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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroblastoma cell lines and tumors are characterized by low HLA class I expression. The majority of neuroblastoma cell lines and a high percentage of disseminated tumors display amplification of the nuclear protooncogene N-myc. An inverse correlation between HLA class I expression and N-myc amplification and overexpression has been recently described in neuroblastomas (NBs). In this study we have shown that cytokines (recombinant gamma-interferon, recombinant alpha-tumor necrosis factor), differentiation agents (dibutyryl cyclic AMP, phorbol myristate acetate) and growth factors (nerve growth factor, epithelial growth factor) were able to influence the growth rate and surface expression of HLA class I molecules as well as of a tumor-associated antigen on 2 representative NB cell lines. Induced decreased growth rate in NB cells was not always related to decreased N-myc expression. Analysis at the mRNA level revealed that both N-myc and HLA class I RNA steady-state levels could be modulated by several substances, including recombinant gamma-interferon, phorbol myristate acetate, dibutyryl cyclic AMP, and epithelial growth factor and were not necessarily linked. An inverse correlation between N-myc and HLA mRNA levels was observed only after exposure of NB cells to recombinant alpha-tumor necrosis factor. We conclude that N-myc and HLA class I RNA steady-state levels can be modulated independently and suggest that they are not necessarily inversely regulated.
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PMID:In vitro modulation and relationship between N-myc and HLA class I RNA steady-state levels in human neuroblastoma cells. 170 47

In vitro culture of metastatic melanoma fragments with 150 units of recombinant interleukin 2 resulted in the successive expansion of CD4+ and then CD8+ tumor-infiltrating lymphocytes (TIL) throughout a 2-month period. TIL cultured for 43 days and consisting of 95% CD8+ and 10% CD4+ T lymphocytes were cloned by limiting dilution (LD). Thirteen CD8+ and thirty-one CD4+ clones were obtained, indicating that the frequency of clonogenic CD8+ proliferative T lymphocytes was much lower than that of their CD4+ homologues. When LD was performed in the presence of autologous melanoma cells the frequency of CD8+ clones was increased by factor 4. The DNA from TIL of day 43 bulk culture and of six CD8+ clones was hybridized with T cell receptor (TcR) beta and gamma probes. Identical configuration of the nonfunctional gamma and functional beta TcR genes was found in "bulk culture" and cloned TIL. The CD8+ clones therefore derived from a clonal population of CD8+ cells which had expanded in vitro before the LD. All the CD8+ clones tested were strongly cytotoxic for autologous melanoma cells but did not kill autologous fibroblasts or concanavalin A blasts, or any of the 10 allogeneic tumor targets tested, including 5 melanomas, 2 breast cell lines, 1 neuroblastoma, K-562 and the Epstein-Barr virus-transformed cell line used as a feeder. Furthermore, specific killing was inhibited by monoclonal antibodies against CD3, CD8, TcR alpha/beta and against class I major histocompatibility complex antigens indicating that these cytotoxic T lymphocyte clones recognized autologous tumor cells through the TcR, in an HLA class I-restricted manner. These data show that it is feasible to obtain tumor-specific cytotoxic T lymphocytes from melanoma TIL with a simple culture technique and that a single clone could be expanded to more than 10(10) cells which should allow testing of immunotherapeutic potential of these cells by adoptive transfer into melanoma patients.
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PMID:Selective expansion of a specific anti-tumor CD8+ cytotoxic T lymphocyte clone in the bulk culture of tumor-infiltrating lymphocytes from a melanoma patient: cytotoxic activity and T cell receptor gene rearrangements. 197 94

In normal development the neural crest gives rise to sympathetic neuroblasts, sensory and autonomic ganglia, as well as Schwann cells. One tumor arising from this tissue is the neuroblastoma (NB), a malignancy of the adrenergic component of the sympathetic nervous system. Recent histological studies have shown that neuroblastomas can present with a schwannian cell component, rich in S100 protein. We have investigated the differentiation of NB cell lines, GOTO and RT-LN-1, into a schwannian cell phenotype using bromodeoxyuridine (BrdU). This agent induced morphological changes in these cell lines. Flat-epithelial cells were identified in the GOTO cell line and both flat-epithelial and neuronal phenotypes were found in the RT-LN-1 cell line. S100 protein (beta-Subunit) was induced in both cell lines after 18-25 days of BrdU treatment as determined by enzyme-linked immunoassay. In addition increase in the beta-subunit of S100 protein was identified in BrdU-treated flat-epithelial cells by indirect immunofluorescence using a monoclonal antibody specific for the beta-subunit of the protein. Cyclic nucleotide phosphodiesterase activity significantly increased in both BrdU-treated NB cell lines, as compared with nontreated cells. However no significant increase of glial fibrillary acidic protein in BrdU-treated cells was found either by enzyme-linked immunoassay or indirect immunofluorescence using a monoclonal antibody to glial fibrillary acidic protein. Thus, cells with Schwann cell characteristics can clearly be identified in the neuroblastoma cell lines after BrdU treatment. Fluorescence-activated cell sorting analysis revealed no quantitative changes in cell membrane antigens recognized by monoclonal antibodies UJ-13A (neuroectodermal associated antigen) and anti-Thy-1 (Thy-1) on BrdU treatment. In contrast, UJ-127-11 (neuroectodermal associated) decreased, and W6/32 and BB7.7 (HLA-ABC) and BBM.1 (beta 2-microglobulin) markedly increased in both BrdU-treated cell lines. No induction of L243 (HLA-DR), B7/21 (HLA-DP), and Genox 3.55 (HLA-DQ) was noted. The increased HLA-ABC (HLA class I) antigen may enable BrdU-treated NB cells to be recognized by cytotoxic T-cells. This may be related to the pathological evidence that NB patients whose tumors are rich in S100 protein have a better prognosis. Further studies on the potential of differentiation agents to induce a phenotypic change, that is associated with an improved prognosis for NB patients, are required.
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PMID:Schwannian cell differentiation of human neuroblastoma cell lines in vitro induced by bromodeoxyuridine. 283 49

Tissue samples and cell cultures from Wilms' tumour matched histologically normal kidney samples and EBV transformed B cells from the same patients, were analysed to detect changes in the structure and expression of the N-myc oncogene. The levels of expression of HLA class I and hypoxanthine guanine phosphoribosyl transferase were also measured in the various RNA preparations. Related tissue samples, from sources including congenital mesoblastic nephroma, paediatric neuroblastoma and a number of foetal tissues were also tested. Northern blot analysis indicated that the levels of N-myc were higher in Wilms' tumour tissues (with no parallel increase in gene copy number) compared to all other sources of material including foetal kidney. Particularly high levels of expression were observed in a number of the Wilms' tumours, several of which produced metastases. In situ hybridization, using [35S]-labelled RNA probes, confirmed that the high levels of N-myc RNA were present in the blastemal elements in the Wilms' tumour. All the tissue cultures, and tissue samples from other sources, except foetal brain and neuroblastoma, contained uniformly low levels of N-myc RNA.
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PMID:Expression of the N-myc oncogene in Wilms' tumour and related tissues. 284 12

Complementary DNAs corresponding to the interferon (IFN)-induced messenger RNAs for histocompatibility locus antigens (HLA), metallothionein-II (MT2), 2',5'-oligoadenylate synthetase and about eight other proteins of unknown sequence have been isolated recently, and by interferon regulation of transcription has been demonstrated for several of the eight mRNAs, with a significant increase apparent in as little as 5 min. We now show that IFN-alpha treatment results in a three- to fivefold increase in the transcription of MT2 and HLA class I genes in human T98G neuroblastoma cells. Furthermore, comparison of regions upstream of the MT2A gene, two HLA genes and one HLA class II gene reveals a homologous sequence of approximately 30 base pairs (bp) which may be involved in regulating transcription of interferon-induced genes. Transcription of the mRNA for human MT2A is induced by glucocorticoids or metal ions and the regulatory elements have been mapped by promoter-fusion experiments. We now show that the rate of transcription of MT2A is the same on treatment with interferon or dexamethasone, but that the mRNA accumulates much faster with dexamethasone, indicating that post-transcriptional events are important in the latter case.
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PMID:alpha-Interferon-induced transcription of HLA and metallothionein genes containing homologous upstream sequences. 399 Jul 97

Human T-lymphotropic virus type I (HTLV-I) is associated with a neurologic disease, HTLV-I-associated myelopathy-tropical spastic paraparesis, in which both pathological and immunological changes are observed within the central nervous system. The pathogenesis of infection in HTLV-I-associated myopathy-tropical spastic paraparesis is not well understood with respect to the cell tropism of HTLV-I and its relationship to the destruction of neural elements. In this study, neuroblastoma cells were infected with HTLV-I by coculturing with HUT-102 cells to demonstrate that cells of neuronal origin are susceptible to this retroviral infection. HTLV-I infection of the neuroblastoma cells was confirmed by verifying the presence of HTLV-I gp46 surface antigens by flow cytometry and by verifying the presence of HTLV-I pX RNA by Northern (RNA) blotting and in situ hybridization techniques. To determine whether HTLV-I infection could potentially lead to changes in cell surface recognition by the immune system, the infected neuroblastoma cells were analyzed for altered HLA expression. The HTLV-I-infected, cocultured neuroblastoma cells were shown, through cell surface antigen expression and RNA transcripts, to express HLA classes I and II. In contrast, cocultured neuroblastoma cells that did not become infected with HTLV-I expressed only HLA class I. HLA class I expression was enhanced by the cytokines tumor necrosis factor alpha and gamma interferon and in the presence of HUT-102 supernatant. In this system, expression of HLA class I and II molecules appeared to be regulated by different mechanisms. HLA class I expression was probably induced by cytokines present in the HUT-102 supernatant and was not dependent on HTLV-I infection. HLA class II expression required HTLV-I infection of the cells. The observation of HTLV-I infection leading to HLA induction in these neuroblastoma cells provides a possible mechanism for immunologic recognition of infected neuronal cells.
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PMID:Induction of HLA class I and class II expression in human T-lymphotropic virus type I-infected neuroblastoma cells. 790 13

Flow cytometry with the specific monoclonal antibody (MoAb) L31 was used to analyse the expression of HLA class I heavy chains not bound with beta 2-microglobulin (beta 2m) by neuroblastoma (NB) cell lines IMR-32 and LA-N-1. The cells, which express barely detectable amounts of beta 2m-free (L31-positive molecules) and beta 2m-complexed HLA class I antigens (W6.32- and BBM.1-reactive molecules), expressed MHC class I molecules not bound to light chains upon differentiation with either retinoic acid or serum starvation. The expression was not accompanied by an increase of surface heterodimers. Conversely, recombinant interferon-gamma (rIFN-gamma) treatment led IMR-32 and LA-N-1 cells to almost exclusively express beta 2m-complexes HLA class I heavy chains. Surface beta 2m-free MHC class I molecules displayed a molecular mass of approximately 45 kDa and did not bind exogenously added beta 2m. No changes in the synthesis of either HLA class I and beta 2m mRNAs or of L31 proteins were observed in differentiated NB cells, thus suggesting that the surface exposure of unusual HLA class I antigens is regulated post-translationally. These findings indicate that, in addition to activated lymphocytes, the surface expression of beta 2m-free class I heavy chains is a feature of other cell types, such as NB cells.
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PMID:Expression of beta 2m-free HLA class I heavy chains in neuroblastoma cell lines. 831 64

Epitope mapping of HLA-Cw4 indicates that the two monoclonal antibodies (mAbs) L31 and M38, specific for beta 2-microglobulin (beta2m)-free HLA-C heavy chains, react preferentially with the KYK motif, located in the binding groove (alpha1 domain). Transfection of HLA-Cw4 cDNA into a neuroblastoma cell line, which normally expresses negligible HLA class I, resulted in the constitutive surface expression of molecules displaying different reactivities with the two mAbs. This cellular system was used to determine whether L31 and M38 recognize distinct conformations of beta2m-free HLA-C proteins, and to investigate their mechanism of expression. Interferon-gamma greatly enhanced the expression of L31-reactive free chains, while abolishing that of M38-reactive molecules. The cytokine-induced expression of L31-reactive molecules was inhibited by anti-sense oligonucleotides specific for beta2m mRNA, while constitutive expression of L31-reactive molecules was only partially affected. Exogenous beta2m resulted in a reduction of constitutive L31 reactivity, and in a concomitant increase of M38 reactivity. These results indicate that: 1) at the cell surface, L31 and M38 react with two distinct conformations of HLA-Cw4 beta2m-free heavy chains, of which the L31-reactive conformation is the least folded; 2) the expression of both conformers can be modulated by endogenous or exogenous beta2m; and (3) L31-reactive molecules exposed at the cell surface are likely to derive from the dissociation of empty HLA-Cw4/beta2m complexes.
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PMID:Expression of distinct conformations of free HLA-Cw4 heavy chains in transfected neuroblastoma cells. 911 Sep 32

The surface receptors involved in natural killer (NK) cell triggering during the process of target cell lysis have been at least in part identified. These are members of a novel family of receptors that has been termed natural cytotoxicity receptors (NCR). The first three members of this emerging group of receptors are the NKp46, NKp44 and NKp30 molecules that all belong to the immunoglobulin superfamily. Blocking of these receptors inhibits NK-mediated cytotoxicity against a wide variety of tumor target cells. In the present study, we show that these NCR are also involved in NK-mediated killing of tumor cells of neural origin. Glioblastoma and neuroblastoma target cells were efficiently killed by all NK clones analyzed since little protection from NK lysis was mediated by HLA class I molecules. Blocking of one or another NCR inhibited cytotoxicity; however, optimal inhibition was only observed when the three receptors were blocked simultaneously. A sharp difference in cytotoxicity against neural tumors was demonstrated between NCR(bright) and NCR(dull) NK clones, further supporting the notion that NCR play a critical role in the induction of cytotoxicity against tumor target cells of different histotype. Finally, our data also indicate that CD16 does not function as a triggering receptor involved in lysis of neural tumors since no difference in cytotoxicity could be substantiated between CD16(+) and CD16(-) NK clones and no correlation could be detected between the NCR(bright)/NCR(dull) phenotype and CD16 expression.
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PMID:Involvement of natural cytotoxicity receptors in human natural killer cell-mediated lysis of neuroblastoma and glioblastoma cell lines. 1085 60

We studied the constitutive and the interferon (IFN)-gamma-induced expression of HLA class I antigen heavy chain, beta2-microglobulin (beta2m), TAP-1, TAP-2 and tapasin in a panel of eleven neuroblastoma cell lines. Surface expression of HLA class I antigens was low in eight out of eight neuroblastoma cell lines bearing MYC-N amplification and/or 1p deletion, while two out of three neuroblastoma cell lines lacking these genetic alterations showed normal expression. IFN-gamma treatment restored HLA class I antigen surface expression in all neuroblastoma cell lines. Eight out of 11 neuroblastoma cell lines did not express TAP-1 mRNA and three of them also lacked TAP-2 mRNA. beta2 m mRNA was barely detectable or absent in five neuroblastoma cell lines, while tapasin mRNA was always expressed. IFN-gamma upregulated the expression of HLA class I heavy chain, beta2 m, TAP-1, TAP-2 and tapasin, as detected at mRNA or protein level. Post-transcriptional events were involved in altered TAP-1 and beta2 m expression in one peculiar neuroblastoma cell line. These data indicate that multiple mechanisms play a role in the HLA class I antigen-deficient phenotype of human neuroblastoma.
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PMID:Lack of HLA-class I antigens in human neuroblastoma cells: analysis of its relationship to TAP and tapasin expression. 1126 May 5


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