ABSTRACT
A substantial number of hereditary colorectal cancer (CRC) and colonic polyposis cannot be explained by alteration in confirmed predisposition genes, such as mismatch repair (MMR) genes, APC and MUTYH. Recently, a certain number of potential predisposition genes have been suggested, involving each a small number of cases reported so far. Here, we describe the detection of rare variants in the NTLH1, AXIN2, RNF43, BUB1, and TP53 genes in nine unrelated patients who were suspected for inherited CRC and/or colonic polyposis. Seven of them were classified as pathogenic or likely pathogenic variants (PV/LPV). Clinical manifestations of carriers were largely consistent with reported cases with, nevertheless, distinct characteristics. PV/LPV in these uncommon gene can be responsible for up to 2.7% of inherited CRC or colonic polyposis syndromes. Our findings provide supporting evidence for the role of these genes in cancer predisposition, and contribute to the determination of related cancer spectrum and cancer risk for carriers, allowing for the establishment of appropriate screening strategy and genetic counseling in affected families.
Subject(s)
Adenomatous Polyposis Coli , Genetic Predisposition to Disease , Humans , Female , Male , Middle Aged , Adult , Adenomatous Polyposis Coli/genetics , Ubiquitin-Protein Ligases/genetics , Axin Protein/genetics , Colorectal Neoplasms/genetics , Tumor Suppressor Protein p53/genetics , Aged , Protein Serine-Threonine Kinases/genetics , DNA-Binding Proteins/genetics , Deoxyribonuclease (Pyrimidine Dimer)ABSTRACT
Peroxisomes are membrane-bound organelles harboring metabolic enzymes. In humans, peroxisomes are required for normal development, yet the genes regulating peroxisome function remain unclear. We performed a genome-wide CRISPRi screen to identify novel factors involved in peroxisomal homeostasis. We found that inhibition of RNF146, an E3 ligase activated by poly(ADP-ribose), reduced the import of proteins into peroxisomes. RNF146-mediated loss of peroxisome import depended on the stabilization and activity of the poly(ADP-ribose) polymerases TNKS and TNKS2, which bind the peroxisomal membrane protein PEX14. We propose that RNF146 and TNKS/2 regulate peroxisome import efficiency by PARsylation of proteins at the peroxisome membrane. Interestingly, we found that the loss of peroxisomes increased TNKS/2 and RNF146-dependent degradation of non-peroxisomal substrates, including the ß-catenin destruction complex component AXIN1, which was sufficient to alter the amplitude of ß-catenin transcription. Together, these observations not only suggest previously undescribed roles for RNF146 in peroxisomal regulation but also a novel role in bridging peroxisome function with Wnt/ß-catenin signaling during development.
Subject(s)
Axin Protein , Peroxisomes , Ubiquitin-Protein Ligases , Wnt Signaling Pathway , Peroxisomes/metabolism , Peroxisomes/genetics , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Humans , Axin Protein/metabolism , Axin Protein/genetics , Membrane Proteins/metabolism , Membrane Proteins/genetics , beta Catenin/metabolism , beta Catenin/genetics , HEK293 Cells , Protein Transport , CRISPR-Cas SystemsABSTRACT
OBJECTIVE: To investigate the protective effect of the Chinese herbal formula of Jiedu Huayu decoction (, JHD) on oral mucosa of rats with oral submucosal fibrosis (OSF) and its potential mechanism of action. METHODS: Sprague-Dawley male OSF model rats were constructed by injection of betaine and topical rubbing and were randomly grouped and administered by gavage for 4 weeks. Mouth opening and buccal mucosa scores interleukin levels and the expression of Axin and ß-catenin proteins or genes were measured before and after drug administration. RESULTS: After treatment with JHD the buccal mucosal lesions of rats were significantly reduced Axin protein and mRNA expression were significantly increased ß-catenin protein and mRNA expression were significantly decreased interleukin-1ß and interleukin-6 levels were decreased and interleukin-10 levels were increased. CONCLUSION: The mechanism of action of JHD can effectively alleviate the pathological damage of buccal mucosa in OSF rats which may be related to the promotion of Axin expression and inhibition of ß-catenin expression.
Subject(s)
Axin Protein , Drugs, Chinese Herbal , Mouth Mucosa , Rats, Sprague-Dawley , beta Catenin , Animals , Drugs, Chinese Herbal/administration & dosage , Male , beta Catenin/metabolism , beta Catenin/genetics , Rats , Axin Protein/genetics , Axin Protein/metabolism , Mouth Mucosa/metabolism , Mouth Mucosa/drug effects , Humans , Oral Submucous Fibrosis/drug therapy , Oral Submucous Fibrosis/metabolism , Oral Submucous Fibrosis/genetics , Disease Models, AnimalABSTRACT
The hypoxic microenvironment in esophageal carcinoma is an important factor promoting the rapid progression of malignant tumor. This study was to investigate the lactylation of Axin1 on glycolysis in esophageal carcinoma cells under hypoxia exposure. Hypoxia treatment increases pan lysine lactylation (pan-kla) levels of both TE1 and EC109 cells. Meanwhile, ECAR, glucose consumption and lactate production were also upregulated in both TE1 and EC109 cells. The expression of embryonic stem cell transcription factors NANOG and SOX2 were enhanced in the hypoxia-treated cells. Axin1 overexpression partly reverses the induction effects of hypoxia treatment in TE1 and EC109 cells. Moreover, lactylation of Axin1 protein at K147 induced by hypoxia treatment promotes ubiquitination modification of Axin1 protein to promote glycolysis and cell stemness of TE1 and EC109 cells. Mutant Axin1 can inhibit ECAR, glucose uptake, lactate secretion, and cell stemness in TE1 and EC109 cells under normal or hypoxia conditions. Meanwhile, mutant Axin1 further enhanced the effects of 2-DG on inhibiting glycolysis and cell stemness. Overexpression of Axin1 also inhibited tumor growth in vivo, and was related to suppressing glycolysis. In conclusion, hypoxia treatment promoted the glycolysis and cell stemness of esophageal carcinoma cells, and increased the lactylation of Axin1 protein. Overexpression of Axin1 functioned as a glycolysis inhibitor, and suppressed the effects of hypoxia exposure in vitro and inhibited tumor growth in vivo. Mechanically, hypoxia induces the lactylation of Axin1 protein and promotes the ubiquitination of Axin1 to degrade the protein, thereby exercising its anti-glycolytic function.
Subject(s)
Axin Protein , Esophageal Neoplasms , Glycolysis , Mice, Nude , Humans , Axin Protein/metabolism , Axin Protein/genetics , Esophageal Neoplasms/metabolism , Esophageal Neoplasms/pathology , Glycolysis/physiology , Animals , Cell Line, Tumor , Mice , Mice, Inbred BALB C , Cell Hypoxia/physiologyABSTRACT
OBJECTIVE: To explore the causal relationship between inflammatory protein markers and the risk of colorectal cancer using a Mendelian randomization (MR) approach. METHODS: We obtained data pertaining to colorectal cancer from Genome-Wide Association Study (GWAS) datasets and used 91 inflammatory protein markers as the exposure variables. A two-sample MR analysis model was used to assess the causal link between the inflammatory markers and colorectal cancer risk. The robustness of the results was evaluated through heterogeneity, pleiotropy, and sensitivity analyses using 5 MR models: Inverse Variance Weighted (IVW), Weighted Median, MR Egger, Simple Mode, and Weighted Mode. We examined the mRNA expressions of PD-L1, AXIN1, and ß-NGF using RT-qPCR in 86 untreated patients with colorectal adenocarcinoma admitted in Nanfang Hospital between December, 2021 and December 2023, and analyzed their correlation with the clinical characteristics of the patients. RESULTS: Using the IVW model, MR analysis revealed significant causal associations between a reduced risk of colorectal cancer and lowered expressions of AXIN1 (OR=0.866, 95% CI: 0.754-0.994, P=0.040), ß-NGF (OR=0.914, 95% CI: 0.843-0.990, P=0.028; OR=0.884, 95% CI: 0.784-0.998, P=0.047 using Weighted Median model), and PD-L1 (OR=0.903, 95% CI: 0.824- 0.989, P=0.028). No significant heterogeneity or pleiotropy was observed, indicating good stability of the results. Sensitivity analysis confirmed the reliability of the findings. The clinical study demonstrated a significant correlation between PD-L1 expression and TNM staging, particularly in stage â £ patients (P=0.007). AXIN1 and ß -NGF expression levels were significantly correlated with the degree of tumor differentiation, and their expressions were higher in poorly differentiated samples (P<0.001). CONCLUSION: Lowered expressions of inflammatory protein markers AXIN1, ß-NGF, and PD-L1 are causally correlated with a reduced risk of colorectal cancer and their expression levels are associated with TNM staging and tumor differentiation. These markers may thus serve as potential targets for colorectal cancer treatment and prevention.
Subject(s)
Axin Protein , Colorectal Neoplasms , Genome-Wide Association Study , Mendelian Randomization Analysis , Humans , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Prognosis , Axin Protein/genetics , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , B7-H1 Antigen/genetics , B7-H1 Antigen/metabolism , Male , Female , Inflammation , Middle Aged , Risk FactorsABSTRACT
Autism spectrum disorder (ASD) is a group of neurodevelopment disorders characterized by deficits in social interaction and communication, and repetitive or stereotyped behavior. Autistic children are more likely to have vision problems, and ASD is unusually common among blind people. However, the mechanisms behind the vision disorders in autism are unclear. Stabilizing WNT-targeted scaffold protein Axin2 by XAV939 during embryonic development causes overproduction of cortical neurons and leads to autistic-like behaviors in mice. In this study, we investigated the relationship between vision abnormality and autism using an XAV939-induced mouse model of autism. We found that the mice receiving XAV939 had decreased amplitude of bright light-adaptive ERG. The amplitudes and latency of flash visual evoked potential recorded from XAV939-treated mice were lower and longer, respectively than in the control mice, suggesting that XAV939 inhibits visual signal processing and conductance. Anatomically, the diameters of RGC axons were reduced when Axin2 was stabilized during the development, and the optic fibers had defective myelin sheaths and reduced oligodendrocytes. The results suggest that the WNT signaling pathway is crucial for optic nerve development. This study provides experimental evidence that conditions interfering with brain development may also lead to visual problems, which in turn might exaggerate the autistic features in humans.
Subject(s)
Axin Protein , Disease Models, Animal , Evoked Potentials, Visual , Optic Nerve , Animals , Axin Protein/metabolism , Mice , Evoked Potentials, Visual/physiology , Optic Nerve/metabolism , Optic Nerve/pathology , Electroretinography , Mice, Inbred C57BL , Axons/pathology , Retinal Ganglion Cells/pathology , Retinal Ganglion Cells/metabolism , Male , Wnt Signaling Pathway/physiology , Autism Spectrum Disorder/physiopathology , Autism Spectrum Disorder/metabolism , Autistic Disorder/physiopathology , Autistic Disorder/metabolismABSTRACT
The association of BRCA1 and BRCA2 mutations with increased risk for developing epithelial ovarian cancer is well established. However, the observed clinical differences, particularly the improved therapy response and patient survival in BRCA2-mutant patients, are unexplained. Our objective is to identify molecular pathways that are differentially regulated upon the loss of BRCA1 and BRCA2 functions in ovarian cancer. Transcriptomic and pathway analyses comparing BRCA1-mutant, BRCA2-mutant, and homologous recombination wild-type ovarian tumors showed differential regulation of the Wnt/ß-catenin pathway. Using Wnt3A-treated BRCA1/2 wild-type, BRCA1-null, and BRCA2-null mouse ovarian cancer cells, we observed preferential activation of canonical Wnt/ß-catenin signaling in BRCA1/2 wild-type ovarian cancer cells, whereas noncanonical Wnt/ß-catenin signaling was preferentially activated in the BRCA1-null ovarian cancer cells. Interestingly, BRCA2-null mouse ovarian cancer cells demonstrated a unique response to Wnt3A with the preferential upregulation of the Wnt signaling inhibitor Axin2. In addition, decreased phosphorylation and enhanced stability of ß-catenin were observed in BRCA2-null mouse ovarian cancer cells, which correlated with increased inhibitory phosphorylation on GSK3ß. These findings open venues for the translation of these molecular observations into modalities that can impact patient survival. SIGNIFICANCE: We show that BRCA1 and BRCA2 mutation statuses differentially impact the regulation of the Wnt/ß-catenin signaling pathway, a major effector of cancer initiation and progression. Our findings provide a better understanding of molecular mechanisms that promote the known differential clinical profile in these patient populations.
Subject(s)
BRCA1 Protein , BRCA2 Protein , Carcinoma, Ovarian Epithelial , Ovarian Neoplasms , Wnt Signaling Pathway , Female , Animals , Wnt Signaling Pathway/genetics , Wnt Signaling Pathway/drug effects , Carcinoma, Ovarian Epithelial/genetics , Carcinoma, Ovarian Epithelial/metabolism , Carcinoma, Ovarian Epithelial/pathology , Mice , Humans , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , BRCA1 Protein/genetics , BRCA1 Protein/metabolism , BRCA2 Protein/genetics , BRCA2 Protein/metabolism , Cell Line, Tumor , beta Catenin/metabolism , beta Catenin/genetics , Axin Protein/genetics , Axin Protein/metabolism , Wnt3A Protein/metabolism , Wnt3A Protein/genetics , Gene Expression Regulation, Neoplastic , MutationABSTRACT
BACKGROUND: Hepatocellular carcinoma (HCC) is a highly aggressive liver cancer with significant morbidity and mortality rates. AXIN1 is one of the top-mutated genes in HCC, but the mechanism by which AXIN1 mutations contribute to HCC development remains unclear. METHODS: In this study, we utilized CRISPR/Cas9 genome editing to repair AXIN1-truncated mutations in five HCC cell lines. RESULTS: For each cell line we successfully obtained 2-4 correctly repaired clones, which all show reduced ß-catenin signaling accompanied with reduced cell viability and colony formation. Although exposure of repaired clones to Wnt3A-conditioned medium restored ß-catenin signaling, it did not or only partially recover their growth characteristics, indicating the involvement of additional mechanisms. Through RNA-sequencing analysis, we explored the gene expression patterns associated with repaired AXIN1 clones. Except for some highly-responsive ß-catenin target genes, no consistent alteration in gene/pathway expression was observed. This observation also applies to the Notch and YAP/TAZ-Hippo signaling pathways, which have been associated with AXIN1-mutant HCCs previously. The AXIN1-repaired clones also cannot confirm a recent observation that AXIN1 is directly linked to YAP/TAZ protein stability and signaling. CONCLUSIONS: Our study provides insights into the effects of repairing AXIN1 mutations on ß-catenin signaling, cell viability, and colony formation in HCC cell lines. However, further investigations are necessary to understand the complex mechanisms underlying HCC development associated with AXIN1 mutations.
Subject(s)
Axin Protein , CRISPR-Cas Systems , Carcinoma, Hepatocellular , Liver Neoplasms , Mutation , beta Catenin , Axin Protein/genetics , Axin Protein/metabolism , Humans , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Liver Neoplasms/metabolism , Cell Line, Tumor , beta Catenin/metabolism , beta Catenin/genetics , Gene Expression Regulation, Neoplastic , Gene Editing , Signal Transduction/geneticsABSTRACT
Wnt/ß-catenin signaling plays important role in cancers. Compound 759 is one of the compounds previously screened to identify inhibitors of the Wnt/ß-catenin pathway in A549 cells [Lee et al. in Bioorg Med Chem Lett 20:5900-5904, 2010]. However, the mechanism by which Compound 759 induces the inhibition of the Wnt/ß-catenin pathway remains unknown. In our study, we employed various assays to comprehensively evaluate the effects of Compound 759 on lung cancer cells. Our results demonstrated that Compound 759 significantly suppressed cell proliferation and Wnt3a-induced Topflash activity and arrested the cell cycle at the G1 stage. Changes in Wnt/ß-catenin signaling-related protein expression, gene activity, and protein stability including Axin, and p21, were achieved through western blot and qRT-PCR analysis. Compound 759 treatment upregulated the mRNA level of p21 and increased Axin protein levels without altering the mRNA expression in A549 cells. Co-treatment of Wnt3a and varying doses of Compound 759 dose-dependently increased the amounts of Axin1 in the cytosol and inhibited ß-catenin translocation into the nucleus. Moreover, Compound 759 reduced tumor size and weight in the A549 cell-induced tumor growth in the in vivo tumor xenograft mouse model. Our findings indicate that Compound 759 exhibits potential anti-cancer activity by inhibiting the Wnt/ß-catenin signaling pathway through the increase of Axin1 protein stability.
Subject(s)
Axin Protein , Cell Proliferation , Lung Neoplasms , Wnt Signaling Pathway , Animals , Humans , Mice , A549 Cells , Antineoplastic Agents/pharmacology , Axin Protein/drug effects , Axin Protein/metabolism , beta Catenin/metabolism , beta Catenin/antagonists & inhibitors , Cell Line, Tumor , Cell Proliferation/drug effects , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice, Inbred BALB C , Mice, Nude , Protein Stability/drug effects , Wnt Signaling Pathway/drug effects , Wnt3A Protein/drug effects , Wnt3A Protein/metabolism , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Ubiquitin-conjugating enzyme E2 N (UBE2N) is recognized in the progression of some cancers; however, little research has been conducted to describe its role in prostate cancer. The purpose of this paper is to explore the function and mechanism of UBE2N in prostate cancer cells. METHODS: UBE2N expression was detected in Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) data, prostate cancer tissue microarrays, and prostate cancer cell lines, respectively. UBE2N knockdown or overexpression was used to analyze its role in cell viability and glycolysis of prostate cancer cells and tumor growth. XAV939 or Axin1 overexpression was co-treated with UBE2N overexpression to detect the involvement of the Wnt/ß-catenin signaling and Axin1 in the UBE2N function. UBE2N interacting with Axin1 was analyzed by co-immunoprecipitation assay. RESULTS: UBE2N was upregulated in prostate cancer and the UBE2N-high expression correlated with the poor prognosis of prostate cancer. UBE2N knockdown inhibited cell viability and glycolysis in prostate cancer cells and restricted tumor formation in tumor-bearing mice. Wnt/ß-catenin inhibition and Axin1 overexpression reversed the promoting viability and glycolysis function of UBE2N. UBE2N promoted Axin1 ubiquitination and decreased Axin1 protein level.
Subject(s)
Axin Protein , Cell Survival , Glycolysis , Prostatic Neoplasms , Ubiquitin-Conjugating Enzymes , Ubiquitination , Animals , Humans , Male , Mice , Axin Protein/metabolism , Axin Protein/genetics , Cell Line, Tumor , Mice, Nude , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/genetics , Ubiquitin-Conjugating Enzymes/metabolism , Ubiquitin-Conjugating Enzymes/genetics , Wnt Signaling PathwayABSTRACT
Wnt signaling is a crucial developmental pathway involved in early development as well as stem-cell maintenance in adults and its misregulation leads to numerous diseases. Thus, understanding the regulation of this pathway becomes vitally important. Axin2 and Nkd1 are widely utilized negative feedback regulators in Wnt signaling where Axin2 functions to destabilize cytoplasmic ß-catenin, and Nkd1 functions to inhibit the nuclear localization of ß-catenin. Here, we set out to further understand how Axin2 and Nkd1 regulate Wnt signaling by creating axin2gh1/gh1, nkd1gh2/gh2 single mutants and axin2gh1/gh1;nkd1gh2/gh2 double mutant zebrafish using sgRNA/Cas9. All three Wnt regulator mutants were viable and had impaired heart looping, neuromast migration defects, and behavior abnormalities in common, but there were no signs of synergy in the axin2gh1/gh1;nkd1gh2/gh2 double mutants. Further, Wnt target gene expression by qRT-PCR and RNA-seq, and protein expression by mass spectrometry demonstrated that the double axin2gh1/gh1;nkd1gh2/gh2 mutant resembled the nkd1gh2/gh2 phenotype demonstrating that Nkd1 functions downstream of Axin2. In support of this, the data further demonstrates that Axin2 uniquely alters the properties of ß-catenin-dependent transcription having novel readouts of Wnt activity compared with nkd1gh2/gh2 or the axin2gh1/gh1;nkd1gh2/gh2 double mutant. We also investigated the sensitivity of the Wnt regulator mutants to exacerbated Wnt signaling, where the single mutants displayed characteristic heightened Wnt sensitivity, resulting in an eyeless phenotype. Surprisingly, this phenotype was rescued in the double mutant, where we speculate that cross-talk between Wnt/ß-catenin and Wnt/Planar Cell Polarity pathways could lead to altered Wnt signaling in some scenarios. Collectively, the data emphasizes both the commonality and the complexity in the feedback regulation of Wnt signaling.
Subject(s)
Axin Protein , Wnt Signaling Pathway , Zebrafish Proteins , Zebrafish , beta Catenin , Animals , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Axin Protein/metabolism , Axin Protein/genetics , beta Catenin/metabolism , Carrier Proteins , Mutation/genetics , Zebrafish Proteins/metabolism , Zebrafish Proteins/geneticsABSTRACT
AXIN1 is a major component of the ß-catenin destruction complex and is frequently mutated in various cancer types, particularly liver cancers. Truncating AXIN1 mutations are recognized to encode a defective protein that leads to ß-catenin stabilization, but the functional consequences of missense mutations are not well characterized. Here, we first identified the GSK3ß, ß-catenin, and RGS/APC interaction domains of AXIN1 that are the most critical for proper ß-catenin regulation. Analysis of 80 tumor-associated variants in these domains identified 18 that significantly affected ß-catenin signaling. Coimmunoprecipitation experiments revealed that most of them lost binding to the binding partner corresponding to the mutated domain. A comprehensive protein structure analysis predicted the consequences of these mutations, which largely overlapped with the observed effects on ß-catenin signaling in functional experiments. The structure analysis also predicted that loss-of-function mutations within the RGS/APC interaction domain either directly affected the interface for APC binding or were located within the hydrophobic core and destabilized the entire structure. In addition, truncated AXIN1 length inversely correlated with the ß-catenin regulatory function, with longer proteins retaining more functionality. These analyses suggest that all AXIN1-truncating mutations at least partially affect ß-catenin regulation, whereas this is only the case for a subset of missense mutations. Consistently, most colorectal and liver cancers carrying missense variants acquire mutations in other ß-catenin regulatory genes such as APC and CTNNB1. These results will aid the functional annotation of AXIN1 mutations identified in large-scale sequencing efforts or in individual patients. SIGNIFICANCE: Characterization of 80 tumor-associated missense variants of AXIN1 reveals a subset of 18 mutations that disrupt its ß-catenin regulatory function, whereas the majority are passenger mutations.
Subject(s)
Axin Protein , Mutation, Missense , beta Catenin , Axin Protein/genetics , Axin Protein/metabolism , Humans , beta Catenin/genetics , beta Catenin/metabolism , Signal Transduction/genetics , Glycogen Synthase Kinase 3 beta/genetics , Glycogen Synthase Kinase 3 beta/metabolism , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Neoplasms/genetics , Neoplasms/pathology , Neoplasms/metabolism , HEK293 Cells , Cell Line, Tumor , Protein BindingABSTRACT
AXIN1, has been initially identified as a prominent antagonist within the WNT/ß-catenin signaling pathway, and subsequently unveiled its integral involvement across a diverse spectrum of signaling cascades. These encompass the WNT/ß-catenin, Hippo, TGFß, AMPK, mTOR, MAPK, and antioxidant signaling pathways. The versatile engagement of AXIN1 underscores its pivotal role in the modulation of developmental biological signaling, maintenance of metabolic homeostasis, and coordination of cellular stress responses. The multifaceted functionalities of AXIN1 render it as a compelling candidate for targeted intervention in the realms of degenerative pathologies, systemic metabolic disorders, cancer therapeutics, and anti-aging strategies. This review provides an intricate exploration of the mechanisms governing mammalian AXIN1 gene expression and protein turnover since its initial discovery, while also elucidating its significance in the regulation of signaling pathways, tissue development, and carcinogenesis. Furthermore, we have introduced the innovative concept of the AXIN1-Associated Phosphokinase Complex (AAPC), where the scaffold protein AXIN1 assumes a pivotal role in orchestrating site-specific phosphorylation modifications through interactions with various phosphokinases and their respective substrates.
Subject(s)
Wnt Signaling Pathway , beta Catenin , Animals , Gene Ontology , Axin Protein/genetics , Axin Protein/metabolism , Wnt Signaling Pathway/genetics , Phosphorylation , Proteolysis , beta Catenin/metabolism , Mammals/metabolismABSTRACT
Osimertinib, a promising and approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is a standard strategy for EGFR-mutant non-small cell lung cancer (NSCLC) patients. However, developed resistance is unavoidable, which reduces its long-term effectiveness. In this study, RNA sequencing was performed to analyze differentially expressed genes (DEGs). The PrognoScan database and Gene Expression Profiling Interactive Analysis (GEPIA) were used to identify the key genes for clinical prognosis and gene correlation respectively. Protein expression was determined by western blot analysis. Cell viability assay and Ki67 staining were used to evaluate the effect of osimertinib on tumor cells. Finally, we screened out two hub genes, myelocytomatosis oncogene (Myc) and axis inhibition protein 1 (Axin1), upregulated in three osimertinib-resistant cell lines through RNA sequencing and bioinformatics analysis. Next, cell experiment confirmed that expression of C-MYC and AXIN1 were elevated in different EGFR mutant NSCLC cell lines with acquired resistance to osimertinib, compared with their corresponding parental cell lines. Furthermore, we demonstrated that AXIN1 upregulated the expression of C-MYC and mediated the acquired resistance of EGFR mutant NSCLC cells to osimertinib in vitro. In conclusion, AXIN1 affected the sensitivity of EGFR mutant NSCLC to osimertinib via regulating C-MYC expression in vitro. Targeting AXIN1/MYC signaling may be a potential new strategy for overcoming acquired resistance to osimertinib.
Subject(s)
Acrylamides , Aniline Compounds , Axin Protein , Carcinoma, Non-Small-Cell Lung , Drug Resistance, Neoplasm , ErbB Receptors , Gene Expression Regulation, Neoplastic , Indoles , Lung Neoplasms , Mutation , Proto-Oncogene Proteins c-myc , Pyrimidines , Humans , Acrylamides/pharmacology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Aniline Compounds/pharmacology , ErbB Receptors/genetics , ErbB Receptors/metabolism , Drug Resistance, Neoplasm/genetics , Axin Protein/genetics , Axin Protein/metabolism , Cell Line, Tumor , Lung Neoplasms/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Mutation/genetics , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-myc/genetics , Gene Expression Regulation, Neoplastic/drug effects , Signal Transduction/drug effects , Signal Transduction/geneticsABSTRACT
Colorectal cancer (CRC) is one of the most common neoplasms worldwide. Among the risk factors of CRC, inflammatory bowel disease (IBD) is one of the most important ones leading to the development of colitis-associated CRC (CAC). G-protein coupled receptors (GPCR) are transmembrane receptors that orchestrate a multitude of signaling cascades in response to external stimuli. Because of their functionality, they are promising targets in research on new strategies for CRC diagnostics and treatment. Recently, regulators of G-proteins (RGS) have been attracting attention in the field of oncology. Typically, they serve as negative regulators of GPCR responses to both physiological stimuli and medications. RGS activity can lead to both beneficial and harmful effects depending on the nature of the stimulus. However, the atypical RGS-AXIN uses its RGS domain to antagonize key signaling pathways in CRC development through the stabilization of the ß-catenin destruction complex. Since AXIN does not limit the efficiency of medications, it seems to be an even more promising pharmacological target in CRC treatment. In this review, we discuss the current state of knowledge on RGS significance in sporadic CRC and CAC with particular emphasis on the regulation of GPCR involved in IBD-related inflammation comprising opioid, cannabinoid and serotonin receptors.
Subject(s)
Colitis-Associated Neoplasms , Inflammatory Bowel Diseases , Humans , Axin Protein , GTP-Binding Proteins , Signal Transduction , Inflammatory Bowel Diseases/complicationsABSTRACT
R-spondins (RSPOs) are secreted signaling molecules that potentiate the Wnt/ß-catenin pathway by cooperating with Wnt ligands. RSPO1 is crucial in tissue development and tissue homeostasis. However, the molecular mechanism by which RSPOs activate Wnt/ß-catenin signaling remains elusive. In this study, we found that RSPOs could mediate the degradation of Axin through the ubiquitin-proteasome pathway. The results of Co-IP showed that the recombinant RSPO1 protein promoted the interaction between Axin1 and CK1ε. Either knockout of the CK1ε gene or treatment with the CK1δ/CK1ε inhibitor SR3029 caused an increase in Axin1 protein levels and attenuated RSPO1-induced degradation of the Axin1 protein. Moreover, we observed an increase in the number of associations of LRP6 with CK1ε and Axin1 following RSPO1 stimulation. Overexpression of LRP6 further potentiated Axin1 degradation mediated by RSPO1 or CK1ε. In addition, recombinant RSPO1 and Wnt3A proteins synergistically downregulated the protein expression of Axin1 and enhanced the transcriptional activity of the SuperTOPFlash reporter. Taken together, these results uncover the novel mechanism by which RSPOs activate Wnt/ß-catenin signaling through LRP6/CK1ε-mediated degradation of Axin.
Subject(s)
Axin Protein , Thrombospondins , Wnt Signaling Pathway , beta Catenin , Biological Transport , Wnt3A Protein , Humans , Thrombospondins/metabolismABSTRACT
BACKGROUND: A myriad of therapeutic modalities for alopecia areata are available; however, none is of high level of evidence, creating an immense need for the evaluation of other treatment modalities, of which topical sodium valproate is of potential role via proposed decrease in beta-catenin breakdown, despite its well-known side effect of hair fall as an oral therapy. OBJECTIVE: Evaluating the efficacy and the safety of sodium valproate (SV)-loaded nanospanlastics, in comparison to topical corticosteroids, this is the currently available gold standard topical treatment for patchy AA. METHODOLOGY: A total of 66 patients with patchy AA were randomly assigned to receive either topical mometasone furoate lotion or topical SV applied twice daily to all patches except a control patch, which was left untreated. Clinical, trichoscopic and biochemical assessments of beta-catenin tissue levels and Axin-2 gene expression were carried out at baseline and after 3 months. RESULTS: Both therapeutic modalities were comparable. Potential efficacy was highlighted by significant improvement in the representative patch, the largest treated patch, to the control patch, the smallest untreated patch in both steroid and valproate groups (p = 0.027, 0.003 respectively). Both beta-catenin levels and Axin-2 gene expression were reduced after treatment, pointing to the inhibitory effect of dominating uncontrolled inflammatory milieu. Baseline beta-catenin was found to significantly negatively correlate with improvement in the representative patch in patients with baseline level above 0.42 ng/ml (p = - 0.042). CONCLUSION: Both topical SV and steroids are of comparable modest efficacy. Thus, further evaluation of SV is due in combination with intralesional steroids and other anti-inflammatory treatment modalities, together with developing individualized approaches based on baseline beta-catenin level. GOV IDENTIFIER: NCT05017454, https://clinicaltrials.gov/ct2/show/NCT05017454 .
Subject(s)
Alopecia Areata , Humans , Alopecia Areata/drug therapy , Valproic Acid/therapeutic use , beta Catenin , Axin Protein , Treatment OutcomeABSTRACT
The Wnt/ß-catenin pathway is critical to maintaining cell fate decisions. Recent study showed that liquid-liquid-phase separation (LLPS) of Axin organized the ß-catenin destruction complex condensates in a normal cellular state. Mutations inactivating the APC gene are found in approximately 80% of all human colorectal cancer (CRC). However, the molecular mechanism of the formation of ß-catenin destruction complex condensates organized by Axin phase separation and how APC mutations impact the condensates are still unclear. Here, we report that the ß-catenin destruction complex, which is constructed by Axin, was assembled condensates via a phase separation process in CRC cells. The key role of wild-type APC is to stabilize destruction complex condensates. Surprisingly, truncated APC did not affect the formation of condensates, and GSK 3ß and CK1α were unsuccessfully recruited, preventing ß-catenin phosphorylation and resulting in accumulation in the cytoplasm of CRCs. Besides, we propose that the phase separation ability of Axin participates in the nucleus translocation of ß-catenin and be incorporated and concentrated into transcriptional condensates, affecting the transcriptional activity of Wnt signaling pathway.
Subject(s)
Axin Signaling Complex , beta Catenin , Humans , Axin Signaling Complex/genetics , Axin Protein/genetics , Axin Protein/metabolism , beta Catenin/genetics , beta Catenin/metabolism , Phase Separation , Mutation/genetics , Wnt Signaling Pathway/genetics , Adenomatous Polyposis Coli Protein/genetics , Adenomatous Polyposis Coli Protein/metabolismABSTRACT
Mannose is a unique natural sugar that can be found in a variety of fruits and vegetables. During the past decades, mannose has been reported to be effective in promoting immune tolerance and suppressing inflammatory diseases. Metabolic dysfunction and altered inflammation have clear implications for the development and progression of inflammatory diseases. Herein, we intended to reveal the molecular mechanism of mannose in protecting against intestinal epithelial damage in experimental colitis. We showed that mannose treatment significantly attenuated dextran sodium sulfate (DSS)-induced intestinal barrier damage. The AMPK pathway was responsible for the mannose-mediated protective effect in DSS-induced intestinal epithelial damage. Mechanistically, mannose promoted the axis inhibition protein (AXIN)-based AMPK activation, thereby preventing mitochondrial dysfunction and tight junction disruption in response to the DSS challenge. Cumulatively, the results indicate the use of mannose as a novel approach to treat IBD and other diseases involving tight junction dysfunction. The therapeutic effect of mannose is related to its regulatory function in AMPK pathway activation.
Subject(s)
Colitis , Mannose , Animals , Mice , Mannose/therapeutic use , AMP-Activated Protein Kinases/metabolism , Axin Protein/metabolism , Axin Protein/pharmacology , Tight Junctions , Intestinal Mucosa , Dextran Sulfate/pharmacology , Colitis/chemically induced , Colitis/drug therapy , Colitis/metabolism , Mice, Inbred C57BL , Disease Models, AnimalABSTRACT
The ß-catenin has two intrinsically disordered regions in both C- and N-terminal domains that trigger the formation of phase-separated condensates. Variants in its C-terminus are associated with familial exudative vitreoretinopathy (FEVR), yet the pathogenesis and the role of these variants in inducing abnormal condensates, are unclear. In this study, we identified a novel heterozygous frameshift variant, c.2104-2105insCC (p.Gln703ProfsTer33), in CTNNB1 from a FEVR-affected family. This variant encodes an unstable truncated protein that was unable to activate Wnt signal transduction, which could be rescued by the inhibition of proteasome or phosphorylation. Further functional experiments revealed the propensity of the Gln703ProfsTer33 variant to form cytoplasmic condensates, exhibiting a lower turnover rate after fluorescent bleaching due to enhanced interaction with AXIN1. LiCl, which specifically blocks GSK3ß-mediated phosphorylation, restored signal transduction, cell proliferation, and junctional integrity in primary human retinal microvascular endothelial cells over-expressed with Gln703ProfsTer33. Finally, experiments on two reported FEVR-associated mutations in the C-terminal domain of ß-catenin exhibited several functional defects similar to the Gln703ProfsTer33. Together, our findings unravel that the C-terminal region of ß-catenin is pivotal for the regulation of AXIN1/ß-catenin interaction, acting as a switch to mediate nucleic and cytosolic condensates formation that is implicated in the pathogenesis of FEVR.