RESUMEN
Among myriads of distinct chemical modification in RNAs, the dynamic, reversible and fine-tuned methylation of N6-methyladenosine (m6A) is the most prevalent modification in eukaryotic mRNAs. This RNA mark is generated by proteins that act as m6A writers and can be reversed by proteins that act as m6A erasers. The RNA m6A modification is also mediated by another group of proteins capable of recognizing m6A that act as m6A readers. The m6A modification exerts direct control over the RNA metabolism including mRNA processing, mRNA exporting, translation initiation, mRNA stability and the biogenesis of long-non-coding RNA (LncRNA), thereby can influence various aspects of cell function. Evidently, m6A is intimately associated with cancer development and progression such as self-renewal capacity of cancer stem cells, proliferation, apoptosis and therapeutic resistance, and immune response. In this review, we will discuss the regulation and function of m6A, the various functions ascribed to these proteins and the emerging concepts that impact our knowledge of these proteins and their roles in the epitranscriptome. Conceivably, m6A may play pivotal roles in cytokine and immune response and carcinogenesis.
Asunto(s)
Adenosina/análogos & derivados , Carcinogénesis/metabolismo , Citocinas/metabolismo , Neoplasias/metabolismo , ARN/metabolismo , Adenosina/metabolismo , Animales , Carcinogénesis/patología , Humanos , Metilación , Neoplasias/patologíaRESUMEN
Myasthenia gravis (MG) is a chronic humoral immunity-mediated autoimmune disorder of the neuromuscular junction characterized by muscle weakness. Follicular helper T (Tfh) cells may be the key Th cell subset that promotes MG development, as their major function is helping B cell activation and Ab production. Aberrance of thymus-derived Tfh cells might be implicated in autoimmune diseases including MG; just how circulating Tfh cells, especially those from patients with a normal thymus, contribute to MG pathogenesis remains to be uncovered. In this article, we characterize a population of circulating CD4(+)CXCR5(+)PD-1(+) Tfh cells in ocular and generalized MG patients without thymic abnormalities and demonstrate that the circulating Tfh cells are significantly enriched in generalized MG patients but not in ocular MG patients compared with healthy subjects, whereas a proportion of follicular regulatory T cells decreased in MG patients. In addition, the frequency of plasma cells and B cells was higher and the serum levels of IL-6/IL-21 were also elevated in these MG patients. The activated Tfh1 and Tfh17 in Tfh cells are the major source for IL-21 production in MG patients. A strong correlation between Tfh cells and the plasma cell frequency and anti-acetylcholine receptor Ab titers was evident in generalized MG patients. In particular, we found that Tfh cells derived from MG patients promoted B cells to produce Abs in an IL-21 signaling-dependent manner. Collectively, our results suggest that circulating Tfh cells may act on autoreactive B cells and thus contribute to the development of MG in patients without thymic abnormalities.
Asunto(s)
Linfocitos B/inmunología , Miastenia Gravis/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/patología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miastenia Gravis/patología , Estudios ProspectivosRESUMEN
BACKGROUND: Inflammatory and immune responses triggered by brain ischemia worsen clinical outcomes of stroke and contribute to hemorrhagic transformation, massive edema, and reperfusion injury associated with intravenous alteplase. We assessed whether a combination of the immune-modulator fingolimod and alteplase is safe and effective in attenuating reperfusion injury in patients with acute ischemic stroke treated within the first 4.5 hours of symptom onset. METHODS AND RESULTS: In this multicenter trial, we randomly assigned 25 eligible patients with hemispheric ischemic stroke stemming from anterior or middle cerebral arterial occlusion to receive alteplase alone and 22 patients to receive alteplase plus oral fingolimod 0.5 mg daily for 3 consecutive days within 4.5 hours of the onset of ischemic stroke. Compared with patients who received alteplase alone, patients who received the combination of fingolimod with alteplase exhibited lower circulating lymphocytes, smaller lesion volumes (10.1 versus 34.3 mL; P=0.04), less hemorrhage (1.2 versus 4.4 mL; P=0.01), and attenuated neurological deficits in National Institute of Health Stroke Scales (4 versus 2; P=0.02) at day 1. Furthermore, restrained lesion growth from day 1 to 7 (-2.3 versus 12.1 mL; P<0.01) with a better recovery at day 90 (modified Rankin Scale score 0-1, 73% versus 32%; P<0.01) was evident in patients given fingolimod and alteplase. No serious adverse events were recorded in all patients. CONCLUSIONS: In this pilot study, combination therapy of fingolimod and alteplase was well tolerated, attenuated reperfusion injury, and improved clinical outcomes in patients with acute ischemic stroke. These findings need to be tested in further clinical trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02002390.
Asunto(s)
Edema Cardíaco/prevención & control , Fibrinolíticos/uso terapéutico , Clorhidrato de Fingolimod/uso terapéutico , Factores Inmunológicos/uso terapéutico , Daño por Reperfusión Miocárdica/prevención & control , Accidente Cerebrovascular/tratamiento farmacológico , Activador de Tejido Plasminógeno/uso terapéutico , Linfocitos B/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Fibrinolíticos/farmacología , Clorhidrato de Fingolimod/farmacología , Humanos , Factores Inmunológicos/farmacología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Proyectos Piloto , Recuperación de la Función/efectos de los fármacos , Accidente Cerebrovascular/patología , Linfocitos T/efectos de los fármacos , Activador de Tejido Plasminógeno/farmacología , Resultado del TratamientoRESUMEN
BACKGROUND/AIMS: Na+/H+ exchanger 1 (NHE1) is an important regulator of intracellular pH (pHi). High pHi is required for cell proliferation and differentiation. Our previous study has proven that the pHi of mesenchymal stem cells is higher than that of normal differentiated cells and similar to tumor cells. NHE1 is highly expressed in both mesenchymal stem cells and tumor cells. Targeted inhibition of NHE1 could induce differentiation of K562 leukemia cells. In the present paper we explored whether inhibition of NHE1 could induce differentiation of mesenchymal stem cells. METHODS: MSCs were obtained from human umbilical cord and both the surface phenotype and functional characteristics were analyzed. Selective NHE1 inhibitor cariporide was used to treat human umbilical cord-derived mesenchymal stem cells (hUC-MSCs). The pHi and the differentiation of hUC-MSCs were compared upon cariporide treatment. The putative signaling pathway involved was also explored. RESULTS: The pHi of hUC-MSCs was decreased upon cariporide treatment. Cariporide up-regulated the osteogenic differentiation of hUC-MSCs while the adipogenic differentiation was not affected. For osteogenic differentiation, ß-catenin expression was up-regulated upon cariporide treatment. CONCLUSION: Decreased pHi induced by cariporide differentially contributes to hUC-MSCs differentiation.
Asunto(s)
Diferenciación Celular/efectos de los fármacos , Guanidinas/farmacología , Espacio Intracelular/metabolismo , Células Madre Mesenquimatosas/citología , Sulfonas/farmacología , Cordón Umbilical/citología , Adipogénesis/efectos de los fármacos , Proteínas de Transporte de Catión/metabolismo , Muerte Celular/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Concentración de Iones de Hidrógeno , Espacio Intracelular/efectos de los fármacos , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Osteogénesis/efectos de los fármacos , Fenotipo , ARN Interferente Pequeño/metabolismo , Intercambiador 1 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/metabolismo , Regulación hacia Arriba/efectos de los fármacos , beta Catenina/metabolismoRESUMEN
Multidrug resistance (MDR) is a major problem facing patients with cancer. Although Neutrophil gelatinase-associated lipocalin (NGAL) is highly expressed in various cancers, the possible role of NGAL in MDR is still obscure. In this article, we evaluated the effect of NGAL on Rh123 accumulation in cancer cells. NGAL was first down-regulated by short hairpin RNA-mediated interference. In correlation with the reduced NGAL expression, intracellular Rh123 accumulation was significantly decreased. We finally observed that inhibiting both of the ERK1/2 and p38 MAPK could seriously down-regulate NGAL expression and also decrease the intracellular accumulation of Rh123, indicating that NGAL-mediated Rh123 accumulation is regulated by the phosphorylation of ERK1/2 and p38 MAPK. Pretreatment of MDA-MB-231 with NGAL recombinant protein and antibody had significant effects on the intracellular accumulation of Rh123, whereas little effect was observed in K562 cells treated with the same method, suggesting that NGAL was involved in the regulation of Rh123 accumulation in these two types of cancers, although different pathways. Here we provide new evidence that directly shows the possibility of small chemical substances Rh123 intracellular accumulation that is regulated by NGAL. These results suggest the possibility of NGAL involvement in drug transportation and cancer MDR formation, and indicate the potential of NGAL in cancer therapy.
Asunto(s)
Proteínas de Fase Aguda/metabolismo , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Colorantes Fluorescentes/metabolismo , Lipocalinas/metabolismo , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Rodamina 123/metabolismo , Proteínas de Fase Aguda/genética , Transporte Biológico , Línea Celular Tumoral , Técnicas de Silenciamiento del Gen , Humanos , Lipocalina 2 , Lipocalinas/genética , Proteínas Proto-Oncogénicas/genéticaRESUMEN
BACKGROUND: Chronic myeloid leukemia is a clonal myeloproliferative disorder disease in which BCR/ABL plays an important role as an oncoprotein and molecular target. Despite the success of targeted therapy using tyrosine kinase inhibitors, CML remains largely incurable, most likely due to the treatment resistance after firstly chemical therapy. So know well the unique molecular pathway of CML is very important. METHODS: The expressions of CD44 in different leukemia patients and cell lines were detected by real-time PCR and western blotting. The effects of CD44 on proliferation of K562 cells were determined using the MTT and colony formation assays, and even in a nude mouse transplantation model. Then, the cell cycle changes were detected by flow cytometric analysis and the early apoptosis of cells was detected by the annexin V/propidium iodide double-staining assay. The expressions of the cycles and apoptosis-related proteins p21, Cyclin D1 and Bcl-2 were analyzed by western blot and real-time PCR assay. Finally, the decreased nuclear accumulation of ß-catenin was detected by western blotting and immunefluorescence. RESULTS: Firstly, we showed that CD44 expression was increased in several kinds of leukemia patients and K562 cells. By contrast, the down-regulation of CD44 resulted in decreased proliferation with a G0/G1 arrest of cell cycle in K562 cells according to the MTT assay and the flow cytometric analysis. And no significant induction of both the early and late phases of apoptosis was shown by the annexin V-FITC and PI staining. During this process, p21 and cyclin D1 are the major causes for cell cycle arrest. In addition, we found CD44 down-regulation decreased the expression of ß-catenin and increased the expression of phosphorylated ß-catenin. The instability of Wnt/ß-catenin pathway induced by increased expression of p-ß-catenin resulted in a decreased nuclear accumulation in CD44 silenced K562 cells. In the nude mouse transplantation model, we also found the same results. CONCLUSIONS: These results show that K562 cells depend to a greater extent on CD44 for proliferation, and CD44 down-regulation may induce a cell cycle arrest through Wnt/ß-catenin pathway. CD44 blockade may be beneficial in therapy of CML.
RESUMEN
BACKGROUND: ALKBH5 is aberrantly activated and exerts critical roles in facilitating the development of glioblastoma. However, the underlying activation mechanism by which ALKBH5 protein is increased in glioblastoma is not completely understood. Our study aimed to elucidate the signaling pathways involved in mediating ALKBH5 protein stability. METHODS: The contribution of deubiquitinating enzymes (DUB) to the fluctuation of ALKBH5 protein expression was globally profiled with western blot analysis. Mass spectrometry and immunoprecipitation were performed to identify the USP36 and ALKBH5 interaction. The effects of USP36 on the stability of ALKBH5 were detected with in vivo and in vitro ubiquitination assays. Cell proliferation assays, neurosphere formation, limited dilution assay, and intracranial tumor growth assays were implemented to assess the collaborative capacities of USP36 and ALKBH5 in tumorigenesis. RESULTS: Ubiquitin-specific peptidase 36 (USP36), as a potential ALKBH5-activating DUB, played an essential role in stabilization of ALKBH5 and regulation of ALKBH5-mediated gene expression in glioblastoma. The depletion of USP36 drastically impaired cell proliferation deteriorated the self-renewal of GSCs and sensitized GSCs to temozolomide (TMZ) treatment. Furthermore, the deletion of USP36 substantially decreased the in vivo tumor growth when monitored by bioluminescence imaging. Our findings indicate that USP36 regulates the protein degradation and expression of ALKBH5, and the USP36-ALKBH5 axis orchestrates glioma tumorigenesis. CONCLUSION: Our findings identify USP36 as a DUB of ALKBH5 and its role in glioblastoma progression, which may serve as a potential therapeutic target for glioblastoma treatment.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/tratamiento farmacológico , Ubiquitina Tiolesterasa/genética , Ubiquitinación , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Proliferación Celular , Carcinogénesis , Transformación Celular Neoplásica , Línea Celular Tumoral , Desmetilasa de ARN, Homólogo 5 de AlkB/genética , Desmetilasa de ARN, Homólogo 5 de AlkB/metabolismoRESUMEN
Breast cancer is a leading cause of morbidity in women worldwide. neutrophil gelatinase-associated lipocalin (NGAL), a useful biomarker of ER negative (ER(-)) breast cancer, promotes local tumor invasion and lymph node metastasis. We first identified the distinctive expression of NGAL in two breast cancer cell lines MCF7 and MDA-MB-231 cells, and then confirmed NGAL as a critical inducer of metastasis. Finally, the transcriptional factor CCAAT enhancer-binding proteins ζ (C/EBP ζ) was overexpressed in MDA-MB-231 cells. Consistent with the effect of NGAL knockdown, C/EBP ζ overexpression caused the significant changes that could prevent cell metastasis. C/EBP ζ overexpression induced a strong decrease in NGAL and matrix metalloproteinases (MMPs) expressions as determined by quantitative real time PCR and Western blotting. To identify the potential role of C/EBP ζ on regulating of NGAL in breast cancer, we established the dual-luciferase reporter assay for NGAL in MDA-MB-231 cells cotransfected with C/EBP ζ. Promoter reporter assays determined that C/EBP ζ directly repressed the human NGAL gene promoter activity by inhibiting the NGAL transcription. Taken together, this work identified that the C/EBP ζ overexpression downregulated NGAL to inhibit migration and invasion of breast cancer, which could be used as a novel strategy for breast cancer therapy.
Asunto(s)
Proteínas de Fase Aguda/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Carcinoma/genética , Carcinoma/patología , Lipocalinas/genética , Proteínas Proto-Oncogénicas/genética , Factor de Transcripción CHOP/fisiología , Proteínas de Fase Aguda/metabolismo , Neoplasias de la Mama/metabolismo , Carcinoma/metabolismo , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Células HeLa , Humanos , Células Jurkat , Células K562 , Lipocalina 2 , Lipocalinas/metabolismo , Metástasis de la Neoplasia , Proteínas Proto-Oncogénicas/metabolismo , Factor de Transcripción CHOP/genética , Factor de Transcripción CHOP/metabolismo , Transfección , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Proteínas Supresoras de Tumor/fisiologíaRESUMEN
The interaction between calcineurin B homologous protein 2 (CHP2) and Na(+) /H(+) exchanger 1 (NHE1), two membrane proteins, is essential for protecting cells from serum deprivation-induced death. Although four putative EF-hands in CHP2 had been predicted for years, Ca²(+) -binding activities of these motifs have not been tested yet, their role in this process remain poorly understood. To identify Ca²(+) -binding motifs required for the stable formation of CHP2/NHE1 complexes, we developed a mutagenesis-based assay in PS120 cells. We found that (45) Ca²(+) bond to two EF-hand motifs (EF3 and 4) of CHP2 proteins with high affinity. Complex formation between CHP2 and the CHP2 binding domain of NHE1 resulted in a marked increase in the Ca²(+) -binding affinity of CHP2. Co-immunoprecipitation and distribution of GFP-tagged CHP2-EF3m/4m also indicated that Ca²(+) affected the membrane location of CHP2 to interact with NHE1. The C-terminal region of CHP2 contains a nuclear export sequence (NES). When the six leucines of NES were mutated to alanines, the resulting CHP2 protein was predominantly localized to the nucleus. Furthermore, mutation of the NES resulted in enhanced proliferation and oncogenic potential of HeLa cells. Together, these results show that calcium and NES control the subcellular distribution of CHP2 and then distinctively regulate cell proliferation.
Asunto(s)
Proteínas de Unión al Calcio/metabolismo , Proteínas de Transporte de Catión/metabolismo , Proliferación Celular , Motivos EF Hand/genética , Señales de Localización Nuclear/química , Intercambiadores de Sodio-Hidrógeno/metabolismo , Secuencia de Aminoácidos , Proteínas de Unión al Calcio/química , Línea Celular Transformada , Células HeLa/metabolismo , Humanos , Datos de Secuencia Molecular , Señales de Localización Nuclear/fisiología , Alineación de Secuencia , Intercambiador 1 de Sodio-HidrógenoRESUMEN
The effect of hypoxia on the differentiation of chronic myeloid leukaemic K562 cells were studied, as was the role of the NHE1 (Na+/H+ exchanger 1). Hypoxia induced differentiation of K562 cells as seen by modifications in their morphological features, up-regulation of C/EBPα (CCAAT/enhancer-binding protein α), and marked IL-8 (interleukin-8) release. Inhibition of NHE1 under hypoxia additionally enhanced the level of C/EBPα and further promoted leukaemic cells differentiation. Pharmacological inhibition of p38 MAPK (mitogen-activated protein kinase) also significantly suppressed C/EBPα expression under hypoxia conditions after NHE1 inhibition. These results indicate the enhancement of hypoxia-induced K562 differentiation by NHE1 inhibition, which may be due to up-regulation of C/EBPα via p38 MAPK signalling pathway, which suggests a possible therapeutic target of NHE1 under hypoxia microenvironment in the treatment of leukaemic diseases.
Asunto(s)
Proteínas de Transporte de Catión/metabolismo , Diferenciación Celular/efectos de los fármacos , Intercambiadores de Sodio-Hidrógeno/metabolismo , Proteína alfa Potenciadora de Unión a CCAAT/genética , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/genética , Hipoxia de la Célula , Cobalto/farmacología , Guanidinas/farmacología , Humanos , Concentración de Iones de Hidrógeno/efectos de los fármacos , Interleucina-8/genética , Interleucina-8/metabolismo , Células K562 , Leucemia/metabolismo , Leucemia/patología , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Transducción de Señal/efectos de los fármacos , Intercambiador 1 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidores , Intercambiadores de Sodio-Hidrógeno/genética , Sulfonas/farmacología , Regulación hacia Arriba/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Naâº/H⺠exchanger 1 (NHE1), an important regulator of intracellular pH (pH(i)) and extracellular pH (pH(e)), has been shown to play a key role in breast cancer metastasis. However, the exact mechanism by which NHE1 mediates breast cancer metastasis is not yet well known. We showed here that inhibition of NHE1 activity, with specific inhibitor Cariporide, could suppress MDA-MB-231 cells invasion as well as the activity and expression of MT1-MMP. Overexpression of MT1-MMP resulted in a distinguished increase in MDA-MB-231 cells invasiveness, but treatment with Cariporide reversed the MT1-MMP-mediated enhanced invasiveness. To explore the role of MAPK signaling pathways in NHE1-mediated breast cancer metastasis, we compared the difference of constitutively phosphorylated ERK1/2, p38 MAPK and JNK in non-invasive MCF-7 cells and invasive MDA-MB-231 cells. Interestingly, we found that the phosphorylation levels of ERK1/2 and p38 MAPK in MDA-MB-231 cells were higher than in MCF-7 cells, but both MCF-7 cells and MDA-MB-231 cells expressed similar constitutively phosphorylated JNK. Treating MDA-MB-231 cells with Cariporide led to decreased phosphorylation level of both p38 MAPK and ERK1/2 in a time-dependent manner, but JNK activity was not influenced. Supplementation with MAPK inhibitor (MEK inhibitor PD98059, p38 MAPK inhibitor SB203580 and JNK inhibitor SP600125) or Cariporide all exhibited significant depression of MDA-MB-231 cells invasion and MT1-MMP expression. Furthermore, we co-treated MDA-MB-231 cells with MAPK inhibitor and Cariporide. The result showed that Cariporide synergistically suppressed invasion and MT1-MMP expression with MEK inhibitor and p38 MAPK inhibitor, but not be synergistic with the JNK inhibitor. These findings suggest that NHE1 mediates MDA-MB-231 cells invasion partly through regulating MT1-MMP in ERK1/2 and p38 MAPK signaling pathways dependent manner.
Asunto(s)
Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proteínas de Transporte de Catión/metabolismo , Metaloproteinasa 14 de la Matriz/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Neoplasias de la Mama/enzimología , Femenino , Guanidinas/farmacología , Humanos , Metaloproteinasa 14 de la Matriz/genética , Inhibidores de la Metaloproteinasa de la Matriz , Invasividad Neoplásica , Transducción de Señal/efectos de los fármacos , Intercambiador 1 de Sodio-Hidrógeno , Relación Estructura-Actividad , Sulfonas/farmacología , Células Tumorales CultivadasRESUMEN
As a previously discovered target of DNA damage, Na+/H+ exchanger 1 (NHE1) plays a role in regulation of intracellular pH (pHi) through the extrusion of intracellular proton (H+) in exchange for extracellular sodium (Na+). Its abnormal expression and dysfunction have been reported in solid tumor and hematopoietic malignancies. Here, we reported that suppression of NHE1 in BCR-ABL+ hematopoietic malignancies' K562 cells treated with Etoposide was manipulated by miR-19 and c-MYC. Inhibition of miR-19 or c-MYC enhanced the expression of NHE1 and sensitized K562 cells to Etoposide in vitro. The in vivo nude mouse transplantation model was also performed to confirm the enhanced sensitivity of K562 cells to Etoposide by inhibiting the miR-19 or c-MYC pathway. TCGA analysis conferred a negative correlation between miR-19 level and leukemia patients' survival. Thus, our results provided a potential management by which the c-MYC-miRNA 19 pathway might have a crucial impact on sensitizing K562 cells to Etoposide in the therapeutic approaches.
Asunto(s)
Neoplasias Hematológicas , Leucemia Mielógena Crónica BCR-ABL Positiva , MicroARNs , Intercambiador 1 de Sodio-Hidrógeno/metabolismo , Animales , Etopósido/farmacología , Etopósido/uso terapéutico , Regulación Leucémica de la Expresión Génica , Humanos , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Ratones , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Regulación hacia ArribaRESUMEN
Wnt/ß-catenin signaling activates the transcription of target genes to regulate stem cells and cancer development. However, the contribution of epigenetic regulation to this process is unknown. Here, we report that Wnt activation stabilizes the epigenetic regulator KDM4C that promotes tumorigenesis and survival of human glioblastoma cells by epigenetically activating the transcription of Wnt target genes. KDM4C protein expression was upregulated in human glioblastomas, and its expression directly correlated with Wnt activity and Wnt target gene expression. KDM4C was essential for Wnt-induced gene expression and tumorigenesis of glioblastoma cells. In the absence of Wnt3a, protein kinase R phosphorylated KDM4C at Ser918, inducing KDM4C ubiquitination and degradation. Wnt3a stabilized KDM4C through inhibition of GSK3-dependent protein kinase R activity. Stabilized KDM4C accumulated in the nucleus and bound to and demethylated TCF4-associated histone H3K9 by interacting with ß-catenin, promoting HP1γ removal and transcriptional activation. These findings reveal that Wnt-KDM4C-ß-catenin signaling represents a novel mechanism for the transcription of Wnt target genes and regulation of tumorigenesis, with important clinical implications. SIGNIFICANCE: These findings identify the Wnt-KDM4C-ß-catenin signaling axis as a critical mechanism for glioma tumorigenesis that may serve as a new therapeutic target in glioblastoma.
Asunto(s)
Neoplasias Encefálicas/genética , Carcinogénesis/genética , Epigénesis Genética , Glioblastoma/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteínas Wnt/metabolismo , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Proliferación Celular/genética , Desmetilación del ADN , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Histonas/genética , Histonas/metabolismo , Humanos , Estabilidad Proteica , Factor de Transcripción 4/genética , Transcripción Genética , Ubiquitinación/genética , Vía de Señalización Wnt/genética , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
Brain metastasis is a major cause of cancer mortality, but its molecular mechanisms are severely understudied. In addition, little is known regarding the role of m6A reader YTHDF3 in human diseases. Here, we show that YTHDF3 overexpression clinically correlates with brain metastases in breast cancer patients. YTHDF3 promotes cancer cell interactions with brain endothelial cells and astrocytes, blood-brain barrier extravasation, angiogenesis, and outgrow. Mechanistically, YTHDF3 enhances the translation of m6A-enriched transcripts for ST6GALNAC5, GJA1, and EGFR, all associated with brain metastasis. Furthermore, overexpression of YTHDF3 in brain metastases is attributed to increased gene copy number and the autoregulation of YTHDF3 cap-independent translation by binding to m6A residues within its own 5' UTR. Our work uncovers an essential role of YTHDF3 in controlling the interaction between cancer cells and brain microenvironment, thereby inducing brain metastatic competence.
Asunto(s)
Adenosina/análogos & derivados , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/patología , Proteínas de Unión al ARN/metabolismo , Regulación hacia Arriba , Regiones no Traducidas 5' , Adenosina/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Ratones , Trasplante de Neoplasias , Análisis de SupervivenciaRESUMEN
Neuromyelitis optica (NMO) is a refractory autoimmune inflammatory disease of the central nervous system without an effective cure. Autologous bone marrowderived mesenchymal stem cells (BMMSCs) are considered to be promising therapeutic agents for this disease due to their potential regenerative, immune regulatory and neurotrophic effects. However, little is known about the cytological features of BMMSCs from patients with NMO, which may influence any therapeutic effects. The present study aimed to compare the proliferation, differentiation and senescence of BMMSCs from patients with NMO with that of age and sexmatched healthy subjects. It was revealed that there were no significant differences in terms of cell morphology or differentiation capacities in the BMMSCs from the patients with NMO. However, in comparison with healthy controls, BMMSCs derived from the Patients with NMO exhibited a decreased proliferation rate, in addition to a decreased expression of several cell cyclepromoting and proliferationassociated genes. Furthermore, the cell death rate increased in BMMSCs from patients under normal culture conditions and an assessment of the gene expression profile further confirmed that the BMMSCs from patients with NMO were more vulnerable to senescence. Plateletderived growth factor (PDGF), as a major mitotic stimulatory factor for MSCs and a potent therapeutic cytokine in demyelinating disease, was able to overcome the decreased proliferation rate and increased senescence defects in BMMSCs from the patients with NMO. Taken together, the results from the present study have enabled the proposition of the possibility of combining the application of autologous BMMSCs and PDGF for refractory and severe patients with NMO in order to elicit improved therapeutic effects, or, at the least, to include PDGF as a necessary and standard growth factor in the current in vitro formula for the culture of NMO patientderived BMMSCs.
Asunto(s)
Células Madre Mesenquimatosas/metabolismo , Neuromielitis Óptica/metabolismo , Apoptosis , Biomarcadores , Estudios de Casos y Controles , Ciclo Celular , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Senescencia Celular , Expresión Génica , Humanos , Inmunofenotipificación , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/patología , Neuromielitis Óptica/genética , Neuromielitis Óptica/patologíaRESUMEN
Aberrant activation of ß-catenin signaling is a critical driver for tumorigenesis, but the mechanism underlying this activation is not completely understood. In this study, we demonstrate a critical role of ß-catenin signaling in stabilization of enhancer of zeste homolog 2 (EZH2) and control of EZH2-mediated gene repression in oncogenesis. ß-Catenin/TCF4 activated the transcription of the deubiquitinase USP1, which then interacted with and deubiquitinated EZH2 directly. USP1-mediated stabilization of EZH2 promoted its recruitment to the promoters of CDKN1B, RUNX3, and HOXA5, resulting in enhanced enrichment of histone H3K27me3 and repression of target gene expression. In human glioma specimens, expression levels of nuclear ß-catenin, USP1, and EZH2 correlated with one another. Depletion of ß-catenin/USP1/EZH2 repressed glioma cell proliferation in vitro and tumor formation in vivo. Our findings indicate that a ß-catenin-USP1-EZH2 axis orchestrates the interplay between dysregulated ß-catenin signaling and EZH2-mediated gene epigenetic silencing during glioma tumorigenesis. SIGNIFICANCE: These findings identify the ß-catenin-USP1-EZH2 signaling axis as a critical mechanism for glioma tumorigenesis that may serve as a new therapeutic target in glioblastoma.
Asunto(s)
Carcinogénesis/patología , Proteína Potenciadora del Homólogo Zeste 2/química , Regulación Neoplásica de la Expresión Génica , Glioma/patología , Proteasas Ubiquitina-Específicas/metabolismo , beta Catenina/metabolismo , Animales , Carcinogénesis/genética , Carcinogénesis/metabolismo , Proliferación Celular , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Epigénesis Genética , Glioma/genética , Glioma/metabolismo , Humanos , Ratones , Ratones Desnudos , Pronóstico , Estabilidad Proteica , Tasa de Supervivencia , Células Tumorales Cultivadas , Proteasas Ubiquitina-Específicas/genética , Ensayos Antitumor por Modelo de Xenoinjerto , beta Catenina/genéticaRESUMEN
Soluble receptor for advanced glycation end products (sRAGE) is an anti-inflammatory factor that mitigates the proinflammatory effects of high mobility group box 1 (HMGB1). The aim of this study was to investigate whether Guillain-Barré syndrome (GBS)-related inflammation are mediated by sRAGE and HMGB1. We measured serum sRAGE, HMGB1, IL-6, and TNF-α levels in 86 patients with GBS and analysed associations between sRAGE or HMGB1 and clinical variables in these subjects. In addition, we determined cerebrospinal fluid sRAGE and HMGB1 levels in a cross-sectional study of 50 patients with GBS who had matched serum samples. We found serum sRAGE levels in patients with the acute motor axonal neuropathy (AMAN) subtype of GBS, but not other subtypes, were significantly lower than those in healthy controls, and were significantly correlated with GBS disability score and Erasmus GBS outcome score, while serum HMGB1, IL-6, and TNF-α levels in all subtypes of GBS were significantly higher than those in healthy controls. Moreover, increased sRAGE levels and decreased HMGB1 levels after treatment were observed. Our results showed that serum sRAGE may be a useful biomarker for inflammation in the AMAN GBS subtype, while HMGB1 may be related to the inflammatory process across all types of GBS.
RESUMEN
Intracerebral hemorrhage (ICH) leads to high rates of death and disability. The pronounced inflammatory reactions that rapidly follow ICH contribute to disease progression. Our recent clinical trial demonstrated that oral administration of an immune modulator fingolimod restrained secondary injury derived from initial hematoma, but the mechanisms remain unknown. In this study, we aim to investigate the effects of fingolimod on inflammatory mediators and vascular permeability in the clinical trial of oral fingolimod for intracerebral hemorrhage (ICH). The results showed that fingolimod decreased the numbers of circulating CD4(+) T, CD8(+) T, CD19(+) B, NK, and NKT cells and they recovered quickly after the drug was stopped. The plasma ICAM level was decreased and IL-10 was increased by fingolimod. Interestingly, fingolimod protected vascular permeability as indicated by a decreased plasma level of MMP9 and the reduced rT1%. In conclusion, modulation of systemic inflammation by fingolimod demonstrates that it is an effective therapeutic agent for ICH. Fingolimod may prevent perihematomal edema enlargement by protecting vascular permeability.
Asunto(s)
Permeabilidad Capilar/efectos de los fármacos , Hemorragia Cerebral/tratamiento farmacológico , Clorhidrato de Fingolimod/uso terapéutico , Inmunosupresores/uso terapéutico , Mediadores de Inflamación/sangre , Separación Celular , Citocinas/biosíntesis , Citocinas/efectos de los fármacos , Humanos , Linfocitos/efectos de los fármacos , Método Simple CiegoRESUMEN
Rheumatoid arthritis (RA) is a systemic autoimmune disease and collagen-induced arthritis (CIA) is an animal model for RA. Micheliolide (MCL) is a novel compound with strong anti-inflammatory effects. The present study was conducted to evaluate the therapeutic effects of MCL on RA. Mice were randomly divided into four groups and the CIA model mice were treated with methotrexate (MTX), MCL and dimethyl sulfoxide. A score associated with the severity of arthritis was assigned on alternate days from the 22nd day for 60 days. Histopathological changes and the serum levels of cytokines were measured on day 85. The results demonstrated that the MCL treatment group had arthritis scores lower than the CIA group and higher than the MTX group; compared with the CIA group, MCL and MTX significantly reduced the swelling of the paws and suppressed the degeneration of articular cartilage. Expression levels of macrophage colony-stimulating factor (M-CSF), tissue inhibitors of metalloproteinases-1 (TIMP-1) and complement component 5a (C5/C5a) were lower in the mice with arthritis compared with normal mice, however, following treatment with MCL and MTX, all the mice exhibited significant recovery to differing degrees. Unlike the MTX group, the MCL group failed to recover the level of soluble intercellular adhesion molecule-1. In addition, the cytokine of B-lymphocyte chemoattractant (BLC) solely presented in the MCL group. These results suggest that MCL may be considered for use as a novel therapeutic treatment against RA and that changes in the expression of cytokines C5/C5a, TIMP-1, M-CSF and BLC may underlie the mechanism by which MCL effects changes in this disease.
Asunto(s)
Antirreumáticos/farmacología , Artritis Experimental , Artritis Reumatoide/tratamiento farmacológico , Sesquiterpenos de Guayano/farmacología , Animales , Antirreumáticos/administración & dosificación , Artritis Reumatoide/metabolismo , Artritis Reumatoide/patología , Citocinas/sangre , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Inmunosupresores/farmacología , Masculino , Metotrexato/farmacología , Ratones , Sesquiterpenos de Guayano/administración & dosificaciónRESUMEN
While follicular helper T (Tfh) cells have been shown to be involved in many autoimmune diseases, the association of Tfh cells with the disease activity of neuromyelitis optica spectrum disorders (NMOSDs) remains unclear. In this study, the CD4(+)CXCR5(+)PD-1(+) Tfh cell population in peripheral blood mononuclear cells (PBMCs) obtained from NMOSD patients, age- and gender-matched healthy controls, and multiple sclerosis patients was compared by flow cytometry. The serum levels of IL-21, IL-6, IL-17, TNF-α and IL-10 were analyzed by ELISA assays. We found that in NMOSD, the Tfh cell frequency is higher than that of healthy subjects and multiple sclerosis (MS) patients. There are more Tfh cells in the relapsing stage than the remitting stage of NMOSD, thus demonstrating the close association of the Tfh cell population with disease activity. Methylprednisolone, which is used to control disease relapses, significantly decreased the proportion of Tfh cells in NMOSD patients.