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1.
Data Brief ; 42: 108197, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35515992

RESUMO

We performed RNA-seq analyses of mRNA isolated from five organs, liver, bone, heart, kidney and blood at the pre-symptomatic state of klotho mice with/without administration of a Japanese traditional herbal medicine, juzentaihoto (JTT). Data of differentially expressed genes (DEG) with/without JTT was included. Intron retention (IR) is an important regulatory mechanism that affects gene expression and protein functions. We collected data in which retained-introns were accumulated in a particular set of genes of these organs, and showed that among these retained introns in the liver and bone a subset was recovered to the normal state by the medicine. All of the data present changes of molecular events on the levels of metabolites, proteins and gene expressions observed at the pre- symptomatic state of aging in klotho mice with/without JTT. The research article related to this Data in Brief is published in GENE entitled as "Intron retention as a new pre-symptomatic marker of aging and its recovery to the normal state by a traditional Japanese herbal medicine".

2.
Gene ; 794: 145752, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34082065

RESUMO

Intron retention (IR) is an important regulatory mechanism that affects gene expression and protein functions. Using klotho mice at the pre-symptomatic state, we discovered that retained-introns accumulated in several organs including the liver and that among these retained introns in the liver a subset was recovered to the normal state by a Japanese traditional herbal medicine. This is the first report of IR recovery by a medicine. IR-recovered genes fell into two categories: those involved in liver-specific metabolism and in splicing. Metabolome analysis of the liver showed that the klotho mice were under starvation stress. In addition, our differentially expressed gene analysis showed that liver metabolism was actually recovered by the herbal medicine at the transcriptional level. By analogy with the widespread accumulation of intron-retained pre-mRNAs induced by heat shock stress, we propose a model in which retained-introns in klotho mice were induced by an aging stress and in which this medicine-related IR recovery is indicative of the actual recovery of liver-specific metabolic function to the healthy state. Accumulation of retained-introns was also observed at the pre-symptomatic state of aging in wild-type mice and may be an excellent marker for this state in general.


Assuntos
Envelhecimento/genética , Perfilação da Expressão Gênica/métodos , Marcadores Genéticos/efeitos dos fármacos , Glucuronidase/genética , Fígado/química , Compostos Fitoquímicos/administração & dosagem , Envelhecimento/efeitos dos fármacos , Processamento Alternativo , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Resposta ao Choque Térmico , Íntrons , Japão , Proteínas Klotho , Fígado/efeitos dos fármacos , Medicina Tradicional , Metabolômica , Camundongos , Modelos Animais , Compostos Fitoquímicos/farmacologia , Precursores de RNA/genética , Análise de Sequência de RNA
3.
Biochem Biophys Res Commun ; 508(2): 410-415, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30502085

RESUMO

During the maturation of transfer RNA (tRNA), a variety of chemical modifications can be introduced at specific nucleotide positions post-transcriptionally. 5-Methyluridine (m5U) is one of the most common and conserved modifications from eubacteria to eukaryotes. Although TrmA protein in Escherichia coli and Trm2p protein in Saccharomyces cerevisiae, which are responsible for the 5-methylation of uracil at position 54 (m5U54) on tRNA, are well characterized, the biological function of the U54 methylation responsible enzyme in mammalian species remains largely unexplored. Here, we show that the mammalian tRNA methyltransferase 2 homolog A (TRMT2A) protein harbors an RNA recognition motif in the N-terminus and the conserved uracil-C5-methyltransferase domain of the TrmA family in the C-terminus. TRMT2A predominantly localizes to the nucleus in HeLa cells. TRMT2A-overexpressing cells display decreased cell proliferation and altered DNA content, while TRMT2A-deficient cells exhibit increased growth. Thus, our results reveal the inhibitory role of TRMT2A on cell proliferation and cell cycle control, providing evidence that TRMT2A is a candidate cell cycle regulator in mammals.


Assuntos
Ciclo Celular/fisiologia , Proliferação de Células/fisiologia , tRNA Metiltransferases/metabolismo , Sequência de Aminoácidos , Animais , Domínio Catalítico , Ciclo Celular/genética , Proliferação de Células/genética , Células Cultivadas , Sequência Conservada , Desoxirribonucleases/genética , Proteínas de Escherichia coli/genética , Fibroblastos/citologia , Fibroblastos/enzimologia , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Filogenia , Domínios Proteicos , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , tRNA Metiltransferases/química , tRNA Metiltransferases/genética
4.
J Biol Chem ; 289(31): 21663-72, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24928506

RESUMO

Translesion (TLS) DNA polymerases are specialized, error-prone enzymes that synthesize DNA across bulky, replication-stalling DNA adducts. In so doing, they facilitate the progression of DNA synthesis and promote cell proliferation. To potentiate the effect of cancer chemotherapeutic regimens, we sought to identify inhibitors of TLS DNA polymerases. We screened five libraries of ∼ 3000 small molecules, including one comprising ∼ 600 nucleoside analogs, for their effect on primer extension activity of DNA polymerase η (Pol η). We serendipitously identified sphingosine, a lipid-signaling molecule that robustly stimulates the activity of Pol η by ∼ 100-fold at low micromolar concentrations but inhibits it at higher concentrations. This effect is specific to the Y-family DNA polymerases, Pols η, κ, and ι. The addition of a single phosphate group on sphingosine completely abrogates this effect. Likewise, the inclusion of other sphingolipids, including ceramide and sphingomyelin to extension reactions does not elicit this response. Sphingosine increases the rate of correct and incorrect nucleotide incorporation while having no effect on polymerase processivity. Endogenous Pol η activity is modulated similarly as the recombinant enzyme. Importantly, sphingosine-treated cells exhibit increased lesion bypass activity, and sphingosine tethered to membrane lipids mimics the effects of free sphingosine. Our studies have uncovered sphingosine as a modulator of TLS DNA polymerase activity; this property of sphingosine may be associated with its known role as a signaling molecule in regulating cell proliferation in response to cellular stress.


Assuntos
Dano ao DNA , DNA Polimerase Dirigida por DNA/metabolismo , Esfingosina/fisiologia , Sequência de Bases , Primers do DNA , Células HEK293 , Humanos , Lipossomos
5.
Nucleic Acids Res ; 41(4): 2621-31, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23295668

RESUMO

Deciphering the genetic code is a fundamental process in all living organisms. In many bacteria, AUA codons are deciphered by tRNA(Ile2) bearing lysidine (L) at the wobble position. L is a modified cytidine introduced post-transcriptionally by tRNA(Ile)-lysidine synthetase (TilS). Some bacteria, including Mycoplasma mobile, do not carry the tilS gene, indicating that they have established a different system to decode AUA codons. In this study, tRNA(Ile2) has been isolated from M. mobile and was found to contain a UAU anticodon without any modification. Mycoplasma mobile isoleucyl-tRNA synthetase (IleRS) recognized the UAU anticodon, whereas Escherichia coli IleRS did not efficiently aminoacylate tRNA(Ile2)(UAU). In M. mobile IleRS, a single Arg residue at position 865 was critical for specificity for the UAU anticodon and, when the corresponding site (W905) in E. coli IleRS was substituted with Arg, the W905R mutant efficiently aminoacylated tRNA with UAU anticodon. Mycoplasma mobile tRNA(Ile2) cannot distinguish between AUA and AUG codon on E. coli ribosome. However, on M. mobile ribosome, M. mobile tRNA(Ile2)(UAU) specifically recognized AUA codon, and not AUG codon, suggesting M. mobile ribosome has a property that prevents misreading of AUG codon. These findings provide an insight into the evolutionary reorganization of the AUA decoding system.


Assuntos
Anticódon/química , Códon/química , Isoleucina-tRNA Ligase/química , Mycoplasma/genética , RNA de Transferência de Isoleucina/química , Sequência de Aminoácidos , Arginina/química , Isoleucina-tRNA Ligase/metabolismo , Cinética , Dados de Sequência Molecular , Mycoplasma/enzimologia , RNA de Transferência de Isoleucina/isolamento & purificação , RNA de Transferência de Isoleucina/metabolismo , Ribossomos/metabolismo , Alinhamento de Sequência
6.
J Biochem ; 152(6): 539-48, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23024156

RESUMO

Aminoacyl-tRNA synthetases play a key role in the translation of genetic code into correct protein sequences. These enzymes recognize cognate amino acids and tRNAs from noncognate counterparts, and catalyze the formation of aminoacyl-tRNAs. While Although several tyrosyl-tRNA synthetases (TyrRSs) from various species have been structurally and functionally well characterized, the crenarchaeal TyrRS remains poorly understood. In this study, we performed mutational analyses on tyrosine tRNA (tRNA(Tyr)) and TyrRS from the crenarchaeon, Aeropyrum pernix, to investigate the molecular recognition mechanism. Kinetics for tyrosylation using in vitro transcript indicated that the discriminator base A73 and adjacent G72 in the acceptor stem are identity elements of tRNA(Tyr), whereas the C1 base and anticodon had modest roles as identity determinants. Intriguingly, in contrast to the identity element of eukaryotic/euryarchaeal TyrRSs, the first base-pair (C1-G72) of the acceptor stem was not essential in crenarchaeal TyrRS as a pair. Furthermore, A. pernix TyrRS mutants were constructed at positions Tyr39 and Asp172, which could form hydrogen bonds with the 4-hydroxyl group of l-tyrosine. The tyrosylation activities with the mutants resulted that Asp172 mutants completely abolished tyrosylation activity, whereas Tyr39 mutants had no effect on activity. Thus, crenarchaeal TyrRS appears to adopt different molecular recognition mechanism from other TyrRSs.


Assuntos
Aeropyrum/enzimologia , Proteínas Arqueais/genética , RNA de Transferência de Tirosina/genética , Tirosina-tRNA Ligase/genética , Aeropyrum/genética , Substituição de Aminoácidos , Proteínas Arqueais/química , Sequência de Bases , Cinética , Mutagênese Sítio-Dirigida , RNA Arqueal/química , RNA Arqueal/genética , RNA de Cadeia Dupla/genética , RNA de Transferência de Tirosina/química , Especificidade por Substrato , Transcrição Gênica , Tirosina/química , Tirosina-tRNA Ligase/química
8.
Rinsho Ketsueki ; 52(3): 136-41, 2011 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-21471701

RESUMO

We present two long-term survivors after allogeneic transplantation with reduced-intensity conditioning regimen following relapse after autologous stem cell transplantation (ASCT) for multiple myeloma (MM). The first case was a 47-year-old male with IgG MM treated with 2 courses of high-dose melphalan along with ASCT and thalidomide, resulting in a minimal response. He then received 2 courses of bortezomib plus dexamethasone (BD) regimen, which was discontinued due to peripheral neuropathy. Allogeneic peripheral stem cell transplantation (PBSCT) from a sibling donor was performed after pretreatment with fludarabin (125 mg/m(2)) and melphalan (100 mg/m(2)). Engraftment was observed on day 11 and monoclonal IgG had disappeared 5 months after transplantation. The patient has been in complete remission for more than two and a half years with moderate chronic graft-versus-host disease (GVHD). The second case was a 51-year-old male who relapsed after ASCT for IgA MM. After 3 courses of BD treatment, irradiation to lumbar plasmacytoma, and thalidomide therapy, he received allogeneic PBSCT from a related donor after the same reduced intensity conditioning as performed in case 1. A complete response was observed 6 months after PBSCT. The patient has remained relapse-free for two years without GVHD. BD treatment followed by allogeneic stem cell transplantation with reduced intensity conditioning is supposed to be one of the most powerful strategies for patients showing relapse after ASCT.


Assuntos
Antineoplásicos/uso terapêutico , Ácidos Borônicos/uso terapêutico , Dexametasona/uso terapêutico , Mieloma Múltiplo/terapia , Pirazinas/uso terapêutico , Transplante de Células-Tronco , Condicionamento Pré-Transplante , Antineoplásicos/administração & dosagem , Bortezomib , Terapia Combinada , Progressão da Doença , Quimioterapia Combinada , Efeito Enxerto vs Tumor , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Autólogo , Transplante Homólogo , Resultado do Tratamento
9.
Cancer Res ; 70(11): 4269-73, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20460534

RESUMO

The 40th International Symposium of the Princess Takamatsu Cancer Research Fund, entitled "DNA Repair and Human Cancers," was held on November 10-12, 2009 at Hotel Grand Palace, Tokyo, Japan. The meeting focused on the role of DNA repair in preventing mutations by endogenous and exogenous DNA damage and increasing the efficacy of chemotherapeutic agents by interfering with DNA repair. The 14 presentations by the speakers from the United States, four from the United Kingdom, one each from Italy, The Netherlands, and France, and 13 from Japan, covered most aspects of DNA repair, spanning DNA damage, molecular structures of repair enzymes, and clinical studies on inhibition of DNA repair processes. Extensive time was reserved for discussions with the active participation of the 150 invited Japanese scientists. The choice of a symposium on DNA repair in human cancers resulted in part from the excellent basic and clinical studies that have been carried out for many years in Japan, and the general lack of recognition versus the importance of DNA repair in understanding carcinogenesis.


Assuntos
Reparo do DNA , Neoplasias/genética , Animais , Dano ao DNA , Humanos , Mutação
10.
Gan To Kagaku Ryoho ; 37(1): 169-71, 2010 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-20087056

RESUMO

In May 2007, a 48-year-old woman was admitted to our hospital for acute intestinal obstruction, and she was subsequently diagnosed with metastatic colorectal cancer in the sigmoid colon. Jejunum-ileum anastomosis and colostomy were performed as palliative surgery because the locally-advanced primary tumor had involved the ileum and other surrounding organs and formed huge mass. After placement of a central venous port, palliative chemotherapy mFOLFOX6 was commenced. In May 2008, mFOLFOX6 was replaced with FOLFIRI because of progression of both the metastasized and the primary tumors. On November 20, 2008, cetuximab was added to FOLFIRI because of the further disease progression. However, on December 24, 2008, the patient presented with sudden-onset dyspnea. Her blood gas analysis revealed severe hypoxemia and metabolic acidosis, and CT scan showed bilateral pulmonary artery embolism. After intensive treatment, the patient was able to walk under the room-air condition. However, on January 19, 2009, she died of pneumonitis. We believe that this is an interesting case with respect to the relationship between pulmonary embolism and malignancy and may hint at a causal relationship between pulmonary embolism and cetuximab, which is currently uncertain. We report this case herein along with a literature review.


Assuntos
Anticorpos Monoclonais/efeitos adversos , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Embolia Pulmonar/induzido quimicamente , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Cetuximab , Feminino , Fluoruracila/administração & dosagem , Humanos , Irinotecano , Leucovorina/administração & dosagem , Pessoa de Meia-Idade , Cuidados Paliativos
11.
Nihon Shokakibyo Gakkai Zasshi ; 106(6): 787-92, 2009 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-19498309

RESUMO

A 47-year-old woman patient who presented with weakness in the proximal parts of the upper and lower limbs and difficulty in swallowing was given a diagnosis of advanced esophageal cancer complicated with polymyositis. Steroid therapy was initiated for the polymyositis, but the CK level remained high. Chemotherapy was then selected as the preferred treatment option for the esophageal cancer, however, the treatment was ineffective and the patient died of respiratory failure. There is currently no consensus on the safety of therapy for malignant carcinoma complicated with collagen diseases, therefore, the selection of treatment modality for the disease must be made with care.


Assuntos
Neoplasias Esofágicas/complicações , Polimiosite/complicações , Autopsia , Neoplasias Esofágicas/patologia , Feminino , Humanos , Pessoa de Meia-Idade
12.
J Biol Chem ; 284(27): 18218-27, 2009 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-19414587

RESUMO

tRNA guanine transglycosylase (TGT) enzymes are responsible for the formation of queuosine in the anticodon loop (position 34) of tRNA(Asp), tRNA(Asn), tRNA(His), and tRNA(Tyr); an almost universal event in eubacterial and eukaryotic species. Despite extensive characterization of the eubacterial TGT the eukaryotic activity has remained undefined. Our search of mouse EST and cDNA data bases identified a homologue of the Escherichia coli TGT and three spliced variants of the queuine tRNA guanine transglycosylase domain containing 1 (QTRTD1) gene. QTRTD1 variant_1 (Qv1) was found to be the predominant adult form. Functional cooperativity of TGT and Qv1 was suggested by their coordinate mRNA expression in Northern blots and from their association in vivo by immunoprecipitation. Neither TGT nor Qv1 alone could complement a tgt mutation in E. coli. However, transglycosylase activity could be obtained when the proteins were combined in vitro. Confocal and immunoblot analysis suggest that TGT weakly interacts with the outer mitochondrial membrane possibly through association with Qv1, which was found to be stably associated with the organelle.


Assuntos
Processamento Alternativo/genética , Membranas Mitocondriais/enzimologia , Nucleosídeo Q/genética , Pentosiltransferases/genética , RNA de Transferência/genética , Fatores Etários , Sequência de Aminoácidos , Animais , Células COS , Catálise , Chlorocebus aethiops , Citoplasma/enzimologia , DNA Complementar , Escherichia coli , Masculino , Camundongos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Mensageiro/metabolismo , RNA de Transferência/química , Coelhos
13.
Eur J Haematol ; 80(2): 160-3, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18028432

RESUMO

In this study, we retrospectively analyzed 213 Japanese patients with chronic myeloid leukemia (CML) treated with imatinib mesylate. In 150 evaluable patients, mean daily doses were 400 mg or more in 42 patients, 300-400 mg in 42 patients, 200-300 mg in 44 patients and <200 mg in 22 patients. Complete hematologic response was observed in all the 84 patients treated with mean daily doses of 300 mg or more and complete cytogenetic response was achieved in 94.8% of those patients. In comparison with the effects of 300 mg or more, mean daily doses of 200-300 mg led to less complete cytogenetic response (78.6% vs. 94.8%, P < 0.01), shorter complete cytogenetic remission duration (81.3% vs. 95.6% at 24 months, P = 0.01), and lower overall survival (90.0% vs. 98.8% at 36 months, P = 0.03). This study suggests that the mean daily doses of 300 mg (roughly equivalent to 100,000 mg/yr) or more may improve overall survival and that mean daily doses of imatinib during the first year may be one of the prognostic factors for CML in Japan.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Esquema de Medicação , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/administração & dosagem , Piperazinas/uso terapêutico , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Criança , Feminino , Humanos , Mesilato de Imatinib , Japão , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
14.
J Biol Chem ; 283(4): 2021-30, 2008 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-18039655

RESUMO

The selenocysteine tRNA (tRNA(Sec)) molecule is the sight of synthesis for the amino acid selenocysteine and the adaptor for its translational insertion into selenoprotein enzymes, the majority of which contribute to cellular redox homeostasis. To examine the consequences of selenoprotein depletion on the oxidative environment of the cell, we generated a conditional knock-out mouse for the tRNA(Sec) gene (Trsp). Deletion of Trsp in either macrophages or liver elevated oxidative stress and activated the transcriptional induction of cytoprotective antioxidant and detoxification enzyme genes, including glutathione S-transferase P1 and NAD(P)H:quinone oxidoreductase 1, and other well known target genes of the transcription factor Nrf2 (NF-E2-related factor 2). Simultaneous disruption of Trsp and Nrf2 severely compromised the cytoprotective response. Double knock-out macrophages displayed reduced viability, elevated oxidative stress, and increased susceptible to hydrogen peroxide treatment compared with deletion of either gene alone. Mice carrying a liver-specific deletion of Trsp on an Nrf2-null background experienced hepatocellular apoptosis and displayed a severely reduced survival rate compared with loss of Trsp alone. Our results thus demonstrate that reduced selenoprotein activity is counterbalanced by an Nrf2-mediated cytoprotective response, which is essential for maintaining cellular redox homeostasis and viability.


Assuntos
Apoptose/fisiologia , Homeostase/fisiologia , Fígado/metabolismo , Macrófagos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , RNA de Transferência Aminoácido-Específico/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Feminino , Deleção de Genes , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Homeostase/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Fígado/citologia , Macrófagos/citologia , Masculino , Camundongos , Camundongos Knockout , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator 2 Relacionado a NF-E2/genética , Especificidade de Órgãos/fisiologia , Oxidantes/farmacologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , RNA de Transferência Aminoácido-Específico/genética , Selenocisteína/genética , Selenocisteína/metabolismo , Selenoproteínas/genética , Selenoproteínas/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/fisiologia
15.
Biochem Biophys Res Commun ; 364(4): 966-71, 2007 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-17971305

RESUMO

Transcription factor Nrf2 regulates production of antioxidants and protects cells from oxidative/electrophilic stresses. Paradoxically, glutathione, one of the Nrf2-regulated antioxidants, has been assumed to promote genotoxicity of KBrO3. To address this glutathione hypothesis, we examined roles Nrf2 plays in the cellular defense against KBrO3-induced oxidative damage using Nrf2-/-, Ogg1-/- and Nrf2::Ogg1 double knockout mice. We found that upon KBrO3 treatment Nrf2::Ogg1 double knockout animals suffered from severe kidney damage, but unexpectedly the double knockout mice accumulated lower level of 8-hydroxyguanine than Ogg1-/- mice. Thus, KBrO3-induced nephrotoxicity appears not to depend on the formation of 8-hydroxyguanine. Our data also indicate that both the KBrO3-induced nephrotoxicity and formation of 8-hydroxyguanine are Nrf2-controlled processes, but the changes of the glutathione level are Nrf2-independent. Based on these results we conclude that glutathione is a minor part of the mechanism promoting genotoxicity of KBrO3 in Ogg1 knockout mice.


Assuntos
Bromatos/farmacologia , Dano ao DNA/fisiologia , DNA Glicosilases/metabolismo , Rim/metabolismo , Fígado/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Dano ao DNA/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Camundongos , Camundongos Knockout , Oxirredução/efeitos dos fármacos
16.
Cancer Sci ; 98(6): 803-14, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17441966

RESUMO

Oxidative stress to DNA is recognized as a mechanism underlying carcinogenic effects of some environmental agents. Here, we hypothesized that dimethylarsinic acid (DMA(V)), an organic metabolite of inorganic arsenic in humans, might exert carcinogenic potential in a mouse line carrying a mutant Mmh allele of the Mmh/OGG1 gene encoding the enzyme 8-hydroxyguanine DNA glycosylase 1 (OGG1). Ogg1 mutant and wild type mice were treated with DMA(V) in their drinking water at a dose of 200 p.p.m. for up to 72 weeks. All DMA(V)-treated Ogg1(-/-)animals developed tumors, with a tendency for lower total incidences in the Ogg1(+/+) cases. Lung tumors in particular were induced as compared to the lack in non-carcinogen controls and were significantly more frequent in the homozygotes. At week 4, the levels of DNA 8-OH-dG and cell proliferation were significantly elevated in the lungs of non-treated Ogg1(-/-) as compared to Ogg1(+/+) mice and were strongly enhanced by DMA(V) treatment. Marked induction of Pola1, Cyp7b1, Ndfua3, Mmp13 and other genes specific to cell proliferation, cell signaling and xenobiotic metabolism in the lungs of DMA(V)-treated Ogg1(-/-) mice was found. Electron microscopic examination revealed the growth of microvilli, with increased numbers of mitochondria only in lungs and lung tumors of DMA(V)-exposed Ogg1(-/-) mice. Therefore, we strongly suggest that DMA(V) exerts carcinogenicity in the lungs of Ogg1(-/-) mutant mice, with a possible role for persistent accumulation of DNA oxidative adducts.


Assuntos
Ácido Cacodílico , DNA Glicosilases/genética , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , 8-Hidroxi-2'-Desoxiguanosina , Animais , Apoptose , Ácido Cacodílico/metabolismo , Testes de Carcinogenicidade , Proliferação de Células , Dano ao DNA , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Knockout , Mutação , Estresse Oxidativo , Taxa de Sobrevida
17.
Toxicology ; 221(2-3): 179-86, 2006 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-16494984

RESUMO

In order to assess the effect of potassium bromate (KBrO3) on the induction of tumor formation, a 1-year carcinogenesis study was performed using Ogg1 knockout mice (Ogg1(-/-)) and wild-type mice (Ogg1(+/+)). The mice were chronically exposed to KBrO3 by putting it in the drinking water for 29 weeks, at 2 g/l for the first 18 weeks, and then at 1 g/l for another 11 weeks. After termination of treatment the mice were kept for an additional 23 weeks. The amount of 8-hydroxydeoxyguanosine (8-OH-dG) in kidney DNA after 29 weeks of KBrO3 exposure reached 500 8-OH-dG/10(6) dG, almost 250-fold that of untreated wild-type mice. During the course of study the mice appeared normal, although a decrease of body weight gain in both Ogg1(-/-) and Ogg1(+/+) mice exposed to KBrO3, and some kidney malfunction in KBrO3 treated Ogg1(-/-) mice was observed. Surprisingly, when Ogg1(-/-) and Ogg1(+/+) mice were sacrificed at 52 weeks, no tumor formation could be found in kidney or other organs such as lung, liver, spleen, thymus, stomach and intestine. Microscopic examination also showed the absence of precancerous foci in all tissues of both Ogg1(-/-) and Ogg1(+/+) mice. A possible explanation is presented to reconcile these results with those of others which showed an increased incidence of tumor formation in untreated Ogg1(-/-) mice.


Assuntos
Bromatos/toxicidade , Dano ao DNA , DNA Glicosilases/genética , Guanina/análogos & derivados , Rim/efeitos dos fármacos , Neoplasias/induzido quimicamente , Administração Oral , Animais , Testes de Carcinogenicidade , Guanina/metabolismo , Rim/metabolismo , Camundongos , Camundongos Knockout , Neoplasias/genética , Neoplasias/metabolismo
19.
Proc Jpn Acad Ser B Phys Biol Sci ; 82(4): 127-41, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-25792776

RESUMO

8-Hydroxyguanine (8-OH-G) was discovered in 1983 in our laboratory at the National Cancer Center Research Institute, Tokyo. Since it could be formed in DNA not only in vitro but also in vivo by oxygen radical forming agents, we immediately hypothesized the importance of this discovery in connection with its biological consequence. Further intensive efforts by us from 1983 to 1990 confirmed that 8-OH-G is a highly significant oxidated DNA lesion involved in mutation and/or carcinogenesis in mammals, including humans. With the subsequent entry of many investigators to this research field the number of publications on 8-OH-G increased exponentially, reaching more than several thousands by the end of 2005. In this article, a summary is given of the important works carried out in the early days, and further notable contributions by many investigators are reviewed, focusing on 8-OH-G in the mammalian system. A special emphasis is given to research on knockout mice that are deficient in genes involved in the repair systems of the 8-OH-G lesion. Lastly, our own recent work is summarized involving a one-year carcinogenesis study of Ogg1 (the gene for 8-OH-G specific glycosylase/AP lyase) knockout mice that have been exposed to oxidative stress.

20.
Gan To Kagaku Ryoho ; 32(12): 1941-4, 2005 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-16282731

RESUMO

Since the advent of imatinib mesylate (IM), its clinical efficacy against gastrointestinal stromal tumor (GIST) has been widely acknowledged, and therapeutic strategies for this disease have undergone great changes. We recently experienced a case of giant GIST of the stomach that was successfully treated with IM neoadjuvant therapy prior to surgical resection, but liver metastasis recurred 1 year and 7 months after the operation. The patient was a 65-year-old male who presented at our department with the chief complaints of dizziness, malaise, and fever in April 2002. An abdominal CT revealed a mass with a maximum diameter of 17 cm, as well as a cystic septate mass, 12 cm in diameter, with a thick capsule in the left lobe of the liver. The patient was diagnosed with GIST of the stomach and liver metastasis. Since radical operation was considered difficult at that point, IM (400 mg/day) was started on May 9. The result of treatment was determined to be PR, and radical operation was considered feasible. On March 18, 2003, total gastrectomy and left hepatic lobectomy/S 6 partial lobectomy were performed in the surgery department of our hospital. The postoperative course was favorable and oral administration of IM was resumed soon after the operation. However, the drug was discontinued for financial reasons and a decreased white blood cell count (grade 3) 2 months after the operation. Recurrence in the liver and abdominal wall was found in October 2004, and oral administration of IM was resumed again. Currently, treatment with IM is ongoing. Case reports on the efficacy of IM neoadjuvant therapy are occasionally found in the literature, but there are few reports on its long-term prognosis. We report this case with a discussion of future therapeutic options.


Assuntos
Antineoplásicos/uso terapêutico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Idoso , Benzamidas , Terapia Combinada , Esquema de Medicação , Gastrectomia , Tumores do Estroma Gastrointestinal/patologia , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Mesilato de Imatinib , Masculino , Terapia Neoadjuvante , Prognóstico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia
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