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)

4-1BB is an inducible receptor-like protein expressed rapidly by both CD4 and CD8 T-cells after activation. 4-1BB cross-linking, either by binding to 4-1BBL or by antibody ligation, delivers a costimulatory signal to enhance T-cell activation and proliferation. Previous studies have demonstrated that the administration of 4-1BB monoclonal antibodies (mAbs) induces antitumor immune responses. In the current study using several murine tumors, we examined the systemic effects of 4-1BB mAb on the growth of s.c., intracranial (i.c.), and pulmonary metastases. In addition, the effects of 4-1BB mAb on the generation of antitumor effector T cells were examined. Treatment of 3-day i.c. MCA 205 sarcoma and GL261 glioma with the antibody resulted in prolongation of survival and cure of disease in some mice, whereas only minimal therapeutic effects were observed in established s.c. and pulmonary tumors. No antitumor effects against the poorly immunogenic B16/D5 melanoma were observed. Interestingly, successful treatment of i.c. tumors induced concomitant regression of s.c. tumors. Experiments using severe combined immunodeficient mice and mice depleted of either CD4 or CD8 T cells demonstrated T-cell dependence of the antitumor effects. For generation of effector T cells in the tumor-draining lymph nodes (LNs), administration of 4-1BB mAb had adverse effects, despite the apparent hypertrophy of the LNs. During in vitro activation of tumor-draining LN T cells with anti-CD3 and interleukin 2, the 4-1BB mAb augmented proliferation, resulting in an increase in CD8 T cells. However, they were less therapeutic than not treated LN cells. In adoptive immunotherapy, the coadministration of 4-1BB mAb enhanced the therapeutic efficacy. These results thus demonstrate the limits and potential advantages of 4-1BB antibody interactions with antitumor T cells in vivo and in vitro and suggest that therapeutic interactions of the antibody may be used in a variety of immunotherapeutic approaches.
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PMID:Divergent effects of 4-1BB antibodies on antitumor immunity and on tumor-reactive T-cell generation. 1128 Jul 63

Halofuginone, a widely used alkaloid coccidiostat, is a potent inhibitor of collagen alpha 1 (I) and matrix metalloproteinase 2 gene expression. Halofuginone also suppresses extracellular matrix deposition and fibroblast proliferation. It was recently shown to be effective in suppression of bladder carcinoma and glioma. This study sought to evaluate the effect of treatment with halofuginone on growth of hepatocellular carcinoma (HCC) in mice. Athymic Balb/c mice were injected subcutaneously with 10(7) human hepatoma cells (Hep3B), followed by treatment with halofuginone administered in the diet (750 microg/kg) starting on day 3, before tumour innoculation. The control group was received a normal diet. Mice were followed for survival, tumour volume and serum alpha-fetoprotein (alpha FP). The mechanism of the anti-tumour effect of halofuginone was determined in vitro by assessing tumour cell growth, and by measuring the serum concentrations of interferon-gamma (IFN gamma) and interleukin 2 (IL2). Halofuginone treatment induced almost complete tumour suppression in treated mice. Mortality rates were 10% and 50%, in halofuginone-treated and control mice, respectively (P<0.001). No visible tumour was observed in treated mice, as compared with a 364 mm3 tumour in control mice. Serum alpha FP were 0.1 and 212 ng/ml in treated and control mice, respectively (P<0.005). Halofuginone significantly inhibited HCC proliferation in vitro. Maximal inhibition of 64% of tumour cell growth was observed at a concentration of 10(-8) M. The anti-tumour effect was mediated via a significant increase in IFN gamma and IL2 (90 vs. 35, and 210 vs. 34 pg/ml in treated and control groups, respectively, P<0.005). Treatment with halofuginone effectively suppressed the progression of HCC in mice. This effect may be associated with a direct anti-tumour effect, and/or enhancement of a systemic immune response.
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PMID:Suppression of hepatocellular carcinoma growth in mice by the alkaloid coccidiostat halofuginone. 1517 99

Immune infiltration of advanced human gliomas has been shown, but it is doubtful whether these immune cells affect tumor progression. It could be hypothesized that this infiltrate reflects recently recruited immune cells that are immediately overwhelmed by a high tumor burden. Alternatively, if there is earlier immune detection and infiltration of the tumor, the question arises as to when antitumor competency is lost. To address these issues, we analyzed a transgenic mouse model of spontaneous astrocytoma (GFAP-V(12)HA-ras mice), which allows the study of immune interactions with developing glioma, even at early asymptomatic stages. T cells, including a significant proportion of Tregs, are already present in the brain before symptoms develop, followed later by macrophages, natural killer cells, and dendritic cells. The effector potential of CD8 T-cells is defective, with the absence of granzyme B expression and low expression of IFN-gamma, tumor necrosis factor, and interleukin 2. Overall, our results show an early defective endogenous immune response to gliomas, and local accumulation of immunosuppressive cells at the tumor site. Thus, the antiglioma response is not simply overwhelmed at advanced stages of tumor growth, but is counterbalanced by an inhibitory microenvironment from the outset. Nevertheless, we determined that effector molecule expression (granzyme B, IFN-gamma) by brain-infiltrating CD8 T-cells could be enhanced, despite this unfavorable milieu, by strong immune stimuli. This potential to modulate the strong imbalance in local antiglioma immunity is encouraging for the development and optimization of future glioma immunotherapies.
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PMID:Immune infiltration of spontaneous mouse astrocytomas is dominated by immunosuppressive cells from early stages of tumor development. 2050 37


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