Role Of Wnt Signaling Pathway Research Articles

Connection between MiR-490 and CCND1 and GSK3β genes play an effective role in Wnt signaling pathway in colorectal cancer.

The Wnt signaling pathway is identified as one of the main disrupted pathways in Colorectal cancer (CRC). Results from studies focusing on this route will aid greatly in the detection and treatment of CRC. MicroRNAs (MiRs), particularly MiR-490, has emerged as key regulator of gene expression in biological pathways, making it an attractive research target. This is notably true for the Wnt signaling pathway, which is usually disordered in CRC tissues. This study aimed to evaluate the expression level of MiR-490 isomiRs and determine some of its key target genes involved in Wnt signaling pathway in CRC tissues and cell lines, based on experimental and bioinformatics analysis. Elevated expression of GSK3β and CCND1 indicate that the progression of CRC tumor is associated with the inhibitory effect of MiR-490 isomiRs on the Wnt/β-catenin signaling pathway. This finding was supported by the observation of a positive connection between the expression pattern of miR-490-3p and 5p, and CCND1 and GSK3β in CRC. The valuable results of this study provide a means of identifying biomarkers with the potential to either inhibit or activate CRC cellular pathways.

Abstract 264: Differentiation therapy: Esculetin as a potent agent to alter cellular plasticity of leukemic & solid tumor stem cells

Abstract Background The “Differentiation therapy” has been emerging as a promising and more effective strategy against acute leukemia relapses. Objective In extension to the revolutionising therapeutic outcomes of All Trans Retinoic Acid (ATRA) to induce terminal differentiation of Acute Promyelocytic Leukemic (APL) blast cells, we decipher the potential effect of a natural compound “Esculetin” to serve as a differentiating agent in Acute Myeloid Leukemia (AML) as well as solid tumour cells. Underlaying role of Wnt signaling pathways in esculetin mediated blast cell differentiation was also evaluated. Methods Human acute myeloid leukemic cells (Kasumi-1) with t(8;21/AML-ETO) translocation were used as a model system. Growth inhibitory and cytotoxic activity of esculetin were analysed using growth kinetics and MTT assay. Morphological alterations, cell scatter characteristics, NBT reduction assay and cell surface marker expression pat- terns were analysed to detect terminally differentiated phenotypes. We employed RT2profiler PCR array system for the analysis of transcriptome profile of Wnt signaling components. Calcium inhibitors (TMB8 and Amlodipine) and Transforming growth factor beta (TGF-β) were used to modulate the Wnt signaling axes. To investigate whether esculetin exerts the similar effects on the invasive solid tumour cancer stem cells subset, we used a cellular model system of colon carcinoma HCT116 cells reflecting EMT phenotype. Results We illustrate cytotoxic as well as blast cell differentiation potential of esculetin on Kasumi-1 cells. Morphological alterations akin to neutrophilic differentiation as well as the corresponding acquisition of myeloid lineage markers indicate terminal differentiation potential of esculetin in leukemic blast cells. Exposure to esculetin also resulted in downregulation of canonical Wnt axis while upto ~ 21 fold upregulation of non-canonical axis associated genes. Esculetin also showed potential to revert the CSC marker expressions and concurrent EMT consistent with reduced functional aggressiveness in colon cancer cells. Conclusions Our study highlights the importance of selective use of calcium pools as well as “axis shift” of the canonical to non-canonical Wnt signaling upon esculetin treatment which might abrogate the inherent proliferation to release maturation arrest and induce the differentiation in leukemic blast cells as well as CSC stem cells. The current findings provide further therapeutic interventions to consider esculetin as a potent differentiating agent to counteract relapses. Citation Format: Ankit Mathur, Daman Saluja. Differentiation therapy: Esculetin as a potent agent to alter cellular plasticity of leukemic & solid tumor stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 264.

Regeneration of amputated mice digit tips by including Wnt signaling pathway with CHIR99021 and IWP-2 chemicals in limb organ culture system.

Mammals have limited limb regeneration compared to amphibians. The role of Wnt signaling pathways in limb regeneration has rarely been studied. So, this study aimed to investigate the effect of Wnt-signaling using chemicals CHIR99021and IWP-2on amputated mice digit tips regeneration in aninvitroorgan culture system. The distal phalanx of paws from C57BL/6J mouse fetuses at E14.5, E16.5, and E18.5 was amputated.Then, the hands were cultured for 7 days.Subsequently, paws were treated with 1-50 µg/ml concentration of CHIR99021 and 5-10 µg/ml concentration of IWP-2. Finally, the new tissue regrowth was assessed by histological analysis, immunohistochemistry for BC, TCF1, CAN, K14, and P63 genes, and beta-catenin and Tcf1 genes were evaluated with RT-qPCR. The paws of E14.5 and E16.5 days were shrinkaged and compressed after 7 days, so the paws of 18.5E that were alive were selected.As a result, newly-grown masses at digit tips were observed in 25 and 30 µl/ml concentrations of the CHR99021 group but not in the IWP2 treatment (*P<0.05; **P<0.01). qRT-PCR analysis confirmed the significant up-regulation of beta-catenin and Tcf1 genes in CHIR99021 group in comparison to the IWP-2 group (P<0.05). Moreover, Alcian-blue staining demonstrated the presence of cartilage-like tissue at regenerated mass in the CHIR group. In immunohistochemistry analysis beta-catenin, ACN, Keratin-14, and P63 protein expression were observed in digit tips in the CHIR-treated group. By activating the Wnt signaling pathway, cartilage-like tissue formed in the blastema-like mass in the mouse's amputated digit tips.

The Roles of WNT Signaling Pathways in Skin Development and Mechanical-Stretch-Induced Skin Regeneration.

The WNT signaling pathway plays a critical role in a variety of biological processes, including development, adult tissue homeostasis maintenance, and stem cell regulation. Variations in skin conditions can influence the expression of the WNT signaling pathway. In light of the above, a deeper understanding of the specific mechanisms of the WNT signaling pathway in different physiological and pathological states of the skin holds the potential to significantly advance clinical treatments of skin-related diseases. In this review, we present a comprehensive analysis of the molecular and cellular mechanisms of the WNT signaling pathway in skin development, wound healing, and mechanical stretching. Our review sheds new light on the crucial role of the WNT signaling pathway in the regulation of skin physiology and pathology.

Genetic susceptibility of vitamin D receptor gene polymorphisms on autosomal recessive primary microcephaly patients in Pakistani population: a case-control and in-silico study.

Autosomal recessive primary microcephaly (MCPH) is a rare genetic disorder that leads to reduced cerebral cortex caused by a mutation in corticogenesis. The expression of the Vitamin D receptor (VDR) gene is involved in the proliferation and differentiation of neural stem cells, and VDR polymorphisms have been associated with various neurological disorders. However, their relationship with MCPH has not been explored. This study aimed to investigate the association of VDR polymorphisms with MCPH due to its role in Wnt signaling pathway and its In-silico analysis. Blood samples of 64 MCPH patients and 52 controls were collected to genotype VDR SNPs (TaqI (rs731236), FokI (rs2228570) and BsmI (rs1544410). In-silico tools were also used to assess the effects of exonic SNPs on mRNA and protein structure and pathogenicity of exonic and intronic SNPs. The study found that serum 25-OH vitamin D3 levels were significantly different in MCPH patients and healthy controls (P = 0.000). The genetic analysis showed that VDR polymorphisms of FokI and BsmI were seven times more frequent in MCPH patients than in controls (P < 0.05) and the recessive model for TaqI and dominant model for BsmI polymorphisms were also associated with the pathogenesis of MCPH. In-silico analysis showed that the pathogenicity effects of rs2228570 and rs1544410 are neutral while rs731236 causes a silent mutation which has no effect on VDR protein. VDR polymorphisms of FokI and BsmI are associated with the risk of MCPH. These findings suggest that VDR polymorphisms play a role in MCPH, which could provide important insights for understanding the molecular mechanisms of the disease.

Role of Wnt signaling pathway in joint development and cartilage degeneration.

Osteoarthritis (OA) is a prevalent musculoskeletal disease that affects approximately 500 million people worldwide. Unfortunately, there is currently no effective treatment available to stop or delay the degenerative progression of joint disease. Wnt signaling pathways play fundamental roles in the regulation of growth, development, and homeostasis of articular cartilage. This review aims to summarize the role of Wnt pathways in joint development during embryonic stages and in cartilage maintenance throughout adult life. Specifically, we focus on aberrant mechanical loading and inflammation as major players in OA progression. Excessive mechanical load activates Wnt pathway in chondrocytes, resulting in chondrocyte apoptosis, matrix destruction and other osteoarthritis-related changes. Additionally, we discuss emerging Wnt-related modulators and present an overview of emerging treatments of OA targeting Wnt signaling. Ultimately, this review provides valuable insights towards discovering new drugs or gene therapies targeting Wnt signaling pathway for diagnosing and treating osteoarthritis and other degenerative joint diseases.

Esculetin releases maturation arrest and induces terminal differentiation in leukemic blast cells by altering the Wnt signaling axes

BackgroundThe “Differentiation therapy” has been emerging as a promising and more effective strategy against acute leukemia relapses.ObjectiveIn extension to the revolutionising therapeutic outcomes of All Trans Retinoic Acid (ATRA) to induce terminal differentiation of Acute Promyelocytic Leukemic (APL) blast cells, we decipher the potential effect of a natural compound “Esculetin” to serve as a differentiating agent in Acute Myeloid Leukemia (AML). Underlaying role of Wnt signaling pathways in esculetin mediated blast cell differentiation was also evaluated.MethodsHuman acute myeloid leukemic cells (Kasumi-1) with t(8;21/AML-ETO) translocation were used as a model system. Growth inhibitory and cytotoxic activity of esculetin were analysed using growth kinetics and MTT assay. Morphological alterations, cell scatter characteristics, NBT reduction assay and cell surface marker expression patterns were analysed to detect terminally differentiated phenotypes. We employed RT2profiler PCR array system for the analysis of transcriptome profile of Wnt signaling components. Calcium inhibitors (TMB8 and Amlodipine) and Transforming growth factor beta (TGF-β) were used to modulate the Wnt signaling axes.ResultsWe illustrate cytotoxic as well as blast cell differentiation potential of esculetin on Kasumi-1 cells. Morphological alterations akin to neutrophilic differentiation as well as the corresponding acquisition of myeloid lineage markers indicate terminal differentiation potential of esculetin in leukemic blast cells. Exposure to esculetin also resulted in downregulation of canonical Wnt axis while upto ~ 21 fold upregulation of non-canonical axis associated genes.ConclusionsOur study highlights the importance of selective use of calcium pools as well as “axis shift” of the canonical to non-canonical Wnt signaling upon esculetin treatment which might abrogate the inherent proliferation to release maturation arrest and induce the differentiation in leukemic blast cells. The current findings provide further therapeutic interventions to consider esculetin as a potent differentiating agent to counteract AML relapses.

Involvement of canonical Wnt/β-catenin signaling in the extinction of auditory fear conditioning in male mice

The Wnt signaling pathway plays a critical role in activity-dependent plasticity processes such as long-term potentiation, learning and memory. However, the role of the Wnt signaling pathway in adult extinction is still not well understood. In this study, we aimed to investigate the roles and mechanisms of the canonical Wnt/β-catenin signaling pathway in the extinction of auditory fear conditioning (AFC) in adult mice. We found that AFC extinction training induced a significant decrease in p-GSK3β and nuclear β-catenin in the medial prefrontal cortex (mPFC). Micro-infusion of the canonical Wnt inhibitor Dkk1 into the mPFC before AFC extinction training facilitated AFC extinction, suggesting that the Wnt/β-catenin pathway is involved in AFC extinction. To determine how Dkk1 affects canonical Wnt/β-catenin signaling in AFC extinction, the protein levels of p-GSK3β and β-catenin were measured. We found that DKK1 produces a decrease in p-GSK3β and β-catenin. Moreover, we found that upregulating the Wnt/β-catenin pathway using LiCl (2 µg/side) impaired AFC extinction. These findings may help us understand the role of canonical Wnt signaling pathway in memory extinction and suggest that appropriate manipulating the Wnt/β-catenin signaling pathway might be a suitable way of therapeutically treating psychiatric disorders.

Porcupine inhibitor CGX1321 alleviates heart failure with preserved ejection fraction in mice by blocking WNT signaling.

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, and lacks effective treatment. The aberration of WNT pathway underlies many pathological processes including cardiac fibrosis and hypertrophy, while porcupine is an acyltransferase essential for the secretion of WNT ligands. In this study we investigated the role of WNT signaling pathway in HFpEF as well as whether blocking WNT signaling by a novel porcupine inhibitor CGX1321 alleviated HFpEF. We established two experimental HFpEF mouse models, namely the UNX/DOCA model and high fat diet/L-NAME ("two-hit") model. The UNX/DOCA and "two-hit" mice were treated with CGX1321 (3 mg·kg-1·d-1) for 4 and 10 weeks, respectively. We showed that CGX1321 treatment significantly alleviated cardiac hypertrophy and fibrosis, thereby improving cardiac diastolic function and exercise performance in both models. Furthermore, both canonical and non-canonical WNT signaling pathways were activated, and most WNT proteins, especially WNT3a and WNT5a, were upregulated during the development of HEpEF in mice. CGX1321 treatment inhibited the secretion of WNT ligands and repressed both canonical and non-canonical WNT pathways, evidenced by the reduced phosphorylation of c-Jun and the nuclear translocation of β-catenin and NFATc3. In an in vitro HFpEF model, MCM and ISO-treated cardiomyocytes, knockdown of porcupine by siRNA leads to a similar inhibitory effect on WNT pathways, cardiomyocyte hypertrophy and cardiac fibroblast activation as CGX1321 did, whereas supplementation of WNT3a and WNT5a reversed the anti-hypertrophy and anti-fibrosis effect of CGX1321. We conclude that WNT signaling activation plays an essential role in the pathogenesis of HFpEF, and porcupine inhibitor CGX1321 exerts a therapeutic effect on HFpEF in mice by attenuating cardiac hypertrophy, alleviating cardiac fibrosis and improving cardiac diastolic function.

Possible Role of Wnt Signaling Pathway in Diabetic Retinopathy.

The core of impaired vision in working people suffering from insulin-dependent and noninsulin- dependent diabetes mellitus is diabetic retinopathy (DR). The Wnt Protein Ligands family influences various processes; this ensures the cells are able to interact and co-ordinate various mobile functions, including cell growth, division, survival, apoptosis, migration, and cell destiny. The extracellular Wnt signal activates other signals. It is seen that Wnt pathways play an important role in inflammation, oxidative stress, and angiogenesis. It has been illustrated that the canonically preserved Wnt signaling system has a vital role in the homeostasis of adulthood. Developmental disorders in each of these stages will lead to serious eye problems and eventually blindness. There is, therefore, a need to specifically organize and regulate the growth of ocular tissues. In tissue specification and polarities, axonal exhaust, and maintenance of cells, especially in the central nervous system, Wnt/frizzled pathways play an important role. Thus, Wnt route antagonists may act as have been possible therapeutic options in DR by inhibiting aberrant Wnt signals. Elaborative and continued research in this area will help in the advancement of current knowledge in the field of DR, and eventually, this can lead to the development of new therapeutic approaches.

Human Placenta-Derived Mesenchymal Stem Cells Ameliorate Diabetic Neuropathy via Wnt Signaling Pathway.

To investigate the effect of placenta-derived mesenchymal stem cells (PMSCs) on diabetic peripheral neuropathy and explore the role of Wnt signaling pathway. Twenty-seven male db/db mice were randomly categorized into the control group, PMSC group, and PMSC treatment with Wnt inhibitor treatment group. Intervention was initiated in week 22. Thermal stimulation response was determined with a plantar analgesia tester. The mice were sacrificed on 7, 14, and 28 days. The morphology of sciatic nerves was observed by electron microscopy, and the expression of protein gene product (PGP) 9.5, S100β, and Ku80 was detected by immunofluorescence. Bax, β-catenin, and dishevelled1 (DVL1) were detected by western blot. Thermal stimulation response was improved in the PMSC group on 14 and 28 days. Compared with the control group, PGP9.5 was increased in the PMSC group, accompanied by a significant increase in the expression of S100β. On the contrary, LGK974 inhibited the effect of PMSCs on thermal stimulation response and the expression of PGP9.5 and S100β. Both PGP9.5 and S100β were correlated with Ku80 in fluorescence colocalization. The myelin sheath of sciatic nerves in the PMSC group was uniform and dense compared with that in the control group. The effects of PMSCs promoting myelin repair were significantly inhibited in the PMSC+LGK974 group. Bax in the PMSC group expressed less than the control group. In contrast, the expressions of β-catenin and DVL1 were higher compared with that in the control group on the 14th and 28th days. The expression of DVL1 and β-catenin was lower in the PMSC+LGK974 group than in the PMSC group. PMSCs improved the symptoms of diabetic peripheral neuropathy, along with the improvement of nerve myelin lesions, promotion of nerve regeneration, and activation of Schwann cells, which might be related to the regulation of Wnt signaling pathway and inhibition of apoptosis.

The organizing role of Wnt signaling pathway during arthropod posterior growth.

Wnt signaling pathways are recognized for having major roles in tissue patterning and cell proliferation. In the last years, remarkable progress has been made in elucidating the molecular and cellular mechanisms that underlie sequential segmentation and axial elongation in various arthropods, and the canonical Wnt pathway has emerged as an essential factor in these processes. Here we review, with a comparative perspective, the current evidence concerning the participation of this pathway during posterior growth, its degree of conservation among the different subphyla within Arthropoda and its relationship with the rest of the gene regulatory network involved. Furthermore, we discuss how this signaling pathway could regulate segmentation to establish this repetitive pattern and, at the same time, probably modulate different cellular processes precisely coupled to axial elongation. Based on the information collected, we suggest that this pathway plays an organizing role in the formation of the body segments through the regulation of the dynamic expression of segmentation genes, via controlling the caudal gene, at the posterior region of the embryo/larva, that is necessary for the correct sequential formation of body segments in most arthropods and possibly in their common segmented ancestor. On the other hand, there is insufficient evidence to link this pathway to axial elongation by controlling its main cellular processes, such as convergent extension and cell proliferation. However, conclusions are premature until more studies incorporating diverse arthropods are carried out.

Comparative liver transcriptome analysis of duck reveals potential genes associated with egg production.

Molecular studies on egg production in ducks were mostly focused on brain and ovaries as they are directly involved in egg production. Liver plays a vital role in cellular lipid metabolism. It also plays a decisive role in reproductive organ development, including yolk generation in laying ducks at sexual maturity. However, the precise molecular mechanism involved in the liver-blood-ovary axis in ducks remains elusive. In this study, we analysed the liver transcriptome of laying (LA), immature (IM) and broody (BR) ducks using RNA sequencing to understand the role of genes expressed in the liver. The comparative transcriptome analysis revealed 82 DEGs between LA and IM ducks, 47 DEGs between LA and BR ducks and 51 DEGs between IM and BR ducks. GO analysis of DEGs, showed that DEGs were mainly involved in cellular anatomical entity, intracellular, metabolic process, and binding. Furthermore, pathway analysis indicated the important role of Wnt signaling pathway in egg formation and embryo development. Our study showed several candidate genes including vitellogenin-1, vitellogenin-2, riboflavin binding protein, G protein subunit gamma 4, and fatty acid binding protein 3 that are potentially related to egg production in ducks. The study provides valuable information on the genes responsible for egg production and thus, pave the way for further investigation on the molecular mechanisms of egg production in duck.

Roles of Wnt Signaling Pathway and ROR2 Receptor in Embryonic Development: An Update Review Article.

The Wnt family is a large class of highly conserved cysteine-rich secretory glycoproteins that play a vital role in various cellular and physiological courses through different signaling pathways during embryogenesis and tissue homeostasis 3. Wnt5a is a secreted glycoprotein that belongs to the noncanonical Wnt family and is involved in a wide range of developmental and tissue homeostasis. A growing body of evidence suggests that Wnt5a affects embryonic development, signaling through various receptors, starting with the activation of β-catenin by Wnt5a. In addition to affecting planar cell polarity and Ca2+ pathways, β-catenin also includes multiple signaling cascades that regulate various cell functions. Secondly, Wnt5a can bind to Ror receptors to mediate noncanonical Wnt signaling and a significant ligand for Ror2 in vertebrates. Consistent with the multiple functions of Wnt5A/Ror2 signaling, Wnt5A knockout mice exhibited various phenotypic defects, including an inability to extend the anterior and posterior axes of the embryo. Numerous essential roles of Wnt5a/Ror2 in development have been demonstrated. Therefore, Ror signaling pathway become a necessary target for diagnosing and treating human diseases. The Wnt5a- Ror2 signaling pathway as a critical factor has attracted extensive attention.

Activation of mir-30a-wnt/β-catenin signaling pathway upregulates cathepsin K expression to promote cementogenic differentiation of periodontal ligament stem cells

To explore the role of cathepsin K (CTSK) regulated by mir-30a-wnt/β-catenin signaling pathway in cementogenic differentiation of periodontal ligament stem cells (PDLSCs). Human PDLSCs isolated by limiting dilution culture were induced by enamel matrix protein derivative (EMD) for differentiation into cementoblast-like cells. MicroRNA chip technique was employed to screen the differentially expressed microRNAs in the cells during induced differentiation. The effect of inhibiting miR-30a on CTSK expression in the induced cells was examined using RT-PCR and Western blotting. Ceramic scaffolds coated with PDLSCs treated with EMD and transfected with the miR-30a inhibitor or a lentiviral vector for CTSK overexpression were prepared and implanted subcutaneously in nude mice, and 8 weeks later the cellular expressions of cementoblast markers CAP and CEMP-1 were detected with immunohistochemistry to verify whether CTSK participate in cementogenic differentiation of PDLSCs. The role of wnt signaling pathway in miR-30a-mediated regulation of CTSK expression was explored by examining CTSK protein expressions after blocking wnt signaling in PDLSCs. In PDLSCs with EMD-induced differentiation into cementoblast-like cells, multiple microRNAs exhibited differential expressions; and among them, miR-30a was specifically and significantly up-regulated (P < 0.05). Up-regulation of miR-30a obviously increased the expression of CTSK (P < 0.05) and promoted PDLSCs to form cementum-like tissues with high expressions of CAP and CEMP-1. The regulatory effect of miR-30a on CTSK expression was obviously attenuated after inhibiting wnt/β-catenin signaling pathway. EMD induces cementogenic differentiation of PDLSCs possibly by up-regulating the expression of miR-30a, which further activates the wnt/β-catenin signaling pathway to enhance the expression of CTSK.

Gene expression profile in functioning and non-functioning nodules of autonomous multinodular goiter from an area of iodine deficiency: unexpected common characteristics between the two entities

PurposeToxic multinodular goiter is a heterogeneous disease associated with hyperthyroidism frequently detected in areas with deficient iodine intake, and functioning and non-functioning nodules, characterized by increased proliferation but opposite functional activity, may coexist in the same gland. To understand the distinct molecular pathology of each entity present in the same gland, the gene expression profile was evaluated by using the Affymetrix technology.MethodsTotal RNA was extracted from nodular and healthy tissues of two patients and double-strand cDNA was synthesized. Biotinylated cRNA was obtained and, after chemical fragmentation, was hybridized on U133A and B arrays. Each array was stained and the acquired images were analyzed to obtain the expression levels of the transcripts. Both functioning and non-functioning nodules were compared versus healthy tissue of the corresponding patient.ResultsAbout 16% of genes were modulated in functioning nodules, while in non-functioning nodules only 9% of genes were modulated with respect to the healthy tissue. In functioning nodules of both patients and up-regulation of cyclin D1 and cyclin-dependent kinase inhibitor 1 was observed, suggesting the presence of a possible feedback control of proliferation. Complement components C1s, C7 and C3 were down-regulated in both types of nodules, suggesting a silencing of the innate immune response. Cellular fibronectin precursor was up-regulated in both functioning nodules suggesting a possible increase of endothelial cells. Finally, Frizzled-1 was down-regulated only in functioning nodules, suggesting a role of Wnt signaling pathway in the proliferation and differentiation of these tumors. None of the thyroid-specific gene was deregulated in microarray analysis.ConclusionIn conclusion, the main finding from our data is a similar modulation for both kinds of nodules in genes possibly implicated in thyroid growth.

Disheveled-associated activator of morphogenesis 2 promotes invasion of colorectal cancer by activating PAK1 and promoting MMP7 expression.

Disheveled-associated activator of morphogenesis (DAAM) family, including DAAM1 and DAAM2, is key regulators in Wnt signaling pathway. Although the oncogenic role of Wnt signaling pathway in colorectal cancer (CRC) was investigated in several lines, the expression and function of DAAM in CRC are still obscure. To investigate the expression and function of DAAM in CRC. DAAM1 and DAAM2 expression in high grade dysplasia (HGD), CRCs and corresponding adjacent tissues were detected with qRT-PCR and immunohistochemistry (IHC). The prognostic significance of DAAM1/2 were estimated with univariate and multivariate analyses. Moreover, the correlations between clinicopathological factors and DAAM were evaluated with the χ2 test. With experiments in vitro, we investigated the function of DAAM2 in CRC cell proliferation and invasion, and investigated the underlying mechanism of how DAAM2 facilitated CRC invasion. DAAM2, instead of DAAM1, was substantially up-regulated in CRCs compared with paired adjacent normal tissues and HGDs. The ratio of high DAAM1 and DAAM2 expression accounted for 44.83% and 46.31%, respectively. High DAAM2, instead of DAAM1, was a risk factor indicating an unfavorable prognosis of CRC. In multivariate analysis, high DAAM2 was identified as an independent prognostic biomarker of CRC predicting poor prognosis. With experiments in vitro, DAAM2 promoted invasion of CRC cells via activating PAK1 and promoting the expression of MMP7, suggesting an essential role of DAAM2 in CRC invasion. High expression of DAAM2, instead of DAAM1, indicated an unfavorable prognosis of CRC independently, which suggested that detecting DAAM2 can help define the high-risk patients. DAAM2 activated PAK1 and promoted MMP7 expression and facilitated the invasion of CRC cells, indicating that DAAM2 may be a potential drug target of CRC.

Transition between canonical to non-canonical Wnt signaling during interactions between mesenchymal stem cells and osteosarcomas

Background: Wnt signaling pathways are taking a part in regulation of cell fate decisions in normal and cancerous cells. In some cancer types, a transition from canonical to non-canonical Wnt signaling pathways was identified, a phenomenon, that in return led to increase proliferation, invasiveness and metastasis. Methods: In the current in vitro study we investigated the influence of MSCs, co-cultured in direct and indirect contact with OS cells, on the role of Wnt signaling pathways and tumor aggressiveness. Sub-populations were separated using Boyden chambers. Gene expression profiles were determined by qPCR. Results: The results revealed that interactions with MSCs increased migration and invasion capacities along with OS proliferation. Moreover, canonical Wnt signaling activity was low in OS, and co-culture with MSC. However, MSCs did not trigger a switch between the canonical to the no-canonical Wnt pathways. In addition, a more aggressive OS sub-population tend to undergo a transition towards the non-canonical pathway. Moreover, this aggressive subtype presented cancer stem-cells like characteristic. Conclusions: We submit that the progression in OS aggressiveness is attributed to a transition in Wnt signaling from canonical to non-canonical pathways, although MSCs are likely to take a part during the tumor progression, in the case of OS, they did not affect the Wnt switch. These complex tumor promoting interactions may be found in the natural and tumorigenic bone microenvironment. A better understanding of the molecular signaling mechanisms involved in the tumor development and metastasis may contribute to development of new cancer therapies.

CLL-016: WNT3 and LEF1 Expression Levels and Outcome of Chronic Lymphocytic Leukemia in Egyptian Patients

Context Chronic lymphocytic leukemia (CLL), a hematologic malignancy, characterized by progressive accumulation of mature B lymphocytes. The role of Wnt signaling pathway has been reported in CLL biogenesis. Lymphoid enhancer-binding factor-1 (LEF1), a mediator of this canonical pathway has been identified in CLL. Objective To analyze Wnt signaling pathway members (WNT3) and its key mediator LEF1 expression levels in CLL patients and to assess their potential role as markers of CLL outcome. Design An observational prospective study from February 2017 till February 2018. Setting It was carried out in the Hematology unit at Oncology Center Mansoura University (OCMU). Patients This study was carried out on 35 newly diagnosed CLL patients in comparison with 15 adult controls, they were M/F 14/16 (47/53%), median age 63. Interventions The patients were subjected to history taking, physical examination and laboratory investigations of CLL. Wnt3 gene and LEF1 expression levels in peripheral blood of untreated CLL mononuclear cells and normal healthy controls were determined by RT-PCR. Main outcome measures Our study demonstrated significant upregulation of both Wnt3 and LEF1 in CLL PBMNC in comparison to healthy controls (P Results WNT3 and LEF1 were significantly decreased in CLL patients with ECOG 2&3 P=0.023 and 0.007, respectively. Untreated CLL patients harboring 17p deletion expressed significantly low LEF1 (P=0.033). A significant positive association was observed between WNT3 and LEF1 levels (Spearman r=0.74, P Conclusions WNT3 and its key mediator LEF1 were shown to be overexpressed and activated in CLL cells in comparison to healthy persons. Raising the interest that antagonizing Wnt signaling in CLL may represent an effective treatment potential. Interestingly, low expression of both WNT3 and LEF1 were associated with shortened survival in CLL patients which trigger more studies on a larger patient cohort.

Exosomal miR-130a-3p regulates osteogenic differentiation of Human Adipose-Derived stem cells through mediating SIRT7/Wnt/β-catenin axis.

ObjectivesIt is of profound significance for clinical bone regeneration to clarify the specific molecular mechanism from which we found that osteogenic differentiation of adipose‐derived stem cells (ADSCs) will be probably promoted by exosomes.Materials and MethodsBy means of lentiviral transfection, miR‐130a‐3p overexpression and knockdown ADSCs were constructed. Alizarin Red S was used to detect the calcium deposits, and qPCR was used to detect osteogenesis‐related genes, to verify the effect of miR‐130a‐3p on the osteogenic differentiation of ADSCs. CCK‐8 was used to detect the effect of miR‐130a‐3p on the proliferation of ADSCs. The target binding between miR‐130a‐3p and SIRT7 was verified by dual‐luciferase reporter gene assay. Furthermore, the role of Wnt signalling pathway in the regulation of ADSCs osteogenesis and differentiation by miR‐130a‐3p was further verified by detecting osteogenic‐related genes and proteins and alkaline phosphatase activity.Results(a) Overexpression of miR‐130a‐3p can enhance the osteogenic differentiation of ADSCs while reducing protein and mRNA levels of SIRT7, a target of miR‐130a‐3p. (b) Our study further found that overexpression of miR‐130a‐3p leads to down‐regulation of SIRT7 expression with up‐regulation of Wnt signalling pathway‐associated protein. (c) Overexpression of miR‐130a‐3p inhibited proliferation of ADSCs, while knockdown promoted it.ConclusionsThe obtained findings indicate that exosomal miR‐130a‐3p can promote osteogenic differentiation of ADSCs partly by mediating SIRT7/Wnt/β‐catenin axis, which will hence promote the application of exosomal microRNA in the field of bone regeneration.