Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 135
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Clin Radiol ; 75(7): 561.e1-561.e11, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32183997

RESUMEN

AIM: To investigate the effect of radiomics in the assessment of alterations in canonical cancer pathways in breast cancer. MATERIALS AND METHODS: Eighty-eight biopsy-proven breast cancer cases were included in the present study. Radiomics features were extracted from T1-weighted sagittal dynamic contrast-enhanced magnetic resonance imaging (MRI) images. Radiomics signatures were developed to predict genetic alterations in the cell cycle, Myc, PI3K, RTK/RAS, and p53 signalling pathways by using hypothesis testing combined with least absolute shrinkage and selection operator (LASSO) regression analysis. The predictive powers of the models were examined by the area under the curve (AUC) of the receiver operating characteristic curve. RESULTS: A total of 5,234 radiomics features were obtained from MRI images based on the tumour region of interest. Hypothesis tests screened 250, 229, 156, 785, and 319 radiomics features that were differentially displayed between cell cycle, Myc, PI3K, RTK/RAS, and p53 alterations and no alteration status. According to the LASSO algorithm, 11, 12, 12, 15, and 13 features were identified for the construction of the radiomics signatures to predict cell cycle, Myc, PI3K, RTK/RAS, and p53 alterations, with AUC values of 0.933, 0.926, 0.956, 0.940, and 0.886, respectively. The cell cycle radiomics score correlated closely with the RTK/RAS and p53 radiomics scores. These signatures were also dysregulated in patients with different oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 statuses. CONCLUSION: MRI-based radiogenomics analysis exhibits excellent performance in predicting genetic pathways alterations, thus providing a novel approach for non-invasively obtaining genetic-level molecular characteristics of tumours.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mama/diagnóstico por imagen , Genómica de Imágenes/métodos , Imagen por Resonancia Magnética , Transducción de Señal/genética , Adulto , Anciano , Anciano de 80 o más Años , Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Femenino , Humanos , Persona de Mediana Edad
2.
Zhonghua Wai Ke Za Zhi ; 56(11): 869-872, 2018 Nov 01.
Artículo en Zh | MEDLINE | ID: mdl-30392308

RESUMEN

Von Hippel-Lindau(VHL) syndrome is a rare autosomal dominant hereditary disease, and pancreas is one of the frequently involved intra-abdominal organs, including simple pancreatic cysts, pancreatic serous cystadenomas and neuroendocrine neoplasmas. Most of the VHL-related pancreatic neuroendocrine neoplasmas (VHL-pNEN)were non-functional, but they still have a tendency to be malignant. Treatment options for VHL-pNEN include regular follow-up, surgical resection, and medication therapy. When compared with sporadic pNEN, the malignant degree of VHL-pNEN is lower, with a better prognosis, so the surgical treatment should be carefully considered. The indications of surgery for VHL-pNEN include big primary lesions (≥3 cm), fast tumor doubling time (<500 days), VHL gene mutation on exon 3, malignant manifestations on imaging findings, and functional pNEN lesions. The function-preserving approach should be performed to keep the functional pancreatic parenchyma as much as possible. Even for patients with a late stage malignancy that cannot be radically resected, active medication therapy may still lead to a long-term survival.


Asunto(s)
Cistadenoma Seroso , Tumores Neuroendocrinos , Quiste Pancreático , Neoplasias Pancreáticas , Enfermedad de von Hippel-Lindau , Cistadenoma Seroso/complicaciones , Cistadenoma Seroso/diagnóstico , Humanos , Tumores Neuroendocrinos/complicaciones , Tumores Neuroendocrinos/diagnóstico , Quiste Pancreático/complicaciones , Quiste Pancreático/diagnóstico , Neoplasias Pancreáticas/complicaciones , Neoplasias Pancreáticas/diagnóstico , Enfermedad de von Hippel-Lindau/complicaciones
3.
Exp Cell Res ; 327(1): 12-23, 2014 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-24858563

RESUMEN

Coiled-coil alpha-helical rod protein 1 (CCHCR1) is suggested as a candidate biomarker for psoriasis for more than a decade but its function remains poorly understood because of the inconsistent findings in the literature. CCHCR1 protein is suggested to be localized in the cytoplasm, nucleus, mitochondria, or centrosome and to regulate various cellular functions, including steroidogenesis, proliferation, differentiation, and cytoskeleton organization. In this study, we attempted to find a consensus between these findings by identifying the interaction partners of CCHCR1 using co-immunoprecipiation with a stable cell line expressing EGFP-tagged CCHCR1. Out of more than 100 co-immunoprecipitants identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), the enhancer of mRNA-decapping protein 4 (EDC4), which is a processing body (P-body) component, was particularly found to be the major interacting partner of CCHCR1. Confocal imaging confirmed the localization of CCHCR1 in P-bodies and its N-terminus is required for this subcellular localization, suggesting that CCHCR1 is a novel P-body component. As P-bodies are the site for mRNA metabolism, our findings provide a molecular basis for the function of CCHCR1, any disruption of which may affect the transcriptome of the cell, and causing abnormal cell functions.


Asunto(s)
Estructuras Citoplasmáticas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas/metabolismo , Línea Celular Tumoral , Proteínas Fluorescentes Verdes/metabolismo , Células HeLa , Humanos , Psoriasis/metabolismo
4.
PLoS One ; 18(12): e0294661, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38128007

RESUMEN

The coiled-coil alpha-helical rod protein 1 (CCHCR1) was first identified as a candidate gene in psoriasis and has lately been found to be associated with a wide range of clinical conditions including COVID-19. CCHCR1 is located within P-bodies and centrosomes, but its exact role in these two subcellular structures and its transcriptional control remain largely unknown. Here, we showed that CCHCR1 shares a bidirectional promoter with its neighboring gene, TCF19. This bidirectional promoter is activated by the G1/S-regulatory transcription factor E2F1, and both genes are co-induced during the G1/S transition of the cell cycle. A luciferase reporter assay suggests that the short intergenic sequence, only 287 bp in length, is sufficient for the G1/S induction of both genes, but the expression of CCHCR1 is further enhanced by the presence of exon 1 from both TCF19 and CCHCR1. This research uncovers the transcriptional regulation of the CCHCR1 gene, offering new perspectives on its function. These findings contribute to the broader understanding of diseases associated with CCHCR1 and may serve as a foundational benchmark for future research in these vital medical fields.


Asunto(s)
Factor de Transcripción E2F1 , Psoriasis , Humanos , Factor de Transcripción E2F1/genética , Factor de Transcripción E2F1/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Psoriasis/genética , Psoriasis/metabolismo , Regulación de la Expresión Génica , Ciclo Celular , Factores de Transcripción E2F/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
5.
Stud Health Technol Inform ; 280: 141-145, 2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34190076

RESUMEN

Scoliosis is a 3D deformation of the spinal column, characterized by a lateral deviation of the spine, accompanied by axial rotation of the vertebrae. Adolescent Idiopathic Scoliosis (AIS), is the most common type, affecting children between ages 8 to 18 when bone growth is at its maximum rate. The selection of the most appropriate treatment options is based on the surgeon's experience. So, developing a clinically validated patient-specific model of the spine would aid surgeons in understanding AIS in early stages and propose an efficient method of treatment for the individual patient. This project steps include: Developing a clinically validated patient-specific Reduced Order Finite Element Model (ROFEM) of the spine, predicting AIS progression using data mining and proposing a method of treatment. First we implement FE synergistically with bio-mechanical information, image processing and data science techniques to improve predictive ability. Initial geometry of the spine will be extracted from the x-ray images from different planes and imported to FEM software to generate the spine model and perform analysis. A RO model is developed based on the detailed spinal FEM. Next, a neural network is used to predict the spinal curvature. The ability to predict the severity of AIS will have an immense impact on the treatment of AIS-affected children. Access to a predictive and patient-specific model will enable the physicians to have a better understanding of spinal curvature progression. Consequently, the physicians will be able to educate families, choose the most appropriate treatment option and asses for surgical intervention.


Asunto(s)
Cifosis , Escoliosis , Adolescente , Inteligencia Artificial , Niño , Humanos , Imagenología Tridimensional , Rotación , Escoliosis/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen
6.
J Cell Biochem ; 111(2): 412-24, 2010 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-20503249

RESUMEN

Our previous studies have demonstrated the oxidative stress properties of sodium ascorbate (SAA) and its benzaldehyde derivative (SBA) on cancer cell lines, but the molecular mechanisms mediating their cytotoxicity remain unclear. In this study, we treated human colon cancer HT-29 cells with SAA and SBA, and found a significant exposure time-dependent increase of cytotoxicity in both treatments, with a higher cytotoxicity for 24 h with SAA (IC(50) = 5 mM) than SBA (IC(50) = 10 mM). A short-term treatment of cells with 10 mM SAA for 2 h revealed a destabilization of the lysosomes and subsequent induction of cell death, whereas 10 mM SBA triggered a remarkable production of reactive oxidative species, phosphorylation of survival kinase AKT, expression of cyclin kinase-dependent inhibitor p21, and induction of transient growth arrest. The crucial role of p21 mediating this cytotoxicity was confirmed by isogenic derivatives of the human colon carcinoma HCT116 cell lines (p21(+/+) and p21(-/-)), and immunoprecipitation studies with p21 antibody. The SAA cytotoxicity was blocked by co-incubation with catalase, whereas the SBA cytotoxicity and its subsequent growth arrest were abolished by N-acetyl-L-cysteine (NAC), but was not affected by PI3K phosphorylation inhibitor LY294002, or catalase, suggesting two separated oxidative stress pathways were mediated by these two ascorbates. In addition, neither active caspase 3 nor apoptotic bodies but autophagic vacuoles associated with increased LC3-II were found in SBA-treated HT-29 cells; implicating that SBA induced AKT phosphorylation-autophagy and p21-growth arrest in colon cancer HT-29 cells through an NAC-inhibitable oxidative stress pathway.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Autofagia/efectos de los fármacos , Compuestos de Bencilideno/farmacología , Ciclo Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Estrés Oxidativo/efectos de los fármacos , Antineoplásicos , Antioxidantes , Ácido Ascórbico/farmacología , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Neoplasias del Colon/patología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Tiempo
7.
Euro Surveill ; 14(40)2009 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-19822119

RESUMEN

In May 2008, a report of two workers from the same construction equipment manufacturing plant who were admitted to hospital with Legionnaires disease confirmed by urine antigen prompted an outbreak investigation. Both cases were middle aged men, smokers, and with no travel, leisure or other common community exposure to Legionella sources. There were no wet cooling towers at the plant or in the surrounding area. No increase in respiratory disease or worker absenteeism occurred at the plant during the preceding month. Wider case ascertainment including alerts to hospitals and medical practitioners yielded no further cases. The environmental investigation (and sampling of water systems for Legionella) identified a Legionella pneumophila serogroup1 (Mab 2b) count of >3.0x10(4)cfu/l in water samples from an aqueous metal pre-treatment tunnel, which generates profuse water aerosol. Drainage, cleaning and biocide treatment using thiazalone eliminated Legionella from the system.


Asunto(s)
Enfermedad de los Legionarios/diagnóstico , Enfermedad de los Legionarios/etiología , Metales , Contaminantes del Agua/envenenamiento , Purificación del Agua , Análisis por Conglomerados , Humanos
8.
Br J Pharmacol ; 154(1): 4-12, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18332853

RESUMEN

BACKGROUND AND PURPOSE: Ever since the discovery of photodynamic therapy, there has been a continuous search for more potent photosensitizers. Towards that end, we have synthesized a number of novel phthalocyanine derivatives. The unsymmetrical bisamino silicon(IV) phthalocyanine BAM-SiPc is one of the most potent compounds. In in vitro cell culture, it exhibits high phototoxicity against a number of cancer cell lines. EXPERIMENTAL APPROACH: In the present investigation, the in vivo effect of BAM-SiPc was studied in the tumour-bearing nude mice model. The biodistribution of BAM-SiPc was followed to evaluate its tumour selectivity and rate of clearance. The tumour volume in the hepatocarcinoma HepG2- and the colorectal adenocarcinoma HT29-bearing nude mice was measured after photodynamic therapy. The level of intrinsic toxicity induced was also investigated. Finally, the metabolism of BAM-SiPc in the 'normal' WRL68 liver cells and the hepatocarcinoma HepG2 cells was compared. KEY RESULTS: The results not only showed significant tumour regression of HepG2 and growth inhibition of HT29 in the tumour-bearing nude mice, but also no apparent hepatic or cardiac injury with the protocol used. Histological analyses showed that apoptosis was induced in the solid tumour. BAM-SiPc could be metabolized by WRL68 liver cells but not by the hepatocarcinoma HepG2 cells. Unfortunately, BAM-SiPc did not show any specific targeting towards the tumour tissue. CONCLUSIONS AND IMPLICATIONS: The efficiency of BAM-SiPc in inhibiting tumour growth makes it a good candidate for further evaluation. Enhancement of its uptake in tumour tissue by conjugation with biomolecules is currently under investigation.


Asunto(s)
Indoles/uso terapéutico , Neoplasias Experimentales/terapia , Compuestos de Organosilicio/uso terapéutico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Animales , Línea Celular Tumoral , Células HT29 , Humanos , Etiquetado Corte-Fin in Situ , Técnicas In Vitro , Indoles/farmacocinética , Hígado/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Compuestos de Organosilicio/farmacocinética , Fármacos Fotosensibilizantes/farmacocinética , Distribución Tisular
9.
Anticancer Res ; 28(5A): 2577-84, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19035281

RESUMEN

The cytotoxic activity of sodium 5,6-benzylidene-L-ascorbate (SBA) against eight human cancer cell lines and three human normal cells was investigated, SBA showed slightly higher cytotoxicity against human tumor cell lines, as compared with normal cells, with a tumor-specificity index of 2.0. The human myelogenous leukemia cell lines (HL-60, ML-1, KG-1) were the most sensitive to SBA, followed by human oral squamous cell carcinoma (HSC-2, HSC-3, HSC-4) and human glioblastoma (T98G, U87MG). Human oral normal cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast) were the most resistant. In contrast to actinomycin D, SBA induced little or no activation of caspase-3, caspase-8 and caspase-9 in the HSC-2, HSC-4, T98G and HL-60 cells, regardless of incubation time (either 6 or 24 h). SBA induced little or no internucleosomal DNA fragmentation after 6 h in all of these cells. However, prolonged treatment with SBA (24 h) induced a smear pattern of DNA fragmentation in the HSC-2, HSC-4 and T98G cells and a low level of internucleosomal DNA fragmentation in the HL-60 cells. Electron microscopy demonstrated the destruction of mitochondrial structure and autophagocytosis of broken organelles by SBA in the HSC-2, HSC-4 and HL-60 cells. At higher concentrations of SBA, necrotic cell death was observed in the HSC-2 cells, but not in the T98G cells, where the production of acidic organelles (detected by acridine orange staining) was much lower than that attained by nutritional starvation, a well-defined method of inducing autophagy. The present study suggests that SBA induces various degrees of autophagic cell death, followed by either necrosis or apoptosis at laters stage, depending on the cell type.


Asunto(s)
Antineoplásicos/farmacología , Ácido Ascórbico/análogos & derivados , Compuestos de Bencilideno/farmacología , Ácido Ascórbico/farmacología , Carcinoma de Células Escamosas/tratamiento farmacológico , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Fibroblastos/efectos de los fármacos , Glioblastoma/tratamiento farmacológico , Células HL-60 , Humanos , Leucemia Mieloide/tratamiento farmacológico , Neoplasias de la Boca/tratamiento farmacológico
10.
Biochim Biophys Acta ; 405(2): 522-6, 1975 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-170984

RESUMEN

The free amino groups in ovine lutropin beta subunit were acylated with acetic anhydride and methyl acetimidinate-HCl to produce the corresponding acetyl and acetimidinyl ovine lutropin beta derivative. These two derivatives recombined with ovine lutropin alpha as well as native ovine lutropin beta, but produced lutropin derivatives which were 33-50% less active than the ovine lutropin alpha + ovine lutropin beta in biological assays.


Asunto(s)
Hormona Luteinizante/aislamiento & purificación , Acetilación , Animales , Ácido Ascórbico/metabolismo , Unión Competitiva , Bioensayo , Femenino , Imidas , Hormona Luteinizante/análogos & derivados , Hormona Luteinizante/farmacología , Ovario/efectos de los fármacos , Ovario/metabolismo , Hipófisis/análisis , Ensayo de Unión Radioligante , Receptores de Superficie Celular , Ovinos
11.
Biochim Biophys Acta ; 492(2): 340-56, 1977 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-884134

RESUMEN

By combinations of selective chemical cleavage (cyanogen bromide), selective enzymatic cleavage (trypsin, thermolysin), and random cleavage (partial acid hydrolysis) a series of disulfide-containing peptides have been isolated from ovine lutropin beta subunit. These peptides suggest six disulfide linkages between half-cystine residues in positions 23-72, 26-110, 93-100, 34-88, 9-90, and 38-57. The latter pair was placed by elimination of other possibilities. The first three pairs are in agreement with a report by Chung, D., Sairam, M. R. and Li, C. H. (1975) Int. J. Peptide Protein Res. 7, 487-493; the pair 93-100 has also been detected by Reeve, J. R., Cheng, K. W. and Pierce, J. G. (1975) Biochem. Biophys. Res. Commun. 67, 149-155, using partial reduction and alkylation. In an attempt to improve the efficiency of enzymatic attack, a preliminary partial reduction as per Reeve et al. [16] was done. In this instance a peptide suggesting an additional disulfide linkage between half-cystines 23-26 was obtained as well as peptides consistent with the 23-72 and 26-110 placements. This was interpreted as an artifactual opening and recombining during partial reduction-reoxidation to produce the 23-26 linkage. The placement of three disulfide bonds (34-88, 9-90, and 38-57) is in disagreement with the pairings Chung et al. [15] suggest for these six half-cystine residues. Six reasons for uncertainty in the placement of disulfide bonds are discussed. It is concluded the definitive placement of the disputed three disulfide bonds in ovine lutropin beta subunit remains an open question.


Asunto(s)
Hormona Luteinizante , Secuencia de Aminoácidos , Aminoácidos/análisis , Animales , Sitios de Unión , Disulfuros/análisis , Sustancias Macromoleculares , Fragmentos de Péptidos/análisis , Unión Proteica , Conformación Proteica , Ovinos
12.
Biochim Biophys Acta ; 437(2): 377-83, 1976 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-782529

RESUMEN

The three tryptic glycopeptides from ovine lutropin, in which two were from the alpha-subunit (alpha-56 and alpha-82 glycopeptides) and one from the beta-subunits (beta-13 glycopeptide), have been isolated and their carohydrate compositions analyzed. The results indicate that the alpha-56 glycopeptide has the highest amount of carbohydrate, whereas the beta-13 glycopeptide has the least. In general, each of the glycopeptides has similar distribution of various sugars, i.e. high in mannose and glucosamine and low in fucose, sialic acid, galactose and galactosamine. Within the limit of experimental error, the sum of their carbohydrate composition is in agreement with the published data on the intact hormone or separated subunits.


Asunto(s)
Glicopéptidos , Hormona Liberadora de Gonadotropina , Aminoácidos/análisis , Animales , Fucosa/análisis , Galactosa/análisis , Glucosamina/análisis , Manosa/análisis , Ovinos , Ácidos Siálicos/análisis , Tripsina
13.
Biochim Biophys Acta ; 1671(1-3): 9-17, 2004 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-15026140

RESUMEN

A special group of lectins were isolated from three popular Asian edible mushrooms: Volvariella volvacea, Pleurotus flabellatus and Hericium erinacium, and their mitogenic activities towards mouse T cells were compared to the extensively investigated Agaricus bisporus lectin (ABL) and the Jack bean lectin, Concanavalin A (Con A). Among the four mushroom lectins tested, V. volvacea lectin (VVL) exhibited strong mitogenic activity as demonstrated by 3H-thymidine incorporation, which was at least 10-fold more effective than that of Con A, and the other mushroom lectins did not exhibit any proliferative activity. Treatment with VVL and ABL resulted in activation of the protein tyrosine kinase, p56lck, and expression of early activation markers, CD69 and CD25, but only VVL induced intracellular calcium influx while ABL triggered cell death. The calcium influx was sensitive to calcium channel antagonists such as nifedipine and verapamil. The P. flabellatus lectin (PFL) and H. erinacium lectin (HEL) did not stimulate p56lck expression and cell proliferation. Neither of these lectins interfered with Con A-mediated lymphocyte proliferation, which further indicated that both PFL and HEL were non-mitogenic. Taken all results together, VVL induced mitogenesis through T cell receptors and the subsequent calcium signaling pathway.


Asunto(s)
Agaricales/química , Lectinas/metabolismo , Lectinas/farmacología , Linfocitos T/efectos de los fármacos , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Calcio/metabolismo , Supervivencia Celular , Células Cultivadas , Citometría de Flujo , Lectinas/química , Lectinas Tipo C , Activación de Linfocitos , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Receptores de Interleucina-2/metabolismo , Bazo/citología , Linfocitos T/citología , Linfocitos T/metabolismo
14.
Cancer Lett ; 230(1): 102-10, 2005 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-16253766

RESUMEN

Four isomalabaricane triterpenes were isolated from marine sponge Geodia japonica [W.H. Zhang, C.T. Che, Isomalabaricane-type nortriterpenoids and other constituents of the marine sponge Geodia japonica, J. Nat. Prod. 64 (2001) 1489-1492. ] and their cytotoxicity was evaluated using a human promyelocytic leukemia HL60 cell line. Of the four triterpenes tested, geoditin A was the most cytotoxic to HL60 cells [IC50=3 microg/ml (<6.6 microM)], followed by stellettins A and B, whereas geoditin B exhibited relatively weak cytotoxicity. The treated cells manifested nuclear changes characteristic for apoptosis, and associated with dissipation of mitochondrial membrane potential, activation of caspase 3, and decrease of cytoplasmic proliferating cell nuclear antigen (PCNA), as demonstrated by fluorescence and immunofluorescence microscopy. When the HL60 cells were exposed to geoditin A ranging from 1.25 to 25 microg/ml, a dose-dependent increase of reactive oxygen species, a progressive dissipation of mitochondrial membrane potential, and an increase in annexin V-FITC binding were measured by flow cytometry. Taken together our results suggest that geoditin A markedly induced reactive oxygen species, decreased mitochondrial membrane potential and mediated a caspases 3 apoptosis pathway.


Asunto(s)
Apoptosis/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Especies Reactivas de Oxígeno , Resorcinoles/toxicidad , Triterpenos/toxicidad , Animales , Caspasa 3 , Caspasas/metabolismo , Relación Dosis-Respuesta a Droga , Citometría de Flujo , Geodia/química , Células HL-60 , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/fisiología
15.
Biochem Pharmacol ; 70(2): 287-99, 2005 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-15916751

RESUMEN

A novel beta-carboline alkaloid, tangutorine (benz[f]indolo[2,3-a]quinolizidine) was isolated from the leaves of Nitraria tangutorum L. [Duan JA, Williams ID, Che CT, Zhou RH, Zhao RH, Tangutorine: a novel beta-carboline alkaloid from Nitraria tangutorum. Tetrahedron Lett 1999;40:2593-6], and its unique structural characters led us to initiate a study of its potential anti-proliferation activity. The in vitro treatment with low doses of tangutorine slightly stimulated the proliferation of human colon cancer HT29 cells until at concentrations higher than 6.25 microg/ml when the cell numbers, cellular MTT reduction, and cell proliferation by 3H-thymidine incorporation decreased in a dose-dependent manner (IC50=15 microg/ml=48 microM). Morphological studies of cells by fluorescence and electron microscopy did not show features for apoptosis but only large vacuoles, swollen mitochondria and dense cytoskeletal filaments bunching in the cytoplasm. Immunoblotting analysis revealed a dramatic induction of cyclin kinase inhibitor p21 as well as an inhibition of topoisomerase II expression at 25 microg/ml tangutorine, thereby impeding cell progression from S to G2/M phase. Cells accumulated at G1 phase of the cell cycle at concentrations > or =50 microg/ml tangutorine. Interestingly, some cells escaped from prolonged growth arrest without cell division and resulted in binucleated and polyploid G1 cells. Taken all results together, tangutorine induced a p21 suppression of all cyclins and their associated kinases, such as the topoisomerase II, and thus inhibited normal DNA replication and mitosis.


Asunto(s)
Carbolinas/farmacología , Proteínas de Ciclo Celular/biosíntesis , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Mitosis/efectos de los fármacos , Quinolizinas/farmacología , Carbolinas/química , Carbolinas/aislamiento & purificación , Proteínas de Ciclo Celular/genética , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Relación Dosis-Respuesta a Droga , Regulación Neoplásica de la Expresión Génica/fisiología , Células HT29 , Humanos , Mitosis/fisiología , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Hojas de la Planta , Quinolizinas/química , Quinolizinas/aislamiento & purificación
16.
Int J Biochem Cell Biol ; 32(3): 365-72, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10716633

RESUMEN

The effects of lectins with different carbohydrate-binding specificities on human hepatoma (H3B), human choriocarcinoma (JAr), mouse melanoma (B16) and rat osteosarcoma (ROS) cell lines were investigated. Cell viability was estimated by uptake of crystal violet. Wheat germ lectin was the lectin with the most deleterious effect on the viability of H3B, JAr and ROS cell lines. The cytotoxicity of lectins with similar sugar-binding specificity to wheat germ lectin, including Maackia amurensis lectin and Solanum tuberosum lectin, was weaker than that of wheat germ lectin. N-acetylgalactosamine-and galactose-binding Tricholoma mongolicum lectin ranked third, after wheat germ lectin and Maackia amurensis lectin, with regard to its effect on H3B, and ranked, together with Maackia amurensis lectin, as the lectins with the second most pronounced effects on ROS. However, the cytotoxic effects of Tricholoma mongolicum lectin on JAr were much weaker than those of Maackia amurensis lectin, Solanum tuberosum lectin and Anguilla anguilla lectin. Artocarpus integrifolia lectin, Lens culinaris lectin and Anguilla anguilla lectin possessed milder cytotoxicity than the remaining lectins. which were approximately equipotent. The mannose-binding Narcissus pseudonarcissus and Lens culinaris lectins were only weakly cytotoxic, the exception being a stronger effect on H3B. The N-acetylgalactosamine-binding Glycine max lectin and methylgalactose-binding Artocarpus integrifolia lectin similarly exhibited low cytotoxicity. It can thus be concluded that in general the ranking was wheat germ lectin > Maackia amurensis lectin approximately Trichloma mongolicum lectins > other aforementioned lectins in cytotoxicity. A particular lectin may manifest more conspicuous toxicity on certain cell lines and less on others.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Lectinas/metabolismo , Lectinas/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Coriocarcinoma/tratamiento farmacológico , Coriocarcinoma/metabolismo , Coriocarcinoma/patología , Femenino , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/metabolismo , Melanoma Experimental/patología , Ratones , Neoplasias/patología , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/metabolismo , Osteosarcoma/patología , Embarazo , Ratas , Células Tumorales Cultivadas , Neoplasias Uterinas/tratamiento farmacológico , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patología , Aglutininas del Germen de Trigo/metabolismo , Aglutininas del Germen de Trigo/farmacología
17.
Int J Biochem Cell Biol ; 28(5): 601-7, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8697105

RESUMEN

The aim of this study was to investigate the effects of the mushroom Coriolus versicolor on cells of the immune system. The cultured mycelia of the mushroom Coriolus versicolor and their culture medium were separately extracted with boiling water. The resulting polysaccharopeptide preparations were designated intramycelial (IM) and extramycelial materials (EM), and were separated by gel filtration before determining their effects on lymphocytes and macrophages in vitro and in vivo. After gel filtration on Sepharose 6B, only a single peak with a molecular weight of 13-19 KDa was obtained. Gel filtration of IM and EM on Sephadex G-50 revealed the presence of a larger peak of 28 KDa (from IM) and 15 KDa (from EM) and a smaller peak of 3.5 KDa. IM, EM and their large molecular peaks enhanced the mitogenic response of T-cells from BALB/c mice in vitro. Splenocytes from C57BL/6 mice pre-treated by force-feeding with IM and EM demonstrated an augmented mitogenic response to Con A. The macrophages of C57BL/6 mice that had been pre-treated with IM or EM showed an enhanced production of nitrite ions. The results indicate that both mouse lymphocytes and macrophages were activated by preparations of polysaccharopeptide from cultured mycelia and culture medium of C. versicolor. However, no direct cytotoxic activity against fibroblasts, hepatoma cells and choriocarcinoma cells could be demonstrated.


Asunto(s)
Basidiomycota/química , Macrófagos/efectos de los fármacos , Mitógenos/farmacología , Péptidos/química , Polisacáridos/química , Bazo/efectos de los fármacos , Animales , Línea Celular , Medios de Cultivo , Técnicas de Cultivo , Humanos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Nitritos/metabolismo , Bazo/citología , Estimulación Química , Células Tumorales Cultivadas
18.
Endocrinology ; 124(1): 379-87, 1989 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2462491

RESUMEN

Residues 121-149 of equine LH beta (eLH beta) were removed by a simple mild acid treatment procedure. The modified eLH beta, des(121-149)eLH beta, was isolated by gel permeation chromatography on Sephacryl S-200. Recombination of des(121-149)eLH beta with eLH alpha and ovine LH alpha (oLH alpha) produced LH derivatives as efficiently as recombination with native eLH beta. In rat testicular LH radioligand assay systems employed in this study the potencies of the resulting LH preparations were, in order of decreasing potency: des(121-149)eLH beta:eLH alpha hybrid greater than eLH greater than eLH alpha + beta greater than oLH greater than des(121-149)eLH beta:oLH alpha greater than oLH alpha + eLH beta (1:0.82:0.67:0.15:0.02:0.006, eLH tracer; 1:0.88:0.67:0.21:0.02:0.006, hCG tracer). In a horse testicular LH radioligand assay with eLH tracer, only the equine LH derivatives were active, and the order of potencies was the same: des(121-149)eLH beta:eLH alpha hybrid greater than eLH greater than eLH alpha + beta (1:0.58:0.46). In a rat testicular Leydig cell steroidogenesis assay, eLH was the most active preparation, but the relative potencies of the other preparations remained unchanged: eLH greater than des(121-149)eLH beta:eLH alpha greater than eLH alpha + beta greater than oLH greater than des(121-149)eLH beta:oLH alpha greater than oLH alpha + eLH beta (1:0.61:0.55:0.27:0.004:0.003). We have previously reported that the hybrid consisting of native eLH beta and oLH alpha was inactive (less than 1%) in LH receptor and steroidogenesis assays. The data reported herein confirm this observation and demonstrate that the absence of LH activity in eLH beta:oLH alpha cannot be attributed to the C-terminal extension on eLH beta, since the des(121-149)eLH beta:oLH alpha hybrid LH is also inactive. Examination of the intrinsic FSH activity of eLH in both rat and chicken testicular FSH radioligand assays produced the following results; eLH, recombined eLH subunits, and des(121-149)eLH beta:eLH alpha were all of the same potency (13% and 0.9% as active as eFSH in rats and chickens, respectively). We conclude that the C-terminal extension on eLH and eCG beta-subunits is not involved in subunit association, LH receptor binding, or FSH receptor binding. The derivative des(121-149)eLH beta:eLH alpha provides a model compound that may be useful in determining the role, if any, of the glycoprotein hormone C-terminal extension that appears to have arisen independently at least twice in mammalian evolution.


Asunto(s)
Células Intersticiales del Testículo/metabolismo , Hormona Luteinizante/fisiología , Fragmentos de Péptidos/fisiología , Receptores de HFE/metabolismo , Receptores de HL/metabolismo , Esteroides/biosíntesis , Aminoácidos/análisis , Animales , Bioensayo , Pollos , Electroforesis en Gel de Poliacrilamida , Hormonas Glicoproteicas de Subunidad alfa/fisiología , Caballos , Hidrólisis , Células Intersticiales del Testículo/efectos de los fármacos , Hormona Luteinizante/aislamiento & purificación , Hormona Luteinizante/farmacología , Sustancias Macromoleculares , Masculino , Peso Molecular , Multimerización de Proteína , Ratas , Relación Estructura-Actividad
19.
Endocrinology ; 116(4): 1454-9, 1985 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3918855

RESUMEN

The FSH activity in equine (e) FSH, eLH, eCG, and ovine LH were examined and compared to that in the standard reference preparation NIH FSH-S13 by three types of assay: the FSH radioreceptor assay with rat testicular homogenate and the stimulation of plasminogen activator production and steroidogenic activity in granulosa cells from diethylstilbestrol (DES)- or eCG-primed donor rats. The difference in the two types of granulosa cells was that the eCG-primed cells have already acquired significant aromatase activity. With the exception of oLH, which showed very little FSH activity (approximately 0.03-0.08 X NIH FSH-S13) throughout the three assays, the equine gonadotropins exhibited great variations in activity with respect to each assay. eFSH, the most active molecule in these assays, had an activity of 44 X NIH FSH-S13 in the receptor binding assay, 8.75 X NIH FSH-S13 in plasminogen activator production, and 4-5 X NIH FSH-S13 in steroid production when assayed in the DES-primed granulosa cells. In the eCG-primed cells, eFSH showed an activity of 4.2 X NIH FSH-S13 in plasminogen activator production and 8.2 X NIH FSH-S13 in progesterone production. eLH had an activity of 10 X NIH FSH-S13 in FSH radioreceptor assay, but showed very little activity and behaved like oLH in stimulation of the cellular responses of DES-primed granulosa cells. However, when eLH was assayed in the eCG-primed cells, it did show stimulating activity with respect to the production of plasminogen activator and progesterone; however, the dose-response curves were not parallel to those of eFSH and eCG. eCG had much less FSH receptor-binding activity (0.29 X NIH FSH-S13) than eLH. It behaved like a LH molecule in DES-primed granulosa cells, but did show activity (approximately 1 X NIH FSH-S13) in stimulating the production of plasminogen activator and progesterone in eCG-primed granulosa cells. From these results, we conclude that under our culture conditions, neither eLH nor eCG was active in the DES-primed granulosa cells, but both were active in the eCG-primed cells, and that the choice of assay conditions and reference standards is very important. Different types of assay may give rise to completely different comparisons for the same molecules. The equine gonadotropins provide a particularly dramatic example of such differences.


Asunto(s)
Gonadotropina Coriónica/farmacología , Dietilestilbestrol/farmacología , Hormona Folículo Estimulante/farmacología , Células de la Granulosa/metabolismo , Hormona Luteinizante/farmacología , Animales , Estradiol/biosíntesis , Femenino , Hormona Folículo Estimulante/metabolismo , Caballos , Masculino , Activadores Plasminogénicos/biosíntesis , Progesterona/biosíntesis , Ensayo de Unión Radioligante , Ratas , Valores de Referencia , Factores de Tiempo
20.
Brain Pathol ; 9(4): 721-32, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10517510

RESUMEN

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized clinically by varying degrees of Parkinsonism, cerebellar ataxia and autonomic dysfunction and pathologically by degeneration in the substantia nigra, putamen, olivary nucleus, pontine nuclei and cerebellum. In addition to selective neuronal loss, iron pigment accumulation and gliosis, myelin pathology is increasingly recognized. In affected white matter, myelin displays signs of degeneration and oligodendroglia contain argyrophilic inclusion bodies, so-called glial cytoplasmic inclusions (GCI). GCI are composed of 10-15-nm diameter coated filaments that are immunoreactive for ubiquitin and alpha-synuclein. Similar inclusions are occasionally found in neuronal cell bodies and cell processes in MSA. Given the presence of inclusion bodies composed of synuclein, it is reasonable to assume that biochemical alterations would be detected in synuclein in MSA and indeed this is the case. In MSA synuclein has biophysical properties that suggest increasing insolubility such as sedimentation in dense fractions in sucrose gradients and ready extraction into detergents and formic acid. Surprisingly, these biochemical modifications in synuclein are more widespread in the brain that the obvious pathology and suggest a fundamental molecular characteristic of the disorder. Similar neuronal, and less frequently glial, inclusions are detected in Lewy body disease, where there is also evidence for biophysical alterations in synuclein. Thus, MSA and LBD are both synucleinopathies, and they may comprise different poles of a disease spectrum that includes sporadic disorders as well as genetically determined disorders such as familial Lewy body Parkinsonism.


Asunto(s)
Atrofia de Múltiples Sistemas/patología , Proteínas del Tejido Nervioso/análisis , Humanos , Sinucleínas , alfa-Sinucleína
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA