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)

N-Phosphonacetyl-L-aspartic acid (PALA) is new synthetic antimetabolite which inhibits de novo pyrimidine biosynthesis. Its significant activity against Lewis lung carcinoma, B16 melanoma, and glioma 26 suggested that it might be useful in the treatment of human solid tumors. Phase I trials revealed that dose-limiting toxicity included skin reactions, diarrhea, and stomatitis. Pharmacologic studies demonstrated rapid renal excretion of more than 70% of the unmetabolized drug in 24 h. Peak plasma levels correlated with dose of PALA administered. Partial responses to PALA were seen in one patient with melanoma, one with chondrosarcoma, and one with colon carcinoma. The potential for PALA's use in combination chemotherapy, particularly with 5-fluorouracil, is discussed.
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PMID:An overview of the clinical pharmacology of N-phosphonacetyl-L-aspartate (PALA), a new antimetabolite. 744 50

Retroviral vector is often used for gene therapy of malignant tumors. The main characteristic of this vector is that it integrates only into the genes of dividing and proliferating cells. Glioma cells proliferate actively, while surrounding normal brain cells rarely divide. Thus, we can expect the recombinant retrovirus modified to express cytotoxic genes to kill glioma cells selectively. However, this characteristic of specific toxicity to the dividing cells is also observed in many chemotherapeutic agents, and it is well known that they cause severe side effects, such as bone marrow suppression or diarrhea caused by simultaneous toxicity of the drugs to proliferating bone marrow cells or intestinal epithelial cells, respectively. We have cloned many genes which are specifically expressed in brain, and identified their promoter regions conferring tissue-specific expression. If we use the brain-specific promoters to regulate the expression of the toxic genes, these genes may not be expressed in the myeloid cells or intestinal epithelial cells, even if they were infected with the retrovirus. Therefore, we searched for brain-specific promoters which are also active in glioma cells to kill glioma cells specifically. Then, MBP promoter showed the strongest promoter activity in mouse glioma cells. These mouse glioma cells transduced with retrovirus containing the MBP promoter directing the herpes simplex virus type 1 thymidine kinase (HTK) gene were extremely sensitive to ganciclovir, even when transduced with the MBP promoter-HTK gene-containing retrovirus. And we could get complete remission in the mouse brain tumor models, which were transfected HTK genes in more than 25% glioma cells, with ganciclovir.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Selective gene therapy of malignant gliomas using brain-specific promoters: its efficacy and basic investigations]. 752 68

Twenty-two patients with supratentorial malignant gliomas were treated postoperatively with concurrent intracarotid chemotherapy and radiation therapy. There were seven women and 15 men with a median age of 56 years (range, 22-69) and median performance status (Karnofsky score) of 70 (range, 40-90). In all except two cases, histologic studies confirmed malignant glioma. All patients were irradiated with a cobalt 60 equipment. They should have received 45 Gy to the whole brain plus a 15-Gy coned-down boost to the tumor area. Chemotherapy consisted of cisplatin infusion at a dose of 60 mg/m2 on days 2, 22, and 42. Treatment was interrupted in two patients because of progressive disease and voluntary withdrawal in one patient each. In all, 63 courses of cisplatin infusion were administered, all at full dose. Two patients achieved a partial response, and nine had stable disease. Toxicities included nausea/vomiting in nine patients (41%) and transient hemiparesis, confusion, diarrhea, and thrombophlebitis in one patient each. Median time to progression was 26 weeks (range, 4-226+), and median survival was 58 weeks (range, 14-226+). In conclusion, the present study suggests that intracarotid cisplatin administered concurrently with radiation does not improve the therapeutic index in malignant gliomas.
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PMID:Concurrent radiation and intracarotid cisplatin infusion in malignant gliomas: a feasibility study. 912 86

Pre-clinical data and adult experience suggests that topoisomerase targeted anti-cancer agents may be highly schedule dependent, and efficacy may improve with prolonged exposure. To investigate this hypothesis, 28 children with recurrent brain and solid tumors were enrolled in a phase II study of oral etoposide (ETP). Patients were prescribed ETP at 50 mg/m2/ day for 21 consecutive days. Courses were repeated every 28 days pending bone marrow recovery. Evaluation of response was initially performed after 8 weeks and then every 12 weeks either by CT or MRI. Three of 4 patients with PNET (primitive neuroectodermal tumor)/medulloblastora achieved a partial response (PR). Two of 5 with ependymoma responded, one with a complete response and one with a PR. Toxicity was manageable with only 1 admission for fever and neutropenia in 120 cycles of therapy. Five patients had grade 3 or 4 neutropenia. One had grade 4 thrombocytopenia and one grade 2 mucositis and withdrew as a result. One patient had grade 2 diarrhea. Two patients who achieved a PR had received ETP as part of prior combination chemotherapy regimens. Daily oral etoposide is active in recurrent PNET/medulloblastoma and ependymoma. Toxicity is manageable and rarely requires intervention. Daily oral etoposide in combination with crosslinking agents should be considered in future phase III trials. Determination of activity in glioma and solid tumors is not complete.
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PMID:Phase II study of daily oral etoposide in children with recurrent brain tumors and other solid tumors. 914 2

Lovastatin, an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (the major regulatory enzyme of the mevalonate pathway of cholesterol synthesis), displays antitumor activity in experimental models. We therefore conducted a Phase I trial to characterize the tolerability of lovastatin administered at progressively higher doses to cancer patients. From January 1992 to July 1994, 88 patients with solid tumors (median age, 57 +/- 14 years) were treated p.o. with 7-day courses of lovastatin given monthly at doses ranging from 2 to 45 mg/kg/day. The inhibitory effects of lovastatin were monitored through serum concentrations of cholesterol and ubiquinone, two end products of the mevalonate pathway. Concentrations of lovastatin and its active metabolites were also determined, by bioassay, in the serum of selected patients. Cyclical treatment with lovastatin markedly inhibited the mevalonate pathway, evidenced by reductions in both cholesterol and ubiquinone concentrations, by up to 43 and 49% of pretreatment values, respectively. The effect was transient, however, and its magnitude appeared to be dose independent. Drug concentrations reached up to 3.9 micrometer and were in the range associated with antiproliferative activity in vitro. Myopathy was the dose-limiting toxicity. Other toxicities included nausea, diarrhea, and fatigue. Treatment with ubiquinone was associated with reversal of lovastatin-induced myopathy, and its prophylactic administration prevented the development of this toxicity in a cohort of 56 patients. One minor response was documented in a patient with recurrent high-grade glioma. Lovastatin given p.o. at a dose of 25 mg/kg daily for 7 consecutive days is well tolerated. The occurrence of myopathy, the dose-limiting toxicity, can be prevented by ubiquinone supplementation. To improve on the transient inhibitory activity of this dosing regimen on the mevalonate pathway, alternative schedules based on uninterrupted administration of lovastatin should also be studied.
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PMID:Phase I study of lovastatin, an inhibitor of the mevalonate pathway, in patients with cancer. 981 94

Although the efficacy of the nitrosourea-based combination chemotherapy procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosurea, and vincristine (PCV) has been previously demonstrated in the setting of anaplastic/intermediate-grade gliomas, the benefit for glioblastoma patients remains unproven. In the current study, we sought to determine whether the addition of alpha-difluoromethylornithine (eflornithine), an inhibitor of ornithine decarboxylase, which has shown encouraging results in the setting of recurrent glioma patients, to a nitrosourea-based therapy (PCV) would constitute a more effective adjuvant therapy in the treatment of glioblastoma multiforme patients in the postradiation therapy setting. Following conventional radiation therapy, 272 glioblastoma (GBM) patients were randomized to receive either alpha-difluoromethylornithine-PCV (DFMO-PCV; 134 patients) or PCV alone (138 patients), with survival and time to tumor progression being the primary endpoints. The starting dosage of DFMO was 3.0 g/m2 p.o. q8h for 14 days before and after treatment with N-(2-chloroethyl)-N-cyclohexyl-N-nitrosurea; PCV was administered as previously described1. Clinical and radiological (Gadolinium-enhanced MRI) follow-ups were nominally at the end of each 6 or 8 week cycle (PCV at 6 weeks; DFMO-PCV at 8 weeks). Laboratory evaluations for hematologic and other adverse effects were at 2 week intervals. There was no difference in median survival or median time-to-tumor progression between the two treatment groups, as measured from day of commencement of postradiotherapy chemotherapy [MS (months): DFMO-PCV, 10.5; Overall survival, as measured from time of tumor diagnosis at first surgery, was 13.3 and 14.2 months at the median and 6.2 and 8.7% at 5 years, respectively, for the DFMO-PCV and PCV arms. The treatment effect was unchanged after adjustment for age, performance status (KPS), extent of surgery, and other factors using the multivariate Cox proportional hazard model. Adverse effects associated with DFMO consisted of gastrointestinal (diarrhea nausea/vomiting), cytopenias, and minimal ototoxicity (limited to tinnitus) at the dose range tested. The addition of DFMO to the nitrosourea-based PCV regimen in this phase III study demonstrated no additional benefit in glioblastoma patients, underscoring the resistance of glioblastoma multiforme tumors to alkylating agents. For patients with anaplastic (intermediate grade) gliomas, in which the previously demonstrated benefit of post-radiation chemotherapy is more substantial, the evaluation of DFMO-PCV vs. PCV is still ongoing and hopefully will yield more encouraging results.
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PMID:Phase III randomized study of postradiotherapy chemotherapy with alpha-difluoromethylornithine-procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosurea, vincristine (DFMO-PCV) versus PCV for glioblastoma multiforme. 1105 Dec 33

A Phase I trial of irinotecan was performed to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs), and the incidence and severity of other toxicities in children with refractory solid tumors. Thirty-five children received 146 courses of irinotecan administered as a 60-min i.v. infusion, daily for 5 days, every 21 days, after premedication with dexamethasone and ondansetron. Doses ranged from 30 mg/m2 to 65 mg/m2. An MTD was defined in heavily pretreated and less-heavily pretreated (i.e., two prior chemotherapy regimens, no prior bone marrow transplantation, and no radiation to the spine, skull, ribs, or pelvic bones) patients. Myelosuppression was the primary DLT in heavily pretreated patients, and diarrhea was the DLT in less-heavily pretreated patients. The MTD in the heavily pretreated patient group was 39 mg/m2, and the MTD in the less-heavily pretreated patients was 50 mg/m2. Non-dose-limiting diarrhea that was well controlled and of brief duration was observed in approximately 75% of patients. A partial response was observed in one patient with neuroblastoma, and in one patient with hepatocellular carcinoma. Stable disease (4-20 cycles) was observed in seven patients with a variety of malignancies including neuroblastoma, pineoblastoma, glioblastoma, brainstem glioma, osteosarcoma, hepatoblastoma, and a central nervous system rhabdoid tumor. In conclusion, the recommended Phase II dose of irinotecan administered as a 60-min i.v. infusion daily for 5 days, every 21 days, is 39 mg/m2 in heavily treated and 50 mg/m2 in less-heavily treated children with solid tumors.
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PMID:A phase I study of irinotecan in pediatric patients: a pediatric oncology group study. 1120 14

The fruit hull of mangosteen, Garcinia mangostana L., has been used for many years as a medicine for treatment of skin infection, wounds, and diarrhea in Southeast Asia. In the present study, we examined the effect of gamma-mangostin, a tetraoxygenated diprenylated xanthone contained in mangosteen, on arachidonic acid (AA) cascade in C6 rat glioma cells. gamma-Mangostin had a potent inhibitory activity of prostaglandin E2 (PGE2) release induced by A23187, a Ca2+ ionophore. The inhibition was concentration-dependent, with the IC50 value of about 5 microM. gamma-Mangostin had no inhibitory effect on A23187-induced phosphorylation of p42/p44 extracellular signal regulated kinase/mitogen-activated protein kinase or on the liberation of [14C]-AA from the cells labeled with [14C]-AA. However, gamma-mangostin concentration-dependently inhibited the conversion of AA to PGE2 in microsomal preparations, showing its possible inhibition of cyclooxygenase (COX). In enzyme assay in vitro, gamma-mangostin inhibited the activities of both constitutive COX (COX-1) and inducible COX (COX-2) in a concentration-dependent manner, with the IC50 values of about 0.8 and 2 microM, respectively. Lineweaver-Burk plot analysis indicated that gamma-mangostin competitively inhibited the activities of both COX-1 and -2. This study is a first demonstration that gamma-mangostin, a xanthone derivative, directly inhibits COX activity.
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PMID:Inhibition of cyclooxygenase and prostaglandin E2 synthesis by gamma-mangostin, a xanthone derivative in mangosteen, in C6 rat glioma cells. 1175 76

Other than nitrosoureas (carmustine and lomustine) and temozolomide, no agents have consistently demonstrated clinically meaningful benefits for patients with gliomas. The active metabolite of irinotecan, 7-ethyl-10-hydroxy camptothecin (SN-38), exhibited promising antitumor effects in preclinical glioma models. Clinical trials using weekly or every 3 weeks dosing of irinotecan have been completed. Toxicity consisted primarily of mild to moderate neutropenia and diarrhea with both schedules, with occasional severe toxicity including one death from neutropenia and infection. Preliminary analyses have suggested imaging responses in 10-15% of patients. Preclinical models and our understanding of the mechanism of action suggest that irinotecan may sensitize glioma cells to the cytotoxic actions of radiation therapy and alkylating agents; clinical trials designed to assess the therapeutic benefit of combination therapy currently are in progress. There is substantial clinical evidence that the concurrent administration of irinotecan with certain anticonvulsants produces reduced exposure to SN-38. In the absence of anticonvulsants, there is also substantial interpatient variability in drug exposure, perhaps reflecting inherited differences in drug metabolism. Finally several mechanisms of tumor cell resistance to irinotecan have been hypothesized, but the clinical significance of these observations has not been confirmed. Correlative studies to address these pharmacokinetic, pharmacogenetic, and drug resistance questions are ongoing.
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PMID:Irinotecan in the treatment of glioma patients: current and future studies of the North Central Cancer Treatment Group. 1271 56

The primary objective of this study was to determine the proportion of patients exhibiting a radiographic response in a cohort of patients with recurrent malignant glioma who were treated with irinotecan. Secondary objectives were to determine progression-free survival, overall survival, and toxicity. The trial was terminated after the first 18 patients were enrolled in this multicenter, 2-stage, phase 2 study. Twelve patients received concurrent enzyme-inducing antiepileptic drugs, and 6 did not. Each cycle consisted of a 90-min i.v. infusion of irinotecan every week for 4 consecutive weeks, followed by 2 weeks off. One patient had a complete response, 5 patients had stable disease, 5 patients had radiographic progression, 6 patients were removed from the study because of toxicity, and 1 patient refused further therapy and was removed from the study. The response rate in this study was 6% (1/18), and 28% (5/18) of these patients progressed while receiving irinotecan. Dose-limiting toxicities consisted of diarrhea in 5 patients, neutropenia in 1 patient, infection in 1 patient, and respiratory failure in 1 patient. Irinotecan had minimal efficacy in this cohort of 18 patients with recurrent malignant glioma. Toxicity was significant but similar to that reported in other patient populations.
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PMID:Phase 2 study of weekly irinotecan in adults with recurrent malignant glioma: final report of NABTT 97-11. 1476 36


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