RESUMO
Lithium is an effective mood stabilizer that has been clinically used to treat bipolar disorder for several decades. Recent studies have suggested that lithium possesses robust neuroprotective and anti-tumor properties. Thus far, a large number of lithium targets have been discovered. Here, we report for the first time that HDAC1 is a target of lithium. Lithium significantly down-regulated HDAC1 at the translational level by targeting HDAC1 mRNA. We also showed that depletion of HDAC1 is essential for the neuroprotective effects of lithium and for the lithium-mediated degradation of mutant huntingtin through the autophagic pathway. Our studies explain the multiple functions of lithium and reveal a novel mechanism for the function of lithium in neurodegeneration.
Assuntos
Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Lítio/farmacologia , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Autofagia , Proteínas CELF1 , Regulação para Baixo/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Células HEK293 , Células HeLa , Histona Desacetilase 1/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Humanos , Proteína Huntingtina , Fármacos Neuroprotetores/farmacologia , Proteólise/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismoRESUMO
AIM: The tumor suppressor in lung cancer-1 (TSLC1) is a candidate tumor suppressor of lung cancer, and frequently inactivated in primary non-small cell lung cancer (NSCLC). In this study, we investigated the effects of TSLC1 mediated by a dual-regulated oncolytic adenovirus on lung cancer, and the mechanisms underlying the antitumor actions. METHODS: The recombinant virus Ad·sp-E1A(Δ24)-TSLC1 was constructed by inserting the TSLC1 gene into the dual-regulated Ad·sp-E1A(Δ24) vector, which contained the survivin promoter and a 24 bp deletion within E1A. The antitumor effects of Ad·sp-E1A(Δ24)-TSLC1 were evaluated in NCI-H460, A549, and H1299 lung cancer cell lines and the normal fibroblast cell line MRC-5, as well as in A549 xenograft model in nude mice. Cell viability was assessed using MTT assay. The expression of TSLC1 and activation of the caspase signaling pathway were detected by Western blot analyses. The tumor tissues from the xenograft models were examined using H&E staining, IHC, TUNEL, and TEM analyses. RESULTS: Infection of A549 lung cancer cells with Ad·sp-E1A(Δ24)-TSLC1 induced high level expression of TSLC1. Furthermore, the Ad·sp-E1A(Δ24)-TSLC1 virus dose-dependently suppressed the viability of NCI-H460, A549, and H1299 lung cancer cells, and did not affect MRC-5 normal fibroblast cells. Infection of NCI-H460, A549, and H1299 lung cancer cells with Ad·sp-E1A(Δ24)-TSLC1 induced apoptosis, and increased activation of caspase-8, caspase-3 and PARP. In A549 xenograft model in nude mice, intratumoral injection of Ad·sp-E1A(Δ24)-TSLC1 significantly suppressed the tumor volume, and increased the survival rate (from less than 15% to 87.5% at d 60). Histological studies showed that injection of Ad·sp-E1A(Δ24)-TSLC1 caused tumor cell apoptosis and virus particle propagation in tumor tissues. CONCLUSION: The oncolytic adenovirus Ad·sp-E1A(Δ24)-TSLC1 exhibits specific antitumor effects, and is a promising agent for the treatment of lung cancer.
Assuntos
Adenoviridae/fisiologia , Moléculas de Adesão Celular/genética , Imunoglobulinas/genética , Neoplasias Pulmonares/terapia , Vírus Oncolíticos/fisiologia , Proteínas Supressoras de Tumor/genética , Animais , Apoptose/fisiologia , Molécula 1 de Adesão Celular , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Fibroblastos/metabolismo , Fibroblastos/virologia , Terapia Genética/métodos , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Células HEK293 , Humanos , Imunoglobulinas/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/virologia , Camundongos , Camundongos Endogâmicos BALB C , Terapia Viral Oncolítica/métodos , Distribuição Aleatória , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
AIM: To investigate the effects of curcumin on the expression of peroxisome proliferator-activated receptordelta (PPARdelta) and related genes in HT-29 cells. METHODS: HT-29 cells were treated with curcumin (0-80 micromol/L) for 24 h. The effects of curcumin on the morphology of HT-29 cells were studied by Hoechst 33342 staining. The activity of caspase-3 was determined using DEVD-pNA as substrate. The levels of peroxisome PPARdelta, 14-3-3epsilon and vascular endothelial growth factor (VEGF) in HT-29 cells were determined by Western blotting analysis and their mRNA expression was determined by real-time quantitative RT-PCR. RESULTS: Treatment with 10-80 micromol/L curcumin induced typical features of apoptosis and activated the caspase-3 in HT-29 cells. The expression of PPARdelta, 14-3-3epsilon and VEGF was reduced and the activity of beta-catenin/Tcf-4 signaling was inhibited by curcumin treatment. CONCLUSION: Curcumin can induce apoptosis of HT-29 cells and down-regulate the expression of PPARdelta, 14-3-3epsilon and VEGF in HT-29.
Assuntos
Neoplasias do Colo/genética , Curcumina/farmacologia , PPAR delta/genética , Proteínas 14-3-3/efeitos dos fármacos , Proteínas 14-3-3/genética , Apoptose/efeitos dos fármacos , Caspase 3/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Regulação para Baixo/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , PPAR delta/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
OBJECTIVE: To investigate the effects of curcumin on release of cytochrome c and expressions of Bcl-2, Bax, Bad, Bcl-xL, caspase-3, poly ADP-ribose polymerase (PARP), and survivin of HT-29 cells. METHODS: HT-29 cells were treated with curcumin (0 approximately 80 micromol/L) for 24 h. The release of cytochrome c from the mitochondria and the apoptosis-related proteins Bax, Bcl-2, Bcl-xL, Bad, caspase-3, PARP, and survivin were determined by Western blot analysis and their mRNA expressions by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Curcumin significantly induced the growth inhibition and apoptosis of HT-29 cells. A decrease in expressions of Bcl-2, Bcl-xL and survivin was observed after exposure to 10 approximately 80 micromol/L curcumin, while the levels of Bax and Bad increased in the curcumin-treated cells. Curcumin also induced the release of cytochrome c, the activation of caspase-3, and the cleavage of PARP in a dose-dependent manner. CONCLUSION: These data suggest that curcumin induced the HT-29 cell apoptosis possibly via the mitochondria-mediated pathway.