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Publications (2)36.28 Total impact

  • Article: Knock down of HIF-1α in glioma cells reduces migration in vitro and invasion in vivo and impairs their ability to form tumor spheres
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    ABSTRACT: Abstract Background Glioblastoma (GBM) is the most common and malignant primary intracranial human neoplasm. GBMs are characterized by the presence of extensive areas of necrosis and hypoxia. Hypoxia and its master regulator, hypoxia inducible factor 1 (HIF-1) play a key role in glioma invasion. Results To further elucidate the functional role of HIF-1α in glioma cell migration in vitro and in invasion in vivo , we used a shRNA approach to knock down HIF-1α expression complemented with genome-wide expression profiling, performed in both normoxic and hypoxic conditions. Our data show that knock down of HIF-1α in glioma cells significantly impairs their migration in vitro as well as their ability to invade into the brain parenchyma in vivo . Next, we assessed the role that HIF-1α plays in maintaining the characteristics of cancer stem cells (CSCs). By using the tumor sphere forming assay, we demonstrate that HIF-1α plays a role in the survival and self-renewal potential of CSCs. Finally, expression profiling experiments in glioma cells provided detailed insight into a broad range of specific biological pathways and processes downstream of HIF-1α. We discuss the role of these processes in the migratory and invasive properties, as well as the stem cell biology of glioblastomas Conclusions Our data show that knock down of HIF-1α in human and murine glioma cells impairs their migration in vitro and their invasion in vivo . In addition, our data suggest that HIF-1α plays a role in the survival and self-renewal potential of CSCs and identify genes that might further elucidate the role of HIF-1α in tumor migration, invasion and stem cell biology.
    Molecular Cancer. 01/2010;
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    Article: CCR7 signalling as an essential regulator of CNS infiltration in T-cell leukaemia.
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    ABSTRACT: T-cell acute lymphoblastic leukaemia (T-ALL) is a blood malignancy afflicting mainly children and adolescents. T-ALL patients present at diagnosis with increased white cell counts and hepatosplenomegaly, and are at an increased risk of central nervous system (CNS) relapse. For that reason, T-ALL patients usually receive cranial irradiation in addition to intensified intrathecal chemotherapy. The marked increase in survival is thought to be worth the considerable side-effects associated with this therapy. Such complications include secondary tumours, neurocognitive deficits, endocrine disorders and growth impairment. Little is known about the mechanism of leukaemic cell infiltration of the CNS, despite its clinical importance. Here we show, using T-ALL animal modelling and gene-expression profiling, that the chemokine receptor CCR7 (ref. 5) is the essential adhesion signal required for the targeting of leukaemic T-cells into the CNS. Ccr7 gene expression is controlled by the activity of the T-ALL oncogene Notch1 and is expressed in human tumours carrying Notch1-activating mutations. Silencing of either CCR7 or its chemokine ligand CCL19 (ref. 6) in an animal model of T-ALL specifically inhibits CNS infiltration. Furthermore, murine CNS-targeting by human T-ALL cells depends on their ability to express CCR7. These studies identify a single chemokine-receptor interaction as a CNS 'entry' signal, and open the way for future pharmacological targeting. Targeted inhibition of CNS involvement in T-ALL could potentially decrease the intensity of CNS-targeted therapy, thus reducing its associated short- and long-term complications.
    Nature 07/2009; 459(7249):1000-4. · 36.28 Impact Factor