Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, MAbs to the 'conventional' gangliosides expressed by human gliomas were generated and used to detect ganglioside species previously unisolated or defined in normal adult CNS tissue. Despite the marked phenotypic and genotypic heterogeneity shown by glioma cell lines (Bigner et al., 1981), the ganglioside phenotype of these cell lines is remarkably consistent qualitatively, if not quantitatively, in the ganglioside species expressed (Table V). The majority of cell lines and tumor samples express GM2, GD2 and GD3; this does not provide a diagnostic advantage (Vick et al., 1992). Nevertheless, as the relative amounts of these gangliosides in tumor as compared with normal adult CNS tissue is considerable, such reagents might be considered in compartmental immunotherapeutic approaches. Since GD2 and GD3 have been determined to mediate tumoricidal activity with human effector cells via specific antiganglioside epitope MAbs (Thurin et al., 1987; Kushner and Cheung, 1991; Barker et al., 1991; Reisfeld, 1993), cell-mediated approaches, as well as targeted immunoglobulin therapies, are also possible. The prospect of a more targeted approach with little or no effect on normal CNS tissue is now possible via the 'oncofetal' epitopes characteristic of 3'-isoLM1 and 3',6'-isoLD1. Several factors recommend the use of these moieties for compartmental immunotherapy; the inability to detect them within the adult CNS; the relatively high frequency of expression of 3'-isoLM1 and 3',6'-isoLD1, especially in human tumor samples (50-100%, depending upon the series and assay); and the existence of specific MAbs reactive with these epitopes. Current technology is being applied to these MAbs to transfer the specific recognition capacity of existing murine MAbs into various human framework structures of any desired immunoglobulin class, and thereby, biologic function. The variety of effector functions, the stability in affinity, labeling capacity, and the exquisite sensitivity of these MAbs for these glioma-distinctive epitopes is an exciting and promising approach for immunotherapy of human CNS tumors.
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PMID:Detection of glioma-associated gangliosides GM2, GD2, GD3, 3'-isoLM1 3',6'-isoLD1 in central nervous system tumors in vitro and in vivo using epitope-defined monoclonal antibodies. 751 92

A case-control study on risk factors for cerebral tumors was conducted on an adult Italian population by the four Neurosurgical Departments of the Veneto Region, i.e. Padua, Treviso, Verona and Vicenza. The study recruited 195 cases of histologically-confirmed cerebral glioma. One hospital control was selected for each case. Cases and controls were matched for age, sex, data of hospitalization and residence. Information on both cases and controls was obtained from a relative. Uninvolved interviewers administered a structured questionnaire including items on the subject's education, occupation, lifestyle, medical history, exposure to radiation for diagnosis or therapy, head trauma and blood group and the medical history of family members. The series of cerebral tumors was first considered as an indistinct set: none of the risk factors examined showed a statistically significant association. A positive association was found with blood group A (OR = 6) when low-grade astrocytomas (n = 41) were considered separately. As for the malignant astrocytomas (n = 132), there was a suggestive but not statistically significant association with the presence of CNS tumors among first- and second-degree relatives (OR = 7.0). On the whole, this study yielded no clear and meaningful association for the various risk factors analyzed.
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PMID:Risk factors for cerebral glioma in adults: a case-control study in an Italian population. 781 5

Southern blot analyses of the 9p-localized type I interferon (IFN) genes in DNAs obtained from malignant glioma cell lines and glial tumor tissue have indicated that homozygous deletions of the IFN-alpha and IFN-beta genes often occur during the development of the highly malignant central nervous system neoplasm, glioblastoma. We have applied a set of markers that span the IFN region on 9p to the analysis of DNAs from 30 human glioma cell lines in order to define the region of homozygous deletion associated with this cancer more precisely. Fourteen of the cell lines revealed either complete (12 cases) or partial (2 cases) homozygous deletions of the IFN-alpha gene cluster; no instances of homozygous deletions were observed that did not involve the IFN-alpha region. Genomic DNA identified by the markers nearest to and flanking the IFN-alpha genes were retained in 5 of the cases with homozygous deletions. Consequently, these results limit the extent of homozygous deletions in glioma cell lines to a small region of 9p21-p22 that includes most of the type I IFN locus.
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PMID:Localization of chromosome 9p homozygous deletions in glioma cell lines with markers constituting a continuous linkage group. 833 74

Despite innovations in imaging, surgery, and radiation therapy, local failure remains the principle clinical problem in most CNS malignancies. To date, chemotherapy has not major impact in the treatment of most adult CNS tumors. The inroads made by chemotherapy in pediatric CNS malignancies suggest that novel drugs, or drug combinations, may improve therapy. Topoisomerase I (Topo I) inhibitors are a relatively new group of chemotherapy drugs with a novel mechanism of action. Drugs in this group currently undergoing clinical trials are the Camptothecin analogues Topotecan, CPT-11, and 9-aminocamptothecin. There is substantial preclinical and some clinical evidence to suggest that these drugs could be useful in the treatment of CNS malignancies. Preclinical studies with the water soluble Topo I inhibitor, Topotecan, demonstrate antineoplastic activity in a variety of CNS malignancies. In addition, Topotecan has good CNS penetration in primates, and recent preliminary phase I and II clinical trials of Topotecan in pediatric and adult CNS malignancies have been promising. In this paper, we describe the unique mechanism of action, antineoplastic activity, and radiosensitizing properties of Topo I inhibitors. We present the first report demonstrating potentiation of radiation lethality by Topotecan in a human glioma (D54) cell line. The dose enhancement ratio was 3.2 at 10% survival. Thus, there is evidence to suggest that Topo I inhibitors may be beneficial in the treatment of CNS neoplasms on the basis of their antineoplastic activity alone, as well as their radiosensitizing effects. Two clinical trials which utilize concurrent Topotecan and radiation in the treatment of pediatric and adult CNS malignancies are discussed.
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PMID:The potential of topoisomerase I inhibitors in the treatment of CNS malignancies: report of a synergistic effect between topotecan and radiation. 886 97

Detection and characterization of distinct central nervous system (CNS) tumor cell types is clinically important since distinct tumor types are associated with different prognoses and treatments. However, there is currently a lack of markers to identify certain glioma types and insufficient understanding as to which cells give rise to different glioma cell types. In the present study, biopsy specimens from human brain tumors were analyzed for expression of Myelin Transcription Factor 1 (MYT1) to explore the extent to which glioma cells reflect characteristic expression of MYT1 in developing glial progenitor cells. Immunostaining with an antibody against MYT1 revealed widespread immunoreactivity that was most prominent in high-grade oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas as well as in a dysembryoplastic neuroepithelial tumor. MYT1 immunoreactivity in tumor regions generally correlated with the prevalence of cells exhibiting nuclear immunolabeling with an antibody against Ki-67, suggesting an association of MYT1 with cell proliferation that was also observed in normal adult human and rat brain in the germinal subependymal zone. The MYT1 immunoreactivity was frequently nuclear, appearing as dotted or punctate, but in some cases it was localized to the cytoplasm. In combination with histopathological studies and analysis of Ki-67 immunoreactivity, examination of MYT1 immunolabeling may provide additional information to aid in the detection and diagnosis of CNS tumors.
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PMID:High-grade human brain tumors exhibit increased expression of myelin transcription factor 1 (MYT1), a zinc finger DNA-binding protein. 921 Aug 73

Nitrosoureas are among the most widely used agents used in the treatment of malignant gliomas. Here, the activity of 2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) was compared with that of 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), in vivo against s.c. implanted SF-295 and U-251 central nervous system (CNS) tumor xenografts. When given i.v., q4d for 3 doses, to athymic mice bearing s.c. SF-295 tumors, SarCNU, at an optimum of 167 mg/kg/dose, produced 9 tumor-free animals of 10 total animals, 1 regression, and no evidence of overt toxicity (> or =20% body weight loss). With a similar dosing schedule, BCNU produced no tumor-free animals, six regressions, and one drug-related death at its optimum of 30 mg/kg/dose. Furthermore, SarCNU retained high antitumor activity at two lower dose levels, 66 and 45% of the optimal dose, whereas BCNU demonstrated a progressive loss of antitumor activity at lower doses. Following p.o. administration, SarCNU similarly demonstrated antitumor activity that was superior to that of BCNU. In the U-251 CNS tumor model, SarCNU yielded six of six tumor-free animals at 80 mg/kg/dose with i.p. administration q.d. for 5 days, starting on day 14, whereas BCNU, at 9 mg/kg/dose, yielded three of six tumor-free mice and one drug-related death. Again, SarCNU resulted in tumor-free animals at 66 and 45% of its optimal dose and was relatively nontoxic, in contrast to BCNU. Results of testing to date indicate that SarCNU is clearly more effective than BCNU against the human CNS tumors SF-295 and U-251 in vivo. These results encourage the initiation of clinical trials for SarCNU, in an effort to improve therapeutic approaches to glioma, but clinical trials must determine whether superiority of SarCNU in preclinical models can be extrapolated to patients.
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PMID:2-Chloroethyl-3-sarcosinamide-1-nitrosourea, a novel chloroethylnitrosourea analogue with enhanced antitumor activity against human glioma xenografts. 930 67

Imagery is the only possibility of early glioma diagnosis. Both the gravity of the evolution and the bad prognostic, through all CNS tumors, justify the necessity to asses new techniques in order to improve glioma imagery. From this point of view, cerebral tomoscintigraphy has developed, its usefulness depending highly on the radiotracer tumoral specificity. One of these tracers, 99mTc MIBI, has been found to be uptake in glioma malignant cells, in relation with their viability and even malignity. In our study, -14 cerebral tomoscintigraphies have been realized on patients with glioma (initial or recurrent tumor), after 20 mCi 99mTc MIBI i.v. doses. The results are in correlation with the histologic glioma grade: high grade astrocytoma has positive images, but low grade astrocytoma doesn't. In conclusion 99mTc MIBI glioma tomoscintigraphies can be useful in their initial or recurrent diagnosis; the uptake tracer intensity being correlated with the histologic tumoral pattern, 99mTc MIBI SPECT could make possible a better localization of highest malignity tumoral points, in further biopsies.
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PMID:[The value of scintigraphic imaging with 99mTc-MIBI for the diagnosis of gliomas]. 945 54

The clotting factor XIIIa (FXIIIa) has been shown to be present both in tumor cells and in tumor-associated macrophages of different neoplasms such as Hodgkin's disease, giant cell tumor of bone, malignant fibrous histiocytoma, meningeal tumors, and hemangiopericytoma. The biological significance of these findings, however, are still unclear. This study investigates the immunohistochemical distribution of FXIIIa in 186 tumors of the central nervous system (CNS) in order to evaluate its possible diagnostic or prognostic significance in neuro-oncology. High-grade gliomas such as glioblastoma, gliosarcoma, astrocytoma (grade III WHO), and ependymoma (III) as well as meningiomas and meningeal hemangiopericytomas consistently contained factor XIIIa-positive cells, whereas low-grade glial tumors did not do so. One desmoplastic medulloblastoma and one anaplastic schwannoma also showed FXIIIa-positive cells. With the exception of hemangiopericytomas, however, the major source of FXIIIa expression in all these tumors consisted of a subpopulation of tumor-associated macrophages, the exact role of which still remains unclear. Because of its non-discriminatory staining in a wide variety of CNS tumors, the differential diagnostic contribution of FXIIIa in neuro-oncology seems to be limited.
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PMID:Factor XIIIa-immunoreactivity in tumors of the central nervous system. 956 29

Chloroethylnitrosoureas (CENUs) are commonly used in the treatment of pediatric and adult central nervous system (CNS) tumors. The antitumor activity of CENUs has been hypothesized to be due to an alkylation occurring at the O6-position of guanine in DNA. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is responsible for the repair of these potentially cytotoxic lesions and may underlie tumor resistance to CENUs. The current study is the largest report of MGMT levels among newly diagnosed pediatric CNS tumors and the only study that has quantitated MGMT by both biochemical and Western immunoblot assays. Our results show a good correlation between the two methods (r = 0.66). Medulloblastoma/primitive neuroectodermal tumor and ependymoma had the highest level of MGMT, followed by high-grade glioma and low-grade glioma. These data may provide a guide to the use of CENUs in the treatment of pediatric CNS tumors.
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PMID:O6-Methylguanine-DNA methyltransferase protein levels in pediatric brain tumors. 981 47

Between 1988 and 1997, 28 children have had iodine-125 implants for CNS tumors performed in our institution. Ten had stereotactic implantation in the brain stem region, and nine had the diagnosis of brain stem glioma (8 diffuse pontine, 1 midbrain tumor). Their ages ranged from 1.8 to 12 years. All patients had histological confirmation of malignancy (7 high-grade glioma, 2 low-grade glioma, 1 PNET). Diffuse pontine glioma patients received external beam radiation (50 Gy) followed by a fractionated stereotactic boost of 3 Gyx4 fractions. After 4-6 weeks, patients were reevaluated for stereotactic interstitial I-125 therapy. The planned implant dose was 82.9 Gy to the enhancing tumor (4 cGy per h). Preliminary results indicated that no surgical complications were associated with the catheter placement. Four patients have died (7-9 months from diagnosis) and four patients remain alive (5-38 months from diagnosis, median 10 months). Two autopsies confirmed the presence of progressive glioblastoma multiforme and intralesional necrosis. In one patient who received an implant alone for midbrain LGA, necrosis without tumor was found on biopsy after 36 months. He was successfully treated with hyperbaric oxygen therapy. The implementation of permanent I-125 implants appears to have a role in the management of pediatric CNS malignancy. This study confirms the results of previous reports regarding the safety of stereotactic interstitial brachytherapy in the brain stem. Tumor control for patients with high-grade brain stem glioma remains poor even with high focal radiation doses.
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PMID:Permanent I-125 brain stem implants in children. 984 Mar 81


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