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1.
Int J Mol Sci ; 23(12)2022 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-35743016

RESUMEN

An obstacle to effective uniform treatment of glioblastoma, especially at recurrence, is genetic and cellular intertumoral heterogeneity. Hence, personalized strategies are necessary, as are means to stratify potential targeted therapies in a clinically relevant timeframe. Functional profiling of drug candidates against patient-derived glioblastoma organoids (PD-GBO) holds promise as an empirical method to preclinically discover potentially effective treatments of individual tumors. Here, we describe our establishment of a PD-GBO-based functional profiling platform and the results of its application to four patient tumors. We show that our PD-GBO model system preserves key features of individual patient glioblastomas in vivo. As proof of concept, we tested a panel of 41 FDA-approved drugs and were able to identify potential treatment options for three out of four patients; the turnaround from tumor resection to discovery of treatment option was 13, 14, and 15 days, respectively. These results demonstrate that this approach is a complement and, potentially, an alternative to current molecular profiling efforts in the pursuit of effective personalized treatment discovery in a clinically relevant time period. Furthermore, these results warrant the use of PD-GBO platforms for preclinical identification of new drugs against defined morphological glioblastoma features.


Asunto(s)
Glioblastoma , Glioblastoma/patología , Humanos , Modelos Biológicos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Organoides/patología
2.
Cancer Biol Ther ; 23(1): 96-102, 2022 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-35193475

RESUMEN

Lung carcinoids are neuroendocrine tumors representing 1 to 2% of lung cancers. This study outlines the case of a patient with a metastatic lung atypical carcinoid who presented with a pleural effusion and progression of liver metastases after developing resistance to conventional treatments. Personalized functional profiling (PFP), i.e. drug screening, was performed in ex-vivo spheroids obtained from the patient's liver metastasis to identify potential therapeutic options. The drug screening results revealed cediranib, an antiangiogenic drug, as a hit drug for this patient, from a library of 66 Food and Drug Administration (FDA)-approved and investigational drugs. Based on the PFP results and the reported evidence of clinical efficacy of bevacizumab and capecitabine combination in gastro-intestinal neuroendocrine tumors, this combination was given to the patient. Four months later, the pleural effusion and pleura carcinosis regressed and the liver metastasis did not progress. The patient experienced 2 years of a stable disease under the PFP-guided personalized treatment.


Asunto(s)
Tumor Carcinoide , Carcinoma Neuroendocrino , Neoplasias Hepáticas , Neoplasias Pulmonares , Neoplasias Primarias Secundarias , Tumores Neuroendocrinos , Derrame Pleural , Tumor Carcinoide/tratamiento farmacológico , Tumor Carcinoide/patología , Carcinoma Neuroendocrino/patología , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Pulmón/patología , Neoplasias Pulmonares/patología , Neoplasias Primarias Secundarias/patología , Tumores Neuroendocrinos/patología , Derrame Pleural/patología
3.
Cancers (Basel) ; 12(6)2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32575471

RESUMEN

Lung cancer is the deadliest cancer worldwide, mainly due to its advanced stage at the time of diagnosis. A non-invasive method for its early detection remains mandatory to improve patients' survival. Plasma levels of 351 proteins were quantified by Liquid Chromatography-Parallel Reaction Monitoring (LC-PRM)-based mass spectrometry in 128 lung cancer patients and 93 healthy donors. Bootstrap sampling and least absolute shrinkage and selection operator (LASSO) penalization were used to find the best protein combination for outcome prediction. The PanelomiX platform was used to select the optimal biomarker thresholds. The panel was validated in 48 patients and 49 healthy volunteers. A 6-protein panel clearly distinguished lung cancer from healthy individuals. The panel displayed excellent performance: area under the receiver operating characteristic curve (AUC) = 0.999, positive predictive value (PPV) = 0.992, negative predictive value (NPV) = 0.989, specificity = 0.989 and sensitivity = 0.992. The panel detected lung cancer independently of the disease stage. The 6-protein panel and other sub-combinations displayed excellent results in the validation dataset. In conclusion, we identified a blood-based 6-protein panel as a diagnostic tool in lung cancer. Used as a routine test for high- and average-risk individuals, it may complement currently adopted techniques in lung cancer screening.

4.
Br J Cancer ; 119(5): 580-590, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30078843

RESUMEN

BACKGROUND: Distinguishing lung adenocarcinoma (ADC) from squamous cell carcinoma (SCC) has a tremendous therapeutic implication. Sometimes, the commonly used immunohistochemistry (IHC) markers fail to discriminate between them, urging for the identification of new diagnostic biomarkers. METHODS: We performed IHC on tissue microarrays from two cohorts of lung cancer patients to analyse the expression of beta-arrestin-1, beta-arrestin-2 and clinically used diagnostic markers in ADC and SCC samples. Logistic regression models were applied for tumour subtype prediction. Parallel reaction monitoring (PRM)-based mass spectrometry was used to quantify beta-arrestin-1 in plasma from cancer patients and healthy donors. RESULTS: Beta-arrestin-1 expression was significantly higher in ADC versus SCC samples. Beta-arrestin-1 displayed high sensitivity, specificity and negative predictive value. Its usefulness in an IHC panel was also shown. Plasma beta-arrestin-1 levels were considerably higher in lung cancer patients than in healthy donors and were higher in patients who later experienced a progressive disease than in patients showing complete/partial response following EGFR inhibitor therapy. CONCLUSIONS: Our data identify beta-arrestin-1 as a diagnostic marker to differentiate ADC from SCC and indicate its potential as a plasma biomarker for non-invasive diagnosis of lung cancer. Its utility to predict response to EGFR inhibitors is yet to be confirmed.


Asunto(s)
Adenocarcinoma del Pulmón/diagnóstico , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Regulación hacia Arriba , beta-Arrestina 1/metabolismo , Adenocarcinoma del Pulmón/sangre , Adenocarcinoma del Pulmón/metabolismo , Biomarcadores de Tumor/sangre , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/metabolismo , Estudios de Casos y Controles , Diagnóstico Diferencial , Progresión de la Enfermedad , Detección Precoz del Cáncer , Regulación Neoplásica de la Expresión Génica , Humanos , Modelos Logísticos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/metabolismo , Valor Predictivo de las Pruebas , Análisis de Matrices Tisulares , beta-Arrestina 1/sangre
5.
Oncotarget ; 7(43): 71013-71035, 2016 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-27589834

RESUMEN

Personalized medicine has emerged as the future of cancer care to ensure that patients receive individualized treatment specific to their needs. In order to provide such care, molecular techniques that enable oncologists to diagnose, treat, and monitor tumors are necessary. In the field of lung cancer, cell free DNA (cfDNA) shows great potential as a less invasive liquid biopsy technique, and next-generation sequencing (NGS) is a promising tool for analysis of tumor mutations. In this review, we outline the evolution of cfDNA and NGS and discuss the progress of using them in a clinical setting for patients with lung cancer. We also present an analysis of the role of cfDNA as a liquid biopsy technique and NGS as an analytical tool in studying EGFR and MET, two frequently mutated genes in lung cancer. Ultimately, we hope that using cfDNA and NGS for cancer diagnosis and treatment will become standard for patients with lung cancer and across the field of oncology.


Asunto(s)
Ácidos Nucleicos Libres de Células/aislamiento & purificación , ADN de Neoplasias/aislamiento & purificación , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/patología , Medicina de Precisión/métodos , Biomarcadores de Tumor/sangre , Ácidos Nucleicos Libres de Células/genética , Análisis Mutacional de ADN/métodos , Receptores ErbB/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Biopsia Líquida/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Mutación , Proteínas Proto-Oncogénicas c-met/genética
6.
Sci Rep ; 6: 19529, 2016 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-26787294

RESUMEN

MicroRNAs (miRNAs) have emerged as promising cancer biomarkers. However, exploiting their informative potential requires careful optimization of their detection. Here, we compared the efficiency of commonly used RNA extraction kits in miRNA recovery from cells, plasma and urine/plasma-derived exosomes, using single-gene RT-qPCR and miRNA profiling. We used increasing amounts of starting material to investigate the impact of the input material size on miRNA extraction. We showed that miRNA recovery was largely influenced by the isolation method and by the amount of input material. In particular, the miRCURY™ kit provided highly pure RNA. However, its columns poorly recovered miRNAs from limiting amounts of cells and plasma, and rapidly saturated by large RNA species and plasma components, thus impeding miRNA recovery from high input amounts. Overall, the miRNeasy® kit permitted a better miRNA detection despite a less pure extracted RNA. Nevertheless, some miRNAs were preferentially or exclusively isolated by either of the methods. Trizol® LS resulted in very low purity RNA which affected RT-qPCR efficiency. In general, miRCURY™ biofluids kit efficiently extracted miRNAs from plasma. A careful selection of the RNA isolation method and the consideration of the type and size of input material are highly recommended to avoid biased results.


Asunto(s)
MicroARNs/genética , Biomarcadores , Líquidos Corporales/química , Línea Celular Tumoral , Exosomas/química , Perfilación de la Expresión Génica/métodos , Humanos , MicroARNs/sangre , MicroARNs/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad
7.
Proteomics ; 15(18): 3116-25, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26177823

RESUMEN

The quantification of plasma proteins using the high resolution and accurate mass (HR/AM)-based parallel reaction monitoring (PRM) method provides an immediate benefit over the conventional SRM-based method in terms of selectivity. In this study, multiplexed PRM assays were developed to analyze isotypes of serum amyloid A (SAA) proteins in human plasma with a focus on SAA1 and SAA2. Elevated plasma levels of these proteins in patients diagnosed with lung cancer have been reported in previous studies. Since SAA1 and SAA2 are highly homologous, the available immunoassays tend to overestimate their concentrations due to cross-reactivity. On the other hand, when mass spectrometry (MS)-based assays are used, the presence of the several allelic variants may result in a problem of underestimation. In the present study, eight peptides that represent the target proteins at three different levels: isotype-specific (SAA1α,  SAA 1ß,  SAA1γ,  SAA2α,  SAA2ß), protein-specific (SAA1 or SAA2), and pan SAA (SAA1 and SAA2) were chosen to differentiate SAAs in lung cancer plasma samples using a panel of PRM assays. The measurement of specific isotypes, leveraging the analytical performance of PRM, allowed to quantify the allelic variants of both target proteins. The isotypes detected were corroborated with the genetic information obtained from the same samples. The combination of SAA2α and SAA2ß assays representing the total SAA2 concentration demonstrated a superior analytical outcome than the previously used assay on the common peptide when applied to the detection of lung cancer.


Asunto(s)
Biomarcadores de Tumor/sangre , Marcaje Isotópico/métodos , Neoplasias Pulmonares/sangre , Espectrometría de Masas/métodos , Proteína Amiloide A Sérica/análisis , Secuencia de Aminoácidos , Estudios de Casos y Controles , Humanos , Datos de Secuencia Molecular , Alineación de Secuencia
8.
Mol Cancer ; 9: 115, 2010 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-20487546

RESUMEN

BACKGROUND: Chronic lymphocytic leukemia (CLL) cells are often affected by genomic aberrations targeting key regulatory genes. Although fludarabine is the standard first line therapy to treat CLL, only few data are available about the resistance of B cells to this purine nucleoside analog in vivo. Here we sought to increase our understanding of fludarabine action and describe the mechanisms leading to resistance in vivo. We performed an analysis of genomic aberrations, gene expression profiles, and microRNAs expression in CLL blood B lymphocytes isolated during the course of patients' treatment with fludarabine. RESULTS: In sensitive patients, the differentially expressed genes we identified were mainly involved in p53 signaling, DNA damage response, cell cycle and cell death. In resistant patients, uncommon genomic abnormalities were observed and the resistance toward fludarabine could be characterized based on the expression profiles of genes implicated in lymphocyte proliferation, DNA repair, and cell growth and survival. Of particular interest in some patients was the amplification of MYC (8q) observed both at the gene and transcript levels, together with alterations of myc-transcriptional targets, including genes and miRNAs involved in the regulation of cell cycle and proliferation. Differential expression of the sulfatase SULF2 and of miR-29a, -181a, and -221 was also observed between resistant and sensitive patients before treatment. These observations were further confirmed on a validation cohort of CLL patients treated with fludarabine in vitro. CONCLUSION: In the present study we identified genes and miRNAs that may predict clinical resistance of CLL to fludarabine, and describe an interesting oncogenic mechanism in CLL patients resistant to fludarabine by which the complete MYC-specific regulatory network was altered (DNA and RNA levels, and transcriptional targets). These results should prove useful for understanding and overcoming refractoriness to fludarabine and also for predicting the clinical outcome of CLL patients before or early during their treatment.


Asunto(s)
Antineoplásicos/uso terapéutico , Resistencia a Antineoplásicos/genética , Perfilación de la Expresión Génica , Leucemia Linfocítica Crónica de Células B/genética , MicroARNs/genética , Vidarabina/análogos & derivados , Anciano , Hibridación Genómica Comparativa , Femenino , Expresión Génica/efectos de los fármacos , Genes myc/genética , Humanos , Hibridación Fluorescente in Situ , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína p53 Supresora de Tumor/genética , Vidarabina/uso terapéutico
9.
Mol Cancer Ther ; 9(5): 1349-60, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20406947

RESUMEN

Clinical trials have shown activity of the isotype-selective histone deacetylase (HDAC) inhibitor MGCD0103 in different hematologic malignancies. There are data to support the use of HDAC inhibitors in association with other cancer therapies. To propose a rational combination therapy, it is necessary to depict the molecular basis behind the cytotoxic effect of MGCD0103. In this study, we found that MGCD0103 was substantially more toxic in neoplastic B cells relative to normal cells, and we described the death pathways activated by MGCD0103 in B-cell chronic lymphocytic leukemia (CLL) cells from 32 patients. MGCD0103 decreased the expression of Mcl-1 and induced translocation of Bax to the mitochondria, mitochondrial depolarization, and release of cytochrome c in the cytosol. Caspase processing in the presence of the caspase inhibitor Q-VD-OPh and time course experiments showed that caspase-9 was the apical caspase. Thus, MGCD0103 induced the intrinsic pathway of apoptosis in CLL cells. Moreover, MGCD0103 treatment resulted in the activation of a caspase cascade downstream of caspase-9, caspase-dependent amplification of mitochondrial depolarization, activation of calpain, and Bax cleavage. We propose a model whereby the intrinsic pathway of apoptosis triggered by MGCD0103 in CLL is associated with a mitochondrial death amplification loop.


Asunto(s)
Apoptosis/efectos de los fármacos , Benzamidas/farmacología , Caspasas/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Pirimidinas/farmacología , Anciano , Anciano de 80 o más Años , Antineoplásicos/farmacología , Células Cultivadas , Evaluación Preclínica de Medicamentos , Activación Enzimática/efectos de los fármacos , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Leucemia Linfocítica Crónica de Células B/metabolismo , Masculino , Persona de Mediana Edad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/fisiología , Transducción de Señal/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos
10.
Br J Haematol ; 147(5): 662-71, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19793255

RESUMEN

The main challenge in using chemotherapy to treat multiple myeloma (MM) is drug resistance. In order to evaluate the anti-neoplastic properties of a new drug combination in MM, two clinically available drugs, valproic acid (VPA) a histone deacetylase (HDAC) inhibitor and pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, were tested in vitro on MM cell lines and MM patient cells. The sensitivity towards VPA alone was observed on several MM cell lines tested and also on primary myeloma cells and peripheral blood mononuclear cells from healthy donors. Importantly, the addition of a PPARgamma agonist to the VPA treatment increased the cytotoxic effect of VPA in a synergistic/additive manner on the different MM cell lines and MM patient cells. This effect was observed at the physiological range of VPA used to treat epileptic patients. The mechanisms underlying this increase induced a cell cycle arrest and caspase-dependent apoptosis. The potentiation of the effect of VPA by pioglitazone was mediated by higher acetylation levels of histones H3 and H4 compared to levels induced by HDAC inhibitors alone. This association reveals a new promising chemotherapeutic combination to be tested in MM.


Asunto(s)
Antineoplásicos/farmacología , Mieloma Múltiple/patología , PPAR gamma/agonistas , Ácido Valproico/farmacología , Acetilación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Caspasas/fisiología , Ciclo Celular/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales/métodos , Sinergismo Farmacológico , Histonas/metabolismo , Humanos , Pioglitazona , Tiazolidinedionas/farmacología , Células Tumorales Cultivadas
11.
Oncol Rep ; 18(6): 1513-9, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17982638

RESUMEN

1alpha,25-dihydroxyvitamin D3 (VD3) and the EB1089 analog are well known for their roles in the modulation of proliferation and the differentiation of several malignant cells. In addition, VD3 or EB1089 displayed a high disposal of oxidant features and the ability to cause release of reactive oxygen species (ROS). We attempted to enhance HL60 cell differentiation and to limit ROS generation, by the association of deltanoids with doxorubicin and the antioxidants catalase (CAT), superoxide dismutase (SOD) and N-acetyl cystein (NAC). Differentiation of HL60 cells into monocytic lineage was studied by expression of mRNA, protein CD14 and functional differentiation by the nitroblue tetrazolium assay. The 2',7'-dichlorodihydrofluorescein diacetate (H2-DCFDA) dye allowed to evaluate in situ ROS generation. When associated with 0.1 nM EB1089, 15 nM doxorubicin induced an increase of differentiated cell percentage from 29% to 87% and did not affect VD3-treated cells. The association with doxorubicin also induced a significant increase of ROS release (p<0.05) versus VD3 and EB1089-treated cells. These results correspond to additivity of individual effects of doxorubicin and deltanoids. Antioxidant agents (10 nM NAC, 50 U/ml SOD or 2000 U/ml CAT) were associated with 10 nM VD3 or 1 nM EB1089 for 72 h. Compared to VD3 and EB1089 treatments, associations with antioxidants induced a slight increase of differentiated cells and a significant increase of CD14 mRNA. The highest differentiation effect occurred in the case of the EB1089-NAC association. Antioxidants induced a decrease (p<0.05) in ROS release generated by VD3 or EB1089 near the level of untreated cells. Thus, antioxidant agents demonstrated a protective effect against VD3 and EB1089 oxidative cytotoxicity and an enhancement of the monocyte differentiation. Combinations of antioxidants with deltanoids could dissociate the oxidative stress and differentiation.


Asunto(s)
Antioxidantes/farmacología , Diferenciación Celular/efectos de los fármacos , Doxorrubicina/farmacología , Receptores de Lipopolisacáridos/genética , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Acetilcisteína/farmacología , Antineoplásicos/farmacología , Calcitriol/análogos & derivados , Calcitriol/farmacología , Catalasa/farmacología , Células HL-60 , Humanos , Leucemia Promielocítica Aguda , Receptores de Lipopolisacáridos/efectos de los fármacos , ARN Neoplásico/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Superóxido Dismutasa/farmacología
12.
J Photochem Photobiol B ; 87(2): 113-23, 2007 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-17433706

RESUMEN

The binding and the diffusion of mitoxantrone (MTX) through the plasma membrane was performed by Förster resonance energy transfer (FRET) from the membrane fluorescent donor (4Di-10ASP) to the co-localized acceptor MTX. The MTX addition to living 4Di-10ASP-tagged cells resulted in the rapid quenching of the probe emission (1s), revealing the MTX binding to the outer leaflet. Then, a slower quenching (about 90s) occurred which corresponded to the MTX flip-flop into the inner leaflet. Changes of MTX integration into the plasma membrane were described in BCRP-overexpressed cells (HCT-116R) treated with (i) the BCRP inhibitor fumitremorgin C (FTC), (ii) cyclosporin A (CSA) and (iii) benzyl alcohol (BA). Treatments with FTC or CSA showed 80% and 40% higher flip-flop of MTX from the outer to the inner leaflet of HCT-116R cells. The addition of BA clearly increased the MTX integration into both outer and inner leaflets. Confocal fluorescence microscopy displayed that FTC, CSA and BA enhanced MTX accumulation in HCT-116R. In conclusion, Fumitremorgin C and agents modulating MTX accumulation resulted in higher MTX integration in the resistant cell membrane and could disrupt the membrane cohesion. This energy transfer method appears well-adapted to describe the drug diffusion through the plasma membrane of living cells.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Membrana Celular/metabolismo , Transferencia Resonante de Energía de Fluorescencia/métodos , Mitoxantrona/farmacocinética , Proteínas de Neoplasias/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Alcohol Bencilo/farmacología , Línea Celular , Ciclosporina/farmacología , Difusión , Expresión Génica , Humanos , Indoles/farmacología
13.
Int J Oncol ; 30(4): 1003-9, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17332941

RESUMEN

Image cytometric study of pathological specimens or cell lines has suggested that epigenetic mechanisms are likely to play a major role in determining chromatin patterns evaluable through nuclear texture analysis. We previously reported that nuclear textural changes observed in the OV1-VCR etoposide-resistant ovarian carcinoma cell line were associated with an increased acetylated histone H4 level. In this study we analyzed the effects of treatments with the HDAC inhibitor trichostatin A (TSA) or with nickel subsulfide on histone H4 acetylation, nuclear texture, and MDR1 gene expression in drug-sensitive IGROV1 and drug-resistant OV1-VCR cell lines. In IGROV1 cells, TSA induced an increase in acetylated H4 level associated with a chromatin textural decondensation and an increase in MDR1 gene expression. In OV1-VCR cells, a similar increase in H4 acetylation was observed, but nuclear texture or MDR1 gene expression remained unchanged. ChIP analysis revealed that MDR1 gene expression remained stable in TSA-treated OV1-VCR cells despite a localized increase in H4 acetylation at the promoter level. Analysis of the methylation status of MDR1 promoter showed an increase in DNA methylation at 3 specific sites in OV1-VCR cells, that could participate to TSA low responsiveness in these cells. Treatment with nickel subsulfide induced a decrease in H4 acetylation without any effect on nuclear texture characteristics in both cell lines. In OV1-VCR cells, nickel subsulfide induced a significant down-regulation of the MDR1 gene expression. These results indicate that modulation of histone H4 acetylation level can be associated with up- or down-regulation of the MDR1 gene in OV1 cells. However, this modulation does not always result in chromatin pattern alterations and these data emphasize the complexity of chromatin texture regulation in tumor cells.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Carcinoma/genética , Resistencia a Antineoplásicos/genética , Epigénesis Genética , Histonas/metabolismo , Neoplasias Ováricas/genética , Acetilación/efectos de los fármacos , Carcinoma/metabolismo , Línea Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Inhibidores Enzimáticos/farmacología , Femenino , Expresión Génica , Inhibidores de Histona Desacetilasas , Humanos , Neoplasias Ováricas/metabolismo
14.
J Biol Chem ; 281(50): 38721-9, 2006 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-17050546

RESUMEN

Telomestatin is a potent G-quadruplex ligand that interacts with the 3' telomeric overhang, leading to its degradation, and induces a delayed senescence and apoptosis of cancer cells. POT1 and TRF2 were recently identified as specific telomere-binding proteins involved in telomere capping and t-loop maintenance and whose interaction with telomeres is modulated by telomestatin. We show here that the treatment of HT1080 human tumor cells by telomestatin induces a rapid decrease of the telomeric G-overhang and of the double-stranded telomeric repeats. Telomestatin treatment also provokes a strong decrease of POT1 and TRF2 from their telomere sites, suggesting that the ligand triggers the uncapping of the telomere ends. The effect of the ligand is associated with an increase of the gamma-H2AX foci, one part of them colocalizing at telomeres, thus indicating the occurrence of a DNA damage response at the telomere, but also the presence of additional DNA targets for telomestatin. Interestingly, the expression of GFP-POT1 in HT1080 cells increases both telomere and G-overhang length. As compared with HT1080 cells, HT1080GFP-POT1 cells presented a resistance to telomestatin treatment characterized by a protection to the telomestatin-induced growth inhibition and the G-overhang shortening. This protection is related to the initial G-overhang length rather than to its degradation rate and is overcome by increased telomestatin concentration. Altogether these results suggest that telomestatin induced a telomere dysfunction in which G-overhang length and POT1 level are important factors but also suggest the presence of additional DNA sites of action for the ligand.


Asunto(s)
Oxazoles/farmacología , Proteínas de Unión a Telómeros/fisiología , Telómero , Secuencia de Bases , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Daño del ADN , Cartilla de ADN , Técnica del Anticuerpo Fluorescente , Proteínas Fluorescentes Verdes/genética , Humanos , Complejo Shelterina , Proteínas de Unión a Telómeros/genética
15.
Oncol Rep ; 14(6): 1553-8, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16273255

RESUMEN

Although nicotine has been implicated as a potential factor in the pathogenesis of human cancer, its mechanisms of action regarding cancer development remain largely unknown. HL-60 cells were used to investigate the effects of a short-term treatment with nicotine at concentrations found in the blood of smokers. The findings show that nicotine induces chromatin decondensation, histone H3 acetylation and up-regulation of the c-Jun transcription factor mRNA. This increase is inhibited by mecamylamine, a nicotinic receptor antagonist, suggesting that nicotine alters cellular function directly via nicotinic acetylcholine receptors and may then play a role in cell physiology and tumor promotion.


Asunto(s)
Cromatina/efectos de los fármacos , Nicotina/farmacología , Proteínas Proto-Oncogénicas c-jun/genética , Acetilación/efectos de los fármacos , Núcleo Celular/efectos de los fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/metabolismo , Relación Dosis-Respuesta a Droga , Expresión Génica/efectos de los fármacos , Células HL-60 , Histonas/metabolismo , Humanos , Immunoblotting , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patología , Mecamilamina/farmacología , Antagonistas Nicotínicos/farmacología , Proteínas Proto-Oncogénicas c-fos/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
16.
Cancer Biol Ther ; 4(8): 832-9, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16210912

RESUMEN

Nuclear morphological alterations associated with glucocorticoid resistance in human myeloma were evaluated by image cytometry in three human myeloma RPMI 8226 cell sub-lines. Resistance was induced by drug selection using prednisone (8226p), methylprednisolone (8226m) and dexamethasone (8226d), respectively. All these three cell sub lines displayed significant glucocorticoid-resistance without cross-resistance to doxorubicin. Nuclear geometry and texture were analyzed on G0/G1-selected cell nuclei and data compared with cell growth characteristics and membrane expression of CD23, CD38, CD44 and CD58 antigens. When compared to the parental RPMI 8226 cell line, glucocorticoid-resistant cells display a progressive chromatin condensation with heterogeneously distributed large chromatin clumps, a phenomenon not observed in the multidrug-resistant CEM-VLB cells. These alterations were correlated to the resistance index against glucocorticoids and to the expressions of CD38, and of CD44 variant forms CD44v5 and CD44v7-8 antigens. These data suggest that glucocorticoid resistance in RPMI 8226 cells could be associated with sub-visual specific higher-order chromatin organization changes. Furthermore, these alterations are correlated to the expression of membrane markers associated with tumors aggressiveness.


Asunto(s)
Antineoplásicos Hormonales , Núcleo Celular/ultraestructura , Cromatina/ultraestructura , Resistencia a Antineoplásicos , Glucocorticoides , Mieloma Múltiple/ultraestructura , ADP-Ribosil Ciclasa 1/análisis , Antineoplásicos Hormonales/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Cromatina/metabolismo , Dexametasona/farmacología , Doxorrubicina/farmacología , Citometría de Flujo , Glucocorticoides/farmacología , Humanos , Receptores de Hialuranos/análisis , Metilprednisolona/farmacología , Mieloma Múltiple/inmunología , Fenotipo , Prednisona/farmacología
17.
Cytometry A ; 62(2): 109-17, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15517561

RESUMEN

BACKGROUND: Texture analysis of chromatin patterns by image cytometry can be used in the development and refinement of diagnosis and prognosis of cancers and in the follow-up of therapies. However, little is known about the biological mechanisms underlying these patterns. Epigenetic mechanisms as histone posttranslational modifications and particularly histone acetylation could play a major role in the determination of these chromatin patterns and then influence nuclear texture measurements. METHODS: This study examined the consequences of treatment by the histone deacetylase inhibitor trichostatin A (TSA) on the nuclear texture in human cell lines sensitive and resistant to chemotherapy. Small cell lung carcinoma H69 cells and their variant H69-VP, which is resistant to etoposide, were incubated with 100 ng/ml of TSA for 0 to 24 h. Nuclear texture was evaluated by image cytometry and compared with the histone H4 acetylation level measured by western blotting and expression of c-jun gene evaluated by reverse transcription and real-time polymerase chain reaction. RESULTS: TSA treatment induced an increase in histone H4 acetylation level in both cell lines. However, at the level of chromatin texture, sensitive H69 cells displayed a progressive chromatin decondensation up to 24 h, whereas resistant H69-VP showed rapid (8 h) but transient changes. Similarly, expression of c-jun increased regularly in TSA-treated H69 cells. In H69-VP cells, an increase was also observed up to 12 h followed by a decrease after 24 h of treatment. CONCLUSIONS: Analysis of nuclear texture appeared to be a sensitive technique to detect chromatin pattern alterations induced by the histone deacetylase inhibitor TSA in the H69 cell line and enabled the observation of chromatin pattern discrepancies between chemotherapeutic drug-sensitive and drug-resistant cells during this treatment. When c-jun gene expression was analyzed as gene sensitive to epigenetic control, these textural differences seemed to be correlated to gene expression.


Asunto(s)
Núcleo Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Inhibidores Enzimáticos/farmacología , Genes jun/efectos de los fármacos , Ácidos Hidroxámicos/farmacología , Carcinoma de Células Pequeñas/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cromatina/efectos de los fármacos , Epigénesis Genética , Expresión Génica/efectos de los fármacos , Histona Desacetilasas/efectos de los fármacos , Humanos , Citometría de Imagen , Immunoblotting , Neoplasias Pulmonares/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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