Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Growth of choriocarcinoma cells in the presence of 5-bromo-2'-deoxyuridine (BrdUrd) results in a 30- to 40-fold increase in alkaline phosphatase activity. The effects of BrdUrd is specific for phosphatase with an alkaline pH optimum. The induction by BrdUrd is probably not due to the production of an altered enzyme, since the induced enzyme resembles the basal enzyme in thermal denaturation and kinetic properties. Enzyme induction can be prevented by thymidine but not by deoxycytidine or deoxyuridine. The induction of alkaline phosphatase appears to require incorporation of the BrdUrd into cellular DNA. The presence of BrdUrd in the growth medium is not necessary for alkaline phosphatase induction in proliferating cells containing BrdUrd-substituted genomes. However, enzyme induction and maintenance of the induced levels of alkaline phosphatase in nonproliferating cells containing BrdUrd-substituted DNA requires the presence of the analogues in the medium. The induction of alkaline phosphatase by BrdUrd in probably an indirect process.
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PMID:Induction of placental alkaline phosphatase in choriocarcinoma cells by 5-bromo-2'-deoxyuridine. 1

Alkaline phosphatase is induced in human choriocarcinoma cells by short-chain fatty acids, especially sodium butyrate. This fatty acid increases the phosphatase activity immediately and in a nearly linear fashion. Only phosphatase with an alkaline pH optimum is induced. Both the induced alkaline phosphatase and the basal enzyme are precipitated by antiserum against term-placental alkaline phosphatase, but the choriocarcinoma phosphatase is less stable to heating than is the term-placental enzyme. The induction of alkaline phosphatase activity requires cellular synthesis of protein, RNA and DNA. The regulation of induction probably occurs at the transcriptional level.
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PMID:Regulation of the induction of alkaline phosphatase in choriocarcinoma cells by sodium butyrate. 4 10

The coincident expression of two structurally distinct isoenzymes of human alkaline phosphatase was demonstrated in two independently derived gestational choriocarcinoma cell lines. These proteins were shown to have enzymatic, antigenic, and physical-chemical properties resembling those of isoenzymes from term placenta and adult liver. The regulation of these isoenzymes has been studied during the exposure of both cell lines to 5-bromodeoxyuridine and dibutyryl cyclic AMP. The responses of the alkaline phosphatase isoenzymes to these agents have also been compared with the response of another protein phenotypic to placenta, the alpha subunit of chorionic gonadotropin. The results show that (i) the separate structural genes coding for placental and liver alkaline phosphatases are regulated in a noncoordinate fashion; (ii) both alkaline phosphatase genes respond independently of the alpha subunit; and (iii) the induction of the placental type isoenzyme occurs via at least two independent pathways.
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PMID:Regulation of alkaline phosphatase expression in human choriocarcinoma cell lines. 21 97

The present work examined the expression of cell surface glycoprotein antigens in cultured human cell lines. The set of glycoproteins studied was defined by their immunoreactivity with antiserum developed to Triton-solubilized extracts of placental brush border membranes. Studies were performed using cell lines of trophoblastic (BeWo, JEG-3) and nontrophoblastic (Chang liver cells) origin, as well as diploid fibroblast cell lines (WI-38, GM-38). Antiplacental brush border antiserum reacts with at least 19 distinct antigens present in placental membrane preparations, each of which can be resolved and identified in two-dimensional electrophoresis. The subunit molecular weight and isoelectric point for all components were defined by their positions in the two-dimensional matrix. Thirteen of these could be detected among the five cell lines examined by lactoperoxidase-catalyzed cell surface iodination. One of these 13 antigens has been identified as the placental isoenzyme of alkaline phosphatase (PAP). The expression of this component is limited to choriocarcinoma cells and Chang liver cells and it is not present in diploid fibroblasts. Under normal circumstances expression of PAP is unique to the differentiated placenta but has been frequently demonstrated in both trophoblastic and nontrophoblastic neoplasms. Two other antigens are variably expressed among the different cell types examined in the present study and their presence or absence was independent of the trophoblastic, epithelial nontrophoblastic, or fibroblastic origin of the cells. Ten surface antigens were expressed in all five cell lines. Six of these had previously been found common to membranes from three adult differentiated tissues, including liver and kidney, as well as placenta (Wada et al, J Supramol Struc 10(3): 287-305, 1979). The presence of this set of antigens in cultured cells as well extends the possibility that these are ubiquitously expressed on human cell surfaces. Two other antigens observed in all cultured cells had been found in both placental and either kidney or liver membranes and may represent common functions shared by many tissues which are also necessary for growth in vitro. The two remaining placental antigens seen in all cultured cells have previously been shown to be absent in adult tissues. Their presence in cultured cells but not in the membranes of resting differentiated tissues may signify the expression of glycoproteins characteristic of trophoblasts in all cells adapted to growth in culture.
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PMID:Human placental cell surface antigens:expression by cultured cells of diverse phenotypic origin. 54 28

In this study we compare the specific activities and isoenzyme patterns of five enzymes--phosphoglucose isomerase, phosphoglucomutase, hexokinase, lactate dehydrogenase, and alkaline phosphatase--in term placenta with the analogous enzymes in a clone of choriocarcinoma cells grown in culture. Phosphoglucose isomerase, phosphoglucomutase, and lactate dehydrogenase specific activities of the choriocarcinoma did not differ by more than two or three times from the mean activities of the comparable enzymes in placenta; the specific activity of hexokinase in the choriocarcinoma amounted to 14 per cent of the mean value for placenta. In contrast, the mean specific activity of heat-stable alkaline phosphatase in the choriocarcinoma amounted to only 1 per cent of the mean value for placenta. By growing the cells in 5-bromodeoxyuridine, 20 mug per milliliter, we were able to increase alkaline phosphatase activity to 68 per cent of the mean value for placenta. For both extracts, phosphoglucose isomerase zymograms were similar and phosphoglucomutase zymograms were similar. The hexokinase zymogram of term placenta showed two isoenzymes which stained more intensely with 0.5 mM. glucose than with 0.1M glucose. A hexokinase isoenzyme was observed in zymograms of both extracts which stained more intensely with 0.1M glucose than with 0.5 mM glucose. Lactate dehydrogenase exhibited an extra isoenzyme in the choriocarcinoma extract. When the cells were cultivated in medium containing 5 mug per milliliter of 5-bromodeoxyuridine, the induced phosphatase in the cell line was electrophoretically similar to placental phosphatase. At higher concentrations of 5-bromodeoxyuridine, the most anodal isoenzyme was 0.5 cm. slower in mobility than the comparable placental isoenzyme.
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PMID:Enzymes of normal and malignant trophoblast: phosphoglucose isomerase, phosphoglucomutase, hexokinase, lactate dehydrogenase, and alkaline phosphatase. 111 69

During spontaneous or chemically induced differentiation human choriocarcinoma cells express typical characteristics of the normal differentiating trophoblast: 1) increased production of peptide and steroid hormones (chorionic gonadotropin, placental lactogen, estrogens, progesterone); 2) increased activity of cellular alkaline phosphatase; 3) morphological transition from cytotrophoblast to syncytiotrophoblast-like cells; and 4) arrested cell proliferation. Since the extracellular matrix is known to control gene expression we have examined the effects of different substrates composed of matrix macromolecules on the differentiation of BeWo choriocarcinoma cells. Matrices tested were: fibronectin, laminin, collagens type I and type IV, the basement membrane-like complex matrix Matrigel, and a complex matrix extracted from human term placenta. Irrespective of the type of molecule(s), it was consistently found that, whenever the matrix molecules were presented as three-dimensional structures (as opposed to protein coatings on tissue culture plastic) the response of affected differentiation markers monitored was highly pronounced. Morphology was changed from monolayers to rounded colonies, cell proliferation was reduced, and the secretion of chorionic gonadotropin was increased up to tenfold. Heterogeneous effects were observed on progesterone secretion and on the activity of cellular alkaline phosphatase. Cell adhesion to matrix molecules, however, did not depend on the structure of the matrix. This study demonstrates that gene expression in these tumor cells can be modified by extracellular matrix and highlights that not only the presence of effector molecules in the matrix but also the three-dimensional structure of the matrix is important for the induction of differentiation.
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PMID:Modulation of differentiation markers in human choriocarcinoma cells by extracellular matrix: on the role of a three-dimensional matrix structure. 145 63

The alkaline phosphatase (AP) synthesized by human tumor cells closely resembles human placental AP (PLAP). Little is known about the molecular events that lead to the expression of a placenta-like AP in tumor cells. The complementary DNA encoding the AP expressed by a choriocarcinoma cell line, BeWo, was isolated and characterized. The complementary DNA is the product of the germ cell AP (Nagao isozyme) gene and not of the term PLAP gene. Like placental AP, the tumor AP can be released from the cell membrane by a phosphaditylinositol-specific phospholipase C and has a phosphaditylinositol-glycan (PI-glycan) moiety at the COOH terminus. Immunoprecipitation of phosphaditylinositol-specific phospholipase C-treated AP and analysis by polyacrylamide gel electrophoresis or isoelectric focusing demonstrates that at least 95% of the AP contains PI-glycan. Two-dimensional gel electrophoresis reveals two precursors of the mature AP. One of these does not bind an antibody against the Trypanosoma variable surface glycoprotein cross-reacting determinant and probably does not contain PI-glycan. This precursor had a shorter half-life than the more prominent PI-glycan-containing precursor in pulse-chase experiments, suggesting a precursor-product relationship between the two proteins. These data demonstrate that BeWo AP is the product of a gene normally expressed in testis, thymus, and germ cells, but not in placenta. Thus, the expression of BeWo AP results from the repression of the PLAP gene and derepression of the germ cell AP gene and, as such, the expression is ectopic. The BeWo AP (Nagao isozyme) is modified with PI-glycan that is added soon after translation, not cotranslationally.
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PMID:Expression of a Nagao-type, phosphatidylinositol-glycan anchored alkaline phosphatase in human choriocarcinomas. 216 49

Electron microscopic observations showed that the fungal metabolite brefeldin A caused disassembly of the Golgi complex in human choriocarcinoma cells and accumulation of alkaline phosphatase (ALP) in the endoplasmic reticulum (ER) and nuclear envelope, where ALP was not apparently detectable in control cells. Pulse/chase experiments with [35S]methionine demonstrated that in the control cells, ALP synthesized as a 63-kDa precursor form was rapidly converted to a 66-kDa form, by processing of its N-linked oligosaccharides from the high-mannose type to the complex type, which was expressed on the cell surface after 30 min of chase. In contrast, in the brefeldin-A-treated cells the precursor was gradually converted to a 65-kDa form, slightly smaller than the control mature form, which was not expressed on the cell surface even after a prolonged time of chase. Kinetics of the ALP processing in the brefeldin-A-treated cells demonstrated that the precursor was initially converted to an intermediate form, partially sensitive to endo-beta-N-acetylglucosaminidase H (endo H), then to an endo-H-resistant 65-kDa form. In addition, this form was found to be sensitive to neuraminidase digestion, though its sialylation was not so complete as that of the control mature form. Taken together, these results suggest that under disassembly of the Golgi complex caused by brefeldin A, oligosaccharide-processing enzymes including sialyltransferase, an enzyme in the trans Golgi cisterna(e) and/or the trans Golgi network, might be redistributed into the ER and involved in processing of the oligosaccharides of ALP accumulating there.
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PMID:Intracellular accumulation and oligosaccharide processing of alkaline phosphatase under disassembly of the Golgi complex caused by brefeldin A. 226 2

A continuous in vitro cell line of rat choriocarcinoma has been established. It is composed of pure trophoblast cells which multiply and differentiate. The morphology of the cells is very similar to normal rat cytotrophoblasts and giant cells. The cultured cells contain cytokeratin, alkaline phosphatase and express the receptors for Bandeira simplificifolia Agglutinin-I (BSA-I). They are hormonally active as demonstrated by the presence of lactogen and progesterone in the supernatant of the culture. The injected cells develop into choriocarcinoma in syngeneic as well as allogeneic rats. The morphological, biological and immunohistochemical features of these tumors are identical to those described in the transplantable neoplasm from which the in vitro line was established. The presence of Y chromosome in cultured cells proves the paternal origin of the primary tumor developed from extra-embryonic membranes in fetectomized rat and makes this neoplasm similar to human post-gestation choriocarcinoma.
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PMID:Establishment and characterization of a continuous in vitro line from a rat choriocarcinoma. 232 51

Clinical and laboratory studies have confirmed the efficacy of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCH) as tumor markers in the diagnosis, monitoring and assessment of prognosis in cases of testicular tumor. Serum AFP level is positive in 75% of yolk sac tumors, 70% of embryonal carcinomas and 62% of teratomas. All cases of choriocarcinoma show elevated serum hCG. In the treatment of prostatic cancer, prostatic acid phosphatase (PAP), prostatic-specific antigen (PA) and gamma-seminoprotein (gamma-Sm) are important serum markers, and the RIA method has improved their specificity and sensitivity. These markers are also correlated well with therapeutic efficacy. Especially, improvement of the serum PAP level in patients with stage C and D cancer indicates prolongation of survival time. Over 90% of the metastatic lesions of prostatic cancer are encountered in the skeletal system. Thus, serum alkaline phosphatase and urinary hydroxyproline are considered to be useful markers for indicating bone involvement. In other urological malignancies, there are no specific tumor markers. As non-specific markers for renal cell carcinoma, ESR, LDH, CEA, alpha 2-globulin, haptoglobin, fibrinogen and various hormones have been investigated. In the treatment of bladder cancer, it is important to distinguish the malignant potential of the tumor. From this viewpoint, various immunohistochemical investigations and flow cytometric analysis are now in progress. It is expected that some of the findings of the studies could prove to be of clinical use in the near future.
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PMID:[Significance of tumor markers in the treatment of urological malignancies]. 244 94


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