Publications by authors named "Michele El Atifi"

Our objective was to study NMR relaxometry of glioma invasion/migration at very low field (<2 mT) by fast-field-cycling NMR (FFC-NMR) and to decipher the pathophysiological processes of glioma that are responsible for relaxation changes in order to open a new diagnostic method that can be extended to imaging. The phenotypes of two new glioma mouse models, Glio6 and Glio96, were characterized by T -MRI, HE histology, Ki-67 immunohistochemistry (IHC) and CXCR4 RT-qPCR, and were compared with the U87 model. R dispersions of glioma tissues were acquired at low field (0.

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  • Macrophages are versatile immune cells that respond to various environmental signals, influencing their roles in both maintaining tissue health and contributing to diseases.
  • The study aimed to create a detailed molecular profile of different macrophage activation states, identifying over 5,100 proteins through advanced techniques.
  • Environmental oxygen levels significantly impact macrophage polarization, leading to the discovery of specific markers and highlighting oxygen as a crucial factor in understanding macrophage functions.
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  • The study investigates whether duplication of the ARID1A gene is linked to a new syndrome, analyzing four patients with a specific microduplication on chromosome 1p36.11.
  • Researchers used advanced techniques, including RNA sequencing and cell cycle analysis, to understand the effects of this genetic duplication on patient cells.
  • Findings indicate that the patients exhibited similar symptoms, such as intellectual disability and microcephaly, with altered gene expression related to these conditions, suggesting a significant link between ARID1A gene duplication and developmental disorders.
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  • U937 cells were successfully labelled with a special nanoparticle without affecting their viability and were tested to develop a method for measuring cell concentration through relaxation rate metrics.
  • The study validated this method in a mouse model, showing that MRI can accurately map concentrations of labelled U937 cells over time, providing a reliable way to monitor therapeutic cell distribution.
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Monitoring glioma cell infiltration in the brain is critical for diagnosis and therapy. Using a new glioma Glio6 mouse model derived from human stem cells we show how diffusion tensor imaging (DTI) may predict glioma cell migration/invasion. In vivo multiparametric MRI was performed at one, two and three months of Glio6 glioma growth (Glio6 (n = 6), sham (n = 3)).

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Purpose: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood.

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Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or the internal segment of the globus pallidus (GPi) has been established as a highly effective symptomatic therapy for Parkinson's disease (PD). An intriguing biological aspect related to the DBS procedure is that a temporary contact establishes between surgical instruments and the surrounding brain tissue. In this exploratory study, we took advantage of this unique context to harvest brain material adhering to the stylet routinely used during surgery, and to examine the biological value of these samples, here referred to as "brain tissue imprints" (BTIs).

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1,25 Dihydroxyvitamin D3 (1,25D) is a hormone produced from vitamin D through two hydroxylating steps catalyzed successively in the liver by the vitamin D 25-hydroxylase Cyp2R1 and in the kidney by the 25-hydroxyvitamin D3 1α-hydroxylase Cyp27B1. 1,25D behaves like a steroid hormone. It regulates gene transcription by interacting with a nuclear receptor named vitamin D receptor (VDR) for the vitamin D receptor.

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Synchrotron microbeam radiation therapy (MRT) relies on the spatial fractionation of a synchrotron beam into parallel micron-wide beams allowing deposition of hectogray doses. MRT controls the intracranial tumor growth in rodent models while sparing normal brain tissues. Our aim was to identify the early biological processes underlying the differential effect of MRT on tumor and normal brain tissues.

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Synchrotron Microbeam Radiation Therapy (MRT) relies on the spatial fractionation of the synchrotron photon beam into parallel micro-beams applying several hundred of grays in their paths. Several works have reported the therapeutic interest of the radiotherapy modality at preclinical level, but biological mechanisms responsible for the described efficacy are not fully understood to date. The aim of this study was to identify the early transcriptomic responses of normal brain and glioma tissue in rats after MRT irradiation (400Gy).

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Most of our knowledge regarding glioma cell biology comes from cell culture experiments. For many years the standards for glioma cell culture were the use of cell lines cultured in the presence of serum and 20 % O2. However, in vivo, normoxia in many brain areas is in close to 3 % O2.

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Seasonal or chronic vitamin D deficiency and/or insufficiency is highly prevalent in the human population. Receptors for 1,25-dihydroxyvitamin D3, the hormonal metabolite of vitamin D, are found throughout the brain. To provide further information on the role of this hormone on brain function, we analyzed the transcriptomic profiles of mixed neuron-glial cell cultures in response to 1,25-dihydroxyvitamin D3.

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Background: Globozoospermia is a male infertility phenotype characterized by the presence in the ejaculate of near 100% acrosomeless round-headed spermatozoa with normal chromosomal content. Following intracytoplasmic sperm injection (ICSI) these spermatozoa give a poor fertilization rate and embryonic development. We showed previously that most patients have a 200 kb homozygous deletion, which includes DPY19L2 whole coding sequence.

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Gliomas such as oligodendrogliomas (ODG) and glioblastomas (GBM) are brain tumours with different clinical outcomes. Histology-based classification of these tumour types is often difficult. Therefore the first aim of this study was to gain microRNA data that can be used as reliable signatures of oligodendrogliomas and glioblastomas.

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Tumor invasion or infiltration of adjacent tissues is the source of clinical challenges in diagnosis as well as prevention and treatment. Among brain tumors, infiltration of the adjacent tissues with diverse pleiotropic mechanisms is frequently encountered in benign meningiomas. We assessed whether a multiparametric analysis of meningiomas based on data from both clinical observations and molecular analyses could provide a consistent and accurate appraisal of invasive and infiltrative phenotypes and help determine the diagnosis of these tumors.

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Under standard culture conditions, tumor cells are exposed to 20% O(2), whereas the mean tumor oxygen levels within the tumor are much lower. We demonstrate, using low-passaged human tumor cell cultures established from glioma, that a reduction in the oxygen level in these cell cultures dramatically increases the percentage of CD133 expressing cells.

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Objective: The roles of phosphatidylinositol 3 (PI3K) and mitogen-activated protein kinases (MAPK) have been widely studied in terms of the differentiation process induced by several drugs (phorbol ester, vitamin D-3, retinoic acid, etc.), but their exact functions in leukemic cells' phenotype and their potential therapeutic role remain incompletely clarified.

Materials And Methods: In order to investigate this query, leukemia cells were cultured in presence of kinase inhibitors (KIs).

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Objective: Investigating whether extracellular factors are possible actors in tumoral progression in bladder carcinoma.

Methods: RT112/G2 bladder tumour cells were grown in presence of TGFbeta and analysed by immunological and cDNA microarray techniques.

Results: TGFbeta inhibited cell proliferation, reduced TNFalpha- and IFNgamma-induced apoptosis by decreasing TNFalpha-RI and IFNgamma-R antigen expression.

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Background: TNFα and IFNγ, two main cytokines secreted in the urine of bladder cancer patients after Bacillus Calmette Guerin immunotherapy (BCG therapy), exert various responses ranging from growth arrest, apoptosis, phenotypic changes and differentiation.

Materials And Methods: To identify their transcriptional and translational targets, the highly sensitive bladder cancer cell line (RT112) was treated for 24 hours with increasing doses of IFNγ or TNFα and analyzed for cellular and molecular changes using a cDNA microarray technique (Transcriptome) containing 800 genes.

Results: High doses (>10 ng/ml) induced an apoptotic cell death, whereas low doses (<5 ng/ml) induced a survival program.

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