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1.
J Clin Invest ; 129(10): 4464-4476, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31524634

RESUMO

The prognostic value of immune cell infiltration within the tumor microenvironment (TME) has been extensively investigated via histological and genomic approaches. Based on the positive prognostic value of T cell infiltration, Immunoscore has been developed and validated for predicting risk of recurrence for colorectal cancer (CRC). Also, association between a consensus T helper 1 (Th-1) immune response and favorable clinical outcomes has been observed across multiple cancer types. Here, we reanalyzed public genomic data sets from The Cancer Genome Atlas (TCGA) and NCBI Gene Expression Omnibus (NCBI-GEO) and performed multispectral immunohistochemistry (IHC) on a cohort of colorectal tumors. We identified and characterized a risk group, representing approximately 10% of CRC patients, with high intratumoral CD8+ T cell infiltration, but poor prognosis. These tumors included both microsatellite instable (MSI) and stable (MSS) phenotypes and had a high density of tumor-associated macrophages (TAMs) that expressed CD274 (programmed death-ligand 1 [PD-L1]), TGF-ß activation, and an immune overdrive signature characterized by the overexpression of immune response and checkpoint genes. Our findings illustrate that CRC patients may have poor prognosis despite high CD8+ T cell infiltration and provide CD274 as a simple biomarker for identifying these patients.


Assuntos
Neoplasias Colorretais/imunologia , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/metabolismo , Antígenos CD8/genética , Antígenos CD8/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Estudos de Coortes , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Bases de Dados Genéticas , Expressão Gênica , Humanos , Imuno-Histoquímica , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Macrófagos/imunologia , Macrófagos/patologia , Melanoma/genética , Melanoma/imunologia , Melanoma/patologia , Instabilidade de Microssatélites , Fenótipo , Prognóstico , Fatores de Risco
2.
Diabetologia ; 61(4): 954-958, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29128936

RESUMO

AIMS/HYPOTHESIS: Diabetes research studies routinely rely upon the use of tissue samples from human organ donors. It remains unclear whether the length of hospital stay prior to organ donation affects the presence of cells infiltrating the pancreas or the frequency of replicating beta cells. METHODS: To address this, 39 organ donors without diabetes were matched for age, sex, BMI and ethnicity in groups of three. Within each group, donors varied by length of hospital stay immediately prior to organ donation (<3 days, 3 to <6 days, or ≥6 days). Serial sections from tissue blocks in the pancreas head, body and tail regions were immunohistochemically double stained for insulin and CD45, CD68, or Ki67. Slides were electronically scanned and quantitatively analysed for cell positivity. RESULTS: No differences in CD45+, CD68+, insulin+, Ki67+ or Ki67+/insulin+ cell frequencies were found when donors were grouped according to duration of hospital stay. Likewise, no interactions were observed between hospitalisation group and pancreas region, age, or both; however, with Ki67 staining, cell frequencies were greater in the body vs the tail region of the pancreas (∆ 0.65 [unadjusted 95% CI 0.25, 1.04]; p = 0.002) from donors <12 year of age. Interestingly, frequencies were less in the body vs tail region of the pancreas for both CD45+ cells (∆ -0.91 [95% CI -1.71, -0.10]; p = 0.024) and insulin+ cells (∆ -0.72 [95% CI -1.10, -0.34]; p < 0.001). CONCLUSIONS/INTERPRETATION: This study suggests that immune or replicating beta cell frequencies are not affected by the length of hospital stay prior to donor death in pancreases used for research. DATA AVAILABILITY: All referenced macros (adopted and developed), calculations, programming code and numerical dataset files (including individual-level donor data) are freely available on GitHub through Zenodo at https://doi.org/10.5281/zenodo.1034422.


Assuntos
Hospitalização , Tempo de Internação , Transplante de Pâncreas , Pâncreas/patologia , Adolescente , Índice de Massa Corporal , Criança , Morte , Diabetes Mellitus/patologia , Feminino , Humanos , Imuno-Histoquímica , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Resultado do Tratamento , Adulto Jovem
3.
Pancreas ; 46(2): 252-259, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27984510

RESUMO

OBJECTIVES: Attaining high-quality RNA from the tissues or organs of deceased donors used for research can be challenging due to physiological and logistical considerations. In this investigation, METHODS: RNA Integrity Number (RIN) was determined in pancreatic samples from 236 organ donors and used to define high (≥6.5) and low (≤4.5) quality RNAs. Logistic regression was used to evaluate the potential effects of novel or established organ and donor factors on RIN. RESULTS: Univariate analysis revealed donor cause of death (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.15-0.77; P = 0.01), prolonged tissue storage before RNA extraction (OR, 0.65; 95% CI, 0.52-0.79; P < 0.01), pancreas region sampled (multiple comparisons, P < 0.01), and sample type (OR, 0.32; 95% CI, 0.15-0.67; P < 0.01) negatively influenced outcome. Conversely, duration of final hospitalization (OR, 3.95; 95% CI, 1.59-10.37; P < 0.01) and sample collection protocol (OR, 8.48; 95% CI, 3.96-19.30; P < 0.01) positively impacted outcome. Islet RNA obtained via laser capture microdissection improved RIN when compared with total pancreatic RNA from the same donor (ΔRIN = 1.3; 95% CI, 0.6-2.0; P < 0.01). CONCLUSIONS: A multivariable model demonstrates that autopsy-free and biopsy-free human pancreata received, processed, and preserved at a single center, using optimized procedures, from organ donors dying of anoxia with normal lipase levels increase the odds of obtaining high-quality RNA.


Assuntos
Pâncreas/metabolismo , Estabilidade de RNA , RNA/metabolismo , Doadores de Tecidos , Adolescente , Adulto , Autopsia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , RNA/genética , RNA/isolamento & purificação , Adulto Jovem
5.
Cancer Chemother Pharmacol ; 76(5): 897-907, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26362045

RESUMO

BACKGROUND: The California Cancer Consortium completed a phase I trial of E7389 (eribulin mesylate), an analog of the marine natural product halichondrin B. This trial was to determine the pharmacodynamics, pharmacokinetics, and MTD of E7389 administered by bolus injection weekly for 3 weeks out of four. METHODS: This trial included a rapid titration design. Real-time pharmacokinetics were utilized to guide dose escalation. Initially, single-patient cohorts were enrolled with intra- and inter-patient dose doubling. The second phase was a standard 3 + 3 dose escalation schedule. At the MTD, a cohort of patients was enrolled for target validation studies (separate manuscript). The starting dose was 0.125 mg/m(2), and doses were doubled within and between patients in the first phase. Blood and urine sampling for E7389 pharmacokinetics was performed on doses 1 and 3 of cycle 1. Levels were determined using a LC/MS/MS assay. RESULTS: Forty patients were entered. Thirty-eight were evaluable for toxicity and 35 for response. The rapid escalation ended with a grade 3 elevation of alkaline phosphatase at 0.5 mg/m(2)/week. The second phase ended at 2.0 mg/m(2)/week with dose-limiting toxicities of grades 3 and 4 febrile neutropenia. Other toxicities included hypoglycemia, hypophosphatemia, and fatigue. The MTD was 1.4 mg/m(2)/week. Responses included four partial responses (lung cancer [2], urothelial [1], and melanoma [1]). CONCLUSIONS: E7389 was well tolerated in this trial with the major toxicity being myelosuppression. PD shows that E7389 induces significant morphologic changes (bundle formation) in the microtubules of peripheral blood mononuclear cells and tumor cells in vivo. The data suggest that lower intra-tumoral levels of ß-tubulin III or higher intra-tumoral levels of MAP4 may correlate with response to E7389, while lower intra-tumoral levels of stathmin may be associated with progression. PK data reveal that E7389 exhibits a tri-exponential elimination from the plasma of patients receiving a rapid i.v. infusion. At sub-toxic doses, plasma concentrations of E7389 are maintained well above the levels required for activity in vitro for >72 h.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Furanos/farmacologia , Cetonas/farmacologia , Moduladores de Tubulina/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Neoplasias da Mama/sangue , Neoplasias da Mama/tratamento farmacológico , Carcinoma/sangue , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos , Neutropenia Febril/induzido quimicamente , Feminino , Furanos/efeitos adversos , Furanos/sangue , Furanos/farmacocinética , Furanos/uso terapêutico , Humanos , Injeções Intravenosas , Cetonas/efeitos adversos , Cetonas/sangue , Cetonas/farmacocinética , Cetonas/uso terapêutico , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/tratamento farmacológico , Linfopenia/induzido quimicamente , Masculino , Melanoma/sangue , Melanoma/tratamento farmacológico , Pessoa de Meia-Idade , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/tratamento farmacológico , Terapia de Salvação , Moduladores de Tubulina/efeitos adversos , Moduladores de Tubulina/sangue , Moduladores de Tubulina/farmacocinética , Moduladores de Tubulina/uso terapêutico , Neoplasias Urológicas/sangue , Neoplasias Urológicas/tratamento farmacológico
6.
Clin Cancer Res ; 19(13): 3631-9, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23653147

RESUMO

PURPOSE: Pazopanib is a potent, multitargeted receptor tyrosine kinase inhibitor; however, there is limited information regarding the effects of liver function on pazopanib metabolism and pharmacokinetics. The objective of this study was to establish the maximum-tolerated dose (MTD) and pharmacokinetic profile of pazopanib in patients with varying degrees of hepatic dysfunction. EXPERIMENTAL DESIGN: Patients with any solid tumors or lymphoma were stratified into four groups based on the degree of hepatic dysfunction according to the National Cancer Institute Organ Dysfunction Working Group (NCI-ODWG) criteria. Pazopanib was given orally once a day on a 21-day cycle. A modified 3+3 design was used. RESULTS: Ninety-eight patients were enrolled. Patients in the mild group tolerated 800 mg per day. The moderate and severe groups tolerated 200 mg per day. Pharmacokinetic data in the mild group were similar to the data in the normal group. Comparison of the median Cmax and area under the curve [AUC(0-24)] in the moderate or severe groups at 200 mg per day to the values in the normal and mild groups at 800 mg per day indicated less than dose-proportional systemic exposures in patients with moderate and severe hepatic impairment. This suggests that the lower maximum-tolerated dose in the moderate and severe group is not due to a decrease in drug clearance or alteration in the proportion of metabolites. CONCLUSIONS: In patients with mild liver dysfunction, pazopanib is well tolerated at the Food and Drug Administration (FDA)-approved dose of 800 mg per day. Patients with moderate and severe liver dysfunction tolerated 200 mg per day.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Hepatopatias/etiologia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Pirimidinas/uso terapêutico , Sulfonamidas/uso terapêutico , Adulto , Idoso , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Feminino , Humanos , Indazóis , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias/complicações , Pirimidinas/efeitos adversos , Pirimidinas/farmacocinética , Sulfonamidas/efeitos adversos , Sulfonamidas/farmacocinética , Resultado do Tratamento , Adulto Jovem
7.
J Immunol ; 190(7): 3276-88, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23440410

RESUMO

NOD mice exhibit major defects in the earliest stages of T cell development in the thymus. Genome-wide genetic and transcriptome analyses were used to investigate the origins and consequences of an early T cell developmental checkpoint breakthrough in Rag1-deficient NOD mice. Quantitative trait locus analysis mapped the presence of checkpoint breakthrough cells to several known NOD diabetes susceptibility regions, particularly insulin-dependent diabetes susceptibility genes (Idd)9/11 on chromosome 4, suggesting common genetic origins for T cell defects affecting this trait and autoimmunity. Genome-wide RNA deep-sequencing of NOD and B6 Rag1-deficient thymocytes revealed the effects of genetic background prior to breakthrough, as well as the cellular consequences of the breakthrough. Transcriptome comparison between the two strains showed enrichment in differentially expressed signal transduction genes, prominently tyrosine kinase and actin-binding genes, in accord with their divergent sensitivities to activating signals. Emerging NOD breakthrough cells aberrantly expressed both stem cell-associated proto-oncogenes, such as Lmo2, Hhex, Lyl1, and Kit, which are normally repressed at the commitment checkpoint, and post-ß-selection checkpoint genes, including Cd2 and Cd5. Coexpression of genes characteristic of multipotent progenitors and more mature T cells persists in the expanding population of thymocytes and in the thymic leukemias that emerge with age in these mice. These results show that Rag1-deficient NOD thymocytes have T cell defects that can collapse regulatory boundaries at two early T cell checkpoints, which may predispose them to both leukemia and autoimmunity.


Assuntos
Transformação Celular Neoplásica/genética , Proteínas de Homeodomínio/genética , Células Precursoras de Linfócitos T/metabolismo , Actinas/metabolismo , Fatores Etários , Animais , Transformação Celular Neoplásica/imunologia , Mapeamento Cromossômico , Cromossomos de Mamíferos , Análise por Conglomerados , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Linfoma/genética , Linfoma/imunologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Células Precursoras de Linfócitos T/imunologia , Locos de Características Quantitativas , Transdução de Sinais , Células-Tronco/metabolismo , Timócitos/imunologia , Timócitos/metabolismo , Transcrição Gênica
8.
J Virol ; 85(6): 2878-90, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21191005

RESUMO

The use of animal models of human cytomegalovirus (HCMV) infection is critical to refine HCMV vaccine candidates. Previous reports have demonstrated that immunization of rhesus monkeys against rhesus cytomegalovirus (RhCMV) can reduce both local and systemic replication of RhCMV following experimental RhCMV challenge. These studies used prime/boost combinations of DNA expression plasmids alone or DNA priming and boosting with either inactivated virion particles or modified vaccinia virus Ankara (MVA) expressing the same antigens. Viral outcomes included reduced RhCMV replication at the site of subcutaneous inoculation and RhCMV viremia following intravenous inoculation. Since shedding of cytomegalovirus from mucosal surfaces is critical for horizontal transmission of the virus, DNA priming/MVA boosting was evaluated for the ability to reduce oral shedding of RhCMV following subcutaneous challenge. Of six rhesus monkeys vaccinated exclusively against RhCMV glycoprotein B (gB), phosphoprotein 65 (pp65), and immediate-early 1 (IE1), half showed viral loads in saliva that were lower than those of control monkeys by 1 to 3 orders of magnitude. Further, there was a strong association of memory pp65 T cell responses postchallenge in animals exhibiting the greatest reduction in oral shedding. These results highlight the fact that a DNA/MVA vaccination regimen can achieve a notable reduction in a critical parameter of viral replication postchallenge. The recently completed clinical trial of a gB subunit vaccine in which the rate of HCMV infection was reduced by 50% in the individuals receiving the vaccine is consistent with the results of this study suggesting that additional immunogens are likely essential for maximum protection in an outbred human population.


Assuntos
Infecções por Citomegalovirus/prevenção & controle , Vacinas contra Citomegalovirus/imunologia , Doenças dos Primatas/prevenção & controle , Vacinas de DNA/imunologia , Eliminação de Partículas Virais , Animais , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Vacinas contra Citomegalovirus/administração & dosagem , Modelos Animais de Doenças , Feminino , Imunização Secundária/métodos , Macaca mulatta , Masculino , Mucosa Bucal/virologia , Doenças dos Primatas/imunologia , Doenças dos Primatas/virologia , Saliva/virologia , Vacinação/métodos , Vacinas de DNA/administração & dosagem , Carga Viral
9.
Contemp Clin Trials ; 32(1): 114-21, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20923709

RESUMO

PURPOSE: This paper introduces the target equivalence range (TEQR) design, a frequentist implementation of the modified toxicity probability interval (mTPI) design, as a competitor to the standard 3+3 design (3+3). The 3+3 is the work horse design in Phase I. It is good at determining if a safe dose exits, but provides poor accuracy and precision in estimating the level of toxicity at the maximum tolerated dose (MTD). Its main competitor, the continual reassessment method (CRM) has not found a true niche in the Phase I armamentarium resulting from statistical and implementation complexities. METHODS: We describe the four competing designs (3+3, mTPI, CRM, and TEQR), comparing them based on i) operating characteristics from simulated trials, and ii) ease of implementation. RESULTS: The TEQR is better than the 3+3 when compared on; 1) number of times the dose at or nearest the target toxicity level was selected as the MTD, 2) number of patients assigned to dose levels at or nearest the MTD, 3) overall trial dose limiting toxicity rate and 4) accuracy and precision of estimates for the rate of toxicity at the MTD. Further it is reasonably comparable to the CRM and mTPI on 1-3. CONCLUSION: The TEQR offers trial designers a competitor to the 3+3 for ease of implementation with better operating characteristics and the added attraction of a glimpse of activity at the MTD. The R package TEQR, freely available from the comprehensive R archive network, includes functions to calculate dose escalation guidelines and operating characteristics.


Assuntos
Ensaios Clínicos Fase I como Assunto/métodos , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Dose Máxima Tolerável , Algoritmos , Humanos , Probabilidade , Projetos de Pesquisa
10.
PLoS One ; 5(12): e14318, 2010 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-21187953

RESUMO

We describe three statistical results that we have found to be useful in case-control genetic association testing. All three involve combining the discovery of novel genetic variants, usually by sequencing, with genotyping methods that recognize previously discovered variants. We first consider expanding the list of known variants by concentrating variant-discovery in cases. Although the naive inclusion of cases-only sequencing data would create a bias, we show that some sequencing data may be retained, even if controls are not sequenced. Furthermore, for alleles of intermediate frequency, cases-only sequencing with bias-correction entails little if any loss of power, compared to dividing the same sequencing effort among cases and controls. Secondly, we investigate more strongly focused variant discovery to obtain a greater enrichment for disease-related variants. We show how case status, family history, and marker sharing enrich the discovery set by increments that are multiplicative with penetrance, enabling the preferential discovery of high-penetrance variants. A third result applies when sequencing is the primary means of counting alleles in both cases and controls, but a supplementary pooled genotyping sample is used to identify the variants that are very rare. We show that this raises no validity issues, and we evaluate a less expensive and more adaptive approach to judging rarity, based on group-specific variants. We demonstrate the important and unusual caveat that this method requires equal sample sizes for validity. These three results can be used to more efficiently detect the association of rare genetic variants with disease.


Assuntos
Genótipo , Alelos , Axônios , Estudos de Casos e Controles , Mapeamento Cromossômico , Saúde da Família , Frequência do Gene , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Modelos Estatísticos , Fenótipo , Distribuição de Poisson , Projetos de Pesquisa , Análise de Sequência de DNA
11.
Am J Clin Oncol ; 31(4): 317-22, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18845988

RESUMO

PURPOSE: Prolonged survival for patients with unresectable hepatocellular carcinoma (HCC) is consistently reported at lower than 6 months. Oxaliplatin has recently demonstrated activity in HCC. The objective of this study was to determine the response rate, survival, time to progression, and toxicity in patients with poor prognosis HCC when treated with oxaliplatin. EXPERIMENTAL DESIGN: Patients were required to have measurable recurrent, metastatic or unresectable HCC, and to have previously been exposed to no more than 2 prior chemotherapy regimens. Karnofsky performance of 70% or above and adequate organ and hematologic function were required. All patients received treatment with oxaliplatin 100 mg/m on day 1 and 15 as a 2-hour intravenous infusion and were pretreated with antiemetics. Treatment was repeated every 28 days. RESULTS: Thirty-six patients were enrolled and evaluated, although 6 expired before the first planned evaluation. Karnofsky performance status was 70/80/90/100% in 5/9/9/13 patients, respectively. The median time to progression was 2 months; median survival was 6 months. The 6-month overall survival was 55% (95% confidence interval 41%-74%), and the 6 month event-free survival was 11% (95% confidence interval 4%-28%). CONCLUSION: Single agent, oxaliplatin, has produced one partial response of good duration in 36 patients, but failed to meet the a priori criterion for promise in this trial. Sixteen patients were observed to have stable disease with a well tolerated toxicity profile. The combination of oxaliplatin and other agents should be considered to treat HCC in those patients with good functional status.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Compostos Organoplatínicos/uso terapêutico , Terapia de Salvação , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/secundário , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/secundário , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/secundário , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Oxaliplatina , Prognóstico , Taxa de Sobrevida , Resultado do Tratamento
12.
Mamm Genome ; 15(3): 199-209, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15014969

RESUMO

We have developed an imprinting assay combining the use of mice carrying maternal or paternal duplication of chromosomal regions of interest with custom oligonucleotide microarrays. As a model system, we analyzed RNA from CNS tissue of neonatal mice carrying the reciprocal translocation T(7;15)9H and uniparental duplication of proximal Chr 7 and 15. The duplicated region includes the locus on proximal Chr 7 corresponding to the human Prader-Willi/Angelman Syndrome. The microarray contained 322 oligonucleotides, including probes to detect major genes involved in neural excitability and synaptic transmission, as well as known imprinted genes mapping to proximal Chr 7: Ndn, Snrpn, Mkrn3, Magel2, Peg3, and Ube3a. Imprinting of these genes in neonatal cortex and cerebellum was first confirmed by quantitative RT-PCR. Their inclusion on the microarray thus provided positive controls for evaluating the effect of background on the sensitivity of the assay, and for establishing the minimum level of expression required to detect imprinting. Our analysis extended previous work by revealing bi-allelic expression in CNS tissue of those queried genes mapping to proximal Chr 7 or 15, including the Gabrb3 gene, for which there have been conflicting reports. Microarray analysis also revealed no effect of the maternal or paternal disomy on expression levels of the unlinked genes detected, including those potentially implicated in the Prader-Willi or Angelman Syndrome. In addition, quantitative RT-PCR revealed a gene dosage effect in both cerebellum and cortex for all of the known imprinted genes assayed, except for Ube3a in cerebellum.


Assuntos
Impressão Genômica/genética , Camundongos/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA/genética , Dissomia Uniparental/genética , Animais , Sistema Nervoso Central/metabolismo , Primers do DNA , Dosagem de Genes , Expressão Gênica , Camundongos Mutantes , RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Cancer Res ; 64(3): 962-8, 2004 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-14871826

RESUMO

Two glutathione peroxidase (GPX) isozymes, GPX-1 and GPX-2 (GPX-GI), are the major enzymes that reduce hydroperoxides in intestinal epithelium. We have previously demonstrated that targeted disruption of both the Gpx1 and Gpx2 genes (GPX-DKO) results in a high incidence of ileocolitis in mice raised under conventional conditions, which include the harboring of Helicobacter species [non-specific-pathogen-free (non-SPF) conditions]. In this study, we have characterized GPX-DKO mice that have microflora-associated intestinal cancers, which are correlated with increased intestinal pathology/inflammation. We found that GPX-DKO mice raised under germ-free conditions have virtually no pathology or tumors. After colonizing germ-free mice with commensal microflora without any known pathogens (SPF), <9% of GPX-DKO mice develop tumors in the ileum or the colon. However, about one-fourth of GPX-DKO mice raised under non-SPF conditions from birth or transferred from SPF conditions at weaning have predominantly ileal tumors. Nearly 30% of tumors are cancerous; most are invasive adenocarcinomas and a few signet-ring cell carcinomas. On the basis of these results, we conclude that GPX-DKO mice are highly susceptible to bacteria-associated inflammation and cancer. The sensitivity exhibited in these mice suggests that peroxidative stress plays an important role in ileal and colonic pathology and inflammation, which can lead to tumorigenesis.


Assuntos
Glutationa Peroxidase/genética , Neoplasias Intestinais/genética , Neoplasias Intestinais/microbiologia , Animais , Doença de Crohn/complicações , Doença de Crohn/enzimologia , Doença de Crohn/genética , Doença de Crohn/microbiologia , Feminino , Neoplasias Intestinais/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Organismos Livres de Patógenos Específicos , Glutationa Peroxidase GPX1
14.
Mol Cell Biol ; 23(7): 2362-78, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12640121

RESUMO

Antioxidant enzymes are critical in oxidative stress responses. Radioresistant variants isolated from MCF-7 human carcinoma cells following fractionated ionizing radiation (MCF+FIR cells) or overexpression of manganese superoxide dismutase (MCF+SOD cells) demonstrated dose-modifying factors at 10% isosurvival of 1.8 and 2.3, respectively. MCF+FIR and MCF-7 cells (exposed to single-dose radiation) demonstrated 5- to 10-fold increases in MnSOD activity, mRNA, and immunoreactive protein. Radioresistance in MCF+FIR and MCF+SOD cells was reduced following expression of antisense MnSOD. DNA microarray analysis and immunoblotting identified p21, Myc, 14-3-3 zeta, cyclin A, cyclin B1, and GADD153 as genes constitutively overexpressed (2- to 10-fold) in both MCF+FIR and MCF+SOD cells. Radiation-induced expression of these six genes was suppressed in fibroblasts from Sod2 knockout mice (-/-) as well as in MCF+FIR and MCF+SOD cells expressing antisense MnSOD. Inhibiting NF-kappa B transcriptional activity in MCF+FIR cells, by using mutant I kappa B alpha, inhibited radioresistance as well as reducing steady-state levels of MnSOD, 14-3-3 zeta, GADD153, cyclin A, and cyclin B1 mRNA. In contrast, mutant I kappa B alpha was unable to inhibit radioresistance or reduce 14-3-3 zeta, GADD153, cyclin A, and cyclin B1 mRNAs in MCF+SOD cells, where MnSOD overexpression was independent of NF-kappa B. These results support the hypothesis that NF-kappa B is capable of regulating the expression of MnSOD, which in turn is capable of increasing the expression of genes that participate in radiation-induced adaptive responses.


Assuntos
Adaptação Fisiológica/efeitos da radiação , Adenocarcinoma/metabolismo , Adenocarcinoma/radioterapia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/radioterapia , Superóxido Dismutase/metabolismo , Proteínas 14-3-3 , Adaptação Fisiológica/fisiologia , Animais , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , Ciclina A/genética , Ciclina A/metabolismo , Ciclina B/genética , Ciclina B/metabolismo , Ciclina B1 , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Raios gama , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/fisiologia , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Proteínas I-kappa B/biossíntese , Proteínas I-kappa B/genética , Proteínas I-kappa B/farmacologia , Camundongos , Camundongos Knockout , Inibidor de NF-kappaB alfa , NF-kappa B/antagonistas & inibidores , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/metabolismo , Tolerância a Radiação/genética , Tolerância a Radiação/fisiologia , Tolerância a Radiação/efeitos da radiação , Superóxido Dismutase/deficiência , Superóxido Dismutase/genética , Fator de Transcrição CHOP , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo
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