RESUMEN
Hyaluronan (HA) is a glycosaminoglycan constituent of extracellular matrix. In its native form HA exists as a high molecular weight polymer, but during inflammation lower molecular weight fragments accumulate. We have identified a collection of inflammatory genes induced in macrophages by HA fragments but not by high molecular weight HA. These include several members of the chemokine gene family: macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta, cytokine responsive gene-2, monocyte chemoattractant protein-1, and regulated on activation, normal T cell expressed and secreted. HA fragments as small as hexamers are capable of inducing expression of these genes in a mouse alveolar macrophage cell line, and monoclonal antibody to the HA receptor CD44 completely blocks binding of fluorescein-labeled HA to these cells and significantly inhibits HA-induced gene expression. We also investigated the ability of HA fragments to induce chemokine gene expression in human alveolar macrophages from patients with idiopathic pulmonary fibrosis and found that interleukin-8 mRNA is markedly induced. These data support the hypothesis that HA fragments generated during inflammation induce the expression of macrophage genes which are important in the development and maintenance of the inflammatory response.
Asunto(s)
Quimiocina CCL2/genética , Regulación de la Expresión Génica/inmunología , Ácido Hialurónico/inmunología , Proteínas Inflamatorias de Macrófagos/genética , Macrófagos Alveolares/inmunología , Monocinas/genética , Animales , Anticuerpos Bloqueadores/inmunología , Anticuerpos Monoclonales/inmunología , Northern Blotting , Lavado Broncoalveolar , Células Cultivadas , Quimiocina CCL4 , Quimiocina CCL5/genética , Quimiocina CXCL10 , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Humanos , Receptores de Hialuranos/inmunología , Inflamación/genética , Interleucina-8/genética , Ratones , Fibrosis Pulmonar/genética , Fibrosis Pulmonar/inmunología , ARN Mensajero/análisis , ARN Mensajero/biosíntesisRESUMEN
In vivo and in vitro studies have linked small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) cells along a differentiation continuum. The transition of a SCLC toward a NSCLC phenotype is modeled in culture by the simultaneous overexpression of myc and ras genes in cultured SCLC cells. A major phenotypic distinction between SCLC and NSCLC in culture is that SCLC cells usually grow in floating aggregates, whereas NSCLC cells and myc- plus ras-expressing SCLC cells grow as adherent spreading monolayers like other epithelial cells. The present studies examine how myc, ras, cell aggregation, and attachment to laminin may interact to modulate transitions between the SCLC and NSCLC phenotypes. We find that myc-expressing SCLC cells, which normally grow as anchorage-independent cells in plastic flasks, will adhere to laminin and exhibit an epithelial morphology. In this setting, the cells express both NSCLC and SCLC markers, thus resembling a tumor type previously termed NSCLC with neuroendocrine features. Anchorage-dependent SCLC cells simultaneously expressing the myc family and an exogenous ras oncogene move further toward the NSCLC phenotype than the above myc-expressing cells. However, forced suspension of such cells restores the expression of neuroendocrine SCLC features. These studies indicate that cell environment, as much as gene expression events, profoundly affects aspects of the SCLC cell phenotype.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Células Pequeñas/patología , Genes myc/genética , Genes ras/genética , Neoplasias Pulmonares/patología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Biomarcadores , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Células Pequeñas/metabolismo , Adhesión Celular , Agregación Celular , Proteínas de Unión al ADN/genética , Epitelio , Regulación Neoplásica de la Expresión Génica , Humanos , Hidrogeles , Laminina , Neoplasias Pulmonares/metabolismo , Sistemas Neurosecretores , Fenotipo , Polihidroxietil Metacrilato/análogos & derivados , Proteína Quinasa C/genética , Proteína Quinasa C beta , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Factores de Transcripción/genética , Factor de Crecimiento Transformador beta/genética , Células Tumorales CultivadasRESUMEN
PURPOSE: Malignant pleural mesothelioma is a rare malignancy with major environmental implications regarding passive asbestos exposure. We have conducted an immunohistochemical and functional study to address three questions: (1) What is the representation of CD44 on tumor cells as detected by immunohistochemistry? (2) Do cultured cell lines derived from malignant pleural mesothelioma tissue express the same CD44 phenotypes as the original tumors, and can they serve as a model for the study of CD44 in mesotheliomas? (3) What is the functional status of the CD44 expressed on mesotheliomas, with regard to hyaluronan anchorage? MATERIALS AND METHODS: Thirty-seven samples of pleural mesothelioma were obtained from patients entered on phase I/II protocols conducted in the Surgery Branch of the National Cancer Institute since 1991. The diagnosis was confirmed in all 37 patients by means of a battery of immunohistochemical tests for markers differentiating malignant pleural mesothelioma from adenocarcinoma. Tumor-positive lymph nodes and distant metastases were also examined in six of the patients. Cell lines, established from tumor tissue of six of the patients described above, were used in these experiments. Four (H2596, H2461, H2373, H2452) were derived from primary solid tumors and two (HP-1 and HP-3) were derived from effusions. RESULTS: Immunohistochemical staining with a monoclonal antibody (H4C4) that recognizes a constant region of human CD44 demonstrated that 34 (92%) of the malignant pleural mesotheliomas examined expressed CD44 on 50% to 100% of their cells. The extent of CD44 expression was apparently related to histologic subtype with the highest expression seen in epithelioid mesotheliomas and the least in sarcomatoid tumors. Tumor cell lines established from the primary tumors or effusions of six of the malignant pleural mesothelioma patients showed high expression of the hematopoietic form of CD44. Four of these cell lines exhibited strong attachment to hyaluronan in an in vitro attachment assay, indicating that their CD44 was functional with respect to hyaluronan anchorage. Hyaluronan attachment was specific in that it could be abolished by preincubation with epitope-specific anti-CD44 antibodies or soluble substrate or by hyaluronidase treatment of attachment surfaces. CONCLUSIONS: We conclude that CD44 is highly expressed on human mesotheliomas, that cell lines adequately represent tumor expression, and that CD44 mediates association with hyaluronan, a major component of pleural fluid.
Asunto(s)
Receptores de Hialuranos/biosíntesis , Ácido Hialurónico/metabolismo , Mesotelioma/metabolismo , Neoplasias Pleurales/metabolismo , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Western Blotting , Adhesión Celular/fisiología , Línea Celular Tumoral , Humanos , Receptores de Hialuranos/inmunología , Inmunohistoquímica , Mesotelioma/inmunología , Mesotelioma/patología , Neoplasias Pleurales/inmunología , Neoplasias Pleurales/patologíaRESUMEN
We report the sequence and genomic organization of a gene linked to Ki-ras in the mouse and coamplified in Y1 murine adrenal carcinoma cells. The entire 4.4-kb cDNA sequence as well as promoter and splice sites for each of the three exons was determined. The gene, designated KRAG (Ki-ras-associated gene) has a CG-rich first exon and promoter region and a long 3' untranslated region and encodes 216 amino acids. The putative 23.9-kDa protein has four potential transmembrane hydrophobic domains. The hydropathy plot resembles that of certain tumor-associated antigens, including CO-029 and ME491. A potential human homologue, EST05985, was identified and provisionally mapped to human chromosome 12, a chromosome syntenic to mouse chromosome 6, the previously mapped location of KRAG.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Proteínas Portadoras , Genes ras , Ligamiento Genético , Proteínas de la Membrana/genética , Proteínas de Neoplasias , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN , Proteínas de la Membrana/química , Ratones , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Células Tumorales CultivadasRESUMEN
CD44 is an integral membrane glycoprotein that functions as a receptor for the extracellular matrix glycan, hyaluronan. Here we report that CD44 is a novel biomarker for non-small cell lung tumors, squamous metaplasia of the lung, and activated type II pneumocytes. We have examined the expression of CD44 in 12 human lung tumor cell lines and 23 fixed, paraffin-embedded lung cancers. CD44 transcription and translation is consistently high among non-small cell tumors (5 of 5 cell lines, 10 of 14 tumors) but rare in small cell tumors (1 of 6 cell lines, 0 of 9 tumors). In normal lung, CD44 was confined to the surface of bronchial basal cells and alveolar macrophages. Squamous metaplasia of the lung showed strong CD44 immunoreactivity. Resting type II pneumocytes were largely CD44 negative but rows of active, surfactant-secreting type II cells had significant amounts of CD44 located on lateral surfaces of adjacent cells. The correlation between CD44 and the non-small cell phenotype was further demonstrated in studies of a cultured small cell lung cancer line induced to exhibit characteristics of a non-small lung cancer by infection with v-Ha-ras. Following ras gen insertion, these cells showed a 40-fold increase in CD44 expression. The CD44 detected in lung cancer cells throughout these studies was predominantly the "standard" rather than the "variant" species. Taken together, these results suggest that CD44 is a protein expressed on non-small cell lung tumors, squamous metaplasia, and activated type II cells. In addition, CD44 in cultured small cell lung cancer cells is transcriptionally activated following differentiation by the ras oncogene. The fact that immunohistochemistry can be used to discriminate among the cell types makes CD44 a valuable new marker for lung neoplasia.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/fisiopatología , Carcinoma de Células Pequeñas/fisiopatología , Proteínas Portadoras/fisiología , Neoplasias Pulmonares/fisiopatología , Receptores de Superficie Celular/fisiología , Receptores Mensajeros de Linfocitos/fisiología , Antígenos de Superficie/fisiología , Secuencia de Bases , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Bronquios/patología , Bronquios/fisiología , Carcinoma de Pulmón de Células no Pequeñas/química , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Células Pequeñas/genética , Proteínas Portadoras/genética , Epitelio/fisiología , Genes ras/genética , Humanos , Receptores de Hialuranos , Pulmón/fisiología , Neoplasias Pulmonares/química , Neoplasias Pulmonares/genética , Metaplasia/genética , Datos de Secuencia Molecular , Fenotipo , Empalme del ARN/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Superficie Celular/genética , Receptores Mensajeros de Linfocitos/genética , Transducción Genética/genética , Células Tumorales CultivadasRESUMEN
We have investigated the mechanism by which LAMP-1, a principal protein of the lysosomal membrane, is targeted to lysosomes. Mutagenesis and transfection experiments indicate that the motif Tyr-X-X-hydrophobic residue at the carboxyl terminus of the 11-amino acid cytoplasmic tail of the protein constitutes the lysosomal targeting signal for LAMP-1. This motif directs CD44, a cell surface hyaluronate receptor, to the lysosomal membrane, but only when the signal is placed at the carboxyl-terminus of a truncated cytoplasmic tail. The signal did not confer lysosomal targeting when it was situated internally or at the carboxyl terminus of the normal CD44 cytoplasmic tail. An apparent paradox is that similar Tyr-containing sequences mediate internalization, but not lysosomal targeting, of several receptors. Of possible relevance is the additional finding that purified LAMP-1 protein lacks the two carboxyl-terminal residues predicted by cDNA, both of which are essential for proper trafficking. A model is proposed in which lysosomal targeting is distinguished from receptor internalization through proteolytic modification of the internalization signal.
Asunto(s)
Antígenos CD , Lisosomas/metabolismo , Glicoproteínas de Membrana/química , Señales de Clasificación de Proteína/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Citoplasma/metabolismo , ADN/genética , Humanos , Membranas Intracelulares/metabolismo , Proteínas de Membrana de los Lisosomas , Lisosomas/ultraestructura , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Ratones , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Señales de Clasificación de Proteína/metabolismo , Receptores Mensajeros de Linfocitos/química , Receptores Mensajeros de Linfocitos/genética , Receptores Mensajeros de Linfocitos/metabolismo , Transfección , Tripsina/metabolismoRESUMEN
Reliable discriminatory tests to predict metastatic disease would clearly facilitate the management of cancer in the elderly. We have recently identified a 90-110-kilodalton (kDa) cell surface glycoprotein that is differentially expressed in benign and malignant murine adrenal carcinoma cells. In view of the proteins highly glycosylated nature, we have tested its ability to bind to a panel of agarose-bound lectins. Wheat germ agglutinin (WGA), a lectin specific for terminal sialic acid and N-acetylglucosamine (G1cNAc), had a strong affinity for the metastasis-related protein but failed to detect such a glycoprotein in nonmetastatic cells. Treatment of cells with sialidase to remove terminal sialic acids did not affect the affinity of the protein for the lectin, indicating the presence of terminal G1cNAc. We show by in situ that this metastatic binding protein (MBP) is regionally concentrated on the surface of invasive cells but absent in cells unable to invade. We postulate that MBP plays an active role in cell migration through interactions with beta-1,4 galactosytransferase and basement membrane glycoproteines.
Asunto(s)
Glicoproteínas de Membrana/análisis , Metástasis de la Neoplasia , Proteínas de Neoplasias/análisis , Acetilglucosamina/metabolismo , Neoplasias de las Glándulas Suprarrenales , Animales , Carcinoma , Galactosa/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones , Proteínas de Neoplasias/metabolismo , Neuraminidasa/farmacología , Células Tumorales Cultivadas , Aglutininas del Germen de Trigo/metabolismoRESUMEN
Many previous studies have implicated cell surface saccharides, and sialylglycoconjugates in particular, as important mediators of tumor cell metastasis. In this report, we have used three different specific sialidases and a highly sensitive high-performance liquid chromatographic sialic acid assay to probe the cell surfaces of several murine adrenal carcinoma variants. In contrast to several earlier studies on other metastatic variants, we find no significant differences in the overall levels of cell surface or total cellular sialic acid among three Y1 murine adrenal carcinoma variants with widely different metastatic phenotypes. However, using highly purified, linkage-specific sialyltransferases, in conjunction with V. cholerae sialidase, to probe the cell surface saccharide topography of specific penultimate oligosaccharides, we do find striking differences in oligosaccharide structures underlying the sialic acid moieties. Two tumorigenic and metastatic variants (F2 and F4) contain about 6-fold more penultimate Gal beta 1----4GlcNAc sialylation sites than a related tumorigenic but nonmetastatic variant (HSR) when CMP-[3H]-N-acetylneuraminic acid and the Gal beta 1----4GlcNAc alpha 2,6 sialyltransferase are used to probe the adrenal carcinoma cell surfaces. The metastatic variants also are found to contain 4- to 4.5-fold more Gal beta 1----3GalNAc sialylation sites than the nonmetastatic variant when the Gal beta 1----3GalNAc alpha 2,3 sialyltransferase is used as a cell surface probe. Earlier work, which used the same sialyltransferase probes on sialidase-treated murine melanoma variants (A. Passaniti and G. W. Hart, J. Biol. Chem., 263: 7591-7603, 1988), also showed similar quantitative differences in penultimate structures between metastatic variants. However, in contrast to the adrenal carcinoma cells, the highly metastatic melanoma cells have severalfold lower levels of sialylatable penultimate Gal beta 1----4GlcNAc and Gal beta 1----3GalNAc saccharides compared to their nonmetastatic counterparts. Thus, while the precise structural alterations or surface accessibilities of penultimate saccharides appear to be cell type dependent, these results suggest that pronounced changes in penultimate cell surface sialo-oligosaccharide moieties occur during progression to a malignant phenotype in two widely different tumor systems. These types of alterations in the underlying penultimate oligosaccharide structures of cell surface sialoglycoconjugates may be a common feature of highly metastatic cells arising from very different tumor cell types.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/química , Glicoproteínas/análisis , Proteínas de Neoplasias/análisis , Oligosacáridos/análisis , Ácidos Siálicos/análisis , Acetilgalactosamina/análisis , Acetilglucosamina/análisis , Neoplasias de las Glándulas Suprarrenales/patología , Animales , Cromatografía Líquida de Alta Presión , Metástasis de la Neoplasia , Neuraminidasa , Conformación Proteica , Células Tumorales CultivadasRESUMEN
Using the Matrigel invasion assay, we have examined the role of cell adhesion and migration in the invasiveness of two cell lines, DM and HSR, derived from the Y1 mouse adrenocortical tumor. The DM cells were metastatic and more invasive (10-fold) than the nonmetastatic HSR cells. The difference in invasiveness could not be ascribed to different levels of secreted type IV collagenolytic activity since HSR cells secreted higher levels of activity. Cells from the metastatic DM line showed greater motility to both laminin and fibronectin when compared to the HSR line. Furthermore, both Matrigel and laminin promoted the attachment and spreading of DM cells but they had little effect on the adhesion of the HSR cells. Electron microscopic examination revealed an increased ruffling of the cell membrane in the metastatic DM line. These studies suggest a role for cell adhesion and migration on the invasion of Matrigel by malignant tumor cells.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/patología , Carcinoma/patología , Adhesión Celular/fisiología , Movimiento Celular/fisiología , Animales , Colágeno/metabolismo , Ratones , Invasividad Neoplásica , Metástasis de la Neoplasia , Células Tumorales CultivadasRESUMEN
We have examined the role of a cell surface galactosyltransferase, laminin, and laminin-binding protein (receptor) in the invasion of clonal derivatives of a murine adrenal carcinoma cell line. Although a 10-fold variation was found in the ability to invade a reconstituted basement membrane matrix, levels of intracellular laminin and the laminin-binding protein were shown to be present and secreted equally in all lines. Of the eight lines tested, seven showed a correlation between invasion and the incorporation of [3H]galactose from UDP-[3H]galactose into a 90- to 110-kDa protein. One noninvasive line (clone HSR), however, retained high galactosyltransferase activity yet could not galactosylate the endogenous 90- to 110-kDa substrate. Interestingly, this clone was unable to attach to laminin. Although high galactosyltransferase activity can be consistent with cells of high invasiveness, our results suggest that the galactosylation status of a 90- to 110-kDa Y1 cell surface glycoprotein is most indicative of invasion potential.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/enzimología , Galactosiltransferasas/metabolismo , Glicoproteínas/metabolismo , Invasividad Neoplásica , Proteínas de Neoplasias/metabolismo , Neoplasias de las Glándulas Suprarrenales/patología , Animales , Línea Celular , Membrana Celular/enzimología , Células Cultivadas , Células Clonales , Galactosa/metabolismo , Galactosiltransferasas/genética , Glicosilación , Immunoblotting , Cinética , Laminina/análisis , Ratones , Peso Molecular , ARN Mensajero/genética , Receptores Inmunológicos/análisis , Receptores de LamininaRESUMEN
Our goal was to compare and contrast in the same normal twins the relative contribution of genetic and environmental factors to large interindividual variations in the metabolism of acetaminophen (APAP) and antipyrine. These drugs were selected because they are biotransformed by different mechanisms. A single oral dose of APAP (10 mg/kg) was given to six sets of monozygotic (MZ) and six sets of dizygotic (DZ) twins. All were normal, nonsmoking, nonmedicated, and male. Among these 24 subjects, there were 300% interindividual variations in rate constants for formation of the sulfate and glucuronide conjugates, as well as in the overall rate constant for APAP elimination. Intratwin variations for each measurement were as large within MZ as within DZ twinships, suggesting that predominantly environmental rather than genetic factors maintained interindividual variations. Two other observations support this conclusion: Intraindividual variations were frequently as large as interindividual variations, and regardless of zygosity for twins living together, intratwin correlation coefficients were almost twice those of twins living apart. Quite different results were obtained when these twins received antipyrine. After a single oral dose of antipyrine (18 mg/kg), 500% interindividual variations in rate constants for formation of the three main oxidative metabolites of antipyrine appeared to be mainly under genetic control. Also for antipyrine and its principal metabolites, intraindividual variations were much smaller than interindividual variations. In contrast to the results with APAP, regardless of zygosity, intratwin correlation coefficients for antipyrine were similar for twins living apart and twins living together. This comparison between APAP and antipyrine metabolism in the same carefully selected normal twins under apparently uniform environmental conditions reveals that interindividual variations in APAP metabolism arise from certain unidentified environmental factors, whereas genetic factors cause the large interindividual variations that occur in antipyrine disposition.
Asunto(s)
Acetaminofén/metabolismo , Antipirina/metabolismo , Gemelos Dicigóticos , Gemelos Monocigóticos , Gemelos , Acetaminofén/análogos & derivados , Acetaminofén/orina , Administración Oral , Adolescente , Adulto , Antipirina/análogos & derivados , Antipirina/orina , Biotransformación , Cromatografía Líquida de Alta Presión , Ambiente , Femenino , Semivida , Humanos , Cinética , Masculino , EmbarazoRESUMEN
Mechanisms for large variations in rates of elimination of the model compound antipyrine (AP) were investigated by administering AP to 144 normal, uninduced subjects (83 unrelated adults and 61 members of 13 families). Urine was collected at regular intervals for 72 h and concentrations of AP and its three main metabolites were measured. Rate constants for formation of each AP metabolite were calculated. When values for each AP rate constant were plotted arithmetically for 83 unrelated subjects, trimodal curves emerged. Probit plots of these values showed inflections at the two antimodes of each trimodal distribution. Members of all 13 families were assigned a phenotype determined by where their AP metabolite rate constant placed them in the trimodal distributions derived from unrelated subjects. In each family, pedigree analysis to test a Mendelian hypothesis for transmission of these three phenotypes was consistent with their monogenic control for each AP metabolite. The same two-step procedure used here for AP offers a general approach for identifying other polymorphisms of drug oxidation. This method consists of constructing distribution curves for unrelated subjects, which allow the phenotypes of families to be determined so that segregation patterns can then be traced.
Asunto(s)
Antipirina/metabolismo , Hígado/metabolismo , Polimorfismo Genético , Adolescente , Adulto , Antipirina/orina , Femenino , Heterocigoto , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Linaje , Saliva/análisisRESUMEN
The advantages and limitations of the 2 most commonly used methods to investigate interindividual pharmacokinetic variations are reviewed. The first method is based on pharmacokinetic comparisons made after repeated administration of a model drug such as antipyrine, before, during and after imposition of a carefully controlled environmental perturbation. A principal virtue of the test is the use of each subject as a control. Subjects are usually under near basal conditions with respect to factors capable of altering hepatic drug-metabolising capacity. Exceedingly sensitive, the test yields highly reproducible results. It has been useful as a research tool in identifying environmental factors for which dose-response curves can be generated and compared. However, the test requires careful selection and control of subjects, and it may be hazardous to extrapolate results to subjects under different, non-basal, environmental conditions. This method most frequently involves antipyrine as the test compound, but other drugs can and have been used. The results disclose that many host factors that influence antipyrine disposition also affect the disposition of other drugs metabolised by hepatic mixed-function oxidases. Recent refinement of the antipyrine test involves measurement of the rate constant for formation of each of the 3 main metabolites of antipyrine. Sensitivity and specificity of the test are increased through examination of the effect of each factor on a separate hepatic cytochrome P-450. Due to the labouriousness of this procedure and its requirement for several days of urine collection from each subject, metabolite analysis will probably remain an experimental method not applicable for screening populations. The second method involves a particular model based on multiple regression analysis. Relying on correlations with historical data of a qualitative nature, previous applications of this method have been retrospective, rather than prospective. Several such correlations could not be confirmed in normal subjects under the conditions of a controlled prospective experiment. Thus, prospective studies need to be performed to check results obtained with this method. The model used appears to enjoy certain advantages, including speed, simplicity, and ease of execution.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Preparaciones Farmacéuticas/metabolismo , Acetilación , Antipirina/metabolismo , Dicumarol/metabolismo , Femenino , Genética , Humanos , Individualidad , Cinética , Modelos Biológicos , Linaje , Fenilbutazona/metabolismo , Embarazo , Análisis de Regresión , GemelosRESUMEN
To investigate mechanisms that control large variations among normal uninduced subjects in the elimination of the model compound antipyrine (AP) and other drugs, AP was administered to 144 subjects (83 unrelated adults and 61 members of 13 families). Thereafter, at regular intervals for 72 h, the urine of each subject was collected and concentrations of AP and its three main metabolites measured. From these urinary concentrations, rate constants for formation of each AP metabolite were calculated. Trimodal curves were observed when values for each AP rate constant were plotted in 83 unrelated subjects; probit plots of these values showed inflections at the two antimodes of each trimodal distribution. All members of our 13 families were assigned one of three phenotypes determined by where their AP metabolite rate constant placed them in the trimodal distributions derived from the 83 unrelated subjects. In each family, pedigree analysis to identify the mode of transmission of these three phenotypes was consistent with their monogenic control. These results provide evidence for a new polymorphism of drug oxidation in man.
Asunto(s)
Antipirina/orina , Hígado/metabolismo , Polimorfismo Genético , Adolescente , Adulto , Antipirina/análogos & derivados , Genotipo , Humanos , Cinética , Persona de Mediana Edad , Linaje , Fenotipo , Estadística como AsuntoRESUMEN
Adult, male, unmedicated twins received antipyrine orally under carefully controlled environmental conditions. Relative contributions of genetic and environmental factors to 2-fold interindividual variations in rate constants for formation of the three main antipyrine metabolites were compared. Heritabilities for rate constants for formation of 4-hydroxyantipyrine, N-demethylantipyrine, and 3-hydroxymethylantipyrine were 0.88, 0.85, and 0.70, respectively. These results suggest that each molecular form of cytochrome P-450 that converts antipyrine to a different metabolite exhibits genetically controlled interindividual variations in activity. Unrelated adult male subjects whose environments were also carefully controlled exhibited highly reproducible rate constants for formation of antipyrine metabolites. Because the rate constant for metabolite formation sensitively detects certain variations in the gene product, it should be used in future pharmacogenetic studies on rates of production of multiple metabolites from a single parent drug.