elongation, but also reduced catagen transition in human hair follicle organ culture, with the greatest effectiveness observed at 5 min (0.839 J/cm 2 ). Additionally, 655-nm red light + LED enhanced the expression of β-catenin, p-GSK3β, and Lef1, signaling molecules of the Wnt/β-catenin pathway, in the hair matrix. Activation of Wnt/β-catenin signaling is involved in hair growth-promoting effect of 655-nm red light and LED in vitro and therefore may serve as an alternative therapeutic option for alopecia.

  16. 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,

  17. 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...

  18. Reversible Modification of Adenomatous Polyposis Coli (APC) with K63-linked Polyubiquitin Regulates the Assembly and Activity of the β-Catenin Destruction Complex

    Science.gov (United States)

    Tran, Hoanh; Polakis, Paul

    2012-01-01

    The adenomatous polyposis coli (APC) tumor suppressor forms a complex with Axin and GSK3β to promote the phosphorylation and degradation of β-catenin, a key co-activator of Wnt-induced transcription. Here, we establish that APC is modified predominantly with K63-linked ubiquitin chains when it is bound to Axin in unstimulated HEK293 cells. Wnt3a stimulation induced a time-dependent loss of K63-polyubiquitin adducts from APC, an effect synchronous with the dissociation of Axin from APC and the stabilization of cytosolic β-catenin. RNAi-mediated depletion of Axin or β-catenin, which negated the association between APC and Axin, resulted in the absence of K63-adducts on APC. Overexpression of wild-type and phosphodegron-mutant β-catenin, combined with analysis of thirteen human cancer cell lines that harbor oncogenic mutations in APC, Axin, or β-catenin, support the hypothesis that a fully assembled APC-Axin-GSK3β-phospho-β-catenin complex is necessary for the K63-polyubiquitylation of APC. Intriguingly, the degree of this modification on APC appears to correlate inversely with the levels of β-catenin in cells. Together, our results indicate that K63-linked polyubiquitin adducts on APC regulate the assembly and/or efficiency of the β-catenin destruction complex. PMID:22761442

  19. Altered Wnt Signaling Pathway in Cognitive Impairment Caused by Chronic Intermittent Hypoxia: Focus on Glycogen Synthase Kinase-3β and β-catenin

    Directory of Open Access Journals (Sweden)

    Yue-Ying Pan

    2016-01-01

    Conclusions: Wnt/β-catenin signaling pathway abnormalities possibly play an important role in the development of cognitive deficits among mice exposed to CIH and that LiCl might attenuate CIH-induced cognitive impairment via Wnt/β-catenin signaling pathway.

  20. Activation status of Wnt/ß-catenin signaling in normal and neoplastic breast tissues: relationship to HER2/neu expression in human and mouse.

    Directory of Open Access Journals (Sweden)

    Sara Khalil

    Full Text Available Wnt/ß-catenin signaling is strongly implicated in neoplasia, but the role of this pathway in human breast cancer has been controversial. Here, we examined Wnt/ß-catenin pathway activation as a function of breast cancer progression, and tested for a relationship with HER2/neu expression, using a human tissue microarray comprising benign breast tissues, ductal carcinoma in situ (DCIS, and invasive carcinomas. Cores were scored for membranous ß-catenin, a key functional component of adherens junctions, and for nucleocytoplasmic ß-catenin, a hallmark of Wnt/ß-catenin pathway activation. Only 82% of benign samples exhibited membrane-associated ß-catenin, indicating a finite frequency of false-negative staining. The frequency of membrane positivity was similar in DCIS samples, but was significantly reduced in carcinomas (45%, P<0.001, consistent with loss of adherens junctions during acquisition of invasiveness. Negative membrane status in cancers correlated with higher grade (P = 0.04 and estrogen receptor-negative status (P = 0.03, both indices of poor prognosis. Unexpectedly, a substantial frequency of nucleocytoplasmic ß-catenin was observed in benign breast tissues (36%, similar to that in carcinomas (35%. Positive-staining basal nuclei observed in benign breast may identify putative stem cells. An increased frequency of nucleocytoplasmic ß-catenin was observed in DCIS tumors (56%, suggesting that pathway activation may be an early event in human breast neoplasia. A correlation was observed between HER2/neu expression and nucleocytoplasmic ß-catenin in node-positive carcinomas (P = 0.02. Furthermore, cytoplasmic ß-catenin was detected in HER2/neu-induced mouse mammary tumors. The Axin2(NLSlacZ mouse strain, a previously validated reporter of mammary Wnt/ß-catenin signaling, was utilized to define in vivo transcriptional consequences of HER2/neu-induced ß-catenin accumulation. Discrete hyperplastic foci observed in mammary

  1. A Complex Interplay between Wnt/β-Catenin Signalling and the Cell Cycle in the Adult Liver

    Directory of Open Access Journals (Sweden)

    Angélique Gougelet

    2012-01-01

    Full Text Available Canonical Wnt signalling, governed by its effector β-catenin, is known for a long time as playing an important role in development, tissue homeostasis, and cancer. In the liver, it was unravelled as both an oncogenic pathway involved in a subset of liver cancers and a physiological signalling identified as the “zonation-keeper” of the quiescent liver lobule. This duality has encouraged to explore the role of canonical Wnt in liver regeneration and liver-cell proliferation mainly using murine genetic models of β-catenin overactivation or inactivation. These studies definitely integrate Wnt signalling within the hepatic network driving regeneration and proliferation. We will review here the current knowledge concerning the mitogenic effect of Wnt, to switch on its specific role in the liver, which is quiescent but with a great capacity to regenerate. The duality of β-catenin signalling, associated both with liver quiescence and liver-cell proliferation, will be brought forward.

  2. A Complex Interplay between Wnt/β-Catenin Signalling and the Cell Cycle in the Adult Liver.

    Science.gov (United States)

    Gougelet, Angélique; Colnot, Sabine

    2012-01-01

    Canonical Wnt signalling, governed by its effector β-catenin, is known for a long time as playing an important role in development, tissue homeostasis, and cancer. In the liver, it was unravelled as both an oncogenic pathway involved in a subset of liver cancers and a physiological signalling identified as the "zonation-keeper" of the quiescent liver lobule. This duality has encouraged to explore the role of canonical Wnt in liver regeneration and liver-cell proliferation mainly using murine genetic models of β-catenin overactivation or inactivation. These studies definitely integrate Wnt signalling within the hepatic network driving regeneration and proliferation. We will review here the current knowledge concerning the mitogenic effect of Wnt, to switch on its specific role in the liver, which is quiescent but with a great capacity to regenerate. The duality of β-catenin signalling, associated both with liver quiescence and liver-cell proliferation, will be brought forward.

  3. Frontline Science: Wnt/β-catenin pathway promotes early engraftment of fetal hematopoietic stem/progenitor cells.

    Science.gov (United States)

    Kwarteng, Edward O; Hétu-Arbour, Roxann; Heinonen, Krista M

    2018-03-01

    The switch from fetal to adult hematopoietic stem/progenitor cells (HSPCs) is associated with profound changes in several genetic programs. Although HSPC ageing corresponds to alterations in Wnt signaling, relatively little is known about the relative roles of different Wnt signaling pathways in HSPC ontogeny. We hypothesized that proliferating fetal HSPCs would be more dependent on canonical β-catenin-dependent Wnt signaling when compared to quiescent adult bone marrow HSPCs. We have compared here Wnt signaling activities in murine fetal and adult HSPCs and demonstrate a shift from Wnt/β-catenin-dependent signaling in fetal liver HSPCs to more predominantly noncanonical Wnt/polarity signaling in adult HSPCs. β-Catenin was selectively required for fetal HSPC competitiveness shortly after transplant, and protected cells from oxidative stress. Our results emphasize the complexity of Wnt signaling dynamics in HSPC maintenance and function. ©2018 Society for Leukocyte Biology.

  4. Fibulin-4 is a novel Wnt/β-Catenin pathway activator in human osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Li, Renzeng [Department of Othopedics, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Road, Zhengzhou, 450000 Henan (China); Department of Orthopaedics, The No.3 People’s Hospital of Anyang City, Anyang 455000 (China); Wang, Limin, E-mail: gu2keo@163.com [Department of Othopedics, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Road, Zhengzhou, 450000 Henan (China)

    2016-06-10

    Fibulin-4, an extracellular glycoprotein implicated in connective tissue development and elastic fiber formation, draws increasing focuses in cancer research. However, little is known about the underlying oncogenic roles of Fibulin-4 in human osteosarcoma (OS). In this study, by immunohistochemical analysis, upregulated expression of Fibulin-4 was found in the OS clinical specimens and cell lines compared to their normal counterparts. Fibulin-4 was positively correlated with the T stage of OS patients, and the proliferation index Ki67. Based on informatics analysis and functional verification, microRNA-137 was identified as a potential upstream regulator of Fibulin-4. Knockdown of Fibulin-4 or introduction of microRNA-137 inhibited cell proliferation and promoted cell apoptosis, and adverse effects were observed by overexpression of Fibulin-4. Furthermore, the tumor-suppressive functions of microRNA-137 were markedly abolished by restoration of Fibulin-4 expression in OS cells. Mechanistically, Fibulin-4 activated Wnt/β-Catenin pathway and promoted the expression of its downstream targets, including CCND2, c-Myc and VEGF. Taken together, Fibulin-4 plays critical neoplastic roles in tumor growth of human OS by activating Wnt/β-Catenin signaling and may represent a potential therapeutic target. -- Highlights: •Upregulated Fibulin-4 correlates tumor growth in human OS. •MicroRNA-137 is a critical regulator of Fibulin-4 expression. •Deregulated miR-137/Fibulin-4 axis promotes tumor growth of human OS. •Wnt/β-Catenin pathway is activated by Fibulin-4 stimulation.

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

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    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.

  6. 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

  7. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ke-feng [Guangdong Key Laboratory for Research and Development of Natural Drugs, Guangdong Medical University, Zhanjiang, Guangdong (China); Liang, Wei-Cheng [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Feng, Lu [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Pang, Jian-xin [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China); Waye, Mary Miu-Yee [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Jin-Fang [Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong (China); Fu, Wei-Ming, E-mail: fuweiming76@smu.edu.cn [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515 (China)

    2017-01-15

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/β-catenin pathway

    International Nuclear Information System (INIS)

    Wu, Ke-feng; Liang, Wei-Cheng; Feng, Lu; Pang, Jian-xin; Waye, Mary Miu-Yee; Zhang, Jin-Fang; Fu, Wei-Ming

    2017-01-01

    Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/β-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/β-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC. - Highlights: • A methotrexate (MTX) -resistant colorectal cancer cell line HT-29 (HT-29-R) has been developed. • H19 was upregulated in HT-29-R cells. • H19 mediated MTX resistance in colorectal cancer (CRC). • Wnt/β-catenin pathway was involved in the H19-mediated MTX resistance in CRC cells.

  10. β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    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

  11. Fibulin-4 is a novel Wnt/β-Catenin pathway activator in human osteosarcoma

    International Nuclear Information System (INIS)

    Li, Renzeng; Wang, Limin

    2016-01-01

    Fibulin-4, an extracellular glycoprotein implicated in connective tissue development and elastic fiber formation, draws increasing focuses in cancer research. However, little is known about the underlying oncogenic roles of Fibulin-4 in human osteosarcoma (OS). In this study, by immunohistochemical analysis, upregulated expression of Fibulin-4 was found in the OS clinical specimens and cell lines compared to their normal counterparts. Fibulin-4 was positively correlated with the T stage of OS patients, and the proliferation index Ki67. Based on informatics analysis and functional verification, microRNA-137 was identified as a potential upstream regulator of Fibulin-4. Knockdown of Fibulin-4 or introduction of microRNA-137 inhibited cell proliferation and promoted cell apoptosis, and adverse effects were observed by overexpression of Fibulin-4. Furthermore, the tumor-suppressive functions of microRNA-137 were markedly abolished by restoration of Fibulin-4 expression in OS cells. Mechanistically, Fibulin-4 activated Wnt/β-Catenin pathway and promoted the expression of its downstream targets, including CCND2, c-Myc and VEGF. Taken together, Fibulin-4 plays critical neoplastic roles in tumor growth of human OS by activating Wnt/β-Catenin signaling and may represent a potential therapeutic target. -- Highlights: •Upregulated Fibulin-4 correlates tumor growth in human OS. •MicroRNA-137 is a critical regulator of Fibulin-4 expression. •Deregulated miR-137/Fibulin-4 axis promotes tumor growth of human OS. •Wnt/β-Catenin pathway is activated by Fibulin-4 stimulation.

  12. Methylprednisolone promotes recovery of neurological function after spinal cord injury: association with Wnt/β-catenin signaling pathway activation

    Science.gov (United States)

    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

  13. Hair growth-promoting effect of Aconiti Ciliare Tuber extract mediated by the activation of Wnt/β-catenin signaling.

    Science.gov (United States)

    Park, Phil-June; Moon, Byoung-San; Lee, Soung-Hoon; Kim, Su-Na; Kim, Ah-Reum; Kim, Hyung-Jun; Park, Won-Seok; Choi, Kang-Yell; Cho, Eun-Gyung; Lee, Tae Ryong

    2012-11-02

    The activation of Wnt/β-catenin signaling pathway plays an important role in hair follicle morphogenesis by stimulating bulge stem cells. This study was to obtain the activator of Wnt/β-catenin signaling pathway from natural products and to determine whether this activator can induce anagen hair growth in mice. To identify materials that activate Wnt/β-catenin signaling pathway, 800 natural product extracts were screened using pTOPFlash assay and neural progenitor cell (NPC) differentiation assay. A selected extract was further tested for its effects on alkaline phosphatase (ALP) activity in human immortalized dermal papilla cell (iDPC) and the proliferation in iDPC and immortalized rat vibrissa DPC (RvDP). Finally, hair growth-promoting effects were evaluated in the dorsal skin of C57BL/6 mice. Aconiti Ciliare Tuber (ACT) extract was one of the most active materials in both pTOPFlash and NPC differentiation assays. It promoted the differentiation of NPC cells even under proliferation-stimulating conditions (basic fibroblast growth factor: bFGF). It also increased ALP activity and proliferation of iDPC in dose-dependent manners, and it stimulated the induction of the anagen hair growth in C57BL/6 mice. These results suggest that ACT extract activates the Wnt/β-catenin signaling pathway by enhancing β-catenin transcription and has the potential to promote the induction of hair growth via activation of the stem cell activity of the dermal papilla cells. This is the first report indicating benefits of ACT extract in hair loss prevention by triggering the activation of Wnt/β-catenin signaling pathway and induction of the anagen hair growth in mice. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Comparative immunohistochemical expression of β-catenin, EGFR, ErbB2, and p63 in adamantinomatous and papillary craniopharyngiomas

    International Nuclear Information System (INIS)

    Eshebaa, Gh.E.; Hassan, A.A.

    2015-01-01

    Craniopharyngiomas (CPs) are rare epithelial tumors located mainly in the sellar/parasellar region. CPs have been classified into histopathologically, genetically, clinically and prognostically two distinctive subtypes: adamantinomatous and papillary variants. Aim To determine the immunohistochemical expression of β-catenin, EGFR, ErbB2, and p63 in adamantinomatous and papillary CPs. Materials and methods β-Catenin, EGFR, ErbB2, and p63 immunostaining was performed on paraffin embedded tissue sections of 25 CPs including 18 adamantinomatous craniopharyngioma (ACP) and 7 cases of papillary craniopharyngiomas (PCPs). Results 17 cases (94%) of ACP exhibited strong nuclear/cytoplasmic expression of β-catenin. On the contrary, all cases of PCP showed exclusively membranous expression (ρ value <0.0001). Regarding EGFR, 15 (83%) and 5 cases (71%) of APC and PCP respectively were positive. On the other hand, only 3 cases (17%) of APC and none of PCP exhibited positivity for ErbB2. p63 over-expression was observed in 16 cases of ACP (89%) and 6 cases of PCP (86%). However, the distribution of p63 staining was diffuse in ACP, while in PCP; the staining was mainly restricted to the basal cell layer. Conclusion Nuclear accumulation of β-catenin is a diagnostic hallmark of the ACP and is very helpful in the differential diagnosis between both ACP and PCP in the setting of small biopsies. Moreover, the restricted nuclear β-catenin accumulation in the cohesive cell clusters within the whorl-like areas supports that aberrant β-catenin expression may play a role in the morphogenesis of ACP.

  15. The role of Wnt/β-catenin signaling in enterocyte turnover during methotrexate-induced intestinal mucositis in a rat.

    Directory of Open Access Journals (Sweden)

    Igor Sukhotnik

    Full Text Available BACKGROUND/AIMS: Intestinal mucositis is a common side-effect in patients who receive aggressive chemotherapy. The Wnt signaling pathway is critical for establishing and maintaining the proliferative compartment of the intestine. In the present study, we tested whether Wnt/β-catenin signaling is involved in methotrexate (MTX-induced intestinal damage in a rat model. METHODS: Non-pretreated and pretreated with MTX Caco-2 cells were evaluated for cell proliferation and apoptosis using FACS analysis. Adult rats were divided into three experimental groups: Control rats; MTX-2 animals were treated with a single dose of MTX given IP and were sacrificed on day 2, and MTX-4 rats were treated with MTX similar to group B and were sacrificed on day 4. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation, and enterocyte apoptosis were measured at sacrifice. Real Time PCR and Western blot was used to determine the level of Wnt/β-catenin related genes and protein expression. RESULTS: In the vitro experiment, treatment with MTX resulted in marked decrease in early cell proliferation rates following by a 17-fold increase in late cell proliferation rates compared to early proliferation. Treatment with MTX resulted in a significant increase in early and late apoptosis compared to Caco-2 untreated cells. In the vivo experiment, MTX-2 and MTX-4 rats demonstrated intestinal mucosal hypoplasia. MTX-2 rats demonstrated a significant decrease in FRZ-2, Wnt 3A Wnt 5A, β-catenin, c-myc mRNA expression and a significant decrease in β-catenin and Akt protein levels compared to control animals. Four days following MTX administration, rats demonstrated a trend toward a restoration of Wnt/β-catenin signaling especially in ileum. CONCLUSIONS: Wnt/β-catenin signaling is involved in enterocyte turnover during MTX-induced intestinal mucositis in a rat.

  16. MiR-200a is involved in rat epididymal development by targeting β-catenin mRNA

    Institute of Scientific and Technical Information of China (English)

    Xiaojiang Wu; Botao Zhao; Wei Li; Yue Chen; Ruqiang Liang; Lin Li; Youxin Jin; Kangcheng Ruan

    2012-01-01

    The expression of 350 microRNAs (miRNAs) in epididymis of rat from postnatal development to adult (from postnatal days 7-70) was profiled with home-made miRNA microarray.Among them,48 miRNAs changed significantly, in which the expression of miR-200a increased obviously with time,in a good agreement with that obtained from northern blot analysis.The real-time quantitative-polymerase chain reaction result indicated that temporal expression of rat β-catenin was exactly inversed to that of miR-200a during rat epididymal development,implying that miR-200a might also target β-catenin mRNA in rat epididymis as reported by Saydam et al.in humans.The bioinformatic analysis indicated that 3' untranslated region of rat β-catenin mRNA did contain a putative binding site for miR-200a.Meanwhile,it was found that the sequence of this binding site was different from that of human β-catenin mRNA with a deletion of two adjacent nucleotides (U and C).But the results of luciferase targeting assay in HEK 293T cells and the overexpression of miR-200a in rat NRK cells demonstrated that miR-200a did target rat β-catenin mRNA and cause the suppression of its expression.All these results show that miR-200a should be involved in rat epididymal development by targeting β-catenin mRNA of rat and suppressing its expression.

  17. HIV-1 protein induced modulation of primary human osteoblast differentiation and function via a Wnt/β-catenin-dependent mechanism.

    LENUS (Irish Health Repository)

    Butler, Joseph S

    2013-02-01

    HIV infection is associated with metabolic bone disease resulting in bone demineralization and reduced bone mass. The molecular mechanisms driving this disease process have yet to be elucidated. Wnt\\/β-catenin signaling plays a key role in bone development and remodeling. We attempted to determine the effects of the HIV-1 protein, gp120, on Wnt\\/β-catenin signaling at an intracellular and transcriptional level in primary human osteoblasts (HOBs). This work, inclusive of experimental controls, was part of a greater project assessing the effects of a variety of different agents on Wnt\\/β-catenin signaling (BMC Musculoskelet Disord 2010;11:210).We examined the phenotypic effects of silencing and overexpressing the Wnt antagonist, Dickkopf-1 (Dkk1) in HOBs treated with gp120. HOBs exposed to gp120 displayed a significant reduction in alkaline phosphatase activity (ALP) activity and cell proliferation and increased cellular apoptosis over a 48 h time course. Immunocytochemistry demonstrated a significant reduction in intracytosolic and intranuclear β-catenin in response to HIV-1 protein exposure. These changes were associated with a reduction of TCF\\/LEF-mediated transcription, the transcriptional outcome of canonical Wnt β-catenin signaling. Silencing Dkk1 expression in HOBs exposed to gp120 resulted in increased ALP activity and cell proliferation, and decreased cellular apoptosis relative to scrambled control. Dkk1 overexpression exacerbated the inhibitory effect of gp120 on HOB function, with decreases in ALP activity and cell proliferation and increased cellular apoptosis relative to vector control. Wnt\\/β-catenin signaling plays a key regulatory role in HIV-associated bone loss, with Dkk1, aputative central mediator in this degenerative process. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 218-226, 2013.

  18. Wnt/β-catenin signalling regulates Sox17 expression and is essential for organizer and endoderm formation in the mouse.

    Science.gov (United States)

    Engert, Silvia; Burtscher, Ingo; Liao, W Perry; Dulev, Stanimir; Schotta, Gunnar; Lickert, Heiko

    2013-08-01

    Several signalling cascades are implicated in the formation and patterning of the three principal germ layers, but their precise temporal-spatial mode of action in progenitor populations remains undefined. We have used conditional gene deletion of mouse β-catenin in Sox17-positive embryonic and extra-embryonic endoderm as well as vascular endothelial progenitors to address the function of canonical Wnt signalling in cell lineage formation and patterning. Conditional mutants fail to form anterior brain structures and exhibit posterior body axis truncations, whereas initial blood vessel formation appears normal. Tetraploid rescue experiments reveal that lack of β-catenin in the anterior visceral endoderm results in defects in head organizer formation. Sox17 lineage tracing in the definitive endoderm (DE) shows a cell-autonomous requirement for β-catenin in midgut and hindgut formation. Surprisingly, wild-type posterior visceral endoderm (PVE) in midgut- and hindgut-deficient tetraploid chimera rescues the posterior body axis truncation, indicating that the PVE is important for tail organizer formation. Upon loss of β-catenin in the visceral endoderm and DE lineages, but not in the vascular endothelial lineage, Sox17 expression is not maintained, suggesting downstream regulation by canonical Wnt signalling. Strikingly, Tcf4/β-catenin transactivation complexes accumulated on Sox17 cis-regulatory elements specifically upon endoderm induction in an embryonic stem cell differentiation system. Together, these results indicate that the Wnt/β-catenin signalling pathway regulates Sox17 expression for visceral endoderm pattering and DE formation and provide the first functional evidence that the PVE is necessary for gastrula organizer gene induction and posterior axis development.

  19. 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.

  20. A kinetic model to study the regulation of β-catenin, APC, and Axin in the human colonic crypt.

    Science.gov (United States)

    Emerick, Brooks; Schleiniger, Gilberto; Boman, Bruce M

    2017-11-01

    The Wnt/[Formula: see text]-catenin pathway plays a crucial role in stem cell renewal and differentiation in the normal human colonic crypt. The balance between [Formula: see text]-catenin and APC along the crypt axis determines its normal functionality. The mechanism that deregulates this balance may give insight into the initiation of colorectal cancer. This is significant because the spatial dysregulation of [Formula: see text]-catenin by the mutated tumor suppressor gene/protein APC in human colonic crypts is responsible for the initiation and growth of colorectal cancer. We consider a regulatory function that promotes APC synthesis within the cell and its effect on the accumulation of the Wnt target protein, [Formula: see text]-catenin. It is evident that an APC gradient exists along the crypt axis; however, the mechanism by which APC expression is regulated within the cell is not well known. We investigate the dynamics of an APC regulatory mechanism with an increased level of Axin at the subcellular level. Model output shows an increase of APC for a diminished Wnt signal, which explains the APC gradient along the crypt. We find that the dynamic interplay between [Formula: see text]-catenin, APC, and Axin produces oscillatory behavior, which is controlled by the Wnt stimulus. In the presence of reduced functional APC, the oscillations are amplified, which suggests that the cell remains in a more proliferative state for longer periods of time. Increased Axin levels (typical of mammalian cells) reduce oscillatory behavior and minimize the levels of [Formula: see text]-catenin within the cell while raising the levels of APC.

  1. TC-1 (c8orf4) enhances aggressive biologic behavior in lung cancer through the Wnt/β-catenin pathway.

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    Su, Kai; Huang, Lijun; Li, Wenhai; Yan, Xiaolong; Li, Xiaofei; Zhang, Zhipei; Jin, Faguang; Lei, Jie; Ba, Guangzhen; Liu, Boya; Wang, Xiaoping; Wang, Yunjie

    2013-11-01

    The thyroid cancer-1 (TC-1) or c8orf4 gene encodes a 106-residue naturally disordered protein that has been found to be associated with thyroid, gastric, and breast cancer. A recent study has indicated that the protein functions as a positive regulator in the Wnt/β-catenin signaling pathway in human breast cancer. However, no research has been done in the area of lung cancer. Therefore, the goal of the present study was to confirm the relationship among TC-1, lung cancer, and the Wnt/β-catenin signaling pathway. The expression of TC-1 was immunohistochemically examined in 147 patients with non-small-cell lung cancer. TC-1-overexpressed and silenced A549 cells were infected using lentivirus and MTT cell proliferation analysis, and Matrigel invasion assays and scratch-wound assays were performed to confirm the biologic behavioral changes in different A549 cell subsets. The Wnt/β-catenin signaling pathway, key gene β-catenin, target genes of vascular endothelial growth factor, cyclin D1, matrix metalloproteinase-7, c-myc, and survivin were tested at the mRNA and protein level. TC-1 was detected in 97 of the 147 non-small-cell lung cancer primary tumor specimens, and its expression correlated with the TNM stage and regional lymph node metastasis (P cell line. Furthermore, expression of TC-1 protein affected the Wnt/β-catenin signaling pathway's downstream genes, such as vascular endothelial growth factor and matrix metalloproteinase-7, at the mRNA and protein level. TC-1 expression is associated with aggressive biologic behavior in lung cancer and might coordinate with the Wnt/β-catenin pathway as a positive upstream regulator that induces these behaviors. Copyright © 2013 Elsevier Inc. All rights reserved.

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

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    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.

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

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    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.

  4. LGR5 is expressed by Ewing sarcoma and potentiates Wnt/β-catenin signaling

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    Christopher A Scannell

    2013-04-01

    Full Text Available Ewing sarcoma (ES is an aggressive bone and soft tissue tumor of putative stem cell origin that predominantly occurs in children and young adults. Although most patients with localized ES can be cured with intensive therapy, the clinical course is variable and up to one third of patients relapse following initial remission. Unfortunately, little is yet known about the biologic features that distinguish low-risk from high-risk disease or the mechanisms of ES disease progression. Recent reports have suggested that putative cancer stem cells exist in ES and may contribute to an aggressive phenotype. The cell surface receptor LGR5 (leucine-rich repeat-containing G-protein coupled receptor 5 is a somatic stem cell marker that functions as an oncogene in several human cancers, most notably colorectal carcinoma. LGR5 is a receptor for the R-spondin (RSPO family of ligands and RSPO-mediated activation of LGR5 potentiates Wnt/β-catenin signaling, contributing to stem cell proliferation and self-renewal. Given its presumed stem cell origin, we investigated whether LGR5 contributes to ES pathogenesis. We found that LGR5 is expressed by ES and that its expression is relatively increased in cells and tumors that display a more aggressive phenotype. In particular, LGR5 expression was increased in putative cancer stem cells. We also found that neural crest-derived stem cells express LGR5, raising the possibility that expression of LGR5 may be a feature of ES cells of origin. LGR5-high ES cells showed nuclear localization of ß-catenin and robust activation of TCF-reporter activity when exposed to Wnt ligand and this was potentiated by RSPO. However, modulation of LGR5 or exposure to RSPO had no impact on proliferation confirming that Wnt/ β-catenin signaling in ES cells does not recapitulate signaling in epithelial cells. Together these studies show that the RSPO-LGR5-WNT- β-catenin axis is present and active in ES and may contribute to tumor pathogenesis.

  5. L-carnitine contributes to enhancement of neurogenesis from mesenchymal stem cells through Wnt/β-catenin and PKA pathway.

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    Fathi, Ezzatollah; Farahzadi, Raheleh; Charoudeh, Hojjatollah Nozad

    2017-03-01

    The identification of factors capable of enhancing neurogenesis has great potential for cellular therapies in neurodegenerative diseases. Multiple studies have shown the neuroprotective effects of L-carnitine (LC). This study determined whether neuronal differentiation of rat adipose tissue-derived mesenchymal stem cells (ADSCs) can be activated by LC. In this study, protein kinase A (PKA) and Wnt/β-catenin pathways were detected to show if this activation was due to these pathways. The expression of LC-induced neurogenesis markers in ADSCs was characterized using real-time PCR. ELISA was conducted to assess the expression of cyclic adenosine monophosphate (cAMP) and PKA. The expression of β-catenin, reduced dickkopf1 (DKK1), low-density lipoprotein receptor-related protein 5 (LRP5), Wnt1, and Wnt3a genes as Wnt/β-catenin signaling members were used to detect the Wnt/β-catenin pathway. It was observed that LC could promote neurogenesis in ADSCs as well as expression of some neurogenic markers. Moreover, LC causes to increase the cAMP levels and PKA activity. Treatment of ADSCs with H-89 (dihydrochloride hydrate) as PKA inhibitor significantly inhibited the promotion of neurogenic markers, indicating that the PKA signaling pathway could be involved in neurogenesis induction. Analyses of real-time PCR data showed that the mRNA expressions of β-catenin, DKK1, LRP5c-myc, Wnt1, and Wnt3a were increased in the presence of LC. Therefore, the present study showed that LC promotes ADSCs neurogenesis and the LC-induced neurogenic markers could be due to both the PKA and Wnt/β-catenin signaling pathway. Impact statement Neural tissue has long been believed as incapable of regeneration and the identification of cell types and factors capable of neuronal differentiation has generated intense interest. Mesenchymal stem cells (MSCs) are considered as potential targets for stem cell-based therapy. L-carnitin (LC) as an antioxidant may have neuroprotective effects in

  6. 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

  7. [Effect of total glucosides of paeony on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats].

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    Chang, Bao-Chao; Chen, Wei-Dong; Zhang, Yan; Yang, Ping; Liu, Lei; Wang, Jing

    2014-10-01

    The study is to explore the effect of total glucosides of paeony (TGP)on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats, and discuss the protection of TGP in diabetic nephropathy and possible mechanism. Ninety male SD rats of 8 weeks age were randomly divided into normal control group (n = 10) and model group (n = 80). Rats of the normal control group were fed with regular diet, while rats of the model group were fed with high-fat high-sugar diet and 4 weeks later were given an intraperitoneal injection of 35 mg x kg(-1) streptozotocin (STZ). The successfully induced type 2 diabetic rat models were then randomly divided into DM group, three TGP (50, 100, 200 mg x kg(-1) x d(-1)) treatment group and tripterygium wilfordii glycosides (8 mg x kg(-1) x d(-1)) control group. Rats of DM group and each treatment group were given high-fat high-sugar diet. At week 14, the levels of blood sugar, 24 hour urine protein, serum creatinine and blood urea nitrogen were tested. The rats were then sacrificed. Renal pathological changes were examined. Renal tissue Wnt-1 and β-catenin expressions were detected by immunohistochemical assay. Wnt-1 mRNA and β-catenin mRNA expression was semi-quantified by RT-PCR. Wnt-1 protein and β-catenin protein expression was semi-quantified by Western blot. The Result show that Wnt-1 and β-catenin expression increased in kidney of high-fat high-sugar induced type 2 diabetic rats. Compared with diabetic group, the level of serum creatinine, blood urea nitrogen, 24 h urine protein, mean glomerular area and mean glomerular volume were decreased, renal histopathology were improved, expression of Wnt-1 and β-catenin mRNA and protein was reduced in TGP group. Tripterygium wilfordii glycosides had the similar effect. In conclusion, these results showed that Wnt/β-catenin abnormal activation in kidney of type 2 diabetic rats, TGP can improve kidney damage in diabetic rats and delay the development of diabetic

  8. Minoxidil activates β-catenin pathway in human dermal papilla cells: a possible explanation for its anagen prolongation effect.

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    Kwack, Mi Hee; Kang, Bo Mi; Kim, Moon Kyu; Kim, Jung Chul; Sung, Young Kwan

    2011-06-01

    It is believed that the length of the actively growing phase of the anagen hair cycle mainly contributes to hair length. Recent studies showed that maintenance of β-catenin activity in the dermal papilla cells (DPCs) enables hair follicles to keep actively growing. Topical minoxidil treatment promotes hair growth in men with androgenetic alopecia, suggesting that minoxidil may prolong the actively growing phase of the anagen hair cycle. To investigate whether minoxidil prolongs the anagen hair cycle in mice and, if so, to investigate whether minoxidil activates β-catenin pathway in human DPCs. Dorsal skins of C57BL/6 mice were depilated to synchronize the hair cycle. After 10 days, 3% minoxidil were topically applied daily for 10 days. Sections of back skins were stained with hematoxylin and eosin. Hair follicles were graded and hair cycle score (HCS) was calculated. Cultured human DPCs were transiently transfected with the β-catenin responsive TCF reporter plasmid (pTopflash) and corresponding negative control reporter (pFopflash) to assess the activity of β-catenin signaling by minoxidil. Immunofluorescence staining and immunoblot were performed to examine the expression and localization of β-catenin in the presence or absence of minoxidil. Phosphorylation of GSK3β, PKA and PKB were also examined by immunoblot after minoxidil treatment. RT-PCR analysis and immunoblot were employed to investigate the expression of β-catenin pathway targets in DPCs, such as Axin2, Lef-1, and EP2. Modest extension of anagen phase thereby delay of catagen progression was observed by application of minoxidil in mice. Minoxidil stimulated the transcriptional activity of pTopflash but not pFopflash. Nuclear accumulation of β-catenin was also observed after minoxidil treatment. Immunoblot further showed that minoxidil treatment increases the phosphorylation of GSK3β, PKA and PKB. Moreover, minoxidil induced Axin2, Lef-1, and EP2 expression. Our results strongly suggest that

  9. 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

  10. Paracrine Activation of the Wnt/β-Catenin Pathway by Bone Marrow Stem Cell Attenuates Cisplatin-Induced Kidney Injury.

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    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

  11. 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

  12. Distinct patterns of ALDH1A1 expression predict metastasis and poor outcome of colorectal carcinoma

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    Xu, Sen-Lin; Zeng, Dong-Zu; Dong, Wei-Guo; Ding, Yan-Qing; Rao, Jun; Duan, Jiang-Jie; Liu, Qing; Yang, Jing; Zhan, Na; Liu, Ying; Hu, Qi-Ping; Zhang, Xia; Cui, You-Hong; Kung, Hsiang-Fu; Yu, Shi-Cang; Bian, Xiu-Wu

    2014-01-01

    Purpose: Aldehyde dehydrogenase 1A1 (ALDH1A1) has been proposed as a candidate biomarker for colorectal carcinoma (CRC). However, the heterogeneity of its expression makes it difficult to predict the outcome of CRC. The aim of this study was to evaluate the diagnostic and prognostic value of this molecule in CRC. Methods and Results: In this study, we examined ALDH1A1 expression by immunohistochemistry including 406 cases of primary CRC with corresponding adjacent mucosa, with confirmation of real-time PCR and Western blotting. We found that the expression patterns of ALDH1A1 were heterogeneous in the CRC and corresponding adjacent tissues. We defined the ratio of ALDH1A1 level in adjacent mucosa to that in tumor tissues as RA/C and found that the capabilities of tumor invasion and metastasis in the tumors with RA/C < 1 were significantly higher than those with RA/C ≥ 1. Follow-up data showed the worse prognoses in the CRC patients with RA/C < 1. For understanding the underlying mechanism, the localization of β-catenin was detected in the CRC tissues with different patterns of ALDH1A1 expression from 221 patients and β-catenin was found preferentially expressed in cell nuclei of the tumors with RA/C < 1 and ALDH1A1high expression of HT29 cell line, indicating that nuclear translocation of β-catenin might contribute to the increased potentials of invasion and metastasis. Conclusion: Our results indicate that RA/C is a novel biomarker to reflect the distinct expression patterns of ALDH1A1 for predicting metastasis and prognosis of CRC. PMID:25031716

  13. Impaired degradation of inhibitory subunit of NF-κB (IκB) and β-catenin as a result of targeted disruption of the β-TrCP1 gene

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    Nakayama, Keiko; Hatakeyama, Shigetsugu; Maruyama, Shun-ichiro; Kikuchi, Akira; Onoé, Kazunori; Good, Robert A.; Nakayama, Keiichi I.

    2003-01-01

    β-TrCP1 (also known as Fbw1a or FWD1) is the F-box protein component of an Skp1/Cul1/F-box (SCF)-type ubiquitin ligase complex. Although biochemical studies have suggested that β-TrCP1 targets inhibitory subunit of NF-κB(IκB) proteins and β-catenin for ubiquitylation, the physiological role of β-TrCP1 in mammals has remained unclear. We have now generated mice deficient in β-TrCP1 and shown that the degradation of IκBα and IκBβ is reproducibly, but not completely, impaired in the cells of these animals. The nuclear translocation and DNA-binding activity of NF-κB as well as the ability of this transcription factor to activate a luciferase reporter gene were also inhibited in β-TrCP1–/– cells compared with those apparent in wild-type cells. The subcellular localization of β-catenin was altered markedly in β-TrCP1–/– cells. Furthermore, the rate of proliferation was reduced and both cell size and the percentage of polyploid cells were increased in embryonic fibroblasts derived from β-TrCP1–/– mice pared with the corresponding wild-type cells. These results suggest that β-TrCP1 contributes to, but is not absolutely required for, the degradation of IκB and β-catenin and the consequent regulation of the NF-κB and Wnt signaling pathways, respectively. In addition, they implicate β-TrCP1 in the maintenance of ploidy during cell-cycle progression. PMID:12843402

  14. HMP-1/α-catenin promotes junctional mechanical integrity during morphogenesis.

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    Thanh Thi Kim Vuong-Brender

    Full Text Available Adherens junctions (AJs are key structures regulating tissue integrity and maintaining adhesion between cells. During morphogenesis, junctional proteins cooperate closely with the actomyosin network to drive cell movement and shape changes. How the junctions integrate the mechanical forces in space and in time during an in vivo morphogenetic event is still largely unknown, due to a lack of quantitative data. To address this issue, we inserted a functional Fluorescence Resonance Energy Transfer (FRET-based force biosensor within HMP-1/α-catenin of Caenorhabditis elegans. We find that the tension exerted on HMP-1 has a cell-specific distribution, is actomyosin-dependent, but is regulated differently from the tension on the actin cortex during embryonic elongation. By using time-lapse analysis of mutants and tissue-specific rescue experiments, we confirm the role of VAB-9/Claudin as an actin bundle anchor. Nevertheless, the tension exerted on HMP-1 did not increase in the absence of VAB-9/Claudin, suggesting that HMP-1 activity is not upregulated to compensate for loss of VAB-9. Our data indicate that HMP-1 does not modulate HMR-1/E-cadherin turnover, is required to recruit junctional actin but not stress fiber-like actin bundles. Altogether, our data suggest that HMP-1/α-catenin acts to promote the mechanical integrity of adherens junctions.

  15. 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.

  16. Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation.

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    Katharina Felber

    Full Text Available Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF and canonical Wingless-type MMTV integration site (Wnt/β-Catenin signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx. We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation.

  17. Fusion of the BCL9 HD2 domain to E1A increases the cytopathic effect of an oncolytic adenovirus that targets colon cancer cells

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    Pittet Anne-Laure

    2006-10-01

    Full Text Available Abstract Background The Wnt signaling pathway is activated by mutations in the APC and β-catenin genes in many types of human cancer. β-catenin is stabilized by these mutations and activates transcription in part by acting as a bridge between Tcf/LEF proteins and the HD2 domain of the BCL9 coactivator. We have previously described oncolytic adenoviruses with binding sites for Tcf/LEF transcription factors inserted into the early viral promoters. These viruses replicate selectively in cells with activation of the Wnt pathway. To increase the activity of these viruses we have fused the viral transactivator E1A to the BCL9 HD2 domain. Methods Luciferase assays, co-immunoprecipitation and Western blotting, immunofluorescent cell staining and cytopathic effect assays were used to characterize the E1A-HD2 fusion protein and virus in vitro. Growth curves of subcutaneous SW620 colon cancer xenografts were used to characterize the virus in vivo. Results The E1A-HD2 fusion protein binds to β-catenin in vivo and activates a Tcf-regulated luciferase reporter better than wild-type E1A in cells with activated Wnt signaling. Expression of the E1A-HD2 protein promotes nuclear import of β-catenin, mediated by the strong nuclear localization signal in E1A. Tcf-regulated viruses expressing the fusion protein show increased expression of viral proteins and a five-fold increase in cytopathic effect (CPE in colorectal cancer cell lines. There was no change in viral protein expression or CPE in HeLa cells, indicating that E1A-HD2 viruses retain selectivity for cells with activation of the Wnt signaling pathway. Despite increasing the cytopathic effect of the virus in vitro, fusion of the HD2 domain to E1A did not increase the burst size of the virus in vitro or the anti-tumor effect of the virus in an SW620 xenograft model in vivo. Conclusion Despite an increase in the nuclear pool of β-catenin, the effects on viral activity in colon cancer cells were small

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

    International Nuclear Information System (INIS)

    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.

  19. Nanorod diameter modulated osteogenic activity of hierarchical micropore/nanorod-patterned coatings via a Wnt/β-catenin pathway.

    Science.gov (United States)

    Zhou, Jianhong; Zhao, Lingzhou; Li, Bo; Han, Yong

    2018-04-14

    Hierarchical micropore/nanorod-patterned strontium doped hydroxyapatite (Ca 9 Sr 1 (PO 4 ) 6 (OH) 2 , Sr 1 -HA) structures (MNRs) with different nanorod diameters of about 30, 70 and 150 nm were coated on titanium, to investigate the effect of nanorod diameter on osteogenesis and the involved mechanism. Compared to micropore/nanogranule-patterned Sr 1 -HA coating (MNG), MNRs gave rise to dramatically enhanced in vitro mesenchymal stem cell functions including osteogenic differentiation in the absence of osteogenic supplements and in vivo osseointegration related to the nanorod diameter with about 70 nm displaying the best effects. MNRs activated the cellular Wnt/β-catenin pathway by increasing the expression of Wnt3a and LRP6 and decreasing the expression of Wnt/β-catenin pathway antagonists (sFRP1, sFRP2, Dkk1 and Dkk2). The exogenous Wnt3a significantly enhanced the β-catenin signaling activation and cell differentiation on MNG, and the exogenous Dkk1 attenuated the enhancing effect of MNRs on them. The data demonstrate that MNRs favor osseointegration via a Wnt/β-catenin pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. The Role of Chromosomal Instability and Epigenetics in Colorectal Cancers Lacking β-Catenin/TCF Regulated Transcription

    Directory of Open Access Journals (Sweden)

    Wael M. Abdel-Rahman

    2016-01-01

    Full Text Available All colorectal cancer cell lines except RKO displayed active β-catenin/TCF regulated transcription. This feature of RKO was noted in familial colon cancers; hence our aim was to dissect its carcinogenic mechanism. MFISH and CGH revealed distinct instability of chromosome structure in RKO. Gene expression microarray of RKO versus 7 colon cancer lines (with active Wnt signaling and 3 normal specimens revealed 611 differentially expressed genes. The majority of the tested gene loci were susceptible to LOH in primary tumors with various β-catenin localizations as a surrogate marker for β-catenin activation. The immunohistochemistry of selected genes (IFI16, RGS4, MCTP1, DGKI, OBCAM/OPCML, and GLIPR1 confirmed that they were differentially expressed in clinical specimens. Since epigenetic mechanisms can contribute to expression changes, selected target genes were evaluated for promoter methylation in patient specimens from sporadic and hereditary colorectal cancers. CMTM3, DGKI, and OPCML were frequently hypermethylated in both groups, whereas KLK10, EPCAM, and DLC1 displayed subgroup specificity. The overall fraction of hypermethylated genes was higher in tumors with membranous β-catenin. We identified novel genes in colorectal carcinogenesis that might be useful in personalized tumor profiling. Tumors with inactive Wnt signaling are a heterogeneous group displaying interaction of chromosomal instability, Wnt signaling, and epigenetics.

  1. 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.

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

    Science.gov (United States)

    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.

  3. The Wnt/β-catenin signaling pathway tips the balance between apoptosis and reprograming of cell fusion hybrids.

    Science.gov (United States)

    Lluis, Frederic; Pedone, Elisa; Pepe, Stefano; Cosma, Maria Pia

    2010-11-01

    Cell-cell fusion contributes to cell differentiation and developmental processes. We have previously showed that activation of Wnt/β-catenin enhances somatic cell reprograming after polyethylene glycol (PEG)-mediated fusion. Here, we show that neural stem cells and ESCs can fuse spontaneously in cocultures, although with very low efficiency (about 2%), as the hybrids undergo apoptosis. In contrast, when Wnt/β-catenin signaling is activated in ESCs and leads to accumulation of low amounts of β-catenin in the nucleus, activated ESCs can reprogram somatic cells with very high efficiency after spontaneous fusion. Furthermore, we also show that different levels of β-catenin accumulation in the ESC nuclei can modulate cell proliferation, although in our experimental setting, cell proliferation does not modulate the reprograming efficiency per se. Overall, the present study provides evidence that spontaneous fusion occurs, while the survival of the reprogramed clones is strictly dependent on induction of a Wnt-mediated reprograming pathway. Copyright © 2010 AlphaMed Press.

  4. β-Catenin Regulates Primitive Streak Induction through Collaborative Interactions with SMAD2/SMAD3 and OCT4

    DEFF Research Database (Denmark)

    Funa, Nina Sofi Ayumi; Schachter, Karen; Lerdrup, Mads

    2015-01-01

    Canonical Wnt and Nodal signaling are both required for induction of the primitive streak (PS), which guides organization of the early embryo. The Wnt effector b-catenin is thought to function in these early lineage specification decisions via transcriptional activation of Nodal signaling. Here, we...... specification. This study provides mechanistic insight into how Wnt signaling controls early cell lineage decisions....

  5. 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.

  6. RSPO1/β-catenin signaling pathway regulates oogonia differentiation and entry into meiosis in the mouse fetal ovary.

    Directory of Open Access Journals (Sweden)

    Anne-Amandine Chassot

    Full Text Available Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog gene and factors synthesized by the somatic Sertoli cells promote gonocyte differentiation. In the female, ovarian differentiation requires activation of the WNT/β-catenin signaling pathway in the somatic cells by the secreted protein RSPO1. Using mouse models, we now show that Rspo1 also activates the WNT/β-catenin signaling pathway in germ cells. In XX Rspo1(-/- gonads, germ cell proliferation, expression of the early meiotic marker Stra8, and entry into meiosis are all impaired. In these gonads, impaired entry into meiosis and germ cell sex reversal occur prior to detectable Sertoli cell differentiation, suggesting that β-catenin signaling acts within the germ cells to promote oogonial differentiation and entry into meiosis. Our results demonstrate that RSPO1/β-catenin signaling is involved in meiosis in fetal germ cells and contributes to the cellular decision of germ cells to differentiate into oocyte or sperm.

  7. 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

  8. 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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. 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.

  13. Bilobalide induces neuronal differentiation of P19 embryonic carcinoma cells via activating Wnt/β-catenin pathway.

    Science.gov (United States)

    Liu, Mei; Guo, Jingjing; Wang, Juan; Zhang, Luyong; Pang, Tao; Liao, Hong

    2014-08-01

    Bilobalide, a natural product extracted from Ginkgo biloba leaf, is known to exhibit a number of pharmacological activities. So far, whether it could affect embryonic stem cell differentiation is still unknown. The main aim of this study was to investigate the effect of bilobalide on P19 embryonic carcinoma cells differentiation and the underlying mechanisms. Our results showed that bilobalide induced P19 cells differentiation into neurons in a concentration- and time-dependent manner. We also found that bilobalide promoted neuronal differentiation through activation of Wnt/β-catenin signaling pathway. Exposure to bilobalide increased inactive GSK-3β phosphorylation, further induced the nuclear accumulation of β-catenin, and also up-regulated the expression of Wnt ligands Wnt1 and Wnt7a. Neuronal differentiation induced by bilobalide was totally abolished by XAV939, an inhibitor of Wnt/β-catenin pathway. These results revealed a novel role of bilobalide in neuronal differentiation from P19 embryonic cells acting through Wnt/β-catenin signaling pathway, which would provide a better insight into the beneficial effects of bilobalide in brain diseases.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. HER2 and β-catenin protein location: importance in the prognosis of breast cancer patients and their correlation when breast cancer cells suffer stressful situations.

    Science.gov (United States)

    Cuello-Carrión, F Darío; Shortrede, Jorge E; Alvarez-Olmedo, Daiana; Cayado-Gutiérrez, Niubys; Castro, Gisela N; Zoppino, Felipe C M; Guerrero, Martín; Martinis, Estefania; Wuilloud, Rodolfo; Gómez, Nidia N; Biaggio, Verónica; Orozco, Javier; Gago, Francisco E; Ciocca, Leonardo A; Fanelli, Mariel A; Ciocca, Daniel R

    2015-02-01

    In human breast cancer, β-catenin localization has been related with disease prognosis. Since HER2-positive patients are an important subgroup, and that in breast cancer cells a direct interaction of β-catenin/HER2 has been reported, in the present study we have explored whether β-catenin location is related with the disease survival. The study was performed in a tumor bank from patients (n = 140) that did not receive specific anti-HER2 therapy. The proteins were detected by immunohistochemistry in serial sections, 47 (33.5%) patients were HER2-positive with a long follow-up. HER2-positive patients that displayed β-catenin at the plasma membrane (completely surrounding the tumour cells) showed a significant better disease-free survival and overall survival than the patients showing the protein on other locations. Then we explored the dynamics of the co-expression of β-catenin and HER2 in human MCF-7 and SKBR3 cells exposed to different stressful situations. In untreated conditions MCF-7 and SKBR3 cells showed very different β-catenin localization. In MCF-7 cells, cadmium administration caused a striking change in β-catenin localization driving it from plasma membrane to cytoplasmic and perinuclear areas and HER2 showed a similar localization patterns. The changes induced by cadmium were compared with heat shock, H2O2 and tamoxifen treatments. In conclusion, this study shows the dynamical associations of HER2 and β-catenin and their changes in subcellular localizations driven by stressful situations. In addition, we report for the first time the correlation between plasma membrane associated β-catenin in HER2-positive breast cancer and survival outcome, and the importance of the protein localization in breast cancer samples.

  16. Lysophosphatidic acid modulates the association of PTP1B with N-cadherin/catenin complex in SKOV3 ovarian cancer cells.

    Science.gov (United States)

    Huang, Ruby Yun-Ju; Wen, Chen-Chen; Liao, Chih-Kai; Wang, Shu-Huei; Chou, Liang-Yin; Wu, Jiahn-Chun

    2012-09-01

    LPA (lysophosphatidic acid) is a natural phospholipid that plays important roles in promoting cancer cell proliferation, invasion and metastases. We previously reported that LPA induces ovarian cancer cell dispersal and disruption of AJ (adherens junction) through the activation of SFK (Src family kinases). In this study, we have investigated the regulatory mechanisms during the early phase of LPA-induced cell dispersal. An in vitro model of the ovarian cancer cell line SKOV3 for cell dispersal was used. LPA induces rapid AJ disruption by increasing the internalization of N-cadherin-β-catenin. By using immunoprecipitations, LPA was shown to induce increased tyrosine phosphorylation of β-catenin and alter the balance of β-catenin-bound SFK and PTP1B (phosphotyrosine phosphatase 1B). The altered balance of tyrosine kinase/phosphatase correlated with a concomitant disintegration of the β-catenin-α-catenin, but not the β-catenin-N-cadherin complex. This disintegration of β-catenin from α-catenin and the cell dispersal caused by LPA can be rescued by blocking SFK activity with the chemical inhibitor, PP2. More importantly, PP2 also restores the level of PTP1B bound to β-catenin. We propose that LPA signalling alters AJ stability by changing the dynamics of tyrosine kinase/phosphatase bound to AJ proteins. This work provides further understanding of the early signalling events regulating ovarian cancer cell dispersal and AJ disruption induced by LPA. © The Author(s) Journal compilation © 2012 International Federation for Cell Biology.

  17. Combination effects of AHR agonists and Wnt/β-catenin modulators in zebrafish embryos: Implications for physiological and toxicological AHR functions

    Energy Technology Data Exchange (ETDEWEB)

    Wincent, Emma [Department of Environmental Toxicology, Uppsala University, 75236 Uppsala (Sweden); Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm (Sweden); Stegeman, John J. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050 (United States); Jönsson, Maria E., E-mail: maria.jonsson@ebc.uu.se [Department of Environmental Toxicology, Uppsala University, 75236 Uppsala (Sweden)

    2015-04-15

    Wnt/β-catenin signaling regulates essential biological functions and acts in developmental toxicity of some chemicals. The aryl hydrocarbon receptor (AHR) is well-known to mediate developmental toxicity of persistent dioxin-like compounds (DLCs). Recent studies indicate a crosstalk between β-catenin and the AHR in some tissues. However the nature of this crosstalk in embryos is poorly known. We observed that zebrafish embryos exposed to the β-catenin inhibitor XAV939 display effects phenocopying those of the dioxin-like 3,3′,4,4′,5-pentachlorobiphenyl (PCB126). This led us to investigate the AHR interaction with β-catenin during development and ask whether developmental toxicity of DLCs involves antagonism of β-catenin signaling. We examined phenotypes and transcriptional responses in zebrafish embryos exposed to XAV939 or to a β-catenin activator, 1-azakenpaullone, alone or with AHR agonists, either PCB126 or 6-formylindolo[3,2-b]carbazole (FICZ). Alone 1-azakenpaullone and XAV939 both were embryo-toxic, and we found that in the presence of FICZ, the toxicity of 1-azakenpaullone decreased while the toxicity of XAV939 increased. This rescue of 1-azakenpaullone effects occurred in the time window of Ahr2-mediated toxicity and was reversed by morpholino-oligonucleotide knockdown of Ahr2. Regarding PCB126, addition of either 1-azakenpaullone or XAV939 led to lower mortality than with PCB126 alone but surviving embryos showed severe edemas. 1-Azakenpaullone induced transcription of β-catenin-associated genes, while PCB126 and FICZ blocked this induction. The data indicate a stage-dependent antagonism of β-catenin by Ahr2 in zebrafish embryos. We propose that the AHR has a physiological role in regulating β-catenin during development, and that this is one point of intersection linking toxicological and physiological AHR-governed processes.

  18. Effects of short-hairpin RNA-inhibited {beta}-catenin expression on the growth of human multiple myeloma cells in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wenqing, E-mail: liangwenqing_1234@126.com [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Yang, Chengwei [Department of Spinal Surgery, Lanzhou General Hospital, Lanzhou Military Area Command, 333 Nanbinhe Road, Lanzhou 730050 (China); Qian, Yu [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Fu, Qiang, E-mail: chyygklwq@hotmail.com [Department of Orthopaedics, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer {beta}-Catenin expression were markedly down-regulated by CTNNB1 shRNA. Black-Right-Pointing-Pointer CTNNB1 shRNA could inhibit the proliferation of RPMI8226 cells. Black-Right-Pointing-Pointer Significantly profound apoptotic cell death in CTNNB1 shRNA cells. Black-Right-Pointing-Pointer In vivo, CTNNB1 silence led to a growth inhibition of myeloma growth. Black-Right-Pointing-Pointer c-myc and {beta}-catenin in the expression cells of cleaved caspase-3 were increased. -- Abstract: Multiple myeloma (MM) is thrombogenic as a consequence of multiple hemostatic effects. Overexpression of {beta}-catenin has been observed in several types of malignant tumors, including MM. However, the relationship between {beta}-catenin expression and MM remains unclear. In the present study, RNA interference was used to inhibit {beta}-catenin expression in RPMI8226 cells. RT-PCR and Western blotting analyses showed that {beta}-catenin mRNA and protein expression were markedly down-regulated by CTNNB1 shRNA. Western blotting showed that the protein levels of cyclin D1 and glutamine synthetase were downregulated and supported the transcriptional regulatory function of {beta}-catenin. The MTT assay showed that CTNNB1 shRNA could have significant inhibitory effects on the proliferation of RPMI8226 cells. The TOPflash reporter assay demonstrated significant downregulation after CTNNB1 shRNA transfection in RPMI8226 cells. Flow cytometric analyses also showed significantly profound apoptosis in CTNNB1 shRNA cells. We found CTNNB1 silence led to growth inhibition of MM growth in vivo. Immunohistochemical analyses showed that c-myc and {beta}-catenin were reduced in CTNNB1 shRNA tumor tissues, but that expression of cleaved caspase-3 was increased. These results show that {beta}-catenin could be a new therapeutic agent that targets the biology of MM cells.

  19. A hypermorphic epithelial β-catenin mutation facilitates intestinal tumorigenesis in mice in response to compounding WNT-pathway mutations

    Directory of Open Access Journals (Sweden)

    Michael Buchert

    2015-11-01

    Full Text Available Activation of the Wnt/β-catenin pathway occurs in the vast majority of colorectal cancers. However, the outcome of the disease varies markedly from individual to individual, even within the same tumor stage. This heterogeneity is governed to a great extent by the genetic make-up of individual tumors and the combination of oncogenic mutations. In order to express throughout the intestinal epithelium a degradation-resistant β-catenin (Ctnnb1, which lacks the first 131 amino acids, we inserted an epitope-tagged ΔN(1-131-β-catenin-encoding cDNA as a knock-in transgene into the endogenous gpA33 gene locus in mice. The resulting gpA33ΔN-Bcat mice showed an increase in the constitutive Wnt/β-catenin pathway activation that shifts the cell fate towards the Paneth cell lineage in pre-malignant intestinal epithelium. Furthermore, 19% of all heterozygous and 37% of all homozygous gpA33ΔN-Bcat mice spontaneously developed aberrant crypt foci and adenomatous polyps, at frequencies and latencies akin to those observed in sporadic colon cancer in humans. Consistent with this, the Wnt target genes, MMP7  and Tenascin-C, which are most highly expressed in benign human adenomas and early tumor stages, were upregulated in pre-malignant tissue of gpA33ΔN-Bcat mice, but those Wnt target genes associated with excessive proliferation (i.e. Cdnn1, myc were not. We also detected diminished expression of membrane-associated α-catenin and increased intestinal permeability in gpA33ΔN-Bcat mice in challenge conditions, providing a potential explanation for the observed mild chronic intestinal inflammation and increased susceptibility to azoxymethane and mutant Apc-dependent tumorigenesis. Collectively, our data indicate that epithelial expression of ΔN(1-131-β-catenin in the intestine creates an inflammatory microenvironment and co-operates with other mutations in the Wnt/β-catenin pathway to facilitate and promote tumorigenesis.

  20. Rac1/β-Catenin Signalling Pathway Contributes to Trophoblast Cell Invasion by Targeting Snail and MMP9

    Directory of Open Access Journals (Sweden)

    Minghua Fan

    2016-03-01

    Full Text Available Background/Aims: Preeclampsia is an idiopathic and serious complication during gestation in which placental trophoblast cells differentiate into several functional subtypes, including highly invasive extravillous trophoblasts (EVTs. Although the cause and pathogenesis of preeclampsia have remained unclear, numerous studies have suggested that the inadequacy of EVT invasion leads to imperfect uterine spiral artery remodelling, which plays a crucial role in the development of preeclampsia. Rac1, or Ras-related C3 botulinum toxin substrate 1, was found to be a key regulator of the migration, invasion uand apoptosis of various tumour cells. Because EVTs share similar invasive and migratory biological behaviours with malignant cells, this study aimed to determine whether the Rac1 signalling pathway affects trophoblast invasion and is thus involved in the pathogenesis of preeclampsia. Methods: We measured the activity of Rac1 and its downstream targets, β-catenin, Snail and MMP9 in placental tissues from patients experiencing a normal pregnancy and those with preeclampsia. Furthermore, we treated HTR-8/SVneo cells with a shRNA Rac1 vector and the β-catenin inhibitor IWP-2 and explored Rac1 signalling pathway activation as well as the effects of Snail and β-catenin on trophoblast invasion. Results: In placental samples from patients experiencing a normal pregnancy and those with preeclampsia, active Rac1 levels and MMP9 protein and mRNA levels were significantly decreased in term pregnancy samples compared to early pregnancy samples. Lower levels were found in preeclampsia samples than in normal term pregnancy samples, and these levels significantly declined in severe preeclampsia samples compared with mild preeclampsia samples. Further analyses demonstrated that both Rac1 shRNA and the β-catenin inhibitor significantly suppressed MMP9 and Snail activation in trophoblasts, thus impairing trophoblast invasion. Notably, silencing Rac1 down

  1. 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

  2. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Indirect effects of Wnt3a/β-catenin signalling support mouse spermatogonial stem cells in vitro.

    Directory of Open Access Journals (Sweden)

    Jonathan R Yeh

    Full Text Available Proper regulation of spermatogonial stem cells (SSCs is crucial for sustaining steady-state spermatogenesis. Previous work has identified several paracrine factors involved in this regulation, in particular, glial cell line-derived neurotrophic factor and fibroblast growth factor 2, which promote long-term SSC self-renewal. Using a SSC culture system, we have recently reported that Wnt5a promotes SSC self-renewal through a β-catenin-independent Wnt mechanism whereas the β-catenin-dependent Wnt pathway is not active in SSCs. In contrast, another study has reported that Wnt3a promotes SSC self-renewal through the β-catenin-dependent pathway, as it can stimulate the proliferation of a spermatogonia cell line. To reconcile these two contradictory reports, we assessed Wnt3a effects on SSCs and progenitor cells, rather than a cell line, in vitro. We observed that Wnt3a induced β-catenin-dependent signalling in a large subset of germ cells and increased SSC numbers. However, further investigation revealed that cell populations with greater β-catenin-signalling activity contained fewer SSCs. The increased maintenance of SSCs by Wnt3a coincided with more active cell cycling and the formation of germ cell aggregates, or communities, under feeder-free conditions. Therefore, the results of this study suggest that Wnt3a selectively stimulates proliferation of progenitors that are committed to differentiation or are in the process of exiting the SSC state, leading to enhanced formation of germ cell communities, which indirectly support SSCs and act as an in vitro niche.

  10. BAG3 promotes chondrosarcoma progression by upregulating the expression of β-catenin

    Science.gov (United States)

    Shi, Huijuan; Chen, Wenfang; Dong, Yu; Lu, Xiaofang; Zhang, Wenhui; Wang, Liantang

    2018-01-01

    To investigate the roles of B-cell lymphoma-2 associated athanogene 3 (BAG3) in human chondrosarcoma and the potential mechanisms, the expression levels of BAG3 were detected in the present study, and the associations between BAG3 and clinical pathological parameters, clinical stage as well as the survival of patients were analyzed. The present study detected BAG3 mRNA and protein expression in the normal cartilage cell line HC-a and in SW1353 chondrosarcoma cells by reverse transcription-quantitative polymerase chain reaction and western blot analysis. The BAG3 protein expression in 59 cases of chondrosarcoma, 30 patients with endogenous chondroma and 8 cases of normal cartilage was semi-quantitatively analyzed using the immunohistochemical method. In addition, the BAG3 protein expression level, the clinical pathological parameters, clinical stage and the survival time of patients with chondrosarcoma were analyzed. The plasmid transfection method was employed to upregulate the expression BAG3 and small RNA interference to downregulate the expression of BAG3 in SW1353 cells. The expression levels of BAG3 protein and mRNA were significantly increased in the chondrosarcoma cell line when compared with the normal cartilage cell line. The immunohistochemistry results indicated that BAG3 protein was overexpressed in the tissue of human chondrosarcoma. Statistical analysis showed that the expression level of BAG3 was significantly increased in the different Enneking staging of patients with chondrosarcoma and Tumor staging, and there were no statistical differences in age, gender, histological classification and tumor size. In the in vitro experiments, the data revealed that BAG3 significantly promoted chondrosarcoma cell proliferation, colony-formation, migration and invasion; however, it inhibited chondrosarcoma cell apoptosis. It was observed that BAG3 upregulated β-catenin expression at the mRNA and protein levels. In addition, BAG3 induced the expression of runt

  11. BAG3 promotes chondrosarcoma progression by upregulating the expression of β-catenin.

    Science.gov (United States)

    Shi, Huijuan; Chen, Wenfang; Dong, Yu; Lu, Xiaofang; Zhang, Wenhui; Wang, Liantang

    2018-04-01

    To investigate the roles of B‑cell lymphoma‑2 associated athanogene 3 (BAG3) in human chondrosarcoma and the potential mechanisms, the expression levels of BAG3 were detected in the present study, and the associations between BAG3 and clinical pathological parameters, clinical stage as well as the survival of patients were analyzed. The present study detected BAG3 mRNA and protein expression in the normal cartilage cell line HC‑a and in SW1353 chondrosarcoma cells by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. The BAG3 protein expression in 59 cases of chondrosarcoma, 30 patients with endogenous chondroma and 8 cases of normal cartilage was semi-quantitatively analyzed using the immunohistochemical method. In addition, the BAG3 protein expression level, the clinical pathological parameters, clinical stage and the survival time of patients with chondrosarcoma were analyzed. The plasmid transfection method was employed to upregulate the expression BAG3 and small RNA interference to downregulate the expression of BAG3 in SW1353 cells. The expression levels of BAG3 protein and mRNA were significantly increased in the chondrosarcoma cell line when compared with the normal cartilage cell line. The immunohistochemistry results indicated that BAG3 protein was overexpressed in the tissue of human chondrosarcoma. Statistical analysis showed that the expression level of BAG3 was significantly increased in the different Enneking staging of patients with chondrosarcoma and Tumor staging, and there were no statistical differences in age, gender, histological classification and tumor size. In the in vitro experiments, the data revealed that BAG3 significantly promoted chondrosarcoma cell proliferation, colony‑formation, migration and invasion; however, it inhibited chondrosarcoma cell apoptosis. It was observed that BAG3 upregulated β‑catenin expression at the mRNA and protein levels. In addition, BAG3 induced the

  12. Distribution of E-cadherin and ß-catenin in relation to cell maturation and cell extrusion in rat and mouse small intestines

    DEFF Research Database (Denmark)

    Larsson, Lars-Inge

    2006-01-01

    of programmed cell death (PCD) in mouse small intestinal epithelium. We have studied if this also occurs in the intact rodent small intestine. Our results confirm that extruded cells are negatie for E-cadherin. However, loss of the E-cadherin-interacting protein ß-cetenin preceded both extrusion and loss of E......-cadherin. Thus, all extruded cells as well as all cells in the process of extrusion lacked staining for ß-catenin. Moreover, almost 80% of all cells undergoing programmed cell death, as detected by the TUNEL reaction, lacked ß-catenin whereas over 70% of such cells were positive for E-cadherin. However, most...... ells lacking ß-catenin did not display signs of PCD as detected by the TUNEL method or by staining for active caspase-3. Therefore, these results suggest that loss of ß-catenin precedes the onset of programmed cell death, loss of E-cadherin and extrusion from the villi....

  13. Normal hematopoiesis and lack of β-catenin activation in osteoblasts of patients and mice harboring Lrp5 gain of function mutations

    DEFF Research Database (Denmark)

    Galan-Diez, Marta; Isa, Adiba; Ponzetti, Marco

    2016-01-01

    of hematopoiesis and leukemogenic properties of β-catenin activation in osteoblasts, that lead to development of acute myeloid leukemia (AML). Using mice with gain-of-function (GOF) Lrp5 alleles (Lrp5(A214V)) that recapitulate the human high bone mass (HBM) phenotype, as well as patients with the T253I HBM Lrp5...... mutation, we show here that Lrp5 GOF mutations in both humans and mice do not activate β-catenin signaling in osteoblasts. Consistent with a lack of β-catenin activation in their osteoblasts, Lrp5(A214V) mice have normal trilinear hematopoiesis. In contrast to leukemic mice with constitutive activation...... of β-catenin in osteoblasts (Ctnnb1(CAosb)), accumulation of early myeloid progenitors, a characteristic of AML, myeloid-blasts in blood, and segmented neutrophils or dysplastic megakaryocytes in the bone marrow, are not observed in Lrp5(A214V) mice. Likewise, peripheral blood count analysis in HBM...

  14. 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...

  15. 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...

  16. 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.

  17. Differential effects of β-catenin and NF-κB interplay in the regulation of cell proliferation, inflammation and tumorigenesis in response to bacterial infection.

    Directory of Open Access Journals (Sweden)

    Parthasarathy Chandrakesan

    Full Text Available Both β-catenin and NF-κB have been implicated in our laboratory as candidate factors in driving proliferation in an in vivo model of Citrobacter rodentium (CR-induced colonic crypt hyper-proliferation and hyperplasia. Herein, we test the hypothesis that β-catenin and not necessarily NF-κB regulates colonic crypt hyperplasia or tumorigenesis in response to CR infection. When C57Bl/6 wild type (WT mice were infected with CR, sequential increases in proliferation at days 9 and 12 plateaued off at day 19 and paralleled increases in NF-κB signaling. In Tlr4(-/- (KO mice, a sequential but sustained proliferation which tapered off only marginally at day 19, was associated with TLR4-dependent and independent increases in NF-κB signaling. Similarly, increases in either activated or total β-catenin in the colonic crypts of WT mice as early as day 3 post-infection coincided with cyclinD1 and c-myc expression and associated crypt hyperplasia. In KO mice, a delayed kinetics associated predominantly with increases in non-phosphorylated (active β-catenin coincided with increases in cyclinD1, c-myc and crypt hyperplasia. Interestingly, PKCζ-catalyzed Ser-9 phosphorylation and inactivation of GSK-3β and not loss of wild type APC protein accounted for β-catenin accumulation and nuclear translocation in either strain. In vitro studies with Wnt2b and Wnt5a further validated the interplay between the Wnt/β-catenin and NF-κB pathways, respectively. When WT or KO mice were treated with nanoparticle-encapsulated siRNA to β-catenin (si-β-Cat, almost complete loss of nuclear β-catenin coincided with concomitant decreases in CD44 and crypt hyperplasia without defects in NF-κB signaling. si-β-Cat treatment to Apc(Min/+ mice attenuated CR-induced increases in β-catenin and CD44 that halted the growth of mutated crypts without affecting NF-κB signaling. The predominant β-catenin-induced crypt proliferation was further validated in a Castaneus strain (B6

  18. 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

  19. Stromal Clues in Endometrial Carcinoma: Loss of Expression of β-Catenin, Epithelial-Mesenchymal Transition Regulators, and Estrogen-Progesterone Receptor.

    Science.gov (United States)

    Senol, Serkan; Sayar, Ilyas; Ceyran, Ayse B; Ibiloglu, Ibrahim; Akalin, Ibrahim; Firat, Ugur; Kosemetin, Duygu; Engin Zerk, Pinar; Aydin, Abdullah

    2016-05-01

    Epithelial-stroma interactions in the endometrium are known to be responsible for physiological functions and emergence of several pathologic lesions. Periglandular stromal cells act on endometrial cells in a paracrine manner through sex hormones. In this study, we immunohistochemically evaluated the expression of epithelial-mesenchymal transition regulators (SNAIL/SLUG, TWIST, ZEB1), adhesion molecules (β-catenin and E-cadhenin), estrogen (ER)-progesterone (PR) receptor and their correlation with each other in 30 benign, 148 hyperplastic (EH), and 101 endometrioid-type endometrial carcinoma (EC) endometria. In the epithelial component, loss of expression in E-cadherin, ER and PR, and overexpression of TWIST and ZEB1 were significantly higher in EC than in EH (P<0.01). In the periglandular stromal component, β-catenin and SNAIL/SLUG expression were significantly higher in normal endometrium and simple without atypical EH compared with complex atypical EH and EC (P<0.01). In addition, periglandular stromal TWIST expression was significantly higher in EH group compared with EC (P<0.05). There was significantly negative correlation between β-catenin and ER, TWIST and ER, and TWIST and PR in hyperplastic and carcinomatous glandular epithelium, whereas there was a significantly positive correlation between β-catenin and SNAIL-SLUG, β-catenin and TWIST, β-catenin and ER, β-catenin and PR, SNAIL-SLUG and ER, SNAIL-SLUG and PR, TWIST and ER, TWIST and PR, in periglandular/cancer-associated stromal cells (P<0.01). In conclusion, the pattern of positive and negative correlations in the expression of epithelial-mesenchymal transition regulators (SNAIL-SLUG and TWIST), sex hormone receptors (ER and PR), and β-catenin between ECs and hyperplasia, as well as between epithelium and stroma herein, is suggestive of a significant role for these proteins and their underlying molecular processes in the development of endometrial carcinomas.

  20. 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

  1. A study of RUNX3, E-cadherin and β-catenin in CagA-positive Helicobacter pylori associated chronic gastritis in Saudi patients.

    Science.gov (United States)

    Wagih, H M; El-Ageery, S M; Alghaithy, A A

    2015-04-01

    H. pylori is the most important risk factor for gastric carcinoma. CagA-positive H. pylori is associated with an increased risk for gastric cancer compared with negative strains. RUNX3 is a tumor suppressor gene, which is related to the genesis of gastric cancer. β-catenin is integrated with E-cadherin in the cell membrane, and aberrant expression of the complex was reported in gastric carcinoma. Aim of this paper is to determine of the relation between RUNX3, E-cadherin and β-catenin in chronic gastritis associated with cagA-positive H. pylori infection. Retrospective study was done on formalin fixed paraffin embedded gastric biopsies blocks of 90 patients diagnosed as H. pylori associated chronic gastritis. H. pylori was detected using modified Giemsa stain. Nested PCR was used for detection of cagA, reverse transcription-PCR for detection of RUNX3 and immunohistochemistry for detection of E-cadherin and β-catenin. Fifty percent of cases were found to be cagA positive. CagA was significantly associated with the intensity of mononuclear inflammation, the intensity of neutrophilic inflammation, the degree of mucosal atrophy and loss of RUNX3 but not with the density of H. pylori, intestinal metaplasia, E-cadherin or β-catenin. There was significant relation between loss of RUNX3 and increasing density of H. pylori, intensity of neutrophilic inflammation, mucosal atrophy and intestinal metaplasia. RUNX3 was found to be significantly correlated with E-cadherin but not with β-catenin. E-cadherin showed decreased expression in 36.7% of biopsies while, β-catenin was decreased in 33% of biopsies. Loss of RUNX3, E-cadherin and β-catenin was considered early events in the cascade of gastric carcinoma development. Loss of RUNX3 but neither E-cadherin nor β-catenin was related to cagA positive H. pylori strains.

  2. APC/β-catenin-rich complexes at membrane protrusions regulate mammary tumor cell migration and mesenchymal morphology

    International Nuclear Information System (INIS)

    Odenwald, Matthew A; Prosperi, Jenifer R; Goss, Kathleen H

    2013-01-01

    The APC tumor suppressor is mutated or downregulated in many tumor types, and is prominently localized to punctate clusters at protrusion tips in migratory cells, such as in astrocytes where it has been implicated in directed cell motility. Although APC loss is considered an initiating event in colorectal cancer, for example, it is less clear what role APC plays in tumor cell motility and whether loss of APC might be an important promoter of tumor progression in addition to initiation. The localization of APC and β-catenin was analyzed in multiple cell lines, including non-transformed epithelial lines treated with a proteasome inhibitor or TGFβ to induce an epithelial-to-mesenchymal transition (EMT), as well as several breast cancer lines, by immunofluorescence. APC expression was knocked down in 4T07 mammary tumor cells using lentiviral-mediated delivery of APC-specific short-hairpin (sh) RNAs, and assessed using quantitative (q) reverse-transcriptase (RT)-PCR and western blotting. Tumor cell motility was analyzed by performing wound-filling assays, and morphology via immunofluorescence (IF) and phase-contrast microscopy. Additionally, proliferation was measured using BrdU incorporation, and TCF reporter assays were performed to determine β-catenin/TCF-mediated transcriptional activity. APC/β-catenin-rich complexes were observed at protrusion ends of migratory epithelial cells treated with a proteasome inhibitor or when EMT has been induced and in tumor cells with a mesenchymal, spindle-like morphology. 4T07 tumor cells with reduced APC levels were significantly less motile and had a more rounded morphology; yet, they did not differ significantly in proliferation or β-catenin/TCF transcriptional activity. Furthermore, we found that APC/β-catenin-rich complexes at protrusion ends were dependent upon an intact microtubule cytoskeleton. These findings indicate that membrane protrusions with APC/β-catenin-containing puncta control the migratory potential and

  3. 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

  4. 14-3-3σ regulates β-catenin-mediated mouse embryonic stem cell proliferation by sequestering GSK-3β.

    Directory of Open Access Journals (Sweden)

    Tzu-Ching Chang

    Full Text Available Pluripotent embryonic stem cells are considered to be an unlimited cell source for tissue regeneration and cell-based therapy. Investigating the molecular mechanism underlying the regulation of embryonic stem cell expansion is thus important. 14-3-3 proteins are implicated in controlling cell division, signaling transduction and survival by interacting with various regulatory proteins. However, the function of 14-3-3 in embryonic stem cell proliferation remains unclear.In this study, we show that all seven 14-3-3 isoforms were detected in mouse embryonic stem cells. Retinoid acid suppressed selectively the expression of 14-3-3σ isoform. Knockdown of 14-3-3σ with siRNA reduced embryonic stem cell proliferation, while only 14-3-3σ transfection increased cell growth and partially rescued retinoid acid-induced growth arrest. Since the growth-enhancing action of 14-3-3σ was abrogated by β-catenin knockdown, we investigated the influence of 14-3-3σ overexpression on β-catenin/GSK-3β. 14-3-3σ bound GSK-3β and increased GSK-3β phosphorylation in a PI-3K/Akt-dependent manner. It disrupted β-catenin binding by the multiprotein destruction complex. 14-3-3σ overexpression attenuated β-catenin phosphorylation and rescued the decline of β-catenin induced by retinoid acid. Furthermore, 14-3-3σ enhanced Wnt3a-induced β-catenin level and GSK-3β phosphorylation. DKK, an inhibitor of Wnt signaling, abolished Wnt3a-induced effect but did not interfere GSK-3β/14-3-3σ binding.Our findings show for the first time that 14-3-3σ plays an important role in regulating mouse embryonic stem cell proliferation by binding and sequestering phosphorylated GSK-3β and enhancing Wnt-signaled GSK-3β inactivation. 14-3-3σ is a novel target for embryonic stem cell expansion.

  5. 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

  6. APC/β-catenin-rich complexes at membrane protrusions regulate mammary tumor cell migration and mesenchymal morphology

    Science.gov (United States)

    2013-01-01

    Background The APC tumor suppressor is mutated or downregulated in many tumor types, and is prominently localized to punctate clusters at protrusion tips in migratory cells, such as in astrocytes where it has been implicated in directed cell motility. Although APC loss is considered an initiating event in colorectal cancer, for example, it is less clear what role APC plays in tumor cell motility and whether loss of APC might be an important promoter of tumor progression in addition to initiation. Methods The localization of APC and β-catenin was analyzed in multiple cell lines, including non-transformed epithelial lines treated with a proteasome inhibitor or TGFβ to induce an epithelial-to-mesenchymal transition (EMT), as well as several breast cancer lines, by immunofluorescence. APC expression was knocked down in 4T07 mammary tumor cells using lentiviral-mediated delivery of APC-specific short-hairpin (sh) RNAs, and assessed using quantitative (q) reverse-transcriptase (RT)-PCR and western blotting. Tumor cell motility was analyzed by performing wound-filling assays, and morphology via immunofluorescence (IF) and phase-contrast microscopy. Additionally, proliferation was measured using BrdU incorporation, and TCF reporter assays were performed to determine β-catenin/TCF-mediated transcriptional activity. Results APC/β-catenin-rich complexes were observed at protrusion ends of migratory epithelial cells treated with a proteasome inhibitor or when EMT has been induced and in tumor cells with a mesenchymal, spindle-like morphology. 4T07 tumor cells with reduced APC levels were significantly less motile and had a more rounded morphology; yet, they did not differ significantly in proliferation or β-catenin/TCF transcriptional activity. Furthermore, we found that APC/β-catenin-rich complexes at protrusion ends were dependent upon an intact microtubule cytoskeleton. Conclusions These findings indicate that membrane protrusions with APC/β-catenin-containing puncta

  7. 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.

  8. Transiently Active Wnt/β-Catenin Signaling Is Not Required but Must Be Silenced for Stem Cell Function during Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Malea M. Murphy

    2014-09-01

    Full Text Available Adult muscle’s exceptional capacity for regeneration is mediated by muscle stem cells, termed satellite cells. As with many stem cells, Wnt/β-catenin signaling has been proposed to be critical in satellite cells during regeneration. Using new genetic reagents, we explicitly test in vivo whether Wnt/β-catenin signaling is necessary and sufficient within satellite cells and their derivatives for regeneration. We find that signaling is transiently active in transit-amplifying myoblasts, but is not required for regeneration or satellite cell self-renewal. Instead, downregulation of transiently activated β-catenin is important to limit the regenerative response, as continuous regeneration is deleterious. Wnt/β-catenin activation in adult satellite cells may simply be a vestige of their developmental lineage, in which β-catenin signaling is critical for fetal myogenesis. In the adult, surprisingly, we show that it is not activation but rather silencing of Wnt/β-catenin signaling that is important for muscle regeneration.

  9. 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.

  10. β-Catenin destruction complex-independent regulation of Hippo–YAP signaling by APC in intestinal tumorigenesis

    Science.gov (United States)

    Cai, Jing; Maitra, Anirban; Anders, Robert A.; Taketo, Makoto M.; Pan, Duojia

    2015-01-01

    Mutations in Adenomatous polyposis coli (APC) underlie familial adenomatous polyposis (FAP), an inherited cancer syndrome characterized by the widespread development of colorectal polyps. APC is best known as a scaffold protein in the β-catenin destruction complex, whose activity is antagonized by canonical Wnt signaling. Whether other effector pathways mediate APC's tumor suppressor function is less clear. Here we report that activation of YAP, the downstream effector of the Hippo signaling pathway, is a general hallmark of tubular adenomas from FAP patients. We show that APC functions as a scaffold protein that facilitates the Hippo kinase cascade by interacting with Sav1 and Lats1. Consistent with the molecular link between APC and the Hippo signaling pathway, genetic analysis reveals that YAP is absolutely required for the development of APC-deficient adenomas. These findings establish Hippo–YAP signaling as a critical effector pathway downstream from APC, independent from its involvement in the β-catenin destruction complex. PMID:26193883

  11. Role for β-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.

    2008-01-01

    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 β-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-κB-dependent TLR2 signaling in epithelial cells. These data suggest that β-catenin and homeobox genes play an important and conserved role in innate immune defense. PMID:18981407

  12. 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.

  13. 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.

  14. Polycyclic aromatic hydrocarbons disrupt axial development in sea urchin embryos through a β-catenin dependent pathway

    International Nuclear Information System (INIS)

    Pillai, Murali C.; Vines, Carol A.; Wikramanayake, Athula H.; Cherr, Gary

    2003-01-01

    Sea urchin (Lytechinus anemesis) embryos were used as an experimental system to investigate the mechanisms of the developmental toxicity of creosote, one of the most widely used wood preserving chemicals, as well as some of its polycyclic aromatic hydrocarbon (PAH) constituents (phenanthrene, fluoranthene, fluorene, pyrene and quinoline). Data suggest that creosote and PAHs affect axial development and patterning in sea urchin embryos by disrupting the regulation of β-catenin, a crucial transcriptional co-activator of specific target genes in the Wnt/wg signaling pathway. When ciliated blastula stage embryos were exposed to these compounds, they developed into exogastrulae with completely evaginated archentera, demonstrating that these chemicals disrupt axial development and patterning. This response occurred in a dose-dependent fashion, with the EC 50 of creosote for complete exogastrulation being 1.57 ppm, while the EC 50 s of the PAHs ranged from 0.41 ppm (2.0 μM) to 4.33 ppm (33.5 μM). Morphologically, the exogastrulae that developed from embryos exposed to creosote and PAHs appeared to be identical to those that resulted from exposure to lithium chloride, a classical agent known to induce vegetalization and exogastrulation in sea urchin embryos. Immunological studies using antibodies against β-catenin, a multi-functional protein known to be involved in cell-cell adhesion and cell fate specification during embryonic development, revealed high levels of nuclear accumulation of β-catenin by cells of creosote- and PAH-exposed embryos, irrespective of their positions in the developing embryo. Dissociated embryonic cells cultured in the presence of these agents rapidly responded in a similar fashion. Since β-catenin accumulation occurs in nuclei of several types of cancer cells, it is possible this may be a general mechanism by which PAHs affect a variety of different cell types

  15. Different effects of resveratrol on early and late passage mesenchymal stem cells through β-catenin regulation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Dong Suk; Choi, Yoorim; Choi, Seong Mi [Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul (Korea, Republic of); Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul (Korea, Republic of); Park, Kwang Hwan [Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Jin Woo, E-mail: ljwos@yuhs.ac [Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul (Korea, Republic of); Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul (Korea, Republic of)

    2015-11-27

    Resveratrol is a sirtuin 1 (SIRT1) activator and can function as an anti-inflammatory and antioxidant factor. In mesenchymal stem cells (MSCs), resveratrol enhances the proliferation and differentiation potential and has an anti-aging effect. However, contradictory effects of resveratrol on MSC cultures have been reported. In this study, we found that resveratrol had different effects on MSC cultures according to their cell passage and SIRT1 expression. Resveratrol enhanced the self-renewal potential and multipotency of early passage MSCs, but accelerated cellular senescence of late passage MSCs. In early passage MSCs expressing SIRT1, resveratrol decreased ERK and GSK-3β phosphorylation, suppressing β-catenin activity. In contrast, in late passage MSCs, which did not express SIRT1, resveratrol increased ERK and GSK-3β phosphorylation, activating β-catenin. We confirmed that SIRT1-deficient early passage MSCs treated with resveratrol lost their self-renewal potential and multipotency, and became senescent due to increased β-catenin activity. Sustained treatment with resveratrol at early passages maintained the self-renewal potential and multipotency of MSCs up to passage 10. Our findings suggest that resveratrol can be effectively applied to early passage MSC cultures, whereas parameters such as cell passage and SIRT1 expression must be taken into consideration before applying resveratrol to late passage MSCs. - Highlights: • Resveratrol enhances self-renewal potential and multipotency of early passage MSCs. • Resveratrol accelerates the cellular senescence of late passage MSCs. • The effects of resveratrol on MSCs are dependent on the presence of SIRT1. • SIRT1 modulates ERK/GSK-3β/β-catenin signaling. • Sustained resveratrol treatment maintains MSC stemness up to P10.

  16. Immunohistochemical investigation of cell cycle and apoptosis regulators (Survivin, β-Catenin, P53, Caspase 3 in canine appendicular osteosarcoma

    Directory of Open Access Journals (Sweden)

    Bongiovanni Laura

    2012-06-01

    Full Text Available Abstract Background Osteosarcoma (OSA represents the most common canine primary bone tumour. Despite several pathways have been investigated so far, few molecules have been identified as prognostic tools or potential therapeutic targets, and there is still the need to find out molecular pathways with specific influence over OSA progression to facilitate earlier prognosis and treatment. Aims of the present study were to evaluate the immunohistochemical pattern and levels of expression of a panel of molecules (survivin, β-catenin, caspase 3 -inactive and active forms- and p53 involved in cell cycle and apoptosis regulation in canine OSA samples, known to be of interest in the study also of human OSA, and to detect specific relations among them and with histological tumour grade, disease free interval (DFI and overall survival (OS. Results Nuclear β-catenin immunostaining was detected in normal osteoblasts adjacent to the tumour, and in 47% of the cases. Cytoplasmic and/or membranous immunostaining were also observed. Nuclear survivin and p53 positive cells were found in all cases. Moderate/high cytoplasmic β-catenin expression (≥10% positive cells was significantly associated with the development of metastasis (P = 0.014; moderate/high nuclear p53 expression (≥10% positive cells was significantly associated with moderate/high histological grade (P = 0.017 and shorter OS (P = 0.049. Moderate/high nuclear survivin expression (≥15% positive cells showed a tendency toward a longer OS (P = 0,088. Conclusions The present results confirmed p53 as negative prognostic marker, while suggested survivin as a potential positive prognostic indicator, rather than indicative of a poor prognosis. The detection of nuclear β-catenin immunostaining in normal osteoblasts and the absent/low expression in most of the OSAs, suggested that this pathway could not play a major role in oncogenic transformation of canine osteoblasts. Further studies

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

    Science.gov (United States)

    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

  18. Spatiotemporal Expression of Wnt/β-catenin Signaling during Morphogenesis and Odontogenesis of Deciduous Molar in Miniature Pig.

    Science.gov (United States)

    Wu, Xiaoshan; Li, Yan; Wang, Fu; Hu, Lei; Li, Yang; Wang, Jinsong; Zhang, Chunmei; Wang, Songlin

    2017-01-01

    The canonical Wnt/β-catenin signaling pathway has been shown to play essential roles in tooth initiation and early tooth development. However, the role of Wnt/β-catenin signaling in cusp patterning and crown calcification in large mammals are largely unknown. In our previous study, miniature pigs were used as the animal model due to the similarity of tooth anatomy and replacement pattern between miniature pig and human. Dynamic gene expression of third deciduous molar (DM3) in miniature pig at early stages was profiled using microarray method and expression of Wnt genes was significantly correlate with odontogenesis. In the present study, dynamic expression patterns of Wnt/β-catenin signaling genes of DM3 at cap, early bell and late bell (secretory) stage were identified. We found that Lef1 and Axin2 were expressed in the enamel knot and underlying mesenchyme regions. Meanwhile, Dkk1 was expressed in the peripheral and lower parts of dental papilla, thus forming the potential Wnt signaling gradient. We also found that β-Catenin , Axin2 and Lef1 were expressed strongly in undifferentiated cells of the inner enamel epithelium (IEE), but weakly in differentiated ameloblasts. Furthermore, we found that both Wnt signaling read-out gene Lef1 and the inhibitor Dkk1 were co-expressed in the pre-odontoblasts. In conclusion, the spatiotemporal distribution and potential gradient of Wnt signaling may contribute to cusp patterning and crown calcification. These data may yield insight into future study of precise control of crown morphogenesis and regeneration in large mammals.

  19. Nuclear organization in the spinal cord depends on motor neuron lamination orchestrated by catenin and afadin function

    OpenAIRE

    Dewitz, C.; Pimpinella, S.; Hackel, P.; Akalin, A.; Jessell, T.M.; Zampieri, N.

    2018-01-01

    Motor neurons in the spinal cord are found grouped in nuclear structures termed pools, whose position is precisely orchestrated during development. Despite the emerging role of pool organization in the assembly of spinal circuits, little is known about the morphogenetic programs underlying the patterning of motor neuron subtypes. We applied three-dimensional analysis of motor neuron position to reveal the roles and contributions of cell adhesive function by inactivating N-cadherin, catenin, a...

  20. WNT7A/β-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer.

    Science.gov (United States)

    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.

  1. WNT7A/?-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer

    OpenAIRE

    King, Mandy L.; Lindberg, Mallory E.; Stodden, Genna R.; Okuda, Hiroshi; Ebers, Steven D.; Johnson, Alyssa; Montag, Anthony; Lengyel, Ernst; MacLean, James A.; Hayashi, Kanako

    2014-01-01

    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/?-catenin...

  2. Prenatal cadmium exposure dysregulates sonic hedgehog and Wnt/β-catenin signaling in the thymus resulting in altered thymocyte development

    International Nuclear Information System (INIS)

    Hanson, Miranda L.; Brundage, Kathleen M.; Schafer, Rosana; Tou, Janet C.; Barnett, John B.

    2010-01-01

    Cadmium (Cd) is both an environmental pollutant and a component of cigarette smoke. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports in the literature of immunomodulatory effects of prenatal exposure to Cd. The sonic hedgehog (Shh) and Wnt/β-catenin pathways are required for thymocyte maturation. Several studies have demonstrated that Cd exposure affects these pathways in different organ systems. This study was designed to investigate the effect of prenatal Cd exposure on thymocyte development, and to determine if these effects were linked to dysregulation of Shh and Wnt/β-catenin pathways. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose (10 ppm) of Cd throughout pregnancy and effects on the thymus were assessed on the day of birth. Thymocyte phenotype was determined by flow cytometry. A Gli:luciferase reporter cell line was used to measure Shh signaling. Transcription of target genes and translation of key components of both signaling pathways were assessed using real-time RT-PCR and western blot, respectively. Prenatal Cd exposure increased the number of CD4 + cells and a subpopulation of double-negative cells (DN; CD4 - CD8 - ), DN4 (CD44 - CD25 - ). Shh and Wnt/β-catenin signaling were both decreased in the thymus. Target genes of Shh (Patched1 and Gli1) and Wnt/β-catenin (c-fos, and c-myc) were affected differentially among thymocyte subpopulations. These findings suggest that prenatal exposure to Cd dysregulates two signaling pathways in the thymus, resulting in altered thymocyte development.

  3. Hydrostatic Pressure Regulates MicroRNA Expression Levels in Osteoarthritic Chondrocyte Cultures via the Wnt/β-Catenin Pathway

    Directory of Open Access Journals (Sweden)

    Sara Cheleschi

    2017-01-01

    Full Text Available Mechanical loading and hydrostatic pressure (HP regulate chondrocytes’ metabolism; however, how mechanical stimulation acts remain unclear. MicroRNAs (miRNAs play an important role in cartilage homeostasis, mechanotransduction, and in the pathogenesis of osteoarthritis (OA. This study investigated the effects of a cyclic HP (1–5 MPa, in both normal and OA human chondrocytes, on the expression of miR-27a/b, miR-140, miR-146a/b, and miR-365, and of their target genes (MMP-13, ADAMTS-5, IGFBP-5, and HDAC-4. Furthermore, we assessed the possible involvement of Wnt/β-catenin pathway in response to HP. Chondrocytes were exposed to HP for 3h and the evaluations were performed immediately after pressurization, and following 12, 24, and 48 h. Total RNA was extracted and used for real-time PCR. β-catenin was detected by Western blotting analysis and immunofluorescence. In OA chondrocytes, HP induced a significant increase (p < 0.01 of the expression levels of miR-27a/b, miR-140, and miR-146a, and a significant reduction (p < 0.01 of miR-365 at all analyzed time points. MMP-13, ADAMTS-5, and HDAC-4 were significantly downregulated following HP, while no significant modification was found for IGFBP-5. β-catenin levels were significantly increased (p < 0.001 in OA chondrocytes at basal conditions and significantly reduced (p < 0.01 by HP. Pressurization did not cause any significant modification in normal cells. In conclusion, in OA chondrocytes, HP restores the expression levels of some miRNAs, downregulates MMP-13, ADAMTS-5, and HDAC-4, and modulates the Wnt/β-catenin pathway activation.

  4. Salinomycin repressed the epithelial–mesenchymal transition of epithelial ovarian cancer cells via downregulating Wnt/β-catenin pathway

    Directory of Open Access Journals (Sweden)

    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

  5. 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

  6. AV-65, a novel Wnt/β-catenin signal inhibitor, successfully suppresses progression of multiple myeloma in a mouse model

    International Nuclear Information System (INIS)

    Yao, H; Ashihara, E; Strovel, J W; Nakagawa, Y; Kuroda, J; Nagao, R; Tanaka, R; Yokota, A; Takeuchi, M; Hayashi, Y; Shimazaki, C; Taniwaki, M; Strand, K; Padia, J; Hirai, H; Kimura, S; Maekawa, T

    2011-01-01

    Multiple myeloma (MM) is a malignant neoplasm of plasma cells. Although new molecular targeting agents against MM have been developed based on the better understanding of the underlying pathogenesis, MM still remains an incurable disease. We previously demonstrated that β-catenin, a downstream effector in the Wnt pathway, is a potential target in MM using RNA interference in an in vivo experimental mouse model. In this study, we have screened a library of more than 100 000 small-molecule chemical compounds for novel Wnt/β-catenin signaling inhibitors using a high-throughput transcriptional screening technology. We identified AV-65, which diminished β-catenin protein levels and T-cell factor transcriptional activity. AV-65 then decreased c-myc, cyclin D1 and survivin expression, resulting in the inhibition of MM cell proliferation through the apoptotic pathway. AV-65 treatment prolonged the survival of MM-bearing mice. These findings indicate that this compound represents a novel and attractive therapeutic agent against MM. This study also illustrates the potential of high-throughput transcriptional screening to identify candidates for anticancer drug discovery

  7. 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.