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)

Early dissemination of malignant cells is the main cause for metastatic relapse in patients with solid tumours. By use of monoclonal antibodies (mAbs) specific for cytokeratins, disseminated individual epithelial tumour cells can now be identified in mesenchymal organs such as bone marrow. Further to characterize such cells in patients with prostate cancer, an immunocytochemical procedure was developed for simultaneous labelling of cytokeratin component no. 18 (CK18) and prostate specific antigen (PSA). In a first step, cells were incubated with mAb ER-PR8 against PSA and secondary gold-conjugated goat anti-mouse antibodies. In a second step, biotinylated mAb CK2 to CK18 was applied as primary antibody and subsequently incubated with complexes of streptavidin-conjugated alkaline phosphatase, which were developed with the Newfuchsin substrate. The binding of gold-labelled antibodies was visualized by silver enhancement. The sensitivity and specificity of the technique was demonstrated on cryostat sections of hyperplastic prostatic tissue, and cytological preparations of LNCaP prostatic tumour cells. Double staining was restricted to cells derived from the secretory epithelium of the prostate. Cross-reactivity between both detection systems was excluded by several controls, including the use of unrelated antibodies of the same isotype and the staining of CK18+/PSA- HT29 colon carcinoma cells. CK18+ cells co-expressing PSA were found in bone marrow aspirates from 5 out of 13 patients with carcinomas of the prostate, a finding that is consistent with the relative fraction of double-positive LNCaP cells. The specificity of CK18 for epithelial tumour cells in bone marrow was supported by negative staining of 12 control aspirates from patients with benign prostatic hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunocytochemical double staining of cytokeratin and prostate specific antigen in individual prostatic tumour cells. 768 10

The aim of the study was to ascertain whether the exposure to ethanol of human colon carcinoma CaCo-2 and HT-29 cell lines affects the differentiation process. As an index of enterocytic differentiation, the expression of sucrase, alkaline phosphatase, alpha 2,6-sialyltransferase toward the N-acetyllactosaminic sequence, and beta 1,4-N-acetylgalactosaminyltransferase (beta 1,4GalNAc-transferase) was examined. The latter enzyme is responsible for the biosynthesis of Sda carbohydrate histo-blood antigen, which mainly occurs in human colonic cells; its expression in CaCo-2 cells depends strictly on the enterocytic differentiation. The addition of ethanol in the culture medium resulted in a significant increment of sucrase and alpha 2,6-sialyltransferase activities in both cell lines, as well as the beta 1,4GalNAc-transferase activity in CaCo-2 cells and alkaline phosphatase activity in HT-29 cells. The increment was dose-dependent in the range between 50 and 200 mM ethanol and evident after 2 days of exposure in both cell systems. These results support the notion that, as occurs for cell lines of different origin, the ethanol in vitro positively affects the differentiation of intestinal cells, namely along the enterocytic lineage. The putative mechanism by which ethanol interferes with the maturation process of colonic cells is discussed.
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PMID:Effect of ethanol on human colon carcinoma CaCo-2 and HT-29 cell lines during the maturation process. 769 34

Calcium supplementation decreases the incidence of colon cancer in animal models and may prevent colon cancer in man. Potential mechanisms include binding of mitogens and direct effects of calcium on colonic epithelial cells. In this study, the effects of extracellular calcium on epithelial cell growth and differentiation were studied in three colon carcinoma and two colonic adenoma cell lines. The characteristics studied included morphology, cell cycle kinetics, [Ca2+]IC (intracellular calcium concentration), proliferation, and expression of differentiation markers such as carcinoembryonic antigen (CEA) and alkaline phosphatase (AP). Sodium butyrate (NaB) and 1,25-dihydroxyvitamin D3 were used as controls in the latter three assays as these two agents are known differentiating agents. Alteration of [Ca+2]EC (extracellular calcium concentration) did not affect carcinoembryonic antigen (CEA) or alkaline phosphatase (AP) expression. NaB enhanced the expression of AP three-fold and CEA five-fold. This effect was augmented by increasing [Ca2+]EC. The exposure of cells to 1,25-(OH)2-Vitamin D3 increased CEA but not AP. [Ca2+]IC increased in response to 1,25-(OH)2-vitamin D3 and NaB but not with variation in [Ca2+]EC. Increased [Ca2+]EC inhibited proliferation of well-differentiated cells, but had no effect on poorly-differentiated cells. Morphological studies showed that extracellular calcium was necessary for normal cell-cell interactions. These studies have demonstrated direct effects of calcium on colonic epithelial cells which may contribute to the protective effects of dietary calcium against colon cancer. Loss of responsiveness to the antiproliferative effects of [Ca2+]EC with de-differentiation suggests that calcium supplementation may be most beneficial prior to the development of neoplastic changes in colonic epithelium.
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PMID:The effect of extracellular calcium on colonocytes: evidence for differential responsiveness based upon degree of cell differentiation. 777 41

The polar-planar compound hexamethylene bisacetamide (HMBA) can inhibit HT29 colon carcinoma cell growth and induce a more benign phenotype, as defined by decreased anchorage-independent clonogenicity, loss of a cell surface malignancy marker, and decreased in vivo tumorigenicity. The principle aim of this study was to determine whether HMBA's effects on HT29 cell growth and biologic behavior correlate with effects on intestinal differentiation. Parallel studies were performed with sodium butyrate (NaBT), a potent inducer of intestinal differentiation. HT29 cell growth, proliferation, and markers of intestinal differentiation were assayed after short- and long-term treatment with HMBA, NaBT, or the combination. Both 5 mM HMBA and 5 mM NaBT were potent inhibitors of monolayer growth; in combination their effects were nearly additive. Inhibition of DNA synthesis was detectable within 6 h of treatment and was preceded by down-regulation of c-myc expression. Soft agar clonogenicity was also decreased by 90%, > 99%, and > 99% by HMBA, NaBT, and the combination, respectively. Despite these parallel effects on growth and in vitro markers of a benign phenotype, effects on intestinal differentiation were discordant. NaBT induced significant increases in membrane-associated alkaline phosphatase activity, cytosolic mucin content, PAS+/diastase-resistant cells, and ultrastructural evidence of intestinal cell differentiation. HMBA not only failed to induce markers of intestinal differentiation, but attenuated NaBT's effects when used in combination. These data suggest that growth and intestinal differentiation may be independently regulated in HT29 cells. They also suggest that expression of intestinal markers of differentiation is not a prerequisite for the acquisition of a more benign phenotype.
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PMID:Growth and intestinal differentiation are independently regulated in HT29 colon cancer cells. 792 96

Highly differentiated epithelial populations (36% mucin-producing cells; sixfold increase in alkaline phosphatase activity; development of flat, substrate-adherent, entero-cytic foci) were induced upon in vitro exposure of HT-29di human colon carcinoma cells to sodium butyrate (NaB). 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] (10(-7) M) and the ionophore A23187 (0.5 microM) significantly augmented (two to threefold) NaB-induced HT-29di differentiation, whereas 1,25-(OH)2D3 or A23187 alone were not effective. Induction reflected specific changes in protein abundance, involving, most notably, a differentiation-associated increase in the expression and substrate-deposition of a 47-kDa protein with pI/mw two-dimensional map coordinates and immunochemical properties identical to that of plasminogen activator inhibitor type 1 (PAI-1), a major regulator of the pericellular proteolytic cascade. Culture of HT-29di cells in medium of either high (2.5 mM) or low (0.25 mM) Ca2+ concentration did not affect the incidence of 'spontaneous' differentiation, although NaB-induced goblet cell and enterocytic maturation was Ca(2+)-dependent. The inability of 1,25-(OH)2D3, A23187 or modulated Ca2+ levels alone (i.e., in the absence of NaB) to effect differentiation of HT-29di cells and the Ca(2+)-dependence of the NaB response indicate that NaB and Ca2+ act co-operatively to induce colonic epithelial maturation in vitro.
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PMID:Expression of plasminogen activator inhibitor type 1 (PAI-1) by HT-29di human large bowel carcinoma cells is modulated as a function of epithelial differentiation. 814 46

We have developed a rapid colorimetric in situ mRNA hybridization procedure to analyze epidermal growth factor receptor (EGF-R) transcripts in paraffin-embedded surgical specimens of human colon carcinomas. This technique is based on the use of 24-base oligonucleotide probes labeled with 6 biotin molecules at the 3' end. mRNA integrity was verified using a hyperbiotinylated 30-residue-long deoxythymidylate oligonucleotide probe, and the specificity of the reaction was confirmed by using labeled EGF-R-specific sense and antisense probes. Avidin alkaline phosphatase detection and the capillary technology used in the Microprobe System allowed for completion of the procedure in under 5 h. The human A431 epidermoid carcinoma cells growing in culture and fixed with formalin as well as paraffin-embedded sections of this tumor growing s.c. in nude mice served as positive controls. In situ hybridization with antisense EGF-R oligonucleotide probes directly correlated with EGF-R mRNA and protein levels observed by Northern blot and immunohistochemistry, respectively. In situ hybridization of paraffin-embedded sections of primary human colon carcinoma and metastases from liver and lymph node revealed cell-specific staining with EGF-R antisense oligonucleotide probes that correlated directly with Northern blot and immunohistochemistry analyses. Since this rapid and sensitive in situ mRNA hybridization technique can be used in properly preserved paraffin-embedded tissue, it allows for retrospective analyses of human tumor specimens using archival material.
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PMID:A rapid colorimetric in situ messenger RNA hybridization technique for analysis of epidermal growth factor receptor in paraffin-embedded surgical specimens of human colon carcinomas. 843 66

A human colon carcinoma cell line designated OUMS-23 has been established from metastatic pericardial fluid of a male familial adenomatous polyposis patient with colon cancer. Since 1984, the epithelial cells have been maintained in culture. Ultrastructural studies revealed the presence of numerous microvilli on the cell surface and desmosomes between the adjacent cells. The cells secreted carcinoembryonic antigen into the culture medium (15 ng/10(6) cells-1 24 h-1). The cells expressed heat-stable placental-type-like alkaline phosphatase, whereas the normal counterparts expressed tissue-unspecific alkaline phosphatase. Karyotypic analysis showed that the cell line was of human origin and that the chromosome number was broadly distributed between 53 and 118. Southern blot analysis of the APC gene revealed no abnormalities in OUMS-24 cells, while Northern blot analysis demonstrated that the expression of the gene was about one-half that of the normal human fibroblasts. No mutations at the "hot spots" of codons 12 and 61 of H-, K- and N-ras proto-oncogenes were detected in the cells. The cells could grow in soft agar at a cloning efficiency of 6.5%, and upon transplantation into nude mice the cells formed tumors, which were diagnosed as differentiated adenocarcinoma.
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PMID:Establishment and characterization of a human colon cancer cell line, OUMS-23, from a patient with familial adenomatous polyposis. 857 85

Insulin-like growth factor II (IGF-II) has been implicated in the differentiation of skeletal muscle cells. In this study the putative role of IGF-II in epithelial cell differentiation was investigated. The expression of IGF-II, IGF-I receptor and IGF-II/mannose-6-phosphate receptor (IGF-II/M6P receptor) mRNA during spontaneous differentiation of the colon carcinoma cell line Caco-2 was measured. In addition, differentiation of Caco-2 cells during the cell culture period (days 1-21 in culture) was studied in parallel using morphological (light and scanning electron microscopy) and biochemical markers of growth (DNA, RNA and protein content, and beta-actin mRNA and glyceraldehyde phosphate dehydrogenase mRNA expression) and differentiation (alkaline phosphatase activity, carcinoembryonic antigen content). A putative correlation between the markers of growth and differentiation and IGF gene expression was studied using linear regression analysis. Expression of IGF-II mRNA and IGF-II/M6P receptor mRNA correlated significantly with the progress of differentiation, while the IGF-I receptor was stably expressed throughout the culture period and exhibited a crucial role for the survival of Caco-2 cells, as shown by blocking experiments employing the monoclonal anti-IGF-I receptor antibody alpha-IR3. We hypothesize that: IGF-II mRNA and IGF-II/M6P receptor mRNA are expressed in a coordinate fashion during the differentiation of Caco-2 cells; coordinate expression of IGF-II and of IGF-II/M6P receptor mRNA might point to a role for IGF-II as a growth stimulant and for the IGF-II/M6P receptor for a regulator of IGF-II bioavailability in differentiating cells; alternatively, high IGF-II/M6P receptor mRNA and protein expression in differentiated cells but low IGF-II binding to the IGF-II/M6P receptor point to an important intracellular role of this receptor type in differentiated colon epithelial cells; the IGF-I receptor mRNA is stably expressed during the differentiation process of Caco-2 cells; the IGF-I receptor protein seems to be a prerequisite for the survival of Caco-2 cells.
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PMID:Coordinate expression of insulin-like growth factor II (IGF-II) and IGF-II/mannose-6-phosphate receptor mRNA and stable expression of IGF-I receptor mRNA during differentiation of human colon carcinoma cells (Caco-2). 876 74

Enzymic, immunological and lectin-binding properties of alkaline phosphatase (AP) produced in Caco-2 cells, a human colon carcinoma cell line, were investigated. The enzyme was very similar to fetal intestinal (meconium) AP in the enzymic and immunological properties, but different from fetal intestinal AP in lectin-binding properties; expression of the galactose moiety was altered in AP of Caco-2 cells, compared to that of fetal intestinal AP. These results indicate that AP of Caco-2 cells can be used in place of fetal intestinal AP when the enzymic properties of an AP of unknown origin are investigated, but cannot be used instead of fetal intestinal AP in the structural study of AP.
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PMID:A fetal intestinal-type alkaline phosphatase produced in Caco-2 cells. 879 58

A novel bioluminescence-based solid-phase assay is described for the enzyme GDPFuc:Gal(beta)1-3GlcNAc (Fuc to GlcNAc) alpha1,4-fucosyltransferase (alpha1,4FT), which generates the Lewis a blood group antigen (Le(a)) (Gal(beta)1-3[Fuc(alpha)1-4]GlcNAc-R). Lacto-N-tetraose (LNT,Ga ta)1-3GlcNAc(beta)1-3Gal(beta)1-4Glc) was chemically conjugated to bovine serum albumin (BSA) to generate the acceptor neoglycoprotein LNT-BSA. The Le(a) product of the reaction made in the presence of the donor GDPFuc is detected with a primary monoclonal IgG antibody to Le(a) and a secondary antibody coupled to either alkaline phosphatase or the recombinant bioluminescent protein aequorin. Recombinant human GDPFuc:Gal(beta)1-3(4)GlcNAc (Fuc to GlcNAc) alpha1,4/alpha1,3-fucosyltransferase, which exhibits alpha1,4FT activity, was used to optimize the assay. With this assay alpha1,4FT activity is measurable in human serum, in human saliva, and in extracts of the human colon carcinoma cell line SW1116. Activity is absent, however, in extracts of human HL-60 and murine F9 cells, neither of which synthesize Le(a) antigen. Among 10 human donors tested, soluble alpha1,4FT activity, was measurable in serum and saliva of some, but not all donors. However, the presence of enzyme activity in sera does not correlate with Lewis blood group phenotype of erythrocytes. The saliva of one donor, which contained Le(a) antigens, exhibited no alpha1,4FT activity. That saliva was found to contain a heat-stable factor(s) capable of inhibiting the alpha1,4FT activity when mixed with donor saliva containing alpha1,4FT activity. This new assay should be useful in assessing the Lewis enzyme activity in body fluids and its relationship to the Lewis blood group status on cells and secreted glycoconjugates in normal and diseased states.
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PMID:alpha1,4-Fucosyltransferase activity in human serum and saliva. 891 40


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