UMLS:C0017638 - FACTA Search

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

The discovery of a novel cytosine nucleoside, beta-D-2', 3'-didehydro-2',3'-dideoxy-5-fluorocytidine (D-D4FC), as a potent antihuman immunodeficiency virus (HIV) agent led us to synthesize a series of analogues and derivatives of beta-D-D4FC that could be more selective and also possess increased glycosidic bond stability. The synthesized D-D4FC analogues were evaluated for anti-HIV-1 activity, anticancer activity, and cytotoxicity in various cells. The biological data demonstrated that the 5-substitution of beta-D-D4FC with bromine (6c) and iodine (6d) resulted in the loss of antiviral activity, and the alpha-D anomer (7a) of D-D4FC was also devoid of activity. The 5-fluorouracil analogues (6b and 7b) of D-D4FC were less potent and more cytotoxic than the parent compound, whereas the beta-L-D4FU (11) showed both potent anti-HIV-1 activity and cytotoxicity. N4- and 5'-O-acyl derivatives (17, 15a-c) of beta-D-D4FC exhibited comparable antiviral activity to beta-D-D4FC. In contrast, the N4-isopropyl derivative (20) of beta-D-D4FC was not active against HIV-1, even at 100 microM. The carbocyclic analogues (26a,b) of D4FC demonstrated weak activity against HIV-1 and no toxicity in various cells. The triphosphates (27a,b) of the carbocyclic nucleosides demonstrated potent inhibitory activity against recombinant HIV-1 reverse transcriptase at submicromolar concentrations. Of the compounds tested as potential anticancer agents, beta-D-, alpha-D-, and beta-L-D4FU (6b, 7b, 11) showed inhibitory activity against rat glioma and modest activity against human lung carcinoma, lymphoblastoid, and skin melanoma cells.
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PMID:Synthesis and biological evaluation of 2',3'-didehydro-2',3'- dideoxy-5-fluorocytidine (D4FC) analogues: discovery of carbocyclic nucleoside triphosphates with potent inhibitory activity against HIV-1 reverse transcriptase. 1007 83

Twelve G protein-coupled receptors, including chemokine receptors, act as coreceptors and determinants for the cell tropisms of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We isolated HIV-1 variants from T-cell-line (T)- and macrophage (M)-tropic (i.e., dualtropic) (R5-R3-X4) HIV-1 strains and also produced six HIV-1 mutants carrying single-point amino acid substitutions at the tip of the V3 region of the Env protein of HIV-1. These variants and three mutants infected brain-derived CD4-positive cells that are resistant to M-, T-, or dualtropic (R5, X4, or R5-X4) HIV-1 strains. However, a factor that determines this cell tropism has not been identified. This study shows that primary brain-derived fibroblast-like cell strains, BT-3 and BT-20/N, as well as a CD4-transduced glioma cell line, U87/CD4, which were susceptible to these HIV-1 variants and mutants and the HIV-2ROD strain, expressed mRNA of an orphan G protein-coupled receptor (GPCR), GPR1. When a CD4-positive cell line which was strictly resistant to infection with diverse HIV-1 and HIV-2 strains was transduced with GPR1, the cell line became susceptible to these HIV-1 variants and mutants and to an HIV-2 strain but not to T- or dualtropic HIV-1 strains, and numerous syncytia formed after infection. These results indicate that GPR1 functions as a coreceptor for the HIV-1 variants and mutants and for the HIV-2ROD strain in vitro.
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PMID:An orphan G protein-coupled receptor, GPR1, acts as a coreceptor to allow replication of human immunodeficiency virus types 1 and 2 in brain-derived cells. 1023 94

CD4 and one of the G-protein-coupled receptors (GPCRs) on the cell surface function as a receptor and a coreceptor, respectively, in infection of cells with human and simian immunodeficiency viruses (HIV/SIV). To determine which GPCRs can be coreceptors for HIV (HIV-1 and HIV-2) or SIV infection, several cell lines, including human osteosarcoma HOS-T4 cells and human glioma U87/CD4 cells, have been used. However, these cells often show susceptibilities to some HIV or SIV strains before transduction of GPCRs. The results of this study showed that a CD4-transduced human glioma cell line, NP-2/CD4, a human erythroleukemia cell line, K562/CD4, and a human ovarian cancer cell line, TYK/CD4, were completely resistant to the HIV-1 and HIV-2 strains tested. After transduction of several GPCRs into NP-2/CD4, K562/CD4, or TYK/CD4 cells, NP-2/CD4 cells but not K562/CD4 or TYK/CD4 cells mostly showed expected susceptibilities to several HIV strains. Therefore, an NP-2 cell system would be useful to determine the coreceptor usage of HIV isolates, to find a new coreceptor for HIV/SIV, and to analyze the early stages of HIV/SIV infection.
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PMID:Establishment of a new system for determination of coreceptor usages of HIV based on the human glioma NP-2 cell line. 1032 84

We examined the effect of amino acid substitutions of the GPGR (glycine-proline-glycine-arginine) tip sequence at the V3 domain of the Env protein of human immunodeficiency virus type 1 (HIV-1) on its cell tropism and coreceptor use. We changed the GPGR sequence of a T-cell line (T)- and macrophage (M)-tropic (R5-R3-X4) HIV-1 strain, GUN-1wt, to GA(alanine)GR (the resulting mutant was designated GUN-1/A), GL(leucine)GR (GUN-1/L), GP(proline)GR (GUN-1/P), GR(arginine)GR (GUN-1/R), GS(serine)GR (GUN-1/S), or GT(threonine)GR (GUN-1/T). GUN-1/A, GUN-1/S, and GUN-1/T mutants infected brain-derived cells such as a CD4-transduced glioma cell line, U87/CD4, and a brain-derived primary cell strain, BT-20/N, as well as T-cell lines in a CD4-dependent manner, although the plating of these mutants onto macrophages was inhibited. GUN-1/L, GUN-1/P, and GUN-1/R mutants showed both T- and M-tropism, but did not plate onto the brain-derived cells. A CCR3, CCR5, CCR8, or CXCR4 gene was introduced into a CD4-positive glioma cell line, NP-2/CD4, which demonstrated complete resistance to various HIV-1 strains. Not only HIV-1 strains, which were infectious to macrophages, such as GUN-1wt, GUN-1v, GUN-1/L, and GUN-1/P, but also an HIV-1 strain, GUN-1v, which was hardly infectious to macrophages, grew well in NP-2/CD4 cells expressing CCR3 or CCR5. However, the M-tropic GUN-1/R mutant could not efficiently use CCR5 nor CCR3. No point mutants, except GUN-1/L, grew well in NP-2/CD4 cells expressing CCR8. These findings indicate that the cell tropism of HIV-1 to macrophages and brain-derived cells and their use of the coreceptors were markedly, though not always concomitantly, affected by the tip sequence of the V3 domain.
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PMID:Changes in and discrepancies between cell tropisms and coreceptor uses of human immunodeficiency virus type 1 induced by single point mutations at the V3 tip of the env protein. 1038 57

The paper describes the most infrequent case of cryptococcal granuloma of the midbrain in a HIV-negative female patient aged 41 years. The patient with midbrain lesion without signs of meningitis was found to have a bulky midbrain opercular formation that was regarded as a nodal glioma. The diagnosis of cryptococcal granuloma was established after removal of the formation (via occipito-transtentorial access with dissection of the lamina tecti) and pathomorphological examination. Microbiological studies verified the diagnosis. Despite the initiation of specific treatment with amphotericin B, the patient died on day 12 following surgery for cryptococcal meningoencephalitis.
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PMID:[A cryptococcal granuloma of the midbrain]. 1042 May 45

G protein-coupled receptors serve as coreceptors in the infection process of human immunodeficiency virus type-1 (HIV-1), type-2 (HIV-2), and simian immunodeficiency virus (SIV). In this study, we showed that a CXC-CKR, CXCR5/BLR1, is a novel coreceptor for HIV-2, but for neither HIV-1 nor SIV. The expression of CXCR5 was detected by polymerase chain reaction after reverse transcription of cellular mRNA from S+L-HOS/CD4 cells and MT-2 human T cells, and the CXCR5 gene was cloned into an expression vector. S+L-HOS/CD4 cells were susceptible to several HIV-2 strains but not most HIV-1 strains. To examine a coreceptor activity of CXCR5, we used NP-2/CD4, which is a human glioma cell line, NP-2, transduced with the CD4 gene that shows strict resistance to infection with HIV-1, HIV-2, SIVmac, SIVagm, or SIVmnd strain. When CXCR5 was transduced into NP-2/CD4 cells, they became highly susceptible to HIV-2ROD and HIV-2CBL23 strains in a CD4-dependent manner but to not to HIV-1 or SIV strains. Anti-CXCR5 monoclonal antibody and a ligand for CXCR5, BCA-1, inhibited HIV-2 infection to NP-2/CD4/CXCR5 cells. Our findings suggest a possibility that CXCR5/BLR1 serves as a coreceptor for HIV-2 strains in vivo.
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PMID:A CXC chemokine receptor, CXCR5/BLR1, is a novel and specific coreceptor for human immunodeficiency virus type 2. 1060 May 98

More than 10 G protein-coupled receptors (GPCRs) have been shown to act as coreceptors for infection of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We have isolated HIV-1 variants infectious to primary brain-derived CD4-positive cells (BT-3 and BT-20/N) and U87/CD4 glioma cells that are resistant to T-cell line-tropic (T-tropic), macrophage-tropic (M-tropic), and T- and M-tropic (dualtropic) (X4, R5, and R5X4) HIV-1 strains. These primary brain-derived cells were also highly susceptible to HIV-2(ROD), HIV-2(SBL6669), and SIV(mndGB-1). A factor or coreceptor that determines the susceptibility of these brain-derived cells to these HIV and SIV strains has not been fully identified. To identify this coreceptor, we examined amino acid sequences of all known HIV and SIV coreceptors and noticed that tyrosine residues are well conserved in their extracellular amino-terminal domains. By this criterion, we selected 18 GPCRs as candidates of coreceptors for HIV and SIV strains infectious to these brain-derived cells. mRNA expression of an orphan GPCR, RDC1, was detected in the brain-derived cells, the C8166 T-cell line, and peripheral blood lymphocytes, all of which are susceptible to HIV-1 variants, but not in macrophages, which are resistant to them. When a CD4-expressing cell line, NP-2/CD4, which shows strict resistance to infection not only with HIV-1 but also with HIV-2 or SIV, was transduced with the RDC1 gene, the cells became highly susceptible to HIV-2 and SIV(mnd) strains but to neither M- nor T-tropic HIV-1 strains. The cells also acquired a low susceptibility to the HIV-1 variants. These findings indicate that RDC1 is a novel coreceptor for several HIV-1, HIV-2, and SIV strains which infect brain-derived cells.
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PMID:A putative G protein-coupled receptor, RDC1, is a novel coreceptor for human and simian immunodeficiency viruses. 1062 23

RGS proteins comprise a family of proteins named for their ability to negatively regulate heterotrimeric G protein signaling. Biochemical studies suggest that members of this protein family act as GTPase-activating proteins for certain Galpha subunits, thereby accelerating the turn-off mechanism of Galpha and terminating signaling by both Galpha and Gbetagamma subunits. In the present study, we used confocal microscopy to examine the intracellular distribution of several RGS proteins in COS-7 cells expressing RGS-green fluorescent protein (GFP) fusion proteins and in cells expressing RGS proteins endogenously. RGS2 and RGS10 accumulated in the nucleus of COS-7 cells transfected with GFP constructs of these proteins. In contrast, RGS4 and RGS16 accumulated in the cytoplasm of COS-7 transfectants. As observed in COS-7 cells, RGS4 exhibited cytoplasmic localization in mouse neuroblastoma cells, and RGS10 exhibited nuclear localization in human glioma cells. Deletion or alanine substitution of an N-terminal leucine repeat motif present in both RGS4 and RGS16, a domain identified as a nuclear export sequence in HIV Rev and other proteins, promoted nuclear localization of these proteins in COS-7 cells. In agreement with this observation, treatment of mouse neuroblastoma cells with leptomycin B to inhibit nuclear protein export by exportin1 resulted in accumulation of RGS4 in the nucleus of these cells. GFP fusions of RGS domains of RGS proteins localized in the nucleus, suggesting that nuclear localization of RGS proteins results from nuclear targeting via RGS domain sequences. RGSZ, which shares with RGS-GAIP a cysteine-rich string in its N-terminal region, localized to the Golgi complex in COS-7 cells. Deletion of the N-terminal domain of RGSZ that includes the cysteine motif promoted nuclear localization of RGSZ. None of the RGS proteins examined were localized at the plasma membrane. These results demonstrate that RGS proteins localize in the nucleus, the cytoplasm, or shuttle between the nucleus and cytoplasm as nucleo-cytoplasmic shuttle proteins. RGS proteins localize differentially within cells as a result of structural differences among these proteins that do not appear to be important determinants for their G protein-regulating activities. These findings suggest involvement of RGS proteins in more complex cellular functions than currently envisioned.
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PMID:Cytoplasmic, nuclear, and golgi localization of RGS proteins. Evidence for N-terminal and RGS domain sequences as intracellular targeting motifs. 1079 63

Recent evidence suggests that HIV-1 Vpr exists in soluble form in the serum and cerebrospinal fluid (CSF). Further, its abundance in the bloodstream, and the CSF, and its activity on other cell types suggest that it could have an effect on brain activity. Using mixed embryonic rat brain cultures as a model to examine the effects of physiological concentrations of extracellular Vpr protein, Vpr-induced cell death was observed. We also observed similar Vpr-induced effects in enriched primary cortical rat astrocytes, as well as in the C6 glioma cell line. Vpr-induced cell death observed in the astrocytic cells appeared to be caused primarily by a necrotic mechanism, although a few apoptotic nuclei were also present. We did not observe Vpr-induced effects on any primary cortical neurons, although we did observe Vpr-induced cell death in hippocampal neurons and astrocytes. Finally, we observed no cell cycle effects due to extracellular Vpr protein. This data points out that different cell types are affected by the toxic effects of extracellular Vpr protein, and that differential toxic effects of extracellular Vpr protein are observed in similar cell types.
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PMID:Effects of extracellular human immunodeficiency virus type 1 vpr protein in primary rat cortical cell cultures. 1151 91

Brain tumor incidence has increased over the last 20 years in all age groups, both overall and for specific histologies. Reasons attributed to these increases include increase in lymphoma due to HIV/AIDS, introduction of computed tomography/magnetic resonance imaging, and changes in coding/classification. The purpose of this study was to describe overall and histologic-specific incidence trends in a population-based series of primary benign and malignant brain tumors. Data from the Central Brain Tumor Registry of the United States from 1985 through 1994 were used to determine incidence trends in the broad age groups 0-19, 20-64, and > or = 65 years, both overall and for selected histologies. Poisson regression was used to express trends as average annual percentage change. Overall, incidence increased modestly (annual percentage change 0.9%, 95% confidence interval, 0.4, 1.4). When lymphomas were excluded, this result was not statistically significant (annual percentage change 0.5%, 95% confidence interval, -0.1, 1.1). Specific histologies that were increasing were lymphomas in individuals aged 20 to 64 years and in males aged 65 years or older, ependymomas in the population aged 20 to 64 years, nerve sheath tumors in males, and pituitary tumors in females. Increases that were not specific to any population subgroup were seen for glioblastoma, oligodendrogliomas, and astrocytomas, excluding not otherwise specified (NOS) tumors. Corresponding decreases were noted for NOS, astrocytoma NOS, and glioma NOS. Increasing incidence trends for lymphomas were consistent with previous literature. Improvements in diagnostic technology in addition to changes in classification and coding were likely to be responsible for decreases seen in incidence of NOS subgroups and corresponding increases in glioma subgroups. In contrast, the increases identified for ependymomas, nerve sheath tumors, and pituitary tumors were less likely to be artifacts of improvements in diagnosis, and they warrant further study.
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PMID:Trends in incidence of primary brain tumors in the United States, 1985-1994. 1146 94

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