Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Pathologe ; 42(2): 235-240, 2021 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-33205311

RESUMO

In order to regulate their phosphate uptake, patients with end-stage renal disease rely on phosphate binders such as lanthanum carbonate (LC). The earliest histopathological reports of this rare entity in the gastrointestinal mucosa were described and published in 2015.We present a case of an 80-year-old patient with LC gastro-enteropathy. Histopathologically it can mimic other drug-induced depositions and even infectious or neoplastic entities. Evaluation of the patient's medical and especially drug history is essential to obtain the appropriate diagnosis. We present an overview of the clinical presentation and histological differential diagnosis of LC.


Assuntos
Falência Renal Crônica , Trato Gastrointestinal Superior , Idoso de 80 Anos ou mais , Mucosa Gástrica , Trato Gastrointestinal , Humanos , Lantânio , Estômago
2.
Nat Med ; 3(4): 447-50, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9095180

RESUMO

Breast cancers are either primarily resistant to chemotherapy (intrinsic resistance), or respond to chemotherapy but later recur with a multidrug-resistant phenotype because of overexpression of the multidrug transporter P-glycoprotein. The MDR1 gene encoding P-glycoprotein may be transcriptionally regulated by a Y-box transcription factor. We now report that, in multidrug-resistant MCF-7 breast cancer cells, nuclear localization of YB-1 is associated with MDR-1 gene expression. In drug-sensitive MCF-7 cells, however, YB-1 was localized to the cytoplasm. Regulated overexpression of YB-1 in drug-sensitive diploid breast epithelial cells induced MDR-1 gene expression and multidrug resistance. In 27 out of 27 untreated primary breast cancers, YB-1 protein was expressed in the cytoplasm although it was undetectable in normal breast tissue of these patients. In a subgroup of tumors (9/27), however, YB-1 was also localized to the nucleus and, in these cases, high levels of P-glycoprotein were present. These results show that in a subset of untreated primary breast cancers, nuclear localization of YB-1 protein is associated with intrinsic multidrug resistance. Our data show that YB-1 has an important role in controlling MDR1 gene transcription and this finding provides a basis for the analysis of molecular mechanisms responsible for intrinsic multidrug resistance in human breast cancer.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Neoplasias da Mama/genética , Proteínas Estimuladoras de Ligação a CCAAT , Proteínas de Ligação a DNA/metabolismo , Resistência a Múltiplos Medicamentos/genética , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição/metabolismo , Adulto , Idoso , Neoplasias da Mama/patologia , Compartimento Celular , Núcleo Celular/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Transcrição NFI , Proteínas Nucleares , Transcrição Gênica , Proteína 1 de Ligação a Y-Box
3.
J Exp Med ; 183(3): 1205-13, 1996 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8642262

RESUMO

The transcription factor E2F is regulated during the cell cycle through interactions with the product of the retinoblastoma susceptibility gene and related proteins. It is thought that E2F-mediated gene regulation at the G1/S boundary and during S phase may be one of the rate-limiting steps in cell proliferation. It was reported that in vivo overexpression of E2F-1 in fibroblasts induces S phase entry and leads to apoptosis. This observation suggests that E2F plays a role in both cell cycle regulation and apoptosis. To further understand the role of E2F in cell cycle progression, cell death, and tumor development, we have blocked endogenous E2F activity in HBL-100 cells, derived from nonmalignant human breast epithelium, using dominant-negative mutants under the control of a tetracycline-dependent expression system. We have shown here that induction of dominant-negative mutants led to strong downregulation of transiently transfected E2F-dependent chloramphenicol acetyl transferase reporter constructs and of endogenous c-myc, which has been described as a target gene of the transcription factor E2F/DP. In addition, we have shown that blocking of E2F could efficiently protect from apoptosis induced by serum starvation within a period of 10 d, whereas control cells started to die after 24 h. Surprisingly, blocking of E2F did not alter the rate of proliferation or of DNA synthesis of these cells; this finding indicates that cell-cycle progression could be driven in an E2F-independent manner. In addition, we have been able to show that blocking of endogenous E2F in HBL-100 cells led to rapid induction of tumor growth in severe combined immunodeficiency mice. No tumor growth could be observed in mice that received mock-transfected clones or tetracycline to block expression of the E2F mutant constructs in vivo. Thus, it appears that E2F has a potential tumor-suppressive function under certain circumstances. Furthermore, we provide evidence that dysregulation of apoptosis may be an important step in tumorigenesis.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas de Transporte , Proteínas de Ciclo Celular , Ciclo Celular , Proteínas de Ligação a DNA , Regulação da Expressão Gênica , Genes myc , Fatores de Transcrição/metabolismo , Animais , Apoptose , Sequência de Bases , Divisão Celular , Linhagem Celular , Cloranfenicol O-Acetiltransferase/biossíntese , Primers do DNA , Replicação do DNA , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Feminino , Fibroblastos , Genes Dominantes , Humanos , Cinética , Camundongos , Dados de Sequência Molecular , Transplante de Neoplasias , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/biossíntese , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Proteínas Recombinantes/biossíntese , Proteína 1 de Ligação ao Retinoblastoma , Fator de Transcrição DP1 , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/biossíntese , Transfecção
4.
Top Curr Chem ; 288: 1-15, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-22328025

RESUMO

Glycosylation of proteins, lipids and mucins has gained increasing complexity in the course of evolution. Metazoans and mammals exhibit extensively exploited pathways of N-glycan biosynthesis, with unique features that are not found in plants or protozoans.Paralleling the complexity of N-glycan structure, their impact on regulatory processes has become very diverse and has evolved into a multidimensional lattice imprinting modes of cellular communication. Processes that are regulated by N-glycans are cellular adhesion and motility, growth factor and cytokine signalling, metabolic homeostasis, and binding of certain pathogens. Consequently, alterations in N-glycan biosynthesis interfere with cellular proliferation and differentiation and may produce disturbances in embryonic development, trigger inflammatory processes, favour tumour development and enhance the metastastic dissemination of primary tumours. Particular N-glycans that have been causally related to these pathological scenarios are the complex-type N-glycans, branching from oligomannosidic core structures into ß-glycosidic linkages, connected to acetylated glucosamine and galactose, and yield extended lactosamine chains of variable length. These N-acetyllactosamines are preferred building blocks for further modification by fucosylation, sialylation, and sulphation, thus creating binding sites for different galectins or selectins. The focus of this review will be on the b1,6-N -acetylglucosaminyltransferase-V/GnT-V/MGAT5, a phylogenically conserved enzyme that is required for the synthesis of ß1,6-branched complex-type oligosaccharides in the medial Golgi compartment, and its implications in metabolism and cancer progression.

5.
Oncogene ; 26(19): 2747-58, 2007 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-17057731

RESUMO

CEACAM1, also known as biliary glycoprotein (BGP), CD66a, pp120 and C-CAM1, is a member of the CEA immunoglobulin superfamily. CEACAM1 is a putative tumor suppressor based on diminished expression in some solid neoplasms such as colorectal carcinoma. However, CEACAM1 is overexpressed in some tumors such as non-small cell lung cancer. To clarify the mechanism of action of this cell adhesion molecule, we studied thyroid carcinoma that has a spectrum of morphologies and variable behavior allowing separation of proliferation from invasion and metastasis. CEACAM1 is expressed in thyroid carcinoma cell lines derived from tumors that exhibit aggressive behavior. Introduction of CEACAM1 into endogenously deficient WRO cells resulted in reduced cell cycle progression associated with p21 upregulation and diminished Rb phosphorylation. Forced CEACAM1 expression enhanced cell-matrix adhesion and migration and promoted tumor invasiveness. Conversely, small interfering RNA (siRNA)-mediated downregulation of CEACAM1 expression in MRO cells accelerated cell cycle progression and significantly enhanced tumor size in xenografted mice. CEACAM1 is not appreciably expressed in normal thyroid tissue or benign thyroid tumors. In a human thyroid tissue array, CEACAM1 reactivity was associated with metastatic spread but not with increased tumor size. These findings identify CEACAM1 as a unique mediator that restricts tumor growth whereas increasing metastatic potential. Our data highlight a complex repertoire of actions providing a putative mechanism underlying the spectrum of biologic behaviors associated with thyroid cancer.


Assuntos
Antígenos CD/fisiologia , Antígeno Carcinoembrionário/metabolismo , Moléculas de Adesão Celular/fisiologia , Proliferação de Células , Neoplasias da Glândula Tireoide/patologia , Adenocarcinoma Folicular/metabolismo , Adenocarcinoma Folicular/patologia , Adulto , Idoso , Animais , Antígeno Carcinoembrionário/genética , Carcinoma/metabolismo , Carcinoma/patologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Masculino , Camundongos , Camundongos SCID , Pessoa de Meia-Idade , Invasividade Neoplásica , RNA Interferente Pequeno/farmacologia , Neoplasias da Glândula Tireoide/metabolismo
7.
J Clin Invest ; 97(11): 2651-9, 1996 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-8647960

RESUMO

We have studied the expression of members of the bcl-2 family in human breast cancer. The expression pattern of these genes in breast cancer tissue samples was compared with the expression pattern in normal breast epithelium. No marked difference with regard to bcl-2 and bcl-xL expression was observed between normal breast epithelium and cancer tissue. In contrast, bax-alpha, a splice variant of bax, which promotes apoptosis, is expressed in high amounts in normal breast epithelium, whereas only weak or no expression could be detected in 39 out of 40 cancer tissue samples examined so far. Of interest, downregulation of bax-alpha was found in different histological subtypes. Furthermore, we transfected bax-alpha into breast cancer cell lines under the control of a tetracycline-dependent expression system. We were able to demonstrate for the first time that induction of bax expression in breast cancer cell lines restores sensitivity towards both serum starvation and APO-I/Fas-triggered apoptosis and significantly reduces tumor growth in SCID mice. Therefore, we propose that dysregulation of apoptosis might contribute to the pathogenesis of breast cancer at least in part due to an imbalance between members of the bcl-2 gene family.


Assuntos
Apoptose , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas Proto-Oncogênicas/biossíntese , Animais , Sequência de Bases , Mama/metabolismo , Divisão Celular , Linhagem Celular , Primers do DNA , DNA de Neoplasias/biossíntese , Epitélio/metabolismo , Feminino , Humanos , Camundongos , Camundongos SCID , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-bcl-2 , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Proteínas Recombinantes/biossíntese , Valores de Referência , Transcrição Gênica , Transfecção , Células Tumorais Cultivadas , Proteína X Associada a bcl-2 , Receptor fas/fisiologia
8.
J Natl Cancer Inst ; 67(3): 539-47, 1981 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6944526

RESUMO

In 50 patients with gastrointestinal carcinomas, the following tumor parameters were studied: the concentration and localization of carcinoembryonic antigen (CEA) in tissue, extension, invasion, infiltration, differentiation, and necrosis. CEA concentrations were measured in plasma samples of all patients. In 7 patients with gastric carcinomas, CEA concentrations in tissue were low. Generally, only single cells or cell groups were CEA-positive. Elevated CEA levels in plasma resulted mainly from distant metastases and not from the primary tumor. In 43 colorectal carcinomas, CEA concentrations in tissue varied between 1.5 and 472 microgram/g tissue. They were closely related to the degree of accumulation of CEA-positive necrotic material in the degree of accumulation of CEA-positive necrotic material in the neoplastic glands. In 35 patients with colorectal carcinomas without CEA producing distant metastases, preoperative CEA levels in plasma were normal when tumor necrosis and perineural invasion were absent and CEA concentrations in tissue were low. CEA levels in plasma were regularly elevated when the tumor showed considerable necrosis in the presence of high CEA concentrations in tissue.


Assuntos
Antígeno Carcinoembrionário/metabolismo , Carcinoma/imunologia , Neoplasias Gastrointestinais/imunologia , Neoplasias Gastrointestinais/sangue , Neoplasias Gastrointestinais/patologia , Neoplasias Gastrointestinais/cirurgia , Humanos , Necrose , Metástase Neoplásica
9.
Cancer Res ; 57(12): 2354-7, 1997 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9192807

RESUMO

Among the members of the carcinoembryonic antigen (CEA) family, CD66a (human C-CAM) and CGM2 (CEA gene family member 2) mRNAs are frequently down-regulated in colorectal cancer. In contrast, nonspecific cross-reactive antigen (NCA) mRNA is overexpressed in the majority of these carcinomas. In animal models, the rodent homologues of CD66a have been shown to act as tumor suppressors, suggesting an important role in carcinogenesis. Here we investigate the mRNAs of CD66a, CGM2, and NCA in 22 human colorectal adenomas and the respective normal mucosa specimens by Northern blots. The expression of both CD66a and CGM2 changed in a concomitant fashion. Using oligonucleotides specific for the N-terminal domains, two CD66a transcripts 3.9 and 1.5 kb in size were identified. These showed a greater than 50% down-regulation in 20 of 22 and 18 of 22 adenomas, respectively. Reduction of the CGM2 message was observed in 21 of 22 cases. Complete or near-complete losses of the CD66a 3.9-kb mRNA and the CGM2 message were found in 13 of 22 and 15 of 22 of the tumors, respectively. The medians of CD66a and CGM2 expressions were between 0.3 and 0.0, respectively. The tumor:normal ratio of NCA mRNA expression was increased up to 2.4-fold in 11 of 22 adenomas. Altogether, these results compare well to the changes reported previously for colorectal carcinomas. The high frequency and early appearance of dysregulation of members of the carcinoembryonic antigen family during colorectal tumorigenesis suggests that these changes may be important for the development of the malignant phenotype.


Assuntos
Adenoma/metabolismo , Antígenos CD/metabolismo , Antígenos de Diferenciação/metabolismo , Neoplasias Colorretais/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/metabolismo , Northern Blotting , Antígeno Carcinoembrionário , Moléculas de Adesão Celular/metabolismo , Feminino , Proteínas Ligadas por GPI , Humanos , Mucosa Intestinal/metabolismo , Queratinas/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo
10.
Cancer Res ; 55(14): 2963-7, 1995 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-7606710

RESUMO

The localization of biliary glycoprotein (BGP) and its mRNA in normal colonic mucosa was studied by immunohistochemistry and in situ hybridization. BGP mRNA was confined to columnar epithelial cells and expressed abundantly in the superficial mature cells and at low levels in differentiating cells in the upper crypts. Epithelial expression of BGP coincided with that of BGP mRNA. Ultrastructurally, BGP was localized to microfilaments of the fuzzy coat of the columnar cells at the luminal surface and the upper crypts. Additionally, BGP was found in cryptal caveolated cells. The results are consistent with primary transcriptional regulation of BGP production and suggest that BGP synthesis is controlled by the degree of cytodifferentiation. The fuzzy-coat localization of BGP implies a role in nonspecific defense mechanisms against pathogens.


Assuntos
Colo/metabolismo , Glicoproteínas/biossíntese , Mucosa Intestinal/metabolismo , RNA Mensageiro/metabolismo , Adulto , Anticorpos Monoclonais , Especificidade de Anticorpos , Antígenos CD , Moléculas de Adesão Celular , Neoplasias do Colo/induzido quimicamente , Glicoproteínas/genética , Humanos , Imuno-Histoquímica , Hibridização In Situ , Microscopia Eletrônica , Sondas RNA , RNA Mensageiro/genética , Sensibilidade e Especificidade
11.
Cancer Res ; 52(8): 2329-39, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1559235

RESUMO

The binding specificities of 52 well-characterized monoclonal antibodies (Mabs) against carcinoembryonic antigen (CEA) from 12 different research groups were studied by immunohistochemistry and immuno flow cytometry. In addition, the binding constant for the interaction between Mab and CEA was determined by a solution-phase assay. Cryostat sections of colon carcinoma and normal colon, stomach, liver, pancreas, and spleen were studied by immunohistochemistry. Peripheral blood granulocytes, monocytes, and lymphocytes were assayed by immuno flow cytometry. The Mabs used here have previously been classified into five essentially nonoverlapping epitope groups (GOLD 1-5) (Cancer Res., 49: 4852-4858, 1989). Most Mabs cross-reacted with different normal tissues, ranging from highly cross-reactive Mabs (positive reaction with 8 of 9 discriminating tissues) to relatively specific Mabs (positive reaction with 1 of 9 discriminating tissues). Five Mabs (10%) were specific, reacting only with colon carcinoma, normal colon mucosa, and normal gastric foveola. There was a correlation between epitope group and binding specificity. Mabs with a high degree of CEA specificity almost exclusively belonged to epitope groups 1, 2, and 3, while highly cross-reactive Mabs belonged to epitope groups 4 and 5. There was no correlation between antibody specificity and affinity for CEA. Specific Mabs with high as well as low affinity were found.


Assuntos
Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Antígeno Carcinoembrionário/imunologia , Adulto , Idoso , Colo/imunologia , Neoplasias do Colo/imunologia , Reações Cruzadas/imunologia , Feminino , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Masculino
12.
Oncogene ; 11(8): 1649-55, 1995 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-7478590

RESUMO

CD66a, also known as 'biliary glycoprotein (BGP)', is the human homologue of a cell adhesion molecule (CAM) of the rat (Cell-CAM). CD66a, which belongs to the carcinoembryonic antigen family and the immunoglobulin superfamily, is expressed in cells of myeloid and epithelial origin. The cytoplasmic domain of the major isoform of CD66a (CD66acyt) contains two tyrosine residues in amino acid motifs potentially interacting with protein tyrosine kinases of the Src family. Here we provide evidence that CD66a is associated with pp60c-src. From membrane fractions of granulocytes and the colonic cell line HT29, phosphokinase activity was co-immunoprecipitated with CD66a when monoclonal CD66 antibodies or an antiserum against the recombinant cytoplasmic domain of CD66a were used. From the dissociated immunecomplexes, a phosphokinase of M(r) 60,000 was reprecipitated using antibodies against pp60c-src. In vitro, the recombinant cytoplasmic domain was a substrate and binding partner of pp60c-src. Phosphopeptides corresponding to the tyrosine containing amino acid sequences of CD66acyt activated the kinase activity of pp60c-src to a greater extent than a phosphopeptide containing Tyr527 from the SH2-binding regulatory domain of pp60c-src. The down-regulation of CD66a in about 80% of colorectal carcinomas may contribute to a dysregulation of pp60c-src in colorectal cancer.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação/metabolismo , Moléculas de Adesão Celular/metabolismo , Glicoproteínas/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Sequência de Aminoácidos , Antígeno Carcinoembrionário/genética , Carcinoma/metabolismo , Células Cultivadas , Neoplasias Colorretais/metabolismo , Regulação para Baixo , Ativação Enzimática , Granulócitos/citologia , Humanos , Dados de Sequência Molecular , Família Multigênica , Fosfopeptídeos/química , Fosfopeptídeos/metabolismo , Fosforilação , Fosfotirosina/metabolismo , Testes de Precipitina , Transdução de Sinais , Domínios de Homologia de src
13.
Oncogene ; 17(5): 611-23, 1998 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-9704927

RESUMO

The E2F family of transcription factors are essential for the regulation of genes required for appropriate progression through the cell cycle. Five members of the E2F family have been previously reported, namely E2F1-5. All five are key elements in transcriptional regulation of essential genes, and they can be divided into two functional groups, those that induce S-phase progression when overexpressed in quiescent cells (E2Fs 1-3), and those that do not (E2Fs 4-5). Here, we describe the identification of a novel member of this family, which we refer to as E2F-6. E2F-6 shares significant homology with E2Fs 1-5, especially within the DNA binding, heterodimerization and marked box domains. Unlike E2Fs 1-5, E2F-6 lacks a transactivation and a pocket protein binding domain, hence, forms a unique third group within the E2F family. E2F-6 is a nuclear protein that can form heterodimers with the DP proteins (both DP-I and DP-2) in vitro and in vivo. Our results show that the complex formed between E2F-6 and the DP proteins, possesses high DNA binding activity, displaying a preference for a TTTCCCGC E2F recognition site, which is slightly different to the E2F consensus site derived from the E2 promoter (TTTCGCGC). In contrast to the other members of the E2F family, ectopic expression of E2F-6 inhibits transcription from promoters possessing E2F recognition sites rather than activating transcription. In addition, overexpression of E2F-6 suppresses the transactivational effects of coexpression of E2F-1 and DP-1. The inhibitory effect of E2F-6 is dependent on its DNA binding activity and its ability to form heterodimers with the DPs. Interestingly, ectopic expression of E2F-6 leads to accumulation of cells in S-phase. Our data suggest that E2F-6 expression delays the exit from S-phase rather than inducing S-phase, which further emphasizes the functional difference between E2F-6 and the previously known E2F family members.


Assuntos
Proteínas de Ciclo Celular , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Ciclo Celular , DNA Complementar , Proteínas de Ligação a DNA/genética , Fator de Transcrição E2F6 , Expressão Gênica , Células HL-60 , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/genética , Coelhos , Proteínas Repressoras/genética , Homologia de Sequência de Aminoácidos , Distribuição Tecidual , Fator de Transcrição DP1 , Fatores de Transcrição/genética , Células Tumorais Cultivadas
14.
J Clin Oncol ; 12(4): 725-9, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7512130

RESUMO

PURPOSE: To establish a sensitive assay for the specific detection of carcinoembryonic antigen (CEA)-expressing tumor cells in the bone marrow of patients with colorectal cancer and other CEA-positive carcinomas. PATIENTS AND METHODS: A CEA-specific nested reverse transcriptase (RT) polymerase chain reaction (PCR) assay was developed and optimized using limiting dilutions of a CEA-positive cancer cell line mixed with normal bone marrow cell specimens. The optimized test was then used to examine bone marrow samples obtained from 15 patients with abdominal carcinomas (colorectal, n = 10; pancreatic, n = 3; gastric, n = 2) and six patients with breast cancer. Specificity was assessed by examination of 56 negative controls (malignant hematologic disease, n = 28; nonmalignant disease conditions, n = 5; healthy bone marrow donors, n = 8; normal peripheral-blood samples, n = 15). For 11 patients with abdominal carcinomas, immunostaining evaluations were performed using an anti-CEA and an anticytokeratin antibody, and the results compared with the nested PCR assay. RESULTS: In the sensitivity calibration system, single CEA-expressing tumor cells were detected in 2 to 5 x 10(7) normal bone marrow cells. All 56 control samples failed to amplify. This demonstrates that mRNAs coding for highly homologous CEA-related antigens expressed by various lineages of blood cells do not interfere. Bone marrow samples from 10 of 15 patients with abdominal cancers and four of six breast cancer patients scored positive, indicating micrometastatic bone disease. Four of 11 samples from the gastrointestinal cancer patients were found to be positive by the PCR method, but were negative with the immunocytology method. CONCLUSION: Since approximately 30% of the colorectal carcinoma patients that score negative in immunocytology staining of bone marrow samples have been reported to relapse, earlier diagnosis of the presence of malignant cells is needed. Our result that samples scoring positive in the described CEA-specific PCR test remained negative by two immunostaining methods suggests a higher sensitivity. We conclude that PCR amplification of CEA mRNA may lead to an earlier diagnosis of micrometastatic bone disease in patients with CEA-expressing carcinomas.


Assuntos
Medula Óssea/imunologia , Antígeno Carcinoembrionário/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Sequência de Bases , Doenças da Medula Óssea/diagnóstico , Antígeno Carcinoembrionário/metabolismo , Feminino , Expressão Gênica , Humanos , Masculino , Dados de Sequência Molecular , Metástase Neoplásica/diagnóstico , DNA Polimerase Dirigida por RNA , Sensibilidade e Especificidade
15.
J Mol Med (Berl) ; 75(10): 728-44, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9382997

RESUMO

Nucleic acid technology has assumed an essential role in various areas of in vitro diagnosis. Its major applications include the genomic characterization of mutations and polymorphisms, amplification of nucleic acids by the polymerase chain reaction, analysis of gene expression patterns at the mRNA level, specific detection of mutant proteins, and engineering of proteins used in ligand binding assay. Manipulating the expression of genes in cells and experimental animals allows detailed analysis of processes leading from genomic alterations to disease manifestations and may ultimately yield refinements in diagnostic strategies. The addition of DNA and RNA to the conventional diagnostic in vitro targets and novel approaches to the study of disease processes and manifestations characterize a diagnostic strategy referred to as "molecular diagnostics." This contribution describes some of essential ways in which molecular diagnostics differs from conventional diagnostic approaches. Applications such as differential diagnosis, prenatal diagnosis, early diagnosis, and diagnosis of disease susceptibility are well established in single-gene disorders, and the diagnostic impact of DNA polymorphisms is steadily increasing in multifactorial diseases. The high sensitivity of the polymerase chain reaction makes possible the detection of single infectious agents or tumor cells. With increasing knowledge of expressed gene sequences the expression pattern of mRNA will reflect the biological state of cells with high precision. Mutant proteins can be analyzed based on their structural or biological properties. Use of the appropriate expression systems makes it possible to design proteins for diagnostic in vitro applications such as ligand binding assays.


Assuntos
Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Envelhecimento/genética , Animais , DNA/análise , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/genética , Técnicas Genéticas , Genética Médica , Humanos , Mutação , Neoplasias/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , RNA/análise
16.
Mol Immunol ; 22(11): 1273-7, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2417110

RESUMO

Antigens related to the carcinoembryonic antigen (CEA) were isolated from normal human plasma by perchloric acid extraction, gel permeation chromatography and immunoaffinity chromatography using a monoclonal antibody with broad specificity and high affinity. The antigens were separated by SDS-polyacrylamide gel electrophoresis and transferred to nitrocellulose. The binding of five monoclonal anti-CEA antibodies with different epitope specificities to the immobilized antigens was analyzed. Two antigens with mol. wts of greater than 200,000 and 177,000 bound all five antibodies, and two antigens with mol. wts of 114,000 and 85,000 bound three of the five antibodies. The findings reported indicate that even monoclonal antibodies with high specificity for colonic cancer CEA detect CEA-related antigens in normal human plasma.


Assuntos
Antígeno Carcinoembrionário/análise , Anticorpos Monoclonais/imunologia , Antígenos/análise , Antígeno Carcinoembrionário/imunologia , Antígeno Carcinoembrionário/isolamento & purificação , Cromatografia de Afinidade , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Epitopos/imunologia , Humanos
17.
J Invest Dermatol ; 106(1): 64-9, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8592083

RESUMO

The carcinoembryonic antigen (CEA) family comprises a group of glycoproteins including the classical CEA, nonspecific cross-reacting antigens (NCA), and biliary glycoprotein (BGP). CEA glycoproteins have been identified in many glandular and mucosal tissues. In view of their putative role in cell adhesion, protein sorting, and signal transduction, CEA glycoproteins are thought to be involved in embryogenesis, architectual integrity, and secretory mechanisms of glandular epithelia. Since there are few data available on the expression of CEA-like proteins in human skin, the aim of this study was to immunohistochemically specify and localize the CEA glycoproteins in cutaneous adult and fetal glands using a panel of well-characterized antibodies. The secretory parts of eccrine sweat glands expressed CEA, NCA-90, and BGP, whereas apocrine glands remained unreactive for CEA glycoproteins. The ductal epithelia of both eccrine and apocrine glands contained CEA and NCA-90. Sebaceous glands were stained for BGP only. Electron microscopy of sweat glands showed CEA glycoprotein expression in cytoplasmic organelles and on microvilli lining the ductal surface. In sebaceous glands, BGP were demonstrated in small vesicles and along the cell membranes of differentiating sebocytes. Fetal development of cutaneous glands was associated with early expression of CEA glycoproteins. Additionally, mice transgenic for human CEA were shown to express CEA in sweat glands. The overall distribution of CEA glycoproteins in cutaneous glands was consistent with that in epithelia of other glandular tissues.


Assuntos
Envelhecimento/metabolismo , Antígeno Carcinoembrionário/química , Glicoproteínas/fisiologia , Glândulas Sebáceas/química , Pele/química , Glândulas Sudoríparas/química , Adulto , Animais , Feto/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Glândulas Sebáceas/ultraestrutura , Pele/embriologia , Pele/ultraestrutura , Glândulas Sudoríparas/ultraestrutura
18.
Gene ; 159(1): 43-7, 1995 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-7541767

RESUMO

Micrometastases of solid tumors are most commonly detected by immunocytochemistry using monoclonal antibodies directed against tissue-specific gene products like cytokeratin-18 (CK-18) and the carcinoembryonic antigen (CEA). While CK-18 is a marker for epithelia in general, CEA is mainly employed in the detection of gastrointestinal and breast carcinomas. To improve the sensitivity and specificity of micrometastasis detection, we planned to establish polymerase chain reaction (PCR) assays for both markers. Here we provide strong evidence for the existence of a CK-18 pseudogene, since specific amplification (i) was readily obtained from healthy bone marrow donors, (ii) did not require reverse transcription of CK-18 mRNA and (iii) was not abolished by RNase treatment. Using a CK-18-specific probe, Southern blot analyses revealed identical-size fragments for both genomic DNA and a CK-18 cDNA after digestion with appropriate restriction enzymes. On the other hand, the amplification of CEA mRNA (i) was never observed in bone marrow samples of healthy donors or patients without solid tumors, (ii) required intact mRNA and the reverse transcriptase reaction, and (iii) could not be obtained after RNase treatment. In reconstitution experiments, single CEA-expressing tumor cells were reliably detected among 2 x 10(7) normal bone marrow cells. We conclude that, due to the presence of pseudogene(s), PCR-based detection systems are not readily suitable for CK-18, while the CEA mRNA amplification should provide a sensitive and specific test for the presence of ectopic, and hence presumed malignant, CEA-expressing cells in body fluids.


Assuntos
Antígeno Carcinoembrionário/genética , Queratinas/genética , Metástase Neoplásica/diagnóstico , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Sequência de Bases , Medula Óssea/química , DNA/análise , DNA Complementar/análise , Amplificação de Genes , Humanos , Dados de Sequência Molecular , Metástase Neoplásica/genética , Pseudogenes/genética , RNA Mensageiro/análise , RNA Mensageiro/sangue , Mapeamento por Restrição , Sensibilidade e Especificidade , Transcrição Gênica
19.
FEBS Lett ; 261(2): 405-9, 1990 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-2178978

RESUMO

Immobilized carcinoembryonic antigen (CEA) and non-specific crossreacting antigen (NCA) bound 3 strains of E. coli of human origin. The binding was dose dependent, saturable, and of high avidity. Binding of the bacteria to CEA and NCA was completely abolished in the presence of 10 mM alpha-methyl D-mannopyranoside. Bacteria did not bind to concanavalin A. In addition, binding to deglycosylated CEA was either absent or significantly reduced. These findings indicate that the E. coli strains bind to D-mannosyl residues in CEA and NCA. Considering the tissue distribution of CEA (brush border of colonic epithelium) and NCA (granulocytes), these glycoproteins may be involved in the recognition of bacteria.


Assuntos
Antígenos de Neoplasias , Antígeno Carcinoembrionário/metabolismo , Moléculas de Adesão Celular , Escherichia coli/metabolismo , Glicoproteínas/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Fezes/microbiologia , Glicosilação , Testes de Hemaglutinação , Humanos , Técnicas Imunoenzimáticas , Manose/metabolismo , Metilmanosídeos/farmacologia , Traqueia/microbiologia
20.
Eur J Cancer ; 36(17): 2240-3, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11072212

RESUMO

In 1962, a programme for early detection of cervical cancer was established at the national level. The programme is based on the collaboration of different groups of doctors and not on a system of sending out invitations to every woman. This programme was re-adapted twice according to the needs for assuring quality in a system of mainly liberal medicine. At present the programme is 'institutionalised' and is carried out according to the criteria defined in 1990. This includes a centralisation of the smear readings and handing out the material needed to take the smears. The contribution of the doctors is regulated by a system of bonuses given by the government and a reimbursement by the Health Fund. The annual cervical smear is free of charge for every woman. The participation of the women targeted by the programme (>15 years old) has increased by approximately 50% every decade from the early 1970s increasing from 10950 in 1972 to 70441 in 1999. Between 1980 and 1999, the number of women at risk taking part in the programme increased from 10.80 to 38.92%. The number of all the doctors taking smear samples increased from 68 to 105 and the number of gynaecologists increased from 19 (ratio Gyn/GP (gynaecologists/General Practitioners) of 28%) to 52 (ratio Gyn/GP of 50%). The mortality rate has decreased continuously from 6. 1/100000 in 1990 to 0.9/100000 in 1997. In conclusion, to be successful, a cervical cancer screening programme should be flexible enough to allow short-term adaptations to unexpected local situations and needs a highly motivated team of the different participants involved in the regional and national health policy.


Assuntos
Programas de Rastreamento/organização & administração , Neoplasias do Colo do Útero/prevenção & controle , Coleta de Dados/métodos , Feminino , Pessoal de Saúde , Humanos , Luxemburgo , Programas de Rastreamento/normas , Avaliação de Programas e Projetos de Saúde , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA