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1.
Brain Res Bull ; 139: 157-166, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29477836

RESUMO

Rapid eye movement sleep (REMS) plays an important role in maintaining brain excitability by regulating noradrenaline (NA) level and Na-K ATPase activity. We showed earlier that REMS deprivation (REMSD) associated elevated NA increased neuronal, while decreased glial Na-K ATPase activity. However, our knowledge was insufficient on how the REMSD-associated effect is sustained particularly under chronic condition. Using Neuro-2a cells as a model, we investigated the molecular mechanism of NA-induced increase in mRNA expression of Na-K ATPase subunit and the enzyme activity. The cells were treated with NA in the presence or absence of either α1- or ß-adrenoceptor (AR) antagonists, Ca++-channel blocker or SERCA-inhibitor, and PKA or PKC inhibitor. We observed that NA acting on α1-AR increased Na-K ATPase activity and mRNA expression of the catalytic α1- and α3-Na-K ATPase subunits in the Neuro-2a cells. Further, PLC and PKC mediated modulation of intracellular Ca++ played a critical role in inducing the mRNA expression. On the other hand NA, acting on ß-AR up-regulated expression of the regulatory ß1-subunit of Na-K ATPase. The involvement of SP1 as well as phospho-CREB transcription factors in the NA-mediated increased expression of various subunit isoforms was established. The results of this study along with that of earlier reports support our proposed working model of NA-induced increase in mRNA expression of specific Na-K ATPase subunit leading to increased Na-K ATPase activity. The findings help us understand the molecular mechanism of NA-induced increased brain excitability, for example, upon REMSD including under chronic condition.


Assuntos
Norepinefrina/farmacologia , Receptores Adrenérgicos alfa/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Adrenérgicos/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Cálcio/metabolismo , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Nucléolo Celular/efeitos dos fármacos , Nucléolo Celular/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Líquido Extracelular/efeitos dos fármacos , Líquido Extracelular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos , Neuroblastoma/patologia , Prazosina/farmacologia , Propranolol/farmacologia , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , RNA Mensageiro/metabolismo , Receptores Adrenérgicos alfa/genética , Detecção de Sinal Psicológico/efeitos dos fármacos
2.
Artif Cells Nanomed Biotechnol ; 46(8): 2082-2087, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29268653

RESUMO

PURPOSE: Tumour seriously affects people's quality of life. Colorectal cancer is a refractory tumour in digestive tract tumors. In colorectal cancer, gene expression abnormalities is the main reason for its incidence, we mainly focus on the molecular mechanism of MTAP in the development of colorectal cancer. METHODS: The tumour tissue and its adjacent tissue samples of 50 patients with colorectal cancer were screened from July 2011 to February 2015, and the expression of MTAP was detected. Cell lines that overexpress MTAP and low expression of MTAP were constructed in colorectal cancer cell lines. The cell proliferation, invasion and migration was detected in the cells with different expression levels of MTAP. Immunohistochemistry was used to detect the expression of MTAP in liver metastasis and to investigate its clinical significance. And statistics of clinical significance. RESULTS: Q-PCR results showed that the expression of MTAP in colorectal cancer cell lines were significantly higher than that normal human colonic myofibroblasts cell line. Cell proliferation test results showed that cell proliferation was accelerated when MTAP was overexpression, cell invasion and migration were simultaneously accelerated. The expression of MTAP in primary liver was positively correlated with metastatic disease in patients with liver metastatic colorectal cancer via EMT. CONCLUSIONS: MTAP accelerates the growth and metastasis of colorectal cancer through EMT.


Assuntos
Linhagem Celular Tumoral/enzimologia , Neoplasias Colorretais/enzimologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Purina-Núcleosídeo Fosforilase/biossíntese , Linhagem Celular Tumoral/patologia , Proliferação de Células , Neoplasias Colorretais/patologia , Humanos , Metástase Neoplásica
3.
PLoS One ; 10(8): e0136250, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26291325

RESUMO

INTRODUCTION: Metformin is proposed as adjuvant therapy in cancer treatment because of its ability to limit cancer incidence by negatively modulating the PI3K/AKT/mTOR pathway. In vitro, in addition to inhibiting cancer cell proliferation, metformin can also induce apoptosis. The molecular mechanism underlying this second effect is still poorly characterized and published data are often contrasting. We investigated how nutrient availability can modulate metformin-induced apoptosis in three breast cancer cell lines. MATERIAL AND METHODS: MCF7, SKBR3 and MDA-MB-231 cells were plated in MEM medium supplemented with increasing glucose concentrations or in DMEM medium and treated with 10 mM metformin. Cell viability was monitored by Trypan Blue assay and treatment effects on Akt/mTOR pathway and on apoptosis were analysed by Western Blot. Moreover, we determined the level of expression of pyruvate kinase M2 (PKM2), a well-known glycolytic enzyme expressed in cancer cells. RESULTS: Our results showed that metformin can induce apoptosis in breast cancer cells when cultured at physiological glucose concentrations and that the pro-apoptotic effect was completely abolished when cells were grown in high glucose/high amino acid medium. Induction of apoptosis was found to be dependent on AMPK activation but, at least partially, independent of TORC1 inactivation. Finally, we showed that, in nutrient-poor conditions, metformin was able to modulate the intracellular glycolytic equilibrium by downregulating PKM2 expression and that this mechanism was mediated by AMPK activation. CONCLUSION: We demonstrated that metformin induces breast cancer cell apoptosis and PKM2 downregulation only in nutrient-poor conditions. Not only glucose levels but also amino acid concentration can influence the observed metformin inhibitory effect on the mTOR pathway as well as its pro-apoptotic effect. These data demonstrate that the reduction of nutrient supply in tumors can increase metformin efficacy and that modulation of PKM2 expression/activity could be a promising strategy to boost metformin anti-cancer effect.


Assuntos
Adjuvantes Farmacêuticos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Piruvato Quinase/antagonistas & inibidores , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Linhagem Celular Tumoral/metabolismo , Meios de Cultura , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Células MCF-7/efeitos dos fármacos , Células MCF-7/enzimologia , Células MCF-7/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
4.
Cancer Res ; 75(18): 3823-31, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26183925

RESUMO

Chordomas are tumors that arise at vertebral bodies and the base of the skull. Although rare in incidence, they are deadly owing to slow growth and a lack of effective therapeutic options. In this study, we addressed the need for chordoma cell systems that can be used to identify therapeutic targets and empower testing of candidate pharmacologic drugs. Eight human chordoma cell lines that we established exhibited cytology, genomics, mRNA, and protein profiles that were characteristic of primary chordomas. Candidate responder profiles were identified through an immunohistochemical analysis of a chordoma tissue bank of 43 patients. Genomic, mRNA, and protein expression analyses confirmed that the new cell systems were highly representative of chordoma tissues. Notably, all cells exhibited a loss of CDKN2A and p16, resulting in universal activation of the CDK4/6 and Rb pathways. Therefore, we investigated the CDK4/6 pathway and responses to the CDK4/6-specific inhibitor palbociclib. In the newly validated system, palbociclib treatment efficiently inhibited tumor cell growth in vitro and a drug responder versus nonresponder molecular signature was defined on the basis of immunohistochemical expression of CDK4/6/pRb (S780). Overall, our work offers a valuable new tool for chordoma studies including the development of novel biomarkers and molecular targeting strategies.


Assuntos
Aminopiridinas/farmacologia , Benzimidazóis/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Cordoma/patologia , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Genes p16 , Terapia de Alvo Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Neoplasias da Coluna Vertebral/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral/enzimologia , Cordoma/enzimologia , Cordoma/genética , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Sacro , Neoplasias da Coluna Vertebral/enzimologia , Neoplasias da Coluna Vertebral/genética , Adulto Jovem
5.
Acta Neuropathol Commun ; 3: 22, 2015 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-25853389

RESUMO

INTRODUCTION: Medulloblastoma (MB) is the most frequent malignant brain tumor in children. Four subgroups with distinct genetic, epigenetic and clinical characteristics have been identified. Survival remains particularly poor in patients with Group 3 tumors harbouring a MYC amplification. We herein explore the molecular mechanisms and translational implications of class I histone deacetylase (HDAC) inhibition in MYC driven MBs. MATERIAL AND METHODS: Expression of HDACs in primary MB subgroups was compared to normal brain tissue. A panel of MB cell lines, including Group 3 MYC amplified cell lines, were used as model systems. Cells were treated with HDAC inhibitors (HDACi) selectively targeting class I or IIa HDACs. Depletion of HDAC2 was performed. Intracellular HDAC activity, cellular viability, metabolic activity, caspase activity, cell cycle progression, RNA and protein expression were analyzed. RESULTS: HDAC2 was found to be overexpressed in MB subgroups with poor prognosis (SHH, Group 3 and Group 4) compared to normal brain and the WNT subgroup. Inhibition of the enzymatic activity of the class I HDACs reduced metabolic activity, cell number, and viability in contrast to inhibition of class IIa HDACs. Increased sensitivity to HDACi was specifically observed in MYC amplified cells. Depletion of HDAC2 increased H4 acetylation and induced cell death. Simulation of clinical pharmacokinetics showed time-dependent on target activity that correlated with binding kinetics of HDACi compounds. CONCLUSIONS: We conclude that HDAC2 is a valid drug target in patients with MYC amplified MB. HDACi should cover HDAC2 in their inhibitory profile and timing and dosing regimen in clinical trials should take binding kinetics of compounds into consideration.


Assuntos
Amplificação de Genes/efeitos dos fármacos , Genes myc/efeitos dos fármacos , Histona Desacetilase 2/metabolismo , Meduloblastoma/classificação , Meduloblastoma/enzimologia , Caspases/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Linhagem Celular Tumoral/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Criança , Inibidores de Histona Desacetilases/farmacologia , Humanos , Meduloblastoma/metabolismo
6.
Oncotarget ; 6(1): 345-54, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25514600

RESUMO

The small molecule anticancer agent NSC-743380 modulates functions of multiple cancer-related pathways and is highly active in a subset of cancer cell lines in the NCI-60 cell line panel. It also has promising in vivo anticancer activity. However, the mechanisms underlying NSC-743380's selective anticancer activity remain uncharacterized. To determine biomarkers that may be used to identify responders to this novel anticancer agent, we performed correlation analysis on NSC-743380's anticancer activity and the gene expression levels in NCI-60 cell lines and characterized the functions of the top associated genes in NSC-743380-mediated anticancer activity. We found sulfotransferase SULT1A1 is causally associated with NSC-743380's anticancer activity. SULT1A1 was expressed in NSC-743380-sensitive cell lines but was undetectable in resistant cancer cells. Ectopic expression of SULT1A1 in NSC743380 resistant cancer cells dramatically sensitized the resistant cells to NSC-743380. Knockdown of the SULT1A1 in the NSC-743380 sensitive cancer cell line rendered it resistance to NSC-743380. The SULT1A1 protein levels in cell lysates from 18 leukemia cell lines reliably predicted the susceptibility of the cell lines to NSC-743380. Thus, expression of SULT1A1 in cancer cells is required for NSC-743380's anticancer activity and can be used as a biomarker for identification of NSC-743380 responders.


Assuntos
Antineoplásicos/farmacologia , Arilsulfotransferase/biossíntese , Linhagem Celular Tumoral/efeitos dos fármacos , Indóis/farmacologia , Biomarcadores Tumorais/análise , Western Blotting , Linhagem Celular Tumoral/enzimologia , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Transfecção
7.
PLoS One ; 9(8): e105231, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25137137

RESUMO

Pleomorphic adenoma is the most common salivary gland neoplasm, and it can be locally invasive, despite its slow growth. This study aimed to establish a novel cell line (AP-1) derived from a human pleomorphic adenoma sample to better understand local invasiveness of this tumor. AP-1 cell line was characterized by cell growth analysis, expression of epithelial and myoepithelial markers by immunofluorescence, electron microscopy, 3D cell culture assays, cytogenetic features and transcriptomic study. Expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) was also analyzed by immunofluorescence and zymography. Furthermore, epithelial and myoepithelial markers, MMPs and TIMPs were studied in the tumor that originated the cell line. AP-1 cells showed neoplastic epithelial and myoepithelial markers, such as cytokeratins, vimentin, S100 protein and smooth-muscle actin. These molecules were also found in vivo, in the tumor that originated the cell line. MMPs and TIMPs were observed in vivo and in AP-1 cells. Growth curve showed that AP-1 exhibited a doubling time of 3.342 days. AP-1 cells grown inside Matrigel recapitulated tumor architecture. Different numerical and structural chromosomal anomalies were visualized in cytogenetic analysis. Transcriptomic analysis addressed expression of 7 target genes (VIM, TIMP2, MMP2, MMP9, TIMP1, ACTA2 e PLAG1). Results were compared to transcriptomic profile of non-neoplastic salivary gland cells (HSG). Only MMP9 was not expressed in both libraries, and VIM was expressed solely in AP-1 library. The major difference regarding gene expression level between AP-1 and HSG samples occurred for MMP2. This gene was 184 times more expressed in AP-1 cells. Our findings suggest that AP-1 cell line could be a useful model for further studies on pleomorphic adenoma biology.


Assuntos
Adenoma Pleomorfo/patologia , Linhagem Celular Tumoral/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Neoplasias das Glândulas Salivares/patologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Adulto , Biomarcadores Tumorais/metabolismo , Aberrações Cromossômicas , Análise Mutacional de DNA , Humanos , Masculino , Transcriptoma
8.
PLoS One ; 9(7): e99017, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25036984

RESUMO

The JAK2V617F mutation is found in the majority of patients with myeloproliferative neoplasms (MPNs). Transgenic expression of the mutant gene causes MPN-like phenotypes in mice. We have produced JAK2V617F mice with p53 null background. Some of these mice developed acute erythroleukemia. From one of these mice, we derived a cell line designated J53Z1. J53Z1 cells were stained positive for surface markers CD71 and CD117 but negative for Sca-1, TER-119, CD11b, Gr-1, F4/80, CD11c, CD317, CD4, CD8a, CD3e, B220, CD19, CD41, CD42d, NK-1.1, and FceR1. Real time PCR analyses demonstrated expressions of erythropoietin receptor EpoR, GATA1, and GATA2 in these cells. J53Z1 cells grew rapidly in suspension culture containing fetal bovine serum with a doubling time of ∼18 hours. When transplanted into C57Bl/6 mice, J53Z1 cells induced acute erythroleukemia with massive infiltration of tumor cells in the spleen and liver. J53Z1 cells were responsive to stimulation with erythropoietin and stem cell factor and were selectively inhibited by JAK2 inhibitors which induced apoptosis of the cells. Together, J53Z1 cells belong to the erythroid lineage, and they may be useful for studying the role of JAK2V617F in proliferation and differentiation of erythroid cells and for identifying potential therapeutic drugs targeting JAK2.


Assuntos
Linhagem Celular Tumoral/enzimologia , Janus Quinase 2/genética , Leucemia Eritroblástica Aguda/patologia , Mutação de Sentido Incorreto , Proteínas de Neoplasias/genética , Mutação Puntual , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/transplante , Cruzamentos Genéticos , Ensaios de Seleção de Medicamentos Antitumorais , Eritropoese/efeitos dos fármacos , Perfilação da Expressão Gênica , Genes p53 , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Humanos , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteínas de Neoplasias/biossíntese , Inibidores de Proteínas Quinases/farmacologia , Baço/patologia
9.
Anal Chem ; 86(14): 7119-27, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24939283

RESUMO

Phospholipase D (PLD) is a critical component of intracellular signal transduction and has been implicated in many important biological processes. It has been observed that there are abnormalities in PLD expression in many human cancers, and PLD is thus recognized as a potential diagnostic biomarker as well as a target for drug discovery. We report for the first time a phospholipid-modified nanoprobe for ratiometric upconversion fluorescence (UCF) sensing and bioimaging of PLD activity. The nanoprobe can be synthesized by a facile one-step self-assembly of a phospholipid monolayer composed of poly(ethylene glycol) (PEG)ylated phospholipid and rhodamine B-labeled phospholipid on the surface of upconversion nanoparticles (UCNPs) NaYF4: 20%Yb, 2%Er. The fluorescence resonance energy transfer (FRET) process from the UCF emission at 540 nm of the UCNPs to the absorbance of the rhodamine B occurs in the nanoprobe. The PLD-mediated hydrolysis of the phosphodiester bond makes rhodamine B apart from the UCNP surface, leading to the inhibition of FRET. Using the unaffected UCF emission at 655 nm as an internal standard, the nanoprobe can be used for ratiometric UCF detection of PLD activity with high sensitivity and selectivity. The PLD activity in cell lysates is also determined by the nanoprobe, confirming that PLD activity in a breast cancer cell is at least 7-fold higher than in normal cell. Moreover, the nanoprobe has been successfully applied to monitoring PLD activity in living cells by UCF bioimaging. The results reveal that the nanoprobe provides a simple, sensitive, and robust platform for point-of-care diagnostics and drug screening in biomedical applications.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Imagem Molecular/métodos , Nanopartículas/química , Fosfolipase D/análise , Fosfolipídeos/química , Linhagem Celular/enzimologia , Linhagem Celular Tumoral/enzimologia , Fluorescência , Humanos , Hidrólise , Imagem Molecular/instrumentação , Polietilenoglicóis/química , Rodaminas/química , Soluções , Itérbio/química , Ítrio/química
10.
Chem Commun (Camb) ; 50(53): 6987-90, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24844612

RESUMO

A simple and novel furanyl acryl conjugated coumarin fluorophore was designed as an effective thioredoxin reductase (TrxR)-responding fluorescent probe by an activity-guided approach. Basically, the α,ß-unsaturated ketone moiety in the probe structure could quench the fluorescence of the coumarin, but upon the covalent modification of TrxR, a significant fluorescence could be generated, which has been confirmed to be obviously selective over Trx, GSH, Cys and DTT.


Assuntos
Cumarínicos/química , Cumarínicos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Corantes Fluorescentes/química , Tiorredoxinas/antagonistas & inibidores , Linhagem Celular Tumoral/enzimologia , Humanos , Iodoacetamida/química , Cetonas/química , Cinética
11.
Braz J Med Biol Res ; 46(7): 634-42, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23903680

RESUMO

Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D) models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer.


Assuntos
Fosfatase Ácida/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neoplasias Pancreáticas/tratamento farmacológico , Esferoides Celulares/efeitos dos fármacos , Antimetabólitos Antineoplásicos/administração & dosagem , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Sobrevivência Celular , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Fluoruracila/administração & dosagem , Humanos , Neoplasias Pancreáticas/enzimologia , Esferoides Celulares/enzimologia , Gencitabina
12.
Braz. j. med. biol. res ; 46(7): 634-642, ago. 2013. graf
Artigo em Inglês | LILACS | ID: lil-682404

RESUMO

Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D) models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer.


Assuntos
Humanos , Fosfatase Ácida/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neoplasias Pancreáticas/tratamento farmacológico , Esferoides Celulares/efeitos dos fármacos , Antimetabólitos Antineoplásicos/administração & dosagem , Sobrevivência Celular , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Fluoruracila/administração & dosagem , Neoplasias Pancreáticas/enzimologia , Esferoides Celulares/enzimologia
13.
Cancer Sci ; 104(10): 1315-22, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23822636

RESUMO

We have recently identified tumor necrosis factor (TNF)-α-induced phosphorylation of epidermal growth factor receptor (EGFR) at Thr-669 and Ser-1046/1047 via ERK and p38 pathways, respectively. In the present study, we investigated the roles of ligand-induced phosphorylation of serine and threonine residues in EGFR-overexpressing MDA-MB-468 breast cancer cells. Epidermal growth factor and heregulin, an ErbB3 ligand, induced the phosphorylation of Thr-669 and Ser-1046/1047. Inversely, constitutive tyrosine phosphorylation of the C-terminal domain, including Tyr-1068, was significantly downregulated on ligand stimulation. Inhibition of the ERK pathway by U0126 blocked ligand-induced Thr-669 phosphorylation as well as Tyr-1068 dephosphorylation. Downregulation of constitutive tyrosine phosphorylation of EGFR in HEK293 cells stably expressing the wild type was abolished by substitution of Thr-669 for Ala. In an asymmetric EGFR homodimer structure, one Thr-669 in the receiver kinase of the dimer was involved in downregulation. Similarly, Thr-669 in an EGFR-ErbB3 heterodimer also participated in tyrosine dephosphorylation. These results indicate that ERK-mediated Thr-669 phosphorylation suppresses constitutive tyrosine phosphosphorylation in the homo- and heterodimer asymmetric conformations of the EGFR.


Assuntos
Receptores ErbB/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/metabolismo , Fosfotreonina/metabolismo , Processamento de Proteína Pós-Traducional , Adenocarcinoma/enzimologia , Neoplasias da Mama/enzimologia , Butadienos/farmacologia , Linhagem Celular Tumoral/enzimologia , Dimerização , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/química , Retroalimentação Fisiológica , Feminino , Humanos , Ligantes , Proteínas de Neoplasias/química , Neuregulina-1/farmacologia , Nitrilas/farmacologia , Fosforilação , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologia , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
14.
Mol Gen Mikrobiol Virusol ; (1): 14-20, 2013.
Artigo em Russo | MEDLINE | ID: mdl-23785785

RESUMO

The DNA polymerase iota (Pol iota), which has some peculiar features and is characterized by an extremely error-prone DNA synthesis, belongs to the group of enzymes preferentially activated by Mn2+ instead of Mg2+. In this work, the effect of Mn2+ on DNA synthesis in cell extracts from a) normal human and murine tissues, b) human tumor (uveal melanoma), and c) cultured human tumor cell lines SKOV-3 and HL-60 was tested. Each group displayed characteristic features of Mn-dependent DNA synthesis. The changes in the Mn-dependent DNA synthesis caused by malignant transformation of normal tissues are described. It was also shown that the error-prone DNA synthesis catalyzed by Pol iota in extracts of all cell types was efficiently suppressed by an RNA aptamer (IKL5) against Pol iota obtained in our work earlier. The obtained results suggest that IKL5 might be used to suppress the enhanced activity of Pol iota in tumor cells.


Assuntos
DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Manganês/farmacologia , Melanoma/enzimologia , Neoplasias Uveais/enzimologia , Animais , Aptâmeros de Nucleotídeos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Transformação Celular Neoplásica/genética , DNA/biossíntese , Relação Dose-Resposta a Droga , Células HL-60/efeitos dos fármacos , Humanos , Melanoma/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Uveais/tratamento farmacológico , DNA Polimerase iota
15.
Toxicol In Vitro ; 27(6): 1719-27, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23669205

RESUMO

The bioactivation of pro-toxicants is the biological process through which some chemicals are metabolized into reactive metabolites. Therefore, in vitro toxicological evaluation should ideally be conducted in cell systems retaining adequate metabolic competency and relevant to the route of exposure. The respiratory tract is the primary route of exposure to inhaled pro-toxicants and lung-derived BEAS-2B cell line has been considered as a potentially suitable model for in vitro toxicology testing. However, its metabolic activity has not been characterized. We performed a gene expression analysis for 41 metabolism-related genes and compared the profile with liver- and lung-derived cell lines (HepaRG, HepG2 and A549). To confirm that mRNA expression was associated with the corresponding enzyme activity, we used a series of metabolic substrates of CYPs (CYP1A1/1B1, CYP1A2, CYP2A6/2A13 and CYP2E1) known to bioactivate inhaled pro-toxicants. CYP activities were compared between BEAS-2B, HepaRG, HepG2, and A549 cells and published literature on primary bronchial epithelium cells (HBEC). We found that in contrast to HBEC, BEAS-2B and A549 have limited CYP activity which was in agreement with their CYP gene expression profile. Control cell lines such as HepG2 and HepaRG were metabolically active for the tested CYPs. We recommend that similar strategies can be used to select suitable cell systems in the context of pro-toxicant assessment.


Assuntos
Linhagem Celular Tumoral/enzimologia , Linhagem Celular/enzimologia , Sistema Enzimático do Citocromo P-450/genética , Regulação Enzimológica da Expressão Gênica , Sobrevivência Celular/efeitos dos fármacos , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Perfilação da Expressão Gênica , Humanos , Pulmão/citologia , Dibenzodioxinas Policloradas/toxicidade , Reação em Cadeia da Polimerase , Testes de Toxicidade
17.
Methods Mol Biol ; 981: 211-27, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23381865

RESUMO

The effect of histone deacetylases (HDACs) on normal and aberrant gene expression has been studied widely, making these enzymes interesting targets for the treatment of cancer and other diseases. In this chapter, we present in vitro assays that are commonly used to detect HDAC activity that do not rely on radioactive substrates and are amenable for high-throughput testing in microtiter plates. The major focus is on in vitro screening, but we also provide protocols to monitor HDAC activity from cancer cells and peripheral white blood cells. We will discuss the advantages and drawbacks of the respective protocols and give general hints and suggestions that are valuable to obtain reliable and reproducible results.


Assuntos
Bioensaio/métodos , Linhagem Celular Tumoral/enzimologia , Histona Desacetilases/metabolismo , Leucócitos/enzimologia , Acetilação , Polarização de Fluorescência , Histona Desacetilases/genética , Histonas/metabolismo , Humanos
18.
Exp Hematol ; 41(2): 172-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23085464

RESUMO

Matrix metalloprotease-9 (MMP9) plays a critical role in acute myeloid leukemia (AML) by increasing the invasive properties of malignant myeloblasts. The role of this enzyme in high-risk myelodysplastic diseases (MDS) and the effect of azacitidine on its expression in MDS and AML have not been studied in detail. In this work, we have analyzed the effect of different concentrations of azacitidine in two well-established, MDS-derived, acute myeloid leukemic cell lines: MOLM-13 and SKM-1. We have demonstrated that 1 µmol/L azacitidine decreases MMP9 DNA methylation levels and that this is correlated with a significant increase in messenger RNA expression in both cell lines. Surprisingly, changes in protein levels were minor. This paradoxic effect is explained by the drug-dependent induction of apoptosis that reduces the amount of active secreting cells. A balance between induced expression and apoptosis was established at an azacitidine concentration of 0.2 µmol/L in MOLM-13 cells. This dose significantly increased the invasive capacity of viable cells, as measured in the Matrigel assay. To evaluate the clinical relevance of this observation, we have examined the effect of azacitidine on MMP9 expression in bone marrow from five patients with MDS, with the finding that this drug significantly increased MMP9 protein levels in all analyzed patients after six cycles of treatment. Based on these results, we conclude that azacitidine increases MMP9 expression and may enhance invasiveness in vitro. Because all five patients relapsed, these findings might explain, at least partially, the clinical failure of the drug and the progression to a more aggressive disease.


Assuntos
Anemia Refratária com Excesso de Blastos/tratamento farmacológico , Antimetabólitos Antineoplásicos/farmacologia , Antimetabólitos/uso terapêutico , Azacitidina/farmacologia , Leucemia Monocítica Aguda/patologia , Leucemia Mielomonocítica Aguda/patologia , Metaloproteinase 9 da Matriz/biossíntese , Proteínas de Neoplasias/biossíntese , Idoso , Idoso de 80 Anos ou mais , Anemia Refratária com Excesso de Blastos/enzimologia , Anemia Refratária com Excesso de Blastos/patologia , Antimetabólitos/efeitos adversos , Apoptose/efeitos dos fármacos , Azacitidina/efeitos adversos , Azacitidina/uso terapêutico , Catálise/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Metilação de DNA/efeitos dos fármacos , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Indução Enzimática/efeitos dos fármacos , Feminino , Humanos , Masculino , Metaloproteinase 9 da Matriz/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Segunda Neoplasia Primária/tratamento farmacológico , Segunda Neoplasia Primária/enzimologia , Segunda Neoplasia Primária/patologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Risco
19.
Br J Haematol ; 160(2): 177-87, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23157224

RESUMO

Aberrant JAK2 signalling plays an important role in the aetiology of myeloproliferative neoplasms (MPNs). JAK2 inhibitors, however, do not readily eliminate neoplastic MPN cells and thus do not induce patient remission. Further understanding JAK2 signalling in MPNs may uncover novel avenues for therapeutic intervention. Recent work has suggested a potential role for cellular cholesterol in the activation of JAK2 by the erythropoietin receptor and in the development of an MPN-like disorder in mice. Our study demonstrates for the first time that the MPN-associated JAK2-V617F kinase localizes to lipid rafts and that JAK2-V617F-dependent signalling is inhibited by lipid raft disrupting agents, which target membrane cholesterol, a critical component of rafts. We also show for the first time that statins, 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors, widely used to treat hypercholesterolaemia, induce apoptosis and inhibit JAK2-V617F-dependent cell growth. These cells are more sensitive to statin treatment than non-JAK2-V617F-dependent cells. Importantly, statin treatment inhibited erythropoietin-independent erythroid colony formation of primary cells from MPN patients, but had no effect on erythroid colony formation from healthy individuals. Our study is the first to demonstrate that JAK2-V617F signalling is dependent on lipid rafts and that statins may be effective in a potential therapeutic approach for MPNs.


Assuntos
Janus Quinase 2/fisiologia , Microdomínios da Membrana/fisiologia , Mutação de Sentido Incorreto , Transtornos Mieloproliferativos/enzimologia , Mutação Puntual , Transdução de Sinais/efeitos dos fármacos , Sinvastatina/farmacologia , beta-Ciclodextrinas/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/enzimologia , Colesterol/análise , Colesterol/fisiologia , Ensaio de Unidades Formadoras de Colônias , Avaliação Pré-Clínica de Medicamentos , Células Precursoras Eritroides/efeitos dos fármacos , Células Precursoras Eritroides/enzimologia , Humanos , Janus Quinase 2/genética , Células K562/efeitos dos fármacos , Células K562/enzimologia , Leucemia Eritroblástica Aguda/enzimologia , Leucemia Eritroblástica Aguda/patologia , Leucemia Megacarioblástica Aguda/enzimologia , Leucemia Megacarioblástica Aguda/patologia , Células Progenitoras de Megacariócitos/efeitos dos fármacos , Células Progenitoras de Megacariócitos/enzimologia , Lipídeos de Membrana/fisiologia , Microdomínios da Membrana/efeitos dos fármacos , Transtornos Mieloproliferativos/sangue , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Fator de Transcrição STAT5/metabolismo
20.
Cancer Lett ; 325(2): 220-6, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-22796605

RESUMO

Cytokines present in the tumor microenvironment can promote the invasiveness and metastatic potential of cancer cells. We therefore investigated the effects of interleukin-1 beta (IL-1B) and transforming growth factor beta-3 (TGFB3) on the non-small cell lung carcinoma (NSCLC) cell line A549. We found that these cytokines synergistically activated matrix metalloproteinase (MMP)-1, MMP-3, and MMP-10 gene expression in these cells through mitogen-activated protein kinase (MAPK)-dependent pathways. Consistent with this, both cytokines stimulated epithelial to mesenchymal transition and MAPK-dependent invasion through Matrigel™. These studies identify IL-1B and TGFB3 as pro-invasive factors in NSCLC and potential therapeutic targets for tumor progression.


Assuntos
Adenocarcinoma/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Interleucina-1beta/farmacologia , Neoplasias Pulmonares/patologia , Metaloproteinase 10 da Matriz/biossíntese , Metaloproteinase 1 da Matriz/biossíntese , Metaloproteinase 3 da Matriz/biossíntese , Proteínas de Neoplasias/biossíntese , Fator de Crescimento Transformador beta3/farmacologia , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/enzimologia , Linhagem Celular Tumoral/patologia , Colágeno , Combinação de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Indução Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Renais/patologia , Laminina , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 10 da Matriz/genética , Metaloproteinase 3 da Matriz/genética , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Inibidores de Proteínas Quinases/farmacologia , Proteoglicanas
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