Raphael Sandaltzopoulos

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Functional nuclei and mitotic spindles are shown to assemble around DNA-coated beads incubated in Xenopus egg extracts. Bipolar spindles assemble in the absence of centrosomes and kinetochores, indicating that bipolarity is an intrinsic property of microtubules assembling around chromatin in a mitotic cytoplasm. Microtubules nucleated at dispersed sites(More)
MicroRNAs (miRNAs) are an abundant class of small noncoding RNAs that function as negative gene regulators. miRNA deregulation is involved in the initiation and progression of human cancer; however, the underlying mechanism and its contributions to genome-wide transcriptional changes in cancer are still largely unknown. We studied miRNA deregulation in(More)
Tumor growth results in hypoxia. Understanding the mechanisms of gene expression reprogramming under hypoxia may provide important clues to cancer pathogenesis. We studied miRNA genes that are regulated by hypoxia in ovarian cancer cell lines by TaqMan miRNA assay containing 157 mature miRNAs. MiR-210 was the most prominent miRNA consistently stimulated(More)
NURF is an ISWI complex of four proteins that uses the energy of ATP hydrolysis to catalyze nucleosome sliding. Three NURF components have been identified previously. We have cloned cDNA encoding the largest NURF subunit, revealing a 301 kDa polypeptide (NURF301) that shares structural motifs with ACF1. We have reconstituted full and partial NURF complexes(More)
Drosophila NURF is an ATP-dependent chromatin remodeling complex that contains ISWI, a member of the SWI2/SNF2 family of ATPases. We demonstrate that NURF catalyzes the bidirectional redistribution of mononucleosomes reconstituted on hsp70 promoter DNA. In the presence of NURF, nucleosomes adopt one predominant position from an ensemble of possible(More)
PURPOSE This study aimed to identify novel ovarian cancer biomarkers and potential therapeutic targets through molecular analysis of tumor vascular cells. METHODS Immunohistochemistry-guided laser-capture microdissection and genome-wide transcriptional profiling were used to identify genes that were differentially expressed between vascular cells from(More)
The heterodimeric transcription factor HIF-1 (hypoxia-inducible factor 1) represents the key mediator of hypoxia response. HIF-1 controls numerous genes of pivotal importance for cellular metabolism, angiogenesis, cell cycle regulation and inhibition of apoptosis. HIF-1 overexpression and enhanced transcriptional activity are linked to tumour initiation and(More)
Chromatin reconstituted in an extract from preblastoderm Drosophila embryos represses transcription by RNA polymerase II. We have assembled regularly spaced nucleosomes on DNA attached to paramagnetic beads enabling the efficient purification of chromatin templates for transcription studies. We have used diagnostic salt extractions to establish that(More)
The chromatin structure at the Drosophila hsp26 promoter in vivo is characterized by two DNase I-hypersensitive (DH) sites harboring regulatory elements. Proximal and distal DH sites are separated by a positioned nucleosome. To study the contribution of transcription factors to the establishment of this specific chromatin configuration we assembled(More)
Prothymosin alpha (ProTalpha) is an abundant acidic nuclear protein that may be involved in cell proliferation. In our search for its cellular partners, we have recently found that ProTalpha binds to linker histone H1. We now provide further evidence for the physiological relevance of this interaction by immunoisolation of a histone H1-ProTalpha complex(More)