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Algiers, Algeria

Bourouba M.,University of Science and Technology Houari Boumediene | Bourouba M.,Boston University | Zergoun A.-A.,University of Science and Technology Houari Boumediene | Maffei J.S.,Boston University | And 6 more authors.
Cytokine | Year: 2015

Tumor necrosis factor (TNFα) is a pro-inflammatory cytokine which mediates via nitric oxide (NO) several carcinogenic processes. Increasing evidences suggest that NO promotes inflammation induced growth of nasopharyngeal carcinoma (NPC). In patients, TNFα synthesis associates with poor survival. To explore the effect of the cytokine on NO production and NOS2 dependent NPC growth, NO2- (nitrite) producing cells in patients were analyzed in vitro. We observed that patients' monocytes/macrophages (Mo/Ma) and primary tumor biopsies synthesized significant amounts of NO2-. Interestingly, tumor explants derived NO2- levels were more important in elderly patients in comparison with juveniles. Endogenous TNFα neutralization with an anti-TNFα monoclonal antibody (mAb) successfully inhibited NO2- synthesis by blood mononuclear cells and tumor explants. Recombinant TNFα (rTNFα) enhanced NO2- synthesis and C666-1 NPC cell proliferation. NOS2 selective inhibition (1400W) and TNFα antagonization with an anti-TNFα mAb potently inhibited rTNFα induced C666-1 proliferation and NO2- production. Importantly, primary tumors treated with the anti-TNFα mAb also displayed reduced proliferation index (Ki67). Altogether, our results define monocytes/macrophages and the primary tumor as major sources of circulating NO2- in NPC patients and support the idea that antibody dependent inhibition of the TNFα/NOS2 pathway may alter NPC tumor growth. © 2015 Elsevier Ltd. Source

Belkhelfa M.,Laboratory of Cellular and Molecular Biology | Rafa H.,Laboratory of Cellular and Molecular Biology | Medjeber O.,Laboratory of Cellular and Molecular Biology | Arroul-Lammali A.,Laboratory of Cellular and Molecular Biology | And 7 more authors.
Journal of Interferon and Cytokine Research | Year: 2014

Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n = 25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway. © Mary Ann Liebert, Inc. Source

Zergoun A.-A.,University of Science and Technology Houari Boumediene | Zebboudj A.,University of Science and Technology Houari Boumediene | Sellam S.L.,University of Science and Technology Houari Boumediene | Kariche N.,University of Science and Technology Houari Boumediene | And 9 more authors.
Tumor Biology | Year: 2015

The role of nitric oxide (NO)· in the development of the metastatic properties of nasopharyngeal carcinoma (NPC) is not fully understood. Previous studies proposed that interleukin-6 (IL-6) would act as regulator of matrix metalloprotease activation in NPC. Recently, we showed that (NO)· was a critical mediator of tumor growth in patients. The aim of this study was to determine the implication of IL-6 in the progression of NPC pathology via metalloprotease (MMP) activation and their possible correlation with (NO)· production. We observed a significant increase in IL-6 and nitrite (NO2 −) synthesis in patients (n = 17) as well as a strong expression of IL-6 and nitric oxide synthase 2 (NOS2) in the analyzed tumors (n = 8). In patients’ plasma, a negative correlation associated IL-6 with circulating nitrites (r = −0.33). A negative correlation associated the H-scores of these signals in the tumors (r = −0.47). In patients’ plasma, nitrite synthesis was positively associated with MMP-9 activation (r = 0.45), pro-MMP-2 expression (r = 0.37), and negatively correlated with MMP-2 activation (r = −0.51). High nitrite levels was associated with better recurrence-free survival (RFS) (p = 0.02). Overall, our results suggest that the IL-6/NOS2 inflammatory signals are involved in the regulation of MMP-9- and MMP-2-dependent metastatic activity and that high circulating nitrite levels in NPC patients may constitute a prognostic predictor for survival. © 2015 International Society of Oncology and BioMarkers (ISOBM) Source

Behairi N.,University of Science and Technology Houari Boumediene | Belkhelfa M.,University of Science and Technology Houari Boumediene | Mesbah-Amroun H.,University of Science and Technology Houari Boumediene | Rafa H.,University of Science and Technology Houari Boumediene | And 3 more authors.
NeuroImmunoModulation | Year: 2015

Background: Alzheimer's disease (AD), the most common form of dementia in the elderly, is a neurodegenerative disorder associated with a complex pathophysiology. It is accepted that inflammation contributes to the pathogenesis of AD. All-trans-retinoic acid (ATRA) is a bioactive derivative of Vitamin A that has shown immunomodulatory effects in many immune disorders. Objectives: In our study, we aimed to investigate in vitro immunomodulatory effects of ATRA on inducible nitric oxide synthase (iNOS) expression and interleukin-17A production during AD. Methods: Peripheral blood mononuclear cells (PBMCs) isolated from 30 Algerian AD patients and 14 age-matched nondemented controls were treated (or not) with ATRA. Production of NO and IL-17A in culture media was measured by the modified Griess method and enzyme-linked immunosorbent assay, respectively. Expression of iNOS in PBMCs was examined by fluorescence immunostaining. Results: Our results showed higher spontaneous in vitro production of NO related to overexpression of iNOS in AD patients compared to controls. Remarkably, ATRA treatment showed an important downregulatory effect on NO production and iNOS expression in patients. This effect was associated with a reduction in IL-17A production and increased IL-10 release. Conclusions: Taken together, our results indicate that ATRA exerts anti-inflammatory effects in AD. Furthermore, ATRA represents a promising tool for monitoring inflammatory responses associated with disease progression. © 2015 S. Karger AG, Basel. Source

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