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1.
J Radiat Res ; 65(2): 177-186, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38155365

RESUMO

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive joint inflammation, resulting in cartilage destruction and bone erosion. It was reported that low-dose radiation modulates immune disease. Here, we investigated whether low-dose whole-body irradiation has preventive and therapeutic effects in collagen-induced RA (CIA) mouse models. Fractionated low-dose irradiation (0.05 Gy/fraction, total doses of 0.1, 0.5 or 0.8 Gy) was administered either concurrently with CIA induction by Type II collagen immunization (preventive) or after CIA development (therapeutic). The severity of CIA was monitored using two clinical parameters, paw swelling and redness. We also measured total Immunoglobulin G (IgG) and inflammatory cytokines (interleukine (IL)-6, IL-1ß and tumor necrosis factor-alpha (TNF-α)) in the serum by enzyme-linked immunosorbent assay, and we evaluated histological changes in the ankle joints by immunohistochemistry and hematoxylin and eosin staining. Low-dose irradiation reduced CIA clinical scores by up to 41% in the preventive model and by 28% in the therapeutic model, while irradiation in the preventive model reduced the typical CIA incidence rate from 82 to 56%. In addition, low-dose irradiation in the preventive model decreased total IgG by up to 23% and decreased IL-1ß and TNF-α by 69 and 67%, and in the therapeutic model, decreased total IgG by up to 35% and decreased IL-1ß and IL-6 by 59 and 42% with statistical significance (P < 0.01, 0.05 and 0.001). Our findings demonstrate that low-dose radiation has preventive and therapeutic anti-inflammatory effects against CIA by controlling the immune response, suggesting that low-dose radiation may represent an alternative therapy for RA, a chronic degenerative immune disease.


Assuntos
Artrite Experimental , Artrite Reumatoide , Camundongos , Animais , Fator de Necrose Tumoral alfa , Irradiação Corporal Total , Artrite Experimental/radioterapia , Artrite Experimental/tratamento farmacológico , Citocinas , Artrite Reumatoide/radioterapia , Artrite Reumatoide/induzido quimicamente , Artrite Reumatoide/tratamento farmacológico , Interleucina-6 , Colágeno , Imunoglobulina G/efeitos adversos
2.
J Alzheimers Dis ; 95(3): 1263-1272, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37638435

RESUMO

BACKGROUND: Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disease resulting from extracellular and intracellular deposits of amyloid-ß (Aß) and neurofibrillary tangles in the brain. Although many clinical studies evaluating pharmacological approaches have been conducted, most have shown disappointing results; thus, innovative strategies other than drugs have been actively attempted. OBJECTIVE: This study aims to explore low-dose radiation therapy (LDRT) for the treatment of patients with AD based on preclinical evidence, case reports, and a small pilot trial in humans. METHODS: This study is a phase II, multicenter, prospective, single-blinded, randomized controlled trial that will evaluate the efficacy and safety of LDRT to the whole brain using a linear accelerator in patients with mild AD. Sixty participants will be randomly assigned to three groups: experimental I (24 cGy/6 fractions), experimental II (300 cGy/6 fractions), or sham RT group (0 cGy/6 fractions). During LDRT and follow-up visits after LDRT, possible adverse events will be assessed by the physician's interview and neurological examinations. Furthermore, the effectiveness of LDRT will be measured using neurocognitive function tests and imaging tools at 6 and 12 months after LDRT. We will also monitor the alterations in cytokines, Aß42/Aß40 ratio, and tau levels in plasma. Our primary endpoint is the change in cognitive function test scores estimated by the Alzheimer's Disease Assessment Scale-Korea compared to baseline after 6 months of LDRT. CONCLUSIONS: This study is registered at ClinicalTrials.gov [NCT05635968] and is currently recruiting patients. This study will provide evidence that LDRT is a new treatment strategy for AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Estudos Prospectivos , Resultado do Tratamento , Peptídeos beta-Amiloides/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto , Ensaios Clínicos Fase II como Assunto
3.
BMJ Open ; 13(2): e069691, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36764712

RESUMO

INTRODUCTION: Low-dose radiation therapy (LDRT) for osteoarthritis (OA) has been performed for several decades. However, supporting evidence from randomised studies using modern methodologies is lacking, and a recently published randomised study failed to show the significant benefit of LDRT. The presented trial aims to evaluate the efficacy and safety of LDRT for patients with knee OA. METHODS AND ANALYSIS: This prospective, multicentre, randomised trial will be conducted in the Republic of Korea. A total of 114 participants will be randomly assigned (1:1:1) to receive sham irradiation, 0.3 Gy/6 fractions of LDRT or 3 Gy/6 fractions of LDRT. Key inclusion criteria are primary knee OA with Kellgren-Lawrence grade 2-3 and visual analogue scale 50-90 when walking at the baseline. The primary endpoint is the rate of responders at 4 months after LDRT according to the OARSI-OMERACT criteria. Concomitant use of analgesics is prohibited until the primary efficacy evaluation is scheduled. ETHICS AND DISSEMINATION: Currently, approval from the Ministry of Food and Drug Safety of the Republic of Korea and the institutional review board of each participating hospital has been obtained. Patient enrolment began in October 2022 and is ongoing at three participating sites. The results will be disseminated to academic audiences and the public via publication in an international peer-reviewed journal and presentation at conferences. This trial will provide valuable information on the safety and efficacy of LDRT for patients with knee OA. TRIAL REGISTRATION NUMBER: NCT05562271.


Assuntos
Osteoartrite do Joelho , Humanos , Osteoartrite do Joelho/radioterapia , Estudos Prospectivos , Resultado do Tratamento , Articulação do Joelho , Medição da Dor/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
4.
Cancers (Basel) ; 14(2)2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35053535

RESUMO

Our previous work demonstrated that (E)-N-benzyl-6-(2-(3, 4-dihydroxybenzylidene) hydrazinyl)-N-methylpyridine-3-sulfonamide (BHMPS), a novel synthetic inhibitor of Rab27aSlp(s) interaction, suppresses tumor cell invasion and metastasis. Here, we aimed to further investigate the mechanisms of action and biological significance of BHMPS. BHMPS decreased the expression of epithelial-mesenchymal transition transcription factors through inhibition of focal adhesion kinase and c-Jun N-terminal kinase activation, thereby reducing the migration and invasion of breast cancer. Additionally, knockdown of Rab27a inhibited tumor migration, with changes in related signaling molecules, whereas overexpression of Rab27a reversed this phenomenon. BHMPS effectively prevented the interaction of Rab27a and its effector Slp4, which was verified by co-localization, immunoprecipitation, and in situ proximity ligation assays. BHMPS decreased the secretion of epidermal growth factor receptor and fibronectin by interfering with vesicle trafficking, as indicated by increased perinuclear accumulation of CD63-positive vesicles. Moreover, administration of BHMPS suppressed tumor growth in Rab27a-overexpressing MDA-MB-231 xenograft mice. These findings suggest that BHMPS may be a promising candidate for attenuating tumor migration and invasion by blocking Rab27a-mediated exocytosis.

5.
PLoS One ; 16(6): e0249291, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34077422

RESUMO

Naturally-derived proteins or peptides are promising biopolymers for tissue engineering applications owing to their health-promoting activity. Herein, we extracted proteins (~90%) from two-spotted cricket (Gryllus bimaculatus) and evaluated their osteoinductive potential in human bone marrow-derived mesenchymal stem cells (hBMSCs) under in vitro conditions. The extracted protein isolate was analyzed for the amino acid composition and the mass distribution of the constituent peptide fraction. Fourier transform infrared (FTIR) spectroscopy was used to determine the presence of biologically significant functional groups. The cricket protein isolate (CPI) exhibited characteristic protein peaks in the FTIR spectrum. Notably, an enhanced cell viability was observed in the presence of the extracted proteins, showing their biocompatibility. The CPI also exhibited antioxidant properties in a concentration-dependent manner. More significant mineralization was observed in the CPI-treated cells than in the control, suggesting their osteoinductive potential. The upregulation of the osteogenic marker genes (Runx2, ALP, OCN, and BSP) in CPI treated media compared with the control supports their osteoinductive nature. Therefore, cricket-derived protein isolates could be used as functional protein isolate for tissue engineering applications, especially for bone regeneration.


Assuntos
Antioxidantes/metabolismo , Diferenciação Celular , Proteínas de Insetos/administração & dosagem , Células-Tronco Mesenquimais/citologia , Osteogênese , Extratos de Tecidos/farmacologia , Animais , Células Cultivadas , Gryllidae , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Engenharia Tecidual
6.
Molecules ; 26(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806285

RESUMO

Mushrooms with enhanced medicinal properties focus on finding such compounds that could modulate the human body's immune systems. Mushrooms have antimicrobial, antidiabetic, antiviral, hepatoprotective, antitumor, and immunomodulatory properties due to the presence of various bioactive components. ß-glucans are the major constituent of the mushroom cell wall and play a significant role in their biological activity. This review described the techniques used in the extraction of the active ingredients from the mushroom. We highlighted the structure of the bioactive polysaccharides present in the mushrooms. Therapeutic applications of different mushrooms were also described. It is interesting to note that mushrooms have the potential sources of many bioactive products that can regulate immunity. Thus, the development of functional medicinal food based on the mushroom is vital for human welfare.


Assuntos
Agaricales/química , Antineoplásicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Imunoterapia/métodos , Animais , Humanos
7.
Molecules ; 25(24)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371481

RESUMO

The osteogenic differentiation of stem cells is profoundly affected by their microenvironmental conditions. The differentiation behavior of stem cells can be tuned by changing the niche environments. The proteins or peptides that are derived by living organisms facilitate the osteogenic differentiation of stem cells. Here, we have evaluated the osteoinductive and antioxidative potential of the Protaetia brevitarsis seulensis insect-derived protein for human bone marrow-derived mesenchymal stem cells (hBMSCs). The amino acid contents in the isolated protein were determined by an amino acid analyzer. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to analyze the extract's functional groups and surface morphology. The extracted protein exhibited 51.08% ß-sheet conformation. No adverse effects were observed in extract-treated cells, indicating their biocompatibility. The protein isolate showed an excellent antioxidative property. Besides this, an enhancement in the hBMSCs' mineralization has been observed in the presence of treated protein isolates. Notably, osteogenic marker genes and proteins were effectively expressed in the treated cells. These results indicated that the P. brevitarsis-derived protein isolate can be used as a potential antioxidative biomaterial for bone tissue engineering applications.


Assuntos
Antioxidantes/metabolismo , Besouros/metabolismo , Proteínas de Insetos/metabolismo , Aminoácidos/metabolismo , Animais , Osso e Ossos/metabolismo , Osso e Ossos/fisiologia , Diferenciação Celular/fisiologia , Linhagem Celular , Humanos , Larva/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , Microscopia Eletrônica de Varredura/métodos , Osteogênese/fisiologia , Peptídeos/metabolismo , Conformação Proteica em Folha beta/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Engenharia Tecidual/métodos
8.
Sci Rep ; 9(1): 16079, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31695078

RESUMO

The prevalence of allergies has increased over the last four decades. In allergic reactions, mast cells induce a hypersensitive immune response to a substance that is normally harmless. Ionizing radiation has different biological effects depending on the dose and dose rate. In this study, we investigated whether low-dose irradiation before (preventative effect) or after (therapeutic effect) an antigen-antibody reaction has an anti-allergic effect. To test this, we activated rat basophilic leukemia (RBL-2H3) mast cells with anti-2,4-dinitrophenyl IgE (antibody) and 2,4-dinitrophenyl human serum albumin, which served as an antigen. To test for both the potential of a preventative effect and a therapeutic effect, we irradiated mast cells both before and after mast cell activation, and we measured mediator release and signaling pathway activity. Low-dose ionizing radiation suppressed mediator release from RBL-2H3 mast cells activated by the antigen-antibody reaction regardless of when the mast cells were irradiated. These results were due to the suppression of FcεRI expression. Therefore, we suggest that low-dose ionizing radiation has a preventative and therapeutic effect in allergic reactions via the FcεRI-mediated RBL-2H3 mast cell activation system.


Assuntos
Hipersensibilidade/radioterapia , Leucemia Basofílica Aguda/radioterapia , Mastócitos/efeitos da radiação , Animais , Linhagem Celular , Humanos , Hipersensibilidade/imunologia , Imunoglobulina E/imunologia , Leucemia Basofílica Aguda/imunologia , Mastócitos/imunologia , Radiação Ionizante , Ratos
10.
J Immunotoxicol ; 15(1): 137-146, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30686136

RESUMO

Immune cells are known as the most sensitive tissue for ionizing radiation. Numerous reports relating with the effect of low-dose ionizing radiation (LDIR) on immune activities showed that LDIR can induce immune-potentiation via modulating the activity of B-, T-, and NK cells, or macrophages, whereas high-dose radiation induces genome-wide apoptotic/necrotic tissue injury and immune suppression. Generally, CD4+ T-cells play pivotal roles in immune systems via cytokines and cell-surface molecules to activate other types of immune cells to eliminate the pathogen. In spite of the significance of CD4+ T-cells in the immune system, mechanism of how LDIR regulates CD4+ T-cell gene expression is poorly investigated. Thus, RNA-Seq and Gene-Set Enrichment Analysis (GSEA) analysis were done with low-dose irradiated (γ-radiation, 50 mGy, 204 mGy/h)/anti-CD3/CD28-stimulated CD4+ T-cells to explore the LDIR-specific regulation of CD4+ T-cell gene expression. The results indicated that the genes related to mRNA translation processes, mitochondrial function, cell cycle regulation, and cytokine induction were upregulated in irradiated cells. Moreover, this study showed that the expression of T-helper cell Type 1 (TH1) or type 2 (TH2) cytokine genes, such as those for interferon (IFN)-γ, interleukin (IL)-4, and IL-5 were increased by at least 1.4-fold in acute (204 mGy/h) or chronic (10 mGy/h) low-dose (10 or 50 mGy) irradiated/anti-CD3/CD28 stimulated CD4+ T-cells, whereas the T-regulatory (Treg) cell cytokine gene, transforming growth factor (TGF)-ß was decreased. Overall, these findings demonstrated that LDIR could cause an upregulation of selected immune product genes and, in turn, might modulate the activity of CD4+ T-cells undergoing activation via an impact on cytokine gene regulation.


Assuntos
Mitocôndrias/fisiologia , Radiação Ionizante , Linfócitos T Reguladores/fisiologia , Células Th1/fisiologia , Células Th2/fisiologia , Animais , Antígenos CD4/metabolismo , Ciclo Celular/genética , Células Cultivadas , Citocinas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos da radiação , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Biossíntese de Proteínas/genética , Análise de Sequência de RNA , Linfócitos T Reguladores/efeitos da radiação , Células Th1/efeitos da radiação , Células Th2/efeitos dos fármacos
11.
Proc Natl Acad Sci U S A ; 114(43): 11500-11505, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29073078

RESUMO

WT p53 is critical for tumor suppression, whereas mutant p53 promotes tumor progression. Nerve injury-induced protein 1 (Ninj1) is a target of p53 and forms a feedback loop with p53 by repressing p53 mRNA translation. Here, we show that loss of Ninj1 increased mutant p53 expression and, subsequently, enhanced cell growth and migration in cells carrying a mutant p53. In contrast, loss of Ninj1 inhibited cell growth and migration in cells carrying a WT p53. To explore the biological significance of Ninj1, we generated a cohort of Ninj1-deficient mice and found that Ninj1+/- mice were prone to systemic inflammation and insulitis, but not to spontaneous tumors. We also found that loss of Ninj1 altered the tumor susceptibility in both mutant p53 and p53-null background. Specifically, in a mutant p53(R270H) background, Ninj1 deficiency shortened the lifespan, altered the tumor spectrum, and increased tumor burden, likely via enhanced expression of mutant p53. In a p53-null background, Ninj1 deficiency significantly increased the incidence of T-lymphoblastic lymphoma. Taken together, our data suggest that depending on p53 genetic status, Ninj1 has two opposing functions in tumorigenesis and that the Ninj1-p53 loop may be targeted to manage inflammatory diseases and cancer.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Inflamação/genética , Fatores de Crescimento Neural/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Alelos , Animais , Moléculas de Adesão Celular Neuronais/genética , Linhagem Celular Tumoral , Heterozigoto , Humanos , Inflamação/patologia , Longevidade , Camundongos , Camundongos Transgênicos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Fatores de Crescimento Neural/genética , Proteína Supressora de Tumor p53/genética
12.
Int J Oncol ; 51(5): 1583-1589, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29048635

RESUMO

Focal adhesion kinase 1 (FAK1) is known to promote tumor progression and metastasis by controlling cell movement, invasion, survival and the epithelial-to-mesenchymal transition in the tumor microenvironment. As recent reports imply that FAK1 is highly associated with tumor cell development and malignancy, the inhibition of FAK1 activity could be an effective therapeutic approach for inhibiting the growth and metastasis of tumor cells. In this study, we aimed to determine the effect of a novel synthetic FAK1 inhibitor 2-[2-(2-methoxy-4-morpholin-4-yl-phenylamino)-5-trifluoromethyl-pyrimidin-4-ylamino]-N-methyl-benzamide, (MPAP) on lung cancer cells. MPAP suppressed cancer cell proliferation and the phosphorylation of FAK1. Combined treatment with MPAP and irradiation (IR) showed enhanced suppression of cancer cell proliferation in wild-type p53 cells and more intense suppression in p53-null cells. In addition, the combination treatment effectively induced G1 cell cycle arrest in a p53-independent manner. In an in vivo tumor xenograft mouse model, treatment with both MPAP and IR reduced tumor growth more than the treatment with IR or MPAP alone. Overall, these data demonstrate that the radiosensitizing effect of MPAP is mediated by the regulation of retinoblastoma protein (RB) phosphorylation in a p53-independent manner.


Assuntos
Quinase 1 de Adesão Focal/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Tolerância a Radiação/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Benzamidas/administração & dosagem , Benzamidas/síntese química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos da radiação , Quinase 1 de Adesão Focal/genética , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Radiação , Tolerância a Radiação/genética , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos da radiação , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Sci Rep ; 6: 31582, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27526869

RESUMO

Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes.


Assuntos
Aminoácidos/química , Metano/química , Gás Natural , Água/química , Cristalografia por Raios X , Hidrogênio/química , Cinética , Estrutura Molecular , Termodinâmica
14.
Int J Radiat Oncol Biol Phys ; 94(5): 1207-18, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27026320

RESUMO

PURPOSE: To determine how low-dose ionizing radiation (LDIR) regulates B lympho-proliferation and its molecular mechanism related with Ikaros, transcription factor. METHODS AND MATERIALS: Splenocytes and IM-9 cells were uniformly irradiated with various doses of a (137)Cs γ-source, and cell proliferation was analyzed. To determine the LDIR-specific phosphorylation of Ikaros, immunoprecipitation and Western blot analysis were performed. To investigate the physiologic function of LDIR-mediatied Ikaros phosphorylation, Ikaros mutants at phosphorylation sites were generated, and cell cycle analysis was performed. RESULTS: First, we found that LDIR enhances B lymphoblast proliferation in an Ikaros-dependent manner. Moreover, we found that LDIR elevates the phosphorylation level of Ikaros protein. Interestingly, we showed that CK2 and AKT are involved in LDIR-induced Ikaros phosphorylation and capable of regulating DNA binding activity of Ikaros via specific phosphorylation. Finally, we identified LDIR-specific Ikaros phosphorylation sites at S391/S393 and showed that the Ikaros phosphorylations at these sites control Ikaros's ability to regulate G1/S cell cycle progression. CONCLUSION: Low-dose ionizing radiation specifically phosphorylates Ikaros protein at Ser 391/393 residues to regulate cell cycle progression in B lymphoblast.


Assuntos
Linfócitos B/efeitos da radiação , Caseína Quinase II/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/fisiologia , Fator de Transcrição Ikaros/metabolismo , Proteínas Proto-Oncogênicas c-akt/fisiologia , Pontos de Checagem da Fase S do Ciclo Celular/fisiologia , Linfócitos B/citologia , Linfócitos B/fisiologia , Linhagem Celular , Proliferação de Células/efeitos da radiação , DNA/metabolismo , Humanos , Fator de Transcrição Ikaros/genética , Mutação , Fosforilação/genética , Fosforilação/efeitos da radiação , Doses de Radiação , Radiação Ionizante
15.
J Radiat Res ; 56(2): 287-93, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25666188

RESUMO

The RNA-binding protein Sam68, a mitotic substrate of tyrosine kinases, has been reported to participate in the cell cycle, apoptosis, and signaling. In particular, overexpression of Sam68 protein is known to suppress cell growth and cell cycle progression in NIH3T3 cells. Although Sam68 is involved in many cellular activities, the function of Sam68, especially in response to apoptotic stimulation, is not well understood. In this study, we found that Sam68 protein is cleaved in immune cells undergoing apoptosis induced by γ-radiation. Moreover, we found that Sam68 cleavage was induced by apoptotic stimuli containing γ-radiation in a caspase-dependent manner. In particular, we showed that activated casepase-3, 7, 8 and 9 can directly cleave Sam68 protein through in vitro protease cleavage assay. Finally, we found that the knockdown of Sam68 attenuated γ-radiation-induced cell death and growth suppression. Conclusively, the cleavage of Sam68 is a new indicator for the cell damaging effects of ionizing radiation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/fisiologia , Caspases/metabolismo , Proliferação de Células/fisiologia , Proteínas de Ligação a DNA/metabolismo , Raios gama , Proteínas de Ligação a RNA/metabolismo , Apoptose/efeitos da radiação , Biomarcadores/metabolismo , Linhagem Celular , Proliferação de Células/efeitos da radiação , Relação Dose-Resposta à Radiação , Ativação Enzimática/fisiologia , Ativação Enzimática/efeitos da radiação , Humanos , Células Jurkat , Doses de Radiação
16.
Oncotarget ; 6(1): 305-16, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25622105

RESUMO

Hypoxia-inducible factor 1 (HIF1), a heterodimeric transcription factor, consists of HIF1α and HIF1ß and is necessary for cell growth and survival under a hypoxic condition. Thus, the level and activity of HIF1α needs to be tightly controlled. Indeed, HIF1α protein stability is controlled by prolyl hydroxylase and von Hippel-Lindau-mediated proteosomal degradation. However, it remains unclear whether HIF1α expression is controlled by other pathways. Here, we showed that RNA-binding protein RBM38, a target of the p53 family, regulates HIF1α expression via mRNA translation. Specifically, we showed that under a hypoxic condition, ectopic expression of RBM38 decreased, whereas knockdown of RBM38 increased, the level of HIF1α protein. We also showed that the rate of de novo HIF1α protein synthesis was increased by knockdown of RBM38. Additionally, we showed that RBM38 directly bound to HIF1α 5' and 3'UTRs. Consistently, we showed that the rate of mRNA translation for a heterologous reporter that carries HIF1α 5'and/or 3'UTRs was increased upon knockdown of RBM38. Furthermore, we showed that knockdown of RBM38 increased, whereas ectopic expression of RBM38 decreased, the binding of eIF4E to HIF1α mRNA. Together, our data suggest that RBM38 is a novel translational regulator of HIF1α under a hypoxic condition.


Assuntos
Regulação da Expressão Gênica/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Biossíntese de Proteínas/fisiologia , Proteínas de Ligação a RNA/metabolismo , Western Blotting , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , Imunoprecipitação , Interferência de RNA , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Biochem J ; 464(3): 377-86, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25268038

RESUMO

POLH (DNA polymerase η), a target of p53 tumour suppressor, plays a key role in TLS (translesion DNA synthesis). Loss of POLH is responsible for the human cancer-prone syndrome XPV (xeroderma pigmentosum variant). Owing to its critical role in DNA repair and genome stability, POLH expression and activity are regulated by multiple pathways. In the present study, we found that the levels of both POLH transcript and protein were decreased upon knockdown of the transcript encoding PCBP1 [poly(rC)-binding protein 1]. We also found that the half-life of POLH mRNA was markedly decreased upon knockdown of PCBP1. Moreover, we found that PCBP1 directly bound to the POLH 3'-UTR and the PCBP1-binding site in POLH mRNA is an atypical AU-rich element. Finally, we showed that the AU-rich element in POLH 3'-UTR was responsive to PCBP1 and sufficient for PCBP1 to regulate POLH expression. Taken together, we uncovered a novel mechanism by which POLH expression is controlled by PCBP1 via mRNA stability.


Assuntos
DNA Polimerase Dirigida por DNA/genética , Ribonucleoproteínas Nucleares Heterogêneas/fisiologia , Estabilidade de RNA/genética , Regiões 3' não Traduzidas , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , DNA Polimerase Dirigida por DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HCT116 , Células HEK293 , Humanos , Células MCF-7 , Ligação Proteica , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA
18.
Mol Cancer Res ; 12(3): 359-69, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24375645

RESUMO

UNLABELLED: p63, a p53 family member, plays pivotal roles in epidermal development, aging, and tumorigenesis. Thus, understanding how p63 expression is controlled has biological and clinical importance. RBM24 is an RNA-binding protein and shares a high sequence similarity with RBM38, a critical regulator of p63. In this study, we investigated whether RBM24 is capable of regulating p63 expression. Indeed, we found that ectopic expression of RBM24 decreased, whereas knockdown of RBM24 increased, the levels of p63 transcript and protein. To explore the underlying mechanism, we found that RBM24 was able to bind to multiple regions in the p63 3' untranslated region and, subsequently, destabilize p63 transcript. Furthermore, we showed that the 3' untranslated region in p63 transcript and the RNA-binding domain in RBM24 were required for RBM24 to bind p63 transcript and consequently, inhibit p63 expression. Taken together, our data provide evidence that RBM24 is a novel regulator of p63 via mRNA stability. IMPLICATIONS: Our study suggests that p63 is regulated by RBM24 via mRNA stability, which gives an insight into understanding how posttranscriptional regulatory mechanisms contribute to p63 expression.


Assuntos
Estabilidade de RNA , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/biossíntese , Proteínas Supressoras de Tumor/biossíntese , Regiões 3' não Traduzidas , Sequência de Aminoácidos , Animais , Diferenciação Celular/fisiologia , Expressão Gênica , Técnicas de Silenciamento de Genes , Células HCT116 , Humanos , Células MCF-7 , Camundongos , Dados de Sequência Molecular , Plasmídeos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética
19.
Genes Dev ; 27(20): 2246-58, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24142875

RESUMO

The RNPC1 RNA-binding protein, also called Rbm38, is a target of p53 and a repressor of p53 mRNA translation. Thus, the p53-RNPC1 loop is critical for modulating p53 tumor suppression, but it is not clear how the loop is regulated. Here, we showed that RNPC1 is phosphorylated at Ser195 by glycogen synthase kinase 3 (GSK3). We also showed that GSK3 promotes p53 mRNA translation through phosphorylation of RNPC1. Interestingly, we found that the phosphor-mimetic mutant S195D and the deletion mutant Δ189-204, which lacks the GSK3 phosphorylation site, are unable to repress p53 mRNA translation due to loss of interaction with eukaryotic translation factor eIF4E on p53 mRNA. Additionally, we found that phosphorylated RNPC1, RNPC1-S195D, and RNPC1(Δ189-204) promote p53 mRNA translation through interaction with eukaryotic translation factor eIF4G, which then facilitates the assembly of the eIF4F complex on p53 mRNA. Furthermore, we showed that upon inhibition of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway, GSK3 is activated, leading to increased RNPC1 phosphorylation and increased p53 expression in a RNPC1-dependent manner. Together, we postulate that the p53-RNPC1 loop can be explored to increase or decrease p53 activity for cancer therapy.


Assuntos
Regulação Neoplásica da Expressão Gênica , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/genética , Regiões 3' não Traduzidas/genética , Linhagem Celular Tumoral , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Células HCT116 , Humanos , Células MCF-7 , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo
20.
PLoS One ; 8(8): e71724, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23940783

RESUMO

p63, a transcription factor and p53 family protein, plays a crucial role in tumor suppression and development of various epithelial tissues. While p63 expression is controlled mostly by post-translational modifications, recent studies indicate that transcriptional and posttranscriptional regulations are essential for proper p63 expression. Here, we investigated the regulation of p63 expression by poly (C)-binding protein 1 (PCBP1, also known as hnRNP-E1 and αCP1). We found that knockdown of PCBP1 decreases the level of p63 transcript and protein. We also found that PCBP1 regulates the stability of p63 mRNA via binding to p63 3'UTR. Additionally, we found that a CU-rich element (CUE) in p63 3'UTR is bound by and responsive to PCBP1. Together, we conclude that PCBP1 regulates p63 expression via mRNA stability.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas/fisiologia , RNA Mensageiro/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Regiões 3' não Traduzidas , Sequência de Bases , Proteínas de Ligação a DNA , Regulação da Expressão Gênica , Humanos , Células MCF-7 , Ligação Proteica , Estabilidade de RNA , RNA Mensageiro/genética , Proteínas de Ligação a RNA , Sequências Reguladoras de Ácido Ribonucleico , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética
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