Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

We established seven hybridomas secreting murine IgG monoclonal antibodies (MoAbs) to placental alkaline phosphatase (PLAP). The seven hybridomas were designated (1) 7C6, (2) 6G10, (3) 5B9, (4) 6D5, (5) 6B5, (6) 11G6 and (7) 3E10, respectively. The characteristics of these hybridomas were evaluated by radioimmunoassay (RIA) with 125I-PLAP. Their reactivity with the intestinal alkaline phosphatase, one of the alkaline phosphatase isozymes, was (1) 0.04, (2) 0.2, (3) 1.4, (4) 1.8, (5) 0, (6) 4.0 and (7) 6.2(%), respectively. None of them showed signs of cross-reactivity with the liver-type alkaline phosphatase, also one of the alkaline phosphatase isozymes, within a PLAP concentration of 2,000 IU/l. The subtype of 5B9 was IgG1, and that of the others was IgG2a. We then used 7C6, to develop a sensitive, specific and convenient enzyme immunoassay (EIA) for the determination of PLAP, and assayed sera from patients with various gynecologic diseases. The incidence of increased PLAP was 6.4% in patients with benign diseases, 21.5% in cervical cancer, 36.4% in endometrial carcinoma, and 39.5% in malignant ovarian tumors. The specificity for malignant diseases seemed to be higher than that of CA125. Among endometrial carcinomas, well-differentiated adenocarcinoma had the highest incidence of an increased concentration. Among malignant ovarian tumors, serous cystadenocarcinoma, endometrioid carcinoma, dysgerminoma and Krukenberg's tumor showed a higher incidence than the other types.
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PMID:Establishment of hybridomas secreting monoclonal antibodies to placental alkaline phosphatase and development of an enzyme immunoassay for its determination. 220 81

1. Alkaline phosphatases were purified from human placenta, bovine milk, shrimp and clam with a final spec. act. of 67,000, 32,000, 22,000 and 15,000 U/mg of protein respectively. 2. The alkaline phosphatase from Meretrix lusoria is unique with its thermostability at 65 degrees C for 30 min; whereas the remaining enzymes studied, including the human placental alkaline phosphatase, are inactivated and have negligible activities. 3. The alkaline phosphatase from Penaeus monodon can be differentiated by its pH optimum at 9.0; the remaining enzymes studied have their optimal pH at 10.0. 4. The alkaline phosphatases from shrimp and clam are proposed to be applied as "reporters" in the study of mammalian cells.
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PMID:A comparative study of alkaline phosphatases among human placenta, bovine milk, hepatopancreases of shrimp Penaeus monodon (Crustacea: Decapoda) and clam Meretrix lusoria (Bivalvia: Veneidae): to obtain an alkaline phosphatase with improved characteristics as a reporter. 222 75

The authors developed monoclonal antibodies (MoAb) against human placental alkaline phosphatase (PLAP). Four specific MoAb reacting only with PLAP and two nonspecific MoAb reacting equally with isozymes of alkaline phosphatase (hepatic, intestinal, and placental) were obtained. Immunohistochemical staining with the specific MoAb showed that the cell membrane and cytoplasm of cancer cells were stained in gastric and colorectal carcinoma. The incidence of PLAP positivity was 23% (25 of 107) of all gastric carcinomas. Among gastric carcinomas, the 42% (13 of 31) positivity of highly differentiated carcinoma (papillary adenocarcinoma and well-differentiated tubular adenocarcinoma) was a significantly higher rate than that found in poorly differentiated carcinoma (poorly differentiated adenocarcinoma and signet-ring cell carcinoma, five of 41, 12%). The incidence of PLAP positivity was 11% (four of 35) in colorectal carcinoma. In contrast, gastric adenoma, intestinal metaplasia, and noncancerous tissue adjacent to cancer did not show staining. These results indicated that expression of PLAP was apt to occur in more highly differentiated gastric carcinoma and was highly specific for carcinoma in the gastrointestinal tract, although its incidence was not high.
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PMID:Expression of placental alkaline phosphatase in gastric and colorectal cancers. An immunohistochemical study using the prepared monoclonal antibody. 224 98

We have isolated a set of complementary DNA (cDNA) clones that together encode the alkaline phosphatase of human colon cancer LS174T cells. These clones include two cDNAs isolated from a conventionally prepared oligodeoxythymidylate-primed lambda ZAP cDNA library and three cDNA clones prepared by using the polymerase chain reaction. The deduced amino acid sequence of the alkaline phosphatase primary transcript contains 532 amino acids. This enzyme is similar to, but not identical with, placental alkaline phosphatase (PLAP); it exhibits 12-19 amino acid substitutions when compared to the various alleles of PLAP. Also, it is similar to PLAP in that it is apparently attached to the cell membrane by a phosphatidylinositol-containing anchor as judged by the ability of phosphatidylinositol-specific phospholipase C to release it from membranes. It is different from PLAP however, in terms of its signal sequence which only contains 19 amino acids as compared to 22 for PLAP. Moreover, the 3'-untranslated region of the LS174T cell alkaline phosphatase message diverges considerably from the PLAP message. The LS174T cell alkaline phosphatase cDNAs are actually much more similar to the "germ cell" alkaline phosphatase gene than they are to PLAP. Only 7 amino acid substitutions exist between the LS174T cell enzyme and the alkaline phosphatase encoded by the germ cell alkaline phosphatase genomic DNA clone isolated by Millan and Manes (Proc. Natl. Acad. Sci. USA, 85: 3024-3028, 1988). Furthermore, the 3'-untranslated region of the LS174T cell alkaline phosphatase message is very similar to the sequence immediately downstream of the coding region of the germ cell alkaline phosphatase genomic DNA clone. Thus, these results indicate that this colon cancer cell alkaline phosphatase is likely to represent an allelic variant encoded at the germ cell alkaline phosphatase locus.
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PMID:Molecular cloning of complementary DNAs encoding alkaline phosphatase in human colon cancer cells. 229 57

The Xenopus oocyte is widely used to study the various aspects of eukaryotic cell structure and function. It is also being used increasingly in expression cloning of cDNAs encoding proteins for which there are no structural data. One of the drawbacks of the Xenopus oocyte system is that individual oocytes taken at the same time from the same frog vary considerably in the amount of protein synthesized from the same amount of injected mRNA. In this report we describe the preparation and use of the mRNA for a secreted mutant form of human placental alkaline phosphatase as an internal, coinjected standard to monitor translation in oocytes. Secreted alkaline phosphatase can be readily determined in the medium of cultured oocytes by using a standard colorimetric assay. The amounts of alkaline phosphatase secreted into the medium were shown to parallel the level of expression of two membrane proteins. This permits rapid identification and selection of those oocytes that efficiently express injected mRNAs. The procedure yields more precise data and results in an enormous saving of time and expense, especially in investigations that involve complex measurements on individual oocytes.
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PMID:Secreted alkaline phosphatase: an internal standard for expression of injected mRNAs in the Xenopus oocyte. 229 43

A human endometrial tumor (Ishikawa) cell line in culture responded to estradiol stimulation, as measured by growth and alkaline phosphatase activity. These effects were similar whether the medium was enriched with serum or was serum-free. Estradiol increased placental alkaline phosphatase activity 2-3-fold over control in these Ishikawa cells. The mechanism for this increase appeared to be at the level of transcription, at least in part, since there was an increase in the concentration of placental alkaline phosphatase mRNA. The administration of tamoxifen or 4-hydroxytamoxifen was unable to antagonize the estradiol-stimulated alkaline phosphatase enzyme activity or mRNA expression. The administration of tamoxifen alone had no effect on alkaline phosphatase enzyme activity, but tamoxifen did stimulate the steady state concentration of alkaline phosphatase mRNA. In contrast, a new antiestrogen, ICI 164,384, was able to antagonize both of these estradiol-stimulated effects.
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PMID:Estrogen regulation of placental alkaline phosphatase gene expression in a human endometrial adenocarcinoma cell line. 233 23

The steady-state levels of mRNAs encoding alkaline phosphatase isoenzymes were examined in two human breast carcinoma cell lines. MDA-MB-157 cells expressed the phenotypic breast alkaline phosphatase and BT20 cells expressed the nonphenotypic placental alkaline phosphatase isoenzyme, frequently reexpressed in neoplasms. Dexamethasone (DEX), which elicits a general effect on phosphatase expression, and 1,25-dihydroxy vitamin D3 (1,25(OH)2D3), a promoter of cell differentiation that correspondingly effects embryonic phosphatase expression, were chosen as perturbing agents for these experiments. RNA blot analysis showed a single RNA species of approximately 2.6 kb under all treatment conditions in BT20 cells and a single RNA species of 2.6 kb under each condition in MDA-MB-157 cells. The results showed that the expression of both the AP isoenzyme mRNA phenotypic of breast produced by MDA-MB-157 cells and the embryonic alkaline phosphatase isoenzyme (PLAP) mRNA produced by BT20 cells was increased by treatment with DEX. By comparison 1,25(OH)2D3 caused an increase in the tissue-unspecific AP mRNA in the MDA-MB-157 cells, but caused a decrease in PLAP mRNA levels in BT20 cells. The level of each isoenzyme mRNA species is altered by either hormone in a dose- and time-dependent manner in both cell lines. In BT20 cells, treatment with cycloheximide showed that ongoing protein synthesis is not required to potentiate the PLAP mRNA response to DEX, but is required for the action of 1,25(OH)2D3. However, protein synthesis is required for the action of both hormones in the MDA-MB-157 cells which make the breast phenotypic AP. These data demonstrate that the DEX- and 1,25(OH)2D3-regulated expression of both of these alkaline phosphatase isoenzymes occurs via a complex mechanism involving control of mRNA abundance, not translational control of constant message levels.
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PMID:A difference in the regulation of mRNA expression between the phenotypic and the embryonic alkaline phosphatase genes in human cancer cells. 233 89

The radioimmunotherapeutic potential of 131I-labeled monoclonal antibodies was investigated in 36 nude mice (BALB/c nu/nu) inoculated s.c. with the HeLa Hep 2 human adenocarcinoma cell line. The membrane bound tumour associated antigen placental alkaline phosphatase and several intracellular cytokeratins served as targets for the antibodies. The specific radioactivity in each organ was determined after i.p. injection of the 131I-labeled antibodies (0.2-0.3 mg, approximately 15 MBq/animal), and high localization to the tumours was seen. Significant growth inhibition was observed after injection of the radiolabeled monoclonal antibody H7 against the placental alkaline phosphatase, which reduced the tumour growth to only 12% during a 3 week period compared to a growth of more than 100% for the controls. Animal weight losses were seen. Synthesis of endogenous antibodies to the target antigens was found to be significant. Morphometric evaluation of the relations between stroma, tumour cells and necrotic areas in the tumours after radioimmunotherapy demonstrated a significant increase of the mean relative connective tissue volume and a significant decreased mean of relative volume of tumour cells in the group treated with iodinated antiplacental alkaline phosphatase antibody. This therapeutic principle is encouraging and may offer new possibilities for future treatment of some malignant diseases.
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PMID:Experimental radioimmunotherapy of HeLa tumours in nude mice with 131I-labeled monoclonal antibodies. 234 12

The expression of the heat-stable isoenzyme of alkaline phosphatase in the human and monkey (Macaca mulatta, M. fascicularis) lung was investigated at the light- and electron-microscopic level, using cytochemical techniques and immunocytochemical procedures based on monoclonal and polyclonal antibodies against human term-placental alkaline phosphatase. Both in man and monkey, the enzyme was present in type-I pneumocytes. In the monkey, the enzyme was found in all type-I cells. In man, strong staining was observed only in some type-I cells and in certain cuboidal respiratory bronchiolar cells. Staining was localized on the apical and basal plasma membrane, in apical and basal caveolae, and in the underlying basement membrane. The level of heat-stable alkaline phosphatase expression in the human lung was 10-fold lower than in the monkeys studied. In human fetal lung, the onset of heat-stable alkaline phosphatase expression was associated with the development of the alveolar epithelium from 17-20 weeks gestation onward. It is concluded that: (1) heat-stable alkaline phosphatase is a specific constituent of type-I pneumocytes in man and monkeys; and (2) its subcellular localization may explain its rapid appearance in the circulation under certain conditions.
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PMID:Heat-stable alkaline phosphatase as a marker for human and monkey type-I pneumocytes. 235 23

The placental alkaline phosphatase was purified by immunoaffinity chromatography from ovarian epithelial tumours to homogeneity. Up to 40% of the catalytical phosphatase activity in these tumours was derived from this placental type alkaline phosphatase (PLAP). The purified enzyme were similar to those of PLAP, whereas the PLAP-like isozyme was more heat-stable and resistant to 8 M urea than PLAP. The amino terminal sequence of the PLAP-like enzyme demonstrated heterogeneity at position three in the N-terminal end compared with PLAP. Phenyl-Sepharose affinity chromatography and different lectin chromatographies demonstrated the tumour-derived enzyme to be microheterogeneous, both with regard to concanavalin A binding and hydrophobicity properties.
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PMID:Purification and characterisation of the placental-like alkaline phosphatase from ovarian epithelial tumours. 238 81


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