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1.
Zhongguo Zhen Jiu ; 42(5): 541-8, 2022 May 12.
Artigo em Chinês | MEDLINE | ID: mdl-35543945

RESUMO

OBJECTIVE: To observe the effect of fire needling on psoriasis-like lesion and the signal transducer and activator of transcription 3 (STAT3) pathway in mice and compare the therapeutic effect between different interventions of fire needling therapy (surrounding technique of fire needling, fire needling at "Dazhui" [GV 14] and "Zusanli" [ST 36]). METHODS: Thirty male BALB/c mice were randomized into a blank group, a model group, a dexamthasone group, a surrounding technique group and an acupoint group, 6 mice in each one. Except the blank group, the mice in the rest groups were established as psoriasis-like lesion model by topical application with imiquimod cream, once daily, consecutively for 8 days. From day 4 to day 8, in the dexamthasone group, gastric infusion with 0.2 mL dexamthasone was administered, once daily. On day 4, 6 and 8, in the surrounding technique group, fire needling was exerted around the skin lesion; and fire needling was applied to "Dazhui" (GV 14) and "Zusanli" (ST 36) in the acupoint group, once a day. The changes in skin lesion on the dorsal parts of mice were observed in each group to score the psoriasis area and severity index (PASI). Using HE staining, the dermal morphological changes and epidermal thickness were observed in the mice of each group. The positive expression of proliferating cell-associated antigen Ki-67 was determined by immunofluorescence. Immunohistochemistry method was used to determine the expressions of , and T cells of skin tissue in each group. Using real-time PCR, the expressions of interleukin (IL)-17, IL-22, tumor necrosis factor α(TNF-α) mRNA were determined. Western blot method was adopted to determine the protein expressions of STAT3 and p-STAT3 in skin tissue in each group. RESULTS: Compared with the blank group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all increased in the mice of the model group (P<0.01). Except for the erythema scores of the dexamethasone group and the surrounding technique group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all decreased in each intervention group as compared with the model group (P<0.01). The infiltration scores and the total scores in the dexamethasone group and the acupoint group were lower than those in the surrounding technique group respectively (P<0.01, P<0.05). In comparison with the blank group, Ki-67 positive cell numbers and the numbers of , and T cells in skin tissue were increased in the mice of the model group (P<0.01). Ki-67 positive cell numbers and the numbers of , and T cells were reduced in each intervention group as compared with the model group (P<0.01), and the numbers of and T cells in the acupoint group were less than the surrounding technique group (P<0.01). Compared with the blank group, the mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all increased in the model group (P<0.01). The mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all decreased in each intervention group as compared with the model group (P<0.01, P<0.05). The mRNA expressions of IL-17, IL-22 and TNF-α in the acupoint group, as well as mRNA expression of IL-17 in the surrounding technique group were all lower than the dexamethasone group (P<0.01), while, the mRNA expression of IL-22 in the acupoint group was lower than the surrounding technique group (P<0.01). CONCLUSION: Fire needling therapy improves skin lesion severity in imiquimod induced psoriasis-like lesion of the mice, which is probably related to the inhibition of STAT3 pathway activation and the decrease of Th17 inflammatory factors expression. The systemic regulation of fire needling at "Dazhui" (GV 14) and "Zusanli" (ST 36) is superior to the local treatment.


Assuntos
Interleucina-17 , Psoríase , Animais , Dexametasona/metabolismo , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Imiquimode/efeitos adversos , Imiquimode/metabolismo , Interleucina-17/metabolismo , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , RNA Mensageiro/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/farmacologia , Pele/metabolismo , Pele/patologia , Fator de Necrose Tumoral alfa/metabolismo
2.
ACS Nano ; 16(4): 5851-5866, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35412799

RESUMO

Conventional cancer targeting methodology needs to be reformed to overcome the intrinsic barriers responsible for poor targeting efficiency. This study describes a concept of self-reinforced cancer targeting (SRCT) by correlating targeting with therapy in a reciprocally enhancing manner. SRCT is achieved on the basis of two prerequisites: (1) target molecules have to be expressed on cancer cell membranes but not on normal cells, and (2) notably, their expression on cancer cells must be actively upregulated in response to cellular attack by cancer treatments. As a proof-of-concept, a GRP78-targeting nanovehicle for chemotherapy was designed. Resultant data showed that chemotherapeutic drugs could effectively elevate GRP78 expression on the plasma membranes of cancer cells while having minimal influence on normal cells. DOX pretreatment of cancer cells and tumor tissues can greatly increase the targeting efficacy and therapeutic performance of the prepared GRP78-targeting nanomedicine while somewhat disfavoring the nontargeting counterpart. In vivo and in vitro results demonstrated that this GRP78-targeting nanomedicine could accurately target cancer cells to not only implement chemotherapy but also induce GRP78 upregulation on cancer cells, eventually benefiting continuous cancer-cell-targeted attack by the nanomedicines remaining in the blood circulation or administered in the next dose. The GRP78-targeting nanomedicine displays much better antitumor performance compared with the nontargeting counterpart. SRCT is expected to advance cancer-targeted therapy based on the positive dependency between targeting and therapeutic modalities.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Retroalimentação , Neoplasias/tratamento farmacológico , Nanomedicina/métodos , Linhagem Celular Tumoral
3.
Zhongguo Zhen Jiu ; 42(1): 66-72, 2022 Jan 12.
Artigo em Chinês | MEDLINE | ID: mdl-35025160

RESUMO

OBJECTIVE: To observe the effect of moxibustion on skin lesions and immune inflammatory response in psoriasis mice, and to explore the possible mechanism of moxibustion for psoriasis. METHODS: A total of 32 male BALB/c mice were randomly divided into a normal group, a model group, a moxibustion group and a medication group, 8 mice in each group. Psoriasis model was induced by applying 5% imiquimod cream on the back for 7 days in the model group, the moxibustion group and the medication group. At the same time of model establishment, the moxibustion group was treated with suspension moxibustion on skin lesions on the back, 20 min each time, once a day; the medication group was treated with 1 mg/kg methotrexate tablet solution by gavage, once a day. Both groups were intervened for 7 days. The daily changes of skin lesions were observed, and the psoriasis area and severity index (PASI) score was evaluated; the histopathological changes of skin lesions were observed by HE staining; the positive expression of proliferating cell nuclear antigen (PCNA) and T lymphocyte surface marker CD3 were detected by immunohistochemistry; the expression level of serum interleukin (IL) -17A was detected by ELISA, and the relative expressions of tumor necrosis factor-α (TNF-α), IL-1ß and IL-6 mRNA in skin lesions were detected by real-time PCR. RESULTS: The increased and hypertrophy scale, dry skin, red and swollen epidermis and obvious infiltration were observed in the model group, and each score and total score of PASI were higher than those in the normal group (P<0.01). The scale score, infiltration score, and total score of PASI in the moxibustion group were lower than those in the model group (P<0.01); the infiltration score and total score of PASI in the medication group were lower than those in the model group (P<0.01, P<0.05). The inflammatory cell infiltration in the model group was obvious, and the thickness of epidermal layer was increased compared with that in the normal group (P<0.01); the inflammatory cell infiltration and Munro micro abscess were decreased in the moxibustion group and the medication group, and the thickness of epidermal layer was decreased compared with that in the model group (P<0.01). Compared with the normal group, the positive cell number of PCNA and T was increased (P<0.01), and the body mass was decreased, and the spleen index was increased (P<0.01), and the expression of serum IL-17A and the relative expression of TNF-α, IL-1ß and IL-6 mRNA in the skin lesions was increased in the model group (P<0.01). Compared with the model group, the positive cell number of PCNA and T was reduced (P<0.01), and the spleen index and the relative expression of TNF-α, IL-1ß and IL-6 mRNA were reduced (P<0.01) in the moxibustion group and the medication group; the body mass of mice in the moxibustion group was higher than that in the model group (P<0.01); the content of serum IL-17A in the medication group was lower than that in the model group (P<0.01); the relative expression of TNF-α, IL-1ß mRNA in the moxibustion group was higher than that in the medication group (P<0.01). CONCLUSION: Moxibustion could effectively improve the scale and infiltration of skin lesions in psoriasis mice. Its mechanism may be related to inhibiting inflammatory response and regulating immunity.


Assuntos
Moxibustão , Psoríase , Animais , Imiquimode , Masculino , Camundongos , Psoríase/genética , Psoríase/terapia , Pele , Baço , Fator de Necrose Tumoral alfa/genética
4.
Nanoscale ; 12(5): 2966-2972, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31971210

RESUMO

Lactate, the main contributor to the acidic tumor microenvironment, not only promotes the proliferation of tumor cells, but also closely relates to tumor invasion and metastasis. Here, a tumor targeting nanoplatform, designated as Me&Flu@MSN@MnO2-FA, was fabricated for effective tumor suppression and anti-metastasis by interfering with lactate metabolism of tumor cells. Metformin (Me) and fluvastatin sodium (Flu) were incorporated into MnO2-coated mesoporous silicon nanoparticles (MSNs), the synergism between Me and Flu can modulate the pyruvate metabolic pathway to produce more lactate, and concurrently inhibit lactate efflux to induce intracellular acidosis to kill tumor cells. As a result of the restricted lactate efflux, the extracellular lactate concentration is reduced, and the ability of the tumor cells to migrate is also weakened. This ingenious strategy based on Me&Flu@MSN@MnO2-FA showed an obvious inhibitory effect on tumor growth and resistance to metastasis.


Assuntos
Fluvastatina , Lactatos/metabolismo , Compostos de Manganês , Metformina , Nanopartículas , Neoplasias , Microambiente Tumoral/efeitos dos fármacos , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Fluvastatina/química , Fluvastatina/farmacocinética , Fluvastatina/farmacologia , Ácido Fólico/metabolismo , Humanos , Compostos de Manganês/química , Compostos de Manganês/farmacocinética , Compostos de Manganês/farmacologia , Metformina/química , Metformina/farmacocinética , Metformina/farmacologia , Nanopartículas/química , Nanopartículas/uso terapêutico , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Porosidade , Silício/química , Silício/farmacocinética , Silício/farmacologia
5.
Biomaterials ; 234: 119772, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31945618

RESUMO

Photodynamic therapy (PDT) is a promising treatment modality for tumor suppression. However, the hypoxic state of most solid tumors might largely hinder the efficacy of PDT. Here, a functional covalent organic framework (COF) is fabricated to enhance PDT efficacy by remodeling the tumor extracellular matrix (ECM). Anti-fibrotic drug pirfenidone (PFD) is loaded in an imine-based COF (COFTTA-DHTA) and followed by the decoration of poly(lactic-co-glycolic-acid)-poly(ethylene glycol) (PLGA-PEG) to fabricate PFD@COFTTA-DHTA@PLGA-PEG, or PCPP. After injected intravenously, PCPP can accumulate and release PFD in tumor sites, leading to down-regulation of ECM compenents such as hyaluronic acid (HA) and collagen I. Such depletion of tumor ECM reduces the intratumoral solid stress, a compressive force exerted by the ECM and cells, decompresses tumor blood vessels, and increases the density of effective vascular areas, resulting in significantly improved oxygen supply in tumor. Furthermore, PCPP-mediated tumor ECM depletion also enhances the tumor uptake of subsequently injected Protoporphyrinl IX (PPIX)-conjugated peptide formed nanomicelles (NM-PPIX) due to the improved enhanced permeability and retention (EPR) effect. Both the alleviated tumor hypoxia and improved tumor homing of photosensitizer (PS) molecules after PCPP treatment significantly increase the reactive oxygen species (ROS) generation in tumor and therefore realize greatly enhanced PDT effect of tumor in vivo.


Assuntos
Estruturas Metalorgânicas , Nanopartículas , Neoplasias , Fotoquimioterapia , Linhagem Celular Tumoral , Matriz Extracelular , Humanos , Neoplasias/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico
6.
ACS Nano ; 13(5): 5523-5532, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31046229

RESUMO

Carbon monoxide (CO) is regarded as a potential therapeutic agent with multiple beneficial functions for biomedical applications. In this study, a versatile CO nanogenerator (designated as PPOSD) was fabricated and developed for tumor therapy and anti-inflammation. Partially oxidized tin disulfide (SnS2) nanosheets (POS NSs) were decorated with a tumor-targeting polymer (polyethylene glycol-cyclo(Asp-d-Phe-Lys-Arg-Gly), PEG-cRGD), followed by the loading of chemotherapeutic drug doxorubicin (DOX) to prepare polymer@POS@DOX, or PPOSD. After injected intravenously, PPOSD could selectively accumulate in tumor tissue via the cRGD-mediated tumor recognition. Upon 561 nm laser irradiation, the POS moiety in PPOSD can photoreduce CO2 to CO, which significantly sensitized the chemotherapeutic effect of DOX. The POS in PPOSD can also act as a photothermal agent for effective photothermal therapy (PTT) of the tumor upon 808 nm laser irradiation. Furthermore, the generated CO can simultaneously decrease the inflammatory reaction caused by PTT. Blood analysis and hematoxylin-eosin staining of major organs showed that no obvious systemic toxicity was induced after the treatment, suggesting good biosafety of PPOSD. This versatile CO nanogenerator will find great potential for both enhanced tumor inhibition and anti-inflammation.


Assuntos
Monóxido de Carbono/farmacologia , Inflamação/tratamento farmacológico , Neoplasias/tratamento farmacológico , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Dióxido de Carbono/química , Monóxido de Carbono/química , Linhagem Celular Tumoral , Dissulfetos/química , Dissulfetos/farmacologia , Doxorrubicina/farmacologia , Humanos , Inflamação/patologia , Camundongos , Nanopartículas/química , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Nanoscale ; 11(4): 2027-2036, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30644936

RESUMO

An innovative tungsten-based multifunctional nanoplatform composed of polyethylene glycol (PEG)-modified tungsten nitride nanoparticles (WN NPs) is constructed for tumor treatment. The PEG-WN NPs not only possess strong near-infrared (NIR) absorbance, high photothermal conversion efficiency, and excellent photothermal stability, but also effectively inhibit tumor cells upon 808 nm laser irradiation. After coating with thiolated (2-hydroxypropyl)-ß-cyclodextrin (MUA-CD) on the surface, such a nanoplatform can also be used for drug delivery (such as DOX) and presents a synergistic tumor inhibition effect both in vitro and in vivo. Furthermore, the PEG-WN NPs present good contrasting capability for X-ray computed tomography (CT) and photoacoustic (PA) imaging. With PA/CT imaging, the tumor can be accurately positioned for precise treatment. It is worth mentioning that PEG-WN NPs are biodegradable and could be effectively excreted from the body with no appreciable toxicity in vivo. It is expected that this biocompatible multifunctional nanoplatform can serve as a potential candidate for tumor treatment in future clinical applications.


Assuntos
Nanopartículas Metálicas/química , Tungstênio/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Portadores de Fármacos/química , Feminino , Hipertermia Induzida , Lasers , Nanopartículas Metálicas/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Tamanho da Partícula , Técnicas Fotoacústicas , Fototerapia , Polietilenoglicóis/química , Nanomedicina Teranóstica , Tomografia Computadorizada por Raios X , beta-Ciclodextrinas/química
8.
Pharmacol Ther ; 191: 135-147, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29909235

RESUMO

Regulation of prostate cancer by androgen and androgen receptor (AR), and blockade of AR signaling by AR antagonists and steroidogenic enzyme inhibitors have been extensively studied. G protein-coupled receptors (GPCRs) are a family of membrane receptors that regulate almost all physiological processes. Nearly 40% of FDA-approved drugs in the market target GPCRs. A variety of GPCRs that mediate reproductive function have been demonstrated to be involved in the regulation of prostate cancer. These GPCRs include gonadotropin-releasing hormone receptor, luteinizing hormone receptor, follicle-stimulating hormone receptor, relaxin receptor, ghrelin receptor, and kisspeptin receptor. We highlight here GPCR regulation of prostate cancer by these GPCRs. Further therapeutic approaches targeting these GPCRs for the treatment of prostate cancer are summarized.


Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Receptores Acoplados a Proteínas G/efeitos dos fármacos , Androgênios/metabolismo , Animais , Desenvolvimento de Medicamentos/métodos , Humanos , Masculino , Terapia de Alvo Molecular , Neoplasias da Próstata/patologia , Receptores Androgênicos/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
9.
Proc Natl Acad Sci U S A ; 109(51): 20853-8, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23213213

RESUMO

One of the hurdles for practical application of induced pluripotent stem cells (iPSC) is the low efficiency and slow process of reprogramming. Octamer-binding transcription factor 4 (Oct4) has been shown to be an essential regulator of embryonic stem cell (ESC) pluripotency and key to the reprogramming process. To identify small molecules that enhance reprogramming efficiency, we performed a cell-based high-throughput screening of chemical libraries. One of the compounds, termed Oct4-activating compound 1 (OAC1), was found to activate both Oct4 and Nanog promoter-driven luciferase reporter genes. Furthermore, when added to the reprogramming mixture along with the quartet reprogramming factors (Oct4, Sox2, c-Myc, and Klf4), OAC1 enhanced the iPSC reprogramming efficiency and accelerated the reprogramming process. Two structural analogs of OAC1 also activated Oct4 and Nanog promoters and enhanced iPSC formation. The iPSC colonies derived using the Oct4-activating compounds along with the quartet factors exhibited typical ESC morphology, gene-expression pattern, and developmental potential. OAC1 seems to enhance reprogramming efficiency in a unique manner, independent of either inhibition of the p53-p21 pathway or activation of the Wnt-ß-catenin signaling. OAC1 increases transcription of the Oct4-Nanog-Sox2 triad and Tet1, a gene known to be involved in DNA demethylation.


Assuntos
Benzamidas/farmacologia , Reprogramação Celular/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Pluripotentes Induzidas/citologia , Fator 3 de Transcrição de Octâmero/metabolismo , Piridinas/farmacologia , Pirróis/farmacologia , Animais , Benzamidas/química , Diferenciação Celular , Química Farmacêutica/métodos , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Desenho de Fármacos , Fibroblastos/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Fator 4 Semelhante a Kruppel , Camundongos , Oxigenases de Função Mista , Proteína Homeobox Nanog , Proteínas Proto-Oncogênicas/metabolismo , Piridinas/química , Pirróis/química , Fatores de Transcrição SOXB1/metabolismo
10.
Zhonghua Xin Xue Guan Bing Za Zhi ; 37(8): 739-45, 2009 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-20021931

RESUMO

OBJECTIVE: Coronary arterial plaque rupture and secondary thrombosis are the major pathogenesis of acute coronary syndrome (ACS). Metalloprotease (MMPs) secreted by monocyte/macrophage was the main predisposing factor of the plaque rupture and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is involved in a variety of inflammatory cytokine gene transcriptional regulations. We explored the possible role of PPAR-gamma in the regulation of MMP-9 and TIMP-1 expressed by peripheral monocyte-derived macrophages (MDMs) from patients with ACS. METHODS: Peripheral blood mononuclear cells were isolated from 48 patients with ACS and 28 healthy controls and stimulated by macrophage colony-stimulating factor (0.1 microg/ml for 24 hours) to form MDMs. MDMs were then incubated under various concentrations of rosiglitazone (0, 1, 10, 20 micromol/L) for 48 hours. The concentrations of MMP-9 and TIMP-1 in the supernatant were measured by enzyme linked immunosorbent assay, and the mRNA expression of PPAR-gamma, MMP-9 by RT-PCR and nuclear factor-kappaB P65 (NF-kappaB P65) expression by immunohistochemistry. RESULTS: PPAR-gamma mRNA expression was significantly lower while NF-kappaB P65 and MMP-9 expression as well as MMP-9 and TIMP-1 concentrations in supernatant were significantly higher in ACS group than those in control group (all P < 0.05). After rosiglitazone intervention, PPAR-gamma mRNA expression was significantly upregulated in both ACS and control groups in a dose-dependent manner. Both the MMP-9 concentration in the supernatant and MMP-9 mRNA expression were reduced post intervention with rosiglitazone in both groups. The TIMP-1 mRNA expression and concentration in supernatant were not affected by rosiglitazone in both groups. Rosiglitazone induced significant downregulation of NF-kappaB P65 expression in both groups. CONCLUSION: Rosiglitazone intervention may downregulate MMP-9 expression by upregulating PPAR-gamma expression, and by downregulating NF-kappaB expression in MDMs isolated from patients with ACS.


Assuntos
Síndrome Coronariana Aguda/sangue , Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Tiazolidinedionas/farmacologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Vasodilatadores/farmacologia , Idoso , Estudos de Casos e Controles , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , PPAR gama/agonistas , Rosiglitazona , Fator de Transcrição RelA/metabolismo
11.
J Biol Chem ; 281(28): 19489-500, 2006 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-16682412

RESUMO

DNA CpG methylation can cooperate with histone H3 lysine 9 (H3-K9) methylation in heterochromatin formation and gene silencing. Trimethylation of H3-K9 by the recently identified euchromatic histone methyltransferase SETDB1/ESET may be responsible for transcriptional repression of certain promoters. Here, we show that SETDB1 associates with endogenous DNA methyltransferase activity. SETDB1 interacts with the de novo DNA methyltransferases DNMT3A and DNMT3B but not with the maintenance methyltransferase DNMT1. The interaction of SETDB1 with DNMT3A was further characterized and confirmed by in vivo and in vitro interaction studies. A direct interaction of the two proteins occurs through the N terminus of SETDB1 and the plant homeodomain of DNMT3A. Co-expression of SETDB1 and DNMT3A was essential for repression of reporter gene expression in a Gal4-based tethering assay and resulted in their recruitment to the artificial promoter. We further demonstrate that the CpG-methylated promoters of the endogenous p53BP2 gene in HeLa cells and the RASSF1A gene in MDA-MB-231 cells are simultaneously occupied by both SETDB1 and DNMT3A proteins, which provides evidence for SETDB1 being at least partly responsible for H3-K9 trimethylation at the promoter of RASSF1A, a gene frequently silenced in human cancers. In summary, our data demonstrate the direct physical interaction and functional connection between the H3-K9 trimethylase SETDB1 and the DNA methyltransferase DNMT3A and thus contribute to a better understanding of the complexity of the self-reinforcing heterochromatin machinery operating at silenced promoters.


Assuntos
DNA (Citosina-5-)-Metiltransferases/fisiologia , Neoplasias/metabolismo , Regiões Promotoras Genéticas , Proteínas Metiltransferases/fisiologia , Animais , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Ilhas de CpG , Metilação de DNA , DNA Metiltransferase 3A , Inativação Gênica , Células HeLa , Heterocromatina/metabolismo , Histona-Lisina N-Metiltransferase , Humanos , Proteínas Supressoras de Tumor/metabolismo
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