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1.
Breast Cancer Res Treat ; 161(2): 363-373, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27866278

RESUMO

PURPOSE: We examined acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) events among 9679 women treated for breast cancer on four adjuvant Alliance for Clinical Trials in Oncology trials with >90 months of follow-up in order to better characterize the risk for AML/MDS in older patients receiving anthracyclines. METHODS: We used multivariable Cox regression to examine factors associated with AML/MDS, adjusting for age (≥65 vs. <65 years; separately for ≥70 vs. <70 years), race/ethnicity, insurance, performance status, and anthracycline receipt. We also examined the effect of cyclophosphamide, the interaction of anthracycline and age, and outcomes for those developing AML/MDS. RESULTS: On Cancer and Leukemia Group B (CALGB) 40101, 49907, 9344, and 9741, 7290 received anthracyclines; 15% were in the age ≥65 and 7% were ≥70. Overall, 47 patients developed AML/MDS (30 AML [0.3%], 17 MDS [0.2%]); 83% of events occurred within 5 years of study registration. Among those age ≥65 and ≥70, 0.8 and 1.0% developed AML/MDS (vs. 0.4% for age <65), respectively. In adjusted analyses, older age and anthracycline receipt were significantly associated with AML/MDS (adjusted hazard ratio [HR] for age ≥65 [vs. <65] = 3.13, 95% confidence interval [CI] 1.18-8.33; HR for anthracycline receipt [vs. no anthracycline] = 5.16, 95% CI 1.47-18.19). There was no interaction between age and anthracycline use. Deaths occurred in 70% of those developing AML/MDS. CONCLUSIONS: We observed an increased risk for AML/MDS for older patients and those receiving anthracyclines, though these events were rare. Our results help inform discussions surrounding anticipated toxicities of adjuvant chemotherapy in older patients.


Assuntos
Neoplasias da Mama/complicações , Neoplasias da Mama/epidemiologia , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/etiologia , Síndromes Mielodisplásicas/epidemiologia , Síndromes Mielodisplásicas/etiologia , Segunda Neoplasia Primária , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antraciclinas/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/efeitos adversos , Estudos de Coortes , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Risco , Fatores de Tempo
2.
Br J Cancer ; 111(8): 1532-41, 2014 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-25101563

RESUMO

BACKGROUND: In this study, we evaluated the ability of gene expression profiles to predict chemotherapy response and survival in triple-negative breast cancer (TNBC). METHODS: Gene expression and clinical-pathological data were evaluated in five independent cohorts, including three randomised clinical trials for a total of 1055 patients with TNBC, basal-like disease (BLBC) or both. Previously defined intrinsic molecular subtype and a proliferation signature were determined and tested. Each signature was tested using multivariable logistic regression models (for pCR (pathological complete response)) and Cox models (for survival). Within TNBC, interactions between each signature and the basal-like subtype (vs other subtypes) for predicting either pCR or survival were investigated. RESULTS: Within TNBC, all intrinsic subtypes were identified but BLBC predominated (55-81%). Significant associations between genomic signatures and response and survival after chemotherapy were only identified within BLBC and not within TNBC as a whole. In particular, high expression of a previously identified proliferation signature, or low expression of the luminal A signature, was found independently associated with pCR and improved survival following chemotherapy across different cohorts. Significant interaction tests were only obtained between each signature and the BLBC subtype for prediction of chemotherapy response or survival. CONCLUSIONS: The proliferation signature predicts response and improved survival after chemotherapy, but only within BLBC. This highlights the clinical implications of TNBC heterogeneity, and suggests that future clinical trials focused on this phenotypic subtype should consider stratifying patients as having BLBC or not.


Assuntos
Antineoplásicos/uso terapêutico , Análise de Sobrevida , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento , Neoplasias de Mama Triplo Negativas/fisiopatologia
3.
mBio ; : e0070724, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832780

RESUMO

Bacterial communities are highly complex, with interaction networks dictating ecosystem function. Bacterial interactions are constrained by the spatial organization of these microbial communities, yet studying the spatial organization of microbial communities at the single-cell level has been technically challenging. Here, we use the recently developed high-phylogenetic-resolution microbiota mapping by fluorescence in situ hybridization technology to image the gut microbiota at the species and single-cell level. We simultaneously image 63 different bacterial species to spatially characterize the perturbation and recovery of the gut microbiota to ampicillin and vancomycin in the cecum and distal colon of mice. To decipher the biology in this complex imaging data, we developed an analytical framework to characterize the spatial changes of the gut microbiota to a perturbation. The three-tiered analytical approach includes image-level diversity, pairwise colocalization analysis, and hypothesis-driven neighborhood analysis. Through this workflow, we identify biogeographic and antibiotic-based differences in the spatial organization of the gut microbiota. We demonstrate that the cecal microbiota has increased micrometer-scale diversity than the colon at baseline and recovers better from perturbation. Also, we identify potential foundation and keystone species that have high baseline neighborhood richness and that are associated with recovery from antibiotics. Through this workflow, we add a spatial layer to the characterization of bacterial communities and progress toward a better understanding of bacterial interactions leading to improved microbiome modulation strategies. IMPORTANCE: Antibiotics have broad off-target effects on the gut microbiome. When the microbial community is unable to recover from antibiotics, it can lead to increased susceptibility to gastrointestinal infections and increased risk of immunological and metabolic diseases. In this study, we work to better understand how the gut microbiota recovers from antibiotics by employing a recent technology to image the entire bacterial community at once. Through this approach, we characterize the spatial changes in the gut microbiota after treatment with model antibiotics in both the cecum and colon of mice. We find antibiotic- and biogeographic-dependent spatial changes between bacterial species and that many of these spatial colocalizations do not recover to baseline levels even 35 days after antibiotic administration.

4.
Nat Med ; 1(12): 1291-6, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7489411

RESUMO

Several missense mutations causing early-onset Alzheimer's disease (AD) have been described in the gene coding for the beta-amyloid precursor protein (beta APP). A double mutation found in a Swedish family is located before the amyloid beta-peptide (A beta) region of beta APP and results in the increased production and secretion of A beta. Here we show that the increased production of A beta results from a cellular mechanism, which differs substantially from that responsible for the production of A beta from wild-type beta APP. In the latter case, A beta generation requires reinternalization and recycling of beta APP. In the case of the Swedish mutation the N-terminal beta-secretase cleavage of A beta occurs in Golgi-derived vesicles, most likely within secretory vesicles. Therefore, this cleavage occurs in the same compartment as the alpha-secretase cleavage, which normally prevents A beta production, explaining the increased A beta generation by a competition between alpha- and beta-secretase.


Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Endopeptidases/metabolismo , Idade de Início , Idoso , Doença de Alzheimer/metabolismo , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases , Encéfalo/metabolismo , Complexo de Golgi/metabolismo , Humanos , Dados de Sequência Molecular , Mutação , Suécia
5.
Nat Med ; 2(8): 864-70, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8705854

RESUMO

To determine whether the presenilin 1 (PS1), presenilin 2 (PS2) and amyloid beta-protein precursor (APP) mutations linked to familial Alzheimer's disease (FAD) increase the extracellular concentration of amyloid beta-protein (A beta) ending at A beta 42(43) in vivo, we performed a blinded comparison of plasma A beta levels in carriers of these mutations and controls. A beta 1-42(43) was elevated in plasma from subjects with FAD-linked PS1 (P < 0.0001), PS2N1411 (P = 0.009), APPK670N,M671L (P < 0.0001), and APPV7171 (one subject) mutations. A beta ending at A beta 42(43) was also significantly elevated in fibroblast media from subjects with PS1 (P < 0.0001) or PS2 (P = 0.03) mutations. These findings indicate that the FAD-linked mutations may all cause Alzhelmer's disease by increasing the extracellular concentration of A beta 42(43), thereby fostering cerebral deposition of this highly amyloidogenic peptide.


Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Proteínas de Membrana/genética , Mutação , Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/sangue , Células Cultivadas , Meios de Cultivo Condicionados , Feminino , Fibroblastos , Humanos , Masculino , Fragmentos de Peptídeos/sangue , Presenilina-1 , Presenilina-2
6.
Nat Med ; 3(1): 67-72, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8986743

RESUMO

The mechanism by which mutations in the presenilin (PS) genes cause the most aggressive form of early-onset Alzheimer's disease (AD) is unknown, but fibroblasts from mutation carriers secrete increased levels of the amyloidogenic A beta 42 peptide, the main component of AD plaques. We established transfected cell and transgenic mouse models that coexpress human PS and amyloid beta-protein precursor (APP) genes and analyzed quantitatively the effects of PS expression on APP processing. In both models, expression of wild-type PS genes did not alter APP levels, alpha- and beta-secretase activity and A beta production. In the transfected cells, PS1 and PS2 mutations caused a highly significant increase in A beta 42 secretion in all mutant clones. Likewise, mutant but not wildtype PS1 transgenic mice showed significant overproduction of A beta 42 in the brain, and this effect was detectable as early as 2-4 months of age. Different PS mutations had differential effects on A beta generation. The extent of A beta 42 increase did not correlate with presenilin expression levels. Our data demonstrate that the presenilin mutations cause a dominant gain of function and may induce AD by enhancing A beta 42 production, thus promoting cerebral beta-amyloidosis.


Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Proteínas de Membrana/genética , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/imunologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Mutação , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Presenilina-1 , Presenilina-2 , Transfecção
7.
J Environ Manage ; 92(9): 2119-29, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21561705

RESUMO

The direct influence of ship traffic on atmospheric levels of coarse and fine particulate matter (PM(2.5), PM(10)) and fifteen polycyclic aromatic hydrocarbons (PAHs) has been estimated in the urban area of Venice. Data analysis has been performed on results collected at three sites over the summer, when ship traffic is at a maximum. Results indicate that monitoring of the PM daily concentrations is not sufficiently detailed for the evaluation of this contribution, even though it could be useful for specific markers such as PAHs. Therefore a new methodology, based on high temporal resolution measurements coupled with wind direction information and the database of ship passages of the Harbour Authority of Venice has been developed. The sampling sites were monitored with optical detectors (DustTrack(®) and Mie pDR-1200) operating at a high temporal resolution (20s and 1s respectively) for PM(2.5) and PM(10). PAH in the particulate and gas phases were recovered from quartz fibre filters and polyurethane foam plugs using pressurised solvent extraction, the extracts were then analysed by gas chromatography- high-resolution mass spectrometry. Our results shows that the direct contribution of ships traffic to PAHs in the gas phase is 10% while the contribution to PM(2.5) and to PM(10) is from 1% up to 8%.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Navios , Emissões de Veículos/análise , Itália , Estações do Ano , Vento
8.
Science ; 201(4354): 469-70, 1978 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-663670

RESUMO

Ultrafine glass micropipettes can be easily beveled in a jet stream of grinding compound suspended in saline. The beveling is gradual and continuous, highly reliable, and can be accomplished with common laboratory apparatus. The beveled electrodes are comparable in performance to those prepared with expensive commercial bevelers.


Assuntos
Microeletrodos , Microinjeções/instrumentação , Vidro , Peroxidase do Rábano Silvestre/administração & dosagem
9.
Science ; 286(5440): 735-41, 1999 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-10531052

RESUMO

Cerebral deposition of amyloid beta peptide (Abeta) is an early and critical feature of Alzheimer's disease. Abeta generation depends on proteolytic cleavage of the amyloid precursor protein (APP) by two unknown proteases: beta-secretase and gamma-secretase. These proteases are prime therapeutic targets. A transmembrane aspartic protease with all the known characteristics of beta-secretase was cloned and characterized. Overexpression of this protease, termed BACE (for beta-site APP-cleaving enzyme) increased the amount of beta-secretase cleavage products, and these were cleaved exactly and only at known beta-secretase positions. Antisense inhibition of endogenous BACE messenger RNA decreased the amount of beta-secretase cleavage products, and purified BACE protein cleaved APP-derived substrates with the same sequence specificity as beta-secretase. Finally, the expression pattern and subcellular localization of BACE were consistent with that expected for beta-secretase. Future development of BACE inhibitors may prove beneficial for the treatment of Alzheimer's disease.


Assuntos
Doença de Alzheimer/enzimologia , Peptídeos beta-Amiloides/biossíntese , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/isolamento & purificação , Ácido Aspártico Endopeptidases/metabolismo , Doença de Alzheimer/tratamento farmacológico , Motivos de Aminoácidos , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide , Animais , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/genética , Sítios de Ligação , Encéfalo/enzimologia , Encéfalo/metabolismo , Linhagem Celular , Clonagem Molecular , Endopeptidases , Endossomos/enzimologia , Expressão Gênica , Biblioteca Gênica , Complexo de Golgi/enzimologia , Humanos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Oligonucleotídeos Antissenso/farmacologia , Peptídeos/metabolismo , Inibidores de Proteases/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
10.
Neuron ; 14(3): 661-70, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7695913

RESUMO

Cerebral deposition of amyloid beta protein (A beta) is an early and critical feature of Alzheimer's disease. Here we analyze the substrate requirements of proteases ("beta-secretases") that cleave the beta-amyloid precursor protein (beta APP) at the N-terminus of A beta (Asp-597 of beta APP695) in intact human cells. The cleavage requires a membrane-bound substrate but tolerates shifts in the distance of the hydrolyzed bond from the membrane. The major protease has a minimum recognition region of Val-594 to Ala-598; most substitutions in this sequence strongly decrease or eliminate A beta production. Only the Swedish familial Alzheimer's disease mutation (K595N/M596L) strongly increases A beta production. Moreover, in this mutant but not in the wild type, the entire cytoplasmic tail with its reinternalization signals can be deleted without affecting A beta N-terminal cleavage, consistent with the concept that cleavage of this mutant occurs in a different cellular compartment than that of wild-type molecules. Our results have important implications for current intensive approaches to develop assays for and identify enzymes with beta-secretase activity.


Assuntos
Peptídeos beta-Amiloides/biossíntese , Precursor de Proteína beta-Amiloide/metabolismo , Endopeptidases/metabolismo , Processamento de Proteína Pós-Traducional , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide , Peptídeos beta-Amiloides/química , Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/genética , Ácido Aspártico Endopeptidases , Sequência de Bases , Encéfalo/metabolismo , Linhagem Celular , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Neuroblastoma , Oligodesoxirribonucleotídeos , Mutação Puntual , Especificidade por Substrato , Transfecção , Células Tumorais Cultivadas
11.
Neuron ; 17(1): 171-9, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8755488

RESUMO

Cerebral deposition of amyloid beta protein (A beta) is an early and critical feature of Alzheimer's disease. A beta production requires the proteolytic release of A beta from the beta-amyloid precursor protein (beta APP). Thus, inhibition of A beta release is a prime therapeutic goal. Here, we show that the broad spectrum, irreversible serine protease inhibitor, AEBSF, inhibits the constitutive production of A beta in five different human cell lines, both neural and nonneural. AEBSF also stabilizes full-length beta APP and enhances alpha-secretion, as shown by an increase in the proteolytic derivative, alpha-APPS. Further, we demonstrate that the inhibitory effect of AEBSF is specific for A beta proteins starting at Aspartate 1, suggesting that AEBSF directly inhibits beta-secretase, the Methionine-Aspartate (Met-Asp)-cleaving enzyme. These results indicate that specific inhibition of this A beta-generating protease is possible in living human neural cells and provide information about the characteristics of this as yet unidentified enzyme.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Neurônios/metabolismo , Inibidores de Serina Proteinase/farmacologia , Sulfonas/farmacologia , Sequência de Aminoácidos , Peptídeos beta-Amiloides/biossíntese , Peptídeos beta-Amiloides/genética , Precursor de Proteína beta-Amiloide/metabolismo , Linhagem Celular , Humanos , Fragmentos de Peptídeos/metabolismo
12.
Eur Phys J C Part Fields ; 78(3): 256, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31258409

RESUMO

We use MasterCode to perform a frequentist analysis of the constraints on a phenomenological MSSM model with 11 parameters, the pMSSM11, including constraints from ∼ 36 /fb of LHC data at 13 TeV and PICO, XENON1T and PandaX-II searches for dark matter scattering, as well as previous accelerator and astrophysical measurements, presenting fits both with and without the ( g - 2 ) µ constraint. The pMSSM11 is specified by the following parameters: 3 gaugino masses M 1 , 2 , 3 , a common mass for the first-and second-generation squarks m q ~ and a distinct third-generation squark mass m q ~ 3 , a common mass for the first-and second-generation sleptons m ℓ ~ and a distinct third-generation slepton mass m τ ~ , a common trilinear mixing parameter A, the Higgs mixing parameter µ , the pseudoscalar Higgs mass M A and tan ß . In the fit including ( g - 2 ) µ , a Bino-like χ ~ 1 0 is preferred, whereas a Higgsino-like χ ~ 1 0 is mildly favoured when the ( g - 2 ) µ constraint is dropped. We identify the mechanisms that operate in different regions of the pMSSM11 parameter space to bring the relic density of the lightest neutralino, χ ~ 1 0 , into the range indicated by cosmological data. In the fit including ( g - 2 ) µ , coannihilations with χ ~ 2 0 and the Wino-like χ ~ 1 ± or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the χ ~ 2 0 and the Higgsino-like χ ~ 1 ± or with first- and second-generation squarks may be important when the ( g - 2 ) µ constraint is dropped. In the two cases, we present χ 2 functions in two-dimensional mass planes as well as their one-dimensional profile projections and best-fit spectra. Prospects remain for discovering strongly-interacting sparticles at the LHC, in both the scenarios with and without the ( g - 2 ) µ constraint, as well as for discovering electroweakly-interacting sparticles at a future linear e + e - collider such as the ILC or CLIC.

13.
Eur Phys J C Part Fields ; 77(2): 104, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28260982

RESUMO

We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has seven parameters: a universal gaugino mass [Formula: see text], distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), [Formula: see text] and [Formula: see text], and for the [Formula: see text] and [Formula: see text] Higgs representations [Formula: see text] and [Formula: see text], a universal trilinear soft SUSY-breaking parameter [Formula: see text], and the ratio of Higgs vevs [Formula: see text]. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + [Formula: see text] events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel [Formula: see text] coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of [Formula: see text] coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC.

14.
Eur Phys J C Part Fields ; 77(4): 268, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28515671

RESUMO

We perform a likelihood analysis of the minimal anomaly-mediated supersymmetry-breaking (mAMSB) model using constraints from cosmology and accelerator experiments. We find that either a wino-like or a Higgsino-like neutralino LSP, [Formula: see text], may provide the cold dark matter (DM), both with similar likelihoods. The upper limit on the DM density from Planck and other experiments enforces [Formula: see text] after the inclusion of Sommerfeld enhancement in its annihilations. If most of the cold DM density is provided by the [Formula: see text], the measured value of the Higgs mass favours a limited range of [Formula: see text] (and also for [Formula: see text] if [Formula: see text]) but the scalar mass [Formula: see text] is poorly constrained. In the wino-LSP case, [Formula: see text] is constrained to about [Formula: see text] and [Formula: see text] to [Formula: see text], whereas in the Higgsino-LSP case [Formula: see text] has just a lower limit [Formula: see text] ([Formula: see text]) and [Formula: see text] is constrained to [Formula: see text] in the [Formula: see text] ([Formula: see text]) scenario. In neither case can the anomalous magnetic moment of the muon, [Formula: see text], be improved significantly relative to its Standard Model (SM) value, nor do flavour measurements constrain the model significantly, and there are poor prospects for discovering supersymmetric particles at the LHC, though there are some prospects for direct DM detection. On the other hand, if the [Formula: see text] contributes only a fraction of the cold DM density, future LHC [Formula: see text]-based searches for gluinos, squarks and heavier chargino and neutralino states as well as disappearing track searches in the wino-like LSP region will be relevant, and interference effects enable [Formula: see text] to agree with the data better than in the SM in the case of wino-like DM with [Formula: see text].

15.
J Natl Cancer Inst ; 84(5): 337-40, 1992 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-1738185

RESUMO

BACKGROUND: The level of the DNA repair protein O6-methylguanine-DNA methyltransferase is an important determinant of the response of tumor cells in culture to alkylating nitrosoureas. In these cells, the abundance of messenger RNA (mRNA) is directly correlated with repair activity. PURPOSE: Our purpose was to compare transferase mRNA levels with the repair activity in primary human tumors. METHODS: Human transferase mRNA was measured in tissue samples from brain tumors, normal lung, lung tumors, ovarian tumors, and normal human liver by use of an RNA protection assay with an antisense probe prepared from the cloned gene. RESULTS: Normal and tumor tissue samples from the same patient had similar transferase activity levels, but transferase expression varied widely among tissue samples from different patients. Brain and lung samples, on average, had transferase mRNA levels closer to those in liver samples than their transferase activity levels. In two cases, tissue samples which were transferase deficient by the activity assays were found to lack transferase mRNA. CONCLUSIONS: Deficiencies in transferase activity are due to reduced or absent mRNA transcription or processing. In brain and lung, there may be post-transcriptional control of mRNA expression. The wide interindividual variation in transferase expression is also seen at the transcription level. IMPLICATIONS: These are among the first measures of transferase mRNA expression in primary human tissue. More samples should be examined to extend these observations.


Assuntos
Metiltransferases/genética , Neoplasias/enzimologia , Neoplasias Encefálicas/enzimologia , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Fígado/enzimologia , Neoplasias Hepáticas/enzimologia , Pulmão/enzimologia , Neoplasias Pulmonares/enzimologia , O(6)-Metilguanina-DNA Metiltransferase , Especificidade de Órgãos , Neoplasias Ovarianas/enzimologia , RNA Mensageiro/análise , RNA Neoplásico/análise
16.
Cancer Res ; 46(3): 1214-8, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3002612

RESUMO

Bombesin/gastrin releasing peptide-like immunoreactivity (BLI) is found in the majority of small cell carcinoma of the lung (SCCL) cell lines examined. Because BLI is present in high concentration in SCCL we studied the mechanism of BLI secretion from several SCCL cell lines and in patients with SCCL. In cell line NCI-H345 the structurally related polypeptide hormones secretin, vasoactive intestinal peptide, and peptide histidine isoleucine as well as theophylline, a phosphodiesterase inhibitor, N6,O2'-dibutyryl cyclic adenosine 3':5'-monophosphate, a cyclic nucleotide analogue, increased BLI release by 16-120% and cyclic adenosine 3':5'-monophosphate by 36-350%. Similar results were obtained in SCCL cell line NCI-H209. i.v. injection of secretin (2 units/kg) significantly increased plasma BLI in 2 patients with extrapulmonary SCCL. These data suggest that SCCL cells possess receptors for secretin/vasoactive intestinal peptide and that receptor occupation stimulates in vitro and in vivo BLI secretion.


Assuntos
Bombesina/metabolismo , Carcinoma de Células Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Peptídeos/metabolismo , Secretina/farmacologia , Taxa Secretória/efeitos dos fármacos , Peptídeo Intestinal Vasoativo/farmacologia , Alprostadil/farmacologia , Bucladesina/farmacologia , AMP Cíclico/metabolismo , Peptídeo Liberador de Gastrina , Humanos , Peptídeo PHI , Peptídeos/farmacologia , Teofilina/farmacologia , Fatores de Tempo
17.
Cancer Res ; 51(16): 4131-4, 1991 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-1868433

RESUMO

The resistance of human tumor strains in culture to cell killing by alkylating nitrosoureas is correlated with their levels of the DNA repair activity O6-methylguanine-DNA methyltransferase. Strains with the Mer- phenotype have no activity and are extremely sensitive. However, the relationship between the sensitivity of human tumors in vivo and transferase levels is not known, and even the existence of Mer- human tumors in vivo has been questioned. In this study 73 human tumor and normal tissue samples from brain, lung, and ovary were assayed for transferase levels and methylpurine glycosylase activity. For each organ, transferase levels varied over 100-fold, and Mer- tumors were detected in each group. There was no correlation between transferase and glycosylase levels, indicating that the absence of transferase in some tumor samples was not an artifact due to necrosis or inactivation of enzymes in the extract.


Assuntos
Proteínas de Bactérias/metabolismo , Neoplasias Encefálicas/enzimologia , Encéfalo/enzimologia , Proteínas de Escherichia coli , Neoplasias Pulmonares/enzimologia , Pulmão/enzimologia , Neoplasias Ovarianas/enzimologia , Ovário/enzimologia , Feminino , Humanos , Cinética , O(6)-Metilguanina-DNA Metiltransferase , Valores de Referência , Fatores de Transcrição
18.
Cancer Res ; 52(15): 4227-31, 1992 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-1638536

RESUMO

UV exposure has been linked to skin cancer in humans by epidemiology and the rare genetic disease xeroderma pigmentosum. However, UV produces multiple photoproducts in DNA, and their relative contribution is uncertain. An enzyme which specifically repairs cyclobutane pyrimidine dimers in DNA, T4 endonuclease V, was encapsulated in liposomes for topical delivery into mouse and human skin. In both species, liposomes applied after UV exposure localized in the epidermis and stimulated the removal of cyclobutane pyrimidine dimers. UV-irradiated mice treated with these liposomes had a dose-dependent decrease in the incidence of squamous cell carcinoma compared to controls. The results demonstrate that unrepaired cyclobutane pyrimidine dimers in DNA are a direct cause of cancer in mammalian skin.


Assuntos
Reparo do DNA , Endodesoxirribonucleases/administração & dosagem , Endodesoxirribonucleases/uso terapêutico , Neoplasias Induzidas por Radiação/prevenção & controle , Neoplasias Cutâneas/prevenção & controle , Pele/efeitos da radiação , Raios Ultravioleta , Proteínas Virais , Animais , Dano ao DNA , Desoxirribonuclease (Dímero de Pirimidina) , Portadores de Fármacos , Endodesoxirribonucleases/farmacocinética , Feminino , Humanos , Lipossomos , Camundongos , Camundongos Pelados , Neoplasias Induzidas por Radiação/etiologia , Técnicas de Cultura de Órgãos , Dímeros de Pirimidina/análise , Pele/patologia , Neoplasias Cutâneas/etiologia , Fagos T/enzimologia , Distribuição Tecidual
19.
Cancer Res ; 56(4): 783-8, 1996 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8631014

RESUMO

We tested the hypothesis that the level of the DNA repair protein O6-alkylguanine-DNA alkyltransferase in brain tumors was correlated with resistance to carmustine (BCNU) chemotherapy. Alkyltransferase levels in individual cells in sections from 167 primary brain tumors treated with BCNU were quantitated with an immunofluorescence assay using monoclonal antibodies against human alkyltransferase. Patients with high levels of alkyltransferase had shorter time to treatment failure (P = 0.05) and death (P = 0.004) and a death rate 1.7 times greater than patients with low alkyltransferase levels. Furthermore, the size of the subpopulation of cells with high levels of alkyltransferase was correlated directly with drug resistance. For all tumors the variables most closely correlated with survival, in order of importance, were age, tumor grade, and alkyltransferase levels. For glioblastoma multiforme, survival was more strongly correlated with alkyltransferase levels than with age. These results should encourage prospective studies to evaluate alkyltransferase levels as a method, for identifying brain tumor patients with the best likelihood of response to BCNU chemotherapy.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Carmustina/uso terapêutico , Reparo do DNA , Metiltransferases/análise , Anticorpos Monoclonais , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/radioterapia , Terapia Combinada , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , O(6)-Metilguanina-DNA Metiltransferase , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo
20.
J Clin Oncol ; 13(6): 1443-52, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7751891

RESUMO

PURPOSE: We sought to compare three doxorubicin-based therapies for metastatic breast cancer for response frequency, time to treatment failure (TTF), and survival. MATERIALS AND METHODS: Women with metastatic breast cancer who had measurable disease, required laboratory tests, had received no prior chemotherapy for metastases, had a Cancer and Leukemia Group B (CALGB) performance status < or = 2, and provided informed consent were eligible. Treatment included the following: arm I--cyclophosphamide, doxorubicin, and fluorouracil (CAF); arm II--vinblastine, doxorubicin, thiotepa, and halotestin (VATH); and arm III--VATH alternating with cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) on cycles 3, 5, 7, 9, etc. Doses were modified for toxicities. Standard CALGB response and toxicity criteria were used. RESULTS: Between August 1982 and February 1987, 497 women were entered and 491 were treated on study. Pretreatment characteristics were well balanced and the median follow-up duration was 79 months. There were no significant differences in response (complete [CR] plus partial [PR]) at 50% on arm I, 57% on arm II, and 51% on arm III. The median TTFs were 8, 8, and 9 months, respectively, in favor of arm III when compared with arm I (P = .028). The median survival times for treatment arms I, II, and III were 15, 17, and 17 months, respectively. After multivariate regression analyses, only estrogen receptors (ER), performance status, and number of metastatic sites influenced TTF and survival. Leukopenia was the most common grade 3 or 4 toxicity, occurring in 90%, 80%, and 92% of patients per arm, respectively. Lethal toxicities were seen in four, five, and six women, respectively. Overall, there were more grade > or = 3 toxicities on arm II than I, and most occurred on arm III (P = .02). CONCLUSION: The VATH regimen appears similarly effective to the CAF regimen as initial therapy. Alternating CMFVP with VATH did not improve response rate or survival. After accounting for other variables, treatment arm was not related to outcome. New therapeutic regimens are still needed.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/mortalidade , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Fluoximesterona/administração & dosagem , Fluoximesterona/efeitos adversos , Humanos , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Prednisona/administração & dosagem , Prednisona/efeitos adversos , Análise de Regressão , Tiotepa/administração & dosagem , Tiotepa/efeitos adversos , Falha de Tratamento , Vimblastina/administração & dosagem , Vimblastina/efeitos adversos , Vincristina/administração & dosagem , Vincristina/efeitos adversos
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