scholarly journals Canonical Wnt Signaling Is Critical to Estrogen-Mediated Uterine Growth

2004 ◽  
Vol 18 (12) ◽  
pp. 3035-3049 ◽  
Author(s):  
Xiaonan Hou ◽  
Yi Tan ◽  
Meiling Li ◽  
Sudhansu K. Dey ◽  
Sanjoy K. Das
Keyword(s):  
Wnt Signaling ◽  
Biological Effects ◽  
Canonical Wnt Signaling ◽  
Mouse Uterus ◽  
Independent Manner ◽  
Uterine Epithelial Cell ◽  
Uterine Growth ◽  
Early Effects ◽  
Canonical Wnt

Abstract Major biological effects of estrogen in the uterus are thought to be primarily mediated by nuclear estrogen receptors, ERα and ERβ. We show here that estrogen in an ER-independent manner rapidly up-regulates the expression of Wnt4 and Wnt5a of the Wnt family and frizzled-2 of the Wnt receptor family in the mouse uterus. One of the mechanisms by which Wnts mediate canonical signaling involves stabilization of intracellular β-catenin. We observed that estrogen treatment prompts nuclear localization of active β-catenin in the uterine epithelium. We also found that adenovirus mediated in vivo delivery of SFRP-2, a Wnt antagonist, down-regulates estrogen-dependent β-catenin activity without affecting some of the early effects (water imbibition and angiogenic markers) and inhibits uterine epithelial cell growth, suggesting that canonical Wnt signaling is critical to estrogen-induced uterine growth. Our present results provide evidence for a novel role of estrogen that targets early Wnt/β-catenin signaling in an ER-independent manner to regulate the late uterine growth response that is ER dependent.

Abstract 1457: IGFBP-4-Mediated Wnt Inhibition is Required for Cardiac Myogenesis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Weidong Zhu ◽  
Ichiro Shiojima ◽  
Li Zhi ◽  
Hiroyuki Ikeda ◽  
Masashi Yoshida ◽  
...  
Keyword(s):  
Growth Factor ◽  
Wnt Signaling ◽  
Heart Diseases ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cardiomyocyte Differentiation ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

Insulin-like growth factor-binding proteins (IGFBPs) bind to and modulate the actions of insulin-like growth factors (IGFs). Although some of the effects of IGFBPs appear to be independent of IGFs, the precise mechanisms of IGF-independent actions of IGFBPs are largely unknown. In this study we demonstrate that IGFBP-4 is a novel cardiogenic growth factor. IGFBP-4 enhanced cardiomyocyte differentiation of P19CL6 embryonal carcinoma cells and embryonic stem (ES) cells in vitro. Conversely, siRNA-mediated knockdown of IGFBP-4 in P19CL6 cells or ES cells attenuated cardiomyocyte differentiation, and morpholino-mediated knockdown of IGFBP-4 in Xenopus embryos resulted in severe cardiac defects and complete absence of the heart in extreme cases. We also demonstrate that the cardiogenic effect of IGFBP-4 was independent of its IGF-binding activity but was mediated by the inhibitory effect on canonical Wnt signaling. IGFBP-4 physically interacted with a Wnt receptor Frizzled 8 (Frz8) and a Wnt co-receptor low-density lipoprotein receptor-related protein 6 (LRP6), and inhibited the binding of Wnt3A to Frz8 and LRP6. Moreover, the cardiogenic defects induced by IGFBP-4 knockdown both in vitro and in vivo was rescued by simultaneous inhibition of canonical Wnt signaling. Thus, IGFBP-4 is an inhibitor of the canonical Wnt signaling, and Wnt inhibition by IGFBP-4 is required for cardiogenesis. The present study provides a molecular link between IGF signaling and Wnt signaling, and suggests that IGFBP-4 may be a novel therapeutic target for heart diseases.

Expression of Wnt-3a in Myeloma Cells Inhibits the Osteolytic Phenotype In-Vivo.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3420-3420
Author(s):  
Ya-Wei Qiang ◽  
Shmuel Yaccoby ◽  
John D. Shaughnessy
Keyword(s):  
Bone Resorption ◽  
Wnt Signaling ◽  
Myeloma Cell ◽  
Beta Catenin ◽  
Canonical Wnt Signaling ◽  
Myeloma Cell Line ◽  
Myeloma Cells ◽  
Canonical Wnt

Wnt signaling is a highly conserved signal transduction pathway involved in embryonic development. Inappropriate canonical Wnt signaling resulting in beta-catenin stabilization, is associated with several types of human cancers. Multiple myeloma plasma cells express Wnt receptors, Wnt ligands and soluble Wnt inhibitors. Wnt signaling is central to osteoblast and osteoclasts development and secretion of Wnt signaling inhibitors by myeloma cells is thought to contribute to the osteolytic phenotype seen in this disease and prostate cancer. While it is now clear that MM cells can signal through both canonical and non-canonical mechanisms, there are conflicting data as to the direct role of Wnt signaling in myeloma cell biology. Others have shown that Wnts cause proliferation of myeloma cells; while we have shown that canonical Wnts cause morphological changes and migration, but not cell proliferation. To further elucidate the role of canonical Wnt signaling in myeloma and myeloma bone disease we used limiting dilutions in the presence of G418 to create two independent stable clones of the myeloma cell line NCI-H929 expressing Wnt-3A (H929/W3A), which is not expressed in myeloma, and an empty vector (H929/EV). Because Wnt antibodies are not available we cloned Wnt-3A as a fusion protein with hemagglutinin (HA). Western blots against HA revealed a positive band of the expected size only in the H929/W3A clones. GST-E-cadherin binding assay and Western blot analysis revealed elevated levels of total and free beta-catenin in H929/W3A relative to H929/EV, however, there this was not associated with increased growth or proliferation by MTT assay. To determine the in-vivo growth characteristics and effects on bone resorption of Wnt-3A producing cells, we transplanted the lines into a human bone implanted the flank of SCID mice. Tumor growth rate as determined by increased production of human immunoglobulin in mice serum was significantly slower in the Wnt-3A transfected cells relative to controls (P < .05). Loss of bone mineral density (BMD) of the implanted bones engrafted with H929/W3A cells was lower than in bones engrafted with H929/EV cells (P < .05). Reduced tumor burden and BMD loss was also visualized on x-ray radiographs. Taken together these data indicate that all factors promoting bone resorption produced by or elicited by the myeloma cell line H929 are subordinate to canonical Wnt signaling and that prevention of bone destruction may help control myeloma progression.

AML Survival and In Vivo Progression Is Dependent On β-Catenin Signaling.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2398-2398
Author(s):  
Elena K Siapati ◽  
Magda Papadaki ◽  
Zoi Kozaou ◽  
Erasmia Rouka ◽  
Evridiki Michali ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Wnt Signaling Pathway ◽  
Canonical Wnt Signaling ◽  
Down Regulation ◽  
Canonical Wnt

Abstract Abstract 2398 Poster Board II-375 B-catenin is the central effector molecule of the canonical wnt signaling pathway which governs cell fate and differentiation during embryogenesis as well as self-renewal of hematopoietic stem cells. Deregulation of the pathway has been observed in various malignancies including myeloid leukemias where over-expression of β-catenin is an independent adverse prognostic factor. In the present study we examined the functional outcome of stable β-catenin down-regulation through lentivirus-mediated expression of short hairpin RNA (shRNA). Reduction of the β-catenin levels in AML cell lines and patient samples diminished their in vitro proliferation ability without significantly affecting cell viability. In order to study the role of β-catenin in vivo, we transplanted leukemic cell lines with control or reduced levels of β-catenin in NOD/SCID animals and analyzed the engraftment levels in the bone marrow. We observed that while the immediate homing of the cells was not affected by the β-catenin levels, the bone marrow engraftment was directly dependent on its levels. Subsequent examination of bone marrow sections revealed that the reduced engraftment was partly due to the inability of the cells with lower β-catenin levels to dock to the endosteal niches, a finding that was confirmed in competitive repopulation assays with untransduced cells. When we examined the expression levels of adhesion molecules and integrins in engrafted cells in vivo, we observed a significant down-regulation of CD44 expression, a molecule that participates in the interaction of HSCs with the niche. Gene expression analysis of the components of the wnt signaling pathway showed that the pathway is subject to tight transcriptional regulation with minor expression deviations. We did, however, observe an up-regulation in components that participate in the non-canonical wnt signaling pathways such as the WNT5B ligand. Ongoing experiments in normal cord blood CD34+ cells will determine the in vivo role of β-catenin signaling in normal hematopoietic progenitors. In conclusion, our study showed that β-catenin comprises an integral part in the development and progression of AML in vivo, indicating that manipulation of the wnt pathway may hold a therapeutic potential in the management of AML. Disclosures: No relevant conflicts of interest to declare.

scholarly journals EHMT2 epigenetically suppresses Wnt signaling and is a potential target in embryonal rhabdomyosarcoma

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ananya Pal ◽  
Jia Yu Leung ◽  
Gareth Chin Khye Ang ◽  
Vinay Kumar Rao ◽  
Luca Pignata ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Myogenic Differentiation ◽  
Embryonal Rhabdomyosarcoma ◽  
Differentiation Therapy ◽  
Canonical Wnt Signaling ◽  
Therapeutic Modalities ◽  
Xenograft Models ◽  
Canonical Wnt

Wnt signaling is downregulated in embryonal rhabdomyosarcoma (ERMS) and contributes to the block of differentiation. Epigenetic mechanisms leading to its suppression are unknown and could pave the way toward novel therapeutic modalities. We demonstrate that EHMT2 suppresses canonical Wnt signaling by activating expression of the Wnt antagonist DKK1. Inhibition of EHMT2 expression or activity in human ERMS cell lines reduced DKK1 expression and elevated canonical Wnt signaling resulting in myogenic differentiation in vitro and in mouse xenograft models in vivo. Mechanistically, EHMT2 impacted Sp1 and p300 enrichment at the DKK1 promoter. The reduced tumor growth upon EHMT2 deficiency was reversed by recombinant DKK1 or LGK974, which also inhibits Wnt signaling. Consistently, among 13 drugs targeting chromatin modifiers, EHMT2 inhibitors were highly effective in reducing ERMS cell viability. Our study demonstrates that ERMS cells are vulnerable to EHMT2 inhibitors and suggest that targeting the EHMT2-DKK1-β-catenin node holds promise for differentiation therapy.

Exosome Mediated Wnt-Signaling Augments Side Population In Aggressive Lymphoma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3010-3010
Author(s):  
Raphael Koch ◽  
Martin Demant ◽  
Thiha Aung ◽  
Annemarie Guentsch ◽  
Nina Diering ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
B Cell ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Side Population ◽  
B Cell Lymphoma ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

Abstract Introduction Patients with aggressive B-cell lymphoma are treated in curative intention. However, some patients experience fatal relapse, originating from refractory lymphoma cells with the capacity for clonogenic regrowth. We here addressed repopulation capacity of lymphoma cell subpopulations and the mechanisms regulating the populational composition in the growing tumor. Material & Methods We identified side population (SP) cells in diffuse large B-cell lymphoma cell lines and patient samples with the DNA-binding dye Hoechst33342, analyzed clonogenicity in vitro and in vivo and screened for differentially expressed genes and DNA-methylation patterns. A GFP-containing lentiviral vector construct was used to keep track of side population cells cultured among mixed cultures of SP and nonSP cells. Manipulation of canonical wnt-signaling was performed by lentiviral sh-RNA constructs as well as pharmacological tankyrase-inhibition by XAV-939. In vitro data were supported by in vivo experiments using a chorioallantoic membrane-assay. Results Colony assays and suspension cultures of sorted SP and nonSP cells revealed restriction of clonogenic potential to the SP cell population as well as resurgence of nonSP cells from purified SP cell progenitors, while mixed culture assays using a GFP-vector construct tracing the SP vs. nonSP-population revealed homeostasis between the two populations, showing both SP and nonSP cells contributing to either cell compartment. SP cells show enhanced canonical wnt-signaling and increased exosomal secretion of wnt3a. Suppression of canonical wnt-signaling resulted in reduced clonogenicity. Exosome stimulation of DLBCL cell lines resulted in increased clonogenicity, stabilization of beta catenin and enhanced TOP/FOP activity. Conclusion Here we show that tumor cells reversibly switch between states of autonomous and non-autonomous clonogenicity, and that such transitions are regulated by exosome-mediated wnt signaling. Disclosures: No relevant conflicts of interest to declare.

scholarly journals In vivo tracing of canonical Wnt signaling inXenopustadpoles by means of an inducible transgenic reporter tool

FEBS Letters ◽  
2005 ◽  
Vol 580 (2) ◽  
pp. 393-398 ◽  
Author(s):  
Tinneke Denayer ◽  
Frans Van Roy ◽  
Kris Vleminckx
Keyword(s):  
Wnt Signaling ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

scholarly journals Deregulation of the histone H3K9 di-methylation landscape suppresses canonical Wnt signaling in embryonal rhabdomyosarcoma

2020 ◽  
Author(s):  
Ananya Pal ◽  
Jia Yu Leung ◽  
Gareth Chin Khye Ang ◽  
Vinay Kumar Rao ◽  
Luca Pignata ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Myogenic Differentiation ◽  
Wnt Signaling Pathway ◽  
Embryonal Rhabdomyosarcoma ◽  
Dependent Manner ◽  
Canonical Wnt Signaling ◽  
Therapeutic Modalities ◽  
Canonical Wnt

AbstractThe Wnt signaling pathway is down-regulated in embryonal rhabdomyosarcoma (ERMS) and contributes to the block of myogenic differentiation. Epigenetic mechanisms leading to its suppression are unknown and could pave the way towards novel therapeutic modalities. In this study, we demonstrate that the H3K9 lysine methyltransferase G9a suppresses canonical Wnt signaling by activating expression of the Wnt antagonist DKK1. Inhibition of G9a expression or activity reduced DKK1 expression and elevated canonical Wnt signaling resulting in myogenic differentiation in vitro and in vivo. Mechanistically, G9a impacted Sp1 and p300 enrichment at the DKK1 promoter in a methylation-dependent manner. The reduced tumor growth upon G9a deficiency was reversed by recombinant DKK1 or LGK974, which also inhibits Wnt signaling. Consistently, among thirteen drugs targeting chromatin modifiers, G9a inhibitors were highly effective in reducing ERMS cell viability. Together, our study demonstrates that ERMS cells are vulnerable to G9a inhibitors and suggest that targeting the G9a-DKK1-β-catenin node holds promise for differentiation therapy.

scholarly journals R-spondin 3 deletion favors Erk phosphorylation to enhance Wnt signaling and bone formation

2021 ◽  
Author(s):  
Kenichi Nagano ◽  
Kei Yamana ◽  
Hiroaki Saito ◽  
Riku Kiviranta ◽  
Ana Clara Pedroni ◽  
...  
Keyword(s):  
Bone Density ◽  
Bone Formation ◽  
Bone Mass ◽  
Wnt Signaling ◽  
Erk Signaling ◽  
Canonical Wnt Signaling ◽  
Erk Phosphorylation ◽  
High Bone ◽  
Canonical Wnt

Abstract Activation of Wnt signaling leads to high bone density. The R-spondin family of four secreted glycoproteins (Rspo1-4) amplifies Wnt signaling. In humans, RSPO3 variants are strongly associated with bone density, but how RSPO3 affects skeletal homeostasis is not fully understood. Here we show that in mice Rspo3 haplo-insufficiency or its targeted deletion in osteoprogenitors lead to an increase in bone formation and bone mass. Contrary to expectations, Rspo3 haplo-insufficiency results in canonical Wnt signaling activation. Using mouse embryonic fibroblasts we show that Rspo3 deficiency leads to activation of Erk signaling, stabilizing β-catenin. Furthermore, Rspo3 haplo-insufficiency impairs Dkk1 efficacy in blocking canonical Wnt signaling and prevents the in vivo inhibition of bone formation and bone mass induced by osteoblast-targeted expression of Dkk1. We conclude that Rspo3 haplo-insufficiency/deficiency boosts canonical Wnt signaling by activating Erk signaling and impairing Dkk1’s inhibitory activity, which in turn lead to increased bone formation and bone mass.

scholarly journals Wnt-inducible Lrp6-APEX2 Interacting Proteins Identify ESCRT Machinery and Trk-Fused Gene as Components of the Wnt Signaling Pathway

2020 ◽  
Author(s):  
Gabriele Colozza ◽  
Yasaman Jami-Alahmadi ◽  
Alyssa Dsouza ◽  
Nydia Tejeda-Muñoz ◽  
Lauren V. Albrecht ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Secretory Pathway ◽  
Wnt Signaling Pathway ◽  
Canonical Wnt Signaling ◽  
Labeling Approach ◽  
Canonical Wnt ◽  
Fused Gene ◽  
Multivesicular Endosomes

AbstractThe canonical Wnt signaling pathway serves as a hub connecting diverse cellular physiological processes, such as β-catenin signaling, differentiation, growth, protein stability, macropinocytosis, and nutrient acquisition in lysosomes. We have proposed that sequestration of β-catenin destruction complex components in multivesicular bodies (MVBs) is required for sustained canonical Wnt signaling. In this study, we investigated the events that follow activation of the canonical Wnt receptor Lrp6 using an APEX2-mediated proximity labeling approach. The Wnt co-receptor Lrp6 was fused to APEX2 and used to biotinylate targets that are recruited near the receptor during Wnt signaling at different time periods. Lrp6 proximity targets were identified by mass spectrometry, and revealed that many components of the ESCRT (Endocytic Sorting Components Required for Transport) machinery interacted with Lrp6 within 5 minutes of Wnt3a treatment. This supports the proposal of a central role of multivesicular endosomes in canonical Wnt signaling. Interestingly, proteomic analyses identified the Trk-fused gene (TFG), previously known to regulate the cell secretory pathway and to be rearranged in thyroid and lung cancers, as being strongly enriched in the proximity of Lrp6. We provide evidence that TFG specifically co-localized with MVBs after Wnt stimulation. TFG depletion with siRNA, or knock-out with CRISPR/Cas9, significantly reduced Wnt/β-catenin signaling in cell culture. In vivo, studies in the Xenopus system showed that TFG is required for endogenous Wnt-dependent embryonic patterning. The results suggest that the multivesicular endosomal machinery and the novel player TFG have important roles in Wnt signaling.SignificanceWnt/β-catenin signaling is a conserved pathway involved in cell differentiation and in the regulation of many other processes, including cell growth and proliferation, macropinocytosis, and cell metabolism. Endocytosis is required to regulate Wnt signaling, but the precise factors at play are still elusive. Here, we describe a biotin-dependent proximity labeling approach using ascorbate peroxidase-tagged Lrp6, a Wnt co-receptor. Proteomic analysis of biotinylated-enriched targets identified numerous multivesicular endosome proteins that were recruited to the receptor shortly after addition of Wnt protein. Additionally, we identified the protein TFG as one of the strongest interactors with Lrp6. TFG co-localized with Wnt-induced multivesicular endosomes. Xenopus embryo assays revealed that TFG is required in vivo for canonical Wnt signaling.

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