Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0017638 (glioma)
30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was to determine the maximum-tolerated dose, of a pre-targeting three-step (3-S) method employing 90Y-biotin in the locoregional radioimmunotherapy (RIT) of recurrent high grade glioma, and to investigate the antitumor efficacy of this new treatment. Twenty-four patients with recurrent glioma underwent second surgical debulking and implantation of a catheter into the surgical resection cavity (SRC), in order to introduce the radioimmunotherapeutic agents [biotinylated monoclonal antibody (MoAb), avidin and 90Y-biotin]. Eight patients with anaplastic astrocytoma (AA) and 16 patients with glioblastoma (GBM) were injected with biotinylated anti-tenascin MoAb (2 mg), then with avidin (10 mg; 24 h later) and finally 90Y-biotin (18 h later). Each patient received two of these treatments 8-10 weeks apart. The injected activity ranged from 0.555 to 1.110 GBq (15-30 mCi). Dosage was escalated by 0.185 GBq (5 mCi) in four consecutive groups. The treatment was well tolerated without acute side effects up to 0.740 GBq (20 mCi). The maximum tolerated activity was 1.110 GBq (30 mCi) limited by neurological toxicity. None of the patients developed hematologic toxicity. In three patients infection occurred around the catheter. The average absorbed dose to the normal brain was minimal compared with that received at the SRC interface. At first control (after 2 months), partial (PR) and minor (MR) responses were observed in three GBM (1 PR; 2 MR) and three AA patients (1 PR; 2 MR) with an overall objective response rate of 25%. Stable disease (SD) was achieved in seven GBM and five AA patients (50%). There was disease progression in six GBM patients (25%), but in none of the AA patients. At the dosage of 0.7-0.9 GBq per cycle, locoregional 3-S-RIT was safe and produced an objective response in 25% of patients. Based on these encouraging results, phase II studies employing 3-S-RIT soon after first debulking are justified.
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PMID:Pre-targeted locoregional radioimmunotherapy with 90Y-biotin in glioma patients: phase I study and preliminary therapeutic results. 1147 87

We have identified secreted protein acidic and rich in cysteine (SPARC) as a potential glioma invasion-promoting gene. To determine whether SPARC alters the growth, attachment, or migration of gliomas, we have used U87T2 and doxycycline-regulatable SPARC-transfected clones to examine the effects of SPARC on (1) cell growth, (2) cell cycle progression, (3) cell attachment, and (4) cell migration, using growth curves, flow cytometry, attachment, and migration analyses on different brain ECMs, including collagen IV, laminin, fibronectin, vitronectin, hyaluronic acid, and tenascin. Our data indicate that SPARC delays tumor cell growth in the log phase of the growth curve. The clones secreted different levels of SPARC. The clone secreting the lowest level of SPARC was associated with a higher percentage of cells in G2M, whereas the clones secreting the higher levels of SPARC were associated with a greater percentage of cells in G0/G1. In comparison to the parental U87T2 clone, the SPARC-transfected clones demonstrated increased attachment to collagen, laminin, hyaluronic acid, and tenascin, but not to vitronectin or fibronectin. SPARC-transfected clones also demonstrated altered migration on the different extracellular matrix proteins. The modulation of migration, either positive or negative, was associated with changes in the level of secreted SPARC. These data suggest that SPARC may modulate glioma proliferation and invasion by modulating both the growth and migration of glioma cells.
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PMID:SPARC modulates cell growth, attachment and migration of U87 glioma cells on brain extracellular matrix proteins. 1171 67

This work demonstrates the expression of extracellular matrix (ECM) components in a highly infiltrative brain tumor model developed by simple inoculation of spheroids from five human glioma biopsy tissues directly into the brains of immunodeficient rats. Non-invasive tumors derived from one glioblastoma biopsy specimen and two glioma cell lines (D-54MG and U-251MG) were also included in this study. The extent of tumor cell infiltration was studied using a pan-human monoclonal anti-vimentin antibody. The cellular origin for several of these ECM components was identified using human-specific monoclonal antibodies and polyclonal antibodies detecting epitopes from both species. Immunostaining revealed a diffuse parenchymal staining of glioma-produced tenascin, whereas vitronectin was produced mainly by the invading glioma cells. ECM components such as laminin, fibronectin and collagen type IV were most probably produced by the host and were mainly associated with the blood vessels in the tumors. However, some parenchymal staining with regional variations was observed. The expression pattern of these components was different in cell lines tumors as compared to the biopsy specimen tumors. The alpha3 and beta1 integrin subunits were mainly observed in areas of tumor cell invasion in the invasive tumors. In conclusion, the observed staining patterns clarify the cellular origin and indicate the possible biological function of tenascin, vitronectin, laminin, fibronectin and collagen type IV in these highly invasive malignant tumors of glial origin.
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PMID:Expression of extracellular matrix components in a highly infiltrative in vivo glioma model. 1247 61

In the last two decades radioimmunotherapy has been used as an additional treatment option for malignant glioma in several centers. More than 400 patients have been reported, who were treated in the framework of different studies. Most of them received labelled antibodies to tenascin, an extracellular matrix-glycoprotein, which is expressed in high amounts in malignant gliomas. We report side effects and survival time of 46 patients, treated after surgical resection and conventional radiotherapy with intralesionally injected labelled (131-Iodine) antibodies to tenascin. Despite the fact, that many treatments have been performed, little is known about the distribution properties of labelled antibodies after injection in the tumour cavity. For an optimal effect labelled antibodies should be able to reach tumour cells, which have migrated into the surrounding tissue. We investigated the propagation velocity and area of distribution of labelled antibodies and their considerably smaller fragments after the injection in C6-gliomas of Wistar rats. Propagation increased with time and was significantly greater after injection of labelled fragments than after injection of labelled antibodies. According to our results labelled fragments might be better able to reach distant tumour cells in the peritumoural tissue of malignant gliomas than labelled antibodies.
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PMID:Intralesional radioimmunotherapy in the treatment of malignant glioma: clinical and experimental findings. 1453 64

We have obtained encouraging responses in recent Phase I studies evaluating (131)I-labeled human/murine chimeric 81C6 anti-tenascin monoclonal antibody (ch81C6) administered into surgically-created tumor resection cavities in brain tumor patients. However, because the blood clearance is slow, hematologic toxicity has been higher than seen with murine 81C6 (mu81C6). In the current study, a series of paired-label experiments were performed in athymic mice bearing subcutaneous D-245 MG human glioma xenografts to compare the biodistribution of the fragment ch81C6 F(ab')(2) labeled using Iodogen to a) intact ch81C6, b) mu81C6, and c) ch81C6 F(ab')(2) labeled using N-succinimidyl 3-[(131)I]iodobenzoate. Tumor retention of radioiodine activity for the F(ab')(2) fragment was comparable to that for intact ch81C6 for the first 24 h and to that for mu81C6 for the first 48 h; as expected, blood and other normal tissue levels declined faster for ch81C6 F(ab')(2.) Radiation dosimetry calculations suggest that (131)I-labeled ch81C6 F(ab')(2) may warrant further evaluation as a targeted radiotherapeutic for the treatment of brain tumors.
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PMID:Human/murine chimeric 81C6 F(ab')(2) fragment: preclinical evaluation of a potential construct for the targeted radiotherapy of malignant glioma. 1502 47

Improving drug and macromolecular delivery of anti-cancer agents to tumours results in greater efficacy without increased toxicity. The current study was undertaken to assess the effects of the timing of injection of tumour specific and non-specific monoclonal antibodies (mAbs) relative to a hyperthermia treatment on tumour and normal tissue uptake. Using a local hyperthermia protocol of 45 min at 43 degrees C, uptake in tumour and normal tissues was measured at 1, 4, 12, 24, 48 and 72 h after injection. An anti-tenascin chimeric mAb, ch81C6, served as the specific mAb in a D-54 MG glioma xenograft mouse model. The chimeric mAb chTPS3.2 served as the control. A five-to-eight-fold increase in uptake of the tumour-targeted mAb was achieved in the heated tumours when compared with the non-heated tumours at 1 h. Differences in absolute tumour uptake of the specific mAb between the mice injected prior to hyperthermia and mice injected post-hyperthermia were seen only at 1 and 12 h. The median uptakes in the tumours of mice injected pre-heat were 25%ID/g at 1 h and 43.5%ID/g at 12 h, while in the animals injected post-hyperthermia the median uptakes were 45.5%ID/g and 80.2%ID/g, respectively. Blood levels of both the specific and non-specific mAbs were consistently higher over the initial 12 h period in the mice injected post-hyperthermia. Normal tissue uptake was also increased at most time points in the mice injected post-hyperthermia. The clinical importance of the differences in specific mAb uptake in tumour detected statistically at 1 and 12 h is questionable, given the highly variable nature of mAb uptake in vivo. Tumour targeting mAbs administered in combination with heat may be injected either prior to or immediately following hyperthermia treatment, with the expectation that levels of uptake in tumour will be relatively equivalent. Absolute normal tissue levels will be higher in patients receiving the mAb post-hyperthermia.
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PMID:Enhanced tumour uptake of radiolabelled antibodies by hyperthermia: Part I: Timing of injection relative to hyperthermia. 1576 47

Clinical application of local hyperthermia as a means for modulating drug and macro-molecular tumour uptake have been slow to develop, due in part to the difficulty in designing and comparing heating protocols. The thermal isodose formula developed by Sapareto and Dewey is used in cytotoxicity and radiosensitization hyperthermia protocols to compare different time/temperature combinations; however, its relevance to other end-points has not been evaluated. The current study was undertaken to determine whether heating protocols of different time and temperature, but predicted to be thermally equivalent by this formula, had similar effects on the tumour and normal tissue distribution of radiolabelled tumour-specific (anti-tenascin 81C6) and non-specific (anti-dansyl TPS3.2) monoclonal antibodies (mAbs). Two thermally equivalent heating protocols, 4 h at 41.8 degrees C and 45 min at 43 degrees C, were compared in mice with subcutaneous D54 MG human glioma xenografts. A 4-fold increase in xenograft localization of 81C6 mAb was achieved relative to that in non-heated control groups with both heating protocols. Both hyperthermia protocols also resulted in improved tumour:normal tissue ratios. However, differences in absolute tumour and normal tissue uptake were seen, suggesting that the thermal isodose formula has limited usefulness in the design and comparison of hyperthermia protocols for enhancing the tumour uptake of radiolabelled mAbs.
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PMID:Enhanced tumour uptake of radiolabelled antibodies by hyperthermia. Part II: Application of the thermal equivalency equation. 1576 48

Malignant astrocytoma is the most common primary brain tumor in adults. The median survival time of patients with high-grade malignant astrocytoma is about 1 year, despite aggressive treatment with surgical resection, radiotherapy, and cytotoxic chemotherapy. Novel therapeutic approaches are therefore needed to prolong survival. Immunotherapy is one such novel approach that has been investigated for application with different types of tumors, including brain tumors. The author reviews immunotherapeutic approaches for malignant gliomas and the relevance of recent clinical trials and their outcomes. A number of potentially targetable antigens have been identified in gliomas. Both tenascin and epidermal growth factor receptor (EGFR) have been studied extensively as targets for direct immune attack via specific antibodies. As a novel target, interleukin 13 receptor alpha 2-chain (IL-13 R alpha 2) has been identified. IL-13 R alpha 2 is abundantly and specifically overexpressed in glioblastoma multiforme, and recently a MHC class I-restricted CTL epitope has been identified. Dendritic cells (DCs) are professional antigen presenting cells (APCs) that have a unique potency for activating T cells. DCs have been investigated in several clinical trials in patients with malignant tumors including malignant gliomas. So far, seven papers concerning immunotherapy with DCs against malignant gliomas have been published. These reports demonstrate that immunotherapy with DCs induces immune responses and clinically antitumor effects in some patients with malignant glioma. In addition, none of these studies reported evidence of autoimmune neurotoxicity.
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PMID:[Novel immunotherapeutic approach]. 1585 9

Targeting with radionuclide labelled substances that bind specifically to the epidermal growth factor receptor, EGFR, is considered for intracavitary therapy of EGFR-positive glioblastoma multiforme, GBM. Relevant literature is reviewed and examples of EGFR expression in GBM are given. The therapeutical efforts made so far using intracavitary anti-tenascin radionuclide therapy of GBM have given limited effects, probably due to low radiation doses to the migrating glioma cells in the brain. Low radiation doses might be due to limited penetration of the targeting agents or heterogeneity in the expression of the target structure. In this article we focus on the possibilities to target EGFR on the tumour cells instead of an extracellular matrix component. There seems to be a lack of knowledge on the degree of intratumoral variation of EGFR expression in GBM, although the expression seemed rather homogeneous over large areas in most of the examples (n=16) presented from our laboratory. The observed homogeneity was surprising considering the genomic instability and heterogeneity that generally characterises highly malignant tumours. However, overexpression of EGFR is, at least in primary GBMs, one of the steps in the development of malignancy, and tumour cells that lose or downregulate EGFR will probably be outgrown in an expanding tumour cell population. Thus, loss of EGFR expression might not be the critical factor for successful intracavitary radionuclide therapy. Instead, it is likely that the penetration properties of the targeting agents are critical, and detailed studies on this are urgent.
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PMID:Planning for intracavitary anti-EGFR radionuclide therapy of gliomas. Literature review and data on EGFR expression. 1620 Mar 42

Medulloblastoma spreads by leptomeningeal dissemination rather than by infiltration that characterizes other CNS tumors, eg, gliomas. This study represents an initial attempt to identify both the molecules that mediate medulloblastoma adhesion to leptomeninges and the pathways that are key to survival and proliferation of tumor following adhesion. As a first step in molecule identification, we produced adhesion of D283 medulloblastoma cells to the extracellular matrix (ECM) of H4 glioma cells in vitro. Within this context, D283 cells preferentially expressed the alpha9 and beta1 integrin subunits; antibody and disintegrin blockade of alpha9 and beta1 binding eliminated the adhesion. The H4 ECM was enriched in tenascin, a binding partner for the alpha9beta1 integrin heterodimer. Purified tenascin-C supported D283 cell adhesion. The adhesion was blocked by antibodies to alpha9 and beta1 integrin. In vivo data were similar; immunohistochemistry of primary human medulloblastomas with leptomeningeal extension demonstrated increased expression of alpha9 and beta1 integrins as well as tenascin at the interface of brain and leptomeningeal tumor. These data suggest that tumor-cell expressions of alpha9 and beta1 integrins in combination with extracellular tenascin are necessary for medulloblastoma adhesion to the leptomeninges. As a first step in the identification of pathways that mediate survival and proliferation of tumor following adhesion, we demonstrated that adhesion to H4 ECM was associated with survival and proliferation of D283 cells as well as activation of the MAPK pathway in a growth factor deficient environment. Antibody blockade of alpha9 and beta1 integrin binding that eliminated adhesion also eliminated the in vitro survival benefit. These data suggest that adhesion of medulloblastoma to the meninges is necessary for the survival and proliferation of these tumor cells at the secondary site.
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PMID:Integrins mediate adhesion of medulloblastoma cells to tenascin and activate pathways associated with survival and proliferation. 1879 52


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