Search

CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase (alpha 2,6-ST) [EC 2.4.99.1] is developmentally regulated, shows a high degree of tissue specificity, and appears to play a role in oncogenic transformation and metastasis. In the present study, we have performed the first detailed analysis of the expression of alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates in human brain tumors. We used a polyclonal, monospecific anti-rat alpha 2,6-ST antibody and the alpha 2,6-linked sialic acid-specific lectin, Sambucus nigra agglutinin (SNA) for histochemical studies, and a human alpha 2,6-ST-specific cDNA probe for Northern analysis. Meningiomas, chordomas and craniopharyngiomas frequently expressed alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates. Among the different meningioma subtypes, meningothelial meningiomas stained more strongly with both anti-alpha 2,6-ST antibody and SNA than the fibroblastic and anaplastic meningiomas. On the other hand, all tumors of glial origin and medulloblastomas were virtually devoid of either alpha 2,6-ST or alpha 2,6-linked sialoglycoconjugate expression. Moreover, very weak to negligible expression of both alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates was observed in brain metastases. In conclusion, alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugate expression is associated with non-neuroectodermal epithelial-like tumors.

We compare testosterone (T) metabolism in primary cultures of epithelial cells and fibroblasts separated from benign prostate hypertrophy (BPH) and prostate cancer tissues. In all cultures, androstenedione (delta 4) formed by oxidation of T by 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) represented 80% of the metabolites recovered. The amounts of 5 alpha-dihydrotestosterone (DHT), formed by reduction of T by 5 alpha-reductase (5 alpha-R), were small: 5 and 2% (BPH) and 8 and 15% (adenocarcinoma) for epithelial cells and fibroblasts, respectively. Northern blot analysis of total RNA from epithelial cells (BPH or adenocarcinoma) attributed the reductive activity to the 5 alpha-reductase type 1 isozyme and oxidative activity to the 17 beta-HSD type 2. In cancer fibroblasts, only little 17 beta-HSD type 2 mRNA was detected. The 5 alpha-reductase inhibitors, 4-MA (17 beta-(N,N-diethyl)carbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one) and finasteride, inhibited DHT formation with a preferential action of 4-MA on epithelial cells (BPH or adenocarcinoma) and of finasteride on fibroblasts from adenocarcinoma. Neither inhibitor acted on delta 4 formation. On the other hand, the lipido-sterol extract of Serenoa repens (LSESr, Permixon) inhibited the formation of all the T metabolites studied [IC50 S = 40 and 200 micrograms/ml (BPH) and 90 and 70 micrograms/ml (adenocarcinoma) in epithelial cells and fibroblasts, respectively]. These results have important therapeutic implications when selecting appropriate treatment options for BPH.

Amphiphilic monomers and dimers of acetylcholinesterase (AChE) and hydrophilic tetramers of butyrylcholinesterase (BuChE) were released by extracting human meningioma with Tris-saline and Tris-saline-Triton X-100 buffers. The amphiphilic or hydrophilic behavior of the AChE and BuChE forms was assessed by sedimentation analysis, hydrophobic chromatography and Triton X-114 phase-partitioning. A significant fraction of the amphiphilic AChE species was converted into hydrophilic components by incubation of the soluble enzyme with phosphatidylinositol-specific phospholipase C (PIPLC) from Bacillus thuringiensis, this fraction being increased by a double treatment with PIPLC and alkaline hydroxylamine. A significant amount of the membrane-bound AChE was released by incubation with PIPLC. These results demonstrate that AChE forms in meningioma are attached to the membrane via glycosylphosphatidylinositol, although part of the enzyme forms are resistant to PIPLC.

The biosynthesis of a given glycosphingolipid is under the control of specific glycosyltransferases, while its catabolism is catalyzed by step-wise action of glycosidases. The net amount of glycolipids apparently result from the difference between these two processes. However, other parameters should be taken into consideration, such as intracellular recycling of catabolic products, membrane insertion, and membrane turnover. In order to establish a possible correlation between ganglioside expression in brain tumor and the activities of the enzymes involved in their metabolism, we analyzed the activities of specific sialyltransferases (SAT-1 and SAT-2), galactosyltransferase (GalT-4), N-acetylgalactosaminyltransferase (GalNAcT-1), and N-acetylglucosaminyltransferase (GlcNAcT-1) in 9 human meningiomas whose ganglioside pattern was characterized either by the predominance ganglioside GM3 (4 out of 9) or ganglioside GD3 (5 out of 9). The results indicated a strong correlation between the GM3/GD3 ratio and SAT-2 activity; to the contrary, SAT-1 activity did not show any correlation if compared with the Lc2/GM3 ratio. In all the samples where GM3 was the main ganglioside, little or no activity of GalNAcT-1 and GlcNAcT-1 was detectable.

Key growth factor-receptor interactions involved in angiogenesis are possible targets for therapy of CNS tumors. Vascular endothelial growth factor (VEGF) is a highly specific endothelial cell mitogen that has been shown to stimulate angiogenesis, a requirement for solid tumor growth. The expression of VEGF, the closely related placental growth factor (PIGF), the newly cloned endothelial high affinity VEGF receptors KDR and FLT1, and the endothelial orphan receptors FLT4 and Tie were analyzed by in situ hybridization in normal human brain tissue and in the following CNS tumors: gliomas, grades II, III, IV; meningiomas, grades I and II; and melanoma metastases to the cerebrum. VEGF mRNA was up-regulated in the majority of low grade tumors studied and was highly expressed in cells of malignant gliomas. Significantly elevated levels of Tie, KDR, and FLT1 mRNAs, but not FLT4 mRNA, were observed in malignant tumor endothelia, as well as in endothelia of tissues directly adjacent to the tumor margin. In comparison, there was little or no receptor expression in normal brain vasculature. Our results are consistent with the hypothesis that these endothelial receptors are induced during tumor progression and may play a role in tumor angiogenesis.

O6-methylguanine-DNA methyltransferase (MGMT) activity was measured in 68 tissue samples taken from brain. A wide range in activity among samples was observed, with all nonmalignant samples showing transferase activity (Mer+) but approximately 15% of WHO grade II low-grade astrocytomas and WHO grade IV glioblastoma multiformes lacking activity (Mer-). On average, astrocytomas and glioblastomas showed less transferase activity than either nonmalignant tissue or meningiomas. Monoclonal antibodies specific for MGMT showed both cytoplasmic and nuclear staining of Mer+ brain tumor cells in culture but no staining of Mer- cells in culture. In pathology specimens from anaplastic astrocytomas, glioblastoma multiformes, and meningiomas, antibody staining revealed both cytoplasmic and nuclear MGMT, while one sample showed little or no MGMT-specific staining. These results help explain why nitrosoureas have been among the most successful agents in treatment of brain tumors and indicate the subcellular localization for the repair activity, which may be relevant to nitrosourea resistance.

Meningioma benign tumors possess significant levels of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity. Two different 17 beta-HSDs have been cloned and characterized. The cytosolic 17 beta-HSD I which exclusively catalyzes the interconversion of 17 beta-estradiol (E2) and estrone (E1) preferentially uses NADP+ and NADPH as cofactors. In contrast, the mitochondrial-microsomal 17 beta-HSD II catalyzes both the estrogenic as well as the androgenic substrates of the 17 beta-HSD and uses NAD+ and NADH as cofactors. We demonstrated here that the 17 beta-HSD activity in meningioma tissue homogenate is both estrogenic and androgenic with Km values of 2.4, 0.4, 14.7, and 2.0 microM for E2, E1, testosterone (T), and delta 4-androstenedione (delta 4), respectively. NAD(+)-NADH is almost exclusively used as cofactor in this tissue. Moreover, fractionation of meningioma tissue revealed that most of the 17 beta-HSD activity is present in the mitochondrial-microsomal fraction. Although Northern blot analysis on meningiomas with a specific probe for human 17 beta-HSD I showed no band, the specific cDNA probe of human 17 beta-HSD II hybridized at the expected size of 1.5 kb, which was also present in placenta. On four different meningioma tumors, we were able to correlate 17 beta-HSD II mRNA expression to high levels of 17 beta-HSD activity. Taken together, the present data suggest that the meningioma 17 beta-HSD could be the 17 beta-HSD II.

The role of matrix metalloproteinases (MMP's) and their inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1), in human brain tumor invasion was investigated. Gelatinolytic activity was assayed via gelatin zymography, and four MMP's (MMP-1, MMP-2, MMP-3, and MMP-9) and TIMP-1 were immunolocalized in human brain tumors and in normal brain tissues using monoclonal antibodies. The tissue was surgically removed from 44 patients: glioblastoma (five cases), anaplastic astrocytoma (six cases), astrocytoma (four cases), metastatic tumor (six cases), neurinoma (10 cases), meningioma (10 cases), and normal brain tissue (three cases). Glioblastomas, anaplastic astrocytomas, and metastatic tumors showed high gelatinolytic activity and positive immunostaining for MMP's; TIMP-1 was also expressed in these tumors, but some tumor cells were negative for the antibody. Astrocytomas had low gelatinolytic activity and the tumor cells showed no immunoreactivity for MMP's and TIMP-1. Although neurinomas and meningiomas had only moderate proteinase activity and exhibited positive immunoreactivity for MMP-9, intense expression of TIMP-1 was simultaneously observed in these tumor cells. These findings suggest that MMP's play an important role in human brain tumor invasion, probably due to an imbalance between the production of MMP's and TIMP-1 by the tumor cells.

The M2-type pyruvate kinase was purified from human meningioma by ammonium sulfate precipitation, followed by ion exchange and affinity chromatography. The specific activity of the purified enzyme was 33.4 U/mg with a yield of 6.5%. The enzyme gave a single band with 63,000 +/- 2000 Da upon SDS polyacrylamide gel electrophoresis. On cellulose acetate electrophoresis zymograms, the purified enzyme (M2) showed a single band, while crude extracts gave two broad bands corresponding to pyruvate kinase isozymes. The pI value of purified enzyme was found to be 6.9. With phosphoenol pyruvate as substrate the purified enzyme showed sigmoidal kinetics, while in the presence of 0.6 mM fructose 1,6-diphosphate as modulator it gave a hyperbolic saturation curve with a Km value of 0.53 mM.

Cranial hyperostosis is a common secondary manifestation of intracranial meningiomas. This may occur with or without neoplastic invasion, apart or even remote from the growth. Alkaline phosphatase (AP) is one of many enzymes produced by meningiomas and is known to possess indirect ossifying properties. Meningiomatous cranial hyperostosis could possibly be mediated by a humoral mechanism. This hypothesis was tested using chemical and histochemical determination of the occurrence of the enzyme in a series of hyperostosing and non-hyperostosing meningiomas. In the hyperostosing type the content of AP was in average more than three times as high as in the non-hyperostosing type. The results thus are in favour of the induction hypothesis.

Lactate dehydrogenase (LDH) isoenzymes were studied in biopsy samples obtained from 100 benign and malignant brain tumors. Diagnosis was confirmed by histopathology. It is observed that all tumors investigated had elevated LDH activity and showed a LDH isoenzyme pattern which is different from that of normal brain. A pronounced cathodal shift was seen in malignant tumors like medulloblastoma, grade 3-4 astrocytomas and neuroblastomas, whereas anodal pattern was seen in benign tumors like grade 1-2 astrocytomas and oligodendrogliomas. Some tumors like meningiomas showed a midzone pattern like increased LDH3. It was possible to differentiate certain tumors on the basis of LDH isoenzyme pattern like medulloblastomas into differentiated and undifferentiated; craniopharyngiomas into recurring and non-recurring ones. LDH1/LDH5 ratio was low (< 1.0) in malignant tumors and high (5.0-14.0) in benign tumors and it was useful in differentiating tumors according to the degree of malignancy and biological behavior. It is observed that both LDH isoenzyme pattern and LDH1/LDH5 ratio could be used as an adjuvant to histopathological grading of brain tumors.

A localization of copper and zinc-superoxide dismutase (Cu, Zn-SOD) in meningiomas was examined with immunohistochemical technique. Meningiomas include five meningotheliomatous, five transitional, two fibroblastic, and one of each angioblastic, malignant and hemangiopericytic types. The Cu, Zn-SOD localized diffusely in the cytoplasm of tumor cells and in the endothelial cell of vessels and neutrophils, macrophages and red blood cells in the vessels or in the tumor tissue. The Cu, Zn-SOD content in meningiomas was markedly higher in angioblastic, malignant and hemangiopericytic than in meningotheliomatous, transitional and fibroblastic types.

In addition to the important role of leukotrienes as mediators in allergy and inflammation, these compounds are also linked to pathophysiological events in the brain including cerebral ischemia, brain edema, and increased permeability of the blood-brain barrier in brain tumors. Although brain tumors have been shown to secrete leukotrienes, no studies to date have provided evidence for the tumor expression of genes encoding enzymes involved in leukotriene production. Therefore, the present study determined the abundance of the mRNA for arachidonate 5-lipoxygenase (5-LO; arachidonate:oxygen 5-oxidoreductase, EC 1.13.11.34), which is the rate-limiting enzyme in leukotriene synthesis, in a series of human brain tumors. Macrophage/monocyte infiltration of the tumor was estimated by measuring the abundance of the transcript for the 91-kDa glycoprotein phagocyte-specific oxidase (gp91-phox), which is the phagocyte-specific cytochrome b heavy chain. The present study shows that (i) the 5-LO transcript is expressed in normal bovine brain and in human brain tumors; (ii) the 5-LO gene in human brain tumors and in the dimethyl sulfoxide-induced promyelocytic human leukemic HL-60 cells is expressed as a multitranscript family (2.7, 3.1, 4.8, 6.4, 8.6 kilobases); and (iii) the abundance of 5-LO transcripts, the expression of the larger transcripts, and the 5-LO/gp91-phox ratio correlate with the tumor malignancy. Overall, the present study supports the hypothesis that the 5-LO gene product may play a role in human tumor-induced brain edemas and provides evidence for tumor-associated expression of high molecular weight 5-LO transcripts in human brain tumors.

In the present study the mechanism of action of M2-type pyruvate kinase from human meningioma in the simultaneous presence of fructose 1,6 diphosphate and L-alanine was investigated. Purified pyruvate kinase from human meningioma was allosterically inhibited by L-alanine with respect to substrates phosphoenolpyruvate and ADP. The inhibitory effects of L-alanine was partially removed by fructose 1,6 diphosphate. The purified enzyme was slightly susceptible to ATP inhibition.

A 13-year-old boy with an anaplastic meningioma at the site of the jugular foramen had an increased serum level of aklaline phosphatase (ALPase) (liver form) in the serum before surgery. Immediately after excision of the tumor, the serum ALPase level decreased dramatically. Histochemical and immunohistochemical examinations revealed ALPase activity (liver form) in the neoplastic cells. This case would be the third with clinical evidence that the increased level of serum ALPase is of neoplastic cell origin from the meningioma. The implications of ALPase in brain tumors are discussed.

It has been reported previously that most human meningiomas have receptors for somatostatin. Here we report the results of investigations of the effect of somatostatin and the somatostatin analog octreotide on the growth in vitro of human meningioma cells. Neither somatostatin nor its analog showed a direct growth inhibitory action on cultured human meningioma cells. Rather, there was a slight but significant stimulation of growth in the presence of somatostatin. The somatostatin receptors in meningioma tissue were shown to be functional since somatostatin inhibited forskolin-stimulated formation of cAMP by meningioma membranes. In addition, cAMP inhibited the growth of cultured meningioma cells. We conclude that the stimulation by somatostatin of the growth of human meningioma cells in vitro is caused by its inhibitory effect on cAMP formation. These results suggest that therapeutic trials of patients with (recurrent) inoperable meningiomas with somatostatin analogs have to be carried out with great caution.

Transglutaminase (TG) activity was measured in tissue samples of 45 human brain tumors (pituitary adenomas, meningiomas and gliomas) obtained during neurosurgery. Biochemical analysis and histopathological classification were carried out in the same samples. Mean enzyme activity was highest in non-glial tumors, but due to a high variability of values no significant changes were found between the various histological groups. Thus, TG activity, although considered to play a role in neoplastic growth, does not represent a biochemical marker of malignancy in human brain tumors.

The anatomical arrangement of the pia mater suggests that it may act as a regulatory interface between cerebrospinal fluid and the surface of the brain and between arterioles within the brain and the surrounding neural tissue. However, the functional aspects of such a barrier are difficult to evaluate in vivo. In the present study, the enzymic content and endocytotic capacities of normal leptomeningeal cells in situ and meningioma cells in confluent tissue culture are examined in relation to barrier functions of meningeal cells. Growth of cells in culture was obtained from human fetal and newborn rat leptomeninges and from 9/13 meningiomas. But, in only two meningiomas were the cultured cells characterized as meningeal in origin by using the strict criteria of desmosomes identified by immunocytochemistry or by electron microscopy. These two tumours had high (8-8.7%) Ki-67 labelling indices. Glutamine synthetase activity is present in normal meninges and in meningioma cells in culture; this enzyme together with catechol-O-methyltransferase could play a role in limiting the diffusion of neurotransmitters into brain tissue. A steady rate of endocytosis of carbon particles and fluorescent latex beads, 0.2-1 microns in diameter, was observed in cultured meningioma cells. Such endocytosis was inhibited by cytochalasin B indicating the active participation of intracellular microfilaments. Similar endocytosis has been observed in normal leptomeninges in vivo. The results of this study suggest that meningioma cells in culture reflect the barrier functions of the pia mater and may be used as a model to further investigate the functions of the pia mater.

The O6-alkylguanine-DNA alkyltransferase (AT) activity in different kinds of human brain tumors was investigated. Twenty-seven brain tumors were analysed. Twenty-five of them showed proficient AT activity with values ranging between 20 and 722 fmol AT/mg protein. The two AT-deficient tumors observed were an oligodendroglioma and an astrocytoma. The relationship between the different histological kinds of tumor, with respect to the AT activity was: meningeomas greater than sarcomas greater than glioblastomas greater than astrocytomas greater than oligodendrogliomas greater than neurinomas greater than lymphomas. The proposal of Kohn (DNA filter elution methods in anticancer drug development. In: Concepts, Clinical Developments, and Therapeutic Advances in Cancer Chemotherapy. Editor: F.M. Muggia. Martinus Nijhoff Publishers, Boston) to confine treatments with alkylating antineoplastic agents to AT-deficient tumors, is discussed.

Glutamine synthetase (GS) activity was measured in selected areas of three normal brains and in 262 biopsies from patients with suspected intracranial tumours. In general, levels were higher in grey matter than in white matter and the highest activities of all were found in the hypothalamus which is consistent with its high glutamatergic activity. In the biopsy material, GS activity was greatest in gliotic brain, in keeping with the predominantly astrocytic localization of the enzyme. High levels were also found in astrocytomas and oligodendrogliomas but there was considerable variation between tumours, suggesting a random loss of GS expression during neoplastic transformation or heterogeneity in their cellular origin. The immunocytochemical demonstration of GS in neoplastic oligodendrocytes and in meningioma cells argues against absolute cell-type specificity for this enzyme.

Ultracytochemical features of microvessels and tumor cells of the human meningiomas were examined by light and electron microscopy with special reference to the distribution of Mg2(+)-ATPase and alkaline phosphatase (ALPase) activity on the walls of the vessels and tumor cell surfaces. Materials used were 4 cases of meningiomas, 2 of which were meningotheliomatous type, one fibroblastic type and one malignant meningioma respectively. For ultracytochemistry, specimens were quickly fixed in an ice-cold 0.1 M cacodylate buffer containing 8% sucrose (pH 7.2) for one hour and transferred to a substrate solution for detection of Mg2(+)-ATPase and ALPase. The preparations were incubated at 37 degrees C for 15-30 min in the medium described by Mayahara et al. for ALPase and for 15-20 min in the medium described by Wachstein and Meisel. The control samples were incubated in a medium containing 1 mM Bromotetramisole for ALPase and also in a substrate free medium for Mg2(+)-ATPase. At the light microscopy, Mg2(+)-ATPase and ALPase activities appeared to be mainly restricted to the capillary wall and around or in the tumor cell nest showing whorl formation. Both enzyme activities were negative in the control study. By electron microscopy, reaction products representing Mg2(+)-ATPase activity were distributed in the basolateral plasma membrane of the endothelial cells on the surface of the pericytes and on the surface of the tumor cells. Reaction products of ALPase activity located mainly on the abluminal surfaces of the endothelial cells and in some specimen on both luminal and abluminal surfaces of those cells. Intense reaction products were distributed evenly on all round surfaces of the tumor cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Xanthine oxidase is most recognized for its role as the rate-limiting enzyme in nucleic acid degradation through which all purines are channelled for terminal oxidation. The enzyme serves as a source of oxygen-derived free radicals which induce both cellular injury and edema as well as changes in vascular permeability. In the study we compared xanthine oxidase levels of human brain tumors with normal brain tissues. Statistical evaluation of our results shows significantly higher xanthine oxidase levels in tumoral brain tissues. However, xanthine oxidase has not any significance for the differentiation of tumor types among each others. The oncotypes studied were meningioma and astrocytoma.

In tissue samples of 45 operated astrocytomas and of 45 meningiomas the fibrinolytic and proteolytic activity was determined by means of fibrin-agar-plate-method. In astrocytomas significant higher values of fibrinolysis were found than in the meningiomas. In the course of tumor cell necrosis or as a result of brain damage caused by the operation, proteins inducing fibrinolysis are liberated. In some cases they can lead to localized or generalized disturbances of haemostasis.

Human normal dura mater containing arachnoid villi were examined for their expression of glutathione S-transferase placental type (GST-pi), a detoxifying enzyme, using an immunohistochemical method. All of the arachnoid villi and arachnoid cells in five normal cases were found to have expression of GST-pi, although no positive reaction for the enzyme was present in other tissues of the dura mater. The results show a possible role for arachnoid tissues in protecting human brain from hazardous xenobiotics in the cerebrospinal fluid. Twenty-six meningiomas were also examined for expression of the enzyme. Tissues of meningotheliomatous meningiomas were always positive for expression of the enzyme. Transitional meningiomas also showed the expression in their meningotheliomatous components. No staining reaction of GST-pi was recognized in fibroblastic meningiomas except for two cases with a tendency to meningotheliomatous differentiation. The findings suggest a functional similarity between the arachnoid tissues and meningotheliomatous components of meningiomas.

17 beta-Hydroxysteroid dehydrogenase (E2-DH) activity was characterized on a semipurified microsomal preparation of human meningioma tissue (mean Km of 2 microM and Vmax of 500 pmol/mg protein/10 min) and then assayed in 49 meningioma specimens with high progesterone receptor and low estrogen receptor levels. Of these 49 tumors, 36% contained an E2-DH activity greater than 1,000 pmol/mg protein/10 min and similar to that of uterine myometrium. In this limited series of tumors, no correlation between E2-DH activity and progesterone receptor levels was noted.

Adenylate-kinase activity was measured in cerebrospinal fluid (C.S.F.) from 35 healthy control subjects and 11 patients with brain tumours, of which 9 were malignant and 2 benign. No adenylate kinase could be detected in C.S.F. from the controls or from the patients with benign brain tumours. The enzyme was consistently found in C.S.F. from patients with malignant brain tumours.

Biopsies from 15 human gliomas, five meningiomas, four Schwannomas, one medulloblastoma, and four normal brain areas were analyzed for 12 enzymes of energy metabolism and 12 related metabolites and cofactors. Samples, 0.01-0.25 microgram dry weight, were dissected from freeze-dried microtome sections to permit all the assays on a given specimen to be made, as far as possible, on nonnecrotic pure tumor tissue from the same region. Great diversity was found with regard to both enzyme activities and metabolite levels among individual tumors, but the following generalities can be made. Activities of hexokinase, phosphorylase, phosphofructokinase, glycerophosphate dehydrogenase, citrate synthase, and malate dehydrogenase levels were usually lower than in brain; glycogen synthase and glucose-6-phosphate dehydrogenase were usually higher; and the averages for pyruvate kinase, lactate dehydrogenase, 6-phosphogluconate dehydrogenase, and beta-hydroxyacyl coenzyme A dehydrogenase were not greatly different from brain. Levels of eight of the 12 enzymes were distinctly lower among the Schwannomas than in the other two groups. Average levels of glucose-6-phosphate, lactate, pyruvate, and uridine diphosphoglucose were more than twice those of brain; 6-phosphogluconate and citrate were about 70% higher than in brain; glucose, glycogen, glycerol-1-phosphate, and malate averages ranged from 104% to 127% of brain; and fructose-1,6-bisphosphate and glucose-1,6-bisphosphate levels were on the average 50% and 70% those of brain, respectively.

Enzymatic determinations of four enzymes, Arylsulphatase A (ARSA), alpha-iduronidase (IDUA), beta-galactosidase (GLB) and hexosaminidase were performed in 19 cases of meningioma. Gene dosage effect was demonstrated for ARSA and IDUA; preliminary evidence for mapping a "protective protein" of GLB in the region 22pter----q11 was also obtained.

In gliomas a shift was found in the composition of enzymes, manifested by abnormal inhibition of pyruvate kinase by alanine. This study demonstrates the appearance of the MII-type isoenzyme in various gliomas. This MII type is also found in meningiomas but not in normal brain tissue. The method of enzyme examination described may be valuable as a diagnostic aid in the surgery of gliomas.

Ten primary and two metastatic central-nervous system (C.N.S.) tumours were assayed. They all contained dihydrofolate reductase. This finding provides a biochemical rationale for antifolate therapy of C.N.S. tumours by methotrexate.

The lactate dehydrogenase (LDH) isoenzyme patterns in benign and malignant brain tumours were determined by means of electrophoresis of the cell extracts and selective cytochemical stain of the smears. The LDH isoenzyme distribution of the cell extracts showed a pronounced cathodal shift in the malignant gliomas and metastatic carcinomas. Normal brain tissues and histologically benign gliomas, however, showed an anodal pattern with a dominance of the H-type LDH. Schwannomas and meningiomas had a midzone isoenzyme pattern with a dominant LDH3 fraction. Pituitary adenomas usually showed the LDH pattern similar to that of the normal cerebrum. The LDH M fraction could be cytochemically verified using an inhibitory effect by 2.6 M urea in staining. Astrocytomas grades 3-4 and metastatic carcinomas were characterized by loss or marked reduction of stainability by urea treatment, while astrocytomas grades 1-2 and oligodendrogliomas were resistant to urea inhibition.

Glutathione peroxidase (GSHPx) activity was assayed in normal cerebral gray and white matter samples obtained from frontal, temporal, occipital and parietal lobes during surgical approach to an underlying lesion, and also in normal autopsied human frontal gray and white matter. GSHPx was assayed by a 2 step enzyme reaction which was monitored by following the oxidation of NADPH at 340 nm. It was found that all the brain samples studied contained GSHPx activity. Parietal lobe appeared to have the lowest GSHPx activity compared to temporal, occipital or frontal lobes. Mean enzyme activity in autopsied samples was comparable to that in surgical material. However, considerable loss of activity was observed after 10 years of tissue storage at -80 degrees C.

Fresh human brain-tumor samples were assayed for their plasminogen activator (PA) content. Specific molecular weight patterns were identified for each of five common brain tumors and for normal brain, suggesting a cell-specific origin of the various PA forms. Malignant tumors contained higher PA activity and a larger number of molecular weight patterns than benign tumors, with the exception of acoustic neurinomas. Irradiated tumors contained lower PA activity than nonirradiated tumors. Finally, a slight but definite correlation between brain edema and PA activity was detected. The future role of brain-tumor PA's for diagnostic and therapeutic purposes is discussed.

Brain benign tumors /hypophyseal adenoma, meningeoma/ caused definite effects on the enzymes of pentosephosphate pathway in blood of patients. Distinct decrease in glucose-6-phosphate dehydrogenase /G6PD/ activity was observed in erythrocytes of patients with adenoma of hypophysis as compared with a control group; transketolase /TK/ activity was unaltered. In blood of patients with brain meningeomas the G6PD was activated by 8% and TK - by 36%. Within the first day after resection of the tumors activity of the enzymes was distinctly increased; it remained markedly higher than the enzymatic activity before the operation within all the periods studied /5-7 days and 10-15 days after the operation/.

Glutamine synthetase (GS) was studied in a range of human brain tumours and compared with results obtained by staining for glial fibrillary acidic protein (GFAP) using the indirect immunoperoxidase and peroxidase-anti-peroxidase methods. All astrocytomas showed positive staining with GS, the degree of which was related to the extent of differentiation and the amount of cytoplasm of the constituent cells. Ependymomas were only weakly positive, although a dense GFAP reaction was detected around blood vessels; possibly due to the presence of astrocyte foot processes. Medulloblastomas showed signs of astrocytic differentiation by the presence of clusters of positively staining cells amongst undifferentiated neoplastic cells. Oligodendrocytomas and meningiomas were generally negative apart from occasional astrocytes within the former neoplasms. GS and GFAP staining corresponded in virtually all cases; however, GS demonstrated poorly-fibrillated cells better than GFAP, but did not show cell processes so clearly. Although GS appears to be cell-specific in the central nervous system for normal, reactive and neoplastic astrocytes, it is not organ-specific and therefore also stains cells of other tissues, e.g. liver. GS offers a practical alternative to GFAP as an astrocyte specific marker in human cerebral tumours and may be of diagnostic value in cases where poorly-differentiated astrocytic tumours have been found negative to conventional histological stains for glial fibres or demonstrate a weak positive reaction to GFAP.

The activities of five hydrolytic enzymes (acid and alkaline phosphatase, hexosaminidase [N-acetyl-beta-D-glucosaminidase], beta-galactosidase, and beta-glucorinidase) were measured in reconstituted homogenates of lyophilized human brain tissue and primary and metastatic tumors. The linearity of reaction, with respect to incubation time, and optimal pH of each enzyme and in tumor tissues were comparable to those in normal brain tissue. Total enzyme activities of hexosaminidase, beta-glucuronidase, and beta-galactosidase were significantly higher in tumors than in normal cerebral white matter. The ratio of hexosaminidase activity to beta-glucuronidase activity was significantly lower for metastatic than for primary tumors or normal white matter. When histological observations do not clearly establish if a brain tumor is primary or metastatic, this ratio may help. Alteration of hydrolytic enzyme activities as demonstrated here may be indicative of "ket enzymes" that are essential for maintaining the metabolic advantages of tumors.

The activities of serum sialyltransferase were determined in patients with brain tumors. Blood samples from normal volunteers were used as controls. Serum specimens were obtained from patients with brain tumors both before and after operations. The preoperative serum sialyltransferase activities of the brain metastasis group showed significant increase, but the enzyme levels decreased after removal of the tumor. The serum sialyltransferase activities in the glioma group and the neurilemoma group increased significantly after operation, but no significant difference was found between the preoperative means of these two groups and that of the control. Surgical treatment produced significant differences between the preoperative and the postoperative serum sialyltransferase activities in the brain metastasis and the glioma and neurilemoma groups. Alterations of this enzyme in the blood of patients with brain tumors and its possible clinical applications are discussed.

The activities and molecular forms of cholinesterases were studied in a collection of primary brain tumors consisting of primarily gliomas and meningiomas, together with samples of forebrain taken postmortem from patients suffering from diseases unrelated to the nervous system. Both types of tumors, as well as normal forebrain, contained substantial amounts of cholinesterase activity and some gliomas contained exceptionally high levels. In both normal forebrain and meningiomas, acetylcholinesterase (acetylcholine hydrolase; EC 3.1.1.7) accounted for almost all the cholinesterase activity, but in almost all gliomas elevated pseudocholinesterase (acylcholine acylhydrolase; EC 3.1.1.8) could be detected. The cholinesterase activity of both normal forebrain and gliomas migrated on sucrose gradients as a major component of 10-11 S together with a minor component of 4-5 S. In meningiomas a light (4.5 S) form was the principal component.

Asparate and alanine aminotransferase activity is approximately the same in different lobes of cerebral hemispheres of people with an uninjured central nervous system. The maximal activity of lactate, malate and succinate dehydrogenase is in the temporal lobes and thalami, the minimal one is in the corpus callosum. The activity of aminotransferases in the brain tumour lowers: in the dedifferentiated tumour the asparate aminotransferase shows a 23-24% decrease; in the case of the meningeal sarcoma it is 2.5 times as low: the activity of alaine aminogransferase is almost 10 times as low. The activity of malate dehydrogenase decreases in the neuroectodermal tumours and sharply (almost twice) in multiform glioblastoma. In the dedifferentiated meningiomas the activity of all the dehydrogenases is increased.

Adenyl-cyclase (A-C) and Phosphodiesterase (PDE) behaviour in a large number of human cerebral tumors is reported and compared with that of normal gray and white matter. PDE is much reduced in all oncotypes. Also A-C appears reduced in all tumors except astrocytomas where enzymatic activity is similar to that of gray matter. The Authors tried to explain these changes in activity by relating them to the malignancy of the oncotypes or to their different embryologic origin.

The levels of activity to ornithine decarboxylase (ODC) and adenosylmethionine decarboxylase (AMD) were measured in various types of primary human tumors of the central nervous system (CNS) and whenever possible were related to the malignancy of the tumor graded according to histopathologic criteria. In astrocytomas ODC levels increased linearly and progressively from infratentorial pilocytic astrocytoma (grade I) to glioblastoma multiforme (grade IV) and corrected well with the degree of histologic malignancy of the tumor. AMD activity levels, however, correlated with tumor malignancy only up to grade III astrocytoma. Medulloblastomas exhibited an unusual dichotomy with regard to the levels of polyamine biosynthetic decarboxylases (PBD): Medulloblastomas had the highest ODC activities of all the CNS tumors tested but had low AMD activities. In tumors of neuroepithelial tissue ODC level increases and, when present, AMD level increases were not due to proliferation of new blood vessels, because CNS hemangioblastomas had very low levels of both PBD activities. No significant differences in either of the PBD levels were observed among the several variants of meningiomas tested, the meningotheliomatous, the transitional, and the fibrous meningiomas. However, atypical forms of meningioma, i.e., those with mitotic figures, whatever the histologic variants, had higher levels of ODC, but not of AMD, than the typical forms, i.e., those without mitotic figures.

Activities of pyrimidine nucleoside phosphorylase in brain tumors were measured and their relationship to a clinical course of the patients was investigated. Pyrimidine nucleoside phosphorylase is said to exist more quantitatively in malignant tumors such as Sarcoma 180, Ehrlich ascites carcinoma, Walker 256, and hepatoma, and very little in normal tissues. In brain tumors the activities were measured by bioassay and compared to that of Sarcoma 180. When the activity of Sarcoma 180 was expressed to be 100%, those of brain tumors were as follows: ten cases of normal brain less than 8.5; six cases of glioblastoma 39.3 +/- 30.7; five cases of astrocytoma 22.0 +/- 13.8; five cases of meningioma 22.4 +/- 13.7; two cases of oligodendroglioma 8.1 and 11.3; two cases of sarcoma 94.3 and 145.4; chordoma 48.0; ependymoblastoma 3.7; plexus papilloma 22.5; parotid cancer 43.4; ten cases of metastatic brain tumors from lung cancer 61.5 +/- 41.6; two cases from breast cancer 28.0 and 68.8; that from thyroid cancer 10.0; that from gastric cancer 13.5; malignant melanoma 77.2. In 12 cases of gliomas (glioblastoma, astrocytoma, oligodendroglioma) the mean activity was highest in glioblastoma (39.3), followed by astrocytoma (22.0) and oligodendroglioma (9.7). The postoperative survival time became shorter in gliomas with the higher activities. In metastatic brain tumors from lung, breast, and gastric cancer, the average time from the diagnosis of primary cancer to brain metastasis was shorter in cases with high activities and longer in cases with low activities.(ABSTRACT TRUNCATED AT 250 WORDS)

The total activities of lactate dehydrogenase (LD) and the LD isoenzyme distribution were determined on homogenates from 61 benign and malignant intracranial tumours, and in serum and cerebrospinal fluid from 45 and 28 of the tumour patients respectively. The LD activity and the LD isoenzyme distribution in serum were not changed in patients with intracranial tumours. The LD activity in the cerebrospinal fluid was raised in about 50% of the tumour patients, but without any significant differences between patients with benign and malignant tumours. Except for very low activities in acoustic schwannomas and in pituitary adenomas, the tumour tissue did not differ significantly from normal brain in total LD activity. The LD isoenzyme distribution showed a pronounced cathodal shift in the grade 3-4 astrocytomas and the metastatic carcinomas, but an anodal shift in the grade 1-2 astrocytomas and the oligodendrogliomas. The meningiomas and the ocoustic schwannomas showed a midzone isoenzyme pattern with a dominant LD3 fraction. Knowledge of the LD isoenyme distribution can thus sometimes be a complement to the histological examination in the classification of brain tumours.

Deoxythymidine kinase (TK) is an enzyme involved in DNA synthesis. It can be used as a marker of cell proliferation. TK was measured in extracts of human brain tumours and non-neoplastic brain tissue. In astrocytomas the mean TK activity increased with increasing grade of malignancy. Oligodendrogliomas showed higher TK activity than astrocytomas. The highest activities were noted in menigiomas, of which the recurrent ones exceeded the primary in TK activity. In non-neoplastic brain tissue lower TK activity was found. It is concluded that TK can be measured in human brain tumour extracts, and is potentially of use for studies on tumour cell proliferation.