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Extracellular matrix (ECM) metabolism disorders in the inflammatory microenvironment play a key role in the pathogenesis of intervertebral disc degeneration (IDD). Interleukin-32 (IL-32) has been reported to be involved in the progression of various inflammatory diseases; however, it remains unclear whether it participates in the matrix metabolism of nucleus pulposus (NP) cells. Therefore, this study aimed to investigate the mechanism of IL-32 on regulating the ECM metabolism in the inflammatory microenvironment. RNA-seq was used to identify aberrantly expressed genes in NP cells in the inflammatory microenvironment. Western blotting, real-time quantitative PCR, immunohistochemistry and immunofluorescence analysis were performed to measure the expression of IL-32 and metabolic markers in human NP tissues or NP cells treated with or without tumor necrosis factor-α (TNF-α). In vivo, an adeno-associated virus overexpressing IL-32 was injected into the caudal intervertebral discs of rats to assess its effect on IDD. Proteins interacting with IL-32 were identified via immunoprecipitation and mass spectrometry. Lentivirus overexpressing IL-32 or knocking down Fat atypical cadherin 4 (FAT4), yes-associated protein (YAP) inhibitor-Verteporfin (VP) were used to treat human NP cells, to explore the pathogenesis of IL-32. Hippo/YAP signaling activity was verified in human NP tissues. IL-32 expression was significantly upregulated in degenerative NP tissues, as indicated in the clinical samples. Furthermore, IL-32 was remarkably overexpressed in TNF-α-induced degenerative NP cells. IL-32 overexpression induced IDD progression in the rat model. Mechanistically, the elevation of IL-32 in the inflammatory microenvironment enhanced its interactions with FAT4 and mammalian sterile 20-like kinase1/2 (MST1/2) proteins, prompting MST1/2 phosphorylation, and activating the Hippo/YAP signaling pathway, causing matrix metabolism disorder in NP cells. Our results suggest that IL-32 mediates matrix metabolism disorders in NP cells in the inflammatory micro-environment via the FAT4/MST/YAP axis, providing a theoretical basis for the precise treatment of IDD.
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Vía de Señalización Hippo , Interleucinas , Degeneración del Disco Intervertebral , Núcleo Pulposo , Ratas Sprague-Dawley , Transducción de Señal , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patología , Humanos , Animales , Degeneración del Disco Intervertebral/metabolismo , Interleucinas/metabolismo , Masculino , Ratas , Cadherinas/metabolismo , Proteínas Señalizadoras YAP/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Adulto , Células Cultivadas , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Persona de Mediana Edad , Femenino , Matriz Extracelular/metabolismoRESUMEN
BACKGROUND: FAT4 (FAT Atypical Cadherin 4) is a member of the cadherin-associated protein family, which has been shown to function as a tumor suppressor by inhibiting proliferation and metastasis. The Wnt/ß-catenin pathway activation is highly associated with PD-L1-associated tumor immune escape. Here, we report the mechanism by which FAT4 overexpression regulates anti-tumor immunity in cervical cancer by inhibiting PD-L1 N-glycosylation and cell membrane localization in a ß-catenin-dependent manner. METHODS: FAT4 expression was first detected in cervical cancer tissues and cell lines. Cell proliferation, clone formation, and immunofluorescence were used to determine the tumor suppressive impact of FAT4 overexpression in vitro, and the findings were confirmed in immunodeficient and immunocomplete mice xenografts. Through functional and mechanistic experiments in vivo and in vitro, we investigated how FAT4 overexpression affects the antitumor immunity via the ß-catenin/STT3/PD-L1 axis. RESULTS: FAT4 is downregulated in cervical cancer tissues and cell lines. We determined that FAT4 binds to ß-catenin and antagonizes its nuclear localization, promotes phosphorylation and degradation of ß-catenin by the degradation complexes (AXIN1, APC, GSK3ß, CK1). FAT4 overexpression decreases programmed death-ligand 1 (PD-L1) mRNA expression at the transcriptional level, and causes aberrant glycosylation of PD-L1 via STT3A at the post-translational modifications (PTMs) level, leading to its endoplasmic reticulum (ER) accumulation and polyubiquitination-dependent degradation. We found that FAT4 overexpression promotes aberrant PD-L1 glycosylation and degradation in a ß-catenin-dependent manner, thereby increasing cytotoxic T lymphocyte (CTL) activity in immunoreactive mouse models. CONCLUSIONS: These findings address the basis of Wnt/ß-catenin pathway activation in cervical cancer and provide combination immunotherapy options for targeting the FAT4/ß-catenin/STT3/PD-L1 axis. Schematic cartoons showing the antitumor immunity mechanism of FAT4. (left) when Wnts bind to their receptors, which are made up of Frizzled proteins and LRP5/6, the cytoplasmic protein DVL is activated, inducing the aggregation of degradation complexes (AXIN, GSK3ß, CK1, APC) to the receptor. Subsequently, stable ß-catenin translocates into the nucleus and binds to TCF/LEF and TCF7L2 transcription factors, leading to target genes transcription. The catalytically active subunit of oligosaccharyltransferase, STT3A, enhances PD-L1 glycosylation, and N-glycosylated PD-L1 translocates to the cell membrane via the ER-to-Golgi pathway, resulting in immune evasion. (Right) FAT4 exerts antitumor immunity mainly through following mechanisms: (i) FAT4 binds to ß-catenin and antagonizes its nuclear localization, promotes phosphorylation and degradation of ß-catenin by the degradation complexes (AXIN1, APC, GSK3ß, CK1); (ii) FAT4 inhibits PD-L1 and STT3A transcription in a ß-catenin-dependent manner and induces aberrant PD-L1 glycosylation and ubiquitination-dependent degradation; (iii) Promotes activation of cytotoxic T lymphocytes (CTL) and infiltration into the tumor microenvironment.
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Antígeno B7-H1 , Neoplasias del Cuello Uterino , beta Catenina , Animales , Femenino , Humanos , Ratones , Antígeno B7-H1/genética , beta Catenina/metabolismo , Cadherinas , Glucógeno Sintasa Quinasa 3 beta/genética , Microambiente Tumoral , Proteínas Supresoras de Tumor , Neoplasias del Cuello Uterino/genéticaRESUMEN
Periventricular neuronal heterotopia (PH) is one of the most common forms of cortical malformation in the human cortex. We show that human neuronal progenitor cells (hNPCs) derived from PH patients with a DCHS1 or FAT4 mutation as well as isogenic lines had altered migratory dynamics when grafted in the mouse brain. The affected migration was linked to altered autophagy as observed in vivo with an electron microscopic analysis of grafted hNPCs, a Western blot analysis of cortical organoids, and time-lapse imaging of hNPCs in the presence of bafilomycin A1. We further show that deficits in autophagy resulted in the accumulation of paxillin, a focal adhesion protein involved in cell migration. Strikingly, a single-cell RNA-seq analysis of hNPCs revealed similar expression levels of autophagy-related genes. Bolstering AMPK-dependent autophagy by metformin, an FDA-approved drug, promoted migration of PH patients-derived hNPCs. Our data indicate that transcription-independent homeostatic modifications in autophagy contributed to the defective migratory behavior of hNPCs in vivo and suggest that modulating autophagy in hNPCs might rescue neuronal migration deficits in some forms of PH.
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The metabolism and remodeling of alveolar bone are the most active among the whole skeletal system, which is related to the biological characteristics and heterogeneity of the bone mesenchymal stromal cells (MSCs). However, there is a lack of systematic description of the heterogeneity of MSC-derived osteoblastic lineage cells as well as their distinct osteogenic differentiation trajectory of alveolar bone. In this study, we constructed a single-cell atlas of the mouse alveolar bone cells through single-cell RNA sequencing (scRNA-seq). Remarkably, by comparing the cell compositions between the alveolar bone and long bone, we uncovered a previously undescribed cell population that exhibits a high expression of protocadherin Fat4 (Fat4+ cells) and is specifically enriched around alveolar bone marrow cavities. ScRNA-seq analysis indicated that Fat4+ cells may initiate a distinct osteogenic differentiation trajectory in the alveolar bone. By isolating and cultivating Fat4+ cells in vitro, we demonstrated that they possess colony-forming, osteogenic, and adipogenic capabilities. Moreover, FAT4 knockdown could significantly inhibit the osteogenic differentiation of alveolar bone MSCs. Furthermore, we revealed that the Fat4+ cells exhibit a core transcriptional signature consisting of several key transcription factors, such as SOX6, which are involved in osteogenesis, and further demonstrated that SOX6 is required for the efficient osteogenic differentiation of the Fat4+ cells. Collectively, our high-resolution single-cell atlas of the alveolar bone reveals a distinct osteogenic progenitor that may contribute to the unique physiological characteristics of alveolar bone.
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Osteogénesis , Análisis de Expresión Génica de una Sola Célula , Ratones , Animales , Osteogénesis/genética , Células de la Médula Ósea/metabolismo , Diferenciación Celular/fisiología , Huesos , Células CultivadasRESUMEN
Cell growth and patterning are critical for tissue development. Here we discuss the evolutionarily conserved cadherins, Fat and Dachsous, and the roles they play during mammalian tissue development and disease. In Drosophila, Fat and Dachsous regulate tissue growth via the Hippo pathway and planar cell polarity (PCP). The Drosophila wing has been an ideal tissue to observe how mutations in these cadherins affect tissue development. In mammals, there are multiple Fat and Dachsous cadherins, which are expressed in many tissues, but mutations in these cadherins that affect growth and tissue organization are context dependent. Here we examine how mutations in the Fat and Dachsous mammalian genes affect development in mammals and contribute to human disease.
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Cadherinas , Proteínas de Drosophila , Animales , Humanos , Cadherinas/genética , Cadherinas/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Crecimiento y Desarrollo , Proliferación Celular , Polaridad Celular/genética , Drosophila melanogaster , Mamíferos/genética , Mamíferos/metabolismoRESUMEN
The molecular landscapes of diffuse large B-cell lymphoma (DLBCL) remained to be comprehensively investigated with an urgent need to identify novel prognostic biomarkers guiding prognostic stratification and disease monitoring. Baseline tumor samples of 148 DLBCL patients were analyzed using targeted next-generation sequencing (NGS) for mutational profiling, whose clinical reports were retrospectively reviewed. In this cohort, the subgroup of old DLBCL patients (age at diagnosis > 60, N = 80) exhibited significantly higher Eastern Cooperative Oncology Group scores and International Prognostic Index than their young counterparts (age at diagnosis ≤ 60, N = 68). As revealed by the NGS results, PIM1 (43.9%), KMT2D (31.8%), MYD88 (29.7%), and CD79B (27.0%) were identified as the most frequently mutated genes. Aberrations of genes of the immune escape pathway were significantly enriched in the young subgroup, while the altered epigenetic regulators were more abundant in the old patients. FAT4 mutation was identified as a positive prognostic biomarker, associated with longer progression-free survival and overall survival in the entire cohort and the old subgroup, using the Cox regression analyses. However, the prognostic function of FAT4 was not reproduced in the young subgroup. We comprehensively analyzed the pathological and molecular characteristics of old and young DLBCL patients and demonstrated the prognostic value of FAT4 mutation, which requires further validation with sizable cohorts in future research.
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Linfoma de Células B Grandes Difuso , Humanos , Pronóstico , Estudios Retrospectivos , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Genómica , Biomarcadores , Cadherinas , Proteínas Supresoras de TumorRESUMEN
FAT4 is an extremely large atypical cadherin with crucial roles in the control of planar cell polarity (PCP) and regulation of the Hippo signaling pathway. Our study aims to clarify the FAT4 expression patterns, as well as the significance of FAT4 in predicting the prognosis and cancer immunity to non-small cell lung cancer (NSCLC). FAT4 mRNA and protein expressions were both underregulated in NSCLC and associated with poor prognosis in both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). In addition, overexpress FAT4 with jujuboside A (JUA) or knockdown FAT4 with siRNA regulated the metastasis of LUAD through MAPK pathways. Moreover, the FAT4 expression included multiple immunological components to promote an immunosuppressive tumor microenvironment (TME). Furthermore, a study of the TCGA-LUAD cohort's DNA methylation results showed that most FAT4 DNA CpG sites were typically hypermethylated in NSCLC relative to the normal lung tissue. The DNA CpG sites cg25879360 and cg26389756 of FAT4 were found to be strongly associated with FAT4 expression in LUAD through the correlation study. In conclusion, this is the first to report the potential function of FAT4 in NSCLC. Hence, FAT4 could be used as a promising prognostic and immunological biomarker for NSCLC.
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Adenocarcinoma del Pulmón , Carcinoma de Pulmón de Células no Pequeñas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Pulmón/patología , Carcinoma de Células Escamosas/patología , Pronóstico , Microambiente Tumoral/genética , Cadherinas/genética , Proteínas Supresoras de TumorRESUMEN
Objective: We performed a pan-cancer analysis to explore the potential mechanisms of FAT4 in 33 different tumors. Methods: In this study, we selected 33 types of cancers based on the datasets of TCGA (the cancer genome atlas). We analyzed the expression of FAT4 in tumor and normal tissues. Meanwhile, we analyzed the expression levels of FAT4 in tissues from tumors of different stages. Kaplan-Meier survival analysis, Tumor Mutational Burden (TMB), Microsatellite Instability (MSI), immune infiltration analysis, Gene set enrichment analysis (GSEA), and FAT4-related gene enrichment analysis were performed. Results: FAT4 expression in most tumor tissues was lower than in corresponding control tissues. FAT4 expression was different in different stages of bladder cancer (BLCA), kidney clear cell carcinoma (KIRC), and breast cancer (BRCA). In addition, the expression level of FAT4 in different types of tumors has an important impact on the prognosis of patients. FAT4 might influence the efficacy of immunotherapy via tumor burden and microsatellite instability. We observed a statistically positive correlation between cancer-associated fibroblasts and FAT4 expression in most tumors. GSEA of BLCA indicated that low FAT4 expression groups were mainly enriched in calcium signaling pathway and chemokine signaling pathway. GSEA analysis of KIRC suggested low FAT4 expression groups were mainly involved in olfactory transduction and oxidative phosphorylation. Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the role of FAT4 in the pathogenesis of cancer may be related to human papillomavirus infection, Hippo signaling pathway, PI3K-Akt signaling pathway, etc. Gene Ontology (GO) enrichment analysis further showed that most of these genes were related to the pathways or cell biology, such as peptidyl-tyrosine phosphorylation, cell junction assembly, protein tyrosine kinase activity, etc. Conclusion: Our study summarized and analyzed the antitumor effect of FAT4 in different tumors comprehensively, which aided in understanding the role of FAT4 in tumorigenesis from the perspective of clinical tumor samples. Pan-cancer analysis showed that FAT4 to be novel biomarkers for various cancers prognosis.
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Cadherinas/metabolismo , Neoplasias , Fosfatidilinositol 3-Quinasas , Proteínas Supresoras de Tumor/metabolismo , Cadherinas/genética , Línea Celular Tumoral , Humanos , Inestabilidad de Microsatélites , Neoplasias/genética , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Supresoras de Tumor/genéticaRESUMEN
Van Maldergem syndrome (VMLDS) is a recessive disease which affects multiple organs including the face, ear, and limb extremities. It can be caused by pathogenic variants in either the gene DCHS1 or FAT4. Diagnosis of VMLDS is complicated, especially regarding its similarity of symptoms to Hennekam syndrome, another disorder caused by FAT4 variants. Reported patients are two infantile siblings with multiple congenital anomalies, who deceased without clinical diagnosis. Whole exome sequencing was exploited for expanded carrier screening (ECS) of their parents, which revealed a novel splicing variant in the gene FAT4, NM_024582.6: c.7018+1G>A. In silico analysis of the variant indicates loss of canonical donor splice site of intron 6. This variant is classified as pathogenic based on ACMG criteria. Reverse phenotyping of patients resulted in likely diagnosis of VMLDS2. This study reaffirms the possibility of using ECS, leading to the genetic diagnosis of a rare disease with complicated clinical features.
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FAT atypical cadherin 4 (FAT4) has been identified as a tumor suppressor in lung cancers. However, no agent for lung cancer treatment targeting FAT4 has been used in the clinic. Jujuboside A (JUA) is a major active compound in Semen Ziziphi Spinosae. Semen Ziziphi Spinosae is a traditional Chinese herbal medicine used clinically for tumor treatment to improve patients' quality of life. However, the anti-lung cancer activity and the underlying mechanisms of JUA are not yet fully understood. Here, we demonstrated the anti-lung cancer activity of JUA in two lung cancer mice models and three non-small cell lung cancer (NSCLC) cell lines, and further illustrated its underlying mechanisms. JUA suppressed the occurrence and development of lung cancer and extended mice survival in vivo, and suppressed NSCLC cell activities through cell cycle arrest, proliferation suppression, stemness inhibition and senescence promotion. Moreover, JUA directly bound with and activated FAT4, subsequently activating FAT4-HIPPO signaling and inhibiting YAP nuclear translocation. Knockdown of FAT4 diminished JUA's effects on HIPPO signaling, YAP nuclear translocation, cell proliferation and cellular senescence. In conclusion, JUA significantly suppressed NSCLC tumorigenesis by regulating FAT4-HIPPO-YAP signaling. Our findings suggest that JUA is a novel FAT4 activator that can be developed as a promising NSCLC therapeutic agent targeting the FAT4-HIPPO-YAP pathway.
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Antineoplásicos Fitogénicos/farmacología , Cadherinas/agonistas , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Vía de Señalización Hippo/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Saponinas/farmacología , Proteínas Supresoras de Tumor/agonistas , Proteínas Señalizadoras YAP/metabolismo , Transporte Activo de Núcleo Celular , Animales , Cadherinas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Proteínas Supresoras de Tumor/metabolismoRESUMEN
INTRODUCTION: HOXB8 is a protein that was found to promote cancer proliferation and invasion. ILK is a protein kinase which has a role in carcinogenesis. FAT4 is a tumor homologue that has a role in EMT and autophagy regulation. AIM OF THE STUDY: To identify expression of Human HOXB8, Integrin-linked kinase (ILK1) and FAT homolog 4 (FAT4) in colorectal cancer (CRC) correlating their expression with pathological, prognostic and clinical parameters of CRC. MATERIAL AND METHODS: We assessed the expression of HOXB8, ILK and FAT4 in fifty CRC patients and ten samples from nearby non-neoplastic colonic mucosa using immunohistochemistry. RESULTS: The expression of HOXB8 and ILK in CRC was positively associated with high tumor grade, advanced tumor stage, lymph node involvement (p < 0.001), occurrence of distant metastases (p = 0.003 and 0.024 respectively), higher incidence of tumor recurrence (p = 0.03, p < 0.001 respectively), worse survival rates (p = 0.038 and 0.003 respectively). The expression of FAT4 in CRC was correlated with lower grade, early stage of the tumor, absence of lymph node involvement (p < 0.001) and lack of distant metastases (p = 0.011). High FAT4 expression was associated with absence of tumor recurrence (p < 0.001) and favorable survival rates (p < 0.001 and 0.003). CONCLUSIONS: High immunohistochemical expression of HOXB8 and ILK in addition to low immunohistochemical expression of FAT4 was associated with unfavorable prognostic and pathological parameters of CRC.
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MicroRNA-106b-5p (miR-106b-5p) is involved in the development of many cancers including colorectal cancer (CRC), and FAT4 is correlated with regulation of growth and apoptosis of cancer cells. The present study aimed to investigate the relation between FAT4 and miR-106b-5p and the underlying mechanism of the two on the development of CRC. Quantitative real-time PCR (qRT-PCR) assay and Western blot (WB) analysis were performed to detect the expressions of messenger RNAs (mRNAs), microRNAs (miRNAs) and proteins. The viability of CRC cells was detected by cell counting kit-8 (CCK-8). Scratch test and transwell assay were performed to measure the migration and invasion of CRC cell. Tumor angiogenesis was simulated by in vitro angiogenesis experiment. Dual-luciferase reporter assay was performed to verify the targeting relation between miR-106b-5p and FAT4. The study found that the expression of FAT4 was down-regulated and that of miR-106b-5p was up-regulated in CRC tissues. Overexpression of FAT4 resulted in decreased proliferation, migration, invasion and angiogenesis of CRC cells, whereas silencing of FAT4 led to the opposite results. In rescue experiment, miR-106b-5p partially reversed the function of FAT4 in CRC cells, thus playing a carcinogenic role by targeting FAT4 in the CRC cells.
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Cadherinas/metabolismo , Movimiento Celular , Neoplasias Colorrectales/metabolismo , MicroARNs/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Cadherinas/genética , Proliferación Celular , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Células HT29 , Humanos , MicroARNs/genética , Invasividad Neoplásica , Neovascularización Patológica , Transducción de Señal , Proteínas Supresoras de Tumor/genéticaRESUMEN
BACKGROUND: The adhesion molecule, FAT4, has a tumor suppressor function with a critical role in the epithelial-to-mesenchymal-transition (EMT) and anti-malignant growth in several cancers. No study has investigated yet its role in epithelial ovarian cancer (EOC) progression. In the present study, we examined the role of FAT4 in proliferation and metastasis, and its mechanisms of interaction in these processes. METHODS: We have performed cell viability, colony formation, and invasion assays in ovarian cancer cells treated with siRNA to knockdown FAT4 gene expression. The regulatory effects of FAT4 on proteins involved in apoptotic, Wnt, Hippo, and retinoblastoma signaling pathways were evaluated by Western blotting following FAT4 repression. Also, 426 ovarian tumor samples and 88 non-tumor samples from the Gene Expression Profiling Interactive Analysis (GEPIA) database were analyzed for the expression of FAT4. Pearson's correlation was performed to determine the correlation between FAT4 and the E2F5, cyclin D1, cdk4, and caspase 9 expressions. RESULTS: Lower expression of FAT4 was observed in ovarian cancer cell lines and human samples as compared to non-malignant tissues. This down-regulation seems to enhance cell viability, invasion, and colony formation. Silencing FAT4 resulted in the upregulation of E2F5, vimentin, YAP, ß-catenin, cyclin D1, cdk4, and Bcl2, and in the downregulation of GSK-3-ß, and caspase 9 when compared to control. Furthermore, regulatory effects of FAT4 on the EMT and aggressive phenotype seem to occur through Hippo, Wnt, and cell cycle pathways. CONCLUSION: FAT4 downregulation promotes increased growth and invasion through the activation of Hippo and Wnt-ß-catenin pathways.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Cadherinas/antagonistas & inhibidores , Factor de Transcripción E2F5/metabolismo , Transición Epitelial-Mesenquimal , Regulación Neoplásica de la Expresión Génica , Neoplasias Ováricas/patología , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/antagonistas & inhibidores , beta Catenina/metabolismo , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Femenino , Técnicas de Silenciamiento del Gen , Genes Supresores de Tumor , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Transducción de Señal , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Proteínas Señalizadoras YAPRESUMEN
Background: Sporadic medullary thyroid carcinoma (MTC) is a relatively uncommon neuroendocrine malignancy and the molecular tumorigenesis of its sporadic type (sMTC) is only partially understood. In this study, we performed a study focusing on the genomic and transcriptomic characterization of sMTC. Methods: Twenty-nine sMTC patients were included. Whole-exome sequencing (WES) was carried out in 18 patients, including both tumor samples and matched noncancerous tissues. Whole transcriptome sequencing (RNA-Seq) was performed in all 29 tumors. WES, RNA-Seq, and copy number alteration (CNA) data were analyzed. A Cell Counting Kit-8 (CCK-8) assay was used to evaluate cell proliferation. Results: Among the somatic mutations, RET was the only recurrently cancer-related mutated gene (5/18, 27.8%). In the germline, FAT1 and FAT4, two members of the FAT gene family, were identified as the two most common mutated genes. CNA analysis found that FAT1 and FAT4, both located on chromosome 4q, were also two of the genes most commonly affected by somatic chromosomal deletions (4/18, 22.2%). Using TT and MZ-CRC-1 cell lines, the CCK-8 assay showed that FAT1 and FAT4 knockdown could promote MTC cell proliferation. Based on the gene expression profile, patients were clustered into two molecular subtypes: the mesenchymal-like subtype is characterized by epithelial-mesenchymal transition, while the proliferative-like subtype is associated with enrichment of cell cycle pathways. Most events of structural recurrence (80%) occurred in the proliferative-like subtype. Conclusion: In addition to RET, these findings demonstrate that FAT1/FAT4 genomic alterations appear to be frequent in sMTC. Two molecular subtypes of sMTC with distinct biological behavior could be identified. However, these results need to be validated by larger samples and more comprehensive experiments in the future, especially for the frequency and function of FAT1/FAT4 germline variants.
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Carcinoma Medular/genética , Mutación , Proteínas Proto-Oncogénicas c-ret/genética , Glándula Tiroides/metabolismo , Neoplasias de la Tiroides/genética , Transcriptoma , Adolescente , Adulto , Anciano , Carcinoma Medular/metabolismo , Carcinoma Medular/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-ret/metabolismo , Glándula Tiroides/patología , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/patología , Secuenciación del ExomaRESUMEN
BACKGROUND: Colorectal cancer (CRC) has high mortality, and 5-fluorouracil (5-FU) is a common clinical chemotherapeutic drug. The current study aimed to investigate the role of FAT4 in chemosensitivity of CRC cells treated by 5-FU. METHODS: The immunohistochemistry and qRT-PCR was conducted to measure the FAT4 expression in CRC and adjacent tissues. The FAT4 expression was determined by qRT-PCR and Western blot, comparison of FAT expression between normal and several CRC cell lines was then made, so as to identify cell lines with the highest (LS174T) and the lowest (SW-620) expressions of FAT4. The effects of 5-FU stimulation at various doses on cell viability were determined by CCK-8, and the level of FAT4 was also measured. After FAT4 knockdown in LS174T or FAT4 overexpression in SW-620 with or without pretreatment of 5-FU (30 µg/mL), cell growth, colony formation, cell migration and invasion, angiogenesis were determined by flow cytometry, wound-healing, transwell assay and tube formation assay, respectively. The expression levels of epithelial-mesenchymal transition (EMT) markers were detected by qRT-PCR and Western blot. RESULTS: FAT4 was down-regulated in CRC tissues and cells, cell viability of CRC cells was decreased. The level of FAT4 was increased with the increase of 5-FU concentrations. Moreover, 5-FU stimulation increased FAT4 expression, and reduced cell proliferation, migration, invasion, angiogenesis and cell EMT process, furthermore, such effects of 5-FU stimulation could be enhanced by FAT4 overexpression but reversed by FAT4 knockdown. CONCLUSIONS: Upregulation of FAT4 could increase the sensitivity of CRC cells to 5-FU.
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In human, mutations of the protocadherins FAT4 and DCHS1 result in Van Maldergem syndrome, which is characterised, in part, by craniofacial abnormalities. Here, we analyse the role of Dchs1-Fat4 signalling during osteoblast differentiation in mouse. We show that Fat4 and Dchs1 mutants mimic the craniofacial phenotype of the human syndrome and that Dchs1-Fat4 signalling is essential for osteoblast differentiation. In Dchs1/Fat4 mutants, proliferation of osteoprogenitors is increased and osteoblast differentiation is delayed. We show that loss of Dchs1-Fat4 signalling is linked to increased Yap-Tead activity and that Yap is expressed and required for proliferation in osteoprogenitors. In contrast, Taz is expressed in more-committed Runx2-expressing osteoblasts, Taz does not regulate osteoblast proliferation and Taz-Tead activity is unaffected in Dchs1/Fat4 mutants. Finally, we show that Yap and Taz differentially regulate the transcriptional activity of Runx2, and that the activity of Yap-Runx2 and Taz-Runx2 complexes is altered in Dchs1/Fat4 mutant osteoblasts. In conclusion, these data identify Dchs1-Fat4 as a signalling pathway in osteoblast differentiation, reveal its crucial role within the early Runx2 progenitors, and identify distinct requirements for Yap and Taz during osteoblast differentiation.
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Cadherinas/fisiología , Osteoblastos/fisiología , Osteogénesis/genética , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Animales , Animales Recién Nacidos , Diferenciación Celular/genética , Células Cultivadas , Anomalías Craneofaciales/genética , Anomalías Craneofaciales/patología , Modelos Animales de Enfermedad , Embrión de Mamíferos , Femenino , Deformidades Congénitas del Pie/genética , Deformidades Congénitas del Pie/patología , Deformidades Congénitas de la Mano/genética , Deformidades Congénitas de la Mano/patología , Humanos , Discapacidad Intelectual/genética , Discapacidad Intelectual/patología , Inestabilidad de la Articulación/genética , Inestabilidad de la Articulación/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Embarazo , Transducción de Señal/genéticaRESUMEN
PURPOSE: To investigate the effect of miR-107 on the growth and metastasis of gastric cancer (GC) and elucidate the probable mechanisms. METHODS: The expression of miR-107 and FAT4 in GC tissues and cells were detected using qRT-PCR. Bioinformatics and dual luciferase reporter gene assays were used to analyze the relationship between miR-107 and FAT4. miR-NC, miR-107 inhibitor, pcDNA3.1-FAT4 and siRNA-FAT4 were transfected into AGS and MKN-45 GC cell lines, respectively. The proliferation and migration abilities of GC cells after transfection were evaluated using the MTT assay, scratch test and transwell assay. The expression of epithelial-mesenchymal transition (EMT) markers: E-cadherin, N-cadherin, vimentin and related proteins of the PI3K/AKT signaling pathway were determined using western blot. The xenograft tumors of nude mice were observed to assess the tumorigenicity of GC cells in vivo. RESULTS: MiR-107 was up-regulated, while FAT4 was down-regulated in GC tissues and cells (P < 0.05); FAT4 was targeted and negatively regulated by miR-107. Down-regulating miR-107 or up-regulating FAT4 inhibited the GC cells proliferation, migration, invasion and tumorigenicity, and could also reduce the expression of N-cadherin, vimentin, p-PI3K and p-Akt expression and up-regulate E-cadherin. CONCLUSIONS: miR-107 promotes growth and metastasis in GC via activation of PI3K-AKT signaling by targeting FAT4, which may be a target for GC treatment.
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Cadherinas/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Proteínas Supresoras de Tumor/genética , Animales , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Genes Reporteros , Humanos , Ratones , Interferencia de ARN , Neoplasias Gástricas/patologíaRESUMEN
Recent studies have identified FAT tumour suppressor homologue 4 (FAT4), an essential component of adherents junctions, involved in several cancers. However, its role in endometrial cancer (EC) remains unclear. In this study, we first analyzed the association between FAT4 expression and tumour stage, tumour type, and patient prognosis in 552 tumour samples and 35 non-tumour samples from The Cancer Genome Atlas (TCGA) database. The association of decreased FAT4 expression with advanced signature (lymph node metastasis, lymphovascular invasion and muscular infiltration) in EC patients was also confirmed by our own dataset. Stable FAT4 Knockdown promoted EC cell lines proliferation and invasion. FAT4 overexpression inhibited the parental cell phenotype. FAT4 silencing resulted in decreased phosphorylation of the LATS1/2 and YAP while increased YAP nuclear translocation which was associated with the promotion of proliferation and invasion. PCR array analysis of the negative control and shFAT4 HEC-1B cell lines revealed that the deubiquitinating enzyme USP51 was a FAT4 interacting target gene. Ablating USP51 by shRNA decreased cellular FAT4 protein level while overexpression of USP51 increased FAT4 protein level. Coimmunoprecipitation confirmed the direct binding of FAT4 and USP51 which was essential for FAT4's function in EC. The growth inhibitory effect of FAT4 was also attenuated by USP51 down-regulation. In conclusion, suppression of FAT4 by inactivation of deubiquitinating enzyme USP51 promoted proliferation and invasion of EC cells via inhibiting Hippo pathway.
RESUMEN
FAT4 mutations lead to several human diseases that disrupt the normal development of the kidney. However, the underlying mechanism remains elusive. In studying the duplex kidney phenotypes observed upon deletion of Fat4 in mice, we have uncovered an interaction between the atypical cadherin FAT4 and RET, a tyrosine kinase receptor essential for kidney development. Analysis of kidney development in Fat4-/- kidneys revealed abnormal ureteric budding and excessive RET signaling. Removal of one copy of the RET ligand Gdnf rescues Fat4-/- kidney development, supporting the proposal that loss of Fat4 hyperactivates RET signaling. Conditional knockout analyses revealed a non-autonomous role for Fat4 in regulating RET signaling. Mechanistically, we found that FAT4 interacts with RET through extracellular cadherin repeats. Importantly, expression of FAT4 perturbs the assembly of the RET-GFRA1-GDNF complex, reducing RET signaling. Thus, FAT4 interacts with RET to fine-tune RET signaling, establishing a juxtacrine mechanism controlling kidney development.