RESUMEN
BACKGROUND: Temporal lobe epilepsy (TLE) is the most common drug-resistant epilepsy in adults, with pathological mechanisms remaining to be fully elucidated. Fibroblast Growth Factor 13 (FGF13) encodes an intracellular protein involved in microtubule stabilization and regulation of voltage-gated sodium channels (VGSCs) function. FGF13 mutation has been identified in patients with inherent seizure, suggesting a potential association between FGF13 and the etiology of TLE. Here, we set to explore the pathological role of FGF13 in the etiology of TLE. RESULTS: We found that the expression of FGF13 was increased in the cortical lesions and CA1 region of sclerotic hippocampus and correlated with the seizure frequency in TLE patients. Also, Fgf13 expression was increased in the hippocampus of chronic TLE mice generated by kainic acid (KA) injection. Furthermore, Fgf13 knockdown or overexpression was respectively found to attenuate or potentiate the effects of KA on axonal length, somatic area and the VGSCs-mediated current in the hippocampal neurons. CONCLUSIONS: Taken together, these findings suggest that FGF13 is involved in the pathogenesis of TLE by modulating microtubule activity and neuronal excitability.
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Epilepsia del Lóbulo Temporal , Factores de Crecimiento de Fibroblastos , Animales , Ratones , Modelos Animales de Enfermedad , Epilepsia del Lóbulo Temporal/genética , Epilepsia del Lóbulo Temporal/patología , Factores de Crecimiento de Fibroblastos/genética , Hipocampo/metabolismo , Ácido Kaínico , ConvulsionesRESUMEN
The theory of evolution of tumor cell population has been established for nearly 40 years. It was widely accepted for research and clinical anti-tumor treatment. Recently, it was suggested that cancer stem cells are the unit of evolution. Considering recent advances on genesis of tumor and leukemia with ecological and evolutionary views, this article reviews origin and evolution of leukemia stem cells. Over the last few years, clinical and experimental data suggest there are two paths for the origin of leukemia stem cells: from a transformed hematopoietic stem cell or progenitor. The mechanisms of leukemia stem cell formation and clonal evolution were elucidated. Sub-clonal mutations and clonal architectures in leukemia were studied and a mosaic evolution pattern is described. Random evolution or non-inherited mutations of leukemia cells would accelerate the progression of malignant disease. Finally, the mosaic or network mechanism for leukemogenesis is also discussed.
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Evolución Clonal , Leucemia , Progresión de la Enfermedad , Células Madre Hematopoyéticas , Humanos , Mutación , Células Madre NeoplásicasRESUMEN
Feedback and feedforward widely exist in life system, both of them are the basic processes of control system. While the concept of feedback has been widely used in life science, feedforward regulation was systematically studied in neurophysiology, awaiting further evidence and mechanism in molecular biology and cell biology. The authors put forward a hypothesis about the feedforward regulation of membrane bound macrophage colony stimulation factor (mM-CSF) on the basis of their previous work. This hypothesis might provide a new direction for the study on the biological effects of mM-CSF on leukemia and solid tumors, and contribute to the study on other membrane bound cytokines.
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Retroalimentación Fisiológica , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Humanos , Leucemia , Biología de SistemasRESUMEN
The role of interleukin 17 (IL-17) to epilepsy-associated cortical tubers of tuberous sclerosis complex (TSC) is unknown. We investigated the expression patterns of the IL-17 and IL-17 receptor (IL-17R) in cortical tubers of TSC compared with normal control cortex (CTX). We found that IL-17 and IL-17R were clearly upregulated in cortical tubers at the protein levels. Immunostaining indicated that IL-17 was specifically distributed in the innate immunity cells (DNs, GCs, astrocytes, and microglia) and adaptive immunity cells (T-lymphocytes) as well as the endothelial cells of blood vessels. The overexpression and distribution patterns of IL-17 may be involved in the epileptogenicity of cortical tubers in TSC.
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Corteza Cerebral/inmunología , Interleucina-17/genética , Esclerosis Tuberosa/inmunología , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Niño , Preescolar , Epilepsia/etiología , Epilepsia/inmunología , Epilepsia/patología , Femenino , Humanos , Lactante , Interleucina-17/biosíntesis , Masculino , Receptores de Interleucina-17/biosíntesis , Receptores de Interleucina-17/genética , Esclerosis Tuberosa/complicaciones , Esclerosis Tuberosa/patologíaRESUMEN
Tuberous sclerosis complex (TSC) and focal cortical dysplasia type IIb (FCDIIb) are recognized as causes of intractable epilepsy. Transient receptor potential vanilloid receptor 1 (TRPV1), a member of the transient receptor potential family, is the capsaicin receptor and is known to be involved in peripheral nociception. Recent evidence suggested that TRPV1 may be a contributing factor in epileptogenicity. Here, we evaluated the expression of TRPV1 in the cortical lesions of TSC and FCDIIb relative to normal control cortex. TRPV1 was studied in epilepsy surgery cases with TSC (cortical tubers; n=12) and FCDIIb (n=12) using immunocytochemistry, confocal analysis, and Western blotting (WB). Immunohistochemical location of the TRPV1 was predominately detected in the abnormal cell types, such as dysmorphic neurons, balloon cells (BCs) and giant cells. Co-localization assays further revealed that cells expressing TRPV1 mainly had a neuronal lineage, apart from some BCs in FCDIIb, which obviously were of astrocytic lineage. The increased TRPV1 expression within the dysplastic cortex of TSC and FCDIIb was confirmed by WB. Interestingly, both immunohistochemical and WB data indicated that TRPV1 might have both cytoplasm and nuclear distribution, suggesting a potential nuclear role of TRPV1. The over-expression of TRPV1 in cortical lesions of TSC and FCDIIb suggested the possible involvement of TRPV1 in the intrinsic and increased epileptogenicity of malformations of cortical development associated epilepsy diseases and may represent a potential antiepileptogenic target. However, the current data are merely descriptive, and further electrophysiological investigation is needed in the future.
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Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Malformaciones del Desarrollo Cortical/metabolismo , Malformaciones del Desarrollo Cortical/patología , Canales Catiónicos TRPV/biosíntesis , Esclerosis Tuberosa/metabolismo , Esclerosis Tuberosa/patología , Adolescente , Western Blotting , Caspasa 3/biosíntesis , Caspasa 3/genética , Niño , Preescolar , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Masculino , Canales Catiónicos TRPV/genéticaRESUMEN
Evolutionary medicine can give rational explanation for metabolism diseases via ecology and evolutionary theory. Recently, the view of somatic cell macroevolution was used in the study on the genesis and development of tumors, which provided new insight in the research work on tumors. In this article, the well-adopted tumor therapy strategy, "Dancing with Cancer", was analyzed preliminarily from the point of co-evolution game theory, based on the non-classical immunology theory and genome theory. The importance of increasing host fitness by changing host life-style to enhance tolerance was emphasized, which is the basis of the Dancing with Cancer strategy. On the other hand, the spreading tumor cells are not equally malignant and spreading tumors should be treated as other chronic diseases. Finally, basic and clinical research should be strengthened to improve the efficiency of the "Dancing with Cancer" strategy.
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Evolución Biológica , Neoplasias/terapia , Teoría del JuegoRESUMEN
Relapse, which puzzled several generations of hematologists, is the bottle-neck of radical treatment for leukemias. The progress of Human Microbiome Project at the beginning of 21st century suggested that human body was a super-organism constituted by the core of human cells and symbiotic microorganisms. The elucidation and characterization of endogenous retrovirus and prion protein suggested the possible effects of co-evolutional microorganisms on human health. Recently, the elucidation of the roles of tunneling nanotubes in intercellular communication and transportation suggested a novel way for cellular communication and transport of oncogenic materials. The role and significance of in vivo cell fusion have been studied in more detail. On the other hand, donor cell leukemia was reported. All of these approaches provide novel insights for studying the mechanism of leukemia relapse. Based on previous work, the authors suggest the hypothesis: there are two possible mechanisms for the relapse of leukemias: the minimal residual disease (MRD) and intercellular transportation of oncogenic materials.
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Leucemia/patología , Fusión Celular , Humanos , Neoplasia Residual/patología , RecurrenciaRESUMEN
Nucleotides are new players in the intercellular communication network. P2X7 is a member of the P2X family of receptors, which are ATP-gated plasma membrane ion channels with diverse biological functions. Abnormal expression and dysfunction of P2X7 have been reported in leukemias. Here, we report a new P2X7 mutant (an A(559)-to-G substitution causing N187D P2X7) cloned from J6-1 leukemia cells. The characteristics of N187D P2X7 were studied by establishing stably transfected K562 cell lines. Our results show that N187D P2X7 required a higher concentration of agonist for its activation, leading to Ca(2+) influx (EC(50) = 293.3 ± 6.6 µm for the mutant and 93.6 ± 2.2 µm for wild-type P2X7) and ERK phosphorylation, which were not caused by differential cell-surface expression or related to high ATPase activity on the cell surface and in the extracellular space. K562 cells expressing this N187D mutant showed a proliferative advantage and reduced pro-apoptosis effects in vitro and in vivo. Furthermore, elevated angiogenesis and CD206-positive macrophage infiltration were found in tumor tissues formed by K562-M cells. In addition, higher expression of VEGF and MCP1 could be detected in tumor tissues formed by K562-M cells. Our results suggest that N187D P2X7, representing mutants hyposensitive to agonist, might be a positive regulator in the progression of hematopoietic malignancies.
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Regulación Leucémica de la Expresión Génica , Leucemia Experimental/genética , Mutación Missense , Receptores Purinérgicos P2X7/genética , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/farmacología , Animales , Western Blotting , Calcio/metabolismo , Línea Celular Tumoral , Progresión de la Enfermedad , Activación Enzimática/efectos de los fármacos , Femenino , Humanos , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Células K562 , Leucemia Experimental/metabolismo , Leucemia Experimental/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Receptores Purinérgicos P2X7/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Trasplante Heterólogo , Carga Tumoral/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Neuronal synapse is the critical structure of neuronal network. Immune system is mainly consisted of invisible network. Recently, evidence showed that leukocyte synapses between immune cells named as immunological synapses (IS), were formed under some functional conditions to form temporal local network. In fact, they are dynamic structures, which can be classified into synapse and kinase. Different leukocytes have different synapses. Inflammatory and leukemic cells showed special patterns of IS. Similar structure is also observed in some viral infected lymphocytes, which is called virological synapse (VS). This is one of the mechanisms for viral transmission, not only enhancing the transmission efficiency but also mediating the escape from antibody neutralization, leading persistent infection. Recently the flower-like poly synapses was reported by French scientists. This is a multi-tunneling nanotube flower-like structure on cell surface. We had observed this kind of structure in EB virus infected human leukemic cell line J6-2. In this paper, the structure and function of leukocyte synapses are reviewed combined with authors' own work. Their significance is discussed.
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Sinapsis Inmunológicas , Leucocitos/citología , Leucocitos/fisiología , Humanos , Sinapsis Inmunológicas/inmunología , Sinapsis Inmunológicas/fisiología , Leucocitos/inmunología , Leucocitos/virologíaRESUMEN
Immune and hemopoiesis are one of basic project of experimental hematology. Immune function is a essential activity of white blood cells. It was puzzled for the diversity and complexity of immune response. Polarized immune response of immune cells was discovered 30 years ago, which facilitates the study on differentiation of lymphocyte. Recently recognition on multifunctional polarized immune response of lymphocyte and monocyte/macrophage would promote to elucidate the regulatory network of immune cells, diversity and complexity of immune response as well as the study on hemopoiesis. In this paper the approach of multifunctional polarized immune response of lymphocyte, monocyte/macrophage and dendritic cells were reviewed, and their role, especially in cytokine storm and tumor pro-inflammation condition were discussed.
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Monocitos/citología , Monocitos/inmunología , Diferenciación Celular , Citocinas/inmunología , Citotoxicidad Inmunológica , Células Dendríticas/citología , Células Dendríticas/inmunología , HumanosRESUMEN
Nucleotides are new players in intercellular communication network. P2X family receptors are ATP-gated plasma membrane ion channels with diverse biological functions. Their distribution patterns and significance in pediatric leukemias have not been established. Here we investigated the expression of P2X receptors in BMMC samples from Chinese pediatric acute leukemias. Real-time PCR and Western blot results showed that P2X1, P2X4, P2X5 and P2X7 receptors were simultaneously over expressed in leukemias compared with controls, whereas P2X2, P2X3 and P2X6 were absent or marginally expressed in both groups. It was worth noting that the co-expression feature of them, especially between P2X4 and P2X7, could be observed and the highest expression of P2X7 was detected in relapsed patients. Moreover, concomitant decrease of P2X4, P2X5 and P2X7 expressions was observed at CR stage in a follow-up study. Functional P2X7 was also verified. These results suggested that P2X1, P2X4, P2X5 and P2X7 were hematopoiesis-related P2X receptors, and their signaling, especially for P2X7, might play important roles in pediatric leukemias. P2X receptors might co-operatively contribute to the malignant phenotype in human pediatric leukemias.
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Biomarcadores de Tumor/metabolismo , Leucemia/metabolismo , Receptores Purinérgicos P2/biosíntesis , Adolescente , Pueblo Asiatico , Niño , Preescolar , Humanos , Receptores Purinérgicos P2XRESUMEN
The success of yielding induced pluripotent stem (iPS) cells from human somatic cells demonstrates the important role of reprogramming in the formation of stem/progenitor cells and initiates the exploration of the origin of leukemia stem cells. In our previous work, we have found two types of leukemia, bona fide leukemia and non-bona fide leukemia. Different leukemias originate from different leukemia stem/progenitor cells which are critical to the genesis and evolution of leukemia. Bona fide leukemia and non-bona fide leukemia originate from leukemia stem cells and progenitor cells, respectively. Recent research suggests that different types of leukemia are influenced by the reprogramming state of their origin cells.
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Reprogramación Celular , Leucemia/genética , Células Madre Neoplásicas , Células Madre , Diferenciación Celular , Humanos , Células Madre Pluripotentes InducidasRESUMEN
Up to date, eight types of human herpes viruses have been identified, all of which are ubiquitous, and usually establish latent infection in the host after primary infection. Since most of the herpes viruses are maintained in an asymptomatic form, they are often neglected. However, under some circumstances, these herpes viruses can cause fatal or severe diseases. Furthermore, the association of herpes viruses with hematopoietic malignancies is attracting researchers' attention. With the extensive development of hematopoietic stem cell and organ transplantation, reports regarding transplantation failure and complication caused by infection of human herpes virus has been increasing. Cytokine storm was firstly suggested as the mechanism of graft-versus-host diseases. In recent years, which has also been applied in the pathogenesis research of inflammation, and is supposed to play an important role in severe virus infection. In this paper, through discussing the possible role of latent infection of human herpes virus in the failure or complication of bone marrow or hematopoietic stem cell transplantation, and in refractory leukemia, the function and significance of latent infection of human herpes virus and the cytokine storm it caused were investigated.
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Citocinas/inmunología , Sistema Hematopoyético/inmunología , Sistema Hematopoyético/virología , Infecciones por Herpesviridae , Humanos , Latencia del VirusRESUMEN
The membrane form of macrophage colony-stimulating factor (mM-CSF) is an alternative splicing variant of this cytokine. Although its high expression was detected in hematopoietic malignancies, its physiologic and pathologic roles in hematopoietic system have not been established. In this report, stable transfectant clones expressing mM-CSF (Namalwa-M and Ramos-M) were obtained, which showed reduced proliferation potential in vitro. Moreover, the in vivo study showed that Namalwa-M and Ramos-M exhibited enhanced oncogenicity in tumor size in nude mice model, which could be inhibited by M-CSF monoclonal antibody. A remarkable increase in infiltrating macrophage and the vessel densities was found in tumor tissues formed by lymphoma cell lines that stably expressed mM-CSF, which suggested the involvement of macrophages in this process. The in vitro results using coculture system showed that macrophages could promote Namalwa-M and Ramos-M proliferation and activate extracellular signal-regulated kinase/mitogen-activated protein kinase signal pathway. In addition, the expression of murine origin vascular endothelial growth factor, basic fibroblast growth factor, and hepatocyte growth factor was elevated in Namalwa-M formed tumor tissues. These results suggested that mM-CSF should be a positive regulator in the development of hematopoietic malignancies by abnormally activating infiltrating macrophages, which in turn promote the malignant development. Thus, mM-CSF may be a critical linker between macrophages and malignant cells in the development of hematopoietic malignancies.
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Membrana Celular/metabolismo , Sistema Hematopoyético/citología , Sistema Hematopoyético/metabolismo , Factor Estimulante de Colonias de Macrófagos/metabolismo , Macrófagos/metabolismo , Animales , Línea Celular Tumoral , Femenino , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Sistema de Señalización de MAP Quinasas , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Transducción de Señal , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
As pioneer of tumor stem cell research, leukemia stem cell research has not only important theoretical significance, but also clinical application potential. The survival and development of stem cells are directly impacted by their microenvironment. The research on leukemia stem cells and their microenvironment are now becoming a hot topic. The author presumes that stem cells are a population with heterogenecity and hierarchy; any single cell from the population is difficult to form a clone; the interaction between the leukemia stem cell and its microenvironment can be described by the concept of leukemia stem cell niche. In this article, the leukemia cell population with heterogenecity and hierarchy as well as leukemia stem cell niche were summarized and discussed.
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Leucemia/patología , Células Madre Neoplásicas/patología , Nicho de Células Madre/citología , Células del Estroma/inmunología , Línea Celular Tumoral , Humanos , Leucemia/genética , Células Madre Neoplásicas/metabolismo , Células del Estroma/citologíaRESUMEN
J6-1 cell line is the first leukemic cell line established in China. It is a multi-clone cell line infected with both EBV and HHV-6. Many cytokines, receptors and other genes were cloned from J6-1 cell line since its establishment 30 years ago. Valuable information on leukemic characteristics and functions were obtained from the studies on this cell line, which could be categorized into several research subjects. These achievements implied the unique research value of multi-clone cell lines. This comment focuses attention on research advance of the J6-1 leukemic cell line in 30 years, including heterogeneity and multi-cloning of J6-1 cells, survival mechanism of J6-1 cell populations, abnormal intercellalar communication of J6-1 cells with its significance and inspiration from J6-1 cell line.
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Transformación Celular Neoplásica , Leucemia/patología , Línea Celular Tumoral , Células Clonales , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 6/inmunología , HumanosRESUMEN
Murine beta-defensin 2 (MBD2) is a small antimicrobial peptide of the innate immune system. Recent study showed that MBD2 could not only recruit immature dendritic cells but also activate them by Toll-like receptor 4 and thus may provide a critical link between the innate immune system and the adaptive immune response. In this report, we examined the antileukemia activity of MBD2 in a murine model of acute lymphoid leukemia (ALL) L1210. L1210 cells were engineered to secrete biologically functional MBD2. MBD2-modified L1210 (L1210-MBD2) showed significantly reduced leukemogenecity, resulting in a 80% rate of complete leukemia rejection. Inoculation of mice with L1210-MBD2 induced enhanced CTL and natural killer (NK) activity and augmented interleukin-12 and IFN-gamma production. All the recovered mice from the inoculation showed a protective immunity to the following challenge with parental L1210 cells and generate leukemia-specific memory CTL. Vaccines with irradiated L1210-MBD2 cells could cure 50% leukemia-bearing mice. Depletion of CD8+ T cells but not CD4+ T cells completely abrogated the antileukemia activity of MBD2. Interestingly, NK cells were also required for the MBD2-mediated antileukemia response, although ALL generally display a high degree of resistance to NK-mediated lysis. Our results suggest that MBD2 can activate both innate and adaptive immunity to generate potent antileukemia response, and MBD2 immunotherapy warrants further evaluation as a potential treatment for ALL.
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Vacunas contra el Cáncer/inmunología , Leucemia Linfoide/inmunología , Leucemia Linfoide/terapia , beta-Defensinas/inmunología , Enfermedad Aguda , Animales , Formación de Anticuerpos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas , Femenino , Inmunidad Innata , Memoria Inmunológica , Células Asesinas Naturales , Ratones , Transducción GenéticaRESUMEN
The cDNA encoding N-terminal three immunoglobin-like domains of human M-CSFR was linked to His-tag and endoplasmic reticulum retention sequence (KDEL) before being inserted into the genome of tobacco plant, Nicotiana tabacum cv. NC-89, by Agrobacterium tumefaciens-mediated transformation. The insertion and expression of target gene were confirmed by PCR, ELISA, and Western blot. The recombinant M-CSFsR reached a maximum expression level of 1.92% of total soluble protein in transgenic tobacco plant leaf tissues. The recombinant M-CSFsR could be purified through a one-step IMAC process and its bioactivity was confirmed by the inhibition of colony formation of J6-1 cells. The results suggested that we successfully expressed a high level of bioactive human M-CSFsR in tobacco plants.
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Expresión Génica , Nicotiana/genética , Plantas Modificadas Genéticamente/genética , Receptor de Factor Estimulante de Colonias de Macrófagos/biosíntesis , Proteínas Recombinantes de Fusión/biosíntesis , Línea Celular , Humanos , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Estructura Terciaria de Proteína/genética , Receptor de Factor Estimulante de Colonias de Macrófagos/genética , Receptor de Factor Estimulante de Colonias de Macrófagos/aislamiento & purificación , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/farmacología , Nicotiana/metabolismoRESUMEN
OBJECTIVE: To clone the entire coding sequence and analyze the function of P2X7 receptor of J6-1 human leukemia cells. METHODS: The entire coding sequence of P2X7 receptor was amplified by RT-PCR and then inserted into pTARGET plasmid to construct an eukaryotic expressing plasmid followed by DNA sequencing. HEK293 cells stably expressing P2X7 receptor were obtained after transfection and screening, and confirmed by RT-PCR and Western blotting. The bleb formation upon agonist stimulation was observed under phase contrast microscope. RESULTS: The entire coding sequence of P2X7 receptor of J6-1 cells was successfully cloned. DNA sequencing analysis revealed a substitution of G559, for A559, causing a substitution of Glu187 for Gln187. The P2X7 receptor derived from J6-1 cells could be functionally expressed in HEK293 cells, in which bleb formation could be detected upon stimulation. CONCLUSIONS: The entire coding sequence of P2X7 receptors was successfully cloned from J6-1 leukemia cells. Other unknown mechanism may contribute to the dysfunction of P2X7 receptor in these cells.
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Clonación Molecular , Leucemia/genética , Receptores Purinérgicos P2/fisiología , Línea Celular Tumoral , ADN Complementario/genética , Expresión Génica , Humanos , Leucemia/metabolismo , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2X7 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , TransfecciónRESUMEN
The P 2 X 7 nucleotide receptor is an adenosine 5'-triphosphate (ATP)-gated ion channel, which induces cation channel opening imparting significant permeability to Ca(2+), and is widely expressed in cells of hematopoietic origin. Our previous report showed that P 2 X 7-mediated calcium response was absent in three Epstein-Barr virus (EBV)-positive and P 2 X 7 positive cell lines. In this report, we detected the cell surface ATPase activity, which contributes to the hydrolysis of extracellular ATP, and the expression of CD 39, which is the main source of ATPase on hematopoietic cells, in these cell lines. Then, we tried to restore the P 2 X 7-mediated calcium response in LCL-H and J 6-1 cells by either increasing the concentration of agonist or suppressing the ATPase activity by betagammaMeATP, a synthetic poorly metabolizable ATP analogue. The results showed that LCL-H and J 6-1 cells had higher levels of ATPase activity and CD 39 expression. The treatment of 300 microM betagammaMeATP efficiently inhibited the ATPase activity on LCL-H and J 6-1 cells. Both elevation of agonist concentration (10mM ATP or 1mM BzATP) and pretreatment with 300 microM betagammaMeATP followed by stimulation with normal concentration of agonists (1mM ATP or 0.1mM BzATP) could cause P 2 X 7-mediated calcium response in LCL-H but neither in J 6-1 cells. These results suggested that multiple mechanisms contributed to the loss of the P 2 X 7-mediated calcium response. CD 39-associated high ATPase activity contributed to the loss of the P 2 X 7-mediated calcium response in LCL-H cells, while additional mechanism(s) existed in J 6-1 cells.