Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the mechanism by which HIV-1 infects neurons we have used human neuroblastoma cell lines (NB). NB (SK-N-SH and SK-N-MC) were found to be susceptible to productive infection by X4 or R5 HIV-1, as detected by viral load and Ag-p24. To identify the putative receptor, we tested the cell surface expression of previously described receptors such as CD4, nucleolin, galactosylceramide, and CCR1, CCR5, and CXCR4 by cytometry and RT-PCR. NB express no CD4 and low levels of galactosylceramide or nucleolin. Furthermore, antibodies to any of these molecules did not affect NB infection. NB express variable levels of CCR5, CCR1, and CXCR4. Interestingly, exogenous heparan sulfate alone was able to substantially inhibit HIV-1 infection, an effect which was potentiated by RANTES or SDF-1 in the HIV-1-infection with R5 or X4 isolates. Besides, anti-CCR5 and anti-CXCR4 significantly blocked HIV-1 infection of R5 and X4 isolates. Our results suggest that HIV-1 entry involves a chemokine-receptor-dependent but CD4-independent entry in neural cells.
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PMID:A new possible mechanism of human immunodeficiency virus type 1 infection of neural cells. 1258 55

Human neuroblastoma SK-N-SH cells strongly express CXC-chemokine receptor 4 (CXCR4), the principal coreceptor for X4 HIV-1 strains, and its natural ligand stromal cell-derived factor 1 (SDF-1, recently renamed CXCL12). We investigated the impact of CXCR4 blockade by the specific CXCR4 antagonist AMD3100 or by X4 HIV-1 virus particles on the growth and survival of neuroblastoma SK-N-SH cells. SK-N-SH cell proliferation was inhibited byAMD3100 and anti-CXCL12 neutralizing antibodies, but enhanced by exogenously added CXCL12. Upon prolongedexposure to AMD3100, SK-N-SH cell death occurred throughdeficit of survival-promoting and growth-stimulatory signals generated by endogenous CXCL12. In analogy with the observations made with the CXCR4 inhibitor AMD3100, the X4 HIV-1 strains IIIB and SF-2, but not the R5 strain BaL, caused a marked cytopathic effect and strongly effected SK-N-SH cell death after at least 10 days of incubation. However, no virus production could be detected in the HIV-1-inoculated SK-N-SH cell cultures. Exogenously added CXCL12 afforded partial protection against X4 HIV-1-induced cytopathicity in SK-N-SH cells. Our data indicate that the endogenous CXCL12/CXCR4 signaling axis is critical for neuroblastoma cell survival and proliferation. Long-term blockade of CXCR4 through physical contact with the X4 HIV-1 envelope can cause neuronal cell death. This mechanism may possibly play a role in X4 HIV-associated neurodegeneration.
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PMID:X4 HIV-1 induces neuroblastoma cell death by interference with CXCL12/CXCR4 interaction. 1499 74

In previous studies, we demonstrated that human neuroblastoma cells are equipped with the machinery to direct their homing to bone marrow. These tumor cells express the CXCR4 receptor for the bone marrow stroma-derived chemokine CXCL12 (SDF-1) and secrete the CXCL12 ligand. The present study was undertaken to explore possible differences in gene-expression patterns between neuroblastoma variants that over-express CXCR4 (designated STH cells) and those which express very little of this receptor (STL cells). The results of the study clearly indicate that these variants show a differential gene-expression profile. They differ in expression of some integrins such as VLA2, VLA3 and VLA6, of neuroendocrine-markers such as CD56 and synaptophysin, in the expression of c-kit and in the secretion of certain cytokines and growth factors such as TNFalpha, SDF-1, VEGF, IL-8, GM-CSF and IP-10. We hypothesize that these differences are due to an autocrine SDF-1alpha-CXCR4 axis.
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PMID:The tumor microenvironment: CXCR4 is associated with distinct protein expression patterns in neuroblastoma cells. 1508 41

CD1d-restricted Valpha24-Jalpha18-invariant natural killer T cells (iNKTs) are potentially important in tumor immunity. However, little is known about their localization to tumors. We analyzed 98 untreated primary neuroblastomas from patients with metastatic disease (stage 4) for tumor-infiltrating iNKTs using TaqMan((R)) reverse transcription polymerase chain reaction and immunofluorescent microscopy. 52 tumors (53%) contained iNKTs, and oligonucleotide microarray analysis of the iNKT(+) and iNKT(-) tumors revealed that the former expressed higher levels of CCL2/MCP-1, CXCL12/SDF-1, CCL5/RANTES, and CCL21/SLC. Eight tested neuroblastoma cell lines secreted a range of CCL2 (0-21.6 ng/ml), little CXCL12 (</=0.1 ng/ml), and no detectable CCL5 or CCL21. CCR2, the receptor for CCL2, was more frequently expressed by iNKT compared with natural killer and T cells from blood (P < 0.001). Supernatants of neuroblastoma cell lines that produced CCL2 induced in vitro migration of iNKTs from blood of patients and normal adults; this was abrogated by an anti-CCL2 monoclonal antibody. CCL2 expression by tumors was found to inversely correlate with MYCN proto-oncogene amplification and expression (r = 0.5, P < 0.001), and MYCN-high/CCL2-low expression accurately predicted the absence of iNKTs (P < 0.001). In summary, iNKTs migrate toward neuroblastoma cells in a CCL2-dependent manner, preferentially infiltrating MYCN nonamplified tumors that express CCL2.
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PMID:Natural killer T cells infiltrate neuroblastomas expressing the chemokine CCL2. 1512 43

Bone marrow stroma cells secrete the chemokine CXCL12 that may support bone marrow metastasis formation by neuroblastoma cells. The present study demonstrates that bone marrow stroma cell lines also secrete CXCL10, a chemokine that was shown in the past to have anti-malignancy functions. A receptor recognized by antibodies against CXCR3 was shown to be expressed by six neuroblastoma cell lines. Further detailed analysis was performed on the NUB6 and SK-NMC neuroblastoma cells, showing that CXCL10 induced potent Erk phosphorylation in a G(alpha)i-dependent manner. The role of a CXCR3-like receptor in Erk phosphorylation was substantiated by the ability of CXCL11, another potent CXCR3 ligand, to induce Erk phosphorylation in the NUB6 and SK-NMC cells. Further characterization of CXCL10 activities indicated that CXCL10 partly inhibited the growth of the NUB6 and SK-NMC cells. Both NUB6 and SK-NMC cells did not migrate to CXCL10, although their migratory machinery was intact, as evidenced by their migration to bone marrow constituents. Altogether, these results suggest that CXCL10 interacts with a CXCR3-like receptor in neuroblastoma cell lines, raising the possibility that following the homing of the tumor cells to the bone marrow (through a CXCL10-independent mechanism), CXCL10 may partly inhibit neuroblastoma cell growth at this site.
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PMID:Cellular characteristics of neuroblastoma cells: regulation by the ELR--CXC chemokine CXCL10 and expression of a CXCR3-like receptor. 1561 78

The chemokine receptor CXCR4 functions as human immunodeficiency virus (HIV)-1 coreceptor and is involved in acquired immunodeficiency virus (AIDS) neuropathogenesis. CXCR4 is expressed by most cell types in the brain, including microglia, astrocytes, and neurons. Studies have shown that the HIV envelope protein gp120 binds to neuronal CXCR4 and activates signal transduction pathways leading to apoptosis. However, the natural CXCR4 ligand (CXCL12) has been referred to induce both neuronal survival and death. Here the authors used flow cytometry to determine whether gp120 and CXCL12 differ in their ability to induce CXCR4 internalization in the human neuroblastoma cells SH-SY5Y, which constitutively express CXCR4. As expected, increasing concentration of CXCL12 reduced surface expression of CXCR4 in a time-and concentration-dependent manner. Conversely, gp120IIIB (monomeric or oligomeric, in presence or absence of soluble CD4) did not change CXCR4 membrane levels. Similar results were obtained in a murine lymphocyte cell line (300-19) stably expressing human CXCR4. Nevertheless, gp120IIIB was still able to activate intracellular signaling and proapoptotic pathways, via CXCR4. These results show that gp120IIIB toxicity and signaling do not require CXCR4 internalization in SH-SY5Y cells, and suggest that the viral protein may alter normal CXCR4 trafficking thus, interfering with activation of prosurvival pathways.
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PMID:Human immunodeficiency virus gp120-induced apoptosis of human neuroblastoma cells in the absence of CXCR4 internalization. 1687 2

Neuroblastoma (NB) is a heterogeneous, and particularly malignant childhood neoplasm in its higher stages, with a propensity to form metastasis in selected organs, in particular liver and bone marrow, and for which there is still no efficient treatment available beyond surgery. Recent evidence indicates that the CXCR4/CXCL12 chemokine/receptor axis may be involved in promoting NB invasion and metastasis. In this study, we explored the potential role of CXCR4 in the malignant behaviour of NB, using a combination of in vitro functional analyses and in vivo growth and metastasis assessment in an orthotopic NB mouse model. We show here that CXCR4 overexpression in non-metastatic CXCR4-negative NB cells IGR-NB8 and in moderately metastatic, CXCR4 expressing NB cells IGR-N91, strongly increased tumour growth of primary tumours and liver metastases, without altering the frequency or the pattern of metastasis. Moreover shRNA-mediated knock-down experiments confirmed our observations by showing that silencing CXCR4 in NB cells impairs in vitro and almost abrogates in vivo growth. High levels of CXCL12 were detected in the mouse adrenal gland (the primary tumour site), and in the liver suggesting a paracrine effect of host-derived CXCL12 on NB growth. In conclusion, this study reveals a yet unreported NB-specific predominant growth and survival-promoting role of CXCR4, which warrants a critical reconsideration of the role of CXCR4 in the malignant behaviour of NB and other cancers.
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PMID:The chemokine receptor CXCR4 strongly promotes neuroblastoma primary tumour and metastatic growth, but not invasion. 1792 64

Many cancer cells display down-regulated major histocompatibility complex (MHC) class I antigen (MHC-I), which seems to enable them to evade immune surveillance, whereas the underlying mechanisms remain incompletely understood. Here, we demonstrate that ligand (CXCL12) stimulation of CXCR4, a major chemokine receptor expressed in many malignant cancer cells, induced MHC-I heavy chain down-regulation from the cell surface of the human epithelioid carcinoma HeLa cells, the human U251 and U87 glioblastoma cells, the human MDA-MD 231 breast cancer cells, and the human SK-N-BE (2) neuroblastoma cells. Activation of CXCR4 also induced MHC-I down-regulation in human peripheral blood mononuclear cells. The internalized MHC-I heavy chain molecules were partially co-localized with Rab7, a later endosomal marker. Activation of CXCR4 induced ubiquitination of MHC-I heavy chain, and mutation of the C-terminal two lysine residues (Lys-332, Lys-337) on one of the MHC-I alleles, HLA.B7, blocked CXCR4-evoked ubiquitination and down-regulation of HLA.B7. Moreover, purified GST-conjugated CXCR4 C terminus directly associated with the purified His-tagged beta2-microglobulin (beta2M), and MHC-I heavy chain was co-immunoprecipitated with CXCR4 in a beta2M-dependent manner. This interaction appears to be critical for CXCR4-evoked down-regulation of MHC-I heavy chain as evidenced by the data that MHC-I heavy chain down-regulation was inhibited by either truncation of the CXCR4 C terminus or knockdown of beta2M. All together, these findings shed new light on the role of CXCR4 in tumor evasion of immune surveillance via inducing MHC-I down-regulation from the cell surface.
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PMID:Activation of CXCR4 triggers ubiquitination and down-regulation of major histocompatibility complex class I (MHC-I) on epithelioid carcinoma HeLa cells. 1808 6

Neuroblastoma is the second most common pediatric malignancy. The clinical course of this disease ranges from spontaneous regression and good survival to highly malignant therapy-resistant tumors. There is a continuous need for genetic and biologic markers for the diverse clinical phenotypes observed in neuroblastoma patients. One of the known markers in neuroblastoma is expression of the CXCR4 chemokine receptor. CXCR4 expression correlates with high-stage disease, and the autocrine stimulation of CXCR4 by its ligand (CXCL12) was shown to be necessary for the survival of some neuroblastoma cells in vitro. However, the mechanisms responsible for activation of the CXCL12-CXCR4 autocrine pathway in neuroblastoma remain uncertain. Our previous findings suggest that Csk homologous kinase (CHK) is a physiological inhibitor of CXCR4 expression. Since CHK is highly expressed in neurons, we evaluated changes in CHK expression in human neuroblastoma. CHK protein expression was below detectable levels based on Western blot analyses in 13 out of 16 human neuroblastoma cell lines and in 6 out of 16 primary neuroblastoma tissues. When CHK expression was restored in IMR32 neuroblastoma cells by retrovirus-mediated cDNA transfer, diminished CXCR4 mRNA and protein levels were observed, as assessed by RT-PCR and flow cytometry analyses, respectively. Furthermore, exogenous expression of CHK markedly suppressed the mRNA levels and secretion of the CXCL12 chemokine from IMR32 cells as well as inhibited the growth rate of these cells. Taken together, our data strongly suggest that CHK is capable of inhibiting the CXCL12-CXCR4 pathway in neuroblastoma.
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PMID:Csk homologous kinase inhibits CXCL12-CXCR4 signaling in neuroblastoma. 1829 39

Chemokines and their receptors have emerged as pivotal regulators of tumour growth, progression, and metastasis. Here we review the current knowledge on chemokines and receptors likely involved in the development of metastasis of neuroectodermal tumours, with emphasis on neuroblastoma. In this respect, we discuss the controversial role of the CXCR4/CXCL12 axis in bone marrow localization of neuroblastoma cells. In addition, we focus on the ability of neuroblastoma-derived chemokines such as CCL2 and CX3CL1 to attract lymphoid cells to the tumour site. Finally, chemokine receptor and function in other neuroectodermal tumours of adulthood (i.e. melanoma and small cell lung cancer) are discussed.
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PMID:Chemokines in neuroectodermal tumour progression and metastasis. 1901 46


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