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1.
BMC Neurol ; 21(1): 221, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107910

RESUMO

BACKGROUND: Presentation with massive systemic embolization as the initial manifestation of occult malignancy is infrequent. The standard management of cancer-related arterial thromboembolism has not yet been established. CASE PRESENTATION: We described a case of Trousseau's syndrome resulting in acute ischemic stroke concomitant with multiple embolizations in the spleen and kidney during oral administration of dabigatran for pulmonary embolism preceding the diagnosis of a malignant tumor. A cancer-related hypercoagulable state was suspected because the patient was admitted to the neurology department due to acute ischemic stroke with three territory infarcts on diffusion-weighted imaging (DWI) in the absence of identifiable conventional risk factors and brain vessel narrowing. The patient was subsequently diagnosed with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) (stage IV) with pleural metastasis. Administration of low-molecular-weight heparin followed by long-term dabigatran under effective cancer therapy comprising gefitinib and subsequent chemotherapy did not cause stroke relapse during the 1-year follow-up. CONCLUSIONS: This case suggests that cancer-related hypercoagulability should be considered an important etiology for stroke patients who develop unexplained disseminated acute cerebral infarction without conventional stroke risk factors, especially concomitant with multiple organ embolization. Novel oral anticoagulants may be an alternative therapy for the long-term management of cancer-related arterial thromboembolism under effective cancer therapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Acidente Vascular Cerebral/etiologia , Anticoagulantes/uso terapêutico , Isquemia Encefálica/etiologia , Carcinoma Pulmonar de Células não Pequenas/complicações , Imagem de Difusão por Ressonância Magnética , Embolia/etiologia , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Pulmonares/complicações , Pessoa de Meia-Idade , Fatores de Risco
2.
Neuroimmunomodulation ; 26(5): 217-233, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31665717

RESUMO

OBJECTIVES: Cortical neuron-released exosomes have been demonstrated to block inflammasome activation in the central nervous system. This study aimed to investigate whether cortical neuron-released exosomal microRNA-181c-3p (miR-181c-3p) affected ischemic brain injury (IBI). METHODS: An IBI rat model was established by middle cerebral artery occlusion (MCAO). Astrocytes collected from rats were exposed to exosomes derived from cortical neurons to investigate the effect of exosomes on chemokine (C-X-C motif) ligand 1 (CXCL1) expression and inflammatory response. Then, ectopic expression was induced in astrocytes treated with oxygen and glucose deprivation (OGD). RESULTS: CXCL1 was identified to be an upregulated gene in IBI by microarray-based gene expression profiling. Additionally, upregulation of CXCL1 and promoted inflammatory response was also found in MCAO rats. miR-181c-3p was downregulated in OGD-treated cortical neurons and exosomes derived from OGD-treated cortical neurons. Exosomes derived from OGD-treated cortical neurons decreased the expression of CXCL1 and inflammatory factors in astrocytes, and exosomes delivered miR-181c-3p to decrease CXCL1 expression in astrocytes. CXCL1 was a target gene of miR-181c-3p. Delivery with miR-181c-3p mimic and siRNA against CXCL1 (si-CXCL1) was shown to inhibit inflammation in astrocytes by downregulating CXCL1. CONCLUSION: Collectively, exosomal miR-181c-3p derived from cortical neurons exerts protective effects on neuroinflammation in astrocytes via downregulation of CXCL1 in an IBI rat model.


Assuntos
Astrócitos/metabolismo , Quimiocina CXCL1/metabolismo , Exossomos/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Inflamação/metabolismo , MicroRNAs/metabolismo , Neurônios/metabolismo , Animais , Isquemia Encefálica/genética , Isquemia Encefálica/imunologia , Isquemia Encefálica/metabolismo , Hipóxia Celular/imunologia , Córtex Cerebral/citologia , Quimiocina CXCL1/genética , Quimiocina CXCL1/imunologia , Modelos Animais de Doenças , Regulação para Baixo , Exossomos/imunologia , Glucose/deficiência , Glucose/metabolismo , Técnicas In Vitro , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/imunologia , Inflamação/genética , Inflamação/imunologia , Masculino , MicroRNAs/genética , MicroRNAs/imunologia , Ratos , Transcriptoma , Regulação para Cima
3.
Neurochem Res ; 41(9): 2300-10, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27180190

RESUMO

Aliskiren (ALK), a pharmacological renin inhibitor, is an effective antihypertensive drug and has potent anti-apoptotic activity, but it is currently unknown whether ALK is able to attenuate brain damage caused by acute cerebral ischemia independent of its blood pressure-lowering effects. This study aimed to investigate the role of ALK and its potential mechanism in cerebral ischemia. C57/BL6 mice were subjected to transient middle cerebral artery occlusion (tMCAO) and treated for 5 days with Vehicle or ALK (10 or 25 mg/kg per day via intragastric administration), whereas Sham-operated animals served as controls. Treatment with ALK significantly improved neurological deficits, infarct volume, brain water content and Nissl bodies after stroke (P < 0.05), which did not affect systemic blood pressure. Furthermore, the protection of ALK was also related to decreased levels of apoptosis in mice by enhanced activation of phosphatidylinositol 3-kinase (PI3K)/AKT pathway, increased level of Bcl-2 and reduced Bax expression (P < 0.05). In addition, ALK's effects were reversed by PI3K inhibitors LY294002 (P < 0.05). Our data indicated that ALK protected the brain from reperfusion injuries without affecting blood pressure, and this effect may be through PI3K/AKT signaling pathway.


Assuntos
Amidas/farmacologia , Isquemia Encefálica/prevenção & controle , Fumaratos/farmacologia , Fármacos Neuroprotetores/farmacologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismo , Animais , Apoptose/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Acidente Vascular Cerebral/prevenção & controle , Regulação para Cima/efeitos dos fármacos
4.
Neurochem Res ; 39(1): 97-106, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24248858

RESUMO

Inflammatory damage plays an important role in cerebral ischemic pathogenesis and represents a new target for treatment of stroke. Shikonin has gained attention for its prominent anti-inflammatory property, but up to now little is known about shikonin treatment in acute ischemic stroke. The aim of this study was to evaluate the potential neuroprotective role of shikonin in cerebral ischemic injury, and investigate whether shikonin modulated inflammatory responses after stroke. Focal cerebral ischemia in male ICR mice was induced by transient middle cerebral artery occlusion. Shikonin (10 and 25 mg/kg) was administered by gavage once a day for 3 days before surgery and another dosage after operation. Neurological deficit, infarct volume, brain edema, blood-brain barrier (BBB) dysfunction, and inflammatory mediators were evaluated at 24 and 72 h after stroke. Compared with vehicle group, 25 mg/kg shikonin significantly improved neurological deficit, decreased infarct volume and edema both at 24 and 72 h after transient ischemic stroke, our data also showed that shikonin inhibited the pro-inflammatory mediators, including TLR4, TNF-α, NF-κB, and phosphorylation of p38MAPK in ischemic cortex. In addition, shikonin effectively alleviated brain leakage of Evans blue, up-regulated claudin-5 expression, and inhibited the over-expressed MMP-9 in ischemic brain. These results suggested that shikonin effectively protected brain against ischemic damage by regulating inflammatory responses and ameliorating BBB permeability.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Isquemia Encefálica/patologia , Naftoquinonas/uso terapêutico , Receptor 4 Toll-Like/biossíntese , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Claudina-5/biossíntese , Regulação para Baixo , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Metaloproteinase 9 da Matriz/biossíntese , Camundongos , Camundongos Endogâmicos ICR , NF-kappa B/biossíntese , Fármacos Neuroprotetores/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Fator de Necrose Tumoral alfa/biossíntese , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Cell Death Discov ; 10(1): 300, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914581

RESUMO

Neuroinflammation caused by microglia and other immune cells plays pivotal role in cerebral ischemia/reperfusion injury and recovery. Modulating microglial polarization or Treg/Th17 balance from pro-inflammatory phenotype to anti-inflammatory phenotype are promising strategies for the treatment of cerebral ischemia. Curcumol has potential to fight against oxidative stress and inflammation, but whether it has protective effect in cerebral ischemia is uncertain. In the present study, cerebral ischemia was induced in C57BL/6 mice via middle cerebral artery occlusion (MCAO). MCAO mice were treated with curcumol for 7 days, then post-stroke ischemic injury, neurological deficits, microglial polarization and brain leukocyte infiltration were evaluated by TTC staining, behavioural tests, flow cytometry, western blot and immunofluorescence. We found that poststroke administration of curcumol reduced infarct volume, attenuated neuronal damage and inflammation, and improved motor function recovery of MCAO mice. Curcumol skewed microglial polarization toward anti-inflammatory phenotype in MCAO mice in vivo or after oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. In addition, curcumol reduced local T cell infiltration in ischemic brain of MCAO mice and impaired Treg/Th17 balance. Curcumol inhibited ROS production and regulated Nrf2/HO-1 and NF-κB signaling in microglia. Finally, inhibiting Nrf2/HO-1 signaling or activating NF-κB signaling abrogated the influence of curcumol on microglial polarization. In conclusion, curcumol treatment reduced brain damage and neuroinflammation via modulating anti-inflammatory microglial polarization and Treg/Th17 balance through Nrf2/HO-1 and NF-κB signaling. Curcumol might be a promising treatment strategy for stroke patients.

6.
Cancers (Basel) ; 14(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36230774

RESUMO

FOXC2 is a forkhead family transcription factor that plays a critical role in specifying mesenchymal cell fate during embryogenesis. FOXC2 expression is associated with increased metastasis and poor survival in various solid malignancies. Using in vitro and in vivo assays in mouse ovarian cancer cell lines, we confirmed the previously reported mechanisms by which FOXC2 could promote cancer growth, metastasis, and drug resistance, including epithelial-mesenchymal transition, stem cell-like differentiation, and resistance to anoikis. In addition, we showed that FOXC2 expression is associated with vasculogenic mimicry in mouse and human ovarian cancers. FOXC2 overexpression increased the ability of human ovarian cancer cells to form vascular-like structures in vitro, while inhibition of FOXC2 had the opposite effect. Thus, we present a novel mechanism by which FOXC2 might contribute to cancer aggressiveness and poor patient survival.

7.
J Oncol ; 2021: 8142155, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34966428

RESUMO

According to the most current cancer impact statistics, third most commonly diagnosed cancer worldwide is colorectal cancer. Colon cancer, in addition to its physical symptoms, has been linked to mental health issues in patients, according to the study. Dealing with colorectal cancer drug chemotherapy may lead to depression and anxiety in some people. Others are affected by the physical and mental condition of undergoing many therapies at the same time. Throughout the process of diagnosis, a large number of colorectal cancer patients report clinically relevant degrees as well as a decline in overall mental wellness. In the majority of cases, colon cancer patients are cured following therapy, but those who have survived the disease confront a medical range, physical, and challenges in society, for a variety of mental and physical problems such as anxiety and depression. First, meditation therapy is to urge patients to address their issues and feelings instead of dismissing them, but in the dispassionate and unbiased manner that defines the attentive state. Both the patient and the treating professional may benefit from this treatment method, since it appears to be a very effective therapeutic strategy. After colorectal cancer treatment, in studies, it has been demonstrated that ACT improves mental health, and Internet search engines such as Web of Science and Google Scholar as well as Dialnet were utilized to conduct a systematic literature There were 19 articles that fit the criteria. This includes a discussion of the ACT's philosophical and theoretical basis, as well as the treatment itself. On the other hand, the study on ACT for enhancing mental health and quality of life is examined. Several of the available trials had serious flaws, making it impossible to establish reliable conclusions about the effectiveness of ACT for improving mental health and quality of life. The study determined that there is only a small amount of data supporting the use of ACT for improving mental health. The aim of this study is the application of the nursing model on improving the mental health of the colorectal patients. In addition, the limits of the current empirical state of ACT are acknowledged, and the importance of further research is highlighted.

8.
Int J Cancer ; 123(9): 2041-7, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18726901

RESUMO

Hepsin is a serine protease that is widely expressed in different tissues and cell types, most prominently in the normal liver and kidney. Overexpression of hepsin has been associated with prostate cancers, ovarian cancers and renal cell carcinomas. The physiological functions of hepsin in normal tissues and tumors are poorly understood. To gain insight into its function in ovarian cancer, we analyzed the expression and subcellular localization of hepsin protein in ovarian cancer cell lines and tumors. We showed that the membrane-associated hepsin protein is present at desmosomal junctions, where it colocalizes with its putative proteolytic substrate hepatocyte growth factor. Consistent with the growing evidence that desmosomal junctions and their constituents play a role in cancer progression, we demonstrated that overexpression of hepsin promotes ovarian tumor growth in a mouse model. The ability of ectopic hepsin to induce tumor growth in mice is abrogated by the mutation of 3 critical residues in the catalytic domain, thus implicating the enzymatic activity of hepsin in promoting tumor progression.


Assuntos
Desmossomos/química , Neoplasias Ovarianas/patologia , Serina Endopeptidases/fisiologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fator de Crescimento de Hepatócito/análise , Fator de Crescimento de Hepatócito/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Serina Endopeptidases/análise
10.
Neural Regen Res ; 13(12): 2119-2128, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30323140

RESUMO

Rosmarinic acid (RA) can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in CD-1 mice (Beijing Vital River Laboratory Animal Technology, Beijing, China) by occluding the right middle cerebral artery for 1 hour and allowing reperfusion for 24 hours. After intraperitoneally injecting model mice with 10, 20, or 40 mg/kg RA, functional neurological deficits were evaluated using modified Longa scores. Subsequently, cerebral infarct volume was measured using TTC staining and ischemic brain tissue was examined for cell apoptosis with TUNEL staining. Superoxide dismutase activity and malondialdehyde levels were measured by spectrophometry. Expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), Bcl-2, Bax, Akt, and phospho-Ser473 Akt proteins in ischemic brain tissue was detected by western blot, while mRNA levels of Nrf2, HO-1, Bcl-2, and Bax were analyzed using real time quantitative PCR. In addition, HO-1 enzyme activity was measured spectrophotometrically. RA (20 and 40 mg/kg) greatly improved neurological function, reduced infarct volume, decreased cell apoptosis, upregulated Bcl-2 protein and mRNA expression, downregulated Bax protein and mRNA expression, increased HO-1 and Nrf2 protein and mRNA expression, increased superoxide dismutase activity, and decreased malondialdehyde levels in ischemic brain tissue of model mice. However, intraperitoneal injection of a HO-1 inhibitor (10 mg/kg zinc protoporphyrin IX) reversed the neuroprotective effects of RA on HO-1 enzyme activity and Bcl-2 and Bax protein expression. The PI3K/Akt signaling pathway inhibitor LY294002 (10 mM) inhibited Akt phosphorylation, as well as Nrf2 and HO-1 expression. Our findings suggest that RA has anti-oxidative and anti-apoptotic properties that protect against ischemic stroke by a mechanism involving upregulation of Nrf2 and HO-1 expression via the PI3K/Akt signaling pathway.

11.
Peptides ; 105: 58-65, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29800588

RESUMO

Endothelial progenitor cells (EPCs) are of great importance in the process of endogenous blood vessel repair to maintain endothelial integrity and have been applied in a wide range of models of ischemic diseases. MicroRNAs represent a class of non-protein coding endogenous RNAs with 19-24 nucleotides in length and serve an important role in multiple physiological and pathological processes, including angiogenesis. It has been reported that miR-503 reduces angiogenesis in tumorigenesis. However, to our knowledge, the precise role of miR-503 in the regulation of EPCs remains unclear. In the current study, we found that the expression of miR-503 was decreased in mouse bone marrow derived EPCs under the hypoxic condition. Importantly, upregulation of miR-503 suppressed the proliferation, migration and capillary-like tube formation of EPCs induced by hypoxia. Furthermore, a dual luciferase reporter assay showed that Apelin, an endogenous ligand of the G protein-coupled receptor APJ, was a direct target of miR-503 and overexpression of miR-503 significantly inhibited the protein level of Apelin in EPCs. Moreover, hypoxia treatment enhanced the expression of Apelin in EPCs. Meanwhile ectopic expression of Apelin promoted cellular proliferation, migration and tube formation of EPCs in vitro. In summary, our results indicate that miR-503 regulates proliferation, migration and angiogenesis of EPCs by targeting Apelin.


Assuntos
Apelina/genética , Proliferação de Células/genética , MicroRNAs/genética , Neovascularização Patológica/genética , Animais , Hipóxia Celular/genética , Movimento Celular/genética , Células Progenitoras Endoteliais/metabolismo , Células Progenitoras Endoteliais/patologia , Regulação da Expressão Gênica , Humanos , Camundongos , Neovascularização Patológica/patologia
12.
Int J Oncol ; 28(3): 715-22, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16465377

RESUMO

Mutations of beta-catenin have been identified in the majority of pediatric hepatic malignancies, including hepatoblastoma (HB) and hepatocellular carcinoma (HCC), suggesting its important contribution in hepatic tumorigenesis in this age group. However, the role of beta-catenin/canonical Wnt signaling pathway in the neoplastic growth of cancer cells has not been directly studied. To address beta-catenin's capability in maintaining the malignant phenotype in established pediatric HB and HCC cell lines, HuH-6 and HepG2, harboring mutated and overexpressed beta-catenin, we carried out a series of in vitro analyses through a transfection of short interfering RNAs (siRNAs) to generate a loss-of-function model. HuH-7, another HB cell line derived from a pediatric patient without a stabilizing mutation was used for comparison. RNA interference successfully manipulated the degradation of overexpressed beta-catenin. In all cell lines, beta-catenin mRNA was suppressed by 80-90% after 48 h of transfection, and a reduction of its protein expression was demonstrated. In HuH-6 and HepG2, the pre-existing beta-catenin nuclear accumulation disappeared and reductions of beta-catenin downstream target genes, c-myc and cyclinD1, were also evidenced after the treatment. The in vitro proliferation of both cell lines was transiently inhibited. In contrast, the suppression of beta-catenin in HuH-7 did not lead to a significant change in the expression of target genes or cellular proliferation. Our data indicate that beta-catenin can be considered a specific target for gene therapy in pediatric hepatic tumors with mutations and overexpression of this gene.


Assuntos
Proliferação de Células , Interferência de RNA , beta Catenina/genética , Apoptose , Western Blotting , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Criança , Análise Mutacional de DNA , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Mutação , RNA Interferente Pequeno/genética , Transfecção , beta Catenina/metabolismo
13.
Peptides ; 75: 96-100, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26631263

RESUMO

Apelin has been proved to be protective against apoptosis induced by ischemic reperfusion. However, mechanisms whereby apelin produces neuroprotection remain to be elucidated. AMP-activated protein kinase (AMPK) is a master energy sensor that monitors levels of key energy metabolites. It is activated via AMPKαThr172 phosphorylation during cerebral ischemia and appears to be neuroprotective. In this study, we investigated the effect of apelin on AMPKα and tested whether apelin protecting against apoptosis was associated with AMPK signals. Focal transient cerebral ischemia/reperfusion (I/R) model in male ICR mice was induced by 60 min of ischemia followed by reperfusion. Apelin-13 was injected intracerebroventricularly 15 min before reperfusion. AMPK inhibitor, compound C, was injected to mice intraperitoneally at the onset of ischemia. In experiment 1, the effect of apelin-13 on AMPKα was measured. In experiment 2, the relevance of AMPKα and apelin-13' effect on apoptosis was measured. Data showed that apelin-13 significantly increased AMPKα phosphorylation level after cerebral I/R. Apelin-13, with the co-administration of saline, reduced apoptosis cells, down-regulated Bax and cleaved-caspase3 and up-regulated Bcl2. However, with the co-administration of compound C, apelin-13 was inefficient in affecting apoptosis and Bax, Bcl2 and cleaved-caspase3. The study provided the evidence that apelin-13 up-regulated AMPKα phosphorylation level in cerebral ischemia insults and AMPK signals participated in the mechanism of apelin-mediated neuroprotection.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Ativação Enzimática , Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/patologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Masculino , Camundongos Endogâmicos ICR , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Proteína X Associada a bcl-2/metabolismo
14.
Oncol Rep ; 10(6): 1943-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14534723

RESUMO

The Wnt signaling pathway is conserved in various species from worms to mammals, and plays critical roles in development, cellular proliferation and differentiation. As part of Wnt signal transduction, the function of the Axin complex is inhibited, leading to the accumulation of beta-catenin protein. Axin gene mutations have been detected in several kinds of human cancers. In this study, we investigated Axin gene alterations in a series of 58 pediatric neoplasms including neuroblastomas, teratomas, rhabdomyosarcomas. Forty-eight non-tumor tissues were used as a control series to compare gene alterations and their frequencies between tumors and normal tissues. The whole coding region of the Axin gene was examined by PCR-SSCP method using 24 sets of the primers. Samples revealing aberrant band patterns were subjected to direct sequencing analysis. In total, we identified six variants in the exons and four intronic nucleotide substitutions in the tumor series. Similar sequence variants except a rare sequence variant at codon 98 (CCG right curved arrow CTG) were observed in the control series and these were regarded as non-pathogenetic polymorphisms. Our results indicated that a tumor-associated mutation of the Axin gene is generally a rare event in our series of pediatric neoplasms.


Assuntos
Mutação , Neoplasias/genética , Proteínas Repressoras/genética , Proteína Axina , Sequência de Bases , Divisão Celular , Linhagem Celular Tumoral , Criança , Códon , Proteínas do Citoesqueleto/metabolismo , Éxons , Humanos , Íntrons , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo Genético , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA , Transdução de Sinais , Transativadores/metabolismo , beta Catenina
15.
Oncol Rep ; 12(6): 1269-72, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15547749

RESUMO

BRAF (v-raf murine sarcoma viral oncogene homolog B1) activating mutations in a high proportion of melanomas and in a small fraction of other cancers have been recently reported. All the presented mutations of BRAF are located in exons 11 and 15, and the hotspot mutation at codon 599 accounts for 87% of BRAF mutations. Because the mutational status is unclear in pediatric solid neoplasms, we screened BRAF mutations comprehensively in our tumor series presented in childhood. Two pairs of primers were designed to amplify exons 11 and exon 15, respectively, and 181 tumor samples (65 neuroblastomas, 23 Wilms tumors, 19 hepatoblastomas, 16 teratomas, 17 rhabdomyosarcomas, 13 ganglioneuromas, etc.) were investigated by PCR-SSCP method. On agarose gel electrophoresis, amplified PCR fragments showed no size-altered changes in exons 11 and 15, and SSCP analysis revealed uniform band patterns in both exons. Subsequent direct sequencing of selected 10 samples confirmed only normal sequences without any nucleotide substitutions. The current study represents the first genetic analysis of the BRAF gene in pediatric solid tumors. Our data suggest that mutations of BRAF gene as a mechanism of tumorigenesis is unlikely to be associated with most childhood neoplasms.


Assuntos
Neoplasias/genética , Proteínas Proto-Oncogênicas B-raf/genética , Criança , Análise Mutacional de DNA , Humanos , Mutação , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples
16.
Int J Mol Med ; 9(4): 377-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11891531

RESUMO

The Wnt signaling pathway is essential for embryonic development and can be involved in tumorigenesis when aberrantly activated. In a subset of Wilms' tumors, beta-catenin mutations have been identified, and this suggested that abnormally activated Wnt signaling may contribute to tumorigenesis of this tumor. Because Axin has been recognized as a main component of Wnt signaling, and its mutations were reported in several types of malignancies, we analyzed Axin gene mutations in 22 pediatric renal tumors. Twenty-four sets of the primers, which cover the whole coding region of the Axin gene, were used for PCR-SSCP analyses. Samples revealing aberrant band patterns were further analyzed for sequencing. We have only identified 4 silent mutations in the coding region and 3 intronic polymorphisms in Axin gene, accordingly no pathogenetic gene mutations were detected. Our results indicated that mutations of Axin gene as a mechanism of tumorigenesis are not associated with pediatric renal tumors including Wilms' tumors.


Assuntos
Neoplasias Renais/genética , Mutação , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras , Proteínas de Peixe-Zebra , Proteína Axina , Criança , Pré-Escolar , Humanos , Neoplasias Renais/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais/genética , Proteínas Wnt
17.
Int J Mol Med ; 10(4): 395-9, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12239584

RESUMO

Wilms' tumor (WT) is the most common childhood renal malignancy. Although several genetic loci such as the WT1 gene have been known to relate to the biology of WT, the cause of the tumor is complex and the implicated molecular pathways are largely unknown. The beta-catenin gene encodes a protein playing an important role in the Wnt signaling pathway, and its mutations that abrogate specific serine/threonine phosphorylation sites and express oncogenic effect have been found in a variety of tumors. Implication of beta-catenin mutations in WT was investigated in 24 tumors collected from 20 WT patients. One patient had a total of five multiple tumors simultaneously in the bilateral kidneys. Exon 3 and its flanking regions encompassing mutational hot spots of the gene were examined by PCR-based methods. Samples indicating to harbor mutations were further analyzed by sequencing. Six tumors (6/24, 25%) from 4 patients (4/20, 20%) were confirmed to have mutations in heterozygous status. All the mutations, including five different types, were uniformly observed at codon 45 (Ser). Three mutations, Ser45Phe (TCT --> TTT), Ser45Tyr (TCT --> TAT), and Delta45 (deletion of TCT), were found in 3 of 19 unilateral WTs. Other three mutations were detected in three of five multiple tumors developed in the bilateral WT patient; a mutation of Delta45 in one of two tumors in the right kidney, and Ser45Cys (TCT --> TGT) and Ser45Pro (TCT --> CCT) in two of three tumors in the left kidney. Frequent beta-catenin mutations preferentially occurring at codon 45 most likely indicate special importance of this codon for the development of WT and existence of an underlying mechanism causing such a tissue-specific mutational pattern.


Assuntos
Proteínas do Citoesqueleto/genética , Mutação , Transativadores/genética , Tumor de Wilms/genética , Núcleo Celular/metabolismo , Pré-Escolar , Proteínas do Citoesqueleto/metabolismo , Humanos , Imuno-Histoquímica , Lactente , Transativadores/metabolismo , beta Catenina
18.
Int J Mol Med ; 11(4): 461-4, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12632098

RESUMO

Beta-catenin serves not only as a structural component of the E-cadherin-mediated cell-cell adhesion system, but also as a signaling molecule of the Wnt/wingless pathway. Mutations of beta-catenin and aberrant expression of its protein have been identified in a number of different types of human malignancies. To determine the role of beta-catenin in solid and cystic tumor (SCT) of the pancreas, a rare neoplasm usually observed in young females, we examined three primary tumors and one corresponding liver metastatic tumor presented in pediatric patients. Single strand conformation polymorphism and neucleotide sequencing analysis confirmed a TCT right curved arrow TTT somatic mutation at codon 37 changing serine to phenylalanine in one of the primary tumors and its corresponding metastatic tumor. Immunohistochemical analysis displayed abnormally strong nuclear and widespread cytoplasmic expression of beta-catenin in these tumors with the mutation. Our observations suggest that, in some SCTs of the pancreas presented in the pediatric age group, mutated beta-catenin has an important oncogenic effect.


Assuntos
Proteínas do Citoesqueleto/genética , Metástase Neoplásica , Neoplasias Pancreáticas/metabolismo , Transativadores/genética , Criança , Proteínas do Citoesqueleto/metabolismo , Análise Mutacional de DNA , Feminino , Humanos , Imuno-Histoquímica , Masculino , Transativadores/metabolismo , beta Catenina
19.
Hepatol Res ; 25(2): 174-179, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12644054

RESUMO

The Wnt signaling pathway plays critical roles in the embryonic development and tumorigenesis. As a part of the Wnt signal transduction, the function of Axin complex is inhibited, leading to accumulation of beta-catenin. In hepatoblastomas, loss of APC (adenomatous polyposis coli) function or activation of beta-catenin that are the other two components involving in Wnt signaling has been demonstrated. Because hepatoblastoma shows immunohistochemical positivity of beta-catenin more often than its mutation frequency, we analyzed the Axin gene as a candidate to lead beta-catenin accumulation in hepatoblastoma. The coding region of the Axin gene was examined by PCR-SSCP using 24 sets of the primers in 22 hepatoblastomas and some paired normal tissues. Samples revealing aberrant band patterns were subjected to direct sequencing analysis. We identified totally eight variants in the exons and four intronic nucleotide substitutions. Seven variants in the exons were silent mutations, however, the remaining variant at codon 95 (ACG-->ATG) found in one hepatoblastoma predicted to result in an amino acid change from threonine to methionine. The paired peripheral blood DNAs from this patient also showed the same change; we suggested that it was a germline mutation of Axin gene. Our results suggest that mutation of the Axin gene may have a tumorigenic function in a subset of childhood hepatoblastomas.

20.
J Gerontol A Biol Sci Med Sci ; 68(10): 1181-92, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23525481

RESUMO

Myostatin is a highly conserved member of the transforming growth factor-ß ligand family known to regulate muscle growth via activation of activin receptors. A fusion protein consisting of the extracellular ligand-binding domain of activin type IIB receptor with the Fc portion of human immunoglobulin G (ActRIIB-Fc) was used to inhibit signaling through this pathway. Here, we study the effects of this fusion protein in adult, 18-month-old, and orchidectomized mice. Significant muscle growth and enhanced muscle function were observed in adult mice treated for 3 days with ActRIIB-Fc. The ActRIIB-Fc-treated mice had enhanced fast fatigable muscle function, with only minor enhancement of fatigue-resistant fiber function. The ActRIIB-Fc-treated 18-month-old mice and orchidectomized mice showed significantly improved muscle function. Treatment with ActRIIB-Fc also increased bone mineral density and serum levels of a marker of bone formation. These observations highlight the potential of targeting ActRIIB receptor to treat age-related and hypogonadism-associated musculoskeletal degeneration.


Assuntos
Receptores de Activinas Tipo II/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Densidade Óssea/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Receptores de Activinas Tipo II/metabolismo , Animais , Biomarcadores/sangue , Densidade Óssea/fisiologia , Linhagem Celular , Células HEK293 , Humanos , Fragmentos Fc das Imunoglobulinas/metabolismo , Fragmentos Fc das Imunoglobulinas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Contração Muscular/fisiologia , Força Muscular/efeitos dos fármacos , Força Muscular/fisiologia , Miostatina/metabolismo , Orquiectomia , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Sarcopenia/tratamento farmacológico , Sarcopenia/patologia , Sarcopenia/fisiopatologia
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