Wnt Pathway Inhibitor Research Articles

MiR-191-5p inhibits lung adenocarcinoma by repressing SATB1 to inhibit Wnt pathway.

MiR-191-5p inhibits lung adenocarcinoma by repressing SATB1 to inhibit Wnt pathway.

Metaphyseal Stromal Progenitor Cells Are Skewed Via Wnt-Activation Towards Osteogenesis in Progressed Myelofibrosis

Bone remodeling occurs actively alongside bone marrow (BM) fibrosis in the context of myeloproliferative neoplasms (MPN). Osteosclerosis in MPN is characterized by para-trabecular apposition of new bone and increase in bone density. Yet, the pathogenesis of osteosclerosis is largely unknown and it remains an unanswered question how the 1) peri-vascular, and 2) endosteal stromal niche contribute to the formation of new bone. Here, we employed genetic fate tracing and high-resolution imaging combined with single-cell RNA sequencing (scRNAseq) to map out the BM stromal niche in steady-state, after transplant of control or thrombopoietin (ThPO)-overexpressing hematopoietic stem and progenitor cells (HSPCs) which robustly and with defined kinetics results in BM fibrosis/osteosclerosis. High-resolution confocal imaging revealed that PdgfrbCreERt2-derived tdTomato+ cells are abundant throughout the whole marrow, growth plate and bone. Gli1CreERt2;tdTomato+ have a distinct localization specifically at the growth plate, in the trabecular region of the metaphysis and around the central artery in the diaphysis. Grem1CreERt2;tdTomato+ cells are the least abundant, specifically located at the growth plate. Integrated data sets provided a high resolution of the BM stroma representing Cxcl12-abundant reticular (CAR) cells, fibroblasts (FBs), osteo-lineage cells (OLCs), osteoblasts (OBs), (pre)chondrocytes, Schwann cells and endothelial subpopulations. We next asked how these different subsets contribute to BM fibrosis and osteosclerosis. CAR cells were functionally reprogrammed in fibrosis: they lost their hematopoiesis-supporting capacity, gained a pro-fibrotic phenotype, produced extra-cellular matrix (ECM) and were less frequent compared to control conditions. BM-resident FBs rather gained a pro-inflammatory phenotype, comparable to inflammatory fibroblasts described in solid organ fibrosis, and were enriched in fibrosis but did not show a "pro-fibrotic" expression profile. Strikingly, the major expansion of tdTomato+ stromal cells occurred at the metaphysis, overlapping with increased reticulin deposition in this region. Deconvolution revealed that mainly OLCs, pre-chondrocytes and chondrocytes but also FBs reside in the metaphysis. Cell trajectory analysis suggested that a subset of OLCs acts as a mesenchymal precursor reservoir for OBs, chondrocytes and FBs. In line with our hypothesis, only metaphyseal, but not diaphyseal, PdgfrbCreERt2;tdTomato+ cells from steady-state mice harbored CFU-F capacity and gave rise to colonies in vitro. Receptor-ligand interaction demonstrated that OLCs function as important information-hubs to CAR cells after BM transplantation compared to steady-state bone. This pro-regenerative phase is characterized by upregulation of adipogenesis-related genes, potentially prompting the BM niche to recover hematopoiesis. In response to a fibrotic cue, OLCs expand, lose cellular crosstalk reflected by decreased receptor-ligand pairs, downregulate adipogenic signatures but upregulate osteogenic signatures, thus skewing the BM stroma towards osteogenesis. Time-course imaging of the stepwise invasion of Gli1CreERt2;tdTomato+ cells into the BM from the growth plate additionally highlighted the active bone remodeling occurring at the chondrocyte-OLC border during fibrosis. µCT imaging revealed increased ossification specifically at the metaphyseal region. Pathways analysis demonstrated that metaphyseal cells remain active even in progressed fibrosis and show enriched Wnt, PI3K and ECM receptor signaling. Interestingly, Wnt pathway inhibitors were downregulated in pro-fibrotic-CAR cells, whereas Wnt signaling was increased in OLCs as mesenchymal progenitor cells upon fibrotic transformation. In summary, we provide evidence that active bone remodeling is co-occurring with the fibrotic transformation with a skewing of stromal-cell fate towards osteogenesis rather than adipogenesis. Our analysis highlights the functional differences of metaphyseal and diaphyseal macro-niches within bone and postulates that a metaphyseal stromal progenitor is activated in an injury-specific manner, being an attractive cellular target.

Wnt and Notch Pathways Regulate Stemness of Myeloid Leukemia Cells Via IL33/ST2 Signaling

Therapy-resistant leukemic stem cells (LSCs) are a main cause of relapse in chronic and acute myeloid leukemia (CML and AML) patients. Stemness, a cellular state of LSCs characterized by their quiescence, pluripotency, and long-term self-renewal capacity, is thought to have major implications on therapy resistance and outcome in myeloid leukemias. However, signaling pathways that induce stemness are often not specific for LSCs and shared with normal hematopoietic stem cells (HSCs). Therefore, LSCs are difficult to be targeted therapeutically. IL-33/ST2 signaling may be a potential target to eradicate CML and AML LSCs. To investigate the ST2 gene (IL1RL1) expression in different hematological malignancies, we used the MILE gene expression dataset containing 2096 samples. The IL1RL1 high expressing samples (n=62) were exclusively represented by myeloid leukemias (CML and AML), and 50% of the IL1RL1 high samples harbored either the BCR/ABL1 (CML) or the AML1/ETO (AML) oncogenes. We confirmed the result from the MILE database by analyzing the ST2 protein expression on FACS-sorted CD34+ LSCs from AML and CML patient samples. Indeed, AML1/ETO and BCR/ABL1 harboring LSCs expressed ST2, while healthy hematopoietic stem cells (HSCs) and LSCs harboring other oncogenes were ST2-negative. Transfecting the ST2-negative cell line Ramos with the AML1/ETO and BCR/ABL1 oncogenes induced ST2-expression. Next, we performed a gene set enrichment analysis (GSEA), comparing the IL1RL1 high vs. IL1RL1 low samples in the MILE dataset. Genes involved in stemness (p<0.01), Wnt- (p<0.001), and NF-ΚB (p=0.054) signaling were upregulated, while the Notch-pathway (p<0.05) was downregulated. Since the NF-ΚB is a known downstream pathway of ST2, we hypothesized that Wnt and/or Notch signaling pathways regulate ST2 expression. Therefore, we treated FACS-sorted CD34+ AML1/ETO expressing LSCs with the Wnt pathway inhibitor XAV939 or HES1 and NOTCH1 shRNAs, silencing the Notch pathway. Treatment with XAV939 led to a decrease in ST2 expression in these cells, while silencing HES1 and NOTCH1 enhanced ST2-expression. To analyze the molecular mechanisms induced by IL-33/ST2 signaling, we performed a transcriptomic analysis using FACS-sorted CD34+ AML1/ETO LSCs upon treatment with or without IL-33. In total, 377 genes were up- and 139 genes downregulated after IL-33 stimulation. IL-33-induced genes were involved in the positive regulation of NF-ΚB (p<0.05) and canonical Wnt (p<0.001) signaling pathways, and the regulation of stem cell division and maintenance (p<0.001). To functionally test whether IL-33/ST2 signaling triggers stemness in myeloid leukemia, we performed a colony forming assay using CD34+ AML1/ETO or BCR/ABL1 expressing LSCs from leukemia patient samples. The colony numbers increased 1.5-3fold upon IL-33 treatment in three consecutive platings, indicating an increase in stem cell numbers. IL-33 had no effect on colony numbers of HSCs and LSCs harboring other oncogenes. To test the in vivo relevance of IL-33/ST2 signaling in leukemia development, we used a congenic AML1/ETO9a (AE9a) or BCR/ABL1 (CML) mouse model. Briefly, we transduced ST2-negative HSCs originating from BL/6 or ST2-knockout (ST2-/-) mice with AE9a-GFP or BCR/ABL1-GFP and transplanted those cells into recipients. In both models, the LSCs strongly expressed ST2, but IL-33/ST2 signaling had no influence on the disease development. Stemness supports resistance against standard therapy in both, AML and CML. Since we were able to show that IL-33/ST2 signaling promotes stemness in AML1/ETO and BCR/ABL1 LSCs, we hypothesized that IL-33 addition protects LSCs from treatment with standard therapeutics. Indeed, IL-33 rescued the reduced colony forming capacity of LSCs that were either treated with the chemotherapeutic agent cytarabine (AML1/ETO LSCs) or the tyrosine kinase inhibitor Nilotinib (BCR/ABL1 LSCs). Furthermore, ST2-deficiency led to a reduced LSC count in CML mice compared to control mice when treated with Nilotinib (p=0.047). We showed that ST2 is expressed on AML1/ETO and BCR/ABL1 harboring LSCs and that activated IL-33/ST2 signaling induced stemness in these LSCs. Targeting IL-33/ST2 signaling in these specific subtypes of AML and CML may eliminate LSCs and overcome resistance towards chemotherapy or TKIs. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical significancy of WNT pathway inhibition in various cancers

The tumor microenvironment (TME) plays an important role in the cell cycle. There is a correlation between the Wnt/B–catenin signaling pathway and TME. This article reviews methods of inhibiting Wnt Pathway, a useful process in the treatment of various cancers. Compounds of Wnt/β–Catenin Signaling Pathway, such as TCF–1, have an impact on the differentiation and migration of CD8+ T cells. CCL4 expression is regulated by the beta–catenin protein to recruit CD103+ dendritic cells, which enables CD8+ T cell activation. Inhibition of the Wnt/β–catenin pathway has an impact on ovarian cancer patients’ prognosis, reducing the development of ovarian cancer. Research shows that inhibition of the pathway with the use of the LGK974 inhibitor may boost immunity, especially when applied with a Paclitaxel mix. After treatment, expression of the inhibitory receptors CTLA–4, TIM3, PD–1 on CD8+ T cells decreased. The combination of LGK974 and Paclitaxel can cause the death of tumor cells and significantly inhibit their proliferation. The application of dose–dense Paclitaxel avoids toxicity related to the maximum dose needed to protect the patient's immune system by increasing CD8+ TILs. There are concerns regarding toxicity of the LGK 974, especially for cells dependent on the Wnt/β–catenin pathway to maintain homeostasis. Many Wnt/β–catenin pathway inhibitors are tested against colorectal cancer (CRC) with successful results. These include NSAIDs, porcupine inhibitors, tankyrase inhibitors, Wnt5A inhibitors, and disheveled protein inhibitors.The Wnt/β–catenin pathway, when expressed in Triple Negative Breast Cancer (TNBC), leads to the transition of epithelial to mesenchymal cells. In early clinical development, there are multiple inhibitors (ex. KYA1797K) targeting the Wnt/β–catenin pathway in TNBC cells, which could become a viable anticancer strategy.

Wnt-pathway inhibitors with selective activity against triple-negative breast cancer: From thienopyrimidine to quinazoline inhibitors.

The Wnt-pathway has a critical role in development and tissue homeostasis and has attracted increased attention to develop anticancer drugs due to its aberrant activation in many cancers. In this study, we identified a novel small molecule series with a thienopyrimidine scaffold acting as a downstream inhibitor of the β-catenin-dependent Wnt-pathway. This novel chemotype was investigated using Wnt-dependent triple-negative breast cancer (TNBC) cell lines. Structure activity relationship (SAR) exploration led to identification of low micromolar compounds such as 5a, 5d, 5e and a novel series with quinazoline scaffold such as 9d. Further investigation showed translation of activity to inhibit cancer survival of HCC1395 and MDA-MB-468 TNBC cell lines without affecting a non-cancerous breast epithelial cell line MCF10a. This anti-proliferative effect was synergistic to docetaxel treatment. Collectively, we identified novel chemotypes acting as a downstream inhibitor of β-catenin-dependent Wnt-pathway that could expand therapeutic options to manage TNBC.

FAM96A and FAM96B function as new tumor suppressor genes in breast cancer through regulation of the Wnt/β-catenin signaling pathway

AimsFamily with sequence similarity 96 member A and B (FAM96A and FAM96B) are two highly conserved homologous proteins belonging to MIP18 family. Some studies have shown that FAM96A and FAM96B are significantly down-regulated in human gastrointestinal stromal tumors, colon cancer, and liver cancer. However, the molecular mechanisms of FAM96A/B in breast cancer are unknown. This work aims to explore the roles of FAM96A/B in breast cancer progression. Main methodsSpecific siRNAs were used to down-regulate FAM96A/B expression, and recombinant plasmids were used to up-regulate FAM96A/B expression in breast cancer cells. Cell proliferation was measured using MTT and colony formation. Cell cycle and apoptosis were detected by flow cytometry. Cell migration and invasion were examined by wound healing and transwell assays. The relationships among FAM96A/B, EMT and Wnt/β-catenin pathway were determined by analyzing expression changes of classical markers. Key findingsWe found that FAM96A/B expression was down-regulated in breast cancer. FAM96A/B overexpression suppressed breast cancer cell proliferation, invasion and migration, induced cell apoptosis and caused cell cycle arrest. Conversely, FAM96A/B knockdown exhibited the opposite effects. Moreover, our data demonstrated that FAM96A/B overexpression suppressed EMT and Wnt/β-catenin pathway, while FAM96A/B knockdown showed the promoting effects on EMT and Wnt/β-catenin pathway. Furthermore, a Wnt pathway inhibitor, XAV-939 reversed the promoting effects of FAM96A/B knockdown on breast cancer progression. SignificanceOur findings suggest that FAM96A/B may function as new tumor suppressor genes and inhibit breast cancer progression via modulating Wnt/β-catenin pathway, which can provide the potential markers for breast cancer diagnosis and therapy.

Rapid and robust directed differentiation of mouse epiblast stem cells into definitive endoderm and forebrain organoids.

Directed differentiation of pluripotent stem cells (PSCs) is a powerful model system for deconstructing embryonic development. Although mice are the most advanced mammalian model system for genetic studies of embryonic development, state-of-the-art protocols for directed differentiation of mouse PSCs into defined lineages require additional steps and generates target cell types with lower purity than analogous protocols for human PSCs, limiting their application as models for mechanistic studies of development. Here, we examine the potential of mouse epiblast stem cells cultured in media containing Wnt pathway inhibitors as a starting point for directed differentiation. As a proof of concept, we focused our efforts on two specific cell/tissue types that have proven difficult to generate efficiently and reproducibly from mouse embryonic stem cells: definitive endoderm and neural organoids. We present new protocols for rapid generation of nearly pure definitive endoderm and forebrain-patterned neural organoids that model the development of prethalamic and hippocampal neurons. These differentiation models present new possibilities for combining mouse genetic tools with in vitro differentiation to characterize molecular and cellular mechanisms of embryonic development.

Phytochemical Investigation of Egyptian Riverhemp: A Potential Source of Antileukemic Metabolites

As part of our research group’s continuous efforts to find alternative treatments for cancer, the aqueous ethanol extract of Sesbania sesban L. Merr. (SS, Egyptian riverhemp) demonstrated an antileukemic activity against K562 cell line. Bioguided fractionation of SS leaves hydroethanolic extract resulted in the isolation of one new compound (33) named as hederatriol 3-O-β-D-glucuronic acid methyl ester as well as 34 known compounds. Seven compounds ((34), (22), (20), (24), (21), (19), and (35)) showed high antiproliferative effects (IC50 = 22.3, 30.8, 31.3, 33.7, 36.6, 37.5, and 41.5 μM, respectively), while four compounds ((32), (5), (29), and (1)) showed milder activities (IC50 = 56.4, 67.6, 83.3, and 112.3 μM, respectively). A mechanistic study was further carried out on a molecular genetics level against several transcription factors signaling pathways that are incorporated in the incidence of cancer. The results showed that compounds (22) and (21) demonstrated a specific inhibition of Wnt pathway (IC50 = 3.8 and 4.6 μM, respectively), while compound (22) showed a specific inhibition of Smad pathway (IC50 = 3.8 μM). Compound (34) strongly altered the signaling of Smad and E2F pathways (IC50 = 5 μM). The bioactive metabolites were further investigated in silico by docking against several targets related to K562 cell line. The results showed that compounds (22) and (34) exhibited a strong binding affinity towards topoisomerase (docking score = −7.81 and −9.30 Kcal/Mole, respectively). Compounds (22) and (34) demonstrated a strong binding affinity towards EGFR-tyrosine kinase (docking score = −7.12 and −7.35 Kcal/Mole, respectively). Moreover, compound (34) showed a strong binding affinity towards Abl kinase (docking score = −7.05 Kcal/Mole).

Neuroprotection of Bone Marrow-Derived Mesenchymal Stem Cell-Derived Extracellular Vesicle-Enclosed miR-410 Correlates with HDAC4 Knockdown in Hypoxic-Ischemic Brain Damage.

Evidence exists reporting that miR-410 may rescue neurological deficits, neuronal injury, and neuronal apoptosis after experimental hypoxic ischemia. This study aimed to explore the mechanism by which miR-410 transferred by bone marrow-derived mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) may alleviate hypoxic-ischemic brain damage (HIBD) in newborn mice. BMSCs were isolated from total bone marrow cells of femur and tibia of newborn mice, and primary neurons were extracted from the cerebral cortex of newborn mice within 24h of birth. EVs were extracted from BMSCs transfected with the mimic or inhibitor of miR-410. Primary neurons were subjected to hypoxia and treated with overexpression (oe)-HDAC4, small interfering RNA (siRNA)-β-catenin, or Wnt pathway inhibitor and/or EV (miR-410 mimic) or EV (miR-410 inhibitor). A neonatal mouse HIBD model was established and treated with EVs. When BMSC-EVs were endocytosed by primary neurons, miR-410 was upregulated, neuronal viability was elevated, and apoptosis was inhibited. miR-410 in BMSC-EVs targeted HDAC4, thus increasing neuronal viability and reducing apoptosis. Conversely, overexpression of HDAC4 activated the Wnt pathway and enhanced the nuclear translocation of β-catenin. Treatment with miR-410-containing BMSC-EVs improved learning and memory abilities of HIBD mice while attenuating apoptosis by inactivating the Wnt pathway via targeting HDAC4. Taken together, the findings suggest that miR-410 delivered by BMSC-EVs alleviates HIBD by inhibiting HDAC4-dependent Wnt pathway activation.

Directed differentiation of human pluripotent stem cells into diverse organ-specific mesenchyme of the digestive and respiratory systems.

Development of visceral organs such as the esophagus, lung, liver and stomach are coordinated by reciprocal signaling interactions between the endoderm and adjacent mesoderm cells in the fetal foregut. Although the recent successes in recapitulating developmental signaling in vitro has enabled the differentiation of human pluripotent stem cells (hPSCs) into various types of organ-specific endodermal epithelium, the generation of organ-specific mesenchyme has received much less attention. This is a major limitation in ongoing efforts to engineer complex human tissue. Here, we describe a protocol to differentiate hPSCs into different types of organ-specific mesoderm, leveraging signaling networks and molecular markers elucidated from single-cell transcriptomics of mouse foregut organogenesis. Building on established methods, hPSC-derived lateral plate mesoderm treated with either retinoic acid (RA) or RA together with a Hedgehog (HH) agonist generates posterior or anterior foregut splanchnic mesoderm, respectively, after 4-d cultures. These are directed into organ-specific mesenchyme lineages by the combinatorial activation or inhibition of WNT, BMP, RA or HH pathways from days 4 to 7 in cultures. By day 7, the cultures are enriched for different types of mesoderm with distinct molecular signatures: 60-90% pure liver septum transversum/mesothelium-like, 70-80% pure liver-like fibroblasts and populations of ~35% respiratory-like mesoderm, gastric-like mesoderm or esophageal-like mesoderm. This protocol can be performed by anyone with moderate experience differentiating hPSCs, provides a novel platform to study human mesoderm development and can be used to engineer more complex foregut tissue for disease modeling and regenerative medicine.

Effects of Wnt-β-Catenin Signaling and Sclerostin on the Phenotypes of Rat Pheochromocytoma PC12 Cells.

Pheochromocytomas and paragangliomas (PPGLs) are classified into 3 major categories with distinct driver genes: pseudohypoxia, kinase signaling, and Wnt-altered subtypes. PPGLs in the Wnt-altered subtype are sporadic and tend to be aggressive with metastasis, where somatic gene fusions affecting mastermind-like 3 (MAML3) and somatic mutations in cold shock domain containing E1 (CSDE1) cause overactivation of Wnt-β-catenin signaling. However, the relation between Wnt-β-catenin signaling and the biological behavior of PPGLs remains unexplored. In rat pheochromocytoma PC12 cells, Wnt3a treatment enhanced cell proliferation and suppressed mRNA expression of tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine biosynthesis, and dopamine secretion. We identified the expression of sclerostin in PC12 cells, which is known as an osteocyte-derived negative regulator for Wnt signaling-driven bone formation. Inhibition of endogenous Wnt pathway by XAV939 or sclerostin resulted in attenuated cell proliferation and increased TH expression. Furthermore, Wnt3a pretreatment suppressed bone morphogenetic protein (BMP)-induced Smad1/5/9 phosphorylation whereas BMPs enhanced sclerostin expression in PC12 cells. In the Wnt-altered subtype, the increased Wnt-β-catenin pathway may contribute the aggressive clinical behavior with reduced catecholamine production. Furthermore, upregulated expression of sclerostin by BMPs may explain the osteolytic metastatic lesions observed in metastatic PPGLs.

Endometrial cancer antitumor response with combination Wnt inhibition and taxanes (270)

<b>Objectives:</b> <i>CTNNB1</i> is a gene that codes for the b-catenin protein, involved in the Wnt/b-catenin pathway and associated with endometrial cancer (EC) recurrence. Biomarker-driven treatment strategies are an important avenue of research. M08502 is a novel pan-CLK inhibitor that targets mRNA splicing and is optimized for Wnt pathway inhibition. We aimed to evaluate the combination SM08502 and paclitaxel in the preclinical setting. <b>Methods:</b> <i>In vitro</i> and <i>in vivo</i> models were used to evaluate the combination SM08502 and paclitaxel in four EC cell lines. We studied two <i>CTNNB1</i> mutant cell lines (HEC 265, SNGM), one <i>CTNNB1</i> wildtype cell line (Ishikawa), and one <i>CTNNB1</i>-S33Y mutant cell line created via retroviral transduction (Ishikawa-S33Y). Dose-response curves and 50% inhibitory concentrations (IC50) were determined based on cell viability. Apoptosis was evaluated via Annexin V/propidium iodide (PI). TCF transcriptional activity was determined via TOP/FOP reporter assay. Combination index (CI) evaluation for synergy was evaluated using CompuSyn programming. Tumor-bearing athymic nude mice were treated with vehicle (PBS), daily SM08502 (orally, 12.5 mg/kg), weekly paclitaxel (10 mg/kg), or in combination with daily SM08502/weekly paclitaxel. Tumors were evaluated with immunohistochemistry for proliferation (Ki67). <b>Results:</b> SM08502 is an active single-agent therapy with IC50 in the nanomolar range for all four EC cell lines. Compared to control, 1200 nM SM08502 significantly induces apoptosis in Ishikawa (7.3% vs 16.63% AnnexinV/PI+, p < 0.0001), HEC265 (12.47% vs 39.9% AnnexinV/PI+, p < 0.0001), and SNGM (19.93% vs 67.3%, p < 0.0001), but not Ishikawa-S33Y. Compared to control, single-agent SM08502 (800 nM) significantly decreases TCF transcriptional activity in all four cell lines (HEC265: -93.9 %TCF activity, p < 0.0001; SNGM: -45.9%, p=0.03; Ishikawa-S33Y: -93.3%, p < 0.0001; Ishikawa: -93.1%, p < 0.0001). HEC265, Ishikawa-S33Y and Ishikawa cells all demonstrated a synergy with combination paclitaxel with CI <1. SNGM cells demonstrate an additive effect at all dose levels combined with paclitaxel. Ishikawa demonstrated significantly lower tumor volumes of combination versus SM08502 alone (Repeated Measures one-way ANOVA, p=0.04), but not versus paclitaxel alone. HEC265, SNGM, and Ishikawa-S33Y tumors all had significantly lower tumor volumes with combination of SM08502 and paclitaxel compared to single-agent paclitaxel (Repeated Measures one-way ANOVA, p=0.01, 0.004, and 0.0008, respectively) or single-agent SM08502 (Repeated Measures one-way ANOVA, p=0.002, 0.005, and 0.01, respectively) alone. <b>Conclusions:</b> TCF transcriptional Wnt inhibition combined with paclitaxel has a synergistic effect <i>in vitro</i> and inhibits tumor progression in four endometrial cancer models. Human clinical trials are warranted to evaluate this combination strategy.

SIRS tanılı hastalarda enflamasyon ve kemik döngüsü arasındaki ilişkinin sklerostin ve Dickkopf-1 (DKK-1) düzeyleri ile değerlendirilmesi

Introduction: In intensive care units (ICU), patients remain bedridden for a long time. In addition, severe infections are frequently seen in ICUs. Both prolonged immobilization and serious infections are associated with bone tissue loss. The Wnt pathway has recently been focused on evaluating bone tissue loss. The Wnt pathway participates in both infections and the formation of bone tissue. Wnt pathway inhibitors sclerostin and Dickkopf-1 (DKK-1) inhibit bone formation and increase osteoclastic activity. In this study, we aimed to examine bone turnover by the Wnt inhibitors sclerostin and DKK-1 and their possible associations with inflammation in SIRS patients.Methods: We included 30 patients diagnosed with systemic inflammatory response syndrome (SIRS) in the study group and 16 in the control group. Serum sclerostin, DKK-1, white blood cell (WBC), and C-Reactive Protein (CRP) levels on the day of SIRS diagnosis (basal), the 7th, 14th, and 21stdays were evaluated in the study group, and the results were compared with the control group.Results: When the control group was compared with the basal SIRS, there was a significant elevation in both sclerostin (p=0.003) and DKK-1 (p=0.001). Statistical analysis showed significant decreases in sclerostin levels between basal and the 7th, 14th, and 21st days (p=0.033, p=0.003, p=0.002, respectively). Similarly, significant decreases in DKK-1 levels between basal and the 7th and 21st days (p=0.015, p=0.001, respectively) and an insignificant decrease on the 14th day (p=0.191) was observed. Sclerostin was positively and significantly correlated with WBC and CRP in basal and 7th-day measurements and WBC in 7th and 14th days. DKK-1 is positively and significantly correlated with WBC in basal and 7th-daymeasurements, while DKK-1 negatively correlates with CRP in basal-7th-day measurements.Conclusion: In this study, it was shown for the first time that the Wnt antagonists sclerostin and DKK-1 values are high in SIRS patients in ICU. Both biomarker levels decreased in parallel with the treatment. However, it could not be associated with disease severity and inflammatory marker levels. We believe that monitoring the change of Wnt antagonists will be useful in demonstrating bone turnover in patients with SIRS.Keywords: Dickkopf-1, Intensive care unit, Sclerostin, Systemic inflammatory response syndrome, Wnt signaling pathway, Bone turnover

Hsa-miR-143-3p inhibits Wnt-β-catenin and MAPK signaling in human corneal epithelial stem cells

Our previous study demonstrated hsa-miR-143-3p as one of the highly expressed miRNAs in enriched corneal epithelial stem cells (CESCs). Hence this study aims to elucidate the regulatory role of hsa-miR-143-3p in the maintenance of stemness in CESCs. The target genes of hsa-miR-143-3p were predicted and subjected to pathway analysis to select the targets for functional studies. Primary cultured limbal epithelial cells were transfected with hsa-miR-143-3p mimic, inhibitor or scrambled sequence using Lipofectamine 3000. The transfected cells were analysed for (i) colony forming potential, (ii) expression of stem cell (SC) markers/ transcription factors (ABCG2, NANOG, OCT4, KLF4, ΔNp63), (iii) differentiation marker (Cx43), (iv) predicted five targets of hsa-miR-143-3p (DVL3, MAPK1, MAPK14, KRAS and KAT6A), (v) MAPK signaling regulators and (vi) Wnt-β-catenin signaling regulators by qPCR, immunofluorescence staining and/or Western blotting. High expression of hsa-miR-143-3p increased the colony forming potential (10.04 ± 1.35%, p < 0.001) with the ability to form holoclone-like colonies in comparison to control (3.33 ± 0.71%). The mimic treated cells had increased expression of SC markers but reduced expression of Cx43 and hsa-miR-143-3p targets involved in Wnt-β-catenin and MAPK signaling pathways. The expression of β-catenin, active β-catenin and ERK2 in hsa-miR-143-3p inhibitor transfected cells were higher than the control cells and the localized nuclear expression indicated the activation of Wnt and MAPK signaling. Thus, the probable association of hsa-miR-143-3p in the maintenance of CESCs through inhibition of Wnt and MAPK signaling pathways was thus indicated.

Abstract 2566: Pre-clinical efficacy of the Wnt pathway inhibitor RXC004 in combination with anti-cancer therapies

Abstract Background: RXC004, a potent and selective inhibitor of the Wnt pathway regulator Porcupine, is being investigated in phase 2 studies in patients with advanced cancers (NCT04907851 and NCT04907539). Wnt pathway alterations, including loss-of-function RNF43 mutations and RSPO gene fusions, result in higher levels of the Wnt receptor Frizzled (Fzd) on the cell surface increasing Wnt-ligand dependent signaling. These alterations, which have been shown to be sensitive to Porcupine inhibitors, are implicated in colorectal, gastric and pancreatic cancer. Pre-clinical in vivo data on the effects of RXC004 in combination with clinically relevant anti-cancer therapies have not previously been described in genetically-defined models of cancer. Methods: RXC004 was evaluated as a monotherapy, and in combination with clinically relevant chemotherapy regimens, in an RSPO-fusion colorectal xenograft model (SNU-1411). RXC004, dosed at 5mg/kg QD (5 days on/2 days off), was evaluated in combination with either the clinically relevant colorectal triplet chemotherapy regimen (5-fluorouracil 5-FU (25mg/kg), irinotecan (50mg/kg) and oxaliplatin (5mg/kg)) or doublet chemotherapy regimen (5-FU (25mg/kg), irinotecan (50mg/kg)). Each chemotherapy regimen was dosed once a week for 3 to 4 weeks either alone or in combination with RXC004, which was dosed from day 8 onwards at 5mg/kg QD (5 days on/2 days off). Efficacy was measured by tumor volume and survival endpoint. In addition, RXC004 was studied in vitro, as monotherapy and in combination with a PARP inhibitor in genetically selected cell lines with both RSPO-fusion and RNF43 mutation. Combination and monotherapy effects on proliferation and effects on downstream signaling were investigated. Results: RXC004 in combination with the triplet chemotherapy regimen led to significantly increased survival compared to either treatment alone (p&amp;lt;0.005) and significant tumor volume reduction measured at Day 22 (p&amp;lt;0.001). RXC004 in combination with the doublet chemotherapy also increased survival compared to either treatment alone (p&amp;lt;0.05), and the combination led to significantly decreased tumor volume measured at Day 25 (p&amp;lt;0.05). RXC004 treatment in genetically defined cell lines with RSPO fusions or RNF43 mutations led to a significant reduction in BRCA1 and BRCA2 gene expression. In in vitro proliferation studies a synergistic effect of RXC004 and a PARP inhibitor was demonstrated in genetically defined cell lines. Conclusion: These data demonstrate that RXC004 in combination with clinically relevant standard of care chemotherapy regimens can lead to potential benefit over chemotherapy alone. The RXC004 induced downregulation of DNA repair pathway genes observed in vitro could contribute to the beneficial effect seen in combination with a PARP inhibitor in vitro as well as the combination effect observed in vivo with standard of care chemotherapy agents. Citation Format: James Kelly, Simon Woodcock, Inder Bhamra, Cliff Jones, Richard Armer, Jane Robertson, Caroline Phillips. Pre-clinical efficacy of the Wnt pathway inhibitor RXC004 in combination with anti-cancer therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2566.

Abstract 5348: SEMA3C signaling confers resistance to Wnt Inhibition in glioblastoma

Abstract Background: Wnt signaling is widely dysregulated in cancer. The therapeutic potential of Wnt inhibitors appears promising in preclinical studies. However, they have uniformly failed clinical trials. How cancer cells develop Wnt inhibitor resistance is poorly understood. Current Wnt inhibitors are designed targeting either ligand or receptor. We hypothesized cancer cells will bypass ligand-receptor interaction through an unknown mechanism. We focused on the neurodevelopmental signaling program of Semaphorin 3C (Sema3C) that is upregulated in 85% of GBM and regulates glioma stem-cell-driven tumor progression. Methods: We analyzed the expression of Sema3C and TCF1 expression pattern in 32 human GBM samples by immunohistochemistry. GSC self-renewal was assessed by extreme limiting dilution, Edu incorporation, tumorsphere formation and cell survival assays in Sema3C silencing GSCs. Cell fractionation and immunofluorescence studies were performed to assess β-catenin sub-cellular localization in GSCs. GSC-derived mouse models were assessed for survival. Results: Porcupine inhibitor LGK974 reduced TCF1 expression in the GBM tumor mouse models, suggesting successful target engagement in vivo. However, it failed to prolong the overall survival. Sema3C expression strongly correlated with TCF1 expression in human GBM samples by immunohistochemical analysis. Genetic inhibition of Sema3C and TCF1 together prolonged animal survival more than either alone, indicating better control of Wnt pathway signaling with dual pathway blockade. Immunofluorescence and cell fractionation studies revealed that Sema3C signaling drove β-catenin nuclear accumulation. Sema3C regulates transactivation of Wnt target genes including TCF1, c-Myc and c-Met. Sema3C pathway activates Rac1. It is reported that Rac1 activates β-catenin and promotes β-catenin nuclear accumulation. In GSCs, constitutively active Rac1 restored β-catenin nuclear localization and rescued TCF1 and c-Myc down-regulation in the setting of Sema3C silencing. Sema3C can drive canonical Wnt signaling even when Wnt ligand secretion is blocked. Together, the data support that GSCs can escape Wnt inhibition through Sema3C and Rac1. Conclusions: Sema3C signaling drives canonical Wnt signaling, providing an escape mechanism for cancer cells despite Wnt ligand-receptor interruption. Sema3C-β-catenin signaling promotes GSC self-renewal and tumor progression. Upstream Wnt pathway inhibition alone is insufficient to control tumors. Our data provide a therapeutic strategy of dual blockade of Wnt and Sema3C pathways to provide clinically significant tumor control. Citation Format: Jing Hao. SEMA3C signaling confers resistance to Wnt Inhibition in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5348.

Recapitulating early human development with 8C-like cells.

In human embryos, major zygotic genome activation (ZGA) initiates at the eight-cell (8C) stage. Abnormal ZGA leads to developmental defects and even contributes to the failure of human blastocyst formation or implantation. An invitro cell model mimicking human 8C blastomeres would be invaluable to understanding the mechanisms regulating key biological events during early human development. Using the non-canonical promoter of LEUTX that putatively regulates human ZGA, we developed an 8C::mCherry reporter, which specifically marks the 8C state, to isolate rare 8C-like cells (8CLCs) from human preimplantation epiblast-like stem cells. The 8CLCs express a panel of human ZGA genes and have a unique transcriptome resembling that of the human 8C embryo. Using the 8C::mCherry reporter, we further optimize the chemical-based culture condition to increase and maintain the 8CLC population. Functionally, 8CLCs can self-organize to form blastocyst-like structures. The discovery and maintenance of 8CLCs provide an opportunity to recapitulate early human development.

MiR-18a Mediates Immune Evasion in ER-Positive Breast Cancer through Wnt Signaling.

ER-positive (ER+) breast cancer is considered immunologically ‘silent’ with fewer tumor-infiltrating immune cells. We have previously demonstrated the role of miR-18a in mediating invasion and poor prognosis in ER+ breast cancer by activation of the Wnt signaling pathway. Here, we explored the immune-modulatory functions of high levels of miR-18a in these tumors. A microarray-based gene expression analysis performed in miR-18a over-expressed ER+ breast cancer cell lines demonstrated dysregulation and suppression of immune-related pathways. Stratification of the ER+ tumor samples by miR-18a levels in the TCGA and METABRIC cohort and immune cell identification performed using CIBERSORT and Immune CellAI algorithms revealed a higher proportion of T-regulatory cells (p < 0.001) and a higher CD4/CD8 ratio (p < 0.01). miR-18a over-expressed MCF7 co-cultured with THP-1 showed decreased antigen presentation abilities and increased invasiveness and survival. They also promoted the differentiation of pro-tumorigenic M2 macrophages. Inhibition of the Wnt pathway in miR-18a over-expressed cells brought about the restoration of TAP-1, a protein critical for antigen presentation. Examination of tumor specimens from our case series showed that miR-18a high ER+ tumors had a dense lymphocyte infiltrate when compared to miR-18a low tumors but expressed a higher CD4/CD8 ratio and the M2 macrophage marker CD206, along with the invasive marker MMP9. We report for the first time an association between miR-18a-mediated Wnt signaling and stromal immune modulation in ER+ tumors. Our results highlight the possibility of formulating specific Wnt pathway inhibitors that may be used in combination with immune checkpoint blockers (ICB) for sensitizing ‘immune-cold’ ER+ tumors to immunotherapy.

Intra-articular injection of a novel Wnt pathway inhibitor, SM04690, upregulates Wnt16 expression and reduces disease progression in temporomandibular joint osteoarthritis.

Abnormal Wnt signaling has been shown to be involved in the pathogenesis of temporomandibular joint osteoarthritis (TMJOA). Recent studies demonstrates that SM04690, a small-molecule inhibitor of the Wnt signaling pathway, is able to promote cartilage regeneration in a rat model of knee joint osteoarthritis. However, whether SM04690 has any effect on TMJOA is unknown. Here we first performed partial TMJ discectomy to induce TMJOA in rabbit and rat. Histology, TRAP staining, immunohistochemistry and μCT analysis showed intra-articular injection of SM04690 protected condylar cartilage from degeneration and attenuated abnormal subchondral bone remodeling of TMJ condylar in both rabbit and rat model TMJOA. We isolated and cultured primary condylar chondrocytes for in vitro studies to investigate molecular mechanisms and downstream effects of SM04690. We found that SM04690 inhibited the canonical Wnt pathway, upregulated the expression of Wnt16 and cartilage anabolic factors including COL2A1, SOX9 and aggrecan, suppressed the expression of cartilage catabolic factor MMP13 and protected chondrocytes from TNF-α-induced inflammatory response. Previous studies have identified fibrocartilage stem cells (FCSCs) localized within the TMJ condyle superficial zone niche that regenerate cartilage and repair joint injury. Here we showed that intra-articular injection of SM04690 increased the number of the TMJ condyle superficial zone (SZ) cells in vivo. Further in vitro studies revealed that SM04690 enhanced FCSCs chondrogenesis and formation of cartilaginous-like tissue in pellet cultures. Taken together, our work demonstrates that SM04690 treatment might be able to promote FCSCs chondrogenesis and repair TMJ cartilage, highlighting the therapeutic potential of intra-articular injection of SM04690 in TMJOA.

Inhibition of Wnt/β‐catenin Signaling Pathway on Melanogenesis‐ Insights from Zebrafish (Danio rerio)

IntroductionVertebrate color patterns are composed of specialized pigment‐producing cells, the chromatophores. Melanin is the main pigment type that colors the skin and skin appendages in mammals. Melanin is produced by specialized cells called melanocytes. Melanocytes have embryonic neural crest cells origin and their development and functions are ubiquitous across vertebrates, residing in dermal and epidermal skin layers. Studies of melanogenesis have provided experimentalists with a valuable system for understanding pattern formation in the developing embryo. In addition, studying these mechanisms may have important consequences for the clinical sciences. Alcohol is a widely abused teratogenic substance. Fetal alcohol spectrum disorder (FASD) is described as birth defects associated with prenatal alcohol exposure (PAE). PAE is likely one of the leading causes of birth defects but pathophysiology of FASD associated body pigmentation disorders are needed to be investigated further. Zebrafish (Danio rerio) (ZF) is identified as a good model to study FASD and melanocyte biology. Wnt signaling pathway is a conserved signal transduction pathway which is important in embryonic development and it regulates many aspects of melanogenesis. The current study was designed to investigate the effect of Alcohol‐Wnt signaling pathway activity on ZF melanogenesis.Materials and MethodsWild‐type (WT) ZF embryos were treated with Wnt pathway inhibitor (LiCl) and combined chemical treatment (LiCl and 1% alcohol) at 10 hours post fertilization (hpf). The differential effects of above substances on early development, differentiation, patterning of melanocytes were investigated using cell biology and imaging techniques.ResultsMelanocytes of LiCl exposed samples showed defects in migration, arrangement and survival. Ectopic melanocytes and developmental aberrations of eye pigmentation were noticed in both chemical treatments. Significant variation of the melanocyte cell size, shape and body pigmentation patterning was observed among the LiCl and combined treated samples compared to the control.ConclusionEmbryonic LiCl and alcohol exposures affect the development and patterning of the melanocytes in ZF. The molecular mechanisms underlying the above phenotypes will be investigated further to understand the FASD associated pigmentation defects.