ABSTRACT
In canonical Wnt/β-catenin signaling pathway, β-catenin/TCF4 (T-cell factor 4) interaction plays an important role in the pathogenesis and development of non-small cell lung cancer (NSCLC), and it is tightly associated with the proliferation, chemoresistance, recurrence and metastasis of NSCLC. Therefore, suppressing β-catenin/TCF4 interaction in Wnt/β-catenin signaling pathway would be a new therapeutic avenue against NSCLC metastasis. In this study, considering the principle of enzyme-linked immunosorbent assay (ELISA), an optimized high-throughput screening (HTS) assay was developed for the discovery of β-catenin/TCF4 interaction antagonists. Subsequently, this ELISA-like screening assay was performed using 2 μg/mL GST-TCF4 βBD and 0.5 μg/mL β-catenin, then a high Z' factor of 0.83 was achieved. A pilot screening of a natural product library using this ELISA-like screening assay identified plumbagin as a potential β-catenin/TCF4 interaction antagonist. Plumbagin remarkably inhibited the proliferation of A549, H1299, MCF7 and SW480 cell lines. More importantly, plumbagin significantly suppressed the β-catenin-responsive transcription in TOPFlash assay. In short, this newly developed ELISA-like screening assay will be vital for the rapid screening of novel Wnt inhibitors targeting β-catenin/TCF4 interaction, and this interaction is a potential anticancer target of plumbagin in vitro.
Subject(s)
Humans , Carcinoma, Non-Small-Cell Lung , Cell Line, Tumor , Enzyme-Linked Immunosorbent Assay , High-Throughput Screening Assays , Lung Neoplasms , Transcription Factor 4/genetics , beta Catenin/geneticsABSTRACT
Wnt/β-catenin signaling pathway plays an important role in the proliferation, growth, invasion, and metastasis of human cancers. Moreover, β-catenin/T-cell factor 4 (TCF4) interaction regulates the transcription of the key oncogenes in Wnt/β-catenin signaling pathway. Therefore, β-catenin/TCF4 interaction would be a promising therapeutic target for the development of highly selective anticancer agents. At present, most ongoing small-molecule inhibitors targeting β-catenin/TCF4 interaction, including PKF222-815, iCRT3/5/14, LF3, and sanguinarine, have been developed in preclinical studies for human cancer therapeutics. In this review, we summarized the research advances of up-to date inhibitors targeting β-catenin/TCF4 interaction, including the molecular structure and cellular functions of β-catenin in canonical Wnt signaling pathway. This review holds a hopeful avenue for the development of novel and highly selective Wnt inhibitors targeting β-catenin/TCF4 interaction for future anticancer strategy.
ABSTRACT
To develop a fluorescence polarization (FP)-based high-throughput screening (HTS) assay to identify novel small-molecule antagonists targeting β-catenin/TCF4 (T-cell factor 4) interaction, recombinant human β-catenin was expressed in Escherichia coli Rosetta (DE3) cells and purified by HisTrapTM column. The bioactivity of purified β-catenin was further analyzed by enzyme-linked immunosorbent assay (ELISA). According to FP principle, the β-catenin/TCF4 binding model was performed, and fluorescence isothiocyanate (FITC) labeled TCF4 peptide (FITC-TCF4) served as the molecular probe of adaptor for binding to β-catenin. The FITC-TCF4 and β-catenin working concentration were optimized, and the binding conditions (complex stability and dimethylsulfoxide (DMSO) tolerance) have been investigated yet for further hits screening. The results showed that recombinant human β-catenin was successfully expressed and purified β-catenin exhibited favorable bioactivity in ELISA binding assay. Subsequently, the FP-based HTS assay was performed using 20 nmol·L-1 FITC-TCF4 and 100 nmol·L-1 β-catenin. Under these optimized conditions, a high Z´factor of 0.88 was achieved in a 384-well format and this FP-based HTS assay was very stable with regard to DMSO. Through screening of a natural-based product library (NBPL) using the established FP-based HTS assay, three hits (sanguinarine, chelerythrine, and compound S720) were identified as potential β-catenin/TCF4 interaction antagonists. Taken together, we have successfully developed a simple, robust and reliable FP-based HTS assay for screening of novel antagonists targeting β-catenin/TCF4 interaction.
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Aim To investigate the synergy effects of deoxyschizandrin and gemcitabine (GEM) on the proliferation of HepG2 human hepatocellular carcinoma cells in vitro and the underlying mechanism. Methods CCK8 method and colony formation assay were used to detect the effects of deoxyschizandrin monotherapy, GEM monotherapy and combination therapy on the proliferation of HepG2 cells. Flow cytometry was used to detect the change of apoptosis rate of HepG2 cells after treatment with single drug or the combination use of two drugs. Western blot was performed to detect the expression of BCL2, BAX, pro-caspase3, caspase3, pro-caspase9, caspase9, ß-catenin and TCF-4. Results Deoxyschizandrin, GEM and combination group significantly inhibited the proliferation of HepG2 cells and promoted cell apoptosis. The effects of the combination group on HepG2 cells were significantly stronger than those of single-drug groups (P < 0. 05). Western blot results showed the expression of pro-caspase3 and pro-caspase9 was changed slightly within deoxyschizandrin, GEM and combination groups compared with that of normal control, while the expression of B C L 2, ß-catenin and TCF-4 protein expression was down-regulated significantly (P < 0. 05). The expression of B A X, cleaved-caspase3 and cleaved-caspase 9 protein increased significantly after treatment with deoxyschizandrin, GEM and combination group (P < 0. 05). Specially, the increasing effect of the expression of the protein in combined group was more significant than that of single drug groups (P < 0. 05). Conclusions The combination of deoxyschizandrin and GEM significantly inhibited the proliferation of HepG2 cells and induced cell apoptosis, as well as suppressed the ß-catenin/TCF-4 pathway.
ABSTRACT
Aryl hydrocarbon receptor (AhR) regulates both innate and adaptive immune responses by sensing a variety of small synthetic and natural chemicals, which act as its ligands. AhR, which is expressed in dendritic cells (DCs), regulates the differentiation of DCs. However, effects of AhR on the differentiation of DCs are variable due to the heterogeneity of DCs in cell surface marker expression, anatomical location, and functional responses. The plasmacytoid DCs (pDCs), one of DC subsets, not only induce innate as well as adaptive immune responses by secreting type I interferons and pro-inflammatory cytokines, but also induce IL-10 producing regulatory T cell or anergy or deletion of antigen-specific T cells. We showed here that AhR ligands indoxyl 3-sulfate (I3S) and indole-3-carbinol (I3C) inhibited the development of pDCs derived from bone marrow (BM) precursors induced by FMS-like tyrosine kinase 3 ligand (Flt3L). I3S and I3C downregulated the expression of signal transducer and activator of transcription 3 (STAT3) and E2-2 (Tcf4). In mice orally treated with I3S and I3C, oral tolerance to dinitrofluorobenzene was impaired and the proportion of CD11c⁺B220⁺ cells in mesenteric lymph nodes was reduced. These data demonstrate that AhR negatively regulates the development of pDCs from BM precursors induced by Flt3L, probably via repressing the expression of STAT3.
Subject(s)
Animals , Mice , Bone Marrow , Cell Differentiation , Cytokines , Dendritic Cells , Dinitrofluorobenzene , fms-Like Tyrosine Kinase 3 , Immune Tolerance , Interferon Type I , Interleukin-10 , Ligands , Lymph Nodes , Population Characteristics , Receptors, Aryl Hydrocarbon , STAT3 Transcription Factor , T-Lymphocytes , Vascular Endothelial Growth Factor Receptor-1ABSTRACT
Aim To investigate the alteration of Wnt/β-catenin signaling and sirtuins 1 in type 2 diabetic rats’ aorta and clarify its role in the development of di-abetes aortic disease. Methods The type 2 diabetes rat model was established by injection of streptozocin after five-week of high fat diet. The rats were randomly divided into control group, DM model group of 2 weeks, 4 weeks, 8 weeks and 12 weeks. Fasting blood glucose ( FBG ) , total cholesterol ( TC ) , triglyceride ( TG) , high density lipoprotein-cholesterol( HDL-C) , low density lipoprotein- cholesterol ( LDL-C ) and fast-ing insulin( FINS) levels were tested. HE staining was used to observe the pathological changes of aortal struc-tures. The alteration of Wnt2, β-catenin, TCF4, SIRT1 and sFRP2 in aortawas determined by Western blot and RT-PCR. Results Compared with control group, TC, TG, LDL-C levels of type 2 diabetic rats were significantly increased, HDL-C levels were signif-icantly reduced( P0. 05). But the expression of TCF4 and SIRT1 was enhanced continuously in DM compared with control group while sFRP2 decreased in the duration of DM development. Conclusions Wnt/β-catenin signa-ling pathway was activated in diabetic aortal injury by regulation of SIRT1 via sFRP2 . Further researches on its mechanism of actionin DM aorta injury may find a new therapeutic target for the disease.
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Aim To investigate the promoting apoptosis effect of artesunate( ART) on human colon cancer Lovo cells and its mechanisms. Methods MTT assay was performed to determine the anti-proliferative effect of artesunate. Flow cytometry assay and electron micros-copy( EM) were used to evaluate the apoptotic effect of artesunate. Luciferase reporter assay was introduced to measure the activation of Wnt/β-catenin pathway. Western blot was used to detect the pathway-related protein levels of β-catenin, GSK-3β,c-Myc and apop-tosis-related protein level of casepase-3 . Results Compared with the control group, the inhibitory rate of cell proliferation at 72 h and 320 μmol·L-1 ART was (78. 99 ± 1. 95 )% ( F =898. 301, P =0. 000 ); the cell apoptotic rate at 24 h and 160 μmol · L-1 ART was(19. 00 ± 0. 05)% and morphological signs of cell apoptosis were found by EM;the transcriptional activi-ty of TCF4/LEF at 24 h and 160 μmol·L-1 ART was (0. 36 ± 0. 30)%(F =470. 954,P <0. 01); the ex-pressions of caspase-3 and GSK-3β were significantly increased, whileβ-catenin and c-Myc were significant-ly decreased when treated with different concentrations of ART for 48 h ( P <0. 01 ) . Conclusion ART may significantly inhibit proliferation and promote apoptosis of Lovo cells probably by inactivating Wnt/β-catenin pathway.
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Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naive T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24+ cDC1 cells compared to in pDCs and CD172alpha+ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s).
Subject(s)
Animals , Mice , Antigen-Presenting Cells , Biological Phenomena , Bone Marrow , Dendritic Cells , Gene Expression , Homeostasis , Immune System , MicroRNAs , RNA Interference , T-Lymphocytes , Transcription FactorsABSTRACT
Aim To investigate the anti-proliferation effect of resveratrol (Res)on human colon cancer cells and dissect the possible mechanism underlaying this effect.Methods We introduced crystal violet staining and Western blot to analyse the anti-proliferation effect of Res on HCT1 1 6 cells.Then,we used flow cytome-try and Western blot assay to detect the Res induced apoptosis in HCT1 1 6 cells.Next,we employed the well established TCF4 /LEF luciferase reporter to meas-ure the effect of Res on Wnt/β-catenin signaling trans-duction.Finally,we took Western blot and PCR assay to analyse the effect of Res on the expression of β-cate-nin in HCT1 1 6 cells.Results Crystal violet staining and Western blot analysis showed that Res could inhib-it the proliferation of HCT1 1 6 cells in a concentration-and time dependent fashion.What’s more,Res could promote apoptosis in HCT1 1 6 cells.The transcriptional activities of TCF4 /LEF reporter were reduced by Res in a concentration-dependent fashion (P <0.05 when the concentration of Res was 20 μmol·L -1 ,and P <0.01 when the concentration of Res was 40 μmol·L -1 or 80 μmol·L -1 ).Res could decrease not only the protein level of β-catenin in HCT1 1 6 cells,but also the mRNA expression of β-catenin.Conclusion Res can inhibit the proliferation of HCT1 1 6 cells,which may be mediated at least by down-regulating the ex-pression of β-catenin to inhibit the Wnt/β-catenin sig-naling transduction.
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TCF4 (transcription factor 4; E2-2, ITF2) is a transcription factor that when haplo-insufficient causes Pitt-Hopkins Syndrome (PTHS), an autism-spectrum disorder that is associated with pervasive developmental delay and severe intellectual disability. The TCF4 gene is also a risk factor with highly significant linkage to schizophrenia, presumably via overexpression of the TCF4 gene product in the central nervous system. This review will present an overview of the clinical manifestations of PTHS and relate those clinical attributes to the underlying molecular genetics of TCF4. In order to provide a molecular biological context for the loss of function of TCF4 in PTHS, the review will also present a brief overview of the basic biochemistry of TCF4-mediated regulation of cellular and neuronal gene expression. In the final section of this review, I will discuss and speculate upon possible roles for the TCF4 transcription factor in neuronal function and comment upon how understanding these roles may give new insights into the molecular neurobiology of human cognition.
Subject(s)
Animals , Humans , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics , Disease Models, Animal , Facies , Hyperventilation/diagnosis , Intellectual Disability/diagnosis , Neurons/metabolism , Transcription, GeneticABSTRACT
Objective To investigate the expression of T cell factor-4 (TCF4) gene in dermal papilla cells of hair follicles.Methods The expression of TCF4 gene was examined by in situ hybridization in scalp tissues of patients with alopecia areata and normal human controls,The protein and mRNA exprcssions of TCF4 were detected by immunochemistry and RT-PCR method,respectively,in aggregated and non-aggregated human dermal papilla cells.ResultsAs shown by in situ hybridization,TCF4 gene was expressed in the dermal papilla cells from healthy controls,but not in those from patients with alopecia areata.Both cell immunochemistry and RT-PCR showed that TCF4 gene expressed in aggregated dermal papilla cells,but not in non-aggregated dermal papilla cells.ConclusionsTCF4 gene is expressed in dermal papilla cells.The growth cycle Of follicles may be related to wnt signal.
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Aim To explore the effect of gastrin17 on expression of ?-catenin/Tcf-4 pathway in colonic carcinoma cell line——Colo320WT.Methods Colo-320WT cells were treated with 10-8 mol?L-1 gastrin17 in time-dependent way(0、1、6、12、24、48 h),while treated with 10-6 mol?L-1 L365,260(gastrin17 receptor blocker) for 30 minutes and treated with gastrin17 again for 12 h. The expression levels of ?-catenin in TX-100 solution fraction(cytoplasmic) and TX-100 insolution fraction(cytoskeleton bound) of Colo320WT cells, and the expression levels of ?-catenin/Tcf-4 complex were detected by coimmunoprecipation and Western blot. The expression levels of c-Myc and cyclinD1 were assayed by Western blot.Results Expression levels of ?-catenin in TX-100 solution fraction were decreased apparently, but increased again by L365,260 blocking. Expression levels of ?-catenin in TX-100 insolution fraction were on the contrary. Expression levels of ?-catenin/Tcf-4 complex increased apparently.Expression levels of c-Myc and cyclinD1 in Colo320WT treated by gastrin17 were higher markedly than those of Colo320WT untreated and treated by L365,260.Conclusions Gastrin17 interacted with CCK-2R and effected significantly distribution of ?-catenin in Colo320WT and activated ?-catenin/Tcf-4 pathway which led to c-Myc and cyclinD1 high expression,the way gastrin17 decreased cell-cell cohesion and increased tumor cells invasion and metastasis further.
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ObjectiveTo clone TCF4 (T cell factor 4) gene and construct its eukaryotic expression vector. MethodsThe total RNA was extracted from the aggregated human dermal papilla cells. The full length cDNA encoding TCF4 was obtained by RT- PCR, digested by restriction enzyme, then inserted in the eukaryotic expression vector pcDNA3.0. The sequence and reading frame were confirmed by two restriction enzymes and sequencing. The recombinant vector TCF4/pcDNA3.0 was stably transfected into dermal papilla cells, and the expression changes of TCF4 gene were detected. ResultsTCF4 gene was cloned from dermal papilla cells and its eukaryotic expression vector was constructed. After the identification and sequencing, the reconstructed plasmid was confirmed containing the correct and full nucleotide sequence of TCF4 gene. After stable transfection, the mRNA and protein level of TCF4 gene were up-regulated in dermal papilla cells and the proliferation of dermal papilla cells was promoted. ConclusionThe expression vector TCF4/pcDNA3.0 was constructed successfully and could be expressed in the dermal papilla cells. TCF4 gene can promote the proliferation of the dermal papilla cells.