Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

País/Região como assunto
Intervalo de ano de publicação
1.
Lab Invest ; 101(8): 1098-1109, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33859335

RESUMO

Steatosis is the most important prognostic histologic feature in the setting of liver procurement. The currently utilized diagnostic methods, including gross evaluation and frozen section examination, have important shortcomings. Novel techniques that offer advantages over the current tools could be of significant practical utility. The aim of this study is to evaluate the accuracy of surface color spectrophotometry in the quantitative assessment of steatosis in a murine model of fatty liver. C57BL/6 mice were divided into a control group receiving normal chow (n = 19), and two steatosis groups receiving high-fat diets for up to 20 weeks-mild steatosis (n = 10) and moderate-to-severe steatosis (n = 19). Mouse liver surfaces were scanned with a hand-held spectrophotometer (CM-600D; Konica-Minolta, Osaka, Japan). Spectral reflectance data and color space values (L*a*b*, XYZ, L*c*h*, RBG, and CMYK) were correlated with histopathologic steatosis evaluation by visual estimate, digital image analysis (DIA), as well as biochemical tissue triglyceride measurement. Spectral reflectance and most color space values were very strongly correlated with histologic assessment of total steatosis, with the best predictor being % reflectance at 700 nm (r = 0.91 [0.88-0.94] for visual assessment, r = 0.92 [0.88-0.95] for DIA of H&E slides, r = 0.92 [0.87-0.95] for DIA of oil-red-O stains, and r = 0.78 [0.63-0.87] for biochemical tissue triglyceride measurement, p < 0.0001 for all). Several spectrophotometric parameters were also independently predictive of large droplet steatosis. In conclusion, hepatic steatosis can accurately be assessed using a portable, commercially available hand-held spectrophotometer device. If similarly accurate in human livers, this technique could be utilized as a point-of-care tool for the quantitation of steatosis, which may be especially valuable in assessing livers during deceased donor organ procurement.


Assuntos
Fígado Gorduroso , Fígado , Espectrofotometria/métodos , Animais , Modelos Animais de Doenças , Fígado Gorduroso/diagnóstico por imagem , Fígado Gorduroso/patologia , Técnicas Histológicas , Fígado/diagnóstico por imagem , Fígado/patologia , Transplante de Fígado , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Espectrofotometria/instrumentação
2.
Am J Transplant ; 13(1): 76-85, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23072543

RESUMO

Renal transplant candidates with high levels of donor-specific anti-HLA antibodies have low transplantation rates and high mortality rates on dialysis. Using desensitization protocols, good short-term outcomes are possible in "positive crossmatch kidney transplants (+XMKTx)", but long-term outcome data are lacking. The aim of the current study was to determine actual 5-year graft outcomes of +XMKTx. We compared graft survival and the functional and histologic status of 102 +XMKTx to 204 -XMKTx matched for age and sex. Actual 5-year death-censored graft survival was lower in the +XMKTx group (70.7% vs. 88.0%, p < 0.01) and chronic injury (glomerulopathy) was present in 54.5% of surviving grafts. Graft survival was higher in recipients with antibody against donor class I only compared with antibody against class II (either alone or in combination with class I) (85.3% vs. 62.6%, p = 0.05) and was similar to -XMKTx (85.3 vs. 88.0%, p = 0.64). Renal function and proteinuria ranged across a wide spectrum in all groups reflecting the different histological findings at 5 years. We conclude that when compared to -XMKTx, +XMKTx have inferior outcomes at 5 years, however, almost half of the surviving grafts do not have glomerulopathy and avoiding antibodies against donor class II may improve outcomes.


Assuntos
Transplante de Rim , Adulto , Estudos de Casos e Controles , Sobrevivência de Enxerto , Teste de Histocompatibilidade , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento
3.
J Exp Med ; 182(5): 1369-76, 1995 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-7595207

RESUMO

We investigated the expression and distribution of keratinocyte growth factor (KGF) (FGF-7) and its receptor (KGFR) during reepithelialization of human skin. KGF mRNA levels increased rapidly by 8-10-fold and remained elevated for several days. In contrast, KGFR transcript levels decreased early but were significantly elevated by 8-9 d. A KGF-immunoglobulin G fusion protein (KGF-HFc), which specifically and sensitively detects the KGFR, localized the receptor to differentiating keratinocytes of control epidermis, but revealed a striking decrease in receptor protein expression during the intermediate period of reepithelization. Suramin, which blocked KGF binding and stripped already bound KGF from its receptor, failed to unmask KGFRs in tissue sections from the intermediate phase of wound repair. The absence of KGFR protein despite increased KGFR transcript levels implies functional receptor downregulation in the presence of increased KGF. This temporal modulation of KGF and KGFRs provides strong evidence for the functional involvement of KGF in human skin reepithelialization.


Assuntos
Epiderme/fisiologia , Fatores de Crescimento de Fibroblastos , Substâncias de Crescimento/biossíntese , Receptores de Fatores de Crescimento de Fibroblastos , Receptores de Fatores de Crescimento/biossíntese , Cicatrização/genética , Adulto , Diferenciação Celular , Regulação para Baixo , Epiderme/efeitos dos fármacos , Fator 10 de Crescimento de Fibroblastos , Fator 7 de Crescimento de Fibroblastos , Regulação da Expressão Gênica/efeitos dos fármacos , Genes de Imunoglobulinas , Humanos , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Proteínas Recombinantes de Fusão/biossíntese , Transplante de Pele , Suramina/farmacologia
4.
J Cell Biol ; 125(2): 393-401, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8163555

RESUMO

In vitro studies have shown that keratinocyte growth factor (KGF, also known as FGF-7) is secreted by fibroblasts and is mitogenic specifically for epithelial cells. Therefore, KGF may be an important paracrine mediator of epithelial cell proliferation in vivo. Because stromal cells are thought to influence glandular proliferation in the primate endometrium, we investigated the hormonal regulation and cellular localization of KGF mRNA expression in the rhesus monkey uterus. Tissues were obtained both from naturally cycling monkeys in the follicular and luteal phases of the cycle, and from spayed monkeys that were either untreated or treated with estradiol (E2) alone, E2 followed by progesterone (P), E2 plus P, or E2 plus P plus an antiprogestin (RU 486). Northern blot analysis of total RNA with 32P-labeled probes revealed that the level of KGF mRNA in the endometrium was 70-100-fold greater in the luteal phase or after P treatment than in untreated, E2-treated, or follicular phase animals. Northern analysis also showed that KGF mRNA was present in the myometrium but was unaffected by hormonal state. RU 486 treatment prevented the P-induced elevation of endometrial KGF mRNA. P-dependent elevation of endometrial KGF expression was confirmed by measurement of KGF protein in tissue extracts using a two-site enzyme-linked immunosorbent assay. In situ hybridization with nonradioactive digoxigenin-labeled cDNA probes revealed that the KGF mRNA signal, which was present only in stromal and smooth muscle cells, was substantially increased by P primarily in the stromal cells located in the basalis region. Smooth muscle cells in the myometrium and the walls of the spiral arteries also expressed KGF mRNA, but the degree of this expression did not differ with hormonal state. P treatment led to increased proliferation in the glandular epithelium of the basalis region and to extensive growth of the spiral arteries. We conclude that the P-dependent increase in endometrial KGF resulted from a dual action of P: (a) a P-dependent induction of KGF expression in stromal cells, especially those in the basalis (zones III and IV), and (b) a P-dependent increase in the number of KGF-positive vascular smooth muscle cells caused by the proliferation of the spiral arteries. KGF is one of the first examples in primates of a P-induced, stromally derived growth factor that might function as a progestomedin.


Assuntos
Endométrio/metabolismo , Fatores de Crescimento de Fibroblastos , Substâncias de Crescimento/biossíntese , Progesterona/fisiologia , Animais , Northern Blotting , Divisão Celular , Linhagem Celular , Endométrio/irrigação sanguínea , Endométrio/citologia , Estradiol/fisiologia , Estro , Feminino , Fator 10 de Crescimento de Fibroblastos , Fator 7 de Crescimento de Fibroblastos , Substâncias de Crescimento/genética , Humanos , Hibridização In Situ , Macaca mulatta , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , RNA Mensageiro/biossíntese , Células Estromais/metabolismo , Útero/metabolismo
5.
Science ; 254(5036): 1382-5, 1991 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-1720571

RESUMO

We identified a naturally occurring hepatocyte growth factor (HGF) variant, whose predicted sequence extends only through the second kringle domain of this plasminogen-related molecule. This smaller molecule, derived from an alternative HGF transcript, lacked mitogenic activity but specifically inhibited HGF-induced mitogenesis. Cross-linking studies demonstrated that the truncated molecule competes with HGF for binding to the HGF receptor, which has been identified as the c-met protooncogene product. Thus, the same gene encodes both a growth factor and its direct antagonist.


Assuntos
Substâncias de Crescimento/genética , Transcrição Gênica , Sequência de Aminoácidos , Sequência de Bases , Northern Blotting , Linhagem Celular , Meios de Cultura , DNA/genética , Replicação do DNA/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Substâncias de Crescimento/isolamento & purificação , Substâncias de Crescimento/farmacologia , Fator de Crescimento de Hepatócito , Humanos , Cinética , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Plasmídeos , Poli A/genética , Poli A/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , RNA/genética , RNA/isolamento & purificação , RNA Mensageiro , Timidina/metabolismo , Transfecção
6.
Ann Burns Fire Disasters ; 32(3): 216-221, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32313536

RESUMO

Burn injuries are serious lesions requiring specialized medical care, and are associated with prolonged length of hospital stay (LOS). This study aims to elucidate the epidemiological and clinical factors affecting the LOS of pediatric and adult patients with burn wounds. A single-centre retrospective study was conducted at the Hopital Libanais Geitawi Burn Centre in Lebanon. Medical records of patients admitted to the centre between January 2014 and December 2018 were retrieved. Epidemiological and clinical data, such as age, gender, LOS, co-morbidities, and clinical burn and operative characteristics were collected and subjected to statistical analysis. A total of 321 adult and 154 pediatric patients met the inclusion criteria. Mean LOS in the total population was 23.58 days. Univariate analysis revealed inconsistent correlations between the studied factors and the LOS of pediatric and adult patients. Factors positively affecting both populations were: undergoing an operation, number of operations, burn degree, infection, blood transfusion, and need for burn excision and grafting. Additionally, among pediatric patients LOS significantly increased with age, total body surface area (TBSA) burn wound, cause of burn, sepsis, wound dressing under anaesthesia, and escharotomy. On the other hand, female gender and fever were significant additional positive influencers of adult LOS. Multivariate analysis showed that both pediatric and adult LOS was significantly associated to number of operations, need for burn excision and skin grafting, and receiving a blood transfusion. Adult LOS was further affected by mechanical ventilation, infection and age. Our study demonstrated the differential influence of epidemiological and clinical factors among adult and pediatric populations, which allows better prediction of LOS and management of patients with burn injuries.


Les brûlures sont des pathologies sévères nécessitant une prise en charge spécialisée avec des durées de séjour élevées. Cette étude a pour but de préciser les facteurs épidémiologiques et cliniques influençant la durée de séjour, chez les adultes (321) et les enfants (154) brûlés. Elle a été réalisée dans le CTB de l'hôpital libanais Geitawi, en utilisant les dossiers des patients hospitalisés entre janvier 2014 et décembre 2018. Nous avons colligé et comparé le sexe, l'âge, la durée moyenne de séjour (DMS), les comorbidités, les données cliniques concernant la brûlure y compris la nécessité de chirurgie. La DMS était de 23,58 j. L'analyse univariée a retrouvé des paramètres influençant la DMS différents chez les enfants et les adultes. La DMS augmentait, dans les 2 populations, avec la nécessité de chirurgie (excision/greffe) et le nombre d'interventions, la profondeur de la brûlure, la survenue d'infection, la transfusion. Chez les enfants, on trouvait en plus l'augmentation de l'âge, la surface brûlée, certaines causes de brûlure, les incisions de décharge et les pansements sous AG. Chez l'adulte, la DMS augmentait chez les femmes et les patients fébriles. En analyse multivariée, le nombre d'interventions (excisions et greffes) et la transfusion restaient corrélés à l'augmentation de DMS. Chez l'adulte, l'infection, la ventilation mécanique et l'âge étaient 3 autres paramètres significatifs. Cette étude montre qu'il existe des paramètres différents corrélés à l'augmentation de DMS dans les populations brûlées d'adultes et d'enfants, ce qui permet une évaluation plus fine de la charge de soins et de la DMS à l'admission d'un brûlé.

7.
Mol Cell Biol ; 10(7): 3824-7, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2192264

RESUMO

Expression of a highly specific protein inhibitor for cyclic AMP-dependent protein kinases in interleukin-1 (IL-1)-responsive cells blocked IL-1-induced gene transcription that was driven by the kappa immunoglobulin enhancer or the human immunodeficiency virus long terminal repeat. This inhibitor did not affect protein kinase C-mediated gene transcription, suggesting that cyclic AMP-dependent protein kinases are involved in the signal transduction pathway for IL-1 in a number of responsive cell types.


Assuntos
Proteínas de Transporte/genética , Inibidores Enzimáticos , Interleucina-1/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas Quinases/metabolismo , Transdução de Sinais , Transcrição Gênica , Linhagem Celular , Colforsina/farmacologia , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Humanos , Células Matadoras Naturais , NF-kappa B , Inibidores de Proteínas Quinases , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos
8.
Mol Cell Biol ; 9(3): 959-64, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2542770

RESUMO

Interleukin 1 (IL-1) induces the synthesis of kappa immunoglobulin light chains and the expression of surface immunoglobulin in the murine pre-B-cell line 70Z/3 (J. G. Giri, P. W. Kincade, and S. B. Mizel, J. Immunol. 132:223-228, 1984). In the present study, we found that these effects of IL-1 are mimicked by cyclic AMP (cAMP) analogs and cAMP-elevating drugs. The induction of kappa immunoglobulin light-chain gene expression by IL-1 was associated with an increase in intracellular cAMP levels. Incubation of 70Z/3 cells with IL-1 or cAMP resulted in the activation of the kappa immunoglobulin enhancer, as detected by the induction of chloramphenicol acetyltransferase (CAT) in cells transfected with a kappa enhancer-CAT expression plasmid. In contrast, CAT plasmids lacking a kappa immunoglobulin enhancer were inactive in the presence of IL-1 or cAMP. Furthermore, IL-1 and cAMP analogs and inducers were found to induce the activation of a NF-kappa B-like DNA-binding protein that exhibited specificity for the kappa immunoglobulin enhancer. These results suggest that cAMP may play an important role as a second messenger for IL-1 in the induction of kappa immunoglobulin light-chain synthesis in pre-B cells via the activation of a DNA-binding protein that is similar or identical to NF-kappa B.


Assuntos
AMP Cíclico/farmacologia , Proteínas de Ligação a DNA/metabolismo , Genes de Imunoglobulinas/efeitos dos fármacos , Interleucina-1/farmacologia , Fatores de Transcrição/metabolismo , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linhagem Celular , AMP Cíclico/metabolismo , Elementos Facilitadores Genéticos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Cadeias kappa de Imunoglobulina/biossíntese , Cadeias kappa de Imunoglobulina/genética , Camundongos , NF-kappa B
9.
Mol Cell Biol ; 13(2): 762-8, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8423800

RESUMO

Using an expression cDNA cloning approach, we examined human tumor cell lines for novel oncogenes that might evade detection by conventional techniques. We isolated a transforming sequence that was highly efficient in transforming NIH 3T3 mouse fibroblasts. DNA sequence analysis identified the gene as the human homolog of a recently cloned alpha subunit of mouse GTP-binding protein G alpha 12. NIH 3T3 cells transfected with G alpha 12 cDNA grew in soft agar and were tumorigenic in nude mice. There were no apparent mutations in the cloned cDNA in comparison with a G alpha 12 cDNA clone isolated from a normal human epithelial cell library, implying that overexpression alone was sufficient to cause NIH 3T3 cell transformation. The observed altered growth properties mediated by G alpha 12 showed a certain degree of dependency on serum factors, and its mitogenic potential was also potently inhibited by suramin treatment.


Assuntos
Transformação Celular Neoplásica/genética , Proteínas de Ligação ao GTP/genética , Células 3T3 , Sequência de Aminoácidos , Animais , Northern Blotting , Clonagem Molecular , DNA/biossíntese , DNA/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Proteínas de Ligação ao GTP/fisiologia , Biblioteca Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Oncogenes , Homologia de Sequência de Aminoácidos , Suramina/farmacologia , Células Tumorais Cultivadas
10.
Mol Cell Biol ; 14(2): 982-8, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7507208

RESUMO

Screening of a human embryonic lung fibroblast cDNA expression library with antiphosphotyrosine antibodies led to isolation of a novel protein kinase. A clone, designated A6, contained a 3-kb cDNA insert with a predicted open reading frame of 350 amino acids. DNA sequence analysis failed to reveal any detectable similarity with previously known genes, and the predicted A6 protein lacked any of the motifs commonly conserved in the catalytic domains of protein kinases. However, the bacterially expressed beta-galactosidase-A6 fusion protein demonstrated both tyrosine and serine phosphorylation in an in vitro kinase assay and phosphorylated exogenous substrates including myelin basic protein specifically on tyrosine residues. The enzyme also displayed biochemical properties analogous to those of other protein tyrosine kinases. The A6 gene was found to be expressed widely at the transcript level in normal tissues and was evolutionarily conserved. Thus, A6 represents a novel tyrosine kinase which is highly divergent from previously described members of this important class of regulatory molecules.


Assuntos
Expressão Gênica , Pulmão/enzimologia , Proteínas Tirosina Quinases/biossíntese , Sequência de Aminoácidos , Sequência de Bases , Northern Blotting , Western Blotting , Linhagem Celular , Clonagem Molecular , Embrião de Mamíferos , Escherichia coli , Feminino , Fibroblastos/enzimologia , Biblioteca Gênica , Humanos , Masculino , Dados de Sequência Molecular , Peso Molecular , Especificidade de Órgãos , Fosfotirosina , Biossíntese de Proteínas , Proteínas Tirosina Quinases/análise , Proteínas Tirosina Quinases/metabolismo , Proteínas Recombinantes/análise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Transcrição Gênica , Tirosina/análogos & derivados , Tirosina/análise
11.
Transplant Proc ; 49(4): 848-851, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28457409

RESUMO

BACKGROUND: There are only 4 prior studies reporting on outcomes of liver transplantation (LT) using Institutes Georges Lopez-1 (IGL-1) preservation solution. Detection of negative predictors of LT using IGL-1 may help finding strategies to protect selected recipients at higher risk of graft failure and death. METHODS: Review of all consecutive adult patients who underwent a first whole-graft LT using IGL-1 at authors' institution from 2013 to 2016. Primary end point was graft failure within the first 90 postoperative days (PODs). Graft losses due to any cause (including all deaths with a functioning graft) were recorded as graft failures. RESULTS: Of all 100 patients included in this study, 37 were women; median age was 58 years (range 18-71). There were 12 graft losses during the first 90 PODs (including 3 cases of primary nonfunction of the liver allograft), and 10 of the 12 graft losses occurred on first 30 PODs. All 12 patients who experienced graft loss (including 1 patient who underwent liver retransplantation) died within the first 90 PODs. Of the total 100 patients, 14 experienced biliary complications. Univariate analysis revealed prolonged warm ischemic time (WIT) as the only predictor of 90-day graft failure (odds ratio = 23.5, confidence interval = 1.29-430.18, P = .03). The cutoff by receiver operating characteristic curve for WIT was 38 minutes (area under the curve = 0.70). Positive predictive value for WIT >38 minutes was 94.3%. CONCLUSIONS: LT using IGL-1 can be performed safely. Similar to prior reports on LT using other preservation solutions, prolonged WIT was associated with adverse outcomes.


Assuntos
Transplante de Fígado/métodos , Soluções para Preservação de Órgãos , Preservação de Órgãos/métodos , Adolescente , Adulto , Idoso , Doença Hepática Terminal/cirurgia , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Reoperação , Estudos Retrospectivos , Fatores de Tempo , Isquemia Quente , Adulto Jovem
12.
Cancer Res ; 54(13): 3391-5, 1994 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8012956

RESUMO

The p53-inducible gene WAF1/CIP1 encodes a M(r) 21,000 protein (p21) that has been shown to arrest cell growth by inhibition of cyclin-dependent kinases. Induction of WAF1/CIP1 in cells undergoing p53-dependent G1 arrest or apoptosis supports the idea that WAF1/CIP1 is a critical downstream effector of p53. In the present study, we used embryonic fibroblasts from p53 "knock-out" mice to demonstrate p53-independent induction of WAF1/CIP1. We show that serum or individual growth factors such as platelet-derived growth factor, fibroblast growth factor, and epidermal growth factor but not insulin are able to induce WAF1/CIP1 in quiescent p53-deficient cells as well as in normal cells. The kinetics of this transient induction, which is enhanced by cycloheximide, demonstrates that WAF1/CIP1 is an immediate-early gene the transcript of which reaches a peak at approximately 2 h following serum or growth factor stimulation. On the other hand, DNA damage elicited by gamma-irradiation induces WAF1/CIP1 in normal human and mouse fibroblasts but does not affect WAF1/CIP1 expression in p53-deficient cells. These results suggest the existence of two separate pathways for the induction of WAF1/CIP1, a p53-dependent one activated by DNA damage and a p53-independent one activated by mitogens at the entry into the cell cycle. The possible function of p21 at this early stage is discussed.


Assuntos
Fase G1/genética , Regulação da Expressão Gênica/fisiologia , Genes Precoces/fisiologia , Genes Supressores de Tumor/fisiologia , Células 3T3 , Animais , Sequência de Bases , Cicloeximida/farmacologia , Genes Precoces/efeitos dos fármacos , Genes Precoces/efeitos da radiação , Genes Supressores de Tumor/efeitos dos fármacos , Genes Supressores de Tumor/efeitos da radiação , Genes p53/efeitos dos fármacos , Genes p53/fisiologia , Genes p53/efeitos da radiação , Substâncias de Crescimento/farmacologia , Insulina/farmacologia , Camundongos , Dados de Sequência Molecular , Fator de Crescimento Derivado de Plaquetas/farmacologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/deficiência
13.
Oncogene ; 9(10): 3021-4, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8084608

RESUMO

The recently discovered WAF1/CIP1 gene is a mediator of p53 tumor suppressor activity. To analyse WAF1/CIP1 for possible mutations, polymerase chain reaction (PCR) amplified cDNAs from several tumor cell lines were cloned and sequenced. A single point mutation which changes codon 31 from AGC to AGA (Ser to Arg) was found. This change resulted in the loss of a Bpu1102I and gain of an Esp3I restriction site, allowing for rapid screening of this mutation in human DNAs. Analysis of genomic DNAs from 50 randomly selected individuals revealed that this base pair substitution represents a polymorphism with an allelic frequency of 0.14. Transfection studies demonstrated that the expression of the Arg allele of WAF1/CIP1 was not associated with loss of tumor suppressor activity. Moreover, screening of 22 tumor DNA samples revealed no association between the tumor phenotype and the Arg allele of WAF1/CIP1 (two out of 22 tumor DNAs contained the Arg31 allele). This polymorphism will be a useful molecular marker in the analysis of loss of heterozygosity in human cancers, and further studies using a larger panel of tumors may reveal an association between this polymorphism and specific types of cancer.


Assuntos
Ciclinas/genética , Mutação Puntual , Polimorfismo Genético , Sequência de Aminoácidos , Arginina/genética , Sequência de Bases , Divisão Celular/genética , Células Cultivadas , Códon , Sequência Conservada , Inibidor de Quinase Dependente de Ciclina p21 , DNA , Genes p53 , Humanos , Dados de Sequência Molecular , Serina/genética
14.
Oncogene ; 11(4): 785-9, 1995 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-7544453

RESUMO

We have previously reported the tissue specific distribution of four different FGF-1 transcripts containing alternative 5' untranslated exons spliced to the first protein coding exon. The predominant transcript in brain is FGF-1.B and in kidney FGF-1.A. Others have shown, by in situ hybridization and immunohistochemical analysis, that expression of FGF-1 in the brain is exclusively in neural cells but not in glial cells. Here we have examined the distribution of FGF-1.B and FGF-1.A transcripts in glioblastoma and retinal tissues and in kidney carcinoma cell lines. Our results show that FGF-1.B is the predominant transcript in neural derived tissues including both the diabetic retina and normal retina tissues. Surprisingly, FGF-1.B transcript is highly expressed in glioblastoma tissues. In contrast, a normal brain glial cell line, CHII, expresses very low levels of FGF-1 mRNA. These results strongly implicate the role of FGF-1 in the etiology of glioblastoma. We also examined several kidney carcinoma derived cell lines for the expression of FGF-1 mRNA. Most of these kidney cell lines do not express any FGF-1 transcripts. An interpretation by deduction is that kidney adenocarcinomas are derived from cortex but medulla has been reported as the site of FGF-1 synthesis. Of the kidney derived cell lines which are positive for FGF-1 message, only one expressed FGF-1.A transcript. The data may suggest that the establishment of kidney cell lines results in a switch of promoter usage from the 1.A seen in kidney tissue. Similarly, culturing of glioma cell lines may result in a switch from FGF-1.B seen in glioma tissues to FGF-1.D seen in most glioma cell lines. Continued studies of the FGF-1 transcripts, their functional promoters and their tissues distribution will provide insight into the potential role of FGF-1 in cell growth, tissue differentiation and malignant transformation.


Assuntos
Neoplasias Encefálicas/metabolismo , Encéfalo/metabolismo , Fator 1 de Crescimento de Fibroblastos/biossíntese , Expressão Gênica , Glioblastoma/metabolismo , Neoplasias Renais/metabolismo , Neurônios/metabolismo , Transcrição Gênica , Processamento Alternativo , Northern Blotting , Linhagem Celular , Éxons , Expressão Gênica/efeitos dos fármacos , Humanos , RNA Mensageiro/biossíntese , Valores de Referência , Acetato de Tetradecanoilforbol/farmacologia , Células Tumorais Cultivadas
15.
Oncogene ; 15(7): 817-26, 1997 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-9266968

RESUMO

To assess the effect(s) of the C-terminal domain on FGFR2 function, we engineered a series of mutant FGFR2 cDNAs encoding deletions in the C-terminus of the receptor and compared their growth properties in NIH3T3 fibroblasts. In contrast to FGFR2-WT, receptors with C-terminal truncations induced ligand-independent transformation of NIH3T3 cells and transfectants expressing these mutant receptors efficiently formed colonies in semisolid medium. Introduction of point mutations (Y to F) into the C-terminus of FGFR2 at positions 813, 784 or 780 revealed that these mutant receptors also displayed activities similar to that of C-terminally truncated receptors. C-terminally altered FGF receptors did not show an increase in the basal level of receptor phosphorylation compared to that of FGFR2-WT suggesting that elevated receptor phosphorylation does not underlie the transforming activity of these receptors. Interestingly, expression of transforming FGFR2 derivatives, unlike H-Ras transformed cells, did not result in the activation of the mitogen-activated protein kinases (MAPKs), p42/ERK2 and p44/ERK1, indicating that this pathway is not constitutively active in FGFR2-transformed cells. Finally, we report the overexpression of FGFR2 mRNA and protein in several human tumor cell lines suggesting activation of the receptor in these tumors.


Assuntos
Proteínas Quinases Ativadas por Mitógeno , Fragmentos de Peptídeos/fisiologia , Receptores Proteína Tirosina Quinases/fisiologia , Receptores de Fatores de Crescimento de Fibroblastos/fisiologia , Tirosina/fisiologia , Células 3T3 , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Ensaio de Unidades Formadoras de Colônias , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno , Proteína Quinase 3 Ativada por Mitógeno , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fosforilação , Mutação Puntual , Proteínas Tirosina Quinases/metabolismo , RNA Mensageiro/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Receptores de Fatores de Crescimento de Fibroblastos/genética , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Deleção de Sequência , Transfecção , Células Tumorais Cultivadas , Tirosina/genética
16.
Oncogene ; 8(5): 1329-33, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8479752

RESUMO

By ectopic expression of cDNAs derived from a Ewing sarcoma cell line in NIH3T3 cells, we isolated a transforming gene (est). Sequence analysis revealed homology to the cot oncogene, which encodes a novel serine kinase. Whereas the cot product was truncated at its carboxy-terminal end as a result of gene rearrangement during transfection, est encodes the normal cot product. Thus, this gene can be activated as an oncogene by overexpression as well as by gene rearrangement. NIH3T3 cells transfected with est formed progressively growing colonies in soft agar and were tumorigenic in nude mice. The 3.2-kb est transcript was expressed at low level in both human fibroblasts and epithelial cells. Addition of the tumor promoter, okadaic acid (OA), or cytokine, interleukin 1 (IL-1), but not serum or platelet-derived growth factor (PDGF), induced increased expression of the est transcript. Using fluorescence in situ hybridization, we localized the est gene to the short arm of human chromosome 10 at band p11.2.


Assuntos
Clonagem Molecular , DNA/genética , Oncogenes , Proteínas Serina-Treonina Quinases/genética , Sarcoma de Ewing/genética , Células 3T3 , Sequência de Aminoácidos , Animais , Linhagem Celular , Mapeamento Cromossômico , Cromossomos Humanos Par 10 , DNA/isolamento & purificação , Regulação da Expressão Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Proto-Oncogenes , Homologia de Sequência do Ácido Nucleico , Células Tumorais Cultivadas
17.
Oncogene ; 12(5): 1097-107, 1996 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-8649802

RESUMO

DNA probes and antibodies specific for different coding regions of human SOS1 and GRF genes were used to screen expression of these genes in a variety of adult and fetal human tissues and cell lines. Despite previous reports of the exclusive expression of hGRF RNA in brain, we also observed expression of this gene in various other tissues including lung and pancreas, as well as several tumor cell lines. At least three different hGRF mRNA transcripts were observed depending on the probe used, with the larger transcripts being detected by probes corresponding to the 5' end of the gene while smaller transcripts were detected by probes corresponding to the 3' end. Expression of hSOS1-related transcripts was more ubiquitous and homogeneous than with hGRF, with similar levels of specific transcripts being detected in most tissues and cell fines tested. Three to five different transcripts were detected in human tissues when using probes for the 5' end and middle regions of this gene, whereas only two were detected with probes corresponding to the 3' end. Screening of multiple human tumor cell lines showed ubiquitous expression of three specific transcripts, although the level and ratio of each of these transcripts varied widely among individual cell lines. Consistent with the variety of transcripts detected, several protein forms were also identified in Western immunoblots with antisera raised against specific domains of hSOS1 and human Ras-GRF gene products. Fluorescence in situ chromosomal hybridization suggested that, in both cases, the multiple forms arise from single chromosomal loci. The heterogeneity of hGRF and hSOS1 gene products detected (which appear to retain in most cases a functional catalytic domain), suggests that differentially expressed, alternatively spliced hSOS1 and hGRF forms may contribute to fine regulation of Ras activation in different tissues or at different stages of development.


Assuntos
Proteínas Fúngicas/metabolismo , Proteínas/metabolismo , RNA/metabolismo , Proteínas Repressoras/metabolismo , Células 3T3/metabolismo , Adulto , Processamento Alternativo , Animais , Northern Blotting , Encéfalo/metabolismo , Linhagem Celular , Feto , Proteínas Fúngicas/genética , Regulação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina , Humanos , Hibridização In Situ , Rim/metabolismo , Pulmão/metabolismo , Camundongos , Pâncreas/metabolismo , Proteínas/genética , Proteínas Repressoras/genética , Proteína SOS1 , Células Tumorais Cultivadas , Fatores ras de Troca de Nucleotídeo Guanina , ras-GRF1
18.
Oncogene ; 9(10): 3017-20, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8084607

RESUMO

The recent discovery that expression of Waf1 (p21), an inhibitor of cyclin-dependent kinases, is induced by the tumor suppressor p53 provides an important linkage between growth suppression and the cell cycle. We report here the cloning and sequencing of a mouse p21 cDNA that contains the entire coding region. Hybridization of the mouse p21 probe in Southern blot analyses confirms that p21 is a single-copy gene and that the corresponding locus, Waf1, lies proximal to H-2 on mouse chromosome 17. In northern analyses, the expression of p21 is found in most normal mouse tissues, but a surprising lack of correlation is found between mRNA levels of p21 and p53. In order to determine which regions of p21 are most evolutionarily conserved, we have compared the cDNA sequences for the entire p21 coding region in 13 different mouse strains or species and the human p21 sequence. We conclude that two regions (corresponding to human codons 21-60 and 130-164) are strongly conserved in p21 and that these regions may represent domains that are especially critical to a functional p21 protein.


Assuntos
Mapeamento Cromossômico , Ciclinas/genética , Inibidores de Proteínas Quinases , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Inibidor de Quinase Dependente de Ciclina p21 , DNA , Humanos , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
19.
Clin Cancer Res ; 7(12): 3857-61, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11751475

RESUMO

PURPOSE: Arachidonate release contributes to prostate tumor progression as arachidonate is metabolized into prostaglandins and leukotrienes, potent mediators of immune suppression, cellular proliferation, tumor motility, and invasion. The group IIa sPLA2 (sPLA2-IIa) can facilitate arachidonate release from cellular phospholipids. We therefore sought to determine whether sPLA2-IIa expression might be related to the development or progression of prostatic adenocarcinoma (CaP). EXPERIMENTAL DESIGN: sPLA2-IIa expression was examined by Western blot analyses of CaP cells and xenografts and by immunohistochemistry of benign prostatic hyperplasias and primary human CaPs (n = 101) using a sPLA2-IIa-specific polyclonal antibody. RESULTS: sPLA2-IIa expression was increased dramatically in the androgen-independent CWR-22R and LNAI CaP cells versus the androgen-dependent CWR-22 and LNCaP cells. Immunohistochemical analyses revealed that sPLA2-IIa expression was also significantly increased with CaP development and advancing disease (trend analysis; Pearson correlation coefficient, P = 0.016). High-grade CaPs showed intense, uniform staining for sPLA2-IIa that was significantly different from that in adjacent benign prostatic hyperplasias (Fisher's exact test, P = 0.021) or low-grade CaP (P = 0.013), both of which showed only focal or weak sPLA2-IIa staining. Further, uniform sPLA2-IIa expression was directly related to the increased proliferative index that typifies advancing disease (P = 0.001). Most significantly, enhanced sPLA2-IIa expression was inversely related to 5-year patient survival (P = 0.015). CONCLUSIONS: These data show that sPLA2-IIa expression increases with progression to androgen-independence and is highest in the most poorly-differentiated, highest-grade primary human CaP samples.


Assuntos
Fosfolipases A/metabolismo , Neoplasias da Próstata/enzimologia , Androgênios/farmacologia , Ácido Araquidônico/metabolismo , Divisão Celular , Progressão da Doença , Humanos , Imuno-Histoquímica , Isoenzimas/metabolismo , Masculino , Fosfolipases A2 , Hiperplasia Prostática/enzimologia , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Transplante Heterólogo , Células Tumorais Cultivadas
20.
Endocrinology ; 137(6): 2232-7, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8641170

RESUMO

The participation of growth factors in wound healing and tissue repair has been well established. Previous studies demonstrated that the expression of keratinocyte growth factor (KGF) was greatly elevated shortly after injury and that topical application of KGF accelerated healing. Steroidal antiinflammatory agents, specifically glucocorticoids, markedly impair wound healing. The participation of KGF in wound healing led us to examine the effect of glucocorticoids on KGF production. The addition of dexamethasone significantly reduced the level of constitutively produced KGF messenger RNA, protein, and bioactivity in conditioned medium from dermal fibroblasts. This inhibitory effect was observed with a variety of glucocorticoids, whereas nonsteroidal antiinflammatory compounds had little effect on KGF synthesis. The mechanisms by which dexamethasone decreased KGF production include a combination of a diminished transcriptional rate and destabilization of the KGF messenger RNA. Cytokines such as interleukin-1 alpha, platelet-derived growth factor-BB, and transforming growth factor-alpha, typically up-regulated during wound healing, augment KGF expression by dermal fibroblasts. We determined that dexamethasone also blocked this inductive effect. These results suggest that glucocorticoids could inhibit KGF production in the setting of wound repair, which may contribute to the impairment of healing associated with glucocorticoid use.


Assuntos
Fatores de Crescimento de Fibroblastos , Glucocorticoides/farmacologia , Substâncias de Crescimento/biossíntese , Pele/efeitos dos fármacos , Pele/metabolismo , Animais , Becaplermina , Células Cultivadas , Dexametasona/farmacologia , Fator 10 de Crescimento de Fibroblastos , Fator 7 de Crescimento de Fibroblastos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Expressão Gênica/efeitos dos fármacos , Substâncias de Crescimento/genética , Humanos , Hidrocortisona/farmacologia , Interleucina-1/farmacologia , Cinética , Camundongos , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Proto-Oncogênicas c-sis , RNA Mensageiro/metabolismo , Fator de Crescimento Transformador alfa/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA