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1.
Surg Case Rep ; 9(1): 69, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37133772

RESUMO

BACKGROUND: CA19-9 is strongly expressed in malignant tumors of the digestive system and is widely used as a marker for gastrointestinal cancer. In this report, we describe a case of acute cholecystitis in which CA19-9 was markedly elevated. CASE PRESENTATION: A 53-year-old man was admitted to our hospital with a diagnosis of acute cholecystitis after being referred to our hospital with a chief complaint of fever and right hypochondrial pain. CA19-9 was abnormally high at 17,539.1 U/ml. Although the possibility of malignancy was considered, there was no obvious malignant lesion on imaging; the patient was diagnosed with cholecystitis, and laparoscopic cholecystectomy was performed the day after admission. The surgical specimen showed no malignant findings either grossly or in the final pathological examination. There were no complications in the patient's postoperative course, and he was discharged from the hospital on the third postoperative day. CA19-9 level quickly returned to within normal range after surgery. CONCLUSIONS: In acute cholecystitis, CA19-9 levels exceeding 10,000 U/ml are very rare. We report a case of acute cholecystitis without malignant findings despite a high CA19-9 level.

2.
Stem Cell Res Ther ; 14(1): 83, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-37046329

RESUMO

Stem cell replacement holds the potential for sensorineural hearing loss (SNHL) treatment. However, its translation into clinical practice requires strategies for improving stem cell survival following intracochlear transplantation. Considering recent findings showing that the inner ear contains a resident population of immune cells, we hypothesized that immune evasion would improve the survival and residence time of transplanted stem cells in the cochlea, potentially leading to better outcomes. To test this, we leveraged genetic engineering techniques to develop hypoimmunogenic human-induced pluripotent stem cells (hi-iPSC), which lack human leukocyte antigen expression. We found that gene editing does not affect the biological properties of hi-iPSCs, including their capacity to differentiate into otic neural progenitors (ONPs). Compared to wild-type ONPs, more hypoimmunogenic ONPs (derived from hi-iPSCs) were found in the inner ear of immunocompetent mice ten days following cochlear xenotransplantation. This approach may open a new avenue for experimental and clinical SNHL treatments.


Assuntos
Perda Auditiva , Células-Tronco Pluripotentes Induzidas , Camundongos , Humanos , Animais , Transplante Heterólogo , Diferenciação Celular , Perda Auditiva/metabolismo , Transplante de Células-Tronco/métodos , Células-Tronco Pluripotentes Induzidas/metabolismo
3.
Adv Exp Med Biol ; 1389: 45-68, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36350506

RESUMO

In mammals, three major DNA methyltransferases, Dnmt1, Dnmt3a, and Dnmt3b, have been identified. Dnmt3a and Dnmt3b are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. Dnmt3-like (Dnmt3l), which is a member of the Dnmt3 family but does not possess DNA methylation activity, was reported to be indispensable for global methylation in germ cells. Once the DNA methylation patterns are established, maintenance-type DNA methyltransferase Dnmt1 faithfully propagates them to the next generation via replication. All Dnmts possess multiple domains. For instance, Dnmt3a and Dnmt3b each contain a Pro-Trp-Trp-Pro (PWWP) domain that recognizes the histone H3K36me2/3 mark, an Atrx-Dnmt3-Dnmt3l (ADD) domain that recognizes unmodified histone H3 tail, and a catalytic domain that methylates CpG sites. Dnmt1 contains an N-terminal independently folded domain (NTD) that interacts with a variety of regulatory factors, a replication foci-targeting sequence (RFTS) domain that recognizes the histone H3K9me3 mark and H3 ubiquitylation, a CXXC domain that recognizes unmodified CpG DNA, two tandem Bromo-Adjacent-homology (BAH1 and BAH2) domains that read the H4K20me3 mark with BAH1, and a catalytic domain that preferentially methylates hemimethylated CpG sites. In this chapter, the structures and functions of these domains are described.


Assuntos
Metilação de DNA , Histonas , Animais , Histonas/metabolismo , DNA Metiltransferase 3A , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/química , DNA (Citosina-5-)-Metiltransferase 1/genética , Metilases de Modificação do DNA/genética , DNA/metabolismo , Mamíferos/genética
4.
Biologicals ; 56: 67-83, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30150108

RESUMO

Sessions included an overview of past cell therapy (CT) conferences sponsored by the International Alliance for Biological Standardization (IABS). The sessions highlighted challenges in the field of human pluripotent stem cells (hPSCs) and also addressed specific points on manufacturing, bioanalytics and comparability, tumorigenicity testing, storage, and shipping. Panel discussions complemented the presentations. The conference concluded that a range of new standardization groups is emerging that could help the field, but ways must be found to ensure that these efforts are coordinated. In addition, there are opportunities for regulatory convergence starting with a gap analysis of existing guidelines to determine what might be missing and what issues might be creating divergence. More specific global regulatory guidance, preferably from WHO, would be welcome. IABS and the California Institute for Regenerative Medicine (CIRM) will explore with stakeholders the development of a practical and innovative road map to support early CT product (CTP) developers.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Células-Tronco Pluripotentes , Testes de Carcinogenicidade , Guias como Assunto , Humanos , Controle de Qualidade , Medicina Regenerativa
5.
Adv Exp Med Biol ; 945: 63-86, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27826835

RESUMO

In mammals, three DNA methyltransferases, Dnmt1, Dnmt3a, and Dnmt3b, have been identified. Dnmt3a and Dnmt3b are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. Dnmt3-like (Dnmt3l), which is a member of the Dnmt3 family but does not possess DNA methylation activity, was reported to be indispensable for global methylation in germ cells. Once the DNA methylation patterns are established, maintenance-type DNA methyltransferase Dnmt1 faithfully propagates them to the next generation via replication. All Dnmts possess multiple domains, and in this chapter, the structures and functions of these domains are described.


Assuntos
DNA (Citosina-5-)-Metiltransferases/química , Metilação de DNA/genética , Domínios Proteicos/genética , Animais , DNA/genética , DNA/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA Metiltransferase 3A , Implantação do Embrião/genética , Humanos , Camundongos , Estrutura Secundária de Proteína , DNA Metiltransferase 3B
6.
PLoS One ; 10(9): e0137509, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26383849

RESUMO

In mammals, DNA methylation plays important roles in embryogenesis and terminal differentiation via regulation of the transcription-competent chromatin state. The methylation patterns are propagated to the next generation during replication by maintenance DNA methyltransferase, Dnmt1, in co-operation with Uhrf1. In the N-terminal regulatory region, Dnmt1 contains proliferating cell nuclear antigen (PCNA)-binding and replication foci targeting sequence (RFTS) domains, which are thought to contribute to maintenance methylation during replication. To determine the contributions of the N-terminal regulatory domains to the DNA methylation during replication, Dnmt1 lacking the RFTS and/or PCNA-binding domains was ectopically expressed in embryonic stem cells, and then the effects were analyzed. Deletion of both the PCNA-binding and RFTS domains did not significantly affect the global DNA methylation level. However, replication-dependent DNA methylation of the differentially methylated regions of three imprinted genes, Kcnq1ot1/Lit1, Peg3, and Rasgrf1, was impaired in cells expressing the Dnmt1 with not the PCNA-binding domain alone but both the PCNA-binding and RFTS domains deleted. Even in the absence of Uhrf1, which is a prerequisite factor for maintenance DNA methylation, Dnmt1 with both the domains deleted apparently maintained the global DNA methylation level, whilst the wild type and the forms containing the RFTS domain could not perform global DNA methylation under the conditions used. This apparent maintenance of the global DNA methylation level by the Dnmt1 lacking the RFTS domain was dependent on its own DNA methylation activity as well as the presence of de novo-type DNA methyltransferases. We concluded that the RFTS domain, not the PCNA-binding domain, is solely responsible for the replication-coupled DNA methylation. Furthermore, the RFTS domain acts as a safety lock by protecting the genome from replication-independent DNA methylation.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Células-Tronco Embrionárias Murinas/metabolismo , Animais , Sítios de Ligação , Células Cultivadas , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/análise , DNA (Citosina-5-)-Metiltransferases/genética , Replicação do DNA , Deleção de Genes , Impressão Genômica , Camundongos , Estrutura Terciária de Proteína
7.
Nucleic Acids Res ; 43(21): 10200-12, 2015 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-26319017

RESUMO

The α, ß and γ isoforms of mammalian heterochromatin protein 1 (HP1) selectively bind to methylated lysine 9 of histone H3 via their chromodomains. Although the phenotypes of HP1-knockout mice are distinct for each isoform, the molecular mechanisms underlying HP1 isoform-specific function remain elusive. In the present study, we found that in contrast to HP1α, HP1γ could not bind tri-methylated H3 lysine 9 in a reconstituted tetra-nucleosomes when the nucleosomes were in an uncompacted state. The hinge region connecting HP1's chromodomain and chromoshadow domain contributed to the distinct recognition of the nucleosomes by HP1α and HP1γ. HP1γ, but not HP1α, was strongly enhanced in selective binding to tri-methylated lysine 9 in histone H3 by the addition of Mg(2+) or linker histone H1, which are known to induce compaction of nucleosomes. We propose that this novel property of HP1γ recognition of lysine 9 in the histone H3 tail in different nucleosome structures plays a role in reading the histone code.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Histonas/metabolismo , Nucleossomos/metabolismo , Homólogo 5 da Proteína Cromobox , Histonas/química , Humanos , Lisina/metabolismo , Magnésio/química , Metilação , Ligação Proteica , Isoformas de Proteínas/metabolismo , Multimerização Proteica
8.
PLoS One ; 9(2): e88891, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24558442

RESUMO

The mechanistic target of rapamycin (mTOR) functions as a component of two large complexes, mTORC1 and mTORC2, which play crucial roles in regulating cell growth and homeostasis. However, the molecular mechanisms by which mTOR controls cell proliferation remain elusive. Here we show that the FoxO3a transcription factor is coordinately regulated by mTORC1 and mTORC2, and plays a crucial role in controlling cell proliferation. To dissect mTOR signaling, mTORC1 was specifically inactivated by depleting p18, an essential anchor of mTORC1 on lysosomes. mTORC1 inactivation caused a marked retardation of cell proliferation, which was associated with upregulation of cyclin-dependent kinase inhibitors (CDKIs). Although Akt was activated by mTORC1 inactivation, FoxO3a was upregulated via an epigenetic mechanism and hypophosphorylated at Ser314, which resulted in its nuclear accumulation. Consistently, mTORC1 inactivation induced downregulation of serum- and glucocorticoid-inducible kinase 1 (SGK1), the kinase responsible for Ser314 phosphorylation. Expression of FoxO3a mutated at Ser314 suppressed cell proliferation by inducing CDKI expression. SGK1 overexpression suppressed CDKI expression in p18-deficient cells, whereas SGK1 knockdown induced CDKI expression in wild-type cells, resulting in the suppression of cell proliferation. These results suggest that mTORC1, in coordination with mTORC2, controls cell proliferation by regulating FoxO3a gene expression and SGK1-mediated phosphorylation of FoxO3a at Ser314.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular , Núcleo Celular/metabolismo , Proliferação de Células , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Proteína Forkhead Box O3 , Regulação da Expressão Gênica , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , Fosforilação , Regulação para Cima
9.
PLoS One ; 8(12): e82961, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24340069

RESUMO

Hydroxymethylcytosine in the genome is reported to be an intermediate of demethylation. In the present study, we demonstrated that maintenance methyltransferase Dnmt1 scarcely catalyzed hemi-hydroxymethylated DNA and that the hemi-hydroxymethylated DNA was not selectively recognized by the SRA domain of Uhrf1, indicating that hydroxymethylcytosine is diluted in a replication-dependent manner. A high level of 5-hydroxymethylcytosine in mouse embryonic stem cells was produced from the methylcytosine supplied mainly by de novo-type DNA methyltransferases Dnmt3a and Dnmt3b. The promoter regions of the HoxA gene cluster showed a high hydroxymethylation level whilst the methylcytosine level was quite low, suggesting that methylated CpG is actively hydroxylated during proliferation. All the results indicate that removal and production of hydroxymethylcytosine are regulated in replication-dependent manners in mouse embryonic stem cells.


Assuntos
Ciclo Celular , Citosina/análogos & derivados , Células-Tronco Embrionárias/citologia , 5-Metilcitosina/análogos & derivados , Animais , Proteínas Estimuladoras de Ligação a CCAAT , Proliferação de Células , Separação Celular , Ilhas de CpG , Citosina/química , DNA/análise , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , DNA Metiltransferase 3A , Replicação do DNA , Citometria de Fluxo , Camundongos , Camundongos Knockout , Família Multigênica , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Estrutura Terciária de Proteína , Ubiquitina-Proteína Ligases , DNA Metiltransferase 3B
10.
J Gastroenterol ; 48(11): 1234-41, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23338487

RESUMO

BACKGROUND: We aimed to evaluate the efficacy of a new combination antiemetic therapy comprising aprepitant, granisetron, and dexamethasone in gastric cancer patients undergoing chemotherapy with cisplatin and S-1. METHODS: Gastric cancer patients scheduled to receive their first course of chemotherapy with cisplatin (60 mg/m(2)) and S-1 (80 mg/m(2)) were treated with a new combination antiemetic therapy aprepitant, granisetron, and dexamethasone on day 1; aprepitant and dexamethasone on days 2 and 3; and dexamethasone on day 4. The patients reported vomiting, nausea, use of rescue therapy, and change in the amount of diet intake, and completed the Functional Living Index-Emesis (FLIE) questionnaire. The primary endpoint was complete response (CR; no emesis and use of no rescue antiemetics) during the overall study phase (0-120 h after cisplatin administration). The secondary endpoints included complete protection (CP; CR plus no significant nausea); change in the amount of diet intake; and the impact of chemotherapy-induced nausea and vomiting (CINV) on daily life during the overall, acute (0-24 h), and delayed (24-120 h) phases. RESULTS: Fifty-three patients were included. CR was achieved in 88.7, 98.1, and 88.7% of patients in the overall, acute, and delayed phases, respectively. The corresponding rates of CP were 67.9, 96.2, and 67.9%. Approximately half of the patients had some degree of anorexia. FLIE results indicated that 79.5% of patients reported "minimal or no impact of CINV on daily life". CONCLUSIONS: Addition of aprepitant to standard antiemetic therapy was effective in gastric cancer patients undergoing treatment with cisplatin and S-1.


Assuntos
Antieméticos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Náusea/prevenção & controle , Neoplasias Gástricas/tratamento farmacológico , Vômito/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Antieméticos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Aprepitanto , Cisplatino/administração & dosagem , Dexametasona/efeitos adversos , Dexametasona/uso terapêutico , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Granisetron/efeitos adversos , Granisetron/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Morfolinas/efeitos adversos , Morfolinas/uso terapêutico , Náusea/induzido quimicamente , Estadiamento de Neoplasias , Ácido Oxônico/administração & dosagem , Estudos Prospectivos , Psicometria , Qualidade de Vida , Neoplasias Gástricas/patologia , Tegafur/administração & dosagem , Resultado do Tratamento , Vômito/induzido quimicamente
11.
J Biol Chem ; 288(9): 6351-62, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23316048

RESUMO

The methyl-CpG binding domain (MBD) protein MBD4 participates in DNA repair as a glycosylase that excises mismatched thymine bases in CpG sites and also functions in transcriptional repression. Unlike other MBD proteins, MBD4 recognizes not only methylated CpG dinucleotides ((5m)CG/(5m)CG) but also T/G mismatched sites generated by spontaneous deamination of 5-methylcytosine ((5m)CG/TG). The glycosylase activity of MBD4 is also implicated in active DNA demethylation initiated by the deaminase-catalyzed conversion of 5-methylcytosine to thymine. Here, we report the crystal structures of the MBD of MBD4 (MBDMBD4) complexed with (5m)CG/(5m)CG and (5m)CG/TG. The crystal structures show that the DNA interface of MBD4 has flexible structural features and harbors an extensive water network that supports its dual base specificities. Combined with the results of biochemical analyses, the crystal structure of MBD4 bound to 5-hydroxymethylcytosine further demonstrates that MBDMBD4 is able to recognize a wide range of 5-methylcytosine modifications through the unique water network. The versatile base recognition ability of MBDMBD4 implies multifunctional roles for MBD4 in the regulation of dynamic DNA methylation patterns coupled with deamination and/or oxidation of 5-methylcytosine.


Assuntos
5-Metilcitosina/química , Citosina/análogos & derivados , Endodesoxirribonucleases/química , 5-Metilcitosina/metabolismo , Animais , Cristalografia por Raios X , Citosina/química , Citosina/metabolismo , Metilação de DNA/fisiologia , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Humanos , Camundongos , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
12.
Curr Top Microbiol Immunol ; 367: 237-52, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23197305

RESUMO

During newt lens regeneration a unique transdifferentiation event occurs. In this process, dorsal iris pigmented epithelial cells transdifferentiate into lens cells. This system should provide a new insight into cellular plasticity in basic and applied research. Recently, a series of approaches to study epigenetic reprogramming during transdifferentiation have been performed. In this review, we introduce the regulation of dynamic regulation of core-histone modifications and the emergence of an oocyte-type linker histone during transdifferentiation. Finally, we show supporting evidence that there are common strategies of reprogramming between newt somatic cell in transdifferentiation and oocytes after somatic cell nuclear transfer.


Assuntos
Epigenômica , Cristalino/fisiologia , Regeneração , Salamandridae/fisiologia , Sequência de Aminoácidos , Animais , Transdiferenciação Celular , Reprogramação Celular , Histonas/fisiologia , Dados de Sequência Molecular
13.
PeerJ ; 1: e230, 2013 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-24432195

RESUMO

Haploid embryonic stem cells (ESCs) are useful for studying mammalian genes because disruption of only one allele can cause loss-of-function phenotypes. Here, we report the use of haploid ESCs and the CRISPR RNA-guided Cas9 nuclease gene-targeting system to manipulate mammalian genes. Co-transfection of haploid ESCs with vectors expressing Cas9 nuclease and single-guide RNAs (sgRNAs) targeting Tet1, Tet2, and Tet3 resulted in the complete disruption of all three genes and caused a loss-of-function phenotype with high efficiency (50%). Co-transfection of cells with vectors expressing Cas9 and sgRNAs targeting two loci on the same chromosome resulted in the creation of a large chromosomal deletion and a large inversion. Thus, the use of the CRISPR system in combination with haploid ESCs provides a powerful platform to manipulate the mammalian genome.

14.
Gan To Kagaku Ryoho ; 40(12): 2092-4, 2013 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-24394023

RESUMO

A 74-year-old man was admitted to the hospital because of abdominal fullness and constipation. Endoscopy and abdominal computed tomography (CT) scans showed an advanced sigmoid colonic cancer with multiple lung and liver metastases and peritoneal dissemination. Sigmoid resection was performed to relieve ileus. Postoperative chemotherapy was administered for metastatic lesions. We administered systemic chemotherapy with tegafur-uraci(l UFT)/UZEL( 10 months), oxaliplatin with fluorouracil (5-FU) and folinic acid (FOLFOX; 11 courses), irinotecan with 5-FU and folinic acid (FOLFIRI; 13 courses), irinotecan plus S-1 (IRIS; 23 courses), bevacizumab (32 courses), cetuximab (29 courses), and peritoneal infusion of paclitaxel( 65 courses). The patient survived for 5 years after the initial treatment.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias do Colo Sigmoide/tratamento farmacológico , Idoso , Progressão da Doença , Evolução Fatal , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Masculino , Estadiamento de Neoplasias , Neoplasias Peritoneais/secundário , Neoplasias do Colo Sigmoide/patologia , Fatores de Tempo
15.
PLoS One ; 7(9): e44889, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23028663

RESUMO

We screened 46 novel anilinoquinazoline derivatives for activity to inhibit proliferation of a panel of human cancer cell lines. Among them, Q15 showed potent in vitro growth-inhibitory activity towards cancer cell lines derived from colorectal cancer, lung cancer and multiple myeloma. It also showed antitumor activity towards multiple myeloma KMS34 tumor xenografts in lcr/scid mice in vivo. Unlike the known anilinoquinazoline derivative gefitinib, Q15 did not inhibit cytokine-mediated intracellular tyrosine phosphorylation. Using our mRNA display technology, we identified hCAP-G2, a subunit of condensin II complex, which is regarded as a key player in mitotic chromosome condensation, as a Q15 binding partner. Immunofluorescence study indicated that Q15 compromises normal segregation of chromosomes, and therefore might induce apoptosis. Thus, our results indicate that hCAP-G2 is a novel therapeutic target for development of drugs active against currently intractable neoplasms.


Assuntos
Adenosina Trifosfatases/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Proteínas de Ligação a DNA/química , Complexos Multiproteicos/química , Subunidades Proteicas/metabolismo , Tiazóis/metabolismo , Tiazóis/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Segregação de Cromossomos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Masculino , Camundongos , Mitose/efeitos dos fármacos , Mieloma Múltiplo/patologia , Ligação Proteica , Risco , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Biochem J ; 437(1): 141-8, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21510846

RESUMO

The Dnmt3a gene, which encodes de novo-type DNA methyltransferase, encodes two isoforms, full-length Dnmt3a and Dnmt3a2, which lacks the N-terminal 219 amino acid residues. We found that Dnmt3a showed higher DNA-binding and DNA-methylation activities than Dnmt3a2. The N-terminal sequence from residues 1 to 211 was able to bind to DNA, but could not distinguish methylated and unmethylated CpG. Its binding to DNA was inhibited by a major groove binder. Four basic amino acid residues, Lys51, Lys53, Arg177 and Arg179, in the N-terminal region were crucial for the DNA-binding activity. The ectopically expressed N-terminal sequence (residues 1-211) was localized in nuclei, whereas that harbouring mutations at the four basic amino acid residues was also detected in the cytoplasm. The DNA-methylation activity of Dnmt3a with the mutations was suppressed under physiological salt conditions, which is similar that of Dnmt3a2. In addition, ectopically expressed Dnmt3a with mutations, as well as Dnmt3a2, could not be retained efficiently in nuclei on salt extraction. We conclude that the DNA-binding activity of the N-terminal domain contributes to the DNA-methyltransferase activity via anchoring of the whole molecule to DNA under physiological salt conditions.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA/metabolismo , Sítios de Ligação , Células Cultivadas , DNA/química , Metilação de DNA , DNA Metiltransferase 3A , Células HeLa , Humanos , Estrutura Terciária de Proteína
17.
J Biol Chem ; 286(18): 15698-706, 2011 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-21388951

RESUMO

The transmembrane adaptor protein Cbp (or PAG1) functions as a suppressor of Src-mediated tumor progression by promoting the inactivation of Src. The expression of Cbp is down-regulated in Src-transformed cells and in various human cancer cells, suggesting a potential role for Cbp as a tumor suppressor. However, the mechanisms underlying the down-regulation of Cbp remain unknown. The present study shows that Cbp expression is down-regulated by epigenetic histone modifications via the MAPK/PI3K pathway. In mouse embryonic fibroblasts, transformation by oncogenic Src and Ras induced a marked down-regulation of Cbp expression. The levels of Cbp expression were inversely correlated with the activity of MEK and Akt, and Cbp down-regulation was suppressed by inhibiting MEK and PI3K. Src transformation did not affect the stability of Cbp mRNA, the transcriptional activity of the cbp promoter, or the DNA methylation status of the cbp promoter CpG islands. However, Cbp expression was restored by treatment with histone deacetylase (HDAC) inhibitors and by siRNA-mediated knockdown of HDAC1/2. Src transformation significantly decreased the acetylation levels of histone H4 and increased the trimethylation levels of histone H3 lysine 27 in the cbp promoter. EGF-induced Cbp down-regulation was also suppressed by inhibiting MEK and HDAC. Furthermore, the inhibition of MEK or HDAC restored Cbp expression in human cancer cells harboring Cbp down-regulation through promoter hypomethylation. These findings suggest that Cbp down-regulation is primarily mediated by epigenetic histone modifications via oncogenic MAPK/PI3K pathways in a subset of cancer cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Epigênese Genética , Histonas/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas de Membrana/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Supressoras de Tumor/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Embrião de Mamíferos/metabolismo , Fibroblastos/metabolismo , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/antagonistas & inibidores , Histona Desacetilase 2/genética , Histona Desacetilase 2/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Histonas/genética , Humanos , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Proteínas de Membrana/genética , Metilação/efeitos dos fármacos , Camundongos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/genética , Neoplasias/genética , Fosfatidilinositol 3-Quinases/genética , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas pp60(c-src)/genética , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas ras/genética , Proteínas ras/metabolismo
18.
Gan To Kagaku Ryoho ; 36(11): 1919-22, 2009 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-19920401

RESUMO

A 77-year-old woman was admitted to our hospital because of para-aortic lymph node swelling pointed out by abdominal CT scan. She had a previous history of colectomy with a diagnosis of ascending colonic cancer 8 years later. Pathological examination was a moderately-differentiated adenocarcinoma with lymph node metastasis (Stage IIIa). PET scan demonstrated hot spots of para-aortic and left supra-clavicular lesions. The serum CEA and CA19-9 levels regained the normal value. No malignancy was recognized by endoscopic examinations of upper and lower gastrointestinal tract. We supported that swelling of lymph nodes were due to lymphoma. Laparotomic biopsy of para-aortic lymph node was done after 6 months. Histologically metastatic adenocarcinoma was recognized. We performed systemic chemotherapy of UFT and LV on recurrent colonic cancer. After 9 courses, spots of para-aortic and left supra-clavicular lesions disappeared on the PET scan. Lymph node metastasis was not found by CT scan 20 months after beginning chemotherapy. Thus, we consider that this therapy was recommendable for the treatment of an older adult patient with recurrent colonic cancer.


Assuntos
Adenocarcinoma/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo/patologia , Metástase Linfática , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/cirurgia , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Aorta Abdominal , Colectomia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/cirurgia , Feminino , Humanos , Leucovorina/administração & dosagem , Tomografia por Emissão de Pósitrons , Tegafur/administração & dosagem , Fatores de Tempo , Uracila/administração & dosagem
19.
J Surg Oncol ; 100(4): 311-6, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19697437

RESUMO

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. New bidirectional chemotherapy (neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)) was developed. The aim of the present study was to assess the safety and efficacy of NIPS and to show the selection for cytoreductive surgery on PC from gastric cancer. Seventy-nine patients with PC from gastric cancer were treated with NIPS. A peritoneal port system was introduced into the abdominal cavity. The peritoneal wash cytological examination through a port was done before and after NIPS. The patients were treated with oral TS-1 twice a daily for 21 days, followed by a 1-week rest. On day 1, 8, and 15 from the start of oral TS-1 administration, 30 mg/m(2) of Docetaxel and 30 mg/m(2) of cisplatinum with 500 ml of saline were introduced into the peritoneal cavity through the port. A median course of oral TS-1 was 2.1 course and a median time of IP chemoterapy was 5.8. Peritoneal free cancer cells (PFCCs) had been detected in 65 (82.2%) patients before NIPS, and the positive cytology changed to be negative in 41 (63.0%) patients after NIPS. After NIPS, 41 patients underwent laparotomy, and complete cytoreduction was done in 32 (78%) patients. Complete cytoreduction was done in 27 (51.9%) of 52 patients with negative cytology but in only 4 (14.8%) of 27 patients with positive cytology (P < 0.001). Patients with negative cytology after NIPS survived significantly longer than those with positive cytology. The adverse effects after NIPS were mild and there was no treatment-related deaths. The grade 3/4 hematological adverse effects were found in 2 (2.6%) patients. Grade 3 renal toxicity and port site infection was found in three patients, respectively. NIPS using a port system is a safe and effective treatment for PC. Peritoneal wash cytology through a port system is a good indicator to select the patients to perform cytoreductive surgery.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia do Câncer por Perfusão Regional , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Adulto , Idoso , Cisplatino/administração & dosagem , Terapia Combinada , Docetaxel , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Seleção de Pacientes , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/cirurgia , Prognóstico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Taxa de Sobrevida , Taxoides/administração & dosagem
20.
Gan To Kagaku Ryoho ; 36(7): 1191-4, 2009 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-19620816

RESUMO

A 58-year-old woman was admitted to the hospital because of abdominal fullness and anorexia. Abdominal CT scan revealed pancreatic cancer with massive ascites showing peritoneal dissemination, combined with lymph node and liver metastases. Cytology of ascites showed malignancy. Abnormally high values of CA19-9 (1,908 U/mL) and CA125 (545 U/mL) were detected in serum. Histologically, metastatic adenocarcinoma was recognized by laparoscopic biopsy of peritoneal dissemination. We performed systemic chemotherapy of S-1, gemcitabine and peritoneal infusion of paclitaxel for nonresected pancreatic cancer. After 5 courses, ascites disappeared and the serum CA19-9 and CA125 levels regained their normal value. Peritoneal seeding was not found by second laparoscopic examination 20 months after beginning chemotherapy. Thus, we consider the patient had an effective response, and performed distal pancreatectomy and proximal resection of the stomach. Histological examination of the primary lesion revealed no cancer cells where fibrosis presented.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Hepáticas/secundário , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Peritoneais/secundário , Adenocarcinoma/patologia , Antimetabólitos Antineoplásicos/administração & dosagem , Antígeno Ca-125/sangue , Antígeno CA-19-9/sangue , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Combinação de Medicamentos , Feminino , Humanos , Pessoa de Meia-Idade , Ácido Oxônico/administração & dosagem , Paclitaxel/administração & dosagem , Neoplasias Pancreáticas/patologia , Tegafur/administração & dosagem , Gencitabina
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