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)

The emerging clinical relevance of bone marrow micrometastasis has prompted several investigations, using a variety of immunocytochemical approaches. The present study was designed to evaluate some of the variables affecting the immunocytochemical detection of individual epithelial tumor cells in bone marrow. Using an alkaline phosphatase-antialkaline phosphatase staining technique, we evaluated bone marrow aspirates from 358 patients with primary carcinomas of the breast (n = 150), lung (n = 66), prostate (n = 42), or colorectum (n = 100). Individual tumor cells in cytological preparations were detected with monoclonal antibody (MAb) CK2 to the epithelial cytokeratin component 18 (CK18), which has been validated in extensive clinical studies. In addition, the utility of the broad-spectrum MAb A45-B/B3 was explored in this study. The high specificity of MAbs CK2 and A45-B/B3 was supported by analysis of bone marrow from 75 noncarcinoma control patients and by double-marker analysis with MAbs to mesenchymal marker proteins (CD45 and vimentin). In contrast, MAbs E29 and HMFG1, directed to mucin-like epithelial membrane proteins, cross-reacted with hematopoietic cells in 26.7-42.7% of all samples tested. The majority of the 154 positive samples (43.0%) from cancer patients displayed less than 10 CK18-positive cells per 8 x 10(5) marrow cells analyzed. The detection rate, however, was affected by blood contamination of the aspirate, the number of aspirates analyzed, and the number of marrow cells screened per aspiration site. Comparative immunostaining of bone marrow specimens with MAbs CK2 and A45-B/B3 indicated that downregulation of CK18 in micrometastatic carcinoma cells occurs in about 50% of the 172 samples analyzed, regardless of the primary tumor origin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Methodological analysis of immunocytochemical screening for disseminated epithelial tumor cells in bone marrow. 753 Jan 32

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

Microtubule-associated protein 1b, previously also referred to as microtubule-associated protein 5 or microtubule-associated protein 1x, is a major component of the juvenile cytoskeleton, and is essential during the early differentiation of neurons. It is required for axonal growth and its function is influenced by phosphorylation. The distribution of microtubule-associated protein 1b in kitten cerebellum and cortex during postnatal development was studied with two monoclonal antibodies. Hybridoma clone AA6 detected a non-phosphorylated site, while clone 125 detected a site phosphorylated by casein-kinase II. On blots, both monoclonal antibodies stained the same two proteins of similar molecular weights, also referred to as microtubule-associated protein 5a and 5b. Antibody 125 detected a phosphorylated epitope on both microtubule-associated protein 1b forms; dephosphorylation by alkaline phosphatase abolished the immunological detection. During development of cat cortex and cerebellum, AA6 stained the perikarya and dendrites of neurons during their early differentiation, and especially labelled newly generated axons. The staining decreased during development, and axonal staining was reduced in adult tissue. In contrast to previous reports which demonstrated that antibodies against phosphorylated microtubule-associated protein 1b label exclusively axons, antibody 125 also localized microtubule-associated protein 1b in cell bodies and dendrites, even in adulthood. Some nuclear staining was observed, indicating that a phosphorylated form of microtubule-associated protein 1b may participate in nuclear function. These results demonstrate that microtubule-associated protein 1b is subject to CK2-type phosphorylation throughout neuronal maturation and suggest that phosphorylation of microtubule-associated protein 1b may participate in juvenile and mature-type microtubule functions throughout development.
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PMID:Differential phosphorylation of MAP1b during postnatal development of the cat brain. 776

Minimal residual disease in patients with operable esophageal cancer is frequently missed by current noninvasive tumor staging. Here we applied an immunocytochemical cytokeratin assay that allows identification of individual esophageal carcinoma cells disseminated to bone marrow. Prior to therapy, bone marrow was aspirated from the upper iliac crest of 71 patients with esophageal cancer at various disease stages as well as an age-matched control group of 20 noncarcinoma patients. Tumor cells in cytologic bone marrow preparations were detected with monoclonal antibodies (mAbs) CK2, KL1, and A45-B/B3 to epithelial cytokeratins (CKs) using the alkaline phosphatase antialkaline phosphatase method. CK-positive cells were found in 14 (36.8%) of 38 cancer patients treated with curative intent and 16 (48.5%) of 33 patients with extended disease. The overall frequency of these cells was 1 per 4 x 10(5) to 82 per 4 x 10(5) mononuclear cells with no significant differences between patients at different tumor stages. After a short median follow-up of 9.5 months (3-24 months), 7 of 11 patients who underwent complete surgical resection but had tumor cells in bone marrow presented with tumor relapse compared to 2 of 19 corresponding patients without such cells (p < 0.01). It was concluded that although bone marrow is not a preferential site of overt metastasis of esophageal cancer, the frequent occurrence of isolated tumor cells at this distant site indicates that hematogenous dissemination of viable malignant cells occurs early in tumor progression.
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PMID:Disseminated epithelial tumor cells in bone marrow of patients with esophageal cancer: detection and prognostic significance. 866 32

In the present study, epithelial cells in the bone marrow of 42 patients with pancreatic carcinoma were identified immunocytochemically with monoclonal antibodies (MAbs) CK2, KL1 and A45-B/B3 directed to epithelial cytokeratins (CK), using the alkaline phosphatase anti-alkaline phosphatase method. The specificity of the MAbs was demonstrated by negative staining of marrow from 25 non-carcinoma age-matched control patients. Analysis of bone marrow aspirates from cancer patients revealed CK-positive cells in 14 (58.3%) of 24 cancer patients treated with curative intent and 10 (55.6%) of 18 patients with extended disease. After a median follow-up of 15.6 months (range 3-31 months), 5 (35.7%) out of 14 patients who underwent complete surgical resection but had tumour cells in bone marrow presented with distant metastasis and 6 (42.9%) with local relapse as compared to none of 10 corresponding patients without such cells (P < 0.05). The described technique may help to identify patients with pancreatic cancer and potential high risk of early metastatic relapse. The results promise to be of important assistance in determining prognosis and consequences in therapy of early stage pancreatic cancer.
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PMID:Epithelial tumour cells in bone marrow of patients with pancreatic carcinoma detected by immunocytochemical staining. 866 55

We have reported that purified native MAP1B interacts with microtubules but not with microfilaments [Pedrotti and Islam, Cell Motil. Cytoskel. (1995) 30, 301-309]. However, MAP1B can be phosphorylated at multiple sites by casein kinase 11 (CKII) and proline-directed protein kinases (PDPK) and immunoblotting studies show that purified native MAP1B is phosphorylated at least at two CKII sites and at one PDPK site [Pedrotti et al., Biochemistry (1996) 35, 3016-3023]. We now show that phosphorylation affects the in vitro binding of MAP1B with microfilaments. Native MAP1B does not bind to microfilaments but after treatment with alkaline phosphatase the dephosphorylated MAP1B binds and cosediments with microfilaments. Dephosphorylation kinetics suggest that the PDPK site, but not CKII sites, may negatively regulate the interaction with F-actin. The ability of dephosphorylated MAP1B to crosslink microfilaments was also examined and showed that MAP1B exhibits only a weak crosslinking of F-actin when compared with MAP2.
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PMID:Dephosphorylated but not phosphorylated microtubule associated protein MAP1B binds to microfilaments. 869 71

Occult dissemination of tumor cells mainly determines the prognosis of patients with primary prostate cancer. The effect of androgen deprivation on micrometastatic tumor cells in these patients is currently unknown. We therefore used an immunocytochemical assay with monoclonal antibodies (MAbs) directed against epithelial cytoskeleton proteins (i.e., cytokeratins) to monitor the concentration of isolated tumor cells in the bone marrow of 36 prostate cancer patients (stage C), who underwent hormonal androgen deprivation with Flutamide and Leuprorelin acetate. Tumor cells in cytologic bone marrow preparations were detected using an assay that employed the MAb CK2 directed against cytokeratin (CK) 18 and the alkaline anti-alkaline phosphatase staining method. Prior to therapy, we detected between 1 and 38 CK-positive cells per sample of 2 x 10(6) nucleated cells in 21 patients, while the remaining 15 patients displayed tumor-free marrow samples. There was no significant correlation between the concentration of CK-positive cells and the volume of hypo-echogenic lesions as an indicator of the primary tumor volume or the serum level of prostate-specific antigen (PSA). After androgen deprivation, 20 of the 21 initially positive patients either became negative (n = 16) or showed at least a reduction in the concentration of CK-positive cells (n = 4). Moreover, only 2 of the 15 patients with negative pre-treatment findings became positive. All of the 7 patients with remaining tumor cells in the bone marrow after therapy showed no detectable amounts of PSA in their serum. Our findings suggest that serum PSA concentration is no indicator of micrometastatic disease in bone marrow. Neoadjuvant androgen deprivation appears to eliminate disseminated CK-positive tumor cells present in bone marrow, a preferred site of overt metastasis in prostate cancer patients.
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PMID:Immunocytochemical monitoring of micrometastatic disease: reduction of prostate cancer cells in bone marrow by androgen deprivation. 917 3

Minimal residual disease in patients with operable pancreatic carcinoma is frequently missed by current noninvasive tumour staging. We applied an immunocytochemical cytokeratin assay that allows identification of individual pancreatic carcinoma cells disseminated to bone marrow. Prior to therapy, bone marrow was aspirated from the upper iliac crest of 48 patients with ductal adenocarcinoma of the pancreas at various disease stages and an age-matched control group of 33 noncarcinoma patients. Tumor cells in cytologic bone marrow preparations were detected with monoclonal antibodies (mAbs) CK2, KL1, and A45-B/B3 to epithelial cytokeratins (CK) using the alkaline phosphatase antialkaline phosphatase method. CK-positive cells were found in 14 (48.4%) of 31 cancer patients treated with curative intent and in 10 (58.8%) of 18 patients with extended disease. The overall frequency of these cells was 1 to 83 per 5x10(5) mononuclear cells with no significant differences between patients at different tumor stages and lymph node involvement. After a median follow-up of 22.8 months (range 3-48 months), 6 (40.0%) of 15 patients who underwent complete surgical resection but had tumor cells in bone marrow presented with distant metastasis and 7 (46.7%) had local relapse compared to none of 12 corresponding patients without such cells (p<0.05). Univariate survival analyses revealed that the presence of CK-positive cells was predictive of reduced overall survival. In conclusion, anticytokeratin mAbs are reliable probes for the immunocytochemical detection of single pancreatic cancer cells disseminated to bone marrow. Thus the described technique may help identify patients with pancreatic cancer and at potentially high risk of early metastatic relapse. The results promise to be of important assistance for determining prognosis and the consequences in therapy of early stage pancreatic cancer.
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PMID:Micrometastases in bone marrow: prognostic indicators for pancreatic cancer. 1044 15

Immobilization of native proteins, retaining their activity, on the solid support is often crucial for a variety of biochemical assays involving protein-protein interactions. In this study we describe a technique which allows binding of both complex (protein kinase CK2) and simple (calf intestine alkaline phosphatase, CIP) enzymes to the solid support without denaturization of the proteins. This method is based on the covalent cross-linking of the enzymes to the bifunctional resin, containing the secondary amino and thiol groups, in a coupling reaction with the imidoester dimethyl pimelimidate hydrochloride. Both enzymes in their bound form were active in the specific biochemical assays. We also found that the CK2 and CIP resins did not change their activity for at least 3 months, and the quality of these resins were not affected by high salts or reducing agents. Thus, this method can be recommended for general use to generate active enzymes coupled to the solid support.
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PMID:A method of immobilization on the solid support of complex and simple enzymes retaining their activity. 1080 37

Choline acetyltransferase synthesizes acetylcholine in cholinergic neurons and, in humans, may be produced in 82- and 69-kDa forms. In this study, recombinant choline acetyltransferase from baculovirus and bacterial expression systems was used to identify protein isoforms by two-dimensional SDS/PAGE and as substrate for protein kinases. Whereas hexa-histidine-tagged 82- and 69-kDa enzymes did not resolve as individual isoforms on two-dimensional gels, separation of wild-type choline acetyltransferase expressed in insect cells revealed at least nine isoforms for the 69-kDa enzyme and at least six isoforms for the 82-kDa enzyme. Non-phosphorylated wild-type choline acetyltransferase expressed in Escherichia coli yielded six (69 kDa) and four isoforms (82 kDa) respectively. Immunofluorescent labelling of insect cells expressing enzyme showed differential subcellular localization with the 69-kDa enzyme localized adjacent to plasma membrane and the 82-kDa enzyme being cytoplasmic at 24 h. By 64 h, the 69-kDa form was in cytoplasm and the 82-kDa form was only present in nucleus. Studies in vitro showed that recombinant 69-kDa enzyme was a substrate for protein kinase C (PKC), casein kinase II (CK2) and alpha-calcium/calmodulin-dependent protein kinase II (alpha-CaM kinase), but not for cAMP-dependent protein kinase (PKA); phosphorylation by PKC and CK2 enhanced enzyme activity. The 82-kDa enzyme was a substrate for PKC and CK2 but not for PKA or alpha-CaM kinase, with only PKC yielding increased enzyme activity. Dephosphorylation of both forms of enzyme by alkaline phosphatase decreased enzymic activity. These studies are of functional significance as they report for the first time that phosphorylation enhances choline acetyltransferase catalytic activity.
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PMID:Expression, purification and characterization of recombinant human choline acetyltransferase: phosphorylation of the enzyme regulates catalytic activity. 1086 Dec 22


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