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1.
Ann Oncol ; 32(6): 787-800, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33746047

RESUMO

BACKGROUND: Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies. PATIENTS AND METHODS: Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients). RESULTS: A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality. CONCLUSIONS: Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies. CLINICAL TRIAL IDENTIFIER: NCT04354701.


Assuntos
COVID-19 , Neoplasias , Idoso , Teste para COVID-19 , Feminino , Humanos , Masculino , Neoplasias/tratamento farmacológico , Neoplasias/epidemiologia , Pandemias , SARS-CoV-2
2.
Blood Cancer J ; 5: e338, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26275080

RESUMO

This phase 2 trial was designed to evaluate ixazomib, an orally bioavailable proteasome inhibitor, in patients with myeloma who have limited prior exposure to bortezomib. Thirty-three patients with relapsed multiple myeloma were enrolled. Ixazomib was given at 5.5 mg weekly for 3 of 4 weeks. Dexamethasone was added for lack of a minor response (MR) by end of cycle 2 or lack of a partial response (PR) by end of cycle 4 or for disease progression at any time. Median age was 69 years; patients had a median of two prior therapies (range 1-7). A grade 3 or 4 adverse event considered at least possibly related to drug was seen in 19 (59%) and 6 (19%) patients, respectively. The most common adverse events were thrombocytopenia, fatigue, nausea and diarrhea. Dexamethasone was initiated in 22 (67%) patients, 17 for not reaching the desired response and 5 for progression. Response (⩾PR) to single agent was seen in five patients within four cycles of therapy including three patients with PR, one patient with complete response (CR) and one patient with stringent CR. Six additional patients with either an MR (2) or SD (4) achieved a PR after addition of dexamethasone, translating to an overall response rate of 34%.


Assuntos
Antineoplásicos/uso terapêutico , Compostos de Boro/administração & dosagem , Glicina/análogos & derivados , Mieloma Múltiplo/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Compostos de Boro/efeitos adversos , Dexametasona/administração & dosagem , Intervalo Livre de Doença , Feminino , Glicina/administração & dosagem , Glicina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Recidiva , Resultado do Tratamento
5.
Mult Scler ; 13(7): 941-4, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17881403

RESUMO

Glatiramer acetate (GA), a well tolerated immunomodulatory treatment for relapsing-remitting multiple sclerosis (RR-MS), consists of a 4-amino acid polymer that mimics the myelin basic protein (MBP). We report the first case of biopsy-proven erythema nodosum (EN) in a patient presenting RR-MS under GA treatment. Comprehensive exams were negative in the search of the etiology of EN, which spontaneously resolved despite treatment continuation. GA treatment is known to generate reactive polyclonal antibodies that can cross-react with myelin epitopes, like MBP. These antibodies may also be implicated in allergenic reactions and auto-immune adverse events, such as anaphylactic shock, lymphadenopathy, livedo-like dermatitis, or lymphocytic infiltration. EN is an unspecific skin reaction occurring in several disorders and induced by many treatments. As EN can result from a polyclonal antibody response or type I hypersensitivity mechanisms, we hypothesize that GA treatment could be responsible for the occurrence of EN.


Assuntos
Eritema Nodoso/induzido quimicamente , Eritema Nodoso/patologia , Imunossupressores/efeitos adversos , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Peptídeos/efeitos adversos , Anticorpos , Biópsia , Eritema Nodoso/imunologia , Feminino , Acetato de Glatiramer , Humanos , Imunossupressores/imunologia , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/imunologia , Peptídeos/imunologia
6.
Oncogene ; 26(1): 91-101, 2007 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-16799637

RESUMO

The t(8;21) chromosomal translocation that generates the fusion oncoprotein RUNX1-ETO predominates in leukemia patients of the French-American-British (FAB) class M2 subtype. The oncoprotein has the capacity to promote expansion of hematopoietic stem/progenitor cells and induces leukemia in association with other genetic alterations. Here, we show that RUNX1-ETO undergoes degradation in response to treatment with histone deacetylase inhibitors, one of which, depsipeptide (DEP), is currently undergoing phase II clinical testing in a variety of malignancies. These compounds induce turnover of RUNX1-ETO without affecting the stability of RUNX1-ETO partner proteins. In addition, RUNX1-ETO physically interacts with heat shock protein 90 (HSP90). DEP treatment interrupts the association of RUNX1-ETO with HSP90 and induces proteasomal degradation of RUNX1-ETO. DEP and the HSP90 antagonist 17-allylamino-geldanamycin (17-AAG) both triggered RUNX1-ETO degradation, but without any additive or cooperative effects. These findings may stimulate the development of more rational and effective approaches for treating t(8;21) patients using histone deacetylase inhibitors or HSP90 inhibitors.


Assuntos
Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Translocação Genética , Linhagem Celular Tumoral , Humanos , Hidrólise , Imunoprecipitação , Proteína 1 Parceira de Translocação de RUNX1
7.
J Nucl Med Technol ; 29(3): 137-42; quiz 148-50, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11564836

RESUMO

OBJECTIVES: The objectives of this article are to provide the reader with (a) a brief discussion of actual, perceived, and acceptable risks associated with radiation exposure; (b) a basic review of radiation protection units and a discussion as to how these units are used to estimate risk associated with occupational radiation exposure; (c) a summary of radiation doses required for specific human biologic responses and a comparison of relative doses encountered in a variety of clinical situations; and (d) a practical approach to discussing relative risks associated with medical radiation exposures when patients inquire.


Assuntos
Medicina Nuclear , Exposição Ocupacional , Doses de Radiação , Tecnologia Radiológica , Anormalidades Induzidas por Radiação/etiologia , Humanos , Lesões por Radiação/etiologia , Lesões por Radiação/prevenção & controle , Proteção Radiológica , Fatores de Risco
8.
Mol Cell ; 8(1): 105-13, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11511364

RESUMO

Previous work has shown that the Myc transcription factor induces transcription of the E2F1, E2F2, and E2F3 genes. Using primary mouse embryo fibroblasts deleted for individual E2F genes, we now show that Myc-induced S phase and apoptosis requires distinct E2F activities. The ability of Myc to induce S phase is impaired in the absence of either E2F2 or E2F3 but not E2F1 or E2F4. In contrast, the ability of Myc to induce apoptosis is markedly reduced in cells deleted for E2F1 but not E2F2 or E2F3. From this data, we propose that the induction of specific E2F activities is an essential component in the Myc pathways that control cell proliferation and cell fate decisions.


Assuntos
Apoptose/fisiologia , Proteínas de Ciclo Celular/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fase S/fisiologia , Fatores de Transcrição/metabolismo , Adenoviridae/genética , Animais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Fator de Transcrição E2F3 , Fator de Transcrição E2F4 , Fibroblastos/fisiologia , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética , Transfecção
9.
Am J Physiol Renal Physiol ; 281(1): F91-F102, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11399650

RESUMO

Signaling via release of Ca2+ from intracellular stores is mediated by several systems, including the inositol 1,4,5-trisphosphate (IP3) and cADP-ribose (cADPR) pathway. We recently discovered a high capacity for cADPR synthesis in rat glomeruli and cultured mesangial cells (MC). We sought to determine whether 1) cADPR synthesis in MC is regulated by cytokines and hormones, 2) ryanodine receptors (RyRs) are expressed in MC, and 3) Ca2+ is released through RyRs in response to cADPR. We found that ADP-ribosyl cyclase, a CD38-like enzyme that catalyzes cADPR synthesis, is upregulated in MC by tumor necrosis factor-alpha, interleukin-1beta, and all-trans retinoic acid (atRA). [3H]ryanodine binds to microsomal fractions from MC with high affinity in a Ca2+-dependent manner; binding is enhanced by specific RyR agonists and blocked by ruthenium red and cADPR. Western blot analysis confirmed the presence of RyR in MC. Release of 45Ca2+ from MC microsomes was stimulated by cADPR; release was blocked by ruthenium red and 8-bromo-cADPR. ADPR (non-cyclic) was without effect. In MC, TNF-alpha and atRA amplified the increment of cytoplasmic Ca2+ elicited by vasopressin. We conclude that MC possess elements of a novel ADP-ribosyl cyclase-->cADPR-->RyR-->Ca2+-release signaling pathway subject to regulation by proinflammatory cytokines and steroid superfamily hormones.


Assuntos
Adenosina Difosfato Ribose/farmacologia , Antígenos CD , Cálcio/metabolismo , Mesângio Glomerular/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , ADP-Ribosil Ciclase , ADP-Ribosil Ciclase 1 , Adenosina Difosfato Ribose/análogos & derivados , Animais , Antígenos de Diferenciação/metabolismo , Cátions Bivalentes , Células Cultivadas , ADP-Ribose Cíclica , Mesângio Glomerular/efeitos dos fármacos , Interleucina-1/farmacologia , Lipopolissacarídeos/farmacologia , Masculino , Glicoproteínas de Membrana , NAD+ Nucleosidase/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Tretinoína/farmacologia , Tri-Iodotironina/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Regulação para Cima , Vasopressinas/farmacologia
10.
J Nucl Med Technol ; 29(2): 61-6; test 74-5, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11376097

RESUMO

OBJECTIVES: The patient who has been dosed with therapeutic activities of (131)I for thyroid carcinoma poses a unique set of problems for nuclear medicine technologists in their efforts to reduce personnel exposure and control contamination spread. It is the objective of this article to: (a) review practical radiation safety concerns associated with hospitalized (131)I therapy patients; (b) propose preventative measures that can be taken to minimize potential exposure and contamination problems; and (c) review pertinent federal regulations that apply to patients containing therapeutic levels of radionuclides.


Assuntos
Radioisótopos do Iodo/uso terapêutico , Proteção Radiológica , Neoplasias da Glândula Tireoide/radioterapia , Equipamentos Descartáveis , Hospitalização , Humanos , Isolamento de Pacientes , Monitoramento de Radiação , Proteção Radiológica/legislação & jurisprudência
11.
J Vasc Surg ; 33(2): 400-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11174796

RESUMO

BACKGROUND: Tissue factor (TF)-initiated thrombin generation has been implicated in the development of intimal hyperplasia after arterial injury. An increase in intimal TF expression has been shown to precede the development of intimal hyperplasia in vein grafts. This study examines the effects of local treatment with recombinant human tissue factor pathway inhibitor (rTFPI) in experimental vein grafts. METHODS: Thirty-six male New Zealand white rabbits underwent bypass grafting of the carotid artery by use of the reversed ipsilateral jugular vein and were divided into four groups. Twenty animals had ex vivo incubation with rTFPI treatment (50 microg x mL(-1); n = 10) or placebo vehicle (control; n = 10). Sixteen animals received both ex vivo incubation and in vivo gel treatment with rTFPI (50 microg. mL(-1); n = 8) or without rTFPI (gel-control; n = 8). After operation, vein grafts were harvested at 3 days for immunohistochemical and Western analyses and at 28 days for histomorphologic study. RESULTS: Western analysis demonstrated a 6.2-fold reduction in the expression of TF protein with rTFPI treatment in comparison to without rTFPI treatment. CD-18 leukocyte staining was diminished, whereas Tie-2 endothelial staining was increased in all rTFPI-treated vein grafts, compared with control and gel-control vein grafts. Intimal thickness was reduced by 21% with ex vivo rTFPI treatment compared with placebo (69 +/- 4 versus 87 +/- 5 microm; P <.05) and by 30% with the addition of rTFPI in vivo compared with gel-control (60 +/- 4 versus 86 +/- 5 microm; P <.01). CONCLUSION: Local administration of rTFPI exerts early beneficial effects and limits the development of intimal hyperplasia in vein grafts. Therefore blocking TF-mediated pathway may offer new therapeutic options to reduce vein graft failure.


Assuntos
Anticoagulantes/farmacologia , Veias Jugulares/patologia , Veias Jugulares/transplante , Lipoproteínas/farmacologia , Túnica Íntima/patologia , Animais , Western Blotting , Antígenos CD18/análise , Artérias Carótidas/cirurgia , Hiperplasia , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Coelhos , Proteínas Recombinantes/farmacologia , Tromboplastina/biossíntese , Túnica Íntima/metabolismo
12.
Biochem J ; 353(Pt 3): 531-6, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11171049

RESUMO

Nicotinic acid-adenine dinucleotide phosphate (NAADP), a molecule derived from beta-NADP, has been shown to promote intracellular calcium release in sea urchin eggs. However, there is little information regarding the role of NAADP in the regulation of intracellular calcium fluxes in mammalian cells. We found recently that several mammalian tissues have a high capacity for NAADP synthesis, as assessed by sea urchin egg bioassay. To determine the functional significance of NAADP production by mammalian tissues, we sought to determine whether NAADP is capable of inducing calcium release from microsomes prepared from cultured cells. We found that NAADP, but not beta-NADP, activates a specific microsomal calcium release system in mesangial cells isolated from rat kidney; NAADP was without effect in renal tubular epithelial cells. NAADP-induced calcium release is not affected by inhibitors of the inositol 1,4,5-trisphosphate or ryanodine channels. However, NAADP-elicited calcium release was inhibited by L-type calcium channel blockers and by alkaline phosphatase treatment of NAADP. NAADP also promotes specific microsomal calcium release in rat vascular smooth muscle cells, cardiac myocytes, fibroblasts and a human leukaemia cell line, indicating that the capacity for NAADP-induced calcium release is widespread in mammalian cells. We propose that NAADP may be an important regulator of intracellular calcium in many mammalian tissues.


Assuntos
Cálcio/metabolismo , Microssomos/efeitos dos fármacos , NADP/análogos & derivados , NADP/farmacologia , Adenosina Difosfato Ribose/análogos & derivados , Adenosina Difosfato Ribose/farmacologia , Animais , Células Cultivadas , ADP-Ribose Cíclica , Mesângio Glomerular/efeitos dos fármacos , Mesângio Glomerular/metabolismo , Mesângio Glomerular/ultraestrutura , Concentração de Íons de Hidrogênio , Inositol 1,4,5-Trifosfato/farmacologia , Microssomos/metabolismo , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Rianodina/metabolismo
13.
Clin Ther ; 22(6): 654-72, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10929915

RESUMO

OBJECTIVE: This paper presents a synopsis of the pathophysiology of gastroesophageal reflux disease (GERD) and the efficacy, safety, and cost of the agents commonly used in its treatment. BACKGROUND: Symptomatic relief of GERD can be obtained with lifestyle changes (avoidance of factors that may exacerbate symptoms, such as overeating and use of alcohol and tobacco) and use of over-the-counter medications such as antacids or histamine-2 (H2)-receptor antagonists. When these measures are unsuccessful, treatment with prescription-strength medications is required to prevent complications, such as Barrett's esophagus or esophageal adenocarcinoma. METHODS: Current guidelines for the management of GERD were identified through a MEDLINE search of the English-language literature from January 1995 through December 1999 and a search of the bibliographies of identified articles. CONCLUSION: Patients who do not respond to initial therapy should be managed with prescription-strength H2-receptor antagonists. Endoscopy should be considered for patients with atypical or refractory symptoms. Patients with a confirmed diagnosis of refractory GERD, severe esophagitis, Barrett's esophagus, or peptic stricture should be treated with and maintained on a proton-pump inhibitor.


Assuntos
Refluxo Gastroesofágico/tratamento farmacológico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Refluxo Gastroesofágico/economia , Humanos , Guias de Prática Clínica como Assunto
14.
Kidney Int ; 55(5): 1832-42, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10231445

RESUMO

BACKGROUND: For treatment of phosphate (Pi) overload in various pathophysiological states, an agent that selectively increases renal Pi excretion would be of major value. Previously, we have shown that dopamine (DA) inhibits Na(+)-Pi cotransport in renal epithelia. However, the administration of DA or its immediate precursor L-DOPA increases DA in multiple tissues. Synthetic dipeptide gamma-L-glutamyl-L-DOPA (gludopa) can serve as an inactive precursor (pro-pro-drug) of DA. This study tested the hypothesis that, because of the unique colocalization of gamma-glutamyltransferase (gamma-GT), aromatic amino acid decarboxylase, Na(+)-Pi cotransporter, and Na(+)-L-DOPA cotransporter in brush border membrane (BBM) of proximal tubular cells, gludopa may elicit phosphaturia by action of DA generated within the kidney. METHODS: Thyroparathyrectomized rats were given placebo, or gludopa, or gludopa + gamma-GT inhibitor acivicin. Urinary excretion of Pi, Ca2+, Na+, K+, DA, cAMP, and cGMP was determined, and Na(+)-Pi cotransport was measured in BBM prepared from kidneys of rats at the end of the experiment. RESULTS: The administration of gludopa resulted in: (a) an inhibition of Na(+)-Pi cotransport, but not cotransport of Na(+)-proline and Na(+)-alanine in BBM; (b) an increase (+300%) of fractional excretion (FE) of Pi and a drop (-35%) of plasma Pi, whereas the plasma levels and FEs of Ca2+, Na+, and K+ were unchanged; (c) an increase in urinary excretion of cAMP. but not cGMP; (d) a 1000-fold increase of urinary excretion of DA, without a change in excretion of norepinephrine; and (e) an incubation of gludopa with BBM in vitro, which caused a release of L-DOPA, and the in vivo administration of acivicin, which blocked actions of gludopa to inhibit Na(+)-Pi cotransport and to increase urinary excretions of Pi and DA. CONCLUSIONS: We conclude that colocalization of enzymes of biotransformation, BBM transporters, and the autocrine/paracrine DA system in cells of proximal tubules constitutes a cellular basis for the potent and specific phosphaturic action of gludopa.


Assuntos
Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/metabolismo , Di-Hidroxifenilalanina/análogos & derivados , Túbulos Renais Proximais/enzimologia , Fosfatos/urina , Simportadores , Alanina/farmacocinética , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Cálcio/sangue , Cálcio/urina , AMP Cíclico/urina , GMP Cíclico/urina , Di-Hidroxifenilalanina/farmacologia , Dopamina/urina , Túbulos Renais Proximais/química , Levodopa/sangue , Levodopa/urina , Masculino , Microvilosidades/química , Microvilosidades/enzimologia , Norepinefrina/urina , Paratireoidectomia , Fosfatos/sangue , Potássio/sangue , Potássio/urina , Prolina/farmacocinética , Ratos , Sódio/sangue , Sódio/urina , Proteínas Cotransportadoras de Sódio-Fosfato , Trítio , gama-Glutamiltransferase/metabolismo
15.
Genomics ; 57(1): 1-8, 1999 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-10191078

RESUMO

A 5000-rad whole genome radiation hybrid panel is described for the domestic cat, derived from irradiated male feline fibroblasts fused to a recipient hamster cell line. A panel of 93 cell lines has an estimated retention frequency of 0.39 (range 0.13-0.71) based upon PCR typing of 54 feline markers. To test the panel's utility, we determined the order of 16 Type I (coding gene) loci, 14 Type II (microsatellite) loci, and 1 endogenous retroviral element on feline chromosomes B4 and D3. Assessment of marker order derived from the RH panel was compared to assignments of the same loci using interspecies backcross mapping data, human homologue positions, and human-cat chromosome painting homologies. Assessment of concordant and discordant marker order for these loci provides improved resolution into the evolution of subchromosomal genome organizations and the methods to track them in these species.


Assuntos
Gatos/genética , Mapeamento Cromossômico/métodos , Repetições de Microssatélites , Animais , Coloração Cromossômica , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 22 , Cricetinae , Primers do DNA , Fibroblastos/metabolismo , Humanos , Células Híbridas , Masculino , Modelos Genéticos , Dados de Sequência Molecular , Mapeamento Físico do Cromossomo
16.
Oncogene ; 18(11): 1983-91, 1999 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-10208420

RESUMO

D-type cyclins are important cell cycle regulators that promote cellular proliferation in response to growth factors by inactivation of the retinoblastoma protein (Rb). Cyclin D1 has been shown to be overexpressed in several cancer types and to act as an oncogene in breast cancers. As D-type cyclins are rate limiting for progression into S phase, the level at which they accumulate must be carefully regulated. Several mechanisms leading to overexpression of cyclin D1 have been reported including amplification, translocation and stabilization of the mRNA. Here, we present data showing elevated cyclin D1 protein in breast cancer samples in the absence of elevated mRNA level. Further, we found that in these cases, cyclin D3 protein also accumulates and that the coordinate increase in cyclin D1 and D3 occurs in 15% (7/47) of breast cancers. In addition we show that blocking the activity of the 26S proteosome results in the accumulation of cyclin D1 and D3, that both D-type cyclins are ubiquitinated and associate with Cul-1, a component of the SCF ubiquitin ligase complex. Finally, we show that the coordinated elevation of cyclin D1 and D3 is also observed in the breast cell line MCF-7 and demonstrate that the degradation of cyclin D1 and D3 is deficient in this cell line. These results indicate that cyclin D1 and cyclin D3 share a common mechanism of degradation and we propose that the coordinate increase of D-type cyclins observed in primary breast cancers reflects a defect in their proteolysis.


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Culina , Ciclina D1/metabolismo , Ciclinas/metabolismo , Proteínas de Ciclo Celular/genética , Ciclina D1/genética , Ciclina D3 , Ciclinas/genética , Feminino , Humanos , RNA Mensageiro , Ubiquitinas
17.
J Biol Chem ; 273(51): 34502-10, 1998 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-9852119

RESUMO

Indolethylamine N-methyltransferase (INMT) catalyzes the N-methylation of tryptamine and structurally related compounds. This reaction has been studied because of its possible role in the in vivo synthesis of psychoactive compounds or neurotoxins and has been characterized biochemically in preparations of rabbit lung. Therefore, we set out to purify rabbit lung INMT, to clone and express its cDNA, and to clone and structurally characterize its gene as steps toward understanding the function and regulation of this enzyme. Rabbit lung INMT was purified and partial amino acid sequence was obtained. A polymerase chain reaction-based approach was then used to clone a rabbit lung INMT cDNA with a 792-base pair open reading frame that encoded a 263-amino acid protein with a predicted molecular mass of 29 kDa. When the cDNA was expressed in COS-1 cells, the encoded protein catalyzed the methylation of tryptamine and structurally related compounds, and was inhibited by two products of the reaction, S-adenosyl-L-homocysteine (AdoHcy) and N,N-dimethyltryptamine, as well as antimigraine drugs that are structurally related to N,N-dimethyltryptamine. Northern blot analysis demonstrated the presence of 2.0-kilobase mRNA species in rabbit lung, liver and, at lower levels, in brain. The cDNA was then used to clone the rabbit INMT gene. That gene had three exons and was structurally similar to the genes for nicotinamide N-methyltransferase and phenylethanolamine N-methyltransferase in several species. Cloning and expression of a rabbit lung INMT cDNA and cloning of the rabbit INMT gene represent important steps toward determination of the function and regulation of this mammalian methyltransferase enzyme.


Assuntos
Pulmão/enzimologia , Metiltransferases/genética , Metiltransferases/metabolismo , Coelhos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Cromatografia DEAE-Celulose , Cromatografia em Gel , Clonagem Molecular , DNA Complementar , Inibidores Enzimáticos/farmacologia , Evolução Molecular , Éxons , Humanos , Íntrons , Cinética , Metiltransferases/isolamento & purificação , Camundongos , Dados de Sequência Molecular , Família Multigênica , Filogenia , Ratos , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
18.
Cancer Res ; 58(22): 5168-75, 1998 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9823328

RESUMO

c-myb is expressed in human and murine colonic mucosa and elevated expression occurs in premalignant adenomatous polyps and carcinomas. c-Myb is required for colon cell proliferation, and there is evidence of c-myb down-regulation during differentiation. Recently, c-myb has been implicated in hematopoietic cell survival via regulation of bcl-2 gene expression. However, c-myb expression during terminal differentiation and apoptosis in the colonic crypt has not been examined. The experiments in this study examine the spatial and temporal expression of c-Myb protein in vivo using human colonic crypt sections and in vitro in human colon tumor cell lines undergoing butyrate-induced differentiation and apoptosis. Electron microscopy, together with molecular and biochemical analysis, was used to define the differentiation status of the cells. Results demonstrate a decrease in c-Myb expression during the commitment of cells to differentiation and apoptosis. Decreased levels of c-Myb are accompanied by a decrease in Bcl-2. These data suggest that the transcription factor c-Myb has a role in regulating the balance between proliferation, differentiation, and apoptosis in the colonic crypt. Furthermore, elevated c-Myb levels in colon tumor cells may lead to persistent bcl-2 expression, thus protecting tumor cells from programmed cell death.


Assuntos
Apoptose/genética , Diferenciação Celular/genética , Colo/citologia , Colo/metabolismo , Neoplasias do Colo/metabolismo , Oncogenes , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fosfatase Alcalina/metabolismo , Butiratos/farmacologia , Colo/efeitos dos fármacos , Colo/ultraestrutura , Neoplasias do Colo/patologia , Fragmentação do DNA , Regulação para Baixo , Indução Enzimática , Amplificação de Genes , Genes bcl-2 , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Células Tumorais Cultivadas/efeitos dos fármacos
19.
Mol Cell Biol ; 18(9): 5609-19, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9710644

RESUMO

Expression of the fos family of transcription factors is stimulated by growth factors that induce quiescent cells to reenter the cell cycle, but the cellular targets of the Fos family that regulate cell cycle reentry have not been identified. To address this issue, mice that lack two members of the fos family, c-fos and fosB, were derived. The fosB-/- c-fos-/- mice are similar in phenotype to c-fos-/- mice but are 30% smaller. This decrease in size is consistent with an abnormality in cell proliferation. Fibroblasts derived from fosB-/- c-fos-/- mice were found to have a defect in proliferation that results at least in part from a failure to induce cyclin D1 following serum-stimulated cell cycle reentry. Although definitive evidence that c-Fos and FosB directly induce cyclin D1 transcription will require further analysis, these findings raise the possibility that c-Fos and FosB are either direct or indirect transcriptional regulators of the cyclin D1 gene and may function as a critical link between serum stimulation and cell cycle progression.


Assuntos
Ciclo Celular/fisiologia , Ciclina D1/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Animais , Células Cultivadas , Cruzamentos Genéticos , Embrião de Mamíferos , Feminino , Fibroblastos , Genes fos , Heterozigoto , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Gravidez , Proteínas Proto-Oncogênicas c-fos/deficiência , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Recombinantes/metabolismo , Transfecção
20.
JAMA ; 280(1): 78-86, 1998 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9660368

RESUMO

OBJECTIVE: To provide recommendations for antiretroviral therapy based on information available in mid-1998. PARTICIPANTS: An international panel of physicians with expertise in antiretroviral research and care of patients with human immunodeficiency virus (HIV) infection, first convened by the International AIDS Society-USA in December 1995. EVIDENCE: The panel reviewed available clinical and basic science study results (including phase 3 controlled trials; clinical, virologic, and immunologic end point data; data presented at research conferences; and studies of HIV pathophysiology); opinions of panel members were also considered. Recommendations were limited to drugs available in mid-1998. CONSENSUS PROCESS: Panel members monitor new clinical research reports and interim results. The full panel meets regularly to discuss how the new information may change treatment recommendations. Updated recommendations are developed through consensus of the entire panel at each stage of development. CONCLUSIONS: Accumulating data from clinical and pathogenesis studies continue to support early institution of potent antiretroviral therapy in patients with HIV infection. A variety of combination regimens show potency, expanding choices for initial regimens for individual patients. Plasma HIV RNA assays with increased sensitivity are important in monitoring therapeutic response; however, more data are needed to determine precisely the HIV RNA levels that define treatment failure. Long-term adverse drug effects are beginning to emerge, requiring ongoing attention. Some issues regarding optimal long-term approaches to antiretroviral management are unresolved. The increased complexity in HIV management requires ongoing monitoring of new data for optimal treatment of HIV infection.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/efeitos adversos , Esquema de Medicação , Quimioterapia Combinada , Feminino , HIV/efeitos dos fármacos , HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Inibidores da Protease de HIV/uso terapêutico , Humanos , Masculino , Exposição Ocupacional , Guias de Prática Clínica como Assunto , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Inibidores da Transcriptase Reversa/uso terapêutico , Falha de Tratamento , Carga Viral , Replicação Viral/efeitos dos fármacos
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