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1.
Mol Cancer Res ; 12(3): 408-420, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24319068

RESUMO

UNLABELLED: Breast cancers with HER2 overexpression are sensitive to drugs targeting the receptor or its kinase activity. HER2-targeting drugs are initially effective against HER2-positive breast cancer, but resistance inevitably occurs. We previously found that NF-κB is hyperactivated in a subset of HER2-positive breast cancer cells and tissue specimens. In this study, we report that constitutively active NF-κB rendered HER2-positive cancer cells resistant to anti-HER2 drugs and cells selected for lapatinib resistance upregulated NF-κB. In both circumstances, cells were antiapoptotic and grew rapidly as xenografts. Lapatinib-resistant cells were refractory to HER2 and NF-κB inhibitors alone but were sensitive to their combination, suggesting a novel therapeutic strategy. A subset of NF-κB-responsive genes was overexpressed in HER2-positive and triple-negative breast cancers, and patients with this NF-κB signature had poor clinical outcome. Anti-HER2 drug resistance may be a consequence of NF-κB activation, and selection for resistance results in NF-κB activation, suggesting that this transcription factor is central to oncogenesis and drug resistance. Clinically, the combined targeting of HER2 and NF-κB suggests a potential treatment paradigm for patients who relapse after anti-HER2 therapy. Patients with these cancers may be treated by simultaneously suppressing HER2 signaling and NF-κB activation. IMPLICATIONS: The combination of an inhibitor of IκB kinase (IKK) inhibitor and anti-HER2 drugs may be a novel treatment strategy for drug-resistant human breast cancers.


Assuntos
Neoplasias da Mama/patologia , NF-kappa B/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/fisiologia , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Lapatinib , Camundongos , Camundongos Nus , NF-kappa B/genética , Quinazolinas/farmacologia , Receptor ErbB-2/genética , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Cell Biochem Biophys ; 67(2): 281-6, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21960420

RESUMO

Circumstantial evidence frequently implicates oxygen-derived free radicals and oxidative stress as mediators of myocardial ischemia/reperfusion (I/R) injury. Therefore, external supplementation of natural antioxidants plays a main role as cardioprotective compounds. This study was designed to evaluate the cardioprotective effect of VitaePro (70 mg/kg body weight, 21 days), a novel antioxidant mix of astaxanthin, lutein and zeaxanthin in a rat ex vivo model of ischemia/reperfusion injury. The cardioprotective effect of VitaePro was also compared with vitamin E (70 mg/kg body weight, 21 days) treatment. Rats were randomized into control I/R (CIR), VitaePro I/R (VPIR) and Vitamin E I/R (VEIR). After 21 days of oral treatment, isolated hearts from each group were subjected to 30 min of ischemia followed by 2 h of reperfusion. In the VPIR group compared to CIR and VEIR groups at 2 h of reperfusion, increased left ventricular functional recovery, such as left ventricular developed pressure (92.7 ± 0.7 vs. 85.3 ± 0.3 and 89.4 ± 1.2 mm Hg), dp/dt max (2518.7 ± 77.9 vs. 1962.5 ± 24 and 2255.7 ± 126.6 mm Hg/s), and aortic flow (21.5 ± 1.36 vs. 4.4 ± 0.6 and 13.2 ± 1.02 ml/min) were observed. The infarct size (27.68 ± 1.7 vs. 45.4 ± 1.8 and 35.4 ± 0.6%), apoptotic cardiomyocytes (61.7 ± 10.6 vs. 194.1 ± 14.8 and 118.7 ± 15.4 counts/100 HPF) and thiobarbituric acid reactive substances levels (80 ± 3 vs. 127 ± 5 and 103 ± 2 nM/mg tissue) also were decreased in VPIR group when compared to CIR and VEIR. As evidenced by the data, administration of vitamin E offered substantial cardioprotection to I/R injury, but VitaePro enhanced cardioprotection significantly more than vitamin E treatment. Taken in concert, the results of this study suggests that the oral ingestion of VitaePro protects myocardium from ischemia/reperfusion injury by decreasing oxidative stress and apoptosis, which may be of therapeutic benefit in the treatment of cardiovascular complications. However, further in vivo animal and human intervention studies are warranted before establishing any recommendations about usage of VitaePro for human cardiovascular complications.


Assuntos
Antioxidantes/farmacologia , Cardiotônicos/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Combinação de Medicamentos , Coração/efeitos dos fármacos , Coração/fisiopatologia , Luteína/farmacologia , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Xantofilas/farmacologia , Zeaxantinas
3.
Toxicol Mech Methods ; 22(5): 347-58, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22424133

RESUMO

Prolyl hydroxylases belong to the family of iron- and 2-oxoglutamate-dependent dioxygenase enzyme. Several distinct prolyl hydroxylases have been identified. The hypoxia-inducible factor (HIF) prolyl hydroxylase termed prolyl hydroxylase domain (PHD) enzymes play an important role in oxygen regulation in the physiological network. There are three isoforms that have been identified: PHD1, PHD2 and PHD3. Deletion of PHD enzymes result in stabilization of HIFs and offers potential treatment options for many ischemic disorders such as peripheral arterial occlusive disease, myocardial infarction, and stroke. All three isoforms are oxygen sensors that regulate the stability of HIFs. The degradation of HIF-1α is regulated by hydroxylation of the 402/504 proline residue by PHDs. Under hypoxic conditions, lack of oxygen causes hydroxylation to cease HIF-1α stabilization and subsequent translocation to the nucleus where it heterodimerizes with the constitutively expressed ß subunit. Binding of the HIF-heterodimer to specific DNA sequences, named hypoxia-responsive elements, triggers the transactivation of target genes. PHD regulation of HIF-1α-mediated cardioprotection has resulted in considerable interest in these molecules as potential therapeutic targets in cardiovascular and ischemic diseases. In recent years, attention has been directed towards identifying small molecule inhibitors of PHD. It is postulated that such inhibition might lead to a clinically useful strategy for protecting the myocardium against ischemia and reperfusion injury. Recently, it has been reported that the orally absorbed PHD inhibitor GSK360A can modulate HIF-1α signaling and protect the failing heart following myocardial infarction. Furthermore, PHD1 deletion has been found to have beneficial effects through an increase in tolerance to hypoxia of skeletal muscle by reprogramming basal metabolism. In the mouse liver, such deletion has resulted in protection against ischemia and reperfusion. As a result of these preliminary findings, PHDs is attracting increasing interest as potential therapeutic targets in a wide range of diseases.


Assuntos
Cardiotônicos/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Dioxigenases/fisiologia , Inibidores Enzimáticos/uso terapêutico , Proteínas Nucleares/fisiologia , Pró-Colágeno-Prolina Dioxigenase/fisiologia , Animais , Cardiotônicos/administração & dosagem , Doenças Cardiovasculares/enzimologia , Dioxigenases/antagonistas & inibidores , Dioxigenases/genética , Inibidores Enzimáticos/administração & dosagem , Regulação Enzimológica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Pró-Colágeno-Prolina Dioxigenase/antagonistas & inibidores , Pró-Colágeno-Prolina Dioxigenase/genética
4.
Antioxid Redox Signal ; 17(2): 327-39, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22404530

RESUMO

UNLABELLED: In living systems, the mechanisms of inheritance involving gene expression are operated by (i) the traditional model of genetics where the deoxyribonucleic acid (DNA) transcription and messenger ribonucleic acid stability are influenced by the DNA sequences and any aberrations in the primary DNA sequences and (ii) the epigenetic (above genetics) model in which the gene expression is regulated by mechanisms other than the changes in DNA sequences. The widely studied epigenetic alterations include DNA methylation, covalent modification of chromatin structure, state of histone acetylation, and involvement of microribonucleic acids. SIGNIFICANCE: Currently, the role of cellular epigenome in health and disease is rapidly emerging. Several factors are known to modulate the epigenome-regulated gene expression that is crucial in several pathophysiological states and diseases in animals and humans. Phytochemicals have occupied prominent roles in human diet and nutrition as protective antioxidants in prevention/protection against several disorders and diseases in humans. RECENT ADVANCES: However, it is beginning to surface that the phytochemical phenolic antioxidants such as polyphenols, flavonoids, and nonflavonoid phenols function as potent modulators of the mammalian epigenome-regulated gene expression through regulation of DNA methylation, histone acetylation, and histone deacetylation in experimental models. CRITICAL ISSUES AND FUTURE DIRECTIONS: The antioxidant or pro-oxidant actions and their involvement in the epigenome regulation by the phytochemical phenolic antioxidants should be at least established in the cellular models under normal and pathophysiological states. The current review discusses the mechanisms of modulation of the mammalian cellular epigenome by the phytochemical phenolic antioxidants with implications in human diseases.


Assuntos
Antioxidantes/farmacologia , Doença , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/genética , Epigenômica , Genoma/efeitos dos fármacos , Saúde , Animais , Genoma/genética , Humanos
5.
Toxicol Mech Methods ; 22(5): 330-5, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22394340

RESUMO

In recent years, diabetes and its associated complications have come to represent a major public health concern. It is a complex disease characterized by multiple metabolic derangements and is known to impair cardiac function by disrupting the balance between pro-oxidants and antioxidants at the cellular level. The subsequent generation of reactive oxygen species (ROS) and accompanying oxidative stress are hallmarks of the molecular mechanisms responsible for cardiovascular disease. Among several oxidative stress-mediated mechanisms that have been proposed, ROS-mediated oxidative stress has received the most attention. ROS have been shown to interact with proteins, lipids, and DNA, causing damage to the cellular macromolecules and subsequently, deterioration of cellular function. Induction of thioredoxin-1 (Trx1) gene expression has been demonstrated to protect the diabetic myocardium from dysfunction by reducing oxidative stress and enhancing the expression of heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF). The failure of antioxidants to consistently demonstrate clinical benefit necessitates further investigation of the role of oxidative stress in diabetes-mediated cardiovascular disease.


Assuntos
Cardiomiopatia Dilatada/etiologia , Cardiomiopatia Hipertrófica/etiologia , Cardiomiopatia Restritiva/etiologia , Cardiomiopatias Diabéticas/etiologia , Estresse Oxidativo , Animais , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Cardiomiopatia Dilatada/tratamento farmacológico , Cardiomiopatia Dilatada/imunologia , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Hipertrófica/tratamento farmacológico , Cardiomiopatia Hipertrófica/imunologia , Cardiomiopatia Hipertrófica/metabolismo , Cardiomiopatia Restritiva/tratamento farmacológico , Cardiomiopatia Restritiva/imunologia , Cardiomiopatia Restritiva/metabolismo , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/imunologia , Cardiomiopatias Diabéticas/metabolismo , Heme Oxigenase-1/biossíntese , Heme Oxigenase-1/genética , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/genética , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/genética
6.
Funct Integr Genomics ; 12(3): 501-14, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22038056

RESUMO

Several potential sources of reactive oxygen species (ROS) in cells exist. One source is NADPH oxidase, which is especially important for superoxide radical production. Nox2 is a primary regulatory subunit of NADPH oxidase. In the present study, we examined the role of ROS and NADPH oxidase in ischemic preconditioning (IP)-mediated cardioprotection by using Nox2(-/-) mice. Both wild-type (WT) and Nox2(-/-) mice were subjected to either 30 min of ischemia followed by 2 h of reperfusion (IR) or IP prior to 30 min ischemia and 2 h of reperfusion. Reduction in left ventricular developed pressure (60.1 versus 63 mmHg), dp/dt (max) (893 versus 1,027 mmHg/s), and aortic flow (0.9 versus 1.8 ml/min) was observed in Nox2(-/-)IPIR compared to WTIPIR along with increased infarct size (33% versus 22%) and apoptosis after 120 min of reperfusion. Differentially regulated genes were demonstrated by comparing gene expression in WTIPIR versus Nox2(-/-) IPIR hearts. Selected differentially regulated genes such as ß-catenin, SRPK3, ERDR1, ACIN1, Syntaxin-8, and STC1 were validated by real-time PCR. Taken together, this is the first report identifying important, differentially expressed genes during ischemic preconditioning in Nox2(-/-) mice by using microarray analysis.


Assuntos
Precondicionamento Isquêmico Miocárdico/métodos , Glicoproteínas de Membrana/metabolismo , Isquemia Miocárdica/enzimologia , NADPH Oxidases/metabolismo , Animais , Apoptose , Pressão Arterial , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Técnicas In Vitro , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Isquemia Miocárdica/genética , Isquemia Miocárdica/patologia , Reperfusão Miocárdica/métodos , Miócitos Cardíacos/patologia , NADPH Oxidase 2 , NADPH Oxidases/genética , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Fatores de Tempo , Análise Serial de Tecidos , beta Catenina/genética , beta Catenina/metabolismo
7.
Antioxid Redox Signal ; 15(7): 1789-97, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21083501

RESUMO

Hypoxia-inducible transcription factor (HIF)-prolyl hydroxylases domain (PHD-1-3) are oxygen sensors that regulate the stability of the HIFs in an oxygen-dependent manner. Suppression of PHD enzymes leads to stabilization of HIFs and offers a potential treatment option for many ischemic disorders, such as peripheral artery occlusive disease, myocardial infarction, and stroke. Here, we show that homozygous disruption of PHD-1 (PHD-1(-/-)) could facilitate HIF-1α-mediated cardioprotection in ischemia/reperfused (I/R) myocardium. Wild-type (WT) and PHD-1(-/-) mice were randomized into WT time-matched control (TMC), PHD-1(-/-) TMC (PHD1TMC), WT I/R, and PHD-1(-/-) I/R (PHD1IR). Isolated hearts from each group were subjected to 30 min of global ischemia followed by 2 h of reperfusion. TMC hearts were perfused for 2 h 30 min without ischemia. Decreased infarct size (35%±0.6% vs. 49%±0.4%) and apoptotic cardiomyocytes (106±13 vs. 233±21 counts/100 high-power field) were observed in PHD1IR compared to wild-type ischemia/reperfusion (WTIR). Protein expression of HIF-1α was significantly increased in PHD1IR compared to WTIR. mRNA expression of ß-catenin (1.9-fold), endothelial nitric oxide synthase (1.9-fold), p65 (1.9-fold), and Bcl-2 (2.7-fold) were upregulated in the PHD1IR compared with WTIR, which was studied by real-time quantitative polymerase chain reaction. Further, gel-shift analysis showed increased DNA binding activity of HIF-1α and nuclear factor-kappaB in PHD1IR compared to WTIR. In addition, nuclear translocation of ß-catenin was increased in PHD1IR compared with WTIR. These findings indicated that silencing of PHD-1 attenuates myocardial I/R injury probably by enhancing HIF-1α/ß-catenin/endothelial nitric oxide synthase/nuclear factor-kappaB and Bcl-2 signaling pathway.


Assuntos
Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Isquemia Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/patologia , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Animais , Apoptose , Núcleo Celular/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Técnicas de Inativação de Genes , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Técnicas In Vitro , Camundongos , Camundongos Knockout , Isquemia Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/genética , NF-kappa B/genética , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Pró-Colágeno-Prolina Dioxigenase/genética , Ligação Proteica , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Função Ventricular Esquerda , beta Catenina/genética , beta Catenina/metabolismo
8.
J Mol Cell Cardiol ; 50(1): 239-47, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21074540

RESUMO

Oxidative stress plays a crucial role in disruption of neovascularization by alterations in thioredoxin 1 (Trx1) expression and its interaction with other proteins after myocardial infarction (MI). We previously showed that Trx1 has angiogenic properties, but the possible therapeutic significance of overexpressing Trx1 in chronic MI has not been elucidated. Therefore, we explored the angiogenic and cardioprotective potential of Trx1 in an in vivo MI model using transgenic mice overexpressing Trx1. Wild-type (W) and Trx1 transgenic (Trx1(Tg/+)) mice were randomized into W sham (WS), Trx1(Tg/+) sham (TS), WMI, and TMI. MI was induced by permanent occlusion of LAD coronary artery. Hearts from mice overexpressing Trx1 exhibited reduced fibrosis and oxidative stress and attenuated cardiomyocyte apoptosis along with increased vessel formation compared to WMI. We found significant inhibition of Trx1 regulating proteins, TXNIP and AKAP 12, and increased p-Akt, p-eNOS, p-GSK-3ß, HIF-1α, ß-catenin, VEGF, Bcl-2, and survivin expression in TMI compared to WMI. Echocardiography performed 30days after MI revealed significant improvement in myocardial functions in TMI compared to WMI. Our study identifies a potential role for Trx1 overexpression and its association with its regulatory proteins TXNIP, AKAP12, and subsequent activation of Akt/GSK-3ß/ß-catenin/HIF-1α-mediated VEGF and eNOS expression in inducing angiogenesis and reduced ventricular remodeling. Hence, Trx1 and other proteins identified in our study may prove to be potential therapeutic targets in the treatment of ischemic heart disease.


Assuntos
Infarto do Miocárdio/metabolismo , Neovascularização Patológica/metabolismo , Tiorredoxinas/metabolismo , Remodelação Ventricular/fisiologia , Proteínas de Ancoragem à Quinase A/metabolismo , Animais , Western Blotting , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ecocardiografia , Ensaio de Desvio de Mobilidade Eletroforética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Infarto do Miocárdio/genética , Neovascularização Patológica/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/fisiologia , Distribuição Aleatória , Tiorredoxinas/genética , Remodelação Ventricular/genética
9.
PLoS One ; 5(5): e10612, 2010 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-20485525

RESUMO

The current paradigm for elucidating the molecular etiology of cancers relies on the interrogation of small numbers of genes, which limits the scope of investigation. Emerging second-generation massively parallel DNA sequencing technologies have enabled more precise definition of the cancer genome on a global scale. We examined the genome of a human primary malignant pleural mesothelioma (MPM) tumor and matched normal tissue by using a combination of sequencing-by-synthesis and pyrosequencing methodologies to a 9.6X depth of coverage. Read density analysis uncovered significant aneuploidy and numerous rearrangements. Method-dependent informatics rules, which combined the results of different sequencing platforms, were developed to identify and validate candidate mutations of multiple types. Many more tumor-specific rearrangements than point mutations were uncovered at this depth of sequencing, resulting in novel, large-scale, inter- and intra-chromosomal deletions, inversions, and translocations. Nearly all candidate point mutations appeared to be previously unknown SNPs. Thirty tumor-specific fusions/translocations were independently validated with PCR and Sanger sequencing. Of these, 15 represented disrupted gene-encoding regions, including kinases, transcription factors, and growth factors. One large deletion in DPP10 resulted in altered transcription and expression of DPP10 transcripts in a set of 53 additional MPM tumors correlated with survival. Additionally, three point mutations were observed in the coding regions of NKX6-2, a transcription regulator, and NFRKB, a DNA-binding protein involved in modulating NFKB1. Several regions containing genes such as PCBD2 and DHFR, which are involved in growth factor signaling and nucleotide synthesis, respectively, were selectively amplified in the tumor. Second-generation sequencing uncovered all types of mutations in this MPM tumor, with DNA rearrangements representing the dominant type.


Assuntos
Genoma Humano/genética , Mesotelioma/genética , Neoplasias Pleurais/genética , Análise de Sequência de DNA/métodos , Aberrações Cromossômicas , Mapeamento Cromossômico , Cromossomos Humanos Par 21/genética , DNA de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica , Rearranjo Gênico/genética , Genes Neoplásicos/genética , Humanos , Mutação INDEL/genética , Cariotipagem , Mutação Puntual/genética , Polimorfismo de Nucleotídeo Único/genética , Padrões de Referência , Reprodutibilidade dos Testes
10.
Mol Cell Biochem ; 340(1-2): 73-80, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20213262

RESUMO

Calcium is an essential mineral to support bone health and serves as a major therapeutic intervention to prevent and delay the incidence of osteoporosis. Many individuals do not obtain the optimum amount of calcium from diets and depend on bioavailable calcium supplements. The present study was conducted to examine the effect of a novel plant-based calcium supplement, derived from marine algae, and contains high levels of calcium, magnesium, and other bone supporting minerals [commercially known as AlgaeCal (AC)], on proliferation, mineralization, and oxidative stress in cultured human osteoblast cells, and compared with inorganic calcium carbonate and calcium citrate salts. Cultured human fetal osteoblast cells (hFOB 1.19) were treated with AC (0.5 mg/ml, fixed by MTT assay), calcium carbonate, or calcium citrate. These cells were harvested after 4 days of treatment for ALP activity, PCNA expression, and DNA synthesis, and 2 days for Ca(2+) deposition in the presence and absence of vitamin D3 (5 nM). The ability of AC to reduce H(2)O(2) (0.3 mM)-induced oxidative stress was assessed after 24 h of treatment. ALP activity was significantly increased with AC treatment when compared to control, calcium carbonate, or calcium citrate (4.0-, 2.0-, and 2.5-fold, respectively). PCNA expression (immunocytochemical analysis), DNA synthesis (4.0-, 3.0-, and 4.0-fold, respectively), and Ca(2+) deposition (2.0-, 1.0-, and 4.0-fold, respectively) were significantly increased in AC-treated cells when compared with control, calcium carbonate, or calcium citrate treatment. These markers were further enhanced following additional supplementation of vitamin D3 in the AC-treated group cells. AC treatment significantly reduced the H(2)O(2)-induced oxidative stress when compared to calcium carbonate or calcium citrate (1.5- and 1.4-fold, respectively). These findings suggest that AC may serve as a superior calcium supplement as compared to other calcium salts tested in the present study. Hence, AC may be developed as a novel anti-osteoporotic supplement in the near future.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Carbonato de Cálcio/farmacologia , Citrato de Cálcio/farmacologia , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Eucariotos/química , Osteoblastos/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Linhagem Celular , Colecalciferol/farmacologia , Replicação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Peróxido de Hidrogênio/farmacologia , Osteoblastos/metabolismo , Oxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Antígeno Nuclear de Célula em Proliferação/metabolismo , Fatores de Tempo
11.
Circulation ; 121(10): 1244-55, 2010 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-20194885

RESUMO

BACKGROUND: The present study evaluated the reversal of diabetes-mediated impairment of angiogenesis in a myocardial infarction model of type 1 diabetic rats by intramyocardial administration of an adenoviral vector encoding thioredoxin-1 (Ad.Trx1). Various studies have linked diabetes-mediated impairment of angiogenesis to dysfunctional antioxidant systems in which thioredoxin-1 plays a central role. METHODS AND RESULTS: Ad.Trx1 was administered intramyocardially in nondiabetic and diabetic rats immediately after myocardial infarction. Ad.LacZ was similarly administered to the respective control groups. The hearts were excised for molecular and immunohistochemical analysis at predetermined time points. Myocardial function was measured by echocardiography 30 days after the intervention. The Ad.Trx1-administered group exhibited reduced fibrosis, oxidative stress, and cardiomyocyte and endothelial cell apoptosis compared with the diabetic myocardial infarction group, along with increased capillary and arteriolar density. Western blot and immunohistochemical analysis demonstrated myocardial overexpression of thioredoxin-1, heme oxygenase-1, vascular endothelial growth factor, and p38 mitogen-activated protein kinase-beta, as well as decreased phosphorylated JNK and p38 mitogen-activated protein kinase-alpha, in the Ad.Trx1-treated diabetic group. Conversely, we observed a significant reduction in the expression of vascular endothelial growth factor in nondiabetic and diabetic animals treated with tin protoporphyrin (SnPP, a heme oxygenase-1 enzyme inhibitor), even after Ad.Trx1 therapy. Echocardiographic analysis after 4 weeks of myocardial infarction revealed significant improvement in myocardial functional parameters such as ejection fraction, fractional shortening, and E/A ratio in the Ad.Trx1-administered group compared with the diabetic myocardial infarction group. CONCLUSIONS: This study demonstrates for the first time that impairment of angiogenesis and myocardial dysfunction can be regulated by Ad.Trx1 gene therapy in streptozotocin-induced diabetic rats subjected to infarction.


Assuntos
Diabetes Mellitus Experimental/complicações , Terapia Genética , Infarto do Miocárdio/terapia , Neovascularização Fisiológica , Transdução de Sinais , Tiorredoxinas/genética , Remodelação Ventricular , Animais , Apoptose , Células Cultivadas , Células Endoteliais/metabolismo , Fibrose , Heme Oxigenase-1/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/análise , Masculino , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologia , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Estreptozocina , Tiorredoxinas/análise , Transfecção , Fator A de Crescimento do Endotélio Vascular/análise , Proteínas Quinases p38 Ativadas por Mitógeno/análise
12.
J Natl Cancer Inst ; 101(9): 678-86, 2009 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-19401544

RESUMO

BACKGROUND: Malignant pleural mesothelioma has few effective treatments, one being cytoreductive surgery. We previously developed a gene ratio test to predict outcome of malignant pleural mesothelioma patients undergoing surgery. In this study, we investigated the predictive value and technical assay performance of this test in patients with malignant pleural mesothelioma. METHODS: Clinical data were obtained prospectively from 120 consecutive patients with malignant pleural mesothelioma who were scheduled for debulking surgery at one institution. Specimens were obtained at surgery or by pleural biopsy examination. Expression data for four genes were collected from tumor specimens, and three ratios of gene expression (TM4SF1/PKM2, TM4SF1/ARHGDIA, and COBLL1/ARHGDIA) were determined by quantitative reverse transcriptase-polymerase chain reaction. Patients were assigned to good or poor outcome groups by the gene ratio test. Survival was estimated by the Kaplan-Meier method and the log-rank test in univariate analyses. A multivariable Cox proportional hazards model was used to control for prognostic factors. Technical robustness was determined by using up to 30 specimens per patient, two biopsy techniques, and two performance sites. All statistical tests were two-sided. RESULTS: The test predicted overall survival (P < .001) and cancer-specific survival (P = .007) in univariate analysis and overall survival in multivariable analysis (hazard ratio for death = 2.09, 95% confidence interval [CI] = 1.27 to 3.45, P = .004). The test was reproducible within patients and repeatable between two determinations for specimens with widely varying tumor cell contents. Repeatability between two determinations was 88.5% (95% CI = 84.0% to 92.2%) or, when technically unacceptable test values were excluded, 91.9% (95% CI = 87.4% to 95.1%). Reproducibility between two determinations was 96.1% (95% CI = 86.5% to 99.5%). Combining the gene ratio test and other prognostic factors allowed prospective discrimination between patients at high risk (median survival = 6.9 months, 95% CI = 2.6 to 8.9 months; 3-year survival = 0%) and low risk (median survival = 31.9 months, 95% CI = 21.9 to 41.7 months; 3-year survival = 42%). CONCLUSION: The gene ratio test for survival of patients with malignant pleural mesothelioma has robust predictive value and technical assay performance.


Assuntos
Biomarcadores Tumorais/análise , Perfilação da Expressão Gênica , Mesotelioma/química , Mesotelioma/mortalidade , Neoplasias Pleurais/química , Neoplasias Pleurais/mortalidade , Adulto , Idoso , Análise de Variância , Antígenos de Superfície/análise , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Mesotelioma/patologia , Mesotelioma/cirurgia , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Estadiamento de Neoplasias , Razão de Chances , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pleurais/patologia , Neoplasias Pleurais/cirurgia , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Piruvato Quinase/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Biochim Biophys Acta ; 1792(1): 39-48, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19027847

RESUMO

Diabetes, one of the major risk factors of metabolic syndrome culminates in the development of Ischemic Heart Disease (IHD). Refined diets that lack micronutrients, mainly trivalent chromium (Cr(3+)) have been identified as the contributor in the rising incidence of diabetes. We investigated the effect of niacin-bound chromium (NBC) during ischemia/reperfusion (IR) injury in streptozotocin induced diabetic rats. Rats were randomized into: Control (Con); Diabetic (Dia) and Diabetic rats fed with NBC (Dia+NBC). After 30 days of treatment, the isolated hearts were subjected to 30 min of global ischemia followed by 2 h of reperfusion. NBC treatment demonstrated significant increase in left ventricular functions and significant reduction in infarct size and cardiomyocyte apoptosis in Dia+NBC compared with Dia. Increased Glut-4 translocation to the lipid raft fractions was also observed in Dia+NBC compared to Dia. Reduced Cav-1 and increased Cav-3 expression along with phosphorylation of Akt, eNOS and AMPK might have resulted in increased Glut-4 translocation in Dia+NBC. Our results indicate that the cardioprotective effect of NBC is mediated by increased activation of AMPK, Akt and eNOS resulting in increased translocation of Glut-4 to the caveolar raft fractions thereby alleviating the effects of IR injury in the diabetic myocardium.


Assuntos
Cardiotônicos/farmacologia , Cromo/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Transportador de Glucose Tipo 4/metabolismo , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Niacina/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose/efeitos dos fármacos , Transporte Biológico Ativo/efeitos dos fármacos , Cavéolas/efeitos dos fármacos , Cavéolas/metabolismo , Caveolinas/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Técnicas In Vitro , Masculino , Traumatismo por Reperfusão Miocárdica/complicações , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Óxido Nítrico Sintase Tipo III/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley
14.
Free Radic Biol Med ; 45(7): 1027-34, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18694817

RESUMO

Endothelial dysfunction and impaired angiogenesis constitute a hallmark of hypercholesterolemia. This study was designed to examine the effects of resveratrol, an antioxidant with lipid-lowering properties similar to those of statins, on neovascularization along with caveolar interaction with proangiogenic molecules in hypercholesterolemic rats. Animals were divided into: rats maintained on a normal diet (control group); rats maintained on a 5% high-cholesterol diet for 8 weeks (HC group); and rats maintained on a 5% high-cholesterol diet for 8 weeks and administered resveratrol (20 mg/kg) orally for 2 weeks (HCR group). Myocardial infarction was induced by ligating the left anterior descending artery. Herein we examined a novel method for stimulating myocardial angiogenesis by pharmacological preconditioning with resveratrol at both the capillary and arteriolar levels and the potential role of hemeoxygenase-1, endothelial nitric oxide synthase and caveolin-1 in mediating such a response. We also investigated the functional relevance of such treatment by assessing whether the induced neovascularization can help preserve left ventricle-contractile functional reserve in the setting of a chronic hypercholesterolemic condition. Four weeks after sham surgery and left anterior descending artery occlusion, rats underwent echocardiographic evaluation, which revealed improvement in ejection fraction and fractional shortening in the HCR group compared with the HC group. Left ventricular tissue sections displayed increased capillary and arteriolar density in the HCR group compared with the HC group. Western blot analysis revealed downregulation of vascular endothelial growth factor and hemeoxygenase-1 and increased association of caveolin-1 eNOS in the HC group, decreasing the availability of eNOS to the system; which was reversed with resveratrol treatment in the HCR group. This study was further validated in cardiac-specific hemeoxygenase-1-overexpressed mice assuming molecular cross-talk between the targets. Hence, our data identified potential regulators that primarily attenuate endothelial dysfunction by resveratrol therapy in hypercholesterolemic myocardium.


Assuntos
Antioxidantes/farmacologia , Coração/efeitos dos fármacos , Hipercolesterolemia/tratamento farmacológico , Neovascularização Fisiológica/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Western Blotting , Caveolina 1/efeitos dos fármacos , Caveolina 1/metabolismo , Circulação Coronária/efeitos dos fármacos , Heme Oxigenase-1/efeitos dos fármacos , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Hipercolesterolemia/fisiopatologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Transgênicos , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologia , Óxido Nítrico Sintase Tipo III/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Sprague-Dawley , Resveratrol , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo
15.
J Agric Food Chem ; 56(15): 6733-9, 2008 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-18642840

RESUMO

Recent studies on the protection afforded by moderate wine consumption against cardiovascular diseases have focused mainly on the activity of red wine in view of its high content of antioxidants, especially polyphenols. White wine lacks polyphenols, but it contains other compounds such as hydroxycinnamic acids (caffeic acid) and monophenols (tyrosol), which are known to have antioxidant properties. Therefore, this study was designed to examine the effect of white wine in myocardial ischemic-reperfusion injury. The experimental rats were gavaged with white wine (Soave Suavia "Le Rive" 2004) at a dosage of 6.5 mL/(kg.rat.day) for 30 days. Rats were divided into four groups: control sham (CS), wine-treated sham (WS), control ischemia (I)/reperfusion (R) (CIR), and wine + IR (WIR). All the rats in both IR groups underwent 30 min occlusion of the left anterior descending coronary artery followed by 8, 24 h, and 30 days of reperfusion (R). Significant reduction in infarct size (21 vs 39%, n = 6), cardiomyocyte (274 vs 384 counts/100 HPF, n = 6), and endothelial cell apoptosis (387 vs 587 counts/100 HPF) was observed in WIR as compared with CIR after 24 h of reperfusion. Echocardiography demonstrated significant increased fractional shortening (32 vs 22%) and ejection fraction (60 vs 44%) following 30 days of reperfusion in WIR rats compared to CIR ( n = 6). In addition, increased phosphorylation of AKT, Foxo3a, and eNOS were found in WS and WIR, as compared to their respective controls. The gel-shift analysis demonstrated significant upregulation of DNA binding activity of NF-kappaB in the white wine-treated groups. This report demonstrated for the first time that the white wine mediated cardioprotection in ischemic reperfused myocardium is through the PI-3kinase/Akt/FOXO3a/e-NOS/NF-kappaB survival pathway.


Assuntos
Cardiotônicos/administração & dosagem , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Vinho/análise , Animais , Apoptose/efeitos dos fármacos , DNA/metabolismo , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/metabolismo , Masculino , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Infarto do Miocárdio/prevenção & controle , NF-kappa B/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley
16.
Proc Natl Acad Sci U S A ; 105(9): 3521-6, 2008 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-18303113

RESUMO

Cancers arise by the gradual accumulation of mutations in multiple genes. We now use shotgun pyrosequencing to characterize RNA mutations and expression levels unique to malignant pleural mesotheliomas (MPMs) and not present in control tissues. On average, 266 Mb of cDNA were sequenced from each of four MPMs, from a control pulmonary adenocarcinoma (ADCA), and from normal lung tissue. Previously observed differences in MPM RNA expression levels were confirmed. Point mutations were identified by using criteria that require the presence of the mutation in at least four reads and in both cDNA strands and the absence of the mutation from sequence databases, normal adjacent tissues, and other controls. In the four MPMs, 15 nonsynonymous mutations were discovered: 7 were point mutations, 3 were deletions, 4 were exclusively expressed as a consequence of imputed epigenetic silencing, and 1 was putatively expressed as a consequence of RNA editing. Notably, each MPM had a different mutation profile, and no mutated gene was previously implicated in MPM. Of the seven point mutations, three were observed in at least one tumor from 49 other MPM patients. The mutations were in genes that could be causally related to cancer and included XRCC6, PDZK1IP1, ACTR1A, and AVEN.


Assuntos
Regulação Neoplásica da Expressão Gênica , Mesotelioma/genética , Mutação , Proteínas de Neoplasias/genética , Neoplasias Pleurais/genética , Receptores de Ativinas Tipo I/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Antígenos Nucleares/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Autoantígeno Ku , Proteínas de Membrana/genética , Mutação Puntual , Edição de RNA , RNA Neoplásico , Deleção de Sequência
17.
Cancer Chemother Pharmacol ; 61(4): 549-58, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17522864

RESUMO

Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm that is resistant to chemotherapy. Bortezomib is an FDA-approved proteasome inhibitor that is currently under clinical investigation in multiple neoplasms but has not been studied extensively in MPM. In this report, we determine the biological and molecular response of cultured MPM cells to bortezomib alone and in combination with cisplatin or pemetrexed. We used four MPM cell lines (MS589, H28, H2052, JMN), a normal mesothelial cell line (HM3), and a lung cancer cell line (H23) in survival studies utilizing bortezomib, cisplatin, and pemetrexed alone and in combination by administering concurrently or by varying the order of administration. We determined the effect of bortezomib on the cell cycle, apoptosis, and on the expression of cell cycle proteins p21/WAF1 and p27/KIP1 and on apoptosis-related proteins IAP-1, IAP-2, survivin, and XIAP. Bortezomib was highly cytotoxic to MPM cells and induced both G(2)/M and G(1)/S cell cycle arrest. Apoptosis increased in a concentration- and time-dependent manner in 3 of 4 MPM cell lines. Bortezomib stabilized or increased protein levels of p21/WAF1 and IAP-1 and to a lesser degree p27/KIP1, IAP-2, XIAP, and survivin. In combination studies with cisplatin, bortezomib was generally synergistic at high concentrations and antagonistic at low concentrations. Bortezomib increased the cytotoxicity of cisplatin and pemetrexed in a concentration-dependent manner when administered prior to either. Bortezomib may improve outcome in MPM patients alone or in combination with standard chemotherapy but the order of administration is likely to be important. This study justifies further evaluation of bortezomib in MPM.


Assuntos
Antineoplásicos/uso terapêutico , Ácidos Borônicos/uso terapêutico , Mesotelioma/tratamento farmacológico , Neoplasias Pleurais/tratamento farmacológico , Inibidores de Proteassoma , Pirazinas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Bortezomib , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Avaliação Pré-Clínica de Medicamentos , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Citometria de Fluxo , Genes de Partícula A Intracisternal/efeitos dos fármacos , Glutamatos/farmacologia , Guanina/análogos & derivados , Guanina/farmacologia , Humanos , Mesotelioma/patologia , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Pemetrexede , Neoplasias Pleurais/patologia , Análise de Sobrevida
18.
Am J Physiol Heart Circ Physiol ; 292(5): H2060-72, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17277024

RESUMO

Reactive oxygen species (ROS) generated during ischemia-reperfusion (I/R) enhance myocardial injury, but brief periods of myocardial ischemia followed by reperfusion [ischemic preconditioning (IP)] induce cardioprotection. Ischemia is reported to stimulate glucose uptake through the translocation of GLUT-4 from the intracellular vesicles to the sarcolemma. In the present study we demonstrated involvement of ROS in IP-mediated GLUT-4 translocation along with increased expression of caveolin (Cav)-3, phospho (p)-endothelial nitric oxide synthase (eNOS), p-Akt, and decreased expression of Cav-1. The rats were divided into the following groups: 1) control sham, 2) N-acetyl-L-cysteine (NAC, free radical scavenger) sham (NS), 3) I/R, 4) IP + I/R (IP), and 5) NAC + IP (IPN). IP was performed by four cycles of 4 min of ischemia and 4 min of reperfusion followed by 30 min of ischemia and 3, 24, 48 h of reperfusion, depending on the protocol. Increased mRNA expression of GLUT-4 and Cav-3 was observed after 3 h of reperfusion in the IP group compared with other groups. IP increased expression of GLUT-4, Cav-3, and p-AKT and p-eNOS compared with I/R. Coimmunoprecipitation demonstrated decreased association of Cav-1/eNOS in the IP group compared with the I/R group. Significant GLUT-4 and Cav-3 association was also observed in the IP group. This association was disrupted when NAC was used in conjunction with IP. It clearly documents a significant role of ROS signaling in Akt/eNOS/Cav-3-mediated GLUT-4 translocation and association in IP myocardium. In conclusion, we demonstrated a novel redox mechanism in IP-induced eNOS and GLUT-4 translocation and the role of caveolar paradox in making the heart euglycemic during the process of ischemia, leading to myocardial protection in a clinically relevant rat ischemic model.


Assuntos
Caveolinas/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Precondicionamento Isquêmico/métodos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/prevenção & controle , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Masculino , Infarto do Miocárdio/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Transdução de Sinais , Resultado do Tratamento
19.
Proc Natl Acad Sci U S A ; 102(27): 9625-30, 2005 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-15983384

RESUMO

Lung cancer is the leading cause of cancer mortality worldwide, yet there exists a limited view of the genetic lesions driving this disease. In this study, an integrated high-resolution survey of regional amplifications and deletions, coupled with gene-expression profiling of non-small-cell lung cancer subtypes, adenocarcinoma and squamous-cell carcinoma (SCC), identified 93 focal copy-number alterations, of which 21 span <0.5 megabases and contain a median of five genes. Whereas all known lung cancer genes/loci are contained in the dataset, most of these recurrent copy-number alterations are previously uncharacterized and include high-amplitude amplifications and homozygous deletions. Notably, despite their distinct histopathological phenotypes, adenocarcinoma and SCC genomic profiles showed a nearly complete overlap, with only one clear SCC-specific amplicon. Among the few genes residing within this amplicon and showing consistent overexpression in SCC is p63, a known regulator of squamous-cell differentiation. Furthermore, intersection with the published pancreatic cancer comparative genomic hybridization dataset yielded, among others, two focal amplicons on 8p12 and 20q11 common to both cancer types. Integrated DNA-RNA analyses identified WHSC1L1 and TPX2 as two candidates likely targeted for amplification in both pancreatic ductal adenocarcinoma and non-small-cell lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica , Genoma Humano , Neoplasias Pulmonares/genética , Mutação/genética , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Genes Supressores de Tumor , Histona-Lisina N-Metiltransferase , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Fosfoproteínas/genética , Transativadores/genética , Fatores de Transcrição , Proteínas Supressoras de Tumor
20.
J Environ Pathol Toxicol Oncol ; 23(4): 237-51, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15511212

RESUMO

Small cell lung cancer (SCLC) is an aggressive type of lung cancer, for which cytotoxic chemotherapy appears to have reached its maximal efficacy. This neoplasm is characterized by the overexpression of several receptor tyrosine kinases (RTKs), especially c-Kit. The ligand for c-Kit is stem cell factor (SCF). In SCLC, SCF can influence c-Kit activation by autocrine or paracrine mechanisms. We have recently shown that the c-Kit/SCF pathway is operational in SCLC and can be inhibited by Glivec (STI571). Because the inhibition of topoisomerase-I (topo-I) is one approach used to treat SCLC, we determined the effects of c-Kit/SCF signaling on topo-I activity. A unique phosphorylation of c-Kit on amino acid 823 and amino acid 703 was identified with the SCF stimulation of H526 cells. We demonstrate that with SCF stimulation over 16 hours (dose response 0-100 ng/mL) in H526 SCLC cells (c-Kit positive, SCF responsive), a decrease in topo-I activity was observed, whereas in H82 SCLC cells (c-Kit negative, SCF unresponsive) there was no modulation of topo-I activity by SCF. Using STI571 (5 microM, 16 hours) to inhibit the c-Kit pathway following stimulation with SCF (100 ng/mL), an upregulation of topo-I activity was observed in H526 cells but not in H82 cells. Performing viability assays, we show that STI571 in combination with topo-I inhibition by camptothecin or SN38, the active metabolite of irinotecan, can cooperatively inhibit H526 cell viability (but not H82 cell viability) for 72 hours. We also show that STI571 does not directly inhibit topo-I activity in SCLC. The combination of STI571 with topo-I inhibition could provide a useful combination in the treatment of SCLC.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Pequenas/enzimologia , DNA Topoisomerases Tipo I/efeitos dos fármacos , Neoplasias Pulmonares/enzimologia , Piperazinas/farmacologia , Pirimidinas/farmacologia , Inibidores da Topoisomerase I , Benzamidas , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Sobrevivência Celular , Relação Dose-Resposta a Droga , Humanos , Mesilato de Imatinib , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
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