Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
2.
Phys Rev Lett ; 129(22): 222501, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493444

RESUMO

The Cryogenic Underground Observatory for Rare Events (CUORE) at Laboratori Nazionali del Gran Sasso of INFN in Italy is an experiment searching for neutrinoless double beta (0νßß) decay. Its main goal is to investigate this decay in ^{130}Te, but its ton-scale mass and low background make CUORE sensitive to other rare processes as well. In this Letter, we present our first results on the search for 0νßß decay of ^{128}Te, the Te isotope with the second highest natural isotopic abundance. We find no evidence for this decay, and using a Bayesian analysis we set a lower limit on the ^{128}Te 0νßß decay half-life of T_{1/2}>3.6×10^{24} yr (90% CI). This represents the most stringent limit on the half-life of this isotope, improving by over a factor of 30 the previous direct search results, and exceeding those from geochemical experiments for the first time.


Assuntos
Granisetron , Meia-Vida , Teorema de Bayes
3.
Phys Rev Lett ; 126(17): 171801, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988435

RESUMO

We measured two-neutrino double beta decay of ^{130}Te using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: T_{1/2}^{2ν}=7.71_{-0.06}^{+0.08}(stat)_{-0.15}^{+0.12}(syst)×10^{20} yr. This measurement is the most precise determination of the ^{130}Te 2νßß decay half-life to date.

4.
Phys Rev Lett ; 124(12): 122501, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32281829

RESUMO

We report new results from the search for neutrinoless double-beta decay in ^{130} Te with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10^{-2} counts/(keV kg yr)) in the 0νßß decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×10^{25} yr. We find no evidence for 0νßß decay and set a 90% credibility interval Bayesian lower limit of 3.2×10^{25} yr on the ^{130} Te half-life for this process. In the hypothesis that 0νßß decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.

5.
Eur Phys J C Part Fields ; 83(6): 467, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37303462

RESUMO

The ICARUS collaboration employed the 760-ton T600 detector in a successful 3-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous νe appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV2. After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operations collecting the first neutrino events from the booster neutrino beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022. The first goal of the ICARUS data taking will be a study to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short-Baseline Near Detector, within the Short-Baseline Neutrino program. In this paper, the main activities carried out during the overhauling and installation phases are highlighted. Preliminary technical results from the ICARUS commissioning data with the BNB and NuMI beams are presented both in terms of performance of all ICARUS subsystems and of capability to select and reconstruct neutrino events.

6.
Biochim Biophys Acta ; 562(3): 495-503, 1979 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-454613

RESUMO

1. Rat liver microsomes isolated at 6 and 12 h of poisoning with 3 x LD50 (0.3 microgram/100 g body wt.) of modeccin, the toxin of Adenia digitata, have a decreased capacity of protein synthesis in vitro. 2. A similar decrease of protein synthesis is observed with polysomes at 6 h of poisoning. Experiments with recombined ribosomal subunits demonstrate that this is due to inactivation of the 60 S ribosomal subunit. 3. At 6 h of poisoning there is a marked vesiculation and degranulation of the hepatocyte rough endoplasmic reticulum, which is completely fragmented at 24 h of poisoning. Hepatocyte mitochondria are swollen at 6 h and shrunk at 24 h of poisoning. 4. It is concluded that modeccin penetrates inside hepatocytes in vivo, and damages ribosomes in the same manner as it does in vitro. However, mitochondrial damage indicates that ribosomes may not be the only target of modeccin in vivo.


Assuntos
Lectinas/farmacologia , Ribossomos/efeitos dos fármacos , Toxinas Biológicas/farmacologia , Animais , Feminino , Fígado/efeitos dos fármacos , Fígado/patologia , Microssomos Hepáticos/efeitos dos fármacos , Biossíntese Peptídica , Fenilalanina , Lectinas de Plantas , Plantas Tóxicas , Polirribossomos/efeitos dos fármacos , Biossíntese de Proteínas , Ratos , Proteínas Inativadoras de Ribossomos Tipo 2
7.
Exp Hematol ; 17(7): 755-9, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2753083

RESUMO

The antiproliferative effect of saporin 6 (SO6), a ribosome-inactivating protein (RIP) purified from the seeds of Saponaria officinalis has been tested on three leukemic cell lines (K562, U937, and HL60), human normal bone marrow, and peripheral blood hemopoietic progenitor cells from normal subjects. In leukemic cell lines, SO6 appeared much more effective against erythrocytic than against monocytic and promyelocytic leukemic cells, as shown by protein synthesis assays carried out after up to 72 h of culture. Among the normal hemopoietic progenitor cells, erythroid burst-forming units were the most affected, with results similar to those observed in the erythroid leukemic cell line, both in treated and in pretreated cultures, with strong damage after 24 h of exposure to SO6. On the other hand, granulocyte-macrophage colony-forming units (CFU-GM) from bone marrow were significantly more affected than the myeloid leukemic cell lines after permanent treatment with the inhibitor, the damage being significantly lower after an exposure of 24 h. CFU-GM from peripheral blood and megakaryocyte CFU showed an intermediate sensitivity after 24 h of exposure to SO6, similar to that of the other normal precursors after permanent treatment with the drug.


Assuntos
Inibidores do Crescimento , Células-Tronco Hematopoéticas/efeitos dos fármacos , Imunotoxinas , N-Glicosil Hidrolases , Proteínas de Plantas/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Células da Medula Óssea , Divisão Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , Humanos , Técnicas In Vitro , Biossíntese de Proteínas , Proteínas Inativadoras de Ribossomos Tipo 1 , Ribossomos/efeitos dos fármacos , Saporinas
8.
FEBS Lett ; 392(1): 16-20, 1996 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-8769306

RESUMO

The single-chain ribosome-inactivating proteins (scRIPs) from plant origin are antiviral and antiproliferative agents employed in the preparation of immunotoxins. Similarly to the A-chains of ricin, sc-RIPs act as rRNA N-glycosidases. We demonstrate here that dianthin 30, saporin 6 and gelonin exert a specific nuclease activity on supercoiled DNA. Four specific sites of cleavage introduced by dianthin 30 and by saporin 6 and two specific sites of cleavage introduced by gelonin have been identified and mapped in pBR322.


Assuntos
Antivirais/metabolismo , DNA Super-Helicoidal/metabolismo , Desoxirribonucleases/metabolismo , N-Glicosil Hidrolases , Proteínas de Plantas/metabolismo , Inibidores da Síntese de Proteínas/metabolismo , Sítios de Ligação , DNA Bacteriano/metabolismo , DNA Viral/metabolismo , Concentração de Íons de Hidrogênio , Imunotoxinas , Cloreto de Magnésio/farmacologia , Mapeamento por Restrição , Proteínas Inativadoras de Ribossomos Tipo 1 , Ribossomos/metabolismo , Saporinas , Cloreto de Sódio/farmacologia , Temperatura
9.
Eur J Cancer ; 34(5): 724-30, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9713281

RESUMO

A new human cancer cell line was established from a metastatic lesion of a small cell lung carcinoma (SCLC-R1) and maintained in continuous culture with a doubling time of 62 h. The SCLC-R1 line, whose ultrastructural features are presented, showed a diploid DNA content, a translocation involving chromosome 16 [t(16;?)(q24;?)] and noticeable deletions in the FHIT (fragile histidine triad) region in the short arm of chromosome 3 [del(3)(p14)] and in the telomeric region of the short arm of chromosome 12 [del(12)(p13)]. The involvement of 12p in metastatic small cell lung cancer is reported here for the first time. No amplification or rearrangements were evident in the c-myc, L-myc, N-myc, int-2, c-erbB-2, H-ras, K-ras, c-mos, and hst-1 genes by Southern blot analysis. Wild-type p53, RB, K-ras and H-ras genes were evident by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis. The neuron specific enolase (NSE) level was much higher in the cell line's cytosol than in the patient's serum and the cell line also had high expression of chromogranin A and cytokeratin 19. SCLC-R1 cells were sensitive to cisplatin, carboplatin and doxorubicin. The clinical history of the patient from whom the cell line was derived is reported. The characteristics of this new cell line indicate it to be a useful experimental model to investigate lung cancer biology and anticancer drug response.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma de Células Pequenas/genética , Aberrações Cromossômicas , Neoplasias Pulmonares/genética , Células Tumorais Cultivadas/efeitos dos fármacos , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Pequenas/tratamento farmacológico , Carcinoma de Células Pequenas/metabolismo , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Diploide , Deleção de Genes , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Masculino , Proteínas Proto-Oncogênicas/metabolismo , Translocação Genética , Células Tumorais Cultivadas/patologia
10.
J Cancer Res Clin Oncol ; 122(4): 237-42, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8601577

RESUMO

We established a novel cancer cell line (MAST) from the ascitic fluid of a metastatic infiltrating ductal carcinoma of the breast. The epithelial and neoplastic nature of the MAST cells was confirmed by ultrastructural analysis. The cell line was maintained as a monolayer with a doubling time of about 68 h, and it possessed an abnormal karyotype with a modal chromosome number of 60, a trisomy of chromosome 18 and other unidentified rearranged chromosomes. Among the markers consistently found in MAST metaphases, we noted a t(14; 14) and a very large subtelocentric, a large satellited acrocentric and a very large submetacentric chromosome with striking fluorescent bands. Immunoenzymatic assay demonstrated that the MAST cell line was positive for estrogen and progesterone receptors. The in vitro drug-sensitivity assay showed a marked resistance of the cell line to 5-fluorouracil and 4-hydroperoxycyclophosphamide and a moderate resistance to etoposide and 4'-epidoxorubicin. The molecular analysis showed a four-to sixfold amplification of the c-myc gene and no amplification or rearrangement of the int-2, c-erbB-2, c-Ha-ras, c-mos and hst-1 genes.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Células Tumorais Cultivadas , Adulto , Ascite , Biomarcadores Tumorais/análise , Divisão Celular , Bandeamento Cromossômico , DNA de Neoplasias/genética , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Genes myc , Humanos , Microscopia Eletrônica
11.
Cancer Genet Cytogenet ; 105(1): 43-9, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9689929

RESUMO

A new cancer cell line (KKP) was established from an ascitic effusion of an advanced gastric adenocarcinoma, intestinal type. The line has been maintained in continuous monolayer culture with a doubling time of 48 hours for more than 2 years. KKP cells, whose ultrastructural features are presented, showed an aneuploid DNA content, a modal number of 53 chromosomes, and the presence of one double minute chromosome. The karyotype showed trisomies of chromosomes 7, 12, 13, and 14, tetrasomy of chromosome 18, a reciprocal translocation [t(1;20)(q21;p11.2)], and a [t(4;?)] rearrangement. No amplification or rearrangements were evident in the c-MYC, c-ERB B2, H-RAS, INT-2, HST-1, c-MOS, and K-RAS genes, whereas somatic rearrangements were present in the sequences corresponding to c-MET and cyclin E genes by Southern blotting analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of P53 and RB genes did not reveal alterations or point mutations in the SSCP pattern of conformers. The chemosensitivity pattern assay of the KKP cell line indicated that it was sensitive to cisplatin, etoposide, and doxorubicin and resistant to 4'-hydroperoxycyclophosphamide. The clinical history of the patient from whom the cell line was derived is reported and compared with the results observed in the cell line in vitro. High levels of the tumor-associated antigens CEA (carcinoembryonic antigen) and CA19-9 were evident in the KKP cytosol, whereas the KKP spent culture medium maintained the same low levels of CEA and CA 19-9 found in the patient's serum. This new cell line may represent a useful tool for studying the biology of gastric cancer and for planning new therapeutic approaches.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Adenocarcinoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/tratamento farmacológico , Células Tumorais Cultivadas
12.
Cancer Genet Cytogenet ; 107(1): 11-20, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9809028

RESUMO

Two human cancer cell lines were established from metastatic lesions of an adenocarcinoma (RAL) and a squamous cell (CAEP) carcinoma of the lung. The clinical histories of the patients from whom the cell lines were derived are reported. The lines were maintained in continuous culture with doubling times of 65 (RAL) and 50 (CAEP) hours. The RAL and CAEP cell lines, whose morphology and ultrastructural features are presented, showed extensively rearranged karyotypes with modal number of 85 (RAL) and 98 (CAEP). In particular, chromosome 2 pentasomy and several clonal markers were evident in the RAL cells, whereas a telomeric deletion of chromosome 1, del (1)(q32), was observed in the CAEP cells. The morphologic data were confirmed by high expression of specific antigens for each histotype. A marked positivity of the neuron-specific enolase (NSE) levels was evident by immunoenzymatic assays in the cell lines cytosol with respect to those present in the respective patient's sera. No amplification or rearrangements were evident in the CMYC, LMYC, NMYC, INT-2, ERBB2, HRAS, KRAS, MOS, HST-1 genes by Southern blotting analysis in each cell line. Point mutations in exon 1 of KRAS and in exon 7 of TP53 were evident by polymerase chain reaction (PCR)-DNA sequencing in the RAL cell line, whereas no alterations were present in the HRAS and RB genes. The four genes studied did not show point mutations in the CAEP cell line. The RAL cell line was resistant to all the drugs tested, whereas the CAEP cells were sensitive to vinblastine. These cell lines may represent useful experimental models to investigate lung cancer biology and anticancer drug response.


Assuntos
Adenocarcinoma/genética , Carcinoma de Células Escamosas/genética , Neoplasias Pulmonares/genética , Células Tumorais Cultivadas , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Biomarcadores Tumorais/metabolismo , Antígeno Carcinoembrionário/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Marcadores Genéticos , Humanos , Cariotipagem , Queratinas/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Fosfopiruvato Hidratase/metabolismo
13.
Melanoma Res ; 3(5): 363-7, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8292894

RESUMO

The inhibitory effect of saporin 6, a single-chain ribosome-inactivating protein (sc-RIP) purified from the seeds of Saponaria officinalis, on the proliferation of human primary (MeWo, WM 164, SK MEL 28, MEM), cloned (MEM A9, A12, A13) and metastatic (M14) melanoma cells has been tested by protein synthesis and colony formation assays in vitro. Results indicate a marked difference in the sensitivity of primary and metastatic cells to the action of saporin 6, the latter being significantly more affected, both in treated and in pretreated cultures, with a high and specific response evident after 24 h of treatment and progressively increasing up to 72 h of culture with the drug (IC50 = 0.82 microgram/ml). This effect, which was dose-dependent in exponentially growing cells, was partially reversed upon removal of the inhibitor from the culture medium. No inhibitory effect was evident in the MeWo primary cells at the highest saporin 6 concentration used: the p170 glycoprotein-mediated mechanism is not involved in such a resistance pathway.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Imunotoxinas , Melanoma/tratamento farmacológico , Melanoma/secundário , N-Glicosil Hidrolases , Proteínas de Plantas/farmacologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Humanos , Cinética , Melanoma/metabolismo , Proteínas de Neoplasias/biossíntese , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco
14.
Anticancer Res ; 11(2): 1007-11, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2064307

RESUMO

The antiproliferative activity of Saporin 6, a Ribosome-inactivating protein purified from the seeds of Saponaria officinalis has been tested on human breast cancer cells in vitro by the analysis (a) of colony formation in cells from surgical specimens from 27 patients bearing primary breast cancer and (b) of protein synthesis inhibition in the MCF/7 cell line. Results indicate a very high sensitivity of breast cancer cells from most patients to a short-term treatment with Saporin 6 at concentrations (10(-9) M), until now found effective only in acellular systems or after conjugation with monoclonal antibodies. On the contrary, the treatment of the human cell line MCF/7 indicate a very reduced sensitivity compared to fresh human neoplastic cells, with the necessity of a long lag for the effect to begin.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/patologia , Divisão Celular/efeitos dos fármacos , Imunotoxinas , N-Glicosil Hidrolases , Proteínas de Plantas/farmacologia , Ribossomos/efeitos dos fármacos , Linhagem Celular , Epirubicina/farmacologia , Feminino , Humanos , Metástase Linfática , Menopausa , Proteínas de Neoplasias/biossíntese , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/efeitos dos fármacos , Ensaio Tumoral de Célula-Tronco
15.
Anticancer Res ; 15(3): 773-6, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7645957

RESUMO

The ability of Lonidamine (LND), an energolytic derivative of indazole-carboxylic acid, to modulate the antiproliferative effect of the single-chain ribosome-inactivating protein Saporin 6 (SO 6) was investigated in the human MAST breast cancer cell line, recently established from an ascitic effusion of a ductal carcinoma, by analysis of protein synthesis inhibition and of colony formation in vitro. Different schedules were tested varying with regard to time of exposure (0-24 h), concentration of the drugs (0.01- > 10 micrograms/ml SO 6; 25-100 micrograms/ml LND) and sequence of administration (LND- > SO 6; SO 6- > LND; SO 6+LND). Results indicate that the marginal activity exerted here by each drug when tested independently is highly potentiated by the combination treatments, the cytotoxicity becoming significantly greater than that expected from an additive effect between the two drugs. In particular, a strong synergistic effect is obtained when SO 6 preceedes LND, with a reduction of the SO 6 IC 50 from 1.3 x 10(-7) M to 2.6 x 10(-9) M.


Assuntos
Antineoplásicos/toxicidade , Imunotoxinas , Indazóis/toxicidade , N-Glicosil Hidrolases , Proteínas de Plantas/toxicidade , Antineoplásicos Fitogênicos/toxicidade , Neoplasias da Mama , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Metástase Neoplásica , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco
16.
Anticancer Res ; 7(2): 151-4, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3592627

RESUMO

A DNA synthesis-inhibiting protein (for which the term tulipin is proposed) was isolated from the bulbs of Tulipa sp. The yield ranged from 3.4 to 4.1 per cent of total protein content of the crude extract. Mr, isoelectric point, neutral and amino sugar and amino acid composition were determined. Inhibition of DNA synthesis varied in intact cells according to the cellular types studied, with a minimum ID 50% (concentration giving 50% inhibition) of 400 ng/ml in neuroblastoma cells. The effect was reversible. No effect was obtained in cell-lysate. RNA and protein synthesis were unaffected. The acute toxicity, evaluated in Swiss mice, gave an LD of 6.1 mg/kg body wt. Results of electron microscopy are also given. A second protein, called tulipin 2, has been isolated and partially characterized.


Assuntos
DNA/biossíntese , Glicoproteínas/farmacologia , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Aminoácidos/análise , Animais , Células Cultivadas , Glicoproteínas/isolamento & purificação , Glicoproteínas/toxicidade , Humanos , Melanoma/patologia , Camundongos , Neuroblastoma , Proteínas de Plantas/toxicidade
17.
Oncogene ; 29(7): 978-91, 2010 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-19935718

RESUMO

The c-Jun N-terminal kinase (JNK) has been shown to mediate tamoxifen-induced apoptosis in breast cancer cells. However, the downstream mediators of the JNK pathway linking tamoxifen to effectors of apoptosis have yet to be identified. In this study, we analysed whether c-Jun, the major nuclear target of JNK, has a role in tamoxifen-induced apoptosis of SkBr3 breast cancer cells. We show that before DNA fragmentation and caspase 3/7 activation, cytotoxic concentrations of 4-hydroxytamoxifen (OHT) induced JNK-dependent phosphorylation of c-Jun at JNK sites earlier shown to regulate c-Jun-mediated apoptosis. In addition, OHT induced ERK-dependent expression of c-Fos and transactivation of an AP-1-responsive promoter. In particular, the ectopic expression of dominant-negative constructs blocking either AP-1 activity or c-Jun N-terminal phosphorylation prevented DNA fragmentation after OHT treatment. Furthermore, both c-Fos expression and c-Jun N-terminal phosphorylation preceded OHT-dependent activation of caspase 3-7 in different types of tamoxifen-sensitive cancer cells, but not in OHT-resistant LNCaP prostate cancer cells. Taken together, our results indicate that the c-Jun/c-Fos AP-1 complex has a pro-apoptotic role in OHT-treated cancer cells and suggest that pharmacological boosts of c-Jun activation may be useful in a combination therapy setting to sensitize cancer cells to tamoxifen-mediated cell death.


Assuntos
Neoplasias da Mama/patologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , Tamoxifeno/análogos & derivados , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Especificidade de Órgãos , Fosforilação , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores de Estrogênio/análise , Especificidade por Substrato , Tamoxifeno/farmacologia , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional
20.
Teratog Carcinog Mutagen ; 9(2): 75-81, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2568023

RESUMO

The cytotoxic and mutagenic effects of the fungicides mancozeb and thiram were studied using human peripheral blood lymphocytes cultured in vitro with or without an S-9 mix microsomal metabolizing system. The results obtained suggested that the chemicals caused dose-dependent inhibition of thymidine uptake and unscheduled DNA synthesis on both resting and proliferating lymphocytes in the absence of the S-9 mix. In the presence of the S-9 mix, only thiram showed mutagenic activity by eliciting unscheduled DNA synthesis and a significantly higher frequency of sister chromatid exchanges than did controls.


Assuntos
Dano ao DNA , Linfócitos/efeitos dos fármacos , Maneb/toxicidade , Mutagênicos , Tiocarbamatos/toxicidade , Tiram/toxicidade , Zineb/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Replicação do DNA/efeitos dos fármacos , Humanos , Troca de Cromátide Irmã/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA