Polyamines in human brain tumors. A correlative study between tumor, cerebrospinal fluid and red blood cell free polyamine levels

Tumor cell-derived spermidine promotes a pro-tumorigenic immune microenvironment in glioblastoma via CD8+ T cell inhibition

The glioblastoma microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly impact the immune system, but the mechanisms driving these interactions are not completely clear. Here we demonstrate that the polyamine metabolite spermidine is elevated in the glioblastoma tumor microenvironment. Exogenous administration of spermidine drives tumor aggressiveness in an immune-dependent manner in pre-clinical mouse models via reduction of CD8+ T cell frequency and phenotype. Knockdown of ornithine decarboxylase, the rate-limiting enzyme in spermidine synthesis, did not impact cancer cell growth in vitro but did result in extended survival. Furthermore, glioblastoma patients with a more favorable outcome had a significant reduction in spermidine compared to patients with a poor prognosis. Our results demonstrate that spermidine functions as a cancer cell-derived metabolite that drives tumor progression by reducing CD8+T cell number and function.

Polyamine Immunometabolism: Central Regulators of Inflammation, Cancer and Autoimmunity

Polyamines are ubiquitous, amine-rich molecules with diverse processes in biology. Recent work has highlighted that polyamines exert profound roles on the mammalian immune system, particularly inflammation and cancer. The mechanisms by which they control immunity are still being described. In the context of inflammation and autoimmunity, polyamine levels inversely correlate to autoimmune phenotypes, with lower polyamine levels associated with higher inflammatory responses. Conversely, in the context of cancer, polyamines and polyamine biosynthetic genes positively correlate with the severity of malignancy. Blockade of polyamine metabolism in cancer results in reduced tumor growth, and the effects appear to be mediated by an increase in T-cell infiltration and a pro-inflammatory phenotype of macrophages. These studies suggest that polyamine depletion leads to inflammation and that polyamine enrichment potentiates myeloid cell immune suppression. Indeed, combinatorial treatment with polyamine blockade and immunotherapy has shown efficacy in pre-clinical models of cancer. Considering the efficacy of immunotherapies is linked to autoimmune sequelae in humans, termed immune-adverse related events (iAREs), this suggests that polyamine levels may govern the inflammatory response to immunotherapies. This review proposes that polyamine metabolism acts to balance autoimmune inflammation and anti-tumor immunity and that polyamine levels can be used to monitor immune responses and responsiveness to immunotherapy.

Roles of nitric oxide and polyamines in brain tumor growth

Nitric oxide (NO) and polyamines: putrescine, spermidine and spermine, are key arginine metabolites in mammalian tissues that play critical roles i.a. in regulation of vascular tone (NO), and cell cycle regulation (polyamines). In the brain, both classes of molecules additionally have neuromodulatory and neuroprotective potential, and NO also a neurotoxic potential. Here we review evidence that brain tumors use the NO- and polyamine-synthesizing machineries to the benefit of their differentiation and growth from healthy glia and neurons. With a few exceptions, brain tumors show increased activities of one or all of the three arginine (Arg) to NO-converting nitric oxide synthase (NOS) isoforms (iNOS, eNOS, nNOS), but also elevated activities of polyamines-generating and modifying enzymes: arginase I/II, ornithine decarboxylase and spermidine/spermine N¹-acetyltransferase. The degree of stimulation of NO- and polyamine synthesis often correlates with brain tumor malignancy. Excess NO, but also spermine, spermidine and their N¹-acetylated forms, are tumor- and context-dependently involved in angiogenesis, tumor initiation and growth, and resistance to chemo- or radiotherapy. Hypothetically, increased demand for NO and/or polyamines is likely to contribute to Arg auxotrophy of malignant brain tumors, albeit the causal nexus awaits experimental verification.

Digestive involvement in a severe form of Snyder-Robinson syndrome: Possible expansion of the phenotype

Snyder-Robinson syndrome (OMIM #309583) is a rare X-linked condition, caused by mutation in the SMS gene (MIM *300105), characterized by a wide spectrum of clinical signs including developmental delay, epilepsy, asthenic habitus, dysmorphism, osteopenia, and renal or genital anomalies. Here we describe two maternal half-brothers who both presented with severe neurodevelopmental delay, seizures, hearing loss, facial dysmorphism, renal and ophthalmologic anomalies, failure to thrive and premature death. A novel p.(Gly203Asp) variant was found at the hemizygous state in the two boys, and an elevated Spermidine/Spermine ratio confirmed the diagnosis of Snyder-Robinson syndrome. One of the brothers presented with gastrointestinal symptoms, with jejunal stenosis, enteral feeding intolerance, failure to thrive due to a dysfunctional gastrointestinal system, cholestasis and exocrine pancreatic insufficiency. Although more studies will be needed to understand its mechanisms, this observation lends further support to the possibility of severe digestive involvement in Snyder Robinson syndrome.

Quantification of polyamines in human erythrocytes using a new near-infrared cyanine 1-(ε-succinimidyl-hexanoate)- 1′-methyl-3,3,3′,3′-tetramethyl- indocarbocyanine-5,5′-disulfonate potassium with CE-LIF detection

A novel near-infrared (NIR) cyanine 1-(epsilon-succinimidyl-hexanoate)-1'-methyl-3,3,3',3'-tetramethyl-indocarbocyanine-5,5'-disulfonate potassium (MeCy5-OSu) has been developed in our laboratory. Simultaneous determination of MeCy5-OSu-derivatized polyamines spermine (Spm), spermidine (Spd), cadaverine (Cad), and putrescine (Put) based on the separation by CE combined with diode LIF detection has been accomplished. The highest derivatization efficiency was achieved in 0.2 mol/L borate buffer (pH 8.8) for 20 min at 25 degrees C. Polyamine derivatives were separated within 14 min in the phosphate running buffer (pH 3) containing 50 mmol/L phosphoric acid, 40 mmol/L SDS, and 35% methanol v/v. Linearity of response was obtained in the range of 10-200 nmol/L. The detection limits (S/N = 3) for Spm, Spd, Cad, and Put were 0.8, 1, 3, and 2 nmol/L, respectively. The proposed method has been successfully applied to the analysis of polyamines in erythrocytes of two healthy persons and one cancer patient. Average recoveries for erythrocyte samples were 93.6-106% and coefficients of variation ranged from 1.8 to 5.4%. The analysis of polyamines in erythrocytes can be used for studying the relationship between their changes and the carcinogenesis process involved in erythrocytes.

Determination of polyamines in human tissues by precolumn derivatization with 9-fluorenylmethyl chloroformate and high-performance liquid chromatography

A high-performance liquid chromatography (HPLC) assay with fluorescence detection was developed for the determination of the polyamines putrescine, spermidine, spermine in samples of human spinal cord, cerebellum, cerebrospinal fluid (CSF), skeletal muscle, and muscle microdialysates without an extensive sample preparation. The precolumn derivatization was performed with 9-fluorenylmethyl chloroformate (FMOC), and the derivatizated polyamines were stable for at least 14 h at 4 degrees C. All polyamines were separated within 35 min. The method was checked for linearity, and mean correlation coefficient values of 0.995, 0.999, and 0.991 were achieved for putrescine, spermidine, and spermine, respectively. The within- and between-assay coefficient of variation percentages evaluated in standard solutions varied between 1.0 and 4.9% and between 1.3 and 6.9%, respectively. The corresponding values obtained in samples of human spinal cord were between 1.0 and 5.0% and between 0.6 and 5.8%. The values of the recovery, evaluated in spinal cord tissue, varied between 83.7 and 93.5%.

Atmospheric pressure chemical ionization-mass spectrometry method to improve the determination of dansylated polyamines

Determination of polyamine pools is still a step impossible to circumvent in studies aimed at determining the pathophysiological role of natural polyamines. In addition, polyamine measurement in biological fluids and tissues may have clinical relevance, especially in cancer patients. Among the wide panel of analytical methods developed for the quantification of polyamines, high-performance liquid chromatographic (HPLC) separation of polyamines after derivatization with dansyl chloride remains the most commonly used method. In this work, we show that atmospheric pressure chemical ionization-mass spectrometry (MS) can be used to detect and quantify biologically relevant polyamines after dansylation, without chromatographic separation. Positive-ion mass spectra for each dansylated polyamine were generated after optimization by flow injection analysis (FIA). FIA coupled with MS detection by selected ion monitoring greatly increased the sensitivity of the polyamine detection. The method is linear over a wide range of polyamine concentrations and allows detection of quantities as low as 5 fmol. The FIA/MS method is about 50-fold more sensitive than the conventional HPLC/fluorimetry procedure. A good correlation (r>0.98) between these two methods was observed. The FIA/MS method notably reduces the time of analysis per sample to 1.5 min and turns out to be rapid, efficient, cost saving, reproducible, and sufficiently simple to allow its routine application.

Increased red blood cell polyamines in ALS and Parkinson's disease

The polyamines spermidine (SPD) and spermine (SPM) are implicated in nerve cell degeneration and regeneration. Over 70% of circulating polyamines are associated with red blood cells (RBC). Against this background we have analysed RBC polyamines in two neurodegenerative disorders, amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). Twenty patients with the sporadic form of ALS, 20 patients with PD, and 20 healthy controls were studied. The highest levels of SPD and SPM were found in the PD group where the mean values were 134 and 115%, respectively, above those of the controls. The patients with PD also presented the lowest levels of the SPD precursor, putrescine (PUTR). In the patients suffering from ALS the SPD and SPM mean levels were increased by 46 and 112%, respectively. The RBC SPD/SPM ratio in the patients suffering from PD was significantly elevated in comparison with that of ALS patient group, suggesting a different involvement of the polyamine system in these disorders. It is at present unknown if raised polyamine levels may contribute to induce the degeneration of susceptible neurons or if the increase represents a compensatory protective reaction, or simply an unspecific epiphenomenon.

Polyamine metabolism in brain tumours: diagnostic relevance of quantitative biochemistry

OBJECTIVE

Activation of polyamine metabolism is closely associated with cellular proliferation. The purpose was to investigate whether the content of the polyamines putrescine, spermidine, and spermine, and the activity of the first metabolic key enzyme of polyamine metabolism, ornithine decarboxylase (ODC), represent biochemical markers of malignancy in brain tumours.

METHODS

The concentration of putrescine, spermidine, and spermine, and the activity of ODC were biochemically quantified in tissue samples obtained during open microsurgery of 670 patients with brain tumours. Biochemical analysis and histopathological classification were carried out in serial tumour samples.

RESULTS

The activity of ODC was very low in peritumoral non-neoplastic brain tissue (0.9 (SD 0.6) nmol/g/h). It was significantly higher in gliomas and it significantly increased with a higher grade of malignancy (grade I 2.7 (2.8) nmol/g/h, grade II 3.1 (4.0) nmol/g/h, grade III 5.7 (5.6) nmol/g/h, grade IV 10.6 (11.7) nmol/g/h). High enzyme activity was also found in medulloblastomas (25.5 (15.1) nmol/g/h), malignant lymphomas (52.1 (42.1) nmol/g/h), and metastases from carcinoma (14.9 (22.1) nmol/g/h). Lowest values were measured in epidermoid cysts (0.5 (0.2) nmol/g/h), craniopharyngiomas (1.2 (0.9) nmol/g/h), angioblastomas (1.6 (1.7) nmol/g/h), and neurinomas (2.0 (1.8) nmol/g/h). By contrast with ODC activity, polyamine concentrations did not correlate with the grade of malignancy. Correlation of regional biochemical and histomorphological data in rapidly growing neoplasms showed high enzyme activity in solid tumour parts and low activity in necrotic areas.

CONCLUSIONS

Novel data relating ODC activation and polyamine concentrations to neuropathology is presented indicating that high ODC activity represents a biochemical marker of malignancy in brain tumours. This information is important for clinical and therapeutic investigations.

Polyamine profiles in tumor, normal tissue of the homologous breast, blood, and urine of breast cancer sufferers

Polyamines are involved in the development of breast cancer. We assayed polyamines in erythrocytes, urines, and breast tissues (tumor tissue and histologically normal breast tissue close to the tumor) of patients with invasive breast cancer (n = 174) and benign breast disease (n = 71, used as controls). Polyamine levels in red blood cells and urine were similar to the polyamine concentrations found in healthy subjects, and thus cannot be used as diagnostic markers of breast cancer. In cancer tissue, polyamines were significantly increased in comparison with the polyamine concentrations in controls, and were correlated to the tumor aggressiveness as evaluated by histological grade and Ki-67 proliferative index. On the other hand, correlation was found between polyamine levels in the tumor and the status of the hormone receptors. In the mammary tissue close to the cancer, polyamines dramatically decreased in comparison with the polyamine levels of tissue samples removed around the histologically proven benign tumors. The changes of the polyamine concentrations in the histologically normal breast tissue in the vicinity of the cancer could play a role in the cancer development and need further studies, especially if polyamines are considered as a potential therapeutic target in breast cancer.

Polyamine metabolism in gliomas

Biosynthesis of the polyamines putrescine, spermidine, and spermine has been found to be activated in tissues with cellular proliferation. In the present study we have investigated polyamine levels and the activity of the first rate-limiting enzyme ornithine decarboxylase (ODC) in tumour samples obtained during operation of 202 patients with gliomas. Biochemical data were closely related to the grading of malignancy and to the morphological characteristics of each sample. Mean ODC activity was significantly higher in all gliomas as compared to peritumoural non-neoplastic brain. Furthermore, it was significantly higher (p < or = 0.001) in anaplastic gliomas who grade III and IV (9.0 +/- 9.6 nmol/g/h) than in gliomas WHO grade I and II (3.3 +/- 4.2 nmol/g/h). Highest enzyme activity (58.5 nmol/g/h) was found in solid and vital parts of malignant tumours, whereas predominantly necrotic areas exhibited low ODC activity (< 1 nmol/g/h). Thus, intra- and interindividual variability of ODC activity corresponded well to histomorphological heterogeneity in high-grade gliomas. Putrescine levels also increased with rising grade of malignancy, whereas spermidine and spermine levels did not correlate with the histological grading. In conclusion, high ODC activity represents a biochemical marker of malignancy in gliomas, but low values do not prove benignity. The present study reinforces the need of further and more extensive tumour sampling closely related to follow-up investigations in the heterogeneous group of gliomas.

Characterization of amine oxidase activities in macrophages from human peripheral blood

A sensitive assay for the determination of hydrogen peroxide formation and a method for the identification and characterization of amine oxidases in cells and other oxidase sources of limited accessibility are described. The enzymes are characterized by substrate and inhibitor patterns. The method was applied to the identification and characterization of polyamine oxidizing enzymes in macrophages from human peripheral blood. The major oxidase activity in these cells was found to be a tissue-type polyamine oxidase, but with distinct characteristics. Diamine oxidase and monoamine oxidase activities were also detected in homogenates of macrophages. Since the formation of toxic products by a releasable polyamine oxidase is supposed to be an integral part of a regulatory function of macrophages, we consider our work as a basis for the elucidation of this function.

Positron emission tomography study of human prostatic adenocarcinoma using carbon-11 putrescine

To evaluate [1-11C]putrescine ([11C]PUT) as a potential tracer for imaging and characterization of human prostatic adenocarcinoma, positron emission tomography (PET) was performed in eight patients and three normal controls. In addition, four of the patients and the three normal controls also had a prostate scan with 2-deoxy-2-[18F]fluoro-D-glucose (18FDG). Three of the patients had undergone resection of the prostate tumor and all of the patients except for one had bone metastasis. Carbon-11 rapidly accumulated in prostate, bone and rectum after injection of [11C]PUT. Maximal uptake was achieved 5 min after injection with minimal washout during the 50 min study period. The uptake of carbon-11 in the prostate of normal controls was significantly higher than that in the patients. However, three of the four patients scanned for metastatic bone lesions showed higher uptake in bone metastasis than in normal bone. Quantitation of 18FDG uptake in the prostate was hindered by the high accumulation of activity in the urinary bladder. [11C]PUT does not appear to be a useful tracer for assessing proliferation of human prostate adenocarcinoma. Its utility in the imaging of other cancers with high polyamine concentration remains to be investigated.

Diamine oxidase activity in rat brain carcinogenesis and in gliomas

In the early stages of brain carcinogenesis induced by transplacental administration of N-ethyl-N-nitrosourea to BD IX rats, a constant increase in the activity of cerebral diamine oxidase, the rate-limiting enzyme in terminal catabolism of polyamines, was observed. Gliomas, which developed between the fifth and eight month of extrauterine life, showed an 8-fold increase in enzyme activity compared with normal brain from rats of the same age. Concomitantly, an 11-fold enhancement in putrescine, a physiological substrate of diamine oxidase, was also found. Such findings indicate that an increase in oxidative putrescine catabolism via diamine oxidase takes place in transformed cells and in gliomas and is probably linked to an activation of polyamine synthesis and turnover.

Polyamine metabolism in experimental brain tumors of rat

Biosynthesis and accumulation of the polyamines putrescine, spermidine, and spermine are closely associated with cellular growth processes. We examined polyamine levels and the activity of their first rate-limiting enzyme, ornithine decarboxylase (ODC), in stereotactically induced experimental gliomas of the rat brain 1 and 2 weeks after implantation. Regional ODC activity and polyamine levels were determined in the tumor and in the ipsi- and contralateral striatum, white matter, and cerebral cortex. In the tumor, both ODC activity and polyamine levels markedly increased with progressive tumor growth, as compared to those in the white matter of the opposite hemisphere. In the peritumoral brain tissue, ODC activity did not change, but there was a marked increase of putrescine and, to a lesser degree, of spermidine and spermine almost throughout the whole ipsilateral hemisphere. ODC activity, therefore, seems to be a reliable marker of neoplastic growth in the brain, which may be of use for new clinical concepts of the diagnosis and therapy of brain tumors. The more diffuse distribution of polyamines, however, may be associated with the formation and spreading of edema, which would explain some of the biological effects of tumors on distant brain tissue.

Measurements of CSF biochemical tumor markers in patients with meningeal carcinomatosis and brain tumors

CSF beta-glucuronidase, polyamines and carcinoembryonic antigen (CEA) were analyzed in 16 patients with meningeal carcinomatosis from solid tumor in systemic organs, 27 with benign brain lesions, 18 with primary brain tumors, 14 with metastatic brain tumors and 5 with leptomeningeal dissemination of other malignant diseases. Beta-glucuronidase levels in all cases of meningeal carcinomatosis, meningeal gliomatosis and meningeal lymphoma were higher than 100 micrograms/dl/hr; on the other hand, levels in all cases of benign brain lesions were below 100 micrograms/dl/hr. Levels of beta-glucuronidase and polyamines were not high in the cases with positive cytology after tumor resection. Polyamine levels were below 0.05 nmol/ml in all cases after resection of the metastatic brain tumor. Cystic fluid of malignant tumors showed high levels of beta-glucuronidase and polyamines. On the other hand, the levels of polyamines in the cystic fluid of benign tumor were low, although the levels of beta-glucuronidase were high. Some cases of meningeal carcinomatosis with high levels of serum CEA did not show high levels of CSF CEA. For metastatic brain tumors, the cases with intraparenchymal tumors, especially with dural attachment showed high levels of beta-glucuronidase and CEA preoperatively, but they returned to normal after surgery. In cases of meningeal carcinomatosis treated by intrathecal chemotherapy with methotrexate (MTX) and cytosine arabinoside (Ara-C), CSF beta-glucuronidase reflected the neurological status better than the cell count decreased rapidly following chemotherapy and beta-glucuronidase was considered as a useful CSF marker in cases of meningeal carcinomatosis to monitor the course of the disease. The same situation was observed in CSF CEA and CEA was also considered as a useful marker when CEA levels in CSF are higher than those in serum.

Aldehyde dehydrogenase activity in xenografted human brain tumor in nude mice. Preliminary results in human glioma biopsies

ALDH activity measured fluorimetrically using a high concentration of aliphatic aldehyde as substrate was studied in human glioblastomas grafted in nude mice. Compared with normal brain, ALDH activity is significantly increased in malignant glioma tissue, especially in the cytosolic subcellular fraction. Correlatively, in comparison with normal brain tissue, MDA levels were significantly reduced in whole homogenates and in cytosolic fractions of xenografted glioblastoma tissue. Preliminary results concerning human malignant glioma biopsies are in good agreement with our experimental data. In view of previous works, these results suggest a relationship between alterations in ALDH iso-enzymes activities and cytosolic aldehyde concentrations with respect to normal or tumoral cell growth.

Polyamine levels in red blood cells from patient groups of different sex and age

Interpretation of polyamine levels found in the tissues and red blood cells of tumour patients has been plagued by the wide variations seen in the concentrations when estimated in groups of either tumour or control patients. To ascertain whether the patient's age or sex were contributing factors, red blood cell polyamine concentrations of 117 control patients were examined by high-performance liquid chromatography. Concentrations of spermidine were consistently higher than those of spermine. Also, regression analysis showed that spermidine and spermine levels tended to change with age and sex, though these trends were statistically non-significant.

Red blood cell polyamines as a diagnostic indicator of glioma presence and recurrence

Red blood cell (RBC) polyamines, spermine and spermidine have been assayed from 103 patients with confirmed intracranial tumours and 87 controls. For spermine the test had a specificity of 97% and a sensitivity of 30% in preoperative patients, increasing to 40% in glioma patients. Tumour recurrence in postoperative patients gave a sensitivity of 48% increasing to 60% in glioma groups. For initial tumour presentation, therefore, this test is suggestive, though not unequivocal, of tumour presence. Its major role probably lies in monitoring the progress of the patient and its major importance in the detection of tumour recurrence.

Red blood cell polyamines in brain tumour patients

Red blood cell polyamine levels have been determined in patients with various histologically confirmed brain tumours. Increased spermine and spermidine levels were found in most patients with perifocal oedema demonstrated by CT; no correlation was found to other CT variables, nor to tumour localization. Polyamine levels increased during the clinical course coincident with tumour activity and decreased in response to surgery and radiotherapy. The response to chemotherapy involved a change in the relationship between spermine and spermidine levels. Our results underline the significance of regular polyamine level estimation during the management of patients with brain tumours.

Determination of polyamines and metabolites in cerebrospinal fluid by isotope dilution mass fragmentography, and a clinical application

Capillary gas chromatography and mass fragmentography was used to determine simultaneously 1,3-diaminopropane, putrescine, cadaverine, spermidine, spermine, isoputreanine and putreanine in cerebrospinal fluid. After addition of deuterium labelled analogs and acid hydrolysis, the compounds were isolated by adsorption onto silica and converted into their N-heptafluorobutyryl-methylesters. Quality control data and an application of the method are given. A patient harbouring an astrocytoma was monitored during chemotherapeutic treatment.

Evolution of red blood cell polyamine levels in partially hepatectomized rat

Erythrocyte levels of polyamines, especially of spermidine are greatly elevated during the course of liver regeneration. In contrast to putrescine and spermine levels, from the tenth hour to the fourth week after partial hepatectomy, correlation has been observed between the elevation of liver and erythrocyte spermidine concentrations. Substituting drinking water with 2% alpha difluoromethylornithine (alpha-DFMO) commencing 48 hr prior to partial hepatectomy and continuing until death, though ineffective in inhibition of liver [3H]-thymidine incorporation, prevented the rise in hepatic putrescine concentrations (without modifying those of spermidine and spermine) and correlatively decreased red blood cell (RBC) spermidine levels. Thus, an excess of liver spermidine produced from an excess of newly synthetized putrescine could be released in blood and taken up by erythrocytes, especially as affinity of RBC for spermidine is at least 30 fold higher than that for putrescine. In vivo the spermidine half-life in RBC was estimated to be 2.5-3.0 hr, which could explain the elevation of erythrocyte and liver spermidine levels. The elevation of erythrocyte spermidine concentration is not correlated to that of the regenerating liver weight but dependent on the extent of partial hepatectomy. The elevation of erythrocyte spermidine concentrations, which appeared to be linked to the cellular proliferating activity, could contribute to determine intratumoral proliferation in cancerous patients.

Evaluation of polyamine levels in cerebrospinal fluid of children with brain tumors

Cerebrospinal fluid (CSF) polyamine levels were analyzed retrospectively in 21 pediatric patients with different types of intracranial malignant tumors to determine the benefit of following these markers during the clinical management of brain tumors. The tumors included 16 medulloblastomas and 1 each of germinoma, ependymoma, primitive neuroectodermal tumor, astrocytoma, and malignant teratoma. The clinical course of each patient was followed by neurologic examination, cranial computed tomography, CSF cell count, and cytology after cytocentrifugation. The correlation of CSF putrescine and spermidine levels with the clinical course of the brain tumors was analyzed. The following results were obtained: (1) A significant increase in CSF putrescine levels was observed in children with medulloblastoma when there was recurrent or metastatic disease in the sites close to the CSF pathway compared with the children whose disease status was stable after successful treatment (P less than 0.005). (2) The increase of CSF putrescine levels was the earliest predictor of recurrence or metastasis near the CSF pathway. (3) In tumors other than medulloblastoma, the levels of polyamines were not predictive of disease activity with the possible exception of germinoma. (4) Spermidine levels in the CSF were of limited clinical importance for patients with brain tumors. CSF putrescine levels may be the earliest and most sensitive quantitative marker of the progression of medulloblastoma, and their evaluation should be included in the diagnostic work-up and follow-up examination of children with medulloblastoma.

Effect of difluoromethylornithine on the antiglioma therapeutic efficacy of intra-arterial BCNU

In an attempt to improve glioma management, an animal model was developed to evaluate the therapeutic efficacy of intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Furthermore, the model was used to study the antitumor activity of D,L-alpha-difluoromethylornithine (DFMO), a polyamine-biosynthesis inhibitor, used both as a single agent and in combination with intra-arterial BCNU. An N-methylnitrosourea-induced gliosarcoma (T9) was transplanted stereotaxically into the right caudate nucleus of male Fischer 344 rats. Animals receiving a single low-dose (5 mg/kg) intracarotid injection of BCNU 9 days following tumor implantation had a 57% increase in life span compared with untreated control rats (p less than 0.001). Intracarotid drug delivery was more effective than systemic (intraperitoneal) administration of the same dose of BCNU. When given as a single agent, DFMO demonstrated dose-dependent effectiveness. As part of a combined regimen, DFMO enhanced the antitumor therapeutic activity of both systemic (intraperitoneal) and intra-arterial BCNU. Survival times of animals receiving combined DFMO and intra-arterial BCNU were almost double those of untreated controls, and were significantly better than survival times of animals receiving combined DFMO and intraperitoneal BCNU. These findings suggest methods to optimize current clinical chemotherapy for glioma.

Cerebrospinal fluid polyamines: biochemical markers of malignant childhood brain tumors

The clinical value of cerebrospinal fluid (CSF) polyamine determinations in childhood medulloblastoma has been suggested. We performed 72 CSF polyamine determinations in 35 children with primary brain tumors. Spermine values were normal and spermidine values were inconsistently elevated. CSF putrescine values, however, were consistently elevated in patients with histologically malignant brain tumors: medulloblastoma, ependymoma, pineal germ cell tumors, primitive neuroectodermal tumors, and brainstem gliomas. Children with supratentorial astrocytomas had normal CSF polyamine values. CSF putrescine values were closely correlated with clinical state, with the highest concentrations identified in patients with widely disseminated recurrent disease. We found CSF putrescine to be a sensitive indicator of active disease in childhood malignant brain tumors. Further investigation is warranted into the predictive value of CSF polyamines in determining tumor relapse before clinical or other diagnostic studies reveal recurrent disease.

Putrescine metabolism in human brain tumors

The metabolism of the polyamines, putrescine, spermidine and spermine, was studied in human brain and brain tumors. Samples of brain and tumors were incubated with 3H-putrescine and the amounts of labeled polyamines were measured. The amount of putrescine conversion was found to be greater in tumors that in normal brain samples. Furthermore, the metabolism of putrescine in brain tumors was related to tumor type and appeared to correlate with the degree of malignancy. The significance of these findings with regard to positron emission tomographic scanning and therapy of patients with malignant gliomas is discussed.

Diagnostic value of erythrocyte-free polyamines and histaminemia in malignant hepatic tumors and in liver cirrhosis

The present study tries to evaluate the diagnosit value in malignant hepatic tumors of polyamines, of which the relationship with cellular kinetics is known, and histamine, of which catabolism follows a similar pathway. One hundred and fifty six patients were studied: 53 with malignant liver tumors (27 primary, 26 metastatic) and 103 with non-tumoral liver diseases of which 65 were cirrhotic and 38 non-cirrhotic. Erythrocyte polyamines (spermidine and spermine) and histamine levels were assayed. The results indicate the following. 1. Polyamine levels were significantly increased (a) in cirrhotic patients, not only when compared with controls (p less than 10(-8)), but also when compared with the non-cirrhotic patients (p less than 10(-7)); (b) in primary malignant hepatic tumors (p less than 10(-3)). 2. Histamine was significantly increased (a) in the non-tumoral liver diseases (p less than 10(-4)), but with no difference between cirrhotic and non-cirrhotic patients; (b) in the secondary malignant tumor patients, histamine levels were lower than in primary tumor patients (p less than 0.04). 3. There was no correlation, in all groups studied, between polyamine and histamine levels. These results suggest the following practical implications. 1. For non-tumor liver diseases, appreciably increased polyamine levels may represent a further argument favoring a cirrhotic condition. 2. In diagnosing hepatic scintigraphic defects, increased polyamine levels would suggest a primary malignant hepatic tumor; low histamine levels are more in favor of a secondary malignant hepatic process.