Wnt signaling: is the party in the nucleus?

Diagnostic utility of LEF1 and β-catenin in WNT pathway tumors with CTNNB1 mutation

OBJECTIVE

This study aimed to compare the expression of lymphoid enhancer factor 1 (LEF1) and β-catenin in basal cell adenoma (BA), desmoid-type fibromatosis (DF), and pancreatic solid pseudopapillary neoplasm (SPN) to evaluate their diagnostic utility in tumors associated with the WNT/β-catenin signaling pathway harboring the mutation of CTNNB1 gene 3 exon.

METHODS

Eighty tumor patients, including 26 BAs, 30 DFs, and 24 SPNs, were analyzed. Immunohistochemical staining was identified positive (nuclear staining of LEF1 and β-catenin in > 50% of tumor cells). The diagnostic rate of LEF1 alone, β-catenin alone, and their combination were compared for each tumor type and all patients.

RESULTS

Compared to β-catenin, when LEF1 alone was used for diagnosis, the diagnostic rate increased by 46.16% for BA, 16.67% for SPN, and 11.25% for all patients, but decreased by 23.34% for DF. The combined use of β-catenin and LEF1 significantly increased the diagnostic ratio in BA (46.16%), SPN (16.67%), and all patients (21.25%), but only marginally in DF (3.33%). In terms of all WNT pathway tumors with CTNNB1 gene mutation encompassed by our study, statistical analysis revealed no significant difference between LEF1 alone and β-catenin alone. However, their combined application was highly significant (P = 0.001) .

CONCLUSION

While β-catenin is commonly used as a marker for WNT pathway tumors, its variable expression and localization can be challenging for diagnosis. Our study emphasizes the importance of LEF1 as a complementary marker to β-catenin in diagnosing BA, DF, SPN, and other WNT pathway tumors activated by exon 3 CTNNB1 gene mutation. The combined use of LEF1 and β-catenin enhances diagnostic accuracy and may help the identification of these tumor types.

Bmal1 regulates the stemness and tumorigenesis of gliomas with the Wnt/β-catenin signaling pathway

BACKGROUND

The circadian rhythm gene Brain and Muscle Arnt-like1 (Bmal1) acts as a transcription factor and plays a crucial role in oncogenesis and embryonic development. Bmal1 is notably overexpressed in various tumors, including glioma. However, the precise mechanisms underlying the elevated Bmal1 expression in glioma malignancy remain unclear.

METHODS

This study employed multiple databases, including The Cancer Genome Atlas (TCGA), GTEx, and cBioportal, to analyze Bmal1 mRNA expression in gliomas, evaluate its prognostic significance, investigate transcriptome alterations, identify key signaling pathways associated with Bmal1, and examine its interaction with tumor stem cells. Additionally, experimental validation was performed to confirm Bmal1's regulatory effects on glioma stem cells.

RESULTS

Our analysis revealed differential Bmal1 expression across glioma grades and molecular subtypes. Moreover, Bmal1 significantly influences several tumor-related signaling pathways, notably the Mapk, Met, and Wnt pathways, and is actively involved with stem cells. A strong positive correlation was observed between Bmal1 and glioma stem cell markers, such as Nestin, Sox2, and Cd133. Experimental validation confirmed that Bmal1 promotes stem cell expansion and tumor progression via the Wnt/β-catenin pathway.

CONCLUSION

This study underscores the critical regulatory function of Bmal1 in glioma development. The interaction between Bmal1 and glioma stem cells appears to significantly impact glioma initiation and progression.

Polyphenols as Wnt/β-catenin pathway modulators: A promising strategy in clinical neurodegeneration

Polyphenols, a diverse group of naturally occurring compounds found in plants, have garnered significant attention for their potential therapeutic properties in treating neurodegenerative diseases (NDs). The Wnt/β-catenin (WβC) signaling pathway, a crucial player in neurogenesis, neuronal survival, and synaptic plasticity, is involved in several cellular mechanisms related to NDs. Dysregulation of this pathway is a hallmark in the development of various NDs. This study explores multiple polyphenolic compounds, such as flavonoids, stilbenes, lignans, and phenolic acids, and their potential to protect the nervous system. It provides a comprehensive analysis of their effects on the WβC pathway, elucidating their modes of action. The study highlights the dual function of polyphenols in regulating and protecting the nervous system, providing reassurance about the research benefits. This review provides a comprehensive analysis of the results obtained from both in vitro studies and in vivo research, shedding light on how these substances influence the various components of the pathway. The focus is mainly on the molecular mechanisms that allow polyphenols to reduce oxidative stress, inflammation, and apoptotic processes, ultimately improving the function and survival of neurons. This study aims to offer a thorough understanding of the potential of polyphenols in targeting the WβC signaling pathway, which could lead to the development of innovative therapeutic options for NDs.

Crosstalk between thyroid CSCs and immune cells: basic principles and clinical implications

Thyroid cancer has become the most common endocrine malignancy. Although the majority of differentiated thyroid cancers have a favorable prognosis, advanced thyroid cancers, iodine-refractory thyroid cancers, and highly malignant undifferentiated carcinomas still face a serious challenge of poor prognosis and even death. Cancer stem cells are recognized as one of the central drivers of tumor evolution, recurrence and treatment resistance. A fresh viewpoint on the oncological aspects of thyroid cancer, including proliferation, invasion, recurrence, metastasis, and therapeutic resistance, has been made possible by the recent thorough understanding of the defining and developing features as well as the plasticity of thyroid cancer stem cells (TCSCs). The above characteristics of TCSCs are complicated and regulated by cell-intrinsic mechanisms (including activation of key stem signaling pathways, somatic cell dedifferentiation, etc.) and cell-extrinsic mechanisms. The complex communication between TCSCs and the infiltrating immune cell populations in the tumor microenvironment (TME) is a paradigm for cell-extrinsic regulators. This review introduces the current advances in the studies of TCSCs, including the origin of TCSCs, the intrinsic signaling pathways regulating the stemness of TCSCs, and emerging biomarkers; We further highlight the underlying principles of bidirectional crosstalk between TCSCs and immune cell populations driving thyroid cancer progression, recurrence, or metastasis, including the specific mechanisms by which immune cells maintain the stemness and other properties of TCSCs and how TCSCs reshape the immune microenvironmental landscape to create an immune evasive and pro-tumorigenic ecological niche. Finally, we outline promising strategies and challenges for targeting key programs in the TCSCs-immune cell crosstalk process to treat thyroid cancer.

Pancancer analysis of the interactions between CTNNB1 and infiltrating immune cell populations

Recently, evidence has indicated that CTNNB1 is important in a variety of malignancies. However, how CTNNB1 interacts with immune cell infiltration remains to be further investigated. In this study, we focused on the correlations between CTNNB1 and tumorigenesis, tumor progression, mutation, phosphorylation, and prognosis via gene expression profiling interaction analysis; TIMER 2.0, cBioPortal, GTEx, CPTAC, and GEPIA2 database analyses; and R software. CTNNB1 mutations are most found in uterine endometrioid carcinoma and hepatocellular carcinoma. However, no CTNNB1 mutations were found to be associated with a poor prognosis. In addition, CTNNB1 DNA methylation levels were higher in normal tissues than in tumor tissues in cancer except for breast invasive carcinoma, which had higher methylation levels in tumor tissues. The phosphorylation level of the S675 and S191 sites of CTNNB1 was greater in the primary tumor tissues in the clear cell renal cell carcinoma, liver hepatocellular carcinoma, lung adenocarcinoma, pancreatic adenocarcinoma, and breast cancer datasets but not in the glioblastoma multiform dataset. As for, with respect to immune infiltration, CD8 + T-cell infiltration was negatively correlated with the expression of CTNNB1 in thymoma and uterine corpus endometrial carcinoma. The CTNNB1 level was found to be positively associated with the infiltration index of the corresponding fibroblasts in the TCGA tumors of colon adenocarcinoma, human papillomavirus-negative head and neck squamous cell carcinoma, mesothelioma, testicular germ cell tumor, and thymoma. We also identified the top CTNNB1-correlated genes in the TCGA projects and analyzed the expression correlation between CTNNB1 and selected target genes, including PPP4R2, RHOA, and SPRED1. Additionally, pathway enrichment suggested that NUMB is involved in the Wnt pathway. This study highlights the predictive role of CTNNB1 across cancers, suggesting that CTNNB1 might serve as a potential biomarker for the diagnosis and prognosis evaluation of various malignant tumors.

Integration of microbiome, metabolomics and transcriptome for in-depth understanding of berberine attenuates AOM/DSS-induced colitis-associated colorectal cancer

A type of colorectal cancer (CRC)，Colitis-associated colorectal cancer (CAC)， is closely associated with chronic inflammation and gut microbiota dysbiosis. Berberine (BBR) has a long history in the treatment of intestinal diseases, which has been reported to inhibit colitis and CRC. However, the mechanism of its action is still unclear. Here, this study aimed to explore the potential protective effects of BBR on azoxymethane (AOM)/dextransulfate sodium (DSS)-induced colitis and tumor mice, and to elucidate its potential molecular mechanisms by microbiota, genes and metabolic alterations. The results showed that BBR inhibited the gut inflammation and improved the function of mucosal barrier to ameliorate AOM/DSS-induced colitis. And BBR treatment significantly reduced intestinal tumor development and ki-67 expression of intestinal tissue along with promoted apoptosis. Through microbiota analysis based on the 16 S rRNA gene, we found that BBR treatment improved intestinal microbiota imbalance in AOM/DSS-induced colitis and tumor mice, which were characterized by an increase of beneficial bacteria, for instance Akkermanisa, Lactobacillus, Bacteroides uniformis and Bacteroides acidifaciens. In addition, transcriptome analysis showed that BBR regulated colonic epithelial signaling pathway in CAC mice particularly by tryptophan metabolism and Wnt signaling pathway. Notably, BBR treatment resulted in the enrichment of amino acids metabolism and microbiota-derived SCFA metabolites. In summary, our research findings suggest that the gut microbiota-amino acid metabolism-Wnt signaling pathway axis plays critical role in maintaining intestinal homeostasis, which may provide new insights into the inhibitory effects of BBR on colitis and colon cancer.

A Mouse Model for Conditional Expression of Activated β-Catenin in Epidermal Keratinocytes

We report the generation and characterization of the K5: CAT bigenic mouse in which the constitutively activated form of β-catenin (ΔN89 β-catenin) is conditionally expressed in cytokeratin-5 (K5) positive epidermal keratinocytes. Following short-term doxycycline intake during the telogen resting phase, the adult K5: CAT bigenic develops enlarged pilosebaceous units that expand deep into the dermis, an expansion usually observed during the anagen growth phase. Prolonged doxycycline treatment results in significant thickening and folding of the K5: CAT epidermis. During this persistent induction period, there is clear evidence of increased keratinocyte proliferation, particularly in the epidermal basal cell layer and the outer root sheath of the hair follicle. This unscheduled increase in cellular proliferation likely explains the decrease in hair density observed in the K5: CAT mouse following persistent doxycycline intake. Numerous hyperplastic endometrioid cysts, which display cornification toward their lumens, are also observed during this treatment period. Remarkably, de-induction of ΔN89 β-catenin expression through doxycycline withdrawal results in a marked reversal of the skin phenotype, suggesting that these morphological changes are dependent on continued signaling by β-catenin and/or its downstream molecular mediators. Joining a small group of mouse models for conditional β-catenin signaling, our K5: CAT mouse model will be particularly useful in identifying those molecular mediators of β-catenin that are responsible for initiating and maintaining these phenotypic responses in the K5: CAT skin. Such studies are predicted to shed more light on β-catenin signaling in epidermal epithelial morphogenesis, hair follicle cycling, and hair growth pathologies.

Prognostic impact of tumor location and gene expression profile in sporadic desmoid tumor

PURPOSE

Prognostic biomarkers remain necessary in sporadic desmoid tumor (DT) because the clinical course is unpredictable. DT location along with gene expression between thoracic and abdominal wall locations was analyzed.

METHOD

Sporadic DT patients (GEIS Registry) diagnosed between 1982 and 2018 who underwent upfront surgery were enrolled retrospectively in this study. The primary endpoint was relapse-free survival (RFS). Additionally, the gene expression profile was analyzed in DT localized in the thoracic or abdominal wall, harboring the most frequent CTNNB1 T41A mutation.

RESULTS

From a total of 454 DT patients, 197 patients with sporadic DT were selected. The median age was 38.2 years (1.8-89.1) with a male/female distribution of 33.5/66.5. Most of them harbored the CTNNB1 T41A mutation (71.6 %), followed by S45F (17.8 %) and S45P (4.1 %). A significant worse median RFS was associated with males (p = 0.019), tumor size ≥ 6 cm (p = 0.001), extra-abdominal DT location (p < 0.001) and the presence of CTNNB1 S45F mutation (p = 0.013). In the multivariate analysis, extra-abdominal DT location, CTNNB1 S45F mutation and tumor size were independent prognostic biomarkers for worse RFS. DTs harboring the CTNNB1 T41A mutation showed overexpression of DUSP1, SOCS1, EGR1, FOS, LIF, MYC, SGK1, SLC2A3, and IER3, and underexpression of BMP4, PMS2, HOXA9, and WISP1 in thoracic versus abdominal wall locations.

CONCLUSION

Sporadic DT location exhibits a different prognosis in terms of RFS favoring the abdominal wall compared to extra-abdominal sites. A differential gene expression profile under the same CTNNB1 T41A mutation is observed in the abdominal wall versus the thoracic wall, mainly affecting the Wnt/β-catenin, TGFβ, IFN, and TNF pathways.

The role of hydrogen sulfide regulation of ferroptosis in different diseases

Ferroptosis is a programmed cell death that relies on iron and lipid peroxidation. It differs from other forms of programmed cell death such as necrosis, apoptosis and autophagy. More and more evidence indicates that ferroptosis participates in many types of diseases, such as neurodegenerative diseases, ischemia-reperfusion injury, cardiovascular diseases and so on. Hence, clarifying the role and mechanism of ferroptosis in diseases is of great significance for further understanding the pathogenesis and treatment of some diseases. Hydrogen sulfide (H2S) is a colorless and flammable gas with the smell of rotten eggs. Many years ago, H2S was considered as a toxic gas. however, in recent years, increasing evidence indicates that it is the third important gas signaling molecule after nitric oxide and carbon monoxide. H2S has various physiological and pathological functions such as antioxidant stress, anti-inflammatory, anti-apoptotic and anti-tumor, and can participate in various diseases. It has been reported that H2S regulation of ferroptosis plays an important role in many types of diseases, however, the related mechanisms are not fully clear. In this review, we reviewed the recent literature about the role of H2S regulation of ferroptosis in diseases, and analyzed the relevant mechanisms, hoping to provide references for future in-depth researches.

Down-regulated expression of TIPE3 inhibits malignant progression of non-small cell lung cancer via Wnt signaling

Non-small cell lung cancer (NSCLC) accounts for approximately 80 % of all lung cancers with a low five-year survival rate. Therefore, the mechanistic pathways and biomarkers of NSCLC must be explored to elucidate its pathogenesis. In this study, we examined TIPE3 expression in NSCLC cells and investigated the molecular mechanisms underlying NSCLC regulation in vivo and in vitro. We collected tissue samples from patients with NSCLC to examine TIPE3 expression and its association with patient metastasis and prognosis. Furthermore, we evaluated the expression level of TIPE3 in NSCLC cells. Cell lines with the highest expression were selected for molecular mechanism experiments, and animal models were established for in vivo verification. The results showed that TIPE3 was significantly increased in patients with NSCLC, and this increased expression was associated with tumor metastasis and patient prognosis. TIPE3 knockdown inhibited proliferation, migration, invasion, EMT, angiogenesis, and tumorsphere formation in NSCLC cells. Moreover, it reduced the metabolic levels of tumor cells. However, overexpression of TIPE3 has the opposite effect. The in vivo results showed that TIPE3 knockdown reduced tumor volume, weight, and metastasis. Furthermore, the results showed that TIPE3 may inhibit malignant progression of NSCLC via the regulation of Wnt/β-catenin expression. These findings suggest that TIPE3 is significantly elevated in patients with NSCLC and that downregulation of TIPE3 can suppress the malignant progression of NSCLC, which could serve as a potential diagnostic and treatment strategy for NSCLC.

LSD1 controls a nuclear checkpoint in Wnt/β-Catenin signaling to regulate muscle stem cell self-renewal

The Wnt/β-Catenin pathway plays a key role in cell fate determination during development and in adult tissue regeneration by stem cells. These processes involve profound gene expression and epigenome remodeling and linking Wnt/β-Catenin signaling to chromatin modifications has been a challenge over the past decades. Functional studies of the lysine demethylase LSD1/KDM1A converge to indicate that this epigenetic regulator is a key regulator of cell fate, although the extracellular cues controlling LSD1 action remain largely unknown. Here we show that β-Catenin is a substrate of LSD1. Demethylation by LSD1 prevents β-Catenin degradation thereby maintaining its nuclear levels. Consistently, in absence of LSD1, β-Catenin transcriptional activity is reduced in both MuSCs and ESCs. Moreover, inactivation of LSD1 in mouse muscle stem cells and embryonic stem cells shows that LSD1 promotes mitotic spindle orientation via β-Catenin protein stabilization. Altogether, by inscribing LSD1 and β-Catenin in the same molecular cascade linking extracellular factors to gene expression, our results provide a mechanistic explanation to the similarity of action of canonical Wnt/β-Catenin signaling and LSD1 on stem cell fate.

Epigenetic regulation in cancer

Epigenetic modifications are defined as heritable changes in gene activity that do not involve changes in the underlying DNA sequence. The oncogenic process is driven by the accumulation of alterations that impact genome's structure and function. Genetic mutations, which directly disrupt the DNA sequence, are complemented by epigenetic modifications that modulate gene expression, thereby facilitating the acquisition of malignant characteristics. Principals among these epigenetic changes are shifts in DNA methylation and histone mark patterns, which promote tumor development and metastasis. Notably, the reversible nature of epigenetic alterations, as opposed to the permanence of genetic changes, positions the epigenetic machinery as a prime target in the discovery of novel therapeutics. Our review delves into the complexities of epigenetic regulation, exploring its profound effects on tumor initiation, metastatic behavior, metabolic pathways, and the tumor microenvironment. We place a particular emphasis on the dysregulation at each level of epigenetic modulation, including but not limited to, the aberrations in enzymes responsible for DNA methylation and histone modification, subunit loss or fusions in chromatin remodeling complexes, and the disturbances in higher-order chromatin structure. Finally, we also evaluate therapeutic approaches that leverage the growing understanding of chromatin dysregulation, offering new avenues for cancer treatment.

Great potential of renal progenitor cells in kidney: From the development to clinic

The mammalian renal organ represents a pinnacle of complexity, housing functional filtering units known as nephrons. During embryogenesis, the depletion of niches containing renal progenitor cells (RPCs) and the subsequent incapacity of adult kidneys to generate new nephrons have prompted the formulation of protocols aimed at isolating residual RPCs from mature kidneys and inducing their generation from diverse cell sources, notably pluripotent stem cells. Recent strides in the realm of regenerative medicine and the repair of tissues using stem cells have unveiled critical signaling pathways essential for the maintenance and generation of human RPCs in vitro. These findings have ushered in a new era for exploring novel strategies for renal protection. The present investigation delves into potential transcription factors and signaling cascades implicated in the realm of renal progenitor cells, focusing on their protection and differentiation. The discourse herein elucidates contemporary research endeavors dedicated to the acquisition of progenitor cells, offering crucial insights into the developmental mechanisms of these cells within the renal milieu and paving the way for the formulation of innovative treatment modalities.

Recent Advances in the Targeting of Head and Neck Cancer Stem Cells

Head and neck squamous cell carcinoma (HNSCC) is a very heterogeneous cancer with a poor overall response to therapy. One of the reasons for this therapy resistance could be cancer stem cells (CSCs), a small population of cancer cells with self-renewal and tumor-initiating abilities. Tumor cell heterogeneity represents hurdles for therapeutic elimination of CSCs. Different signaling pathway activations, such as Wnt, Notch, and Sonic-Hedgehog (SHh) pathways, lead to the expression of several cancer stem factors that enable the maintenance of CSC features. Identification and isolation of CSCs are based either on markers (CD133, CD44, and aldehyde dehydrogenase (ALDH)), side populations, or their sphere-forming ability. A key challenge in cancer therapy targeting CSCs is overcoming chemotherapy and radiotherapy resistance. However, in novel therapies, various approaches are being employed to address this hurdle such as targeting cell surface markers, other stem cell markers, and different signaling or metabolic pathways, but also, introducing checkpoint inhibitors and natural compounds into the therapy can be beneficial.

The role of myo-inositol supplement in assisted reproductive techniques

Assisted reproductive techniques can help many infertile couples conceive. Therefore, there is a need for an effective method to overcome the widespread problems of infertile men and women. Oocyte and sperm quality can increase the chances of successful in vitro fertilisation. The maturation environment in which gametes are present can affect their competency for fertilisation. It is well established that myo-inositol (MI) plays a pivotal role in reproductive physiology. It participates in cell membrane formation, lipid synthesis, cell proliferation, cardiac regulation, metabolic alterations, and fertility. This molecule also acts as a direct messenger of insulin and improves glucose uptake in various reproductive tissues. Evidence suggests that MI regulates events such as gamete maturation, fertilisation, and embryo growth through intracellular Ca2 + release and various signalling pathways. In addition to the in-vivo production of MI from glucose in the reproductive organs, its synthesis by in vitro-cultured sperm and follicles has also been reported. Therefore, MI is suggested as a therapeutic approach to maintain sperm and oocyte health in men and women with reproductive disorders and individuals of reproductive age.

Design, synthesis and anti-osteosarcoma activity study of novel pyrido[2,3-d]pyrimidine derivatives by inhibiting DKK1-Wnt/β-catenin pathway

Osteosarcoma is a common primary malignant bone tumor in adolescents. Wnt/β-catenin has been proved to play a pro-oncogenic role and was overactivated in osteosarcoma. Therefore, this pathway has become an interesting therapeutic target for osteosarcoma. Herein we report the design, synthesis and biological activities of a series of novel pyrido[2,3-d]pyrimidine derivatives based on our previous work. Among these, the representative compound 2-{[1,3-dimethyl-7-(4-methylpiperazin-1-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin-5-yl]amino}-N-[4-(trifluoromethoxy)phenyl]acetamide (7m) has exhibited good antiproliferative activity towards 143B and MG63 cells with good selectivity over non-cancerous HSF cells. In the assay of Ca2+ concentration, the compound 7m increased the intracellular Ca2+ concentration in 143B cells. In addition, the expression of DKK1 increased, and that of p-β-catenin decreased by 7m treatment. Finally, the Hoechst 33,342 staining, Annexin-FITC/PI staining and mitochondrial fluorescence staining have clearly demonstrated that compound 7m induced apoptosis in 143B cells.

The Role of Traditional Chinese Medicine Natural Products in β-Amyloid Deposition and Tau Protein Hyperphosphorylation in Alzheimer's Disease

Alzheimer's disease is a prevalent form of dementia among elderly individuals and is characterized by irreversible neurodegeneration. Despite extensive research, the exact causes of this complex disease remain unclear. Currently available drugs for Alzheimer's disease treatment are limited in their effectiveness, often targeting a single aspect of the disease and causing significant adverse effects. Moreover, these medications are expensive, placing a heavy burden on patients' families and society as a whole. Natural compounds and extracts offer several advantages, including the ability to target multiple pathways and exhibit high efficiency with minimal toxicity. These attributes make them promising candidates for the prevention and treatment of Alzheimer's disease. In this paper, we provide a summary of the common natural products used in Chinese medicine for different pathogeneses of AD. Our aim is to offer new insights and ideas for the further development of natural products in Chinese medicine and the treatment of AD.

Wnt signaling in periodontitis

OBJECTIVE

This study aimed to evaluate the Wnt/β-catenin signaling pathway activity in gingival samples obtained from patients with periodontitis.

MATERIALS AND METHODS

Fifteen patients with stage III grade B (SIIIGB) and eleven with stage III grade C (SIIIGC) periodontitis were included and compared to 15 control subjects. β-Catenin, Wnt 3a, Wnt 5a, and Wnt 10b expressions were evaluated by Q-PCR. Topographic localization of tissue β-catenin, Wnt 5a, and Wnt 10b was measured by immunohistochemical analysis. TNF-α was used to assess the inflammatory state of the tissues, while Runx2 was used as a mediator of active destruction.

RESULTS

Wnt 3a, Wnt 5a, and Wnt 10b were significantly higher in gingival tissues in both grades of stage 3 periodontitis compared to the control group (p < 0.05). β-Catenin showed intranuclear staining in connective tissue in periodontitis, while it was confined to intracytoplasmic staining in epithelial tissue and the cell walls in the control group. Wnt5a protein expression was elevated in periodontitis, with the most intense staining observed in the connective tissue of SIIIGC samples. Wnt10b showed the highest density in the connective tissue of patients with periodontitis.

CONCLUSIONS

Our findings suggested that periodontal inflammation disrupts the Wnt/β-catenin signaling pathway.

CLINICAL RELEVANCE

Periodontitis disrupts Wnt signaling in periodontal tissues in parallel with tissue inflammation and changes in morphology. This change in Wnt-related signaling pathways that regulate tissue homeostasis in the immunoinflammatory response may shed light on host-induced tissue destruction in the pathogenesis of the periodontal disease.

Genomic landscape and expression profile of consensus molecular subtype four of colorectal cancer

Background

Compared to other subtypes, the CMS4 subtype is associated with lacking of effective treatments and poorer survival rates.

Methods

A total of 24 patients with CRC were included in this study. DNA and RNA sequencing were performed to acquire somatic mutations and gene expression, respectively. MATH was used to quantify intratumoral heterogeneity. PPI and survival analyses were performed to identify hub DEGs. Reactome and KEGG analyses were performed to analyze the pathways of mutated or DEGs. Single-sample gene set enrichment analysis and Xcell were used to categorize the infiltration of immune cells.

Results

The CMS4 patients had a poorer PFS than CMS2/3. CTNNB1 and CCNE1 were common mutated genes in the CMS4 subtype, which were enriched in Wnt and cell cycle signaling pathways, respectively. The MATH score of CMS4 subtype was lower. SLC17A6 was a hub DEG. M2 macrophages were more infiltrated in the tumor microenvironment of CMS4 subtype. The CMS4 subtype tended to have an immunosuppressive microenvironment.

Conclusion

This study suggested new perspectives for exploring therapeutic strategies for the CMS4 subtype CRC.

H3K27me3 Inactivates SFRP1 to Promote Cell Proliferation via Wnt/β-Catenin Signaling Pathway in Esophageal Squamous Cell Carcinoma

BACKGROUND

Histone methylations are generally considered to play an important role in multiple cancers by regulating cancer-related genes.

AIMS

This study aims to investigate the effects of H3K27me3-mediated inactivation of tumor suppressor gene SFRP1 and its function in esophageal squamous cell carcinoma (ESCC).

METHODS

We performed ChIP-seq on H3K27me3-enriched genomic DNA fragments in ESCC cells to screen out tumor suppressor genes that may be regulated by H3K27me3. ChIP-qPCR and Western blot were employed to explore the regulating mechanisms between H3K27me3 and SFRP1. Expression level of SFRP1 was assessed by quantitative real-time polymerase chain reaction (q-PCR) in 29 pairs of ESCC surgical samples. SFRP1 function in ESCC cells were detected by cell proliferation assay, colony formation assay and wound-healing assay.

RESULTS

Our results indicated that H3K27me3 was widely distributed in the genome of ESCC cells. Specifically, we found that H3K27me3 deposited on the upstream region of SFRP1 promoter and inactivated SFRP1 expression. Furthermore, we found SFRP1 was significantly down-regulated in ESCC tissues compared with the adjacent non-tumor tissues, and SFRP1 expression was significantly associated with TNM stage and lymph node metastasis. In vitro cell-based assay indicated that over-expression of SFRP1 significantly suppressed cell proliferation and negatively correlated with the expression of β-catenin in the nucleus.

CONCLUSIONS

Our study revealed a previously unrecognized finding that H3K27me3-mediated SFRP1 inhibit the cell proliferation of ESCC through inactivation of Wnt/β-catenin signaling pathway.

Traditional Chinese medicine for colorectal cancer treatment: potential targets and mechanisms of action

Colorectal cancer (CRC) is a disease with complex pathogenesis, it is prone to metastasis, and its development involves abnormalities in multiple signaling pathways. Surgery, chemotherapy, radiotherapy, target therapy, and immunotherapy remain the main treatments for CRC, but improvement in the overall survival rate and quality of life is urgently needed. Traditional Chinese medicine (TCM) has a long history of preventing and treating CRC. It could affect CRC cell proliferation, apoptosis, cell cycle, migration, invasion, autophagy, epithelial-mesenchymal transition, angiogenesis, and chemoresistance by regulating multiple signaling pathways, such as PI3K/Akt, NF-κB, MAPK, Wnt/β-catenin, epidermal growth factor receptors, p53, TGF-β, mTOR, Hedgehog, and immunomodulatory signaling pathways. In this paper, the main signaling pathways and potential targets of TCM and its active ingredients in the treatment of CRC were systematically summarized, providing a theoretical basis for treating CRC with TCM and new ideas for further exploring the pathogenesis of CRC and developing new anti-CRC drugs.

New Emerging Biomarkers for Bone Disease: Sclerostin and Dickkopf-1 (DKK1)

A healthy skeleton depends on a continuous renewal and maintenance of the bone tissue. The process of bone remodeling is highly controlled and consists of a fine-tuned balance between bone formation and bone resorption. Biochemical markers of bone turnover are already in use for monitoring diseases and treatment involving the skeletal system, but novel biomarkers reflecting specific biological processes in bone and interacting tissues may prove useful for diagnostic, prognostic, and monitoring purposes. The Wnt-signaling pathway is one of the most important pathways controlling bone metabolism and consequently the action of inhibitors of the pathway such as sclerostin and Dickkopf-related protein 1 (DKK1) have crucial roles in controlling bone formation and resorption. Thus, they might be potential markers for clinical use as they reflect a number of physiological and pathophysiological events in bone and in the cross-talk with other tissues in the human body. This review focuses on the clinical utility of measurements of circulating sclerostin and DKK1 levels based on preanalytical and analytical considerations and on evidence obtained from published clinical studies. While accumulating evidence points to clear associations with a number of disease states for the two markers, and thus, the potential for especially sclerostin as a biochemical marker that may be used clinically, the lack of standardization or harmonization of the assays still hampers the clinical utility of the markers.

Novel Insights into the Role of Kras in Myeloid Differentiation: Engaging with Wnt/β-Catenin Signaling

Cells of the HL-60 myeloid leukemia cell line can be differentiated into neutrophil-like cells by treatment with dimethyl sulfoxide (DMSO). The molecular mechanisms involved in this differentiation process, however, remain unclear. This review focuses on the differentiation of HL-60 cells. Although the Ras proteins, a group of small GTP-binding proteins, are ubiquitously expressed and highly homologous, each has specific molecular functions. Kras was shown to be essential for normal mouse development, whereas Hras and Nras are not. Kras knockout mice develop profound hematopoietic defects, indicating that Kras is required for hematopoiesis in adults. The Wnt/β-catenin signaling pathway plays a crucial role in regulating the homeostasis of hematopoietic cells. The protein β-catenin is a key player in the Wnt/β-catenin signaling pathway. A great deal of evidence shows that the Wnt/β-catenin signaling pathway is deregulated in malignant tumors, including hematological malignancies. Wild-type Kras acts as a tumor suppressor during DMSO-induced differentiation of HL-60 cells. Upon DMSO treatment, Kras translocates to the plasma membrane, and its activity is enhanced. Inhibition of Kras attenuates CD11b expression. DMSO also elevates levels of GSK3β phosphorylation, resulting in the release of unphosphorylated β-catenin from the β-catenin destruction complex and its accumulation in the cytoplasm. The accumulated β-catenin subsequently translocates into the nucleus. Inhibition of Kras attenuates Lef/Tcf-sensitive transcription activity. Thus, upon treatment of HL-60 cells with DMSO, wild-type Kras reacts with the Wnt/β-catenin pathway, thereby regulating the granulocytic differentiation of HL-60 cells. Wild-type Kras and the Wnt/β-catenin signaling pathway are activated sequentially, increasing the levels of expression of C/EBPα, C/EBPε, and granulocyte colony-stimulating factor (G-CSF) receptor.

G protein subunit gamma 5 promotes the proliferation, metastasis and glycolysis of breast cancer cells through the Wnt/β-catenin pathway

GNG5 is suggested to exert a critical effect on tumor development in human beings; however, its function and related mechanism within breast cancer (BC) are still unclear. In this regard, the present work focused on identifying and evaluating GNG5's function and revealing its possible molecular mechanism. Subcutaneous tumorigenesis model of nude mice and in-vitro cell model was established. The relationship between GNG5 expression and BC was studied through knockdown and overexpression experiments. The proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of liver cancer cell lines overexpressing or silencing GNG5 were detected. Furthermore, the pathway mechanism of GNG5 was evaluated at the molecular level and was performed to further verify the possible targets and mechanisms of action. In comparison with that in normal tissue, GNG5 level within BC tissue was higher. In addition, GNG5 overexpression stimulated BC cell proliferation, invasion, migration and EMT. BC cells with reduced GNG5 expression exhibited significant decreases in glucose uptake, lactate levels, and ATP concentrations. In addition, GNG5 knockdown inhibited Wnt/β-catenin signaling. This study indicates that GNG5 may generate a vital function in BC. The results of the current work demonstrated GNG5's effect on BC pathological process, also providing a reference for developing new targeted therapies for BC.

The Critical Gene Screening to Prevent Chromophobe Cell Renal Carcinoma Metastasis through TCGA and WGCNA

Common chromophobe renal cell carcinoma (chRCC) has a good prognosis when cured by surgery. However, clinical practice shows that a small number of patients with chRCC will produce metastasis, and the prognosis after metastasis is poor. In this regard, we try to find potential biological targets to prevent CRCC metastasis. In this experiment, we analyzed the clinical traits and gene expression data of chRCC samples which were provided by the TCGA database by the WGCNA method. On this basis, we selected MEtan, a module with a significant positive correlation with the M phase of chRCC, for subsequent analysis. The MEtan module genes in the biological process of chRCC were mainly related to steroid metabolic process, cholesterol metabolic process and STEM cell differentiation. KEGG analysis showed that these genes were mainly enriched in cancer-related signaling pathways, such as Neuroactive Ligand−receptor interaction, cAMP signaling pathway, and Wnt signaling pathway. Subsequently, we mapped the PPI interaction network and screened the key gene beta-arrestin 2 (ARRB2). Expression analysis showed that there was a significantly increased expression of ARRB2 in chRCC patients in comparison to the normal group. Expression survival analysis indicated that ARRB2 was inversely associated with overall survival. We firmly believe that the key genes identified in this study would be able to provide new clues and research basis for the treatment of chRCC.

Genomic Landscape of Metastatic Lymph Nodes and Primary Tumors in Non-Small-Cell Lung Cancer

Objective: To investigate the genetic mutation characteristics of non-small cell lung cancers (NSCLC) with and without lymph node metastasis.

Methods: Primary lesions and metastatic lymph node lesions of 36 Chinese NSCLC patients were tested for somatic mutations, tumor mutation burden, phylogenetic and clonal evolutional analysis using a 1021-gene panel by next-generation sequencing (NGS) with an average sequencing depth of 671X.

Results: In this study, eighteen patients with lung adenocarcinoma (LUAD) and 18 with lung squamous cell carcinoma (LUSC) were included. Different groups had distinct characteristics of gene mutations. CTNNB1 gene mutations were only present in Nome_LC LUAD patients (p &lt; 0.05). ARID1A mutation was however the only gene with significant alterations (p &lt; 0.05) in Nome_LC in LUSC. Phylogenetic trees of mutated genes were also constructed. Linear and parallel evolutions of metastatic lymph nodes were observed both in LUAD and LUSC.

Conclusion: LUSC exhibited more genetic mutations than LUAD. Intriguingly, there was significant difference in gene mutations between Meta_LC and Nome_LC. CTNNB1 gene alteration was the key mutation in LUAD that seems to promote proliferation of the tumor and then determine T stage. On the other hand, proliferation of the tumor was characterized by ARID1A missense mutation in LUSC, thus influencing the T stage as well. Lymph node metastasis could display both linear and parallel evolutionary characteristics in NSCLC. Different metastatic lymph nodes might have exactly the same or different mutated genes, underlining the heterogeneous genomic characteristics of these cancer types.

An Extensive Review on Preclinical and Clinical Trials of Oncolytic Viruses Therapy for Pancreatic Cancer

Chemotherapy resistance and peculiar tumor microenvironment, which diminish or mitigate the effects of therapies, make pancreatic cancer one of the deadliest malignancies to manage and treat. Advanced immunotherapies are under consideration intending to ameliorate the overall patient survival rate in pancreatic cancer. Oncolytic viruses therapy is a new type of immunotherapy in which a virus after infecting and lysis the cancer cell induces/activates patients’ immune response by releasing tumor antigen in the blood. The current review covers the pathways and molecular ablation that take place in pancreatic cancer cells. It also unfolds the extensive preclinical and clinical trial studies of oncolytic viruses performed and/or undergoing to design an efficacious therapy against pancreatic cancer.

Antitumor Activity of Rutaecarpine in Human Colorectal Cancer Cells by Suppression of Wnt/β-Catenin Signaling

Alkaloids derived from natural products have been traditionally used to treat various diseases, including cancers. Rutaecarpine (1), a β-carboline-type alkaloid obtained from Evodia rutaecarpa, has been previously reported as an anti-inflammatory agent. Nonetheless, its anticancer activity and the underlying molecular mechanisms remain to be explored. In the procurement of Wnt/β-catenin inhibitors from natural alkaloids, 1 was found to exhibit activity against the Wnt/β-catenin-response reporter gene. Since the abnormal activation of Wnt/β-catenin signaling is highly involved in colon carcinogenesis, the antitumor activity and molecular mechanisms of 1 were investigated in colorectal cancer (CRC) cells. The antiproliferative activity of 1 was associated with the suppression of the Wnt/β-catenin-mediated signaling pathway and its target gene expression in human CRC cells. 1 also induced G₀/G₁ cell cycle arrest and apoptotic cell death, and the antimigration and anti-invasion potential of 1 was confirmed through epithelial-mesenchymal transition biomarker inhibition by the regulation of Wnt signaling. The antitumor activity of 1 was supported in an Ls174T-implanted xenograft mouse model via Wnt target gene regulation. Overall, these findings suggest that targeting the Wnt/β-catenin signaling pathway by 1 is a promising therapeutic option for the treatment of human CRC harboring β-catenin mutation.

Adipose-Derived Stem Cells Exosomes Improve Fat Graft Survival by Promoting Prolipogenetic Abilities through Wnt/β-Catenin Pathway

Autologous fat grafting has been widely used in plastic surgery in recent years, but the unstable retention of fat graft has always been a key clinical problem. Adipose tissue has poor tolerant to ischemia, so the transplanted adipose tissue needs to rebuild blood supply at an early stage in order to survive stably. Our previous study has found that comparing to human foreskin fibroblast exosome (HFF-Exo), human adipose-derived stem cells exosome (hADSC-Exo) can significantly improve the proliferation of vascular endothelial cells and the angiogenic effect of artificial dermal preconstructed flaps. Therefore, the ability of hADSC-Exo to improve the retention of adipose grafts and its potential regenerative mechanism aroused our strong interest. In this study, we applied hADSC-Exo and HFF-Exo to adipose grafts and explored the potential regeneration mechanism through various means such as bioinformatics, immunofluorescence, immunohistochemistry, and adipogenic differentiation. The results showed that hADSC-Exo can significantly promote grafts angiogenesis and adipogenic differentiation of ADSC to improve the retention of fat grafts and may downregulate the Wnt/β-catenin signaling pathway to promote the adipogenic differentiation. In summary, our results provide a theoretical basis for the clinical translation of hADSC-Exo in fat grafting.

Functions and clinical significance of mechanical tumor microenvironment: cancer cell sensing, mechanobiology and metastasis

Dynamic and heterogeneous interaction between tumor cells and the surrounding microenvironment fuels the occurrence, progression, invasion, and metastasis of solid tumors. In this process, the tumor microenvironment (TME) fractures cellular and matrix architecture normality through biochemical and mechanical means, abetting tumorigenesis and treatment resistance. Tumor cells sense and respond to the strength, direction, and duration of mechanical cues in the TME by various mechanotransduction pathways. However, far less understood is the comprehensive perspective of the functions and mechanisms of mechanotransduction. Due to the great therapeutic difficulties brought by the mechanical changes in the TME, emerging studies have focused on targeting the adverse mechanical factors in the TME to attenuate disease rather than conventionally targeting tumor cells themselves, which has been proven to be a potential therapeutic approach. In this review, we discussed the origins and roles of mechanical factors in the TME, cell sensing, mechano‐biological coupling and signal transduction, in vitro construction of the tumor mechanical microenvironment, applications and clinical significance in the TME.

Therapeutic Effects of Self-Assembled Tetrahedral Framework Nucleic Acids on Liver Regeneration in Acute Liver Failure

Liver failure is a serious disease that is characterized by global hepatocyte necrosis. Hepatocyte proliferation and liver regeneration are critically important for the success of treatments for liver disease. Tetrahedral framework nucleic acids (TFNAs), which are widely used antioxidants and anti-inflammatory nanomaterials, activate multiple proliferation and prosurvival pathways. Therefore, the effects of a TFNA on hepatocyte proliferation and liver regeneration in mouse livers injured by 70% partial hepatectomy (PHx), acetaminophen overdose, and carbon tetrachloride were explored in this study. The TFNA, which was successfully self-assembled from four specifically designed ssDNAs, entered the body quickly and was taken up effectively by hepatocytes in the liver and could eventually be cleared by the kidneys. The TFNA promoted hepatocyte proliferation in vitro by activating the Notch and Wnt signaling pathways. In the three in vivo mouse models of liver injury, the TFNA attenuated the injuries and enhanced liver regeneration by regulating the cell cycle and the P53 signaling pathway. Therefore, by promoting hepatocyte proliferation and enhancing liver regeneration, the TFNA shows potential as an effective therapeutic agent for treating acute liver injury induced by 70% PHx and other factors, thereby preventing the progression to acute liver failure and reducing the associated mortality rate.

Wnt Signaling Pathway: A Comprehensive Review

Wnt signaling is an evolutionary cell-to-cell coordination mechanism and it is highly critical for a variety of physiological processes of an organism's body, including stem cell regeneration, proliferation, division, migration, polarity of a cell, determining fate of the cell and specification of neural crest, neural symmetry and morphogenesis. Wnts are extracellular secreted glycol proteins, consisted of a family of 19 human proteins that represent the complex nature of the regulatory structure and physiological efficiency of signaling. Moreover, a Wnt/β-catenin-dependent pathway and the β-catenin-independent pathway that is further classified into the Planar Cell Polarity and Wnt/Ca²⁺ pathways have been established as key signaling nodes downstream of the frizzled (Fz/Fzd) receptor, and these nodes are extensively analyzed at biochemical and molecular levels. Genetic and epigenetic activities that ultimately characterize the pathway and its subsequent responses contribute to Wnt-β-catenin signaling pathway hypo or hyper-activation and is associated with the variety of human disorders progression most significantly cancers. Recognizing how this mechanism operates is crucial to the advancement of cancer prevention therapies or regenerative medicine methods. This article is protected by copyright. All rights reserved.

A pyridinium‑type fullerene derivative suppresses primary effusion lymphoma cell viability via the downregulation of the Wnt signaling pathway through the destabilization of β‑catenin

Primary effusion lymphoma (PEL) is defined as a rare subtype of non-Hodgkin's B cell lymphoma, which is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients. PEL is an aggressive type of lymphoma and is frequently resistant to conventional chemotherapeutics. Therefore, the discovery of novel drug candidates for the treatment of PEL is of utmost importance. In order to discover potential novel anti-tumor compounds against PEL, the authors previously developed a pyrrolidinium-type fullerene derivative, 1,1,1′,1′-tetramethyl [60]fullerenodipyrrolidinium diiodide (derivative #1), which induced the apoptosis of PEL cells via caspase-9 activation. In the present study, the growth inhibitory effects of pyrrolidinium-type (derivatives #1 and #2), pyridinium-type (derivatives #3 and #5 to #9) and anilinium-type fullerene derivatives (derivative #4) against PEL cells were evaluated. This analysis revealed a pyridinium-type derivative (derivative #5; 3- 5′-(etho-xycarbonyl)-1′,5′-dihydro-2′H-[5,6]fullereno-C₆₀-I_h-[1,9-c]pyrrol-2′-yl]-1-methylpyridinium iodide), which exhibited antitumor activity against PEL cells via the downregulation of Wnt/β-catenin signaling. Derivative #5 suppressed the viability of KSHV-infected PEL cells compared with KSHV-uninfected B-lymphoma cells. Furthermore, derivative #5 induced the destabilization of β-catenin and suppressed β-catenin-TCF4 transcriptional activity in PEL cells. It is known that the constitutive activation of Wnt/β-catenin signaling is essential for the growth of KSHV-infected cells. The Wnt/β-catenin activation in KSHV-infected cells is mediated by KSHV latency-associated nuclear antigen (LANA). The data demonstrated that derivative #5 increased β-catenin phosphorylation, which resulted in β-catenin polyubiquitination and subsequent degradation. Thus, derivative #5 overcame LANA-mediated β-catenin stabilization. Furthermore, the administration of derivative #5 suppressed the development of PEL cells in the ascites of SCID mice with tumor xenografts derived from PEL cells. On the whole, these findings provide evidence that the pyridinium-type fullerene derivative #5 exhibits antitumor activity against PEL cells in vitro and in vivo. Thus, derivative #5 may be utilized as a novel therapeutic agent for the treatment of PEL.

Only the Co-Transcriptional Activity of β-Catenin Is Required for the Local Regulatory Effects in Hypertrophic Chondrocytes on Developmental Bone Modeling

In hypertrophic chondrocytes, β-catenin has two roles. First, it locally suppresses the differentiation of osteoclasts at the chondro-osseous junction by maintaining the pro-osteoclastic factor receptor activator of NF-κB ligand (RANKL) at low levels. Second, it promotes the differentiation of osteoblast-precursors from chondrocytes. Yet, β-catenin is a dual-function protein, which can either participate in cell-cell adherens junctions or serve as a transcriptional co-activator in canonical Wnt signaling interacting with T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors. Hence, whenever studying tissue-specific requirements of β-catenin using a conventional conditional knockout approach, the functional mechanisms underlying the defects in the conditional mutants remain ambiguous. To decipher mechanistically which of the two molecular functions of β-catenin is required in hypertrophic chondrocytes, we used different approaches. We analyzed the long bones of newborn mice carrying either the null-alleles of Lef1 or Tcf7, or mice in which Tcf7l2 was conditionally deleted in the hypertrophic chondrocytes, as well as double mutants for Lef1 and Tcf7l2, and Tcf7 and Tcf7l2. Furthermore, we analyzed Ctnnb1 mutant newborns expressing a signaling-defective allele that retains the cell adhesion function in hypertrophic chondrocytes. None of the analyzed Tcf/Lef single or double mutants recapitulated the previously published phenotype upon loss of β-catenin in hypertrophic chondrocytes. However, using this particular Ctnnb1 allele, maintaining cell adhesion function, we show that it is the co-transcriptional activity of β-catenin, which is required in hypertrophic chondrocytes to suppress osteoclastogenesis and to promote chondrocyte-derived osteoblast differentiation. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

M. fortuitum-induced CNS-pathology: Deciphering the role of canonical Wnt signaling, blood brain barrier components and cytokines

Molecular underpinning of mycobacteria-induced CNS-pathology is not well understood. In the present study, zebrafish were infected with Mycobacterium fortuitum and the prognosis of CNS-pathogenesis studied. We observed M. fortuitum triggers extensive brain-pathology. Evans blue extravasation demonstrated compromised blood-brain barrier (BBB) integrity. Further, decreased expression in tight-junction (TJ) and adherens junction complex (AJC) genes were noted in infected brain. Wnt-signaling has emerged as a major player in host-mycobacterial immunity but its involvement/role in brain-infection is not well studied. Sustained expression of wnt2, wnt3a, fzd5, lrp5/6 and β-catenin, with concordant decline in degradation complex components axin, gsk3β and β-catenin regulator capn2a were observed. The surge in ifng1 and tnfa expression preceding il10 and il4 suggested cytokine-interplay critical in M. fortuitum-induced brain-pathology. Therefore, we suggest adult zebrafish as a viable model for studying CNS-pathology and using the same, conclude that M. fortuitum infection is associated with repressed TJ-AJC gene expression and compromised BBB permeability. Our results implicate Wnt/β-catenin pathway in M. fortuitum-induced CNS-pathology wherein Th1-type signals facilitate bacterial clearance and Th2-type signals prevent the disease sequel.

The Small Molecule BC-2059 Inhibits Wingless/Integrated (Wnt)-Dependent Gene Transcription in Cancer through Disruption of the Transducin β-Like 1-β-Catenin Protein Complex

The central role of β-catenin in the Wnt pathway makes it an attractive therapeutic target for cancers driven by aberrant Wnt signaling. We recently developed a small-molecule inhibitor, BC-2059, that promotes apoptosis by disrupting the β-catenin/transducin β-like 1 (TBL1) complex through an unknown mechanism of action. In this study, we show that BC-2059 directly interacts with high affinity for TBL1 when in complex with β-catenin. We identified two amino acids in a hydrophobic pocket of TBL1 that are required for binding with β-catenin, and computational modeling predicted that BC-2059 interacts at the same hydrophobic pocket. Although this pocket in TBL1 is involved in binding with NCoR/SMRT complex members G Protein Pathway Suppressor 2 (GSP2) and SMRT and p65 NFκB subunit, BC-2059 failed to disrupt the interaction of TBL1 with either NCoR/SMRT or NFκB. Together, our results show that BC-2059 selectively targets TBL1/β-catenin protein complex, suggesting BC-2059 as a therapeutic for tumors with deregulated Wnt signaling pathway. SIGNIFICANCE STATEMENT: This study reports the mechanism of action of a novel Wnt pathway inhibitor, characterizing the selective disruption of the transducin β-like 1/β-catenin protein complex. As Wnt signaling is dysregulated across cancer types, this study suggests BC-2059 has the potential to benefit patients with tumors reliant on this pathway.

Neuronal Excitability in Epileptogenic Zones Regulated by the Wnt/ Β-Catenin Pathway

Epilepsy is a neurological disorder that involves abnormal and recurrent neuronal discharges, producing epileptic seizures. Recently, it has been proposed that the Wnt signaling pathway is essential for the central nervous system development and function because it modulates important processes such as hippocampal neurogenesis, synaptic clefting, and mitochondrial regulation. Wnt/β- catenin signaling regulates changes induced by epileptic seizures, including neuronal death. Several genetic studies associate Wnt/β-catenin signaling with neuronal excitability and epileptic activity. Mutations and chromosomal defects underlying syndromic or inherited epileptic seizures have been identified. However, genetic factors underlying the susceptibility of an individual to develop epileptic seizures have not been fully studied yet. In this review, we describe the genes involved in neuronal excitability in epileptogenic zones dependent on the Wnt/β-catenin pathway.

Wnt Signaling: From Mesenchymal Cell Fate to Lipogenesis and Other Mature Adipocyte Functions

Wnt signaling is an ancient and evolutionarily conserved pathway with fundamental roles in the development of adipose tissues. Roles of this pathway in mesenchymal stem cell fate determination and differentiation have been extensively studied. Indeed, canonical Wnt signaling is a significant endogenous inhibitor of adipogenesis and promoter of other cell fates, including osteogenesis, chondrogenesis, and myogenesis. However, emerging genetic evidence in both humans and mice suggests central roles for Wnt signaling in body fat distribution, obesity, and metabolic dysfunction. Herein, we highlight recent studies that have begun to unravel the contributions of various Wnt pathway members to critical adipocyte functions, including carbohydrate and lipid metabolism. We further explore compelling evidence of complex and coordinated interactions between adipocytes and other cell types within adipose tissues, including stromal, immune, and endothelial cells. Given the evolutionary conservation and ubiquitous cellular distribution of this pathway, uncovering the contributions of Wnt signaling to cell metabolism has exciting implications for therapeutic intervention in widespread pathologic states, including obesity, diabetes, and cancers.

Parallel and Sequential Pathways of Molecular Recognition of a Tandem-Repeat Protein and Its Intrinsically Disordered Binding Partner

The Wnt signalling pathway plays an important role in cell proliferation, differentiation, and fate decisions in embryonic development and the maintenance of adult tissues. The twelve armadillo (ARM) repeat-containing protein β-catenin acts as the signal transducer in this pathway. Here, we investigated the interaction between β-catenin and the intrinsically disordered transcription factor TCF7L2, comprising a very long nanomolar-affinity interface of approximately 4800 Å2 that spans ten of the twelve ARM repeats of β-catenin. First, a fluorescence reporter system for the interaction was engineered and used to determine the kinetic rate constants for the association and dissociation. The association kinetics of TCF7L2 and β-catenin were monophasic and rapid (7.3 ± 0.1 × 107 M-1·s-1), whereas dissociation was biphasic and slow (5.7 ± 0.4 × 10-4 s-1, 15.2 ± 2.8 × 10-4 s-1). This reporter system was then combined with site-directed mutagenesis to investigate the striking variability in the conformation adopted by TCF7L2 in the three different crystal structures of the TCF7L2-β-catenin complex. We found that the mutation had very little effect on the association kinetics, indicating that most interactions form after the rate-limiting barrier for association. Mutations of the N- and C-terminal subdomains of TCF7L2 that adopt relatively fixed conformations in the crystal structures had large effects on the dissociation kinetics, whereas the mutation of the labile sub-domain connecting them had negligible effect. These results point to a two-site avidity mechanism of binding with the linker region forming a "fuzzy" complex involving transient contacts that are not site-specific. Strikingly, the two mutations in the N-terminal subdomain that had the largest effects on the dissociation kinetics showed two additional phases, indicating partial flux through an alternative dissociation pathway that is inaccessible to the wild type. The results presented here provide insights into the kinetics of the molecular recognition of a long intrinsically disordered region with an elongated repeat-protein surface, a process found to involve parallel routes with sequential steps in each.

Effects of different concentrations of Chir98014 as an activator of Wnt/beta-catenin signaling pathway on oocyte in-vitro maturation and subsequent embryonic development in Sanjabi ewes

The present study was conducted to investigate the effects of the activator factor of the WNT pathway, chir98014, leading to the in vitro sheep oocyte maturation medium, on the cumulus cell development, different nuclear maturation stages and the following process of embryonic development. Experiments included (a) addition of different concentrations (0, 0.1, 0.5, 1 µm) of chir98014 to the maturation medium and evaluation of the cumulus cell expansion, (b) addition of different concentrations of chir98014 to the maturation medium and investigation of different nuclear maturation stages, (c) addition of different concentrations of chir98014 to the maturation medium and examination of the subsequent embryonic maturation process and (d) addition of different concentrations of chir98014 to the embryonic development culture medium (the first 48 hr) and investigation of the subsequent embryonic development process. The extracted data were analysed using the SPSS software, considering the significance level of p < .05 and making the mean comparisons. The results showed that the addition of the 0.1 µM concentration of chir98014 to the maturation medium had no significant effects on the oocyte maturation and embryo development post-fertilization but it enhanced the Cumulus-oocyte complexes (COCs) expansion. In the fourth experiment, the low concentration of chir98014 in the embryo culture media improved the embryo development process, whereas the high one had a detrimental effect on it, as compared to the control group. Thus, the presence of the lower concentrations of this compound in the embryonic culture medium had favourable effects on the development of embryos.

Loss of Apc Cooperates with Activated Oncogenes to Induce Liver Tumor Formation in Mice

Hepatocellular carcinoma (HCC) and hepatoblastoma are the major types of primary liver cancer in adulthood and childhood, respectively. Wnt/β-catenin signaling deregulation is one of the most frequent genetic events in hepatocarcinogenesis. APC regulator of WNT signaling pathway (APC) encodes an inhibitor of the Wnt cascade and acts as a tumor suppressor. Germline defects of the APC gene lead to familial adenomatous polyposis, and its somatic mutations occur in multiple tumor types. However, the contribution of APC in hepatocarcinogenesis remains unclear. Therefore, APC mutations and expression patterns were examined in human HCC and hepatoblastoma samples. Whether loss of Apc alone or in cooperation with other oncogenes triggers liver tumor development in vivo was also investigated. sgApc alone could not drive liver tumor formation, but synergized with activated oncogenes (YapS127A, TazS89A, and c-Met) to induce hepatocarcinogenesis. Mechanistically, Apc deletion induced the activation of β-catenin and its downstream targets in mouse liver tumors. Furthermore, Ctnnb1 ablation or TCF4-mediated transcription blockade completely prevented liver tumor formation, indicating the requirement of a functional β-catenin pathway for loss of Apc-driven hepatocarcinogenesis. This study shows that a subset of HCC patients with loss-of-function APC mutations might benefit from therapeutic strategies targeting the Wnt/β-catenin pathway.

BMP4 activates the Wnt-Lin28A-Blimp1-Wnt pathway to promote primordial germ cell formation via altering H3K4me2

The unique developmental characteristics of chicken primordial germ cells (PGCs) enable them to be used in recovery of endangered bird species, gene editing and the generation of transgenic birds, but the limited number of PGCs greatly limits their application. Studies have shown that the formation of mammalian PGCs is induced by BMP4 signal, but the mechanism underlying chicken PGC formation has not been determined. Here, we confirmed that Wnt signaling activated via BMP4 activates transcription of Lin28A by inducing β-catenin to compete with LSD1 for binding to TCF7L2, causing LSD1 to dissociate from the Lin28A promoter and enhancing H3K4me2 methylation in this region. Lin28A promotes PGC formation by inhibiting gga-let7a-3p maturation to initiate Blimp1 expression. Interestingly, expression of Blimp1 helped sustain Wnt5A expression by preventing LSD1 binding to the Wnt5A promoter. We thus elucidated a positive feedback pathway involving Wnt-Lin28A-Blimp1-Wnt that ensures PGC formation. In summary, our data provide new insight into the development of PGCs in chickens.

Vitamin K2 promotes the osteogenic differentiation of periodontal ligament stem cells via the Wnt/β-catenin signaling pathway

OBJECTIVE

Vitamin K2 (MK-4, menaquinone 4) plays an important role in osteoprotection. The present study aimed to examine the effect of MK-4 on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in vitro and probed the potential signaling pathway.

DESIGN

PDLSCs were isolated from extracted premolars by tissue block culture method and were identified by flow cytometry. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to determine the effect of MK-4 on the proliferation of PDLSCs. Alkaline phosphatase (ALP) activity was analyzed quantitatively, and extracellular matrix mineralization was examined by Alizarin Red S staining. The mRNA and protein expression levels of ALP, Runx Family Transcription Factor 2 (Runx2), osteocalcin (OCN), and Sp7 Transcription Factor (SP7; Osterix) were measured by qRT-PCR and Western blot. In addition, after adding the inhibitor XAV-939, Western blot was used to assess the correlation with the Wnt/β-catenin signaling pathway. The above results were obtained by observing at least three fields randomly, and each experiment was repeated at least three times.

RESULTS

This study found that 10^-5 M MK-4 significantly promoted the osteogenic differentiation of PDLSCs. Gene and protein expression levels of ALP, Runx2, OCN, and Osterix were all upregulated compared with control. Remarkably, after blocking the Wnt/β-catenin signaling pathway with XAV-939, the effect of MK-4 was apparently reversed.

CONCLUSION

These results demonstrate that MK-4 can promote the osteogenic differentiation of PDLSCs, which is likely related to the activation of the Wnt/β-catenin signaling pathway.

Bcl9 Depletion Modulates Endothelial Cell in Tumor Immune Microenvironment in Colorectal Cancer Tumor

Tumor endothelial cells are an important part of the tumor microenvironment, and angiogenesis inhibitory therapy has shown potential in tumor treatment. However, which subtypes of tumor endothelial cells are distributed in tumors, what are the differences between tumor endothelial cells and normal endothelial cells, and what is the mechanism of angiogenesis inhibitory therapy at the histological level, are all need to be resolved urgently. Using single-cell mRNA sequencing, we analyzed 12 CT26 colon cancer samples from mice, and found that knockdown of the downstream factor BCL9 in the Wnt signaling pathway or inhibitor-mediated functional inhibition can modulate tumor endothelial cells at a relatively primitive stage, inhibiting their differentiation into further extracellular matrix construction and angiogenesis functions. Furthermore, we propose a BCL9-endo-Score based on the differential expression of cells related to different states of BCL9 functions. Using published data sets with normal endothelial cells, we found that this score can characterize endothelial cells at different stages of differentiation. Finally, in the The Cancer Genome Atlas (TCGA) pan-cancer database, we found that BCL9-endo-Score can well predict the prognosis of diseases including colon cancer, kidney cancer and breast cancer, and identified the markers of these tumor subtypes, provide a basis for the prognosis prediction of patients with such types of tumor. Our data also contributed knowledge for tumor precision treatment with angiogenesis inhibitory therapy by targeting the Wnt signaling pathway.

Expression and Function of WNT6: From Development to Disease

WNT family member 6 (WNT6) is a member of the highly conserved WNT protein family. It plays an essential role in the normal development process, not only in embryonic morphogenesis, but also in post-natal homeostasis. WNT6 functions in mice and humans. This review summarizes the current findings on the biological functions of WNT6, describing its involvement in regulating embryogenesis, decidualization, and organ development. Aberrant WNT6 signaling is related to various pathologies, such as promoting cancer development, lung tuberculosis, and kidney fibrosis and improving the symptoms of Rett syndrome (RTT). Thus, due to its various functions, WNT6 has great potential for in-depth research. This work not only describes the signaling mechanism and function of WNT6 under physiological and pathological conditions, but also provides a theoretical basis for targeted therapy.

CREPT is required for murine stem cell maintenance during intestinal regeneration

Intestinal stem cells (ISCs) residing in the crypts are critical for the continual self-renewal and rapid recovery of the intestinal epithelium. The regulatory mechanism of ISCs is not fully understood. Here we report that CREPT, a recently identified tumor-promoting protein, is required for the maintenance of murine ISCs. CREPT is preferably expressed in the crypts but not in the villi. Deletion of CREPT in the intestinal epithelium of mice (Vil-CREPTKO) results in lower body weight and slow migration of epithelial cells in the intestine. Vil-CREPTKO intestine fails to regenerate after X-ray irradiation and dextran sulfate sodium (DSS) treatment. Accordingly, the deletion of CREPT decreases the expression of genes related to the proliferation and differentiation of ISCs and reduces Lgr5+ cell numbers at homeostasis. We identify that CREPT deficiency downregulates Wnt signaling by impairing β-catenin accumulation in the nucleus of the crypt cells during regeneration. Our study provides a previously undefined regulator of ISCs.

CREPT is required for murine stem cell maintenance during intestinal regeneration

Intestinal stem cells (ISCs) residing in the crypts are critical for the continual self-renewal and rapid recovery of the intestinal epithelium. The regulatory mechanism of ISCs is not fully understood. Here we report that CREPT, a recently identified tumor-promoting protein, is required for the maintenance of murine ISCs. CREPT is preferably expressed in the crypts but not in the villi. Deletion of CREPT in the intestinal epithelium of mice (Vil-CREPTKO) results in lower body weight and slow migration of epithelial cells in the intestine. Vil-CREPTKO intestine fails to regenerate after X-ray irradiation and dextran sulfate sodium (DSS) treatment. Accordingly, the deletion of CREPT decreases the expression of genes related to the proliferation and differentiation of ISCs and reduces Lgr5+ cell numbers at homeostasis. We identify that CREPT deficiency downregulates Wnt signaling by impairing β-catenin accumulation in the nucleus of the crypt cells during regeneration. Our study provides a previously undefined regulator of ISCs.

Mining Natural Compounds to Target WNT Signaling: Land and Sea Tales

WNT signaling plays paramount roles in organism development, physiology, and disease, representing a highly attractive target for drug development. However, no WNT-modulating drugs have been approved, with several candidates trudging through the early clinical trials. This delay instigates alternative approaches to discover WNT-modulating drugs. Natural products were the source of therapeutics for centuries, but the chemical diversity they offer, especially when looking at different taxonomic groups and habitats, is still to a large extent unexplored. These considerations urge researchers to screen natural compounds for the WNT-modulatory activities. Since several reviews on such endeavors exist, we here have attempted to present these efforts as "Land and sea tales" (citing the book title by Rudyard Kipling) superimposing them onto the traditional pipeline of drug discovery and early development. In doing so, we illustrate each step of the pipeline with case studies stemming from our own research. It will become obvious that several steps of the pipeline need to be modified when applied to natural products rather than to synthetic libraries. Yet the main message of this chapter is that natural compounds represent a powerful source for the WNT signaling modulators and can be developed towards drug candidates against WNT-dependent maladies.

Wnt signalling pathway in bladder cancer

Bladder cancer (BC) is one of the most common tumours of the urinary system and is also known as a highly malignant tumour. In addition to conventional diagnosis and treatment methods, recent research has focused on studying the molecular mechanisms related to BC, in the hope that new, less toxic and effective targeted anticancer drugs and new diagnostic markers can be discovered. It is known that the Wingless (Wnt) signalling pathway and its related genes, proteins and other substances are involved in multiple biological processes of various tumours. Clarifying the contribution of the Wnt signalling pathway in bladder tumours will help establish early diagnosis indicators, develop new therapeutic drugs and evaluate the prognosis for BC. This review aims to summarise previous studies related to BC and the Wnt signalling pathway, with a focus on exploring the participating substances and their mechanisms in the regulation of the Wnt signalling pathway to better determine how to promote new chemotherapeutic drugs, potential therapeutic targets and diagnostic biomarkers.

PAR1&2 driven placenta EVT invasion act via LRP5/6 as coreceptors

While the involvement of protease-activated receptors (PARs) in the physiological regulation of human placenta development, as in tumor biology, is recognized, the molecular pathway is unknown. We evaluated the impact of PAR₁ and PAR₂ function in cytotrophoblast (CTB) proliferation and invasion in a system of extravillous trophoblast (EVT) organ culture and in human cell-lines. Activation of PAR₁ - and PAR₂ -induced EVT invasion and proliferation, while the shRNA silencing of low-density lipoprotein receptor-related protein 5/6 (LRP5/6) inhibited these processes. PAR₁ and PAR₂ effectively induce β-catenin stabilization in a manner similar to that shown for the canonical β-catenin stabilization pathway yet independent of Wnts. Immunoprecipitation analyses and protein-protein docking demonstrated the co-association between either PAR₁ or PAR₂ with LRP5/6 forming an axis of PAR-LRP5/6-Axin. Noticeably, in PAR₁ -PAR₂ heterodimers a dominant role is assigned to PAR₂ over PAR₁ as shown by inhibition of PAR₁ -induced β-catenin levels, and Dvl nuclear localization. This inhibition takes place either by shRNA silenced hPar2 or in the presence of a TrPAR₂ devoid its cytoplasmic tail. Indeed, TrPAR₂ cannot form the PAR₁ -PAR₂ complex, obstructing thereby the flow of signals downstream. Elucidation of the mechanism of PAR-induced invasion contributes to therapeutic options highlighting key partners in the process.