acid-phosphatase and Astrocytoma

Somatic cells do not have telomerase activity but immortalized cell lines and more than 85 % of the cancer cells show telomerase activation to prevent the telomere from progressive shortening. The activation of this enzyme has been found in a variety of human tumors and tumor-derived cell lines, but only few studies on telomerase activity in human brain tumors have been reported. Here, we evaluated telomerase activity in different grades of human astrocytoma and meningioma brain tumors. In this study, assay for telomerase activity performed on 50 eligible cases consisted of 26 meningioma, 24 astrocytoma according to the standard protocols. In the brain tissues, telomerase activity was positive in 39 (65 %) of 50 patients. One sample t test showed that the telomerase activity in meningioma and astrocytoma tumors was significantly positive entirely (P < 0.001). Also, grade I of meningioma and low grades of astrocytoma (grades I and II) significantly showed telomerase activity. According to our results, we suggest that activation of telomerase is an event that starts mostly at low grades of brain including meningioma and astrocytoma tumors.

Topics: Acid Phosphatase; Adult; Aged; Astrocytoma; Brain Neoplasms; Enzyme-Linked Immunosorbent Assay; Female; Humans; Isoenzymes; Male; Meningioma; Middle Aged; Neoplasm Grading; Tartrate-Resistant Acid Phosphatase; Telomerase

The plasma membrane from the human tumor astrocytoma contains an active acid phosphatase activity based on hydrolysis of p-nitrophenyl phosphate. Other acid phosphatase substrates--beta-glycerophosphate, O-phosphorylcholine, and 5'-AMP--are not hydrolyzed significantly. The phosphatase activity is tartrate insensitive and is stimulated by Triton X-100 and EDTA. Of the three known phosphoamino acids, only free O-phosphotyrosine is hydrolyzed by the membrane phosphatase activity. Other acid phosphatases tested from potato, wheat germ, milk, and bovine prostate did not show this degree of specificity. The plasma membrane activity also dephosphorylated phosphotyrosine histone at a much greater rate than did the other acid phosphatases. pH profiles for free O-phosphotyrosine and phosphotyrosine histone showed a shift toward physiological pH, indicating possible physiological significance. Phosphotyrosine histone dephosphorylation activity was nearly 10 times greater than that seen for phosphoserine histone dephosphorylation, and Km values were much lower for phosphotyrosine histone dephosphorylation (0.5 microM vs. 10 microM). Fluoride and zinc significantly inhibited phosphoserine histone dephosphorylation. Vanadate, on the other hand, was a potent inhibitor of phosphotyrosine histone dephosphorylation (50% inhibition at 0.5 microM) but not of phosphoserine histone. ATP stimulated phosphotyrosine histone dephosphorylation (160-250%) but inhibited phosphoserine histone dephosphorylation (95%). These results suggest the existence of a highly specific phosphotyrosine protein phosphatase activity associated with the plasma membrane of human astrocytoma.

Topics: Acid Phosphatase; Astrocytoma; Cell Line; Cell Membrane; Humans; Hydrogen-Ion Concentration; Neoplasms, Experimental; Phosphoprotein Phosphatases; Phosphoproteins; Phosphoserine; Phosphotyrosine; Substrate Specificity; Tyrosine

Topics: Acid Phosphatase; Animals; Astrocytoma; Brain Neoplasms; Bucladesine; Cell Division; Glucuronidase; Humans; Neoplasms, Experimental; Rats

The tartrat resistant zinc activated acid phosphatase (ZT-AP) was investigated in 17 glial microtumours of the rat brain. The tumours were induced by N-ethyl-N-nitrosourea injected to newborn rats subcutaneously (85 mg/kg body weight). The morphology of these microtumours corresponds to the statements in the literature. In regard to their behaviour of the investigated enzyme the microtumours may be divided in 2 groups: 1) Microtumours with an activity of acid phosphatases but without any histochemically demonstrable activity of ZT-AP. Histologically they correspond to oligodendric microgliomas. 2) Microtumours with a high activity of acid phosphatases and a remarkable activity of ZT-AP especially in the perivascular cell proliferations. This type corresponds histologically to the astrocytic and mixed glial proliferations including glioblastomas. According to our present findings the ZT-AP was found in astrocytes and especially in mesenchymal cells. In some cases a focal increased activity of ZT-AP could also be observed before histological alterations appeared. We regard it as an early stage of the development of tumours.

Topics: Acid Phosphatase; Animals; Astrocytoma; Brain Neoplasms; Ethylnitrosourea; Female; Histocytochemistry; Male; Oligodendroglioma; Rats; Rats, Inbred Strains; Stimulation, Chemical; Tartrates; Zinc

Topics: Acid Phosphatase; Animals; Astrocytoma; Brain Neoplasms; Female; Glioma; Golgi Apparatus; Lysosomes; Macrophages; Maternal-Fetal Exchange; Neoplasms, Experimental; Neurilemmoma; Nitrosourea Compounds; Oligodendroglioma; Pregnancy; Rats; Rats, Inbred Strains

Topics: Acid Phosphatase; Animals; Astrocytoma; Brain Neoplasms; Cells, Cultured; Culture Techniques; Ependymoma; Glioblastoma; Glioma; Glucosephosphate Dehydrogenase; L-Lactate Dehydrogenase; Mice; Mice, Inbred C3H; Neoplasms, Experimental; Succinate Dehydrogenase

Topics: Acid Phosphatase; Adolescent; Adult; Aged; Alcohol Oxidoreductases; Alkaline Phosphatase; Astrocytoma; Brain Neoplasms; Female; Glioma; Glutamate Dehydrogenase; Glycerolphosphate Dehydrogenase; Histocytochemistry; Humans; L-Lactate Dehydrogenase; Male; Middle Aged; Oligodendroglioma; Succinate Dehydrogenase

Topics: Acid Phosphatase; Adenoma, Chromophobe; Astrocytoma; Biopsy; Brain Neoplasms; Choroid Plexus; Ependymoma; Glioblastoma; Hemangiosarcoma; Histocytochemistry; Humans; Medulloblastoma; Meningioma; Neurilemmoma; Oligodendroglioma; Papilloma; Pituitary Neoplasms; Rosaniline Dyes; Sarcoma; Staining and Labeling

Topics: Acid Phosphatase; Adenoma, Chromophobe; Ameloblastoma; Astrocytoma; Biopsy; Brain; Brain Neoplasms; Cell Differentiation; Cerebellar Neoplasms; Cerebellum; Choroid Neoplasms; Choroid Plexus; Ependyma; Ependymoma; Esterases; Ganglia; Ganglioneuroma; Hemangiosarcoma; Histocytochemistry; Humans; Medulla Oblongata; Medulloblastoma; Meninges; Meningioma; Neuroectodermal Tumors, Primitive, Peripheral; Neuroma; Neurons; Oligodendroglioma; Pituitary Gland; Pituitary Neoplasms; Sarcoma

Topics: Acid Phosphatase; Astrocytoma; Cerebral Ventricle Neoplasms; Choroid Plexus

Topics: Acid Phosphatase; Alkaline Phosphatase; Aminopeptidases; Animals; Astrocytoma; Brain Neoplasms; Ependymoma; Esterases; Glioma; Histocytochemistry; Methylcholanthrene; Mice; Oligodendroglioma

Topics: Acid Phosphatase; Astrocytoma; Brain Chemistry; Brain Neoplasms; Cytoplasm; Ependymoma; Esterases; Glioblastoma; Histocytochemistry; Humans; Lymphoma, Large B-Cell, Diffuse; Medulloblastoma; Neoplasm Metastasis; Neurilemmoma; Phosphates; Physostigmine

Topics: Acid Phosphatase; Adenosine Triphosphatases; Alkaline Phosphatase; Astrocytoma; Brain Neoplasms; Carcinoma; Ependymoma; Esterases; Glioma; Glucosyltransferases; Histocytochemistry; Humans; Meningioma; Neurilemmoma; Oligodendroglioma; Sarcoma

Topics: Acid Phosphatase; Adenosine Triphosphate; Alkaline Phosphatase; Astrocytoma; Brain; Brain Neoplasms; Cerebellar Neoplasms; Dihydrolipoamide Dehydrogenase; Electron Transport Complex II; Ependyma; Esterases; Glioblastoma; Glucose-6-Phosphatase; Hemangiosarcoma; Histocytochemistry; Intracranial Arteriosclerosis; L-Lactate Dehydrogenase; NAD; NADP; Oligodendroglioma; Succinate Dehydrogenase

Topics: Acid Phosphatase; Alkaline Phosphatase; Astrocytoma; Brain; Brain Neoplasms; Esterases; Glioblastoma; Glioma; NAD; NADP; Neurochemistry; Oligodendroglioma; Oxidoreductases