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

---

Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alkaline phosphatases (ALPase) (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.1) are implicated in many biologic phenomena including ossification and differentiation of human neutrophils and choriocarcinoma cells. Another trait, demonstrated by microinjection into Xenopus oocytes, is their ability to block the first mitotic division. Previous work in our laboratory has established that ALPase is also present on murine B lymphocytes activated by either polyclonal mitogens or Th cells. We have now characterized the ALPase present on murine B cells as belonging to the liver-bone-kidney isoenzyme and found it to be implicated in B cell differentiation into antibody secretion. Thus, B cell proliferative responses, elicited either by high concentrations of rabbit anti-IgM antibodies or by LPS in the presence of PMA, are characterized by the lack of both antibody secretion and expression of ALPase activity. In contrast, B cells stimulated to differentiate into Ig-secreting cells by B cell differentiation factors, nearly in the absence of a proliferative response, express high levels of ALPase activity, as did those that were LPS-stimulated. These data showing the association of the ALPase expression with the process of B cell differentiation into antibody-secreting cells are discussed in the context of the possible role that phosphorylation-dephosphorylation mechanism may play in controlling the growth/differentiation rate in the B cell lineage.
...
PMID:Expression of alkaline phosphatase in murine B lymphocytes. Correlation with B cell differentiation into Ig secretion. 278 37

The unique curability of gestational trophoblastic tumors may in part be attributable to a host immunologic response. The occurrence of rapidly progressive and fatal choriocarcinoma may be favored by histocompatibility between patients and their partners. However, histocompatibility is not a prerequisite for the development and persistence of gestational choriocarcinoma. The expression of HLA by choriocarcinoma cells in culture is enhanced following incubation with gamma-interferon and this may be of both biologic and clinical significance. Complete molar pregnancy is a complete allograft because all molar chromosomes are of paternal origin. Patients with complete mole are sensitized to paternal HLA antigen which is expressed in molar tissue. Other polymorphic antigen systems including trophoblast-leukocyte common antigens and placental-type alkaline phosphatase are also expressed in molar tissue. We have studied the immunopathology of the molar implantation site to investigate possible humoral and cellular immune responses. The relationships among normal placenta, complete mole and choriocarcinoma are not clearly understood. The pattern of expression of oncofetal antigens in these three gestational tissues may be used to assess trophoblastic differentiation. In studies to date, molar trophoblast has the same pattern of expression of oncofetal antigens as normal placental trophoblast. We will review recent advances in our understanding of the immunobiology of gestational trophoblastic disease and suggest new directions for further research.
...
PMID:Immunobiology of complete molar pregnancy and gestational trophoblastic tumor. 303 May 77

Placental alkaline phosphatase (PLAP)-specific monoclonal antibody (MAb) 11-D-10, which did not react with other isoenzymes of alkaline phosphatase (AP), was raised by a hybridoma technique. MAb 11-D-10 was radiolabeled and administered to athymic mice bearing human choriocarcinoma containing PLAP. This antibody was found to be more specifically localized in tumor tissue as compared to normal tissues. The tissue-to-blood ratio (T/B ratio) of MAb 11-D-10 in tumor tissue increased from 1.38 at 2 days to 2.51 at 5 days after administration. On the other hand, the T/B ratios of isotype control non-immunized IgM in tumor tissue were 0.72 and 0.87 at 2 days and 5 days after administration, respectively. 131I-labeled MAb 11-D-10 was administered to athymic mice bearing choriocarcinomas of various sizes and various PLAP contents to examine the effect on the radioimage of the differences in tumor size and PLAP content. Tumors less than 0.3 cm in diameter could be imaged clearly by gamma-scintigraphy without blood pool image subtraction. The strength of the radioimage correlated fairly well with PLAP content.
...
PMID:Radioimmunodetection of human choriocarcinoma xenografts by monoclonal antibody to placental alkaline phosphatase. 308 27

The molecular nature of an osteosarcoma-associated antigen was investigated with the three monoclonal antibodies Ost6 (immunoglobulin (IgG1), Ost7 (IgG1), and Ost15 (IgG2a), which selectively react with frozen sections of osteosarcoma and chondrosarcoma tissues. When tested with a panel of 41 human cell lines in the mixed hemadsorption assay, the antibodies reacted similarly with three of six osteosarcomas, one choriocarcinoma, one teratoma, and one osteoblast-like culture, but failed to react with 32 lines of normal and other tumor cell types. Immunoprecipitation plus sodium dodecyl sulfate (SDS)--polyacrylamide gel electrophoresis and sequential immunoprecipitation studies revealed that in [35S]methionine- or [14C]glucosamine-labelled osteosarcoma cells the three antibodies detected a single glycoprotein, with an apparent molecular mass of 86 kilodaltons (kDa), which was not affected by reducing conditions. Tunicamycin treatment and pulse-chase experiments showed glycosylation of this molecule to be N-linked; it arose from a 54-kDa polypeptide precursor. Alkaline phosphatase activity was detected in the material rich in 86-kDa molecules that was immunoprecipitated from serologically reactive cell lines with each antibody. These antibodies also cross-reacted with two isoenzymes of alkaline phosphatase (strongly with the liver and bone, and moderately with the placental isoenzyme), but not with the intestinal form.
...
PMID:Identification of a human osteosarcoma-associated glycoprotein with monoclonal antibodies: relationship with alkaline phosphatase. 333 Dec 86

Membrane and soluble forms of alkaline phosphatase (ALP) were selectively prepared from human placental microsomes by treatment with 1-butanol at pH 8.5 and 5.5, respectively. The purified membrane (mALP) and soluble (sALP) forms were analyzed for chemical compositions. mALP was found to contain 1 mol each of palmitate, stearate, and glycerol/subunit of ALP, which were absent in sALP. Both the forms contained 1 mol of inositol and 2 mol of ethanolamine/subunit. However, none of these compounds was detectable in another soluble form prepared by treatment with papain, which is known to cleave the carboxyl-terminal region. The results suggest that mALP contains diacylglycerol, the removal of which results in its conversion to sALP. We then prepared [3H]ethanolamine-labeled ALP by incubating choriocarcinoma cells (JEG-3) with the isotope. 3H-Labeled sALP was mixed with unlabeled sALP and treated with papain. A 3H-labeled single component was purified from the digests by sequential chromatography through anti-ALP-IgG-Sepharose, concanavalin A-Sepharose, Bio-Gel P-6, and TSK G-2000 columns. Chemical analyses revealed that the purified sample contains the tripeptide Thr-Thr-Asp, ethanolamine, glucosamine, mannose, inositol, and phosphate. Molar ratios of the latter five compounds were calculated to be 2, 1, 3, 1, and 2, respectively, by taking Asp as 1 mol. The tripeptide sequence was identified at positions 482-484 in the primary structure deduced from the cDNA sequence, which predicts a further extension to position 513, containing a hydrophobic amino acid sequence. Taken together, these results suggest that the mature ALP molecule lacks the predicted carboxyl-terminal peptide extension and is attached at Asp484 with a glycosylphospholipid, the components of which are characterized above. The glycosylphospholipid thus attached is considered to function as the membrane anchor of ALP.
...
PMID:Chemical characterization of the membrane-anchoring domain of human placental alkaline phosphatase. 339 21

The expression of human placental-type alkaline phosphatase (ALPase) in the placenta and in three choriocarcinoma cell lines was examined by translation in vitro and RNA blot analysis using a cDNA for placental ALPase. Placental RNA directed the synthesis of two polypeptides that could be immunoprecipitated with antiserum to placental ALPase. Translation of RNA from the choriocarcinoma cell lines, with or without sodium butyrate treatment, yielded a single immunoprecipitable product of molecular weight intermediate between those of the products from the placenta mRNA. Two cDNA clones for placental ALPase were isolated by antibody screening of a placental cDNA library constructed in lambda gt11. The overlapping cDNAs include 462 nucleotides of coding sequence. RNA blot analysis has confirmed that induction of placental-type ALPase levels during placental development is accompanied by an increase in steady-state placental ALPase mRNA concentrations. Examination of the mRNAs revealed a placental ALPase mRNA of 3.0 kilobases (kb) and a distinct choriocarcinoma placental-type ALPase mRNA of 2.6 kb, implying that transformation of normal to malignant trophoblast is associated with the expression of a distinct placental-type ALPase gene transcript and its protein product.
...
PMID:Expression of different-sized placental alkaline phosphatase mRNAs in placenta and choriocarcinoma cells. 345 56

In the presence of methotrexate, cultured human choriocarcinoma (BeWo) cells undergo a differentiative response that resembles normal trophoblastic development. In the current study, the effects of cell number and population density on drug-induced conversion of BeWo cells from the cytotrophoblastlike to the syncytiotrophoblastlike phenotype were investigated using as markers of differentiation formation of "giant" cells, a process shown to require exogenous purines, and expression of placental (heat-stable) alkaline phosphatase. Giant cell formation, assessed by determination of cell volumes, was reduced in crowded cultures, and addition of hypoxanthine to growth media partially restored methotrexate-induced cell enlargement. Cellular uptake of methotrexate, assessed by following the loss of methotrexate from cell culture fluids during drug exposures, was two-threefold greater in sparsely populated than in densely populated cultures. Although the concentration of methotrexate in culture fluids of crowded cultures declined during exposures of 48 hr, the amount of extracellular drug remaining at 48 hr was well above the threshold for induction of the differentiative response. When culture population was held constant and population density was manipulated by varying the substratum available to cells, methotrexate-induced cell enlargement was inversely related to population density. Expression of placental alkaline phosphatase, salvage of exogenous hypoxanthine, and synthesis of RNA were also reduced at high population densities. These results indicate that expression of markers of methotrexate-induced differentiation of BeWo cells was inhibited in a density-dependent manner that may have been related to reduced cellular uptake of the inducing agent and of exogenous nutrients (purines) from culture fluids.
...
PMID:Density-dependent inhibition of expression of syncytiotrophoblastic markers by cultured human choriocarcinoma (BeWo) cells. 374 81

Eight independent cell lines, derived from human testicular germ-cell tumors, were examined for the expression of various markers. These included major histocompatibility and embryonic antigens, chorionic gonadotropin, alpha fetoprotein, alkaline phosphatase, plasminogen activator, and infectivity by SV40. No line consisted primarily of choriocarcinoma or yolk sac cells, but several contained cells resembling murine embryonal carcinoma; some of these lines formed tumors with the distinctive features of embryonal carcinoma when injected into immunosuppressed animals. It is proposed that human embryonal carcinoma cells, unlike those of the mouse, correspond to a preblastocyst stage of development.
...
PMID:A comparative study of eight cell lines derived from human testicular teratocarcinoma. 616 54

In the five kinds of human cultured cells derived from ovarian adenocarcinoma (HOC-21), ovarian malignant teratoma (HOTC 3), carcinoma of the uterine endometrium (HEC-1B), squamous cell carcinoma of the uterine cervix (SKG-1) and choriocarcinoma (BeWo), the intracellular presence of lactic dehydrogenase (LDH), alkaline phosphatase (AlP), human chorionic gonadotropin (HCG), alpha-fetoprotein (AFP) and plasminogen activator were investigated. The results were as follows. 1) BeWo-, HOC-21-and HOTC 3-cells revealed high activity of intracellular presence of lactic dehydrogenase (LDH), alkaline phosphatase (AlP), human chorionic gonadotropin (HCG), alpha-fetoprotein (AFP) and plasminogen activator were investigated. The results were as follows. 1) BeWo-, HOC-21-and HOTC 3-cells revealed high activity of intracellular LDH in this order, however none of HEC-1B-and SKG-1-cells did. 2) The activity of intracellular AlP was higher in BeWo-cells than in HOC-21-cells. The isozymes of AlP detected in these cells were found to be heat-stable. The others revealed no activity of AlP. 3) The presence of HCG-beta was confirmed in both BeWo- and HOTC 3-cells. The intracellular levels of HCG-beta were found to be higher in BeWo- cells than in HOTC 3-cells. HCG-beta was observed to leak into culture medium not from HOTC 3-cells but from BeWo-cells. It was not detected in the other cultured cells. 4) No AFP was detected in any of these five cultured cells. 5) Plasminogen activator was detected in HOC-21, HEC-1B-and SKG-1-cells in contrast to HOTC 3-and BeWo-cells which were negative for plasminogen activator. These results suggest that the various marker substances detected in the human cultured cells originated from various carcinomas of sexual organs may reflect biological functions of these tumor cells and, furthermore, can apply as tumor markers to the clinical diagnosis of the diseases.
...
PMID:[Studies on marker substances in cell lines derived from various human gynecologic tumors (author's transl)]. 617 49

Alkaline phosphatase is a useful and reliable marker of germ cell neoplasia that has been almost completely overlooked in the recent medical literature and in the practice of surgical pathology. Its presence in immature germ cells and in germ cell cancers was noted as early as 1953, but a systematic study of its use in the diagnosis and classification of germ cell tumors has not appeared in the literature. Using a recently developed plastic embedding technique combined with enzyme histochemistry, a large series of germ cell tumors and gonadal specimens were examined for the presence of alkaline phosphatase. The neoplastic germ cells in all cases of seminoma and embryonal carcinoma showed strong plasma membrane positivity for alkaline phosphatase. Choriocarcinomas (gestational and nongestational) and mature teratomas were negative. These findings suggest that the alkaline phosphatase reaction is a useful adjunct in the diagnosis of germ cell cancers.
...
PMID:Alkaline phosphatase histochemistry in human germ cell neoplasms. 619 86


<< Previous 1 2 3 4 5 Next >>

---