Suppression of Wnt Expression by Increasing PI3K in Rats Cervical Carcinoma by Andaliman (Zanthoxylum acanthopodium)

&lt;b&gt;Background and Objective:&lt;/b&gt; Cervical cancer is the leading cause of death for women in the world and Indonesia. This disease originates from a malignant tumour of squamous epithelial cells caused by infection with the Human Papilloma Virus (HPV). Antioxidants can reduce oxidative stress in and there are plants from Indonesia that have high antioxidants, namely andaliman (&lt;i&gt;Zanthoxylum acanthopodium&lt;/i&gt;). This study aimed to analyze the role of andaliman on PI3K and Wnt signalling in cervical cancer histology. &lt;b&gt;Materials and Methods:&lt;/b&gt; The study includes 5 treatments. The control group (K-), rats cancer model (K+), rats cancer model+the dose is 100 mg/b.wt. of ZAM (P&lt;sub&gt;1&lt;/sub&gt;), rats cancer model+the dose is 200 mg/b.wt. of ZAM (P&lt;sub&gt;2&lt;/sub&gt;) and rats cancer model+the dosage is 400 mg/b.wt. ZAM (P&lt;sub&gt;3&lt;/sub&gt;). On the 30th day after ZAM administration, the rats were dissected for the paraffin block and Wnt and PI3K immunohistochemical staining was prepared. &lt;b&gt;Results:&lt;/b&gt; There was a significant difference between all groups (p<0.001) in Wnt and PI3K expression. The real role of ZAM in cervical cancer tissue was seen at the highest ZAM dose (P&lt;sub&gt;3&lt;/sub&gt;). Irregular mucosal folds and stretched interstitial connective tissue in the K+ group can return to regularity and improve at the P&lt;sub&gt;3&lt;/sub&gt; dose. The administration of ZAM showed a significant difference in cervical tissue after benzopyrene injection. &lt;b&gt;Conclusion:&lt;/b&gt; Andaliman (&lt;i&gt;Zanthoxylum acanthopodium&lt;/i&gt;) extract increases PI3K expression through suppression of Wnt expression. It can be developed therapy molecularly to prevent cell growth into cancer.

α-Klotho released from HK-2 cells inhibits osteogenic differentiation of renal interstitial fibroblasts by inactivating the Wnt-β-catenin pathway

Randall's plaques (RP) are well established as precursor lesions of idiopathic calcium oxalate (CaOx) stones, and the process of biomineralization driven by osteogenic-like cells has been highlighted in RP formation, but the mechanism is poorly understood. Given the inhibitory role of α-Klotho (KL), an aging suppressor protein with high expression in kidneys, in ectopic calcification and the close association between KL gene polymorphisms and urolithiasis susceptibility, we determined the potential role of KL in RP formation. This study found that both soluble KL (s-KL) and transmembrane KL (m-KL) were downregulated, and that s-KL but not m-KL was inversely correlated with upregulation of osteogenic markers in RP tissues. Additionally, s-KL expression was markedly suppressed in human renal interstitial fibroblasts (hRIFs) and slightly suppressed in HK-2 cells after osteogenic induction, intriguingly, which was echoed to the greater osteogenic capability of hRIFs than HK-2 cells. Further investigations showed the inhibitory effect of s-KL on hRIF osteogenic differentiation in vitro and in vivo. Moreover, coculture with recombinant human KL (r-KL) or HK-2 cells suppressed osteogenic differentiation of hRIFs, and this effect was abolished by coculture with KL-silenced HK-2 cells or the β-catenin agonist SKL2001. Mechanistically, s-KL inactivated the Wnt-β-catenin pathway by directly binding to Wnt2 and upregulating SFRP1. Further investigations identified activation of the Wnt-β-catenin pathway and downregulation of SFRP1 and DKK1 in RP tissues. In summary, this study identified s-KL deficiency as a pathological feature of RP and revealed that s-KL released from HK-2 cells inhibited osteogenic differentiation of hRIFs by inactivating the Wnt-β-catenin pathway, not only providing in-depth insight into the role of s-KL in renal interstitial biomineralization but also shedding new light on the interaction of renal tubular epithelial cells with interstitial cells to clarify RP formation.

Dynamic Expression of Transient Receptor Potential Vanilloid-3 and Integrated Signaling with Growth Factor Pathways during Lung Epithelial Wound Repair following Wood Smoke Particle and Other Forms of Lung Cell Injury

Prior studies revealed increased expression of the transient receptor potential vanilloid-3 (TRPV3) ion channel after wood smoke particulate matter (WSPM) treatment of human bronchial epithelial cells (HBECs). TRPV3 attenuated pathologic endoplasmic reticulum stress and cytotoxicity mediated by transient receptor potential ankyrin-1. Here, the basis for how TRPV3 expression is regulated by cell injury and the effects this has on HBEC physiology and WSPM-induced airway remodeling in mice was investigated. TRPV3 mRNA was rapidly increased in HBECs treated with WSPM and after monolayer damage caused by tryptic disruption, scratch wounding, and cell passaging. TRPV3 mRNA abundance varied with time, and stimulated expression occurred independent of new protein synthesis. Overexpression of TRPV3 in HBECs reduced cell migration and wound repair while enhancing cell adhesion. This phenotype correlated with disrupted mRNA expression of ligands of the epidermal growth factor, tumor growth factor-β, and frizzled receptors. Accordingly, delayed wound repair by TRPV3 overexpressing cells was reversed by growth factor supplementation. In normal HBECs, TRPV3 upregulation was triggered by exogenous growth factor supplementation and was attenuated by inhibitors of growth factor receptor signaling. In mice, subacute oropharyngeal instillation with WSPM also promoted TRPV3 mRNA expression and epithelial remodeling, which was attenuated by TRPV3 antagonist pre- and cotreatment. This latter effect may be the consequence of antagonist-induced TRPV3 expression. These findings provide insights into the roles of TRPV3 in lung epithelial cells under basal and dynamic states, as well as highlight potential roles for TRPV3 ligands in modulating epithelial damage/repair. SIGNIFICANCE STATEMENT: Coordinated epithelial repair is essential for the maintenance of the airways, with deficiencies and exaggerated repair associated with adverse consequences to respiratory health. This study shows that TRPV3, an ion channel, is involved in coordinating repair through integrated repair signaling pathways, wherein TRPV3 expression is upregulated immediately after injury and returns to basal levels as cells complete the repair process. TRPV3 may be a novel target for understanding and/or treating conditions in which airway/lung epithelial repair is not properly orchestrated.

Breast milk nutrients driving intestinal epithelial layer maturation via Wnt and Notch signaling: Implications for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an often lethal, inflammatory disease of the preterm intestine. The underdeveloped immune system plays an important role; however, the initial trigger for NEC development is likely a damaged intestinal epithelial layer. We hypothesize that due to incomplete maturation of different epithelial cell lineages, nutrients and bacteria are able to damage the epithelial cells and cause the (immature) inflammatory response, food intolerance and malabsorption seen in NEC. Intestinal organoid research has shown that maturation of intestinal epithelial cell lineages is orchestrated by two key signaling pathways: Wnt and Notch. In NEC, these pathways are dysregulated by hyperactivation of Toll-like-receptor-4. Breastfeeding decreases the risk of developing NEC compared to formula milk. Here, we review the intricate link between breast milk components, Wnt and Notch signaling and intestinal epithelial maturation. We argue that (nutritional) interventions regulating these pathways may decrease the risk of NEC development in preterm infants.

Impact of WNT Pathway Blockade on the Biological Characteristics of Renal Tubular Epithelial Cells Stably Transfected with PAX2

OBJECTIVE

The WNT pathway might be the primary pathway for the regulation of renal development by PAX2. In this study, we aimed to observe the migration and invasion abilities of human tubular epithelial cells stably transfected with PAX2 upon the WNT pathway blockade and to investigate whether the WNT pathway is involved in the regulation of cellular biological activity by PAX2.

METHODS

1. Control cells-PAX2 and control cells+PAX2 groups were formed for monitoring the expression of PAX2 and β-catenin mRNA using RT-qPCR. 2. The PAX2-expressing cells were treated with WIF-1 (5 μg/ml), WIF-1 (10 μg/ml), or WIF-1 (15 μg/ml), and the effect was analyzed by Western blotting analysis after the WNT pathway blockade. 3. The migration and invasion abilities of the PAX2-expressing cells were evaluated using cell-scratch and transwell assays after blocking the WNT pathway.

RESULTS

1. RT-qPCR: The expression of PAX2 and β-catenin increased significantly in the PAX2-expressing cells (P<0.05). 2. Upon treatment with WIF-1, the expression of β-catenin in the PAX2 cells+WIF-1 5 μg/ml group, PAX2 cells+WIF-1 10μg/ml group, and PAX2 cells+WIF-1 15 μg/ml group decreased significantly compared to in the PAX2 cells-WIF-1 group (P<0.05), especially the WIF-1 (15 μg/ml) group (P<0.05). 3. The cell migration rate in the PAX2 cells + WIF-1 (15 μg/ml) group at 18 h was significantly lower than that in the PAX2 cells-WIF-1 group (P<0.05). 3. Transwell assay: the invasion ability in the PAX2 cells+WIF-1 (15 μg/ml) group was lower than that in the PAX2 cells-WIF-1 group (P<0.05).

CONCLUSION

WNT pathway blockade can weaken the migration and invasion abilities of PAX2-expressing cells. Moreover, the WNT pathway was observed to be associated with the regulation of cellular biological activity by PAX2.

Secreted Wnt antagonists in scrub typhus

BACKGROUND

The mechanisms that control local and systemic inflammation in scrub typhus have only been partially elucidated. The wingless (Wnt) signaling pathways are emerging as important regulators of inflammation and infection, but have not been investigated in scrub typhus.

METHODOLOGY/PRINCIPAL FINDINGS

Plasma levels of secreted Wnt antagonists (i.e. DKK-1, sFRP-3, WIF-1 and SOST) were analyzed in patients with scrub typhus (n = 129), patients with similar febrile illness without O. tsutsugamushi infection (n = 31), febrile infectious disease controls, and in healthy controls (n = 31) from the same area of South India, and were correlated to markers of inflammation, immune and endothelial cell activation as well as for their association with organ specific dysfunction and mortality in these patients. We found i) Levels of SOST and in particular sFRP-3 and WIF-1 were markedly increased and DKK-1 decreased in scrub typhus patients at admission to the hospital compared to healthy controls. ii) In recovering scrub typhus patients, SOST, sFRP-3 and WIF-1 decreased and DKK-1 increased. iii) SOST was positively correlated with markers of monocyte/macrophage and endothelial/vascular activation as well as with renal dysfunction and poor outcome iv) Finally, regulation of Wnt pathways by O. tsutsugamushi in vitro in monocytes and ex vivo in mononuclear cells isolated from patients with scrub typhus, as evaluated by gene expression studies available in public repositories, revealed markedly attenuated canonical Wnt signaling.

CONCLUSIONS/SIGNIFICANCE

Our findings suggest that scrub typhus is characterized by attenuated Wnt signaling possibly involving dysregulated levels of several secreted pathway antagonists. The secreted Wnt antagonist SOST was strongly associated with renal dysfunction and poor prognosis in these patients.

A RNA-seq approach for exploring the protective effect of ginkgolide B on glutamate-induced astrocytes injury

ETHNOPHARMACOLOGICAL RELEVANCE

There is substantial experimental evidence to support the view that Ginkgo biloba L. (Ginkgoaceae), a traditional Chinese medicine known to treating stroke, has a protective effect on the central nervous system and significantly improves the cognitive dysfunction caused by disease, including alzheimer disease (AD), vascular dementia, and diabetic encephalopathy. Although a number of studies have reported that ginkgolide B (GB), a diterpenoid lactone compound extracted from Ginkgo biloba leaves, has neuroprotective effects, very little research has been performed to explore its potential pharmacological mechanism on astrocytes under abnormal glutamate (Glu) metabolism in the pathological environment of AD.

AIM OF THE STUDY

We investigated the protective effect and mechanism of GB on Glu-induced astrocytes injury.

METHODS

Astrocytes were randomly divided into the control group, Glu group, GB group, and GB + IWP-4 group.The CCK-8 assay was used to determine relative cell viability in vitro. Furthermore, RNA sequencing (RNA-seq) was performed to assess the preventive effects of GB in the Glu-induced astrocyte model and reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to validate the possible molecular mechanisms. The effects of GB on the Glu transporter and Glu-induced apoptosis of astrocytes were studied by RT-qPCR and western blot.

RESULTS

GB attenuated Glu-induced apoptosis in a concentration-dependent manner, while the Wnt inhibitor IWP-4 reversed the protective effect of GB on astrocytes. The RNA-seq results revealed 4,032 differential gene expression profiles; 3,491 genes were up-regulated, and 543 genes were down-regulated in the GB group compared with the Glu group. Differentially expressed genes involved in a variety of signaling pathways, including the Hippo and Wnt pathways have been associated with the development and progression of AD. RT-qPCR was used to validate 14 key genes, and the results were consistent with the RNA-seq data. IWP-4 inhibited the regulation of GB, disturbed the apoptosis protective effect on astrocytes, and promoted Glu transporter gene and protein expression caused by Glu.

CONCLUSION

Our findings demonstrate that GB may play a protective role in Glu-induced astrocyte injury by regulating the Hippo and Wnt pathways. GB was closely associated with the Wnt pathway by promoting expression of the Glu transporter and inhibiting Glu-induced injury in astrocytes.

Management of Myeloma Bone Lesions

Multiple myeloma (MM) is a B-cell neoplasm characterized by clonal plasma-cell proliferation. The survival and prognosis of this condition have been significantly improved by treatment with active anti-MM drugs such as bortezomib or lenalidomide. Further, the discovery of novel agents has recently paved the way for new areas of investigation. However, MM, including myeloma-related bone diseases, remains fatal. Bone disease or bone destruction in MM is a consequence of skeletal involvement with bone pain, spinal cord compression, and bone fracture resulting from osteolytic lesions. These consequences affect disease outcomes, including patients' quality of life and survival. Several studies have sought to better understand MM bone disease (MBD) through the classification of its molecular mechanisms, including osteoclast activation and osteoblast inhibition. Bisphosphonates and the receptor activator of the nuclear factor-kappa B (NF-κB) ligand (RANKL) inhibitor, denosumab, prevent skeletal-related events in MM. In addition, several other bone-targeting agents, including bone-anabolic drugs, are currently used in preclinical and early clinical evaluations. This review summarizes the current knowledge of the pathogenesis of MBD and discusses novel agents that appear very promising and will soon enter clinical development.

Blockers of Wnt3a, Wnt10a, or β-Catenin Prevent Chemotherapy-Induced Neuropathic Pain In Vivo

Although chemotherapy is a key cancer treatment, many chemotherapeutic drugs produce chronic neuropathic pain, called chemotherapy-induced neuropathic pain (CINP), which is a dose-limiting adverse effect. To date, there is no medicine that prevents CINP in cancer patients and survivors. We determined whether blockers of the canonical Wnt signaling pathway prevent CINP. Neuropathic pain was induced by intraperitoneal injection of paclitaxel (PAC) on four alternate days in male Sprague-Dawley rats or male Axin2-LacZ knock-in mice. XAV-939, LGK-974, and iCRT14, Wnt/β-catenin blockers, were administered intraperitoneally as a single or multiple doses before or after injury. Mechanical allodynia, phosphoproteome profiling, Wnt ligands, and inflammatory mediators were measured by von Frey filament, phosphoproteomics, reverse transcription-polymerase chain reaction, and Western blot analysis. Localization of β-catenin was determined by immunohistochemical analysis in the dorsal root ganglia (DRGs) in rats and human. Our phosphoproteome profiling of CINP rats revealed significant phosphorylation changes in Wnt signaling components. Importantly, repeated systemic injections of XAV-939 or LGK-974 prevented the development of CINP in rats. In addition, XAV-939, LGK-974, and iCRT14 ameliorated CINP. PAC increased Wnt3a and Wnt10a, activated β-catenin in DRG, and increased monocyte chemoattractant protein-1 and interleukin-1β in DRG. PAC also upregulated rAxin2 in mice. Furthermore, β-catenin was expressed in neurons, including calcitonin gene-related protein-expressing neurons and satellite cells in rat and human DRG. In conclusion, chemotherapy increases Wnt3a, Wnt10a, and β-catenin in DRG and their pharmacological blockers prevent and ameliorate CINP, suggesting a target for the prevention and treatment of CINP.

Mouse embryonic stem cells self-organize into trunk-like structures with neural tube and somites

Post-implantation embryogenesis is a highly dynamic process comprising multiple lineage decisions and morphogenetic changes that are inaccessible to deep analysis in vivo. We found that pluripotent mouse embryonic stem cells (mESCs) form aggregates that upon embedding in an extracellular matrix compound induce the formation of highly organized "trunk-like structures" (TLSs) comprising the neural tube and somites. Comparative single-cell RNA sequencing analysis confirmed that this process is highly analogous to mouse development and follows the same stepwise gene-regulatory program. Tbx6 knockout TLSs developed additional neural tubes mirroring the embryonic mutant phenotype, and chemical modulation could induce excess somite formation. TLSs thus reveal an advanced level of self-organization and provide a powerful platform for investigating post-implantation embryogenesis in a dish.

The involvement of noncanonical Wnt signaling in cancers

Wnt signaling is one of the key cascades regulating normal tissue development and has been tightly associated with cancer. The Wnt signaling can be subdivided into two categories: canonical & noncanonical. Noncanonical Wnt signaling pathways mainly include Wnt/PCP (planar cell polarity) signaling and Wnt-cGMP (cyclic guanosine monophosphate) /Ca2+ signaling. It has been well studied by previous researches that noncanonical Wnt signaling regulates multiple cell functions including proliferation, differentiation, adhesion, polarity, motility, and migration. The aberrant activation or inhibition of noncanonical Wnt signaling is crucial in cancer progression, exerting both oncogenic and tumor-suppressive effects. Recent studies show the involvement of noncanonical Wnt in regulating cancer cell invasion, metastasis, metabolism, and inflammation. Here, we review current insights into novel components of non-canonical signalings and describe their involvement in various cancer types. We also summarize recent biological and clinical discoveries that outline non-canonical Wnt signaling in tumorigenesis. Finally, we provide an overview of current strategies to target non-canonical Wnt signaling in cancer and challenges that are associated with such approaches.

Specific induction and long-term maintenance of high purity ventricular cardiomyocytes from human induced pluripotent stem cells

Currently, cardiomyocyte (CM) differentiation methods require a purification step after CM induction to ensure the high purity of the cell population. Here we show an improved human CM differentiation protocol with which high-purity ventricular-type CMs can be obtained and maintained without any CM purification process. We induced and collected a mesodermal cell population (platelet-derived growth factor receptor-α (PDGFRα)-positive cells) that can respond to CM differentiation cues, and then stimulated CM differentiation by means of Wnt inhibition. This method reproducibly generated CMs with purities above 95% in several human pluripotent stem cell lines. Furthermore, these CM populations were maintained in culture at such high purity without any further CM purification step for over 200 days. The majority of these CMs (>95%) exhibited a ventricular-like phenotype with a tendency to structural and electrophysiological maturation, including T-tubule-like structure formation and the ability to respond to QT prolongation drugs. This is a simple and valuable method to stably generate CM populations suitable for cardiac toxicology testing, disease modeling and regenerative medicine.

WNT11-Conditioned Medium Promotes Angiogenesis through the Activation of Non-Canonical WNT-PKC-JNK Signaling Pathway

BACKGROUND

We demonstrated that the transduction of Wnt11 into mesenchymal stem cells (MSCs) (MSCWnt11) promotes these cells differentiation into cardiac phenotypes. In the present study, we investigated the paracrine effects of MSCWnt11 on cardiac function and angiogenesis.

METHODS AND RESULTS

Conditioned medium was collected from MSCWnt11 (CdMWnt11) and their control cells (CdMGFP). CdMWnt11, especially obtained from MSCWnt11 exposed to hypoxia, significantly promoted human umbilical vein endothelial cells (HUVECs) migration and increased capillary-like tube (CLT) formation, which was blocked by Wnt11 neutralizing antibody. Wnt11 protein was significantly higher in CdMWnt11 compared to that in CdMGFP. Directly treating HUVECs with recombinant Wnt11 protein significantly increased CLT formation, which was abrogated by treating cells with the JNK inhibitor SP600125, as well as the PKC inhibitor Calphostin-C. Moreover, the transfection of Wnt11 to HUVECs (HWnt11) significantly increased CLT formation and HUVEC migration, as well as upregulated p-pan-PKC and p-JNK expression. Injection of CdMWnt11 into the peri-infarct region in a rat acute myocardial infarction (AMI) model significantly improved cardiac function, reduced infarct size, and increased myocardial blood flow and blood vessel density in the ischemic area.

CONCLUSION

Wnt11 released from MSCWnt11 increased angiogenesis and improved cardiac function via non-canonical Wnt-PKC-JNK dependent pathways.

In Situ Fucosylation of the Wnt Co-receptor LRP6 Increases Its Endocytosis and Reduces Wnt/β-Catenin Signaling

Wnt/β-catenin signaling regulates critical, context-dependent transcription in numerous physiological events. Among the well-documented mechanisms affecting Wnt/β-catenin activity, modification of N-glycans by L-fucose is the newest and the least understood. Using a combination of Chinese hamster ovary cell mutants with different fucosylation levels and cell-surface fucose editing (in situ fucosylation [ISF]), we report that α(1-3)-fucosylation of N-acetylglucosamine (GlcNAc) in the Galβ(1-4)-GlcNAc sequences of complex N-glycans modulates Wnt/β-catenin activity by regulating the endocytosis of low-density lipoprotein receptor-related protein 6 (LRP6). Pulse-chase experiments reveal that ISF elevates endocytosis of lipid-raft-localized LRP6, leading to the suppression of Wnt/β-catenin signaling. Remarkably, Wnt activity decreased by ISF is fully reversed by the exogenously added fucose. The combined data show that in situ cell-surface fucosylation can be exploited to regulate a specific signaling pathway via endocytosis promoted by a fucose-binding protein, thereby linking glycosylation of a receptor with its intracellular signaling.

New insights into the core Hippo signaling and biological macromolecules interactions in the biology of solid tumors

As an evolutionarily conserved pathway, Hippo signaling pathway impacts different pathology and physiology processes such as wound healing, tissue repair/size and regeneration. When some components of Hippo signaling dysregulated, it affects cancer cells proliferation. Moreover, the relation Hippo pathway with other signaling including Wnt, TGFβ, Notch, and EGFR signaling leaves effect on the proliferation of cancer cells. Utilizing a number of therapeutic approaches, such as siRNAs and long noncoding RNA (lncRNA) to prevent cancer cells through the targeting of Hippo pathways, can provide new insights into cancer target therapy. The purpose of present review, first of all, is to demonstrate the importance of Hippo signaling and its relation with other signaling pathways in cancer. It also tries to demonstrate targeting Hippo signaling progress in cancer therapy.

Targeting Tumorigenicity of Breast Cancer Stem Cells Using SAHA/Wnt-b Catenin Antagonist Loaded Onto Protein Corona of Gold Nanoparticles

BACKGROUND

Among various theories for the origin of cancer, the "stemness phenotype model" suggests a dynamic feature for tumor cells in which non-cancer stem cells (non-CSCs) can inter-convert to CSCs. Differentiation with histone-deacetylase inhibitor, vorinostat (SAHA), can induce stem cells to differentiate as well as enforces non-CSCs to reprogram to CSCs. To avoid this undesirable effect, one can block the Wnt-βcatenin pathway. Thus, a dual delivery system of SAHA and a Wnt-βcatenin blocker will be beneficial in the induction of differentiation of CSCs. Protein corona (PC) formation in nanoparticle has a biologic milieu, and despite all problematic properties, it can be employed as a medium for dual loading of the drugs.

MATERIALS AND METHODS

We prepared sphere gold nanoparticles (GNPs) with human plasma protein corona loaded with SAHA as differentiating agent and PKF118-310 (PKF) as a Wnt-βcatenin antagonist. The MCF7 breast cancer stem cells were treated with NPs and the viability and differentiation were evaluated by Western blotting and sphere formation assay.

RESULTS

We found that both drugs loaded onto corona-capped GNPs had significant cytotoxicity in comparison to bare GNP-corona. Data demonstrated an increase in stem cell population and upregulation of mesenchymal marker, Snail by SAHA-loaded GNPs treatment; however, the combination of PKF loaded GNPs along with SAHA-loaded GNPs resulted in a reduction of stem cell populations and Snail marker. We have shown that in MCF7 and its CSCs simultaneous treatment with SAHA and PKF118-310 induced differentiation and inhibition of Snail induction.

CONCLUSION

Our study reveals the PC-coated GNPs as a biocompatible career for both hydrophilic (PKF) and hydrophobic (SAHA) agents which can decrease breast cancer stem cell populations along with reduced stemness state regression.

Progenitors oppositely polarize WNT activators and inhibitors to orchestrate tissue development

To spatially co-exist and differentially specify fates within developing tissues, morphogenetic cues must be correctly positioned and interpreted. Here, we investigate mouse hair follicle development to understand how morphogens operate within closely spaced, fate-diverging progenitors. Coupling transcriptomics with genetics, we show that emerging hair progenitors produce both WNTs and WNT inhibitors. Surprisingly, however, instead of generating a negative feedback loop, the signals oppositely polarize, establishing sharp boundaries and consequently a short-range morphogen gradient that we show is essential for three-dimensional pattern formation. By establishing a morphogen gradient at the cellular level, signals become constrained. The progenitor preserves its WNT signaling identity and maintains WNT signaling with underlying mesenchymal neighbors, while its overlying epithelial cells become WNT-restricted. The outcome guarantees emergence of adjacent distinct cell types to pattern the tissue.

High-Throughput Drug Screening Identifies a Potent Wnt Inhibitor that Promotes Airway Basal Stem Cell Homeostasis

Mechanisms underpinning airway epithelial homeostatic maintenance and ways to prevent its dysregulation remain elusive. Herein, we identify that β-catenin phosphorylated at Y489 (p-β-cateninY489) emerges during human squamous lung cancer progression. This led us to develop a model of airway basal stem cell (ABSC) hyperproliferation by driving Wnt/β-catenin signaling, resulting in a morphology that resembles premalignant lesions and loss of ciliated cell differentiation. To identify small molecules that could reverse this process, we performed a high-throughput drug screen for inhibitors of Wnt/β-catenin signaling. Our studies unveil Wnt inhibitor compound 1 (WIC1), which suppresses T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) activity, reduces ABSC proliferation, induces ciliated cell differentiation, and decreases nuclear p-β-cateninY489. Collectively, our work elucidates a dysregulated Wnt/p-β-cateninY489 axis in lung premalignancy that can be modeled in vitro and identifies a Wnt/β-catenin inhibitor that promotes airway homeostasis. WIC1 may therefore serve as a tool compound in regenerative medicine studies with implications for restoring normal airway homeostasis after injury.

An Underlying Mechanism of Dual Wnt Inhibition and AMPK Activation: Mitochondrial Uncouplers Masquerading as Wnt Inhibitors

The importance of upregulated Wnt signaling in colorectal cancers led to efforts to develop inhibitors that target β-catenin in this pathway. We now report that several "Wnt inhibitors" that allegedly target β-catenin actually function as mitochondrial proton uncouplers that independently activate AMPK and concomitantly inhibit Wnt signaling. As expected for a process in which mitochondrial uncoupling diminishes ATP production, a mitochondrial proton uncoupler, FCCP, and a glucose metabolic inhibitor, 2-DG, activated AMPK and inhibited Wnt signaling. Also consistent with these findings, a well-known "Wnt inhibitor", FH535, functioned as a proton uncoupler, and in support of this finding, the N-methylated analog, 2,5-dichloro-N-methyl-N-(2-methyl-4-nitrophenyl)benzenesulfonamide (FH535-M), was inactive as an uncoupler and Wnt inhibitor. Apart from suggesting an opportunity to develop dual Wnt inhibitors and AMPK activators, these findings provide a cautionary tale that claims for Wnt inhibition alone require scrutiny as possible mitochondrial proton uncouplers or inhibitors of the electron transport chain.

Lanatoside C Induces G2/M Cell Cycle Arrest and Suppresses Cancer Cell Growth by Attenuating MAPK, Wnt, JAK-STAT, and PI3K/AKT/mTOR Signaling Pathways

Cardiac glycosides (CGs) are a diverse family of naturally derived compounds having a steroid and glycone moiety in their structures. CG molecules inhibit the α-subunit of ubiquitous transmembrane protein Na⁺/K⁺-ATPase and are clinically approved for the treatment of cardiovascular diseases. Recently, the CGs were found to exhibit selective cytotoxic effects against cancer cells, raising interest in their use as anti-cancer molecules. In this current study, we explored the underlying mechanism responsible for the anti-cancer activity of Lanatoside C against breast (MCF-7), lung (A549), and liver (HepG2) cancer cell lines. Using Real-time PCR, western blot, and immunofluorescence studies, we observed that (i) Lanatoside C inhibited cell proliferation and induced apoptosis in cell-specific and dose-dependent manner only in cancer cell lines; (ii) Lanatoside C exerts its anti-cancer activity by arresting the G2/M phase of cell cycle by blocking MAPK/Wnt/PAM signaling pathways; (iii) it induces apoptosis by inducing DNA damage and inhibiting PI3K/AKT/mTOR signaling pathways; and finally, (iv) molecular docking analysis shows significant evidence on the binding sites of Lanatoside C with various key signaling proteins ranging from cell survival to cell death. Our studies provide a novel molecular insight of anti-cancer activities of Lanatoside C in human cancer cells.

Sostdc1: A soluble BMP and Wnt antagonist that is induced by the interaction between myeloma cells and osteoblast lineage cells

Multiple myeloma (MM) is characterised by destructive lytic bone disease, caused by induction of bone resorption and impaired bone formation. Our understanding of the molecular mechanisms responsible for osteoblast suppression, are limited. Using the 5T2MM murine model of MM we have previously shown that suppression of the activity of a known inhibitor of bone formation Dikkopf-1 (Dkk1) prevents the development of lytic bone disease. Here we have demonstrated that another potential inhibitor of bone formation, sclerostin domain containing 1 (Sostdc1) is expressed at low levels in MM and osteoblast lineage cells when these cells are grown separately in cell culture but its expression is significantly induced in both cell types when these cells are in contact. The distribution of Sostdc1 staining in bones infiltrated with 5TGM1 myeloma cells in vivo suggested its presence in both myeloma and osteoblast lineage populations when in close proximity. We have also shown that recombinant Sostdc1 inhibits both bone morphogenic proteins (BMP2 and 7) and Wnt signalling in primary osteoblasts and suppresses differentiation of these cells. Together, these findings suggest that Sostdc1 expression in 5TGM1-infiltrated bones as a result of the interaction between myeloma and osteoblast lineage populations, could result in suppression of osteoblast differentiation.

Regulation of WNT5A and WNT11 during MSC in vitro chondrogenesis: WNT inhibition lowers BMP and hedgehog activity, and reduces hypertrophy

Re-directing mesenchymal stromal cell (MSC) chondrogenesis towards a non-hypertrophic articular chondrocyte-(AC)-like phenotype is important for improving articular cartilage neogenesis to enhance clinical cartilage repair strategies. This study is the first to demonstrate that high levels of non-canonical WNT5A followed by WNT11 and LEF1 discriminated MSC chondrogenesis from AC re-differentiation. Moreover, β-catenin seemed incompletely silenced in differentiating MSCs, which altogether suggested a role for WNT signaling in hypertrophic MSC differentiation. WNT inhibition with the small molecule IWP-2 supported MSC chondrogenesis according to elevated proteoglycan deposition and reduced the characteristic upregulation of BMP4, BMP7 and their target ID1, as well as IHH and its target GLI1 observed during endochondral differentiation. Along with the pro-hypertrophic transcription factor MEF2C, multiple hypertrophic downstream targets including IBSP and alkaline phosphatase activity were reduced by IWP-2, demonstrating that WNT activity drives BMP and hedgehog upregulation, and MSC hypertrophy. WNT inhibition almost matched the strong anti-hypertrophic capacity of pulsed parathyroid hormone-related protein application, and both outperformed suppression of BMP signaling with dorsomorphin, which also reduced cartilage matrix deposition. Yet, hypertrophic marker expression under IWP-2 remained above AC level, and in vivo mineralization and ectopic bone formation were reduced but not eliminated. Overall, the strong anti-hypertrophic effects of IWP-2 involved inhibition but not silencing of pro-hypertrophic BMP and IHH pathways, and more advanced silencing of WNT activity as well as combined application of IHH or BMP antagonists should next be considered to install articular cartilage neogenesis from human MSCs.

Mechanisms of action of vitamin D in colon cancer

Colorectal cancer (CRC) is the neoplasia that is most frequently associated with vitamin D deficiency in epidemiological and observational studies in terms of incidence and mortality. Many mechanistic studies show that the active vitamin D metabolite (1α,25-dihydroxyvitamin D₃ or calcitriol) inhibits proliferation and promotes epithelial differentiation of human colon carcinoma cell lines that express vitamin D receptor (VDR) via the regulation of a high number of genes. A key action underlining this effect is the multilevel inhibition of the Wnt/β-catenin signaling pathway, whose abnormal activation in colon epithelial cells initiates and promotes CRC. Recently, our group has shown that calcitriol modulates gene expression and inhibits protumoral properties of patient-derived colon cancer-associated fibroblasts (CAFs). Accordingly, high VDR expression in tumor stromal fibroblasts is associated with longer survival of CRC patients. Moreover, many types of immune cells express VDR and are regulated by calcitriol, which probably contributes to its action against CRC. Given the role attributed to the intestinal microbiota in CRC and the finding that it is altered by vitamin D deficiency, an indirect antitumoral effect of calcitriol is also plausible at this level. In summary, calcitriol has an array of potential protective effects against CRC by acting on carcinoma cells, CAFs, immune cells and probably also the gut microbiota.

Hypermethylation of multiple Wnt antagonist genes in gastric neoplasia: Is H pylori infection blasting fuse?

Wnt antagonist genes hypermethylation has been found in several tumors. Accordingly, the events that occur during the progression of adenoma to carcinoma have been characterized and include activation of the Wnt-pathway. Further, gastric adenoma (GA) is a premalignant lesion of gastric adenocarcinoma (GAC). In this paper, we focused our interesting on Wnt signaling path function in the pathogenesis of GAC.We compared the differences between low grade adenoma (LGA), high grade adenoma (HGA), GACs and corresponding normal gastric tissue (NGT). Specific indexes include the pathological characteristics of gastric neoplasia, Helicobacter pylori infection, β-catenin mutation status, and methylation status of Wnt antagonist genes.There was significant difference of β-catenin expression in patient with NGT, LGA, HGA, and GAC, the results respectively were 4.2%, 41.7%, 83.3%, and 91.7%. Only 1 GACs was detected exon 3 of β-catenin mutation. Wnt antagonist genes mRNA expression levels, such as APC, sFRP-1, Wif-1, and Dkk-1, were significantly reduced in GAC. Promoter methylation levels of the 4 genes were significantly elevated in GAC and HGA compared to NGT and LGA. However, there was no significant difference between HGAs and GACs. The β-catenin abnormal expression was correlated with hypermethylation of these 4 genes. Multiple gene concurrent methylation phenomenon was increased from NGTs to GACs; the amount of methylation genes in GACs and HGAs was more than NGTs and LGAs. The more methylation of the above-mentioned genes, the more severity of local inflammation. The infection rate of H pylori was significantly higher in patient with HGA (66.7%, 16/24) and GAC (58.5%, 14/24) than in LGAs (16.7%,4/24) (PHGA-LGA = .024, PGAC-LGA = .032). In addition, the present of H pylori also correlated with the β-catenin abnormal expression and the hypermethylation status of Wnt antagonist genes (P < .001). But other parameters in adenoma cases had no significantly related with infection of H pylori.Hypermethylation of Wnt antagonist genes may have a tight relationship with gastric tumorigenesis. And these genes may increase the incidence of GAC. Additionally, H pylori may have promotion function in GA formation.

Controlled Release of Small Molecules for Cardiac Differentiation of Pluripotent Stem Cells

Induced pluripotent stem cells (iPSCs) have been shown to differentiate to functional cardiomyocytes (CM) with high efficiency through temporally controlled inhibition of the GSK3/Wnt signaling pathways. In this study, we investigated the ability of temporally controlled release of GSK3/Wnt small-molecule inhibitors to drive cardiac differentiation of iPSC without manual intervention. Porous silica particles were loaded with GSK3 inhibitor CHIR99021 or Wnt inhibitor IWP2, and the particles containing IWP2 were coated with 5 wt% poly(lactic-co-glycolic acid) 50:50 to delay release by ∼72 h. iPSCs reprogrammed through mRNA transfection were cultured with these particles up to 30 days. High-performance liquid chromatography suggests a burst release of CHIR99021 within the first 24 h and a delayed release of IWP2 after 72 h. Annexin V/propidium iodide staining did not show a significant effect on apoptosis or necrosis rates. Cultured cells upregulated both early (Nkx 2.5, Isl-1) and late (cTnT, MHC, Cx43) cardiac markers, assayed with a quantitative real-time polymerase chain reaction, and began spontaneous contraction at 3.0 ± 0.6 Hz at 15-21 days after the start of differentiation. CM had clear sarcomeric striations when stained for β-myosin heavy chain, and showed expression and punctate membrane localization of gap junction protein Connexin43. Calcium and voltage-sensitive imaging showed both action potential and calcium transients typical of immature CM. This study showed that the cardiac differentiation of pluripotent stem cells can be directed by porous silica vectors with temporally controlled release of small-molecule inhibitors. These results suggest methods for automating and eliminating variability in manual maintenance of inhibitor concentrations in the differentiation of pluripotent stem cells to CM.

Potent in vivo lung cancer Wnt signaling inhibition via cyclodextrin-LGK974 inclusion complexes

Activation of the Wnt signaling pathway promotes lung cancer progression and contributes to poor patient prognosis. The porcupine inhibitor LGK974, a novel orally bioavailable cancer therapeutic in Phase I clinical trials, induces potent Wnt signaling inhibition and leads to suppressed growth and progression of multiple types of cancers. The clinical use of LGK974, however, is limited in part due to its low solubility and high toxicity in tissues that rely on Wnt signaling for normal homeostasis. Here, we report the use of host-guest chemistry to enhance the solubility and bioavailability of LGK974 in mice through complexation with cyclodextrins (CD). We assessed the effects of these complexes to inhibit Wnt signaling in lung adenocarcinomas that are typically driven by overactive Wnt signaling. 2D ¹H NMR confirmed host-guest complexation of CDs with LGK974. CD:LGK974 complexes significantly decreased the expression of Wnt target genes in lung cancer organoids and in lung cancer allografts in mice. Further, CD:LGK974 complexes increased the bioavailability upon oral administration in mice compared to free LGK974. In a mouse lung cancer allograft model, CD:LGK974 complexes induced potent Wnt signaling inhibition with reduced intestinal toxicity compared to treatment with free drug. Collectively, the development of these complexes enables safer and repeated oral or parenteral administration of Wnt signaling inhibitors, which hold promise for the treatment of multiple types of malignancies.

Secreted Wnt antagonists in leukemia: A road yet to be paved

Wnt signaling has been a topic of research for many years for its diverse and fundamental functions in physiological (such as embryogenesis, organogenesis, proliferation, tissue repair and cellular differentiation) and pathological (carcinogenesis, congenital/genetic diseases, and tissue degeneration) processes. Wnt signaling pathway aberrations are associated with both solid tumors and hematological malignancies. Unregulated Wnt signaling observed in malignancies may be due to a wide spectrum of abnormalities, from mutations in the genes of key players to epigenetic modifications of Wnt antagonists. Of these, Wnt antagonists are gaining significant attention for their potential of being targets for treatment and inhibition of Wnt signaling. In this review, we discuss and summarize the significance of Wnt signaling antagonists in the pathogenesis and treatment of hematological malignancies.

[Neurotrophin-3 enhances the osteogenesis ability of human bone marrow mesenchymal stem cells stimulated by lipopolysaccharide]

Objective To investigate the protective effect of neurotrophin-3 (NT-3) on human bone marrow mesenchymal stem cells (hBMSCs) and its ability to promote the differentiation of hBMSCs into osteoblasts in the inflammatory environment. Methods The cell inflammation model was established by lipopolysaccharide (LPS). The hBMSCs without any stimulation was defined as the inflammatory control group; the hBMSCs stimulated by 100 ng/mL human NT-3 recombinant protein as the NT-3 group; the hBMSCs stimulated by 100 mmol/L pyrvinium pamoate (PP) for 12 hours and then stimulated by 100 ng/mL human NT-3 recombinant protein as the Wnt inhibitor group; the normal cultured hBMSCs as the normal control group. We performed the experiment of osteoblast induction on all groups. CCK-8 assay was used to detect the proliferation of hBMSCs; the fluorescein isothiocyanate labeled annexin V/propidium iodide (Annexin V-FITC/PI) double labeling combined with flow cytometry was used to detect the apoptosis of hBMSCs; ELISA was used to detect the protein levels of runt-related transcription factor 2 (RUNX2) protein and alkaline phosphatase (ALP); and the alizarin red staining experiment was conducted to detect the ability of calcium nodule formation. Results Compared with the inflammatory control group, the proliferative activity of hBMSCs in NT-3 group significantly increased, the apoptosis obviously decreased, and the contents of RUNX2 and ALP, as well as the intensity of alizarin red staining in NT-3 group evidently rose. Compared with the NT-3 group, the proliferative activity of hBMSCs in the Wnt inhibitor group was inhibited, the cell apoptosis was promoted, and the contents of RUNX2 and ALP, as well as the intensity of alizarin red staining in the Wnt inhibitor group were reduced remarkably. Conclusion NT-3 can protect hBMSCs from anti-inflammatory damage and promote the differentiation of hBMSCs into osteoblasts.

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

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.

Inhibition of nuclear Wnt signalling: challenges of an elusive target for cancer therapy

The highly conserved Wnt signalling pathway plays an important role in embryonic development and disease pathogenesis, most notably cancer. The 'canonical' or β-catenin-dependent Wnt signal initiates at the cell plasma membrane with the binding of Wnt proteins to Frizzled:LRP5/LRP6 receptor complexes and is mediated by the translocation of the transcription co-activator protein, β-catenin, into the nucleus. β-Catenin then forms a complex with T-cell factor (TCF)/lymphoid enhancer binding factor (LEF) transcription factors to regulate multiple gene programmes. These programmes play roles in cell proliferation, migration, vasculogenesis, survival and metabolism. Mutations in Wnt signalling pathway components lead to constitutively active Wnt signalling that drives aberrant expression of these programmes and development of cancer. It has been a longstanding and challenging goal to develop therapies that can interfere with the TCF/LEF-β-catenin transcriptional complex. This review will focus on the (i) structural considerations for targeting the TCF/LEF-β-catenin and co-regulatory complexes in the nucleus, (ii) current molecules that directly target TCF/LEF-β-catenin activity and (iii) ideas for targeting newly discovered components of the TCF/LEF-β-catenin complex and/or downstream gene programmes regulated by these complexes.

LINKED ARTICLES

This article is part of a themed section on WNT Signalling: Mechanisms and Therapeutic Opportunities. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.24/issuetoc.

The Transcription Factor Foxg1 Promotes Optic Fissure Closure in the Mouse by Suppressing Wnt8b in the Nasal Optic Stalk

During vertebrate eye morphogenesis, a transient fissure forms at its inferior part, known as the optic fissure. This will gradually close, giving rise to a healthy, spherical optic cup. Failure of the optic fissure to close gives rise to an ocular disorder known as coloboma. During this developmental process, Foxg1 is expressed in the optic neuroepithelium, with highest levels of expression in the nasal optic stalk. Foxg1-/- mutant mice have microphthalmic eyes with a large ventral coloboma. We found Wnt8b expression upregulated in the Foxg1-/- optic stalk and hypothesized that, similar to what is observed in telencephalic development, Foxg1 directs development of the optic neuroepithelium through transcriptional suppression of Wnt8b To test this, we generated Foxg1-/-;Wnt8b-/- double mutants of either sex and found that the morphology of the optic cup and stalk and the closure of the optic fissure were substantially rescued in these embryos. This rescue correlates with restored Pax2 expression in the anterior tip of the optic fissure. In addition, although we do not find evidence implicating altered proliferation in the rescue, we observe a significant increase in apoptotic cell density in Foxg1-/-;Wnt8b-/- double mutants compared with the Foxg1-/- single mutant. Upregulation of Wnt/β-catenin target molecules in the optic cup and stalk may underlie the molecular and morphological defects in the Foxg1-/- mutant. Our results show that proper optic fissure closure relies on Wnt8b suppression by Foxg1 in the nasal optic stalk to maintain balanced apoptosis and Pax2 expression in the nasal and temporal edges of the fissure.SIGNIFICANCE STATEMENT Coloboma is an ocular disorder that may result in a loss of visual acuity and accounts for ∼10% of childhood blindness. It results from errors in the sealing of the optic fissure (OF), a transient structure at the bottom of the eye. Here, we investigate the colobomatous phenotype of the Foxg1-/- mutant mouse. We identify upregulated expression of Wnt8b in the optic stalk of Foxg1-/- mutants before OF closure initiates. Foxg1-/-;Wnt8b-/- double mutants show a substantial rescue of the Foxg1-/- coloboma phenotype, which correlates with a rescue in molecular and cellular defects of Foxg1-/- mutants. Our results unravel a new role of Foxg1 in promoting OF closure providing additional knowledge about the molecules and cellular mechanisms underlying coloboma formation.

Wnt signaling, a novel pathway regulating blood pressure? State of the art review

Recent antihypertensive trials show conflicting results on blood pressure (BP) targets in patient populations with different metabolic profiles, with lowest benefit from tight BP control observed in patients with type 2 diabetes mellitus. This paradox could arise from the heterogeneity of study populations and underscores the importance of precision medicine initiatives towards understanding and treating hypertension. Wnt signaling pathways and genetic variations in its signaling peptides have been recently associated with metabolic syndrome, hypertension and diabetes, generating a breakthrough for advancement of precision medicine in the field of hypertension. We performed a review of PubMed for publications addressing the contributions of Wnt to BP regulation and hypertension. In addition, we performed a manual search of the reference lists for relevant articles, and included unpublished observations from our laboratory. There is emerging evidence for Wnt's role in BP regulation and its involvement in the pathogenesis of hypertension. Wnt signaling has pleiotropic effects on distinct pathways that involve vascular smooth muscle plasticity, and cardiac, renal, and neural physiology. Hypertension is a heterogeneous disease with unique molecular pathways regulating its response to therapy. Recognition of these pathways is a prerequisite to identify novel targets for drug development and personalizing medicine. A review of Wnt signaling reveals its emerging role in BP regulation and as a target for novel drug development that has the potential to transform the therapy of hypertension in specific populations.

WNT antagonists exhibit unique combinatorial antitumor activity with taxanes by potentiating mitotic cell death

The WNT pathway mediates intercellular signaling that regulates cell fate in both normal development and cancer. It is widely appreciated that the WNT pathway is frequently dysregulated in human cancers through a variety of genetic and epigenetic mechanisms. Targets in the WNT pathway are being extensively pursued for the development of new anticancer therapies, and we have advanced two WNT antagonists for clinical development: vantictumab (anti-FZD) and ipafricept (FZD8-Fc). We examined the antitumor efficacy of these WNT antagonists in combination with various chemotherapies in a large set of patient-derived xenograft models. In responsive models, WNT blockade led to profound synergy with taxanes such as paclitaxel, and the combination activity with taxanes was consistently more effective than with other classes of chemotherapy. Taxane monotherapy increased the frequency of cells with active WNT signaling. This selection of WNT-active chemotherapy-resistant tumorigenic cells was prevented by WNT-antagonizing biologics and required sequential dosing of the WNT antagonist followed by the taxane. The WNT antagonists potentiated paclitaxel-mediated mitotic blockade and promoted widespread mitotic cell death. By blocking WNT/β-catenin signaling before mitotic blockade by paclitaxel, we found that this treatment effectively sensitizes cancer stem cells to taxanes. This combination strategy and treatment regimen has been incorporated into ongoing clinical testing for vantictumab and ipafricept.

Age-related increase in Wnt inhibitor causes a senescence-like phenotype in human cardiac stem cells

Aging of cardiac stem/progenitor cells (CSCs) impairs heart regeneration and leads to unsatisfactory outcomes of cell-based therapies. As the precise mechanisms underlying CSC aging remain unclear, the use of therapeutic strategies for elderly patients with heart failure is severely delayed. In this study, we used human cardiosphere-derived cells (CDCs), a subtype of CSC found in the postnatal heart, to identify secreted factor(s) associated with CSC aging. Human CDCs were isolated from heart failure patients of various ages (2-83 years old). Gene expression of key soluble factors was compared between CDCs derived from young and elderly patients. Among these factors, SFRP1, a gene encoding a Wnt antagonist, was significantly up-regulated in CDCs from elderly patients (≥65 years old). sFRP1 levels was increased significantly also in CDCs, whose senescent phenotype was induced by anti-cancer drug treatment. These results suggest the participation of sFRP1 in CSC aging. We show that the administration of recombinant sFRP1 induced cellular senescence in CDCs derived from young patients, as indicated by increased levels of markers such as p16, and a senescence-associated secretory phenotype. In addition, co-administration of recombinant sFRP1 could abrogate the accelerated CDC proliferation induced by Wnt3A. Taken together, our results suggest that canonical Wnt signaling and its antagonist, sFRP1, regulate proliferation of human CSCs. Furthermore, excess sFRP1 in elderly patients causes CSC aging.

Modulating the wnt signaling pathway with small molecules

Wnt signaling is a critical component during embryonic development and also plays an important role in regulating adult tissue homeostasis. Abnormal activation of Wnt signaling has been implicated in many cancers, while reduced activity of Wnt signaling leads to poor wound healing and structural formations. Thus, extensive efforts have been focused on developing small molecules that have potential to either inhibit or activate the pathway, hoping these molecules can offer leads for novel approaches in treating different human diseases. Many small-molecule inhibitors specifically target various elements, such as Frizzled, Disheveled, Porcupine, or Tankyrase, within the Wnt signaling pathways. These small molecules not only have the potential to be further developed as therapeutic reagents, but they may also be used as chemical probes to dissect the underlying mechanism of the Wnt signaling pathways. Therefore, their respective mechanisms and effective dosages are highly pertinent. Aiming to provide an overview of those molecules in a concise, easy-to-use manner, we summarize and organize the current research on them so that it may be helpful for utilization in different studies.

Rational design of DKK3 structure-based small peptides as antagonists of Wnt signaling pathway and in silico evaluation of their efficiency

Dysregulated Wnt signaling pathway is highly associated with the pathogenesis of several human cancers. Dickkopf proteins (DKKs) are thought to inhibit Wnt signaling pathway through binding to lipoprotein receptor-related protein (LRP) 5/6. In this study, based on the 3-dimensional (3D) structure of DKK3 Cys-rich domain 2 (CRD2), we have designed and developed several peptide inhibitors of Wnt signaling pathway. Modeller 9.15 package was used to predict 3D structure of CRD2 based on the Homology modeling (HM) protocol. After refinement and minimization with GalaxyRefine and NOMAD-REF servers, the quality of selected models was evaluated utilizing VADAR, SAVES and ProSA servers. Molecular docking studies as well as literature-based information revealed two distinct boxes located at CRD2 which are actively involved in the DKK3-LRP5/6 interaction. A peptide library was constructed conducting the backrub sequence tolerance scanning protocol in Rosetta3.5 according to the DKK3-LRP5/6 binding sites. Seven tolerated peptides were chosen and their binding affinity and stability were improved by some logical amino acid substitutions. Molecular dynamics (MD) simulations of peptide-LRP5/6 complexes were carried out using GROMACS package. After evaluation of binding free energies, stability, electrostatic potential and some physicochemical properties utilizing computational approaches, three peptides (PEP-I1, PEP-I3 and PEP-II2) demonstrated desirable features. However, all seven improved peptides could sufficiently block the Wnt-binding site of LRP6 in silico. In conclusion, we have designed and improved several small peptides based on the LRP6-binding site of CRD2 of DKK3. These peptides are highly capable of binding to LRP6 in silico, and may prevent the formation of active Wnt-LRP6-Fz complex.

Androgens modify Wnt agonists/antagonists expression balance in dermal papilla cells preventing hair follicle stem cell differentiation in androgenetic alopecia

In androgenetic alopecia, androgens impair dermal papilla-induced hair follicle stem cell (HFSC) differentiation inhibiting Wnt signaling. Wnt agonists/antagonists balance was analyzed after dihydrotestosterone (DHT) stimulation in androgen-sensitive dermal papilla cells (DPC) cultured as spheroids or monolayer. In both culture conditions, DHT stimulation downregulated Wnt5a and Wnt10b mRNA while the Wnt antagonist Dkk-1 was upregulated. Notably, tissue architecture of DPC-spheroids lowers Dkk-1 and enhances Wnt agonists' basal expression; probably contributing to DPC inductivity. The role of Wnt agonists/antagonists as mediators of androgen inhibition of DPC-induced HFSC differentiation was evaluated. Inductive DPC-conditioned medium supplemented with DKK-1 impaired HFSC differentiation mimicking androgens' action. This effect was associated with inactivation of Wnt/β-catenin pathway in differentiating HFSC by both DPC-conditioned media. Moreover, addition of WNT10b to DPC-medium conditioned with DHT, overcame androgen inhibition of HFSC differentiation. Our results identify DKK1 and WNT10b as paracrine factors which modulate the HFSC differentiation inhibition involved in androgen-driven balding.

Concurrent Hypermethylation of SFRP2 and DKK2 Activates the Wnt/β-Catenin Pathway and Is Associated with Poor Prognosis in Patients with Gastric Cancer

Aberrant hypermethylation of Wnt antagonists has been observed in gastric cancer. A number of studies have focused on the hypermethylation of a single Wnt antagonist and its role in regulating the activation of signaling. However, how the Wnt antagonists interacted to regulate the signaling pathway has not been reported. In the present study, we systematically investigated the methylation of some Wnt antagonist genes (SFRP2, SFRP4, SFRP5, DKK1, DKK2, and APC) and their regulatory role in carcinogenesis. We found that aberrant promoter methylation of SFRP2, SFRP4, DKK1, and DKK2 was significantly increased in gastric cancer. Moreover, concurrent hypermethylation of SFRP2 and DKK2 was observed in gastric cancer and this was significantly associated with increased expression of β-catenin, indicating that the joint inactivation of these two genes promoted the activation of the Wnt signaling pathway. Further analysis using a multivariate Cox proportional hazards model showed that DKK2 methylation was an independent prognostic factor for poor overall survival, and the predictive value was markedly enhanced when the combined methylation status of SFRP2 and DKK2 was considered. In addition, the methylation level of SFRP4 and DKK2 was correlated with the patient's age and tumor differentiation, respectively. In conclusion, epigenetic silencing of Wnt antagonists was associated with gastric carcinogenesis, and concurrent hypermethylation of SFRP2 and DKK2 could be a potential marker for a prognosis of poor overall survival.

SRI36160 is a specific inhibitor of Wnt/β-catenin signaling in human pancreatic and colorectal cancer cells

Activation of Wnt/β-catenin signaling is associated with pancreatic and colorectal cancer, among others. To-date, there are no FDA-approved small molecule Wnt/β-catenin inhibitors and many past efforts resulted in compounds with undesirable off-target effects. We recently identified a series of benzimidazole analogs as potent inhibitors of Wnt/β-catenin signaling. Here, we show that the lead compound SRI36160 displayed selective Wnt inhibition and potent antiproliferative activity in pancreatic and colorectal cancer cells. Moreover, SRI36160 had no effect on STAT3 and mTORC1 signaling in pancreatic and colorectal cancer cells, and was not effective in inhibiting proliferation of non-cancerous cells. Our findings suggest that this series of benzimidazole analogs presents a novel approach for the treatment of Wnt-dependent cancers such as colorectal and pancreatic cancer.

Effects of TNF Inhibitors on Parathyroid Hormone and Wnt Signaling Antagonists in Rheumatoid Arthritis

Tumor necrosis factor α inhibitors (TNFi) are the major class of biologic drug used for the treatment of Rheumatoid arthritis (RA). Their effects on inflammation and disease control are well established, but this is not true also for bone metabolism, especially for key factors as parathyroid hormone and Wnt pathway. Those two pathways are gaining importance in the pathogenesis RA bone damage, both systemic and local, but how the new treatment affects them is still largely unknown. We studied 54 RA patients who were starting an anti-TNFα treatment due to the failure of the conventional synthetic disease-modifying antirheumatic drugs. Serum levels of Wnt/βcatenin pathway inhibitors (Dickkopf-related protein 1, Dkk1, and Sclerostin), Parathyroid hormone (PTH), vitamin D, and bone turnover markers were measured at baseline in the morning after fasting and after 6 months of therapy. We found a significant percentage increase in serum PTH (+32 ± 55 %; p = 0.002) and a decrease in Dkk1 mean serum levels (-2.9 ± 12.1; p = 0.05). PTH percentage changes were positively correlated both with C-terminal telopeptide of type I collagen and Dkk1 percentage changes. Sclerostin serum levels showed no significant difference. TNFi treatment provokes in the short term a rise in PTH levels and a decrease in Dkk1 serum levels. The increase of PTH might promote bone resorption and blunt the normalization of Dkk1 serum levels in RA. Those data give a new insight into TNFi metabolic effects on bone and suggest new strategies to achieve better results in terms of prevention of bone erosions and osteoporosis with TNFi treatment in RA.

WNT-C59, a Small-Molecule WNT Inhibitor, Efficiently Induces Anterior Cortex That Includes Cortical Motor Neurons From Human Pluripotent Stem Cells

The recapitulation of human neural development in a controlled, defined manner from pluripotent stem cells (PSCs) has considerable potential for studies of human neural development, circuit formation and function, and the construction of in vitro models of neurological diseases. The inhibition of Wnt signaling, often by the recombinant protein DKK1, is important for the induction of cortical neurons. Here, we report a novel differentiation method using a small-molecule WNT inhibitor, WNT-C59 (C59), to efficiently induce human anterior cortex. We compared two types of small molecules, C59 and XAV939 (XAV), as substitutes for DKK1 to induce cortical neurons from PSCs in serum-free embryoid body-like aggregate culture. DKK1 and XAV inhibited only the canonical pathway of Wnt signaling, whereas C59 inhibited both the canonical and noncanonical pathways. C59 efficiently induced CTIP2+/COUP-TF1- cells, which are characteristic of the cells found in the anterior cortex. In addition, when grafted into the cortex of adult mice, the C59-induced cells showed abundant axonal fiber extension toward the spinal cord. These results raise the possibility of C59 contributing to cell replacement therapy for motor neuron diseases or insults.

SIGNIFICANCE

For a cell therapy against damaged corticospinal tract caused by neurodegenerative diseases or insults, cortical motor neurons are needed. Currently, their induction from pluripotent stem cells is considered very promising; however, an efficient protocol to induce motor neurons is not available. For efficient induction of anterior cortex, where motor neurons are located, various WNT inhibitors were investigated. It was found that one of them could induce anterior cortical cells efficiently. In addition, when grafted into the cortex of adult mice, the induced cells showed more abundant axonal fiber extension toward spinal cord. These results raise the possibility that this inhibitor contributes to a cell-replacement therapy for motor neuron diseases or insults.

Comprehensive Expression of Wnt Signaling Pathway Genes during Development and Maturation of the Mouse Cochlea

BACKGROUND

In the inner ear Wnt signaling is necessary for proliferation, cell fate determination, growth of the cochlear duct, polarized orientation of stereociliary bundles, differentiation of the periotic mesenchyme, and homeostasis of the stria vascularis. In neonatal tissue Wnt signaling can drive proliferation of cells in the sensory region, suggesting that Wnt signaling could be used to regenerate the sensory epithelium in the damaged adult inner ear. Manipulation of Wnt signaling for regeneration will require an understanding of the dynamics of Wnt pathway gene expression in the ear. We present a comprehensive screen for 84 Wnt signaling related genes across four developmental and postnatal time points.

RESULTS

We identified 72 Wnt related genes expressed in the inner ear on embryonic day (E) 12.5, postnatal day (P) 0, P6 and P30. These genes included secreted Wnts, Wnt antagonists, intracellular components of canonical signaling and components of non-canonical signaling/planar cell polarity.

CONCLUSION

A large number of Wnt signaling molecules were dynamically expressed during cochlear development and in the early postnatal period, suggesting complex regulation of Wnt transduction. The data revealed several potential key regulators for further study.

Cotargeting Polo-Like Kinase 1 and the Wnt/β-Catenin Signaling Pathway in Castration-Resistant Prostate Cancer

The Wnt/β-catenin signaling pathway has been identified as one of the predominantly upregulated pathways in castration-resistant prostate cancer (CRPC). However, whether targeting the β-catenin pathway will prove effective as a CRPC treatment remains unknown. Polo-like kinase 1 (Plk1) is a critical regulator in many cell cycle events, and its level is significantly elevated upon castration of mice carrying xenograft prostate tumors. Indeed, inhibition of Plk1 has been shown to inhibit tumor growth in several in vivo studies. Here, we show that Plk1 is a negative regulator of Wnt/β-catenin signaling. Plk1 inhibition or depletion enhances the level of cytosolic and nuclear β-catenin in human prostate cancer cells. Furthermore, inhibition of Wnt/β-catenin signaling significantly potentiates the antineoplastic activity of the Plk1 inhibitor BI2536 in both cultured prostate cancer cells and CRPC xenograft tumors. Mechanistically, axin2, a negative regulator of the β-catenin pathway, serves as a substrate of Plk1, and Plk1 phosphorylation of axin2 facilitates the degradation of β-catenin by enhancing binding between glycogen synthase kinase 3β (GSK3β) and β-catenin. Plk1-phosphorylated axin2 also exhibits resistance to Cdc20-mediated degradation. Overall, this study identifies a novel Plk1-Wnt signaling axis in prostate cancer, offering a promising new therapeutic option to treat CRPC.

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

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

Secreted Frizzled-Related Protein 3 (SFRP3) Is Required for Tumorigenesis of PAX3-FOXO1-Positive Alveolar Rhabdomyosarcoma

PURPOSE

Rhabdomyosarcoma (RMS) is a soft tissue sarcoma associated with the skeletal muscle lineage. Of the two predominant subtypes, known as embryonal (eRMS) and alveolar (aRMS), aRMS has the poorer prognosis, with a five-year survival rate of <50%. The majority of aRMS tumors express the fusion protein PAX3-FOXO1. As PAX3-FOXO1 has proven chemically intractable, this study aims to identify targetable proteins that are downstream from or cooperate with PAX3-FOXO1 to support tumorigenesis.

EXPERIMENTAL DESIGN

Microarray analysis of the transcriptomes of human skeletal muscle myoblasts expressing PAX3-FOXO1 revealed alteration of several Wnt pathway gene members, including secreted frizzled related protein 3 (SFRP3), a secreted Wnt pathway inhibitor. Loss-of-function using shRNAs against SFRP3 was used to interrogate the role of SFRP3 in human aRMS cell lines in vitro and conditional murine xenograft systems in vivo. The combination of SFRP3 genetic suppression and the chemotherapeutic agent vincristine was also examined.

RESULTS

In vitro, suppression of SFRP3 inhibited aRMS cell growth, reduced proliferation accompanied by a G1 arrest and induction of p21, and induced apoptosis. In vivo, doxycycline-inducible suppression of SFRP3 reduced aRMS tumor growth and weight by more than three-fold, in addition to increasing myogenic differentiation and β-catenin signaling. The combination of SFRP3 suppression and vincristine was more effective at reducing aRMS cell growth in vitro than either treatment alone, and ablated tumorigenesis in vivo.

CONCLUSIONS

SFRP3 is necessary for the growth of human aRMS cells both in vitro and in vivo and is a promising new target for investigation in aRMS.

Downregulation of the Wnt inhibitor CXXC5 predicts a better prognosis in acute myeloid leukemia

The gene CXXC5 on 5q31 is frequently deleted in acute myeloid leukemia (AML) with del(5q), suggesting that inactivation of CXXC5 might play a role in leukemogenesis. Here, we investigated the functional and prognostic implications of CXXC5 expression in AML. CXXC5 mRNA was downregulated in AML with MLL rearrangements, t(8;21) and GATA2 mutations. As a mechanism of CXXC5 inactivation, we found evidence for epigenetic silencing by promoter methylation. Patients with CXXC5 expression below the median level had a lower relapse rate (45% vs 59%; P = .007) and a better overall survival (OS, 46% vs 28%; P < .001) and event-free survival (EFS, 36% vs 21%; P < .001) at 5 years, independent of cytogenetic risk groups and known molecular risk factors. In gene-expression profiling, lower CXXC5 expression was associated with upregulation of cell-cycling genes and co-downregulation of genes implicated in leukemogenesis (WT1, GATA2, MLL, DNMT3B, RUNX1). Functional analyses demonstrated CXXC5 to inhibit leukemic cell proliferation and Wnt signaling and to affect the p53-dependent DNA damage response. In conclusion, our data suggest a tumor suppressor function of CXXC5 in AML. Inactivation of CXXC5 is associated with different leukemic pathways and defines an AML subgroup with better outcome.

Resonance assignment and secondary structure determination of full length human Dickkopf 4 (hDkk4), a secreted, disulphide-rich Wnt inhibitor protein

A number of proteins have been shown to modulate canonical Wnt signalling at the cell surface, including members of the Dickkopf (Dkk) family (Baron and Rawadi in J Endocrinol 148:2635-2643, 2007; Cruciat and Niehrs in Cold Spring Harb Perspect Biol 5:a015081, 2013). The Dkk family includes four secreted proteins (Dkk1-4), which are characterised by two highly conserved cysteine-rich regions corresponding to C24-C73 and C128-C201 in human Dkk4 (hDkk4). Here we report essentially complete backbone and comprehensive side chain (15)N, (13)C and (1)H NMR assignments for full length mature hDkk4 (M1-L207) containing a short C-terminal hexa-histidine tag (E208-H222). Analysis of the backbone chemical shift data obtained indicates that there is a very limited amount of regular secondary structure, with only small stretches of β-strand identified in both cysteine-rich regions. The N-terminal region of hDkk4 (M1-G21) and the relatively long linker between the two cysteine-rich regions (E77-Q123) appear to be unstructured and relatively mobile.

Notum is required for neural and head induction via Wnt deacylation, oxidation, and inactivation

Secreted Wnt morphogens are essential for embryogenesis and homeostasis and require a lipid/palmitoleoylate modification for receptor binding and activity. Notum is a secreted Wnt antagonist that belongs to the α/β hydrolase superfamily, but its mechanism of action and roles in vertebrate embryogenesis are not fully understood. Here, we report that Notum hydrolyzes the Wnt palmitoleoylate adduct extracellularly, resulting in inactivated Wnt proteins that form oxidized oligomers incapable of receptor binding. Thus, Notum is a Wnt deacylase, and palmitoleoylation is obligatory for the Wnt structure that maintains its active monomeric conformation. Notum is expressed in naive ectoderm and neural plate in Xenopus and is required for neural and head induction. These findings suggest that Notum is a prerequisite for the "default" neural fate and that distinct mechanisms of Wnt inactivation by the Tiki protease in the Organizer and the Notum deacylase in presumptive neuroectoderm orchestrate vertebrate brain development.