Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Molecules ; 28(20)2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37894640

RESUMEN

Plants are a valuable source of drugs for cancer treatment. Daucus carota has been investigated for its health properties. In particular, Daucus carota L. subsp. Sativus, the common edible carrot root, has been found to be rich in bioactive compounds such as carotenoids and dietary fiber and contains many other functional components with significant health-promoting features, while Daucus carota L. subsp. Carrot (Apiacae), also known as wild carrot, has been usually used for gastric ulcer therapy, diabetes, and muscle pain in Lebanon. Here, we review the chemical composition of Daucus carota L. and the functional properties of both edible and wild carrot subspecies. Then, we focus on compounds with anticancer characteristics identified in both Daucus carota subspecies, and we discuss their potential use in the development of novel anticancer therapeutic strategies.


Asunto(s)
Daucus carota , Daucus carota/química , Líbano
2.
Int J Mol Sci ; 21(3)2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-32013263

RESUMEN

Melanoma is the less common but the most malignant skin cancer. Since the survival rate of melanoma metastasis is about 10-15%, many different studies have been carried out in order to find a more effective treatment. Although the development of target-based therapies and immunotherapeutic strategies has improved chances for patient survival, melanoma treatment still remains a big challenge for oncologists. Here, we collect recent data about the emerging role of melanoma-associated microRNAs (miRNAs) currently available treatments, and their involvement in drug resistance. We also reviewed miRNAs as prognostic factors, because of their chemical stability and resistance to RNase activity, in melanoma progression. Moreover, despite miRNAs being considered small conserved regulators with the limitation of target specificity, we outline the dual role of melanoma-associated miRNAs, as oncogenic and/or tumor suppressive factors, compared to other tumors.


Asunto(s)
Resistencia a Antineoplásicos/genética , Melanoma/terapia , MicroARNs/metabolismo , Neoplasias Cutáneas/terapia , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/metabolismo , Humanos , Inmunoterapia , Melanoma/patología , Factor de Transcripción Asociado a Microftalmía/genética , Factor de Transcripción Asociado a Microftalmía/metabolismo , Factores de Riesgo , Neoplasias Cutáneas/patología
3.
J Transl Med ; 12: 216, 2014 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-25074438

RESUMEN

BACKGROUND: Aurora kinase A (AurkA) is over-expressed in melanoma and its inhibition has been observed to limit tumor growth, suggesting a potential role in melanoma treatment. METHODS: A human melanoma cell line with the B-RAF (V600E) mutation (A375mel) was exposed to B-RAF inhibitor (GSK2118436), MEK inhibitor (GSK1120212) and AurkA inhibitor (MLN8054) as single agents or in various combinations (BRAF plus AurkA inhibitor, MEK plus AurkA inhibitor or triple combination BRAF plus MEK plus AurkA inhibitor). Cell proliferation was assessed using xCELLigence technology. Total protein extracts were examined for p53 and c-Myc protein expression by Western blot analysis. Drug anti-tumor effects were further assessed using a 3D-human melanoma skin reconstruction model, in which tissues were incubated with serum-free medium containing control, B-RAF plus MEK inhibitor, MEK plus AurkA inhibitor or the triple combination. RESULTS: AurkA inhibitor plus B-RAF inhibitor, AurkA inhibitor plus MEK inhibitor or triple combination had a markedly greater anti-proliferative effect on A375 (BRAFV600E) melanoma cells than single agents. In the 3D human skin model, the triple combination had a greater anti-tumor effect at the epidermal/dermal junction than control or either double combination. However, S-100 and Ki-67 positively stained spindle-shaped cells were detected in the dermal stratum, suggesting the presence of alive and proliferating melanoma cells. CONCLUSIONS: These findings provide new prospects for melanoma research, including combined B-RAF/AurkA inhibition for B-RAF mutated melanomas and MEK/AurkA inhibitor combination for patients without B-RAF mutations. Moreover, for the first time, we have shown that a B-RAF, MEK and AurkA inhibitor triple drug combination offers increased efficacy against melanoma cell growth and might be considered as a potential treatment strategy for enhancing clinical response in melanoma. However, although this triple drug combination was more effective at the epidermal/dermal junction, the suggested presence of alive and proliferating melanoma cells in the dermal stratum could result in drug resistance and disease recurrence. Molecular characterization of these dermal cells may be critical for the development of novel therapeutic strategies.


Asunto(s)
Aurora Quinasa A/antagonistas & inhibidores , Melanoma/tratamiento farmacológico , Melanoma/enzimología , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Aurora Quinasa A/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Modelos Biológicos , Proteínas Proto-Oncogénicas B-raf/metabolismo , Piel/efectos de los fármacos
4.
Antioxidants (Basel) ; 12(6)2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37371972

RESUMEN

Breast cancer (BC) remains the leading cause of mortality in women, despite significant advancements in diagnosis. Thus, the identification of new compounds for its treatment is critical. Phytochemicals are known to exhibit anti-cancer properties. Here, we investigated the anti-proliferation potential of extracts from carrot, Calendula officinalis flower, and Aloe vera on breast cancer vs. epithelial cell lines. Various extraction methods were used, and the proliferative effect of the resulting extracts was assessed by proliferation assay on breast cancer and epithelial cell lines. Carrot, Aloe leaf, and Calendula flower extracts were extracted by hexane and methanol methods, and their semi-purified extracts were able to specifically inhibit the proliferation of breast cancer cell lines. The extract composition was investigated by colorimetric assays, UHPLC-HRMS, and MS/MS analysis. All the extracts contained monogalactosyl-monoacylglycerol (MGMG), while digalactosyl-monoacylglycerol (DGMG) and aloe-emodin were found in Aloe, and glycerophosphocholine (GPC) derivatives were identified in Calendula, except for the isomer 2 detected in carrot, suggesting that their observed different anti-proliferative properties may be associated with the different lipid compounds. Interestingly, Calendula extract was able to strongly inhibit the triple negative breast cancer MDA-MB-231 cell line proliferation (about 20% cell survival), supporting MGMG and GPC derivatives as potential drugs for this BC subtype treatment.

5.
Antioxidants (Basel) ; 12(6)2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37372043

RESUMEN

The use of specific inhibitors towards mutant BRAF (BRAFi) and MEK (MEKi) in BRAF-mutated patients has significantly improved progression-free and overall survival of metastatic melanoma patients. Nevertheless, half of the patients still develop resistance within the first year of therapy. Therefore, understanding the mechanisms of BRAFi/MEKi-acquired resistance has become a priority for researchers. Among others, oxidative stress-related mechanisms have emerged as a major force. The aim of this study was to evaluate the contribution of Nrf2, the master regulator of the cytoprotective and antioxidant response, in the BRAFi/MEKi acquired resistance of melanoma. Moreover, we investigated the mechanisms of its activity regulation and the possible cooperation with the oncogene YAP, which is also involved in chemoresistance. Taking advantage of established in vitro melanoma models resistant to BRAFi, MEKi, or dual resistance to BRAFi/MEKi, we demonstrated that Nrf2 was upregulated in melanoma cells resistant to targeted therapy at the post-translational level and that the deubiquitinase DUB3 participated in the control of the Nrf2 protein stability. Furthermore, we found that Nrf2 controlled the expression of YAP. Importantly, the inhibition of Nrf2, directly or through inhibition of DUB3, reverted the resistance to targeted therapies.

6.
Life (Basel) ; 12(8)2022 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-36013424

RESUMEN

The SARS-CoV-2 pandemic, reported for the first time at the end of 2019 in the city of Wuhan (China), has spread worldwide in three years; it lead to the infection of more than 500 million people and about six million dead. SARS-CoV-2 has proved to be very dangerous for human health. Therefore, several efforts have been made in studying this virus. In a short time, about one year, the mechanisms of SARS-CoV-2 infection and duplication and its physiological effect on human have been pointed out. Moreover, different vaccines against it have been developed and commercialized. To date, more than 11 billion doses have been inoculated all over the world. Since the beginning of the pandemic, SARS-CoV-2 has evolved; it has done so by accumulating mutations in the genome, generating new virus versions showing different characteristics, and which have replaced the pre-existing variants. In general, it has been observed that the new variants show an increased infectivity and cause milder symptoms. The latest isolated Omicron variants contain more than 50 mutations in the whole genome and show an infectivity 10-folds higher compared to the wild-type strain. Here, we analyse the SARS-CoV-2 variants from a phylogenetic point of view and hypothesize a future scenario for SARS-CoV-2, by following its evolution to date.

7.
Viruses ; 14(11)2022 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-36366461

RESUMEN

Structural and phylogenetic analysis of the spike glycoprotein highlighted that the last variants, annotated as omicron, have about 30 mutations compared to the initial version reported in China, while the delta variant, supposed to be the omicron ancestor, shows only 7 mutations. Moreover, the five omicron variants were isolated between November 2021 and January 2022, and the last variant BA.2.75, unofficially named centaurus, was isolated in May 2022. It appears that, since the isolation of the delta variant (October 2020) to the omicron BA.1 (November 2021), there was an interval of one year, whereas the five omicron variants were isolated in three months, and after a successive four months period, the BA.2.75 variant was isolated. So, what is the temporal and phylogenetic correlation among all these variants? The analysis of common mutations among delta and the omicron variants revealed: (i) a phylogenetic correlation among these variants; (ii) the existence of BA.1 and BA.2 omicron variants a few months before being isolated; (iii) at least three possible intermediate variants during the evolution of omicron; (iv) the evolution of the BA.2.12.1, BA.4 and BA.5 variants from omicron BA.2; (v) the centaurus variant evolution from omicron BA.2.12.1.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Filogenia , Mutación , Glicoproteína de la Espiga del Coronavirus/genética
8.
Cancers (Basel) ; 13(22)2021 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-34830940

RESUMEN

Malignant melanoma still remains a cancer with very poor survival rates, although it is at the forefront of personalized medicine. Most patients show partial responses and disease progressed due to adaptative resistance mechanisms, preventing long-lasting clinical benefits to the current treatments. The response to therapies can be shaped by not only taking into account cancer cell heterogeneity and plasticity, but also by its structural context as well as the cellular component of the tumor microenvironment (TME). Here, we review the recent development in the field of immunotherapy and target-based therapy and how, in the era of tumor micro-tissue engineering, ex-vivo assays could help to enhance our melanoma biology knowledge in its complexity, translating it in the development of successful therapeutic strategies, as well as in the prediction of therapeutic benefits.

9.
Nutrients ; 12(3)2020 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-32213900

RESUMEN

Cancer is the main cause of mortality and morbidity worldwide. Although a large variety of therapeutic approaches have been developed and translated into clinical protocols, the toxic side effects of cancer treatments negatively impact patients, allowing cancer to grow. Brassica metabolites are emerging as new weapons for anti-cancer therapeutics. The beneficial role of the consumption of brassica vegetables, the most-used vegetables in the Mediterranean diet, particularly broccoli, in the prevention of chronic diseases, including cardiovascular diseases, diabetes, and obesity, has been well-documented. In this review, we discuss the anti-tumor effects of the bioactive compounds from Brassica vegetables with regard to the compounds and types of cancer against which they show activity, providing current knowledge on the anti-cancer effects of Brassica metabolites against major types of tumors. In addition, we discuss the impacts of industrial and domestic processing on the compounds' functional properties before their consumption as well as the main strategies used to increase the content of health-promoting metabolites in Brassica plants through biofortification. Finally, the impacts of microbiota on the compounds' bioactivity are considered. This information will be helpful for the further development of efficacious anti-cancer drugs.


Asunto(s)
Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Brassica/química , Animales , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/uso terapéutico , Disponibilidad Biológica , Brassica/clasificación , Estudios Clínicos como Asunto , Evaluación Preclínica de Medicamentos , Glucosinolatos/química , Glucosinolatos/metabolismo , Glucosinolatos/farmacología , Humanos , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Relación Estructura-Actividad
10.
Theranostics ; 7(7): 2108-2110, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28638488

RESUMEN

Cancer is a very complex disease, where cell alterations (i.e. gene mutations, dysregulated signaling pathway(s) and epigenetic modifications) contribute to its development and progression. Elucidating the connections among these cell modifications is a critical challenge, in order to understand the mechanisms which are activated from cancer cells to survive and proliferate. Interesting, Prof. Peng Hou and colleagues, at the First Affiliated Hospital of Xi'an Jiaotong University in China, identified unknown epigenetic mechanisms and their involvement in the tumorigenesis of B-RAF(V600E)-driven cancer.


Asunto(s)
Melanoma , Carcinogénesis , Línea Celular Tumoral , China , Humanos , Mutación , Proteínas Proto-Oncogénicas B-raf/genética
11.
Oncol Rep ; 38(5): 2741-2751, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29048639

RESUMEN

In the present study, the phenotype of melanoma cells resistant to dabrafenib (a B-RAF inhibitor) was investigated, to shed more light on melanoma resistance to B-RAF inhibition. Melanoma cells resistant to dabrafenib were generated using 3 different cell lines, A375, 397 and 624.38, all carrying B-RAFV600E, and they were characterized by cytofluorometric analysis, Ion Torrent technology, immunofluorescence and biochemistry. All dabrafenib-resistant cells showed, in addition to a re-activation of MAPK signaling, morphological changes compared to their sensitive counterparts, accompanied by an increase in CD90 (mesenchymal marker) expression and a decrease in E-cadherin (epithelial marker) expression, suggesting an epithelial-to-mesenchymal-like phenotypic transition. However, melanoma cells with TGF-ß1-induced epithelial-to-mesenchymal transition (EMT) were more sensitive to dabrafenib treatment compared to the sensitivity noted in the non-TGF­ß1­induced EMT melanoma cells, suggesting that TGF-ß1-induced EMT was not associated with dabrafenib resistance. Although dabrafenib-resistant cells exhibited increased cell motility and E-cadherin/vimentin reorganization, as expected in EMT, all of them showed unvaried E-cadherin mRNA and unchanged Snail protein levels, while Twist1 protein expression was decreased with the exception of A375 dabrafenib-resistant melanoma cells, where it was unaffected. These findings suggest a distinct active EMT-like process adopted by melanoma cells under drug exposure. Furthermore, dabrafenib-resistant cells exhibited stem cell-like features, with Oct4 translocation from the cytoplasm to peri-nuclear sites and nuclei, and increased CD20 expression. In conclusion, our data, in addition to confirming that resistance to dabrafenib is dependent on re-activation of MAPK signaling, suggest that this resistance is linked to a distinct active EMT-like process as well as stem-cell features adopted by melanoma cells.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Resistencia a Antineoplásicos , Transición Epitelial-Mesenquimal , Melanoma/metabolismo , Antígenos CD , Biomarcadores de Tumor/genética , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Humanos , Imidazoles , Sistema de Señalización de MAP Quinasas , Melanoma/genética , Mutación , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Oximas , Fenotipo , Proteínas Proto-Oncogénicas B-raf/genética , Antígenos Thy-1/genética , Antígenos Thy-1/metabolismo , Vimentina/genética , Vimentina/metabolismo
12.
Artículo en Inglés | MEDLINE | ID: mdl-15797521

RESUMEN

The plasma peptide component (PPC) from ten melanoma (Mel), breast cancer (BC) and healthy individuals was examined by a combination of RP-HPLC, surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and tandem mass spectrometry. A three peak pattern (2023, 2039, 2053.5 m/z) was primarily observed in melanoma. Two peaks (2236.1 and of 2356.3 m/z) were found only in BC samples. Fibrinogen alpha and inter-alpha-trypsin inhibitor heavy chain H4 fragments were absent in both tumor samples.


Asunto(s)
Neoplasias de la Mama/sangre , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas/métodos , Melanoma/sangre , Proteínas de Neoplasias/sangre , Péptidos/sangre , Proteómica/métodos , Neoplasias Cutáneas/sangre , Adulto , Anciano , alfa-Globulinas/análisis , Secuencia de Aminoácidos , Femenino , Fibrinógeno/análisis , Perfilación de la Expresión Génica , Humanos , Rayos Láser , Masculino
13.
Cancer Biol Ther ; 16(9): 1375-86, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25835050

RESUMEN

Understanding molecular mechanisms involved in melanoma resistance to drugs is a big challenge. Experimental evidences suggested a correlation between mutational status in B-RAF and melanoma cell susceptibility to drugs, such as paclitaxel, doxorubicin and temozolomide, which generate an accumulation of hydrogen peroxide (H2O2) in the cells. We investigated the survival phenotype and the protein level of c-myc, a B-RAF target molecule, in melanoma cells, carrying a different mutational status in B-RAF, upon paclitaxel, doxorubicin and H2O2 treatment. For the first time, we reported c-myc modulation is critical for melanoma drug response. It appeared drug-specific and post-transcriptionally driven through PP2A; in correlation, cell pre-treatment with okadaic acid (OA), a specific PP2A inhibitor, as well as PP2A silencing of melanoma cells, was able to increase melanoma cell drug-sensitivity and c-myc protein level. This is relevant for designing efficacious therapeutic strategies in melanoma.


Asunto(s)
Antineoplásicos/farmacología , Resistencia a Antineoplásicos , Melanoma/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Neoplasias Cutáneas/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Dacarbazina/análogos & derivados , Dacarbazina/farmacología , Doxorrubicina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Expresión Génica , Humanos , Peróxido de Hidrógeno/farmacología , Melanoma/tratamiento farmacológico , Paclitaxel/farmacología , Proteína Fosfatasa 2/genética , Proteína Fosfatasa 2/metabolismo , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-myc/genética , Neoplasias Cutáneas/tratamiento farmacológico , Temozolomida
14.
Cancer Lett ; 357(1): 286-296, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25444926

RESUMEN

We performed a comparative study between two human metastatic melanoma cell lines (A375 and 526), and melanocytes (FOM78) by gene expression profiling and pathway analysis, using Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) software. Genes involved in Ran signaling were significantly over-represented (p ≤ 0.001) and up-regulated in melanoma cells. A melanoma-associated molecular pathway was identified, where Ran, Aurora Kinase A (AurkA) and TERT were up-regulated, while c-myc and PTEN were down-regulated. A consistent high Ran and AurkA gene expression was detected in about 48% and 53%, respectively, of 113 tissue samples from metastatic melanoma patients. AurkA down-regulation was observed in melanoma cells, by Ran knockdown, suggesting AurkA protein is a Ran downstream target. Furthermore, AurkA inhibition, by exposure of melanoma cells to MLN8054, a specific AurKA inhibitor, induced apoptosis in both melanoma cell lines and molecular alterations in the IPA-identified molecular pathway. These alterations differed between cell lines, with an up-regulation of c-myc protein level observed in 526 cells and a slight reduction seen in A375 cells. Moreover, Ran silencing did not affect the A375 invasive capability, while it was enhanced in 526 cells, suggesting that Ran knockdown, by AurkA down-regulation, resulted in a Ran-independent enhanced melanoma cell invasion. Finally, AurK A inhibition induced a PTEN up-regulation and its action was independent of B-RAF mutational status. These findings provide insights relevant for the development of novel therapeutic strategies as well as for a better understanding of mechanisms underlying therapy resistance in melanoma.


Asunto(s)
Melanoma/genética , Melanoma/metabolismo , Proteína de Unión al GTP ran/metabolismo , Línea Celular Tumoral , Regulación hacia Abajo , Perfilación de la Expresión Génica , Humanos , Melanoma/patología , Transducción de Señal , Transfección , Proteína de Unión al GTP ran/genética
15.
Cell Cycle ; 10(17): 2924-36, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21857157

RESUMEN

We have analyzed the proteomes of two human melanoma cell lines (A375 and 526), and of the human melanocytes, (FOM 78), by two-dimensional electrophoresis (2D-PAGE) and liquid chromatography - tandem mass spectrometry (LC-MS/MS). Our comparative proteomic analysis revealed that six proteins were over-expressed in both melanoma cell lines as compared to melanocytes: galectin-1, inosine-5'-monophosphate dehydrogenase 2, serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform, protein DJ-1, cyclophilin A and cofilin-1. We show, for the first time, that only specific isoforms of these molecules are over-expressed in melanoma. Different protein profiles were also found between each individual melanoma cell line and the melanocytes. s-Methyl-5-thioadenosine phosphorylase, ubiquitin and ribosomal protein S27 a precursor, the basic form of protein DJ-1, annexin a1, proliferation associated protein 2g4, isoform alfa-enolase of alfa-enolase, protein disulfide-isomerase precursor, and elongation factor 2 were more strongly expressed in A375 cells compared to melanocytes. In 526 cells, 60s acidic ribosomal protein p1 and calreticulin precursor were more highly expressed than in melanocytes. These molecular differences may help in better understanding melanoma development and its different responsiveness to therapies. The identified proteins could be exploited as biomarkers or therapeutic targets for melanoma.


Asunto(s)
Melanocitos/metabolismo , Melanoma/metabolismo , Precursores de Proteínas/metabolismo , Proteoma/análisis , Biomarcadores , Western Blotting , Línea Celular Tumoral , Cromatografía Liquida , Cofilina 1/metabolismo , Ciclofilina A/metabolismo , Electroforesis en Gel Bidimensional , Galectina 1/metabolismo , Humanos , IMP Deshidrogenasa/metabolismo , Procesamiento de Imagen Asistido por Computador , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Espectrometría de Masas/métodos , Proteínas Oncogénicas/metabolismo , Proteína Desglicasa DJ-1 , Isoformas de Proteínas/metabolismo , Proteómica
16.
Anal Biochem ; 321(1): 116-24, 2003 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-12963062

RESUMEN

The unambiguous identification of peptides/proteins is crucial for the definition of the proteome. Using ProteinChip Array technology also known as surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS), we developed experimental protocols and probed test conditions required for the protein identification on ProteinChip surfaces. We were able to directly digest peptides/proteins on-chip surfaces by specific proteases, such as trypsin, and to obtain the peptide mass fingerprint of the sample under investigation by its direct analysis on a simple laser desorption/ionization mass spectrometer. Furthermore, tandem mass spectrometry was performed on several of the resulting tryptic peptides by using collision quadrupole time of flight (Qq-TOF) MS/MS via the ProteinChip interface, thus allowing the unambiguous identification of the protein(s) within the sample. In addition, we were able to identify the C-terminal sequence of peptides by their digestion with carboxypeptidase Y directly on ProteinChip surfaces coupled with SELDI-TOF MS analysis of the resulting peptide mass ladders employing the instrument's protein ladder sequence software. Moreover, the removal of up to nine amino acid residues from the C-terminal end of a peptide extends the functional range of Qq-TOF MS/MS sequence determination to over 3000 m/z. The utility of these procedures for the proteome exploration are discussed.


Asunto(s)
Análisis por Matrices de Proteínas/métodos , Proteínas/análisis , Proteínas/química , Análisis de Secuencia de Proteína/métodos , Secuencia de Aminoácidos , Catepsina A/metabolismo , Bases de Datos de Proteínas , Espectrometría de Masas/métodos , Datos de Secuencia Molecular , Proteínas/metabolismo , Proteómica/métodos , Tripsina/metabolismo
17.
J Biol Chem ; 277(50): 48241-7, 2002 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-12374803

RESUMEN

Aes, a 36-kDa acetylesterase from Escherichia coli, belongs to the hormone-sensitive lipase family, and it is involved in the regulation of MalT, the transcriptional activator of the maltose regulon. The activity of MalT is depressed through a direct protein-protein interaction with Aes. Although the effect is clear-cut, the meaning of this interaction and the conditions that trigger it still remain elusive. To perform a comparative thermodynamic study between the mesophilic Aes protein and two homologous thermostable enzymes, Aes was overexpressed in E. coli and purified. At the last step of the purification procedure the enzyme was eluted from a Mono Q HR 5/5 column as a major form migrating, anomalously, at 56 kDa on a calibrated Superdex 75 column. A minor peak that contains the Aes protein and a polypeptide of 50 kDa was also detected. By a combined analysis of size-exclusion chromatography and surface-enhanced laser desorption ionization-time of flight mass spectrometry, it was possible to demonstrate the presence in this peak of a stable 87-kDa complex, containing the Aes protein itself and the 50-kDa polypeptide in a 1:1 ratio. The homodimeric molecular species of Aes and of the 50-kDa polypeptide were also detected. The esterase activity associated with the 87-kDa complex, when assayed with p-nitrophenyl butanoate as substrate, proved 6-fold higher than the activity of the major Aes form of 56 kDa. Amino-terminal sequencing highlighted that the 50-kDa partner of Aes in the complex was the alpha-galactosidase from E. coli. The E. coli cells harboring plasmid pT7-SCII-aes and, therefore, expressing Aes were hampered in their growth on a minimal medium containing raffinose as a sole carbon source. Because alpha-galactosidase is involved in the metabolism of raffinose, the above findings suggest a potential role of Aes in the regulation of carbohydrate metabolism in E. coli.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Escherichia coli/enzimología , Proteínas/metabolismo , alfa-Galactosidasa/metabolismo , Acetilesterasa , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Cartilla de ADN , Escherichia coli/metabolismo , Proteínas de Escherichia coli , Cinética , Datos de Secuencia Molecular , Unión Proteica , Proteínas/química , Proteínas/genética , Proteínas/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
18.
Biochemistry ; 42(20): 6169-78, 2003 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-12755619

RESUMEN

Gross cystic disease fluid protein (GCDFP-15), also known as prolactin-inducible protein (PIP), is a specific breast tumor marker. GCDFP-15/PIP is also identified as gp17 and/or seminal actin-binding protein (SABP) from seminal vesicles and as extraparotid glycoprotein (EP-GP) from salivary glands. It is an aspartyl proteinase able to specifically cleave fibronectin (FN), suggesting a possible involvement in mammary tumor progression and fertilization. Other functions were attributed to this protein(s) on the basis of its ability to interact with an array of molecules such as CD4, actin, and fibrinogen. We investigated the structure of the protein(s) under disease versus physiological conditions by RP-HPLC chromatography, ProteinChip technology, and QStar MS/MS mass spectrometry. The proteins behaved differently when examined by RP-HPLC chromatography and surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF) mass spectrometry, suggesting different conformations and/or tissue-specific posttranslational modifications of the proteins, although their primary structure was identical by MS/MS analysis. Both showed a single N-glycosylation site. A different N-linked glycosylation pattern was observed in pathological GCDFP-15/PIP as compared with physiological gp17/SABP protein by coupling enzymatic digestion and ProteinChip technology. Furthermore, taking advantage of ProteinChip technology, we analyzed the interaction of both proteins with CD4 and FN. We observed that the physiological form was mainly involved in the binding to CD4. Moreover, we defined the specific FN binding-domain of this protein. These data suggested that, depending on its conformational state, the protein could differently bind to its various binding molecules and change its function(s) in the microenviroments where it is expressed.


Asunto(s)
Apolipoproteínas , Proteínas Portadoras/química , Proteínas Portadoras/genética , Glicoproteínas , Proteínas de Transporte de Membrana , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Apolipoproteínas D , Biomarcadores de Tumor/química , Neoplasias de la Mama/química , Antígenos CD4/metabolismo , Proteínas Portadoras/fisiología , Cromatografía Líquida de Alta Presión , Femenino , Glicosilación , Humanos , Masculino , Espectrometría de Masas , Estructura Molecular , Proteínas de Neoplasias/fisiología , Análisis por Matrices de Proteínas , Unión Proteica , Conformación Proteica , Procesamiento Proteico-Postraduccional , Proteómica , Distribución Tisular
19.
Rev. para. med ; 15(1): 69-73, jan.-mar. 2001. ilus
Artículo en Portugués | LILACS | ID: lil-283094

RESUMEN

Linchen aureus é uma variedade de púrpura pigmentar crônica caracterizada por pápulas e placas liquenóides, com tonalidades de cor que variam do amarelo-ouro ao marrom escuro e uma disposição em geral unilateral nos membros inferiores. São apresentados dois casos da doença exibindo aspectos histopatológicos considerados clássicos, porém divergentes na forma de expressão clínica, com destaque para uma rara disposição segmentar-zosteriforme observado em um deles


Asunto(s)
Humanos , Adulto , Masculino , Púrpura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA