Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 6: 28775, 2016 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-27373929

RESUMO

Maple Syrup Urine Disease (MSUD) is an inherited disorder caused by the dysfunction in the branched chain keto-acid dehydrogenase (BCKDH) enzyme. This leads to buildup of branched-chain keto-acids (BCKA) and branched-chain amino acids (BCAA) in body fluids (e.g. keto-isocaproic acid from the BCAA leucine), leading to numerous clinical features including a less understood skeletal muscle dysfunction in patients. KIC is an inhibitor of mitochondrial function at disease relevant concentrations. A murine model of intermediate MSUD (iMSUD) shows significant skeletal muscle dysfunction as by judged decreased muscle fiber diameter. MSUD is an orphan disease with a need for novel drug interventions. Here using a 96-well plate (liquid chromatography- mass spectrometry (LC-MS) based drug-screening platform we show that Metformin, a widely used anti-diabetic drug, reduces levels of KIC in patient-derived fibroblasts by 20-50%. This Metformin-mediated effect was conserved in vivo; Metformin-treatment significantly reduced levels of KIC in the muscle (by 69%) and serum (by 56%) isolated from iMSUD mice, and restored levels of mitochondrial metabolites (e.g. AMP and other TCA). The drug also decreased the expression of mitochondrial branched chain amino transferase (BCAT) which produces KIC in skeletal muscle. This suggests that Metformin can restore skeletal muscle homeostasis in MSUD by decreasing mitochondrial KIC production.


Assuntos
Aminoácidos de Cadeia Ramificada/sangue , Cetose/sangue , Doença da Urina de Xarope de Bordo/sangue , Metformina/farmacologia , Músculo Esquelético/metabolismo , Animais , Cromatografia Líquida , Modelos Animais de Doenças , Feminino , Fibroblastos/metabolismo , Homeostase , Homozigoto , Cetoácidos/metabolismo , Ácidos Cetoglutáricos/metabolismo , Leucina/metabolismo , Masculino , Espectrometria de Massas , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Mutação
2.
Sci Rep ; 6: 29025, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27364765

RESUMO

Various retinal degenerative diseases including dry and neovascular age-related macular degeneration (AMD), retinitis pigmentosa, and diabetic retinopathy are associated with the degeneration of the retinal pigmented epithelial (RPE) layer of the retina. This consequently results in the death of rod and cone photoreceptors that they support, structurally and functionally leading to legal or complete blindness. Therefore, developing therapeutic strategies to preserve cellular homeostasis in the RPE would be a favorable asset in the clinic. The aryl hydrocarbon receptor (AhR) is a conserved, environmental ligand-dependent, per ARNT-sim (PAS) domain containing bHLH transcription factor that mediates adaptive response to stress via its downstream transcriptional targets. Using in silico, in vitro and in vivo assays, we identified 2,2'-aminophenyl indole (2AI) as a potent synthetic ligand of AhR that protects RPE cells in vitro from lipid peroxidation cytotoxicity mediated by 4-hydroxynonenal (4HNE) as well as the retina in vivo from light-damage. Additionally, metabolic characterization of this molecule by LC-MS suggests that 2AI alters the lipid metabolism of RPE cells, enhancing the intracellular levels of palmitoleic acid. Finally, we show that, as a downstream effector of 2AI-mediated AhR activation, palmitoleic acid protects RPE cells from 4HNE-mediated stress, and light mediated retinal degeneration in mice.


Assuntos
Indóis/farmacologia , Substâncias Protetoras/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Retina/efeitos dos fármacos , Aldeídos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Ácidos Graxos Insaturados/metabolismo , Humanos , Indóis/química , Ligantes , Luz , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dibenzodioxinas Policloradas/química , Dibenzodioxinas Policloradas/toxicidade , Substâncias Protetoras/química , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/genética , Retina/metabolismo , Retina/patologia , Retina/efeitos da radiação , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais/efeitos dos fármacos
3.
Mol Carcinog ; 54(7): 554-65, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24347249

RESUMO

Hypoxic conditions in prostate cancer (PCA) are associated with poor prognosis; however, precise mechanism/s through which hypoxia promotes malignant phenotype remains unclear. Here, we analyzed the role of exosomes from hypoxic PCA cells in enhancing the invasiveness and stemness of naïve PCA cells, as well as in promoting cancer-associated fibroblast (CAF) phenotype in prostate stromal cells (PrSC). Human PCA LNCaP and PC3 cells were exposed to hypoxic (1% O2 ) or normoxic (21% O2 ) conditions, and exosomes secreted under hypoxic (Exo(Hypoxic) ) and normoxic (Exo(Normoxic) ) conditions were isolated from conditioned media. Nanoparticle tracking analysis revealed that Exo(Hypoxic) have smaller average size as compared to Exo(Normoxic) . Immunoblotting results showed a higher level of tetraspanins (CD63 and CD81), heat shock proteins (HSP90 and HSP70), and Annexin II in Exo(Hypoxic) compared to Exo(Normoxic) . Co-culturing with Exo(Hypoxic) increased the invasiveness and motility of naïve LNCaP and PC3 cells, respectively. Exo(Hypoxic) also promoted prostasphere formation by both LNCaP and PC3 cells, and enhanced α-SMA (a CAF biomarker) expression in PrSC. Compared to Exo(Normoxic) , Exo(Hypoxic) showed higher metalloproteinases activity and increased level of diverse signaling molecules (TGF-ß2, TNF1α, IL6, TSG101, Akt, ILK1, and ß-catenin). Furthermore, proteome analysis revealed a higher number of proteins in Exo(Hypoxic) (160 proteins) compared to Exo(Normoxic) (62 proteins), primarily associated with the remodeling of epithelial adherens junction pathway. Importantly, Exo(Hypoxic) targeted the expression of adherens junction proteins in naïve PC3 cells. These findings suggest that Exo(Hypoxic) are loaded with unique proteins that could enhance invasiveness, stemness, and induce microenvironment changes; thereby, promoting PCA aggressiveness.


Assuntos
Junções Aderentes/patologia , Exossomos/patologia , Hipóxia/complicações , Próstata/patologia , Neoplasias da Próstata/complicações , Neoplasias da Próstata/patologia , Junções Aderentes/metabolismo , Anexina A2/análise , Anexina A2/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Movimento Celular , Técnicas de Cocultura , Exossomos/metabolismo , Proteínas de Choque Térmico/análise , Proteínas de Choque Térmico/metabolismo , Humanos , Hipóxia/metabolismo , Hipóxia/patologia , Masculino , Metaloproteases/análise , Metaloproteases/metabolismo , Invasividade Neoplásica/patologia , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Proteoma/análise , Proteoma/metabolismo , Transdução de Sinais , Tetraspaninas/análise , Tetraspaninas/metabolismo
4.
Nutr Cancer ; 65 Suppl 1: 3-11, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23682778

RESUMO

The use of systemic chemotherapeutic drugs and molecular-targeted therapies in the treatment of patients with locally advanced or metastatic lung cancer has its limitations due to the associated acute and cumulative dose limiting toxicities and acquisition of drug resistance. Prevention and therapeutic intervention by dietary agents including nutraceuticals which are non-toxic, cost-effective, and physiologically bioavailable, are emerging approaches in lung cancer management. In this regard, silibinin, a natural flavonolignan, has been rigorously evaluated for the prevention and growth control of lung cancer through extensive in vitro and in vivo studies. Successful studies conducted so far, have established that silibinin is effective both alone and in combination with other agents (e.g., chemotherapeutic and epigenetic agents) in significantly inhibiting the growth of lung cancer cells. In vivo, its effects have been shown to be mediated through inhibition of proliferation, angiogenesis and epigenetic-related events. Therefore, the present review focuses on encompassing the efficacy and mechanisms of silibinin against lung cancer.


Assuntos
Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/prevenção & controle , Silimarina/farmacologia , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/prevenção & controle , Linhagem Celular Tumoral , Quimioprevenção , Modelos Animais de Doenças , Epigênese Genética , Humanos , Silibina
5.
J Pharmacol Exp Ther ; 345(2): 206-14, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23461975

RESUMO

Aggressive cancers in the epithelial-to-mesenchymal transition (EMT) phase are characterized by loss of cell adhesion, repression of E-cadherin, and increased cell mobility. Non-small cell lung cancer (NSCLC) differs in basal level of E-cadherin; predominantly exhibiting silenced expression due to epigenetic-related modifications. Accordingly, effective treatments are needed to modulate these epigenetic events that in turn can positively regulate E-cadherin levels. Herein, we investigated silibinin, a natural flavonolignan with anticancer efficacy against lung cancer, either alone or in combination with epigenetic therapies to modulate E-cadherin expression in a panel of NSCLC cell lines. Silibinin combined with HDAC inhibitor Trichostatin A [TSA; 7-[4-(dimethylamino)phenyl]-N-hydroxy-4,6-dimethyl-7-oxohepta-2,4-dienamide] or DNMT inhibitor 5'-Aza-deoxycytidine (Aza) significantly restored E-cadherin levels in NSCLC cells harboring epigenetically silenced E-cadherin expression. These combination treatments also strongly decreased the invasion/migration of these cells, which further emphasized the biologic significance of E-cadherin restoration. Treatment of NSCLC cells, with basal E-cadherin levels, by silibinin further increased the E-cadherin expression and inhibited their migratory and invasive potential. Additional studies showed that silibinin alone as well as in combination with TSA or Aza downmodulate the expression of Zeb1, which is a major transcriptional repressor of E-cadherin. Overall these findings demonstrate the potential of combinatorial treatments of silibinin with HDAC or DNMT inhibitor to modulate EMT events in NSCLC cell lines, leading to a significant inhibition in their migratory and invasive potentials. These results are highly significant, since loss of E-cadherin and metastatic spread of the disease via EMT is associated with poor prognosis and high mortalities in NSCLC.


Assuntos
Antioxidantes/farmacologia , Caderinas/biossíntese , Movimento Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Silimarina/farmacologia , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Decitabina , Sinergismo Farmacológico , Epigênese Genética/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Humanos , Ácidos Hidroxâmicos/farmacologia , Invasividade Neoplásica/patologia , Silibina , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Regulação para Cima/efeitos dos fármacos , Homeobox 1 de Ligação a E-box em Dedo de Zinco
6.
Epigenetics ; 7(10): 1161-72, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22965008

RESUMO

There is a renewed focus on targeted therapy against epigenetic events that are altered during the pathogenesis of lung cancer. However, the use of epigenomic modifiers as monotherapy lacks efficacy; thus, there is a need to develop safe and effective drug combinatorial regimens, which reverse epigenetic modifications and exhibit profound anticancer activity. Based on these perspectives, we evaluated, for the first time, the efficacy and associated mechanisms of a novel combinatorial regimen of histone deacetylase inhibitors (HDACi)-trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA)-with silibinin (a flavonolignan with established pre-clinical anti-lung cancer efficacy) against non-small cell lung cancer (NSCLC). Silibinin inhibited HDAC activity and decreased HDAC1-3 levels in NSCLC cells, leading to an overall increase in global histone acetylation states of histones H3 and H4. Combinations of HDCAi with silibinin synergistically augmented the cytotoxic effects of these single agents, which was associated with a dramatic increase in p21 (Cdkn1a). Subsequent ChIP assay indicated increased acetylated histone H3 and H4 levels on p21 promoter region, resulting in its increased transcription. The enhanced p21 levels promoted proteasomal degradation of cyclin B1, the limited supply of which halts the progression of cells into mitosis. Indeed, the resultant biological effect was a significant G 2/M arrest by the combination treatment, followed by apoptotic cell death. Similar epigenetic modulations were observed in vivo, together with a marked reduction in xenograft growth. These findings are both novel and highly significant in establishing that HDACi with silibinin would be safe and effective to suppress NSCLC growth.


Assuntos
Epigênese Genética/genética , Ácidos Hidroxâmicos/farmacologia , Silimarina/farmacologia , Acetilação , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Ciclina B1/genética , Ciclina B1/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Humanos , Silibina , Vorinostat
7.
Mol Carcinog ; 49(3): 247-58, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19908243

RESUMO

Recent studies show that silibinin possesses a strong antineoplastic potential against many cancers; however, its efficacy and underlying molecular mechanisms in nonsmall cell lung cancer (NSCLC) are not well defined. Herein, we assessed silibinin activity on prime endpoints and key molecular targets such as cell number, cell-cycle progression, and cell-cycle regulatory molecules in three cell lines representing different NSCLC subtypes, namely large cell carcinoma cells (H1299 and H460) and a bronchioalveolar carcinoma cell line (H322). Silibinin treatment (10-75 microM) inhibited cell growth and targeted cell-cycle progressing causing a prominent G(1) arrest in dose- and time-dependent manner. In mechanistic studies, silibinin (50-75 microM) modulated the protein levels of cyclin-dependent kinases (CDKs) (4, 6, and 2), cyclins (D1, D3, and E), CDKIs (p18/INK4C, p21/Cip1, and p27/Kip1) in a differential manner in these three cell lines. Consistent with these observations, silibinin caused a reduction in kinase activity of CDK4 and 2 in all cell lines except no effect on CDK4 kinase activity in H460 cells, and concomitantly reduced Rb phosphorylation. Together, for the first time, these results identify potential molecular targets and anticancer effects of silibinin in NSCLC cells representing different NSCLC subtypes.


Assuntos
Antioxidantes/farmacologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Ciclo Celular/metabolismo , Ciclo Celular/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Silibina , Silimarina/farmacologia , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA