Isabelle Joubert

Bio: Isabelle Joubert is an academic researcher from Curie Institute. The author has contributed to research in topics: Chromosomal translocation & Chromosome 22. The author has an hindex of 2, co-authored 2 publications receiving 1875 citations.

Gene fusion with an ETS DNA-binding domain caused by chromosome translocation in human tumours

Abstract: Ewing's sarcoma and related subtypes of primitive neuroectodermal tumours share a recurrent and specific t(11;22) (q24;q12) chromosome translocation, the breakpoints of which have recently been cloned. Phylogenetically conserved restriction fragments in the vicinity of EWSR1 and EWSR2, the genomic regions where the breakpoints of chromosome 22 and chromosome 11 are, respectively, have allowed identification of transcribed sequences from these regions and has indicated that a hybrid transcript might be generated by the translocation. Here we use these fragments to screen human complementary DNA libraries to show that the translocation alters the open reading frame of an expressed gene on chromosome 22 gene by substituting a sequence encoding a putative RNA-binding domain for that of the DNA-binding domain of the human homologue of murine Fli-1.

Cloning and characterization of the Ewing's sarcoma and peripheral neuroepithelioma t(11;22) translocation breakpoints.

Abstract: Ewing's sarcoma (ES) and peripheral neuroepithelioma (PN) are related tumors, possibly of neural crest origin, which are cytogenetically characterized by the specific translocation t(11;22)(q24;q 12). The cos5 locus, previously identified in the vicinity of the chromosome 22 breakpoint of this translocation, was shown by in situ hybridization on interphase nuclei to lie between VIIIF2 and LIF, two loci located on either side of the breakpoint and at a distance of less than 2,000 kb. The progressive expansion of this locus by chromosome walking led to the construction of a 300 kb contig, which finally crossed the breakpoint. The subsequent cloning of the two translocation junction fragments of a PN, followed by the molecular characterization of the translocation breakpoints of 20 ES and PN, showed that most chromosome 22 breakpoints are clustered within a small, 2 kb region. In contrast, the chromosome 11 breakpoints are scattered over a region of at least 40 kb. The translocation leads to the synthesis of a chimeric transcript that links sequences from chromosomes 22 and 11. Finally, no evidence was found of any specific difference in the position of ES and PN translocation breakpoints.

Revisions of the international criteria for neuroblastoma diagnosis, staging, and response to treatment.

Abstract: PURPOSE AND METHODS: Based on preliminary experience, there was a need for modifications and clarifications in the International Neuroblastoma Staging System (INSS) and International Neuroblastoma Response Criteria (INRC). In 1988, a proposal was made to establish an internationally accepted staging system for neuroblastoma, as well as consistent criteria for confirming the diagnosis and determining response to therapy (Brodeur GM, et al: J Clin Oncol 6:1874-1881, 1988). A meeting was held to review experience with the INSS and INRC and to revise or clarify the language and intent of the originally proposed criteria. Substantial changes included a redefinition of the midline, restrictions on age and bone marrow involvement for stage 4S, and the recommendation that meta-iodobenzylguanidine (MIBG) scanning be implemented for evaluating the extent of disease. Other modifications and clarifications of the INSS and INRC are presented. In addition, the criteria for the diagnosis of neuroblastoma were modified. ...

Conserved structures and diversity of functions of RNA-binding proteins.

Abstract: In eukaryotic cells, a multitude of RNA-binding proteins play key roles in the posttranscriptional regulation of gene expression. Characterization of these proteins has led to the identification of several RNA-binding motifs, and recent experiments have begun to illustrate how several of them bind RNA. The significance of these interactions is reflected in the recent discoveries that several human and other vertebrate genetic disorders are caused by aberrant expression of RNA-binding proteins. The major RNA-binding motifs are described and examples of how they may function are given.

Chromosomal translocations in human cancer.

Abstract: Chromosomal abnormalities in tumours were recognized at the end of the last century but their significance has only recently become clear. Distinct translocations in leukaemias and in solid tumours lead to the activation of proto-oncogene products or, more commonly, creation of tumour-specific fusion proteins. The proteins in both categories are often transcription factors and thus disruption of transcriptional control plays a major role in the aetiology of cancer. Fusion proteins formed after chromosomal translocations are common in a range of tumour types; these are unique tumour antigens and are therefore potential targets for therapy design.

Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2

Abstract: Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease predisposing carriers to develop nervous system tumours. To identify the genetic defect, the region between two flanking polymorphic markers on chromosome 22 was cloned and several genes identified. One is the site of germ-line mutations in NF2 patients and of somatic mutations in NF2-related tumours. Its deduced product has homology with proteins at the plasma membrane and cytoskeleton interface, a previously unknown site of action of tumour suppressor genes in humans.