Genetic alterations in the chromosome 22q12 region associated with development of neuroectodermal tumors.
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Chromosome Mapping↗
Biomedical subjects
O Delattre
Publications and source records attributed to O Delattre.
DNA-binding and transcriptional activation properties of the EWS-FLI-1 fusion protein resulting from the t(11;22) translocation in Ewing sarcoma.
The 5' half of the EWS gene has recently been described to be fused to the 3' regions of genes encoding the DNA-binding domain of several transcriptional regulators, including ATF1, FLI-1, and ERG, in several human tumors. The most frequent occurrence of this situation results from the t(11;22)(q24;q12) chromosome translocation specific for Ewing sarcoma (ES) and related tumors which joins EWS sequences to the 3' half of FLI-1, which encodes a member of the Ets family of transcriptional regulators. We show here that this chimeric gene encodes an EWS-FLI-1 nuclear protein which binds DNA with the same sequence specificity as the wild-type parental FLI-1 protein. We further show that EWS-FLI-1 is an efficient sequence-specific transcriptional activator of model promoters containing FLI-1 (Ets)-binding sites, a property which is strictly dependent on the presence of its EWS domain. Comparison of the properties of the N-terminal activation domain of FLI-1 to those of the EWS domain of the fusion protein indicates that EWS-FLI-1 has altered transcriptional activation properties compared with FLI-1. These results suggest that EWS-FLI-1 contributes to the transformed phenotype of ES tumor cells by inducing the deregulated and/or unscheduled activation of genes normally responsive to FLI-1 or to other close members of the Ets family. ES and related tumors are characterized by an elevated level of c-myc expression. We show that EWS-FLI-1 is a transactivator of the c-myc promoter, suggesting that upregulation of c-myc expression is under control of EWS-FLI-1.
Amino Acid Sequence↗
Cloning of the entire FLI1 gene, disrupted by the Ewing's sarcoma translocation breakpoint on 11q24, in a yeast artificial chromosome.
FLI1 (Friend leukemia virus integration 1), a member of the Ets gene family, is disrupted on 11q24 by the Ewing's Sarcoma (ES) and Peripheral Neuroepithelioma (PNE) t(11;22)(q24;q12) translocation. ES and PNE are Primitive Neuroectodermal Tumors (PNETs) and the consistent translocation t(11;22)(q24;q12) can be used for differential diagnosis. In PNETs the 3' part of human FLI1 is translocated from 11q24 to 22q12, where it is juxtaposed to the 5' end of the Ewing's Sarcoma gene (EWS). A fusion transcript, resulting in a chimeric protein, is generated. Here, we present the isolation and detailed characterization of a 250-kb colinear YAC, B45C11, which encompasses the ES and PNE breakpoint on 11q24, as shown by FISSH on ES and PNE chromosomes and interphase nuclei. This YAC represents a new reagent for potential use in rapid differential diagnosis by FISSH on tumor biopsies and on paraffin embedded samples, particularly when DNA and/or RNA are not available for molecular analysis. YAC B45C11, which spans 250 kb of contiguous DNA around the ES and PNE breakpoint, contains the entire FLI1 gene. Three potential HpaII-tiny-fragment (HTF) islands are revealed within the YAC. One of these islands appears to be associated with the 5' end of FLI1, which extends over approximately 120 kb of DNA on 11q24. In addition, we demonstrate that YAC B45C11 contains other transcribed sequences in addition to FLI1, by "cross-species" Northern blot hybridizations, which suggests the presence of additional genes in the immediate vicinity of the ES breakpoint on 11q24.
Base Sequence↗
[Central retinal artery occlusion in surgery of the cervical vertebrae].
Retinal artery occlusion related to ocular compression is an uncommon but severe complication of general anaesthesia, most of the time results in blindness. We report a case of central retinal artery occlusion following spinal surgery. We discuss the mechanism of blindness and review the circumstances that may lead to this complication. Proper positioning of the head and avoidance of ocular compression will prevent the occurrence of retinal occlusion during general anaesthesia.
Anesthesia, General↗
[Reduction and osteosynthesis with pin fixation of wrist fractures. A comparative study between Kapandji's and Py's techniques].
MATERIAL: 62 fractures of the distal radius were treated by pin fixation: Kapandji's intra focal pinning in 28 cases (Group "K") and Py's elastic pinning in 34 cases (group "P"). The two groups were comparable as to the type of fractures (Castaing classification). Theoretical principles were analyzed and compared. RESULTS: Final radiographic results showed the same proportion (75 per cent) of anatomic reduction in both groups. There were 21.4 per cent (6/28) hyporeductions in group K, and 23.5 per cent (8/34) hypereducations in group P. Hyporeduction was moderate with good functional results. Hypereduction in group P was often associated with bad functional results, 5 out of the 6 bad results of all the cases. The functional result, with a follow up of 7 months (4 to 10), was 76 per cent of excellent and good results, 85 per cent in group K, 70 per cent in group P. DISCUSSION: Kapandji's technique seemed more reliable than Py's technique. We propose a technical variation to minimize hyporeduction in Kapandji's technic: increasing the pin's angulation. CONCLUSION: Py's technic conserves one indication: intra operative failure of Kapandji's technique in very osteoporotic bone.
Adolescent↗
Prospective evaluation of Nmyc amplification and deletion of the short arm of chromosome 1 in neuroblastoma tumours: a single institution study.
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Chromosome Deletion↗
Loss of the putative tumor suppressor-gene locus 1p36 as investigated by a PCR-assay and N-myc amplification in 48 neuroblastomas: results of the German Neuroblastoma Study Group.
48 primary neuroblastomas have been examined for an amplified N-myc and loss of the putative tumor suppressor-gene locus 1p36 by loss of heterozygosity studies (LOH 1p36). In 25% of these tumors N-myc amplification and/or a LOH 1p36 was detected, and these patients had a bad prognostic clinical outcome. 75% of the tumors neither had an amplified N-myc nor a LOH 1p36, and these patients had a much better prognosis. Thus, tumor genetic changes can subdivide two types of neuroblastoma with profound different clinical behavior. Detection of these genetic changes at diagnosis could help in front-line risk adapted therapy stratifications in neuroblastoma.
Base Sequence↗
Ewing sarcoma 11;22 translocation produces a chimeric transcription factor that requires the DNA-binding domain encoded by FLI1 for transformation.
The 11;22 chromosomal translocation specifically linked to Ewing sarcoma and primitive neuroectodermal tumor results in a chimeric molecule fusing the amino-terminal-encoding portion of the EWS gene to the carboxyl-terminal DNA-binding domain encoded by the FLI1 gene. We have isolated a fourth EWS-FLI1 fusion cDNA that is structurally distinct from the three forms previously described. To determine the transforming activity of this gene, alternative forms of the EWS-FLI1 fusion were transduced into NIH 3T3 cells. Cells expressing either type 1 or type 4 fusion constructs formed foci in culture and colonies in soft agar, indicating that EWS-FLI1 is a transforming gene. EWS-FLI1 deletion mutants were created to map functionally the critical regions within the chimera. Deletion of either the EWS domain or the FLI1 corresponding to the DNA-binding domain totally abrogated the ability for EWS-FLI1 to transform 3T3 cells. These data indicate that the oncogenic effect of the 11;22 translocation is caused by the formation of a chimeric transcription factor. Formation of chimeric transcription factors has now been demonstrated to promote tumors of both neuroectodermal and hematopoietic origin, suggesting that this may be a common mechanism in human carcinogenesis.
Amino Acid Sequence↗
Regional fine mapping of the beta crystallin genes on chromosome 22 excludes these genes as physically linked markers for neurofibromatosis type 2.
Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disease, characterized by the development of bilateral vestibular schwannomas. The NF2 gene has been assigned to chromosome 22. Cataract and other eye abnormalities are frequently seen in NF2 patients. The specific association of eye abnormalities and NF2 might be caused by a genetic change on chromosome 22 that affects both the NF2 gene and a physically linked crystallin gene. In order to test this hypothesis, we regionally localized the known crystallin genes (i.e. CRYBB2, CRYBB2P1, CRYBB3, and CRYBA4) on chromosome 22. Crystallin gene-specific probes were hybridized to an extended panel of human x rodent somatic cell hybrids containing various portions of chromosome 22. It was found that all crystallin genes map to a very small region on chromosome 22 that is physically separate from the NF2 gene region by at least 160 kb of DNA. In addition, we found that the beta B crystallin genes (CRYBB2, CRYBB2P1, and CRYBB3) are clustered on a 300 kb SacII fragment and that the beta A4 crystallin gene (CRYBA4) is not part of this cluster. We conclude that the ocular manifestations in many NF2 patients are probably not the primary consequence of rearrangements on chromosome 22 that involve both the NF2 gene and a nearby beta crystallin gene.
Animals↗
The genes for oncostatin M (OSM) and leukemia inhibitory factor (LIF) are tightly linked on human chromosome 22.
Oncostatin M (OSM) and leukemia inhibitory factor (LIF) are members of a family of cytokines that regulate the proliferation and differentiation of a variety of cell types. In this report, cDNA probes specific for OSM and LIF were hybridized to DNA from somatic cell hybrids containing defined regions of human chromosome 22, and the gene for human OSM was found to segregate with that of LIF. Southern analysis of high-molecular-weight DNA that had been digested with rare-cutting restriction enzymes and analyzed by pulsed-field gel electrophoresis showed identical hybridization patterns with both probes. The probes also identified common cosmid clones on high-density cosmid filters prepared from chromosome 22-specific flow-sorted cosmid libraries. Restriction and Southern analyses of six cosmid clones established a contig of approximately 100 kb surrounding the genes for OSM and LIF. The OSM and LIF genes are tandemly arranged in the same transcriptional orientation separated by approximately 10 kb. The direction of gene transcription is telomeric to centromeric, with the OSM gene located upstream of the LIF gene. Our studies define a new gene cluster on chromosome 22 and provide strong evidence that OSM and LIF have resulted from duplication of a common ancestral gene.
Animals↗
Mapping of human gamma-glutamyl transpeptidase genes on chromosome 22 and other human autosomes.
gamma-Glutamyl transpeptidase (GGT; EC 2.3.2.2) is a membrane-associated enzyme that plays a role in the metabolism of glutathione and in the transpeptidation of amino acids; changes in GGT activity may reflect preneoplastic or toxic conditions in the liver or kidney. In contrast to the rat, in which GGT is represented by a single gene, at least four GGT genomic sequences have been identified in man and two of these have been localized to two distinct regions of chromosome 22. To characterize this gene/pseudogene family further, we have used somatic cell hybrids to map GGT by hybridization with probes from a human kidney GGT cDNA clone and by amplification of 3' GGT sequence by PCR. We clearly map three GGT loci to chromosome 22: two loci between the centromere and the breakpoint cluster region (BCR) gene and one locus telomeric to the BCR gene. In addition, we have been able to identify GGT-related sequences on chromosomes 18, 19, and 20.
Animals↗
Isolation and mapping of 45 NotI linking clones to chromosome 22.
Fifty-nine NotI linking clones have been isolated from a flow-sorted chromosome 22 cosmid library and mapped using fluorescence in situ hybridization and/or a panel of somatic cell hybrids. Fourteen clones map to the short arm of chromosome 22, 31 to the long arm, and 9 to other chromosomes; 5 clones could not be unambiguously mapped. To identify potentially informative genetic markers, the chromosome 22 clones were screened for poly(CA) sequences; 24 positively hybridizing clones, 10 on the long arm and 14 on the short arm, were identified. These clones will be useful for constructing a long-range restriction map of chromosome 22 and may facilitate the cloning of chromosome 22 genes.
Base Sequence↗
Subregional physical mapping of an alpha B-crystallin sequence and of a new expressed sequence D11S877E to human 11q.
We report the regional assignment on Chromosome (Chr) 11q of two cDNA clones selected as sequences expressed in mature kidney and not expressed in Wilms' tumor. Clone T70 was identified as an alpha B-crystallin sequence (CRYA2). CRYA2 has previously been mapped to 11q22.3-23.1 by in situ hybridization. Clone 6.2 represents a new gene expressed in adult and fetal kidney, pancreas, and liver. In order to map sequences corresponding to clone 6.2 and to physically define the boundaries of the localization of CRYA2, we used somatic cell hybrids carrying either different human chromosomes or Chr 11 segments and a cell line established from a patient with an interstitial deletion of region 11q14.3-q22.1. We showed that CRYA2 lies proximal to the 11q23.2 breakpoint defined by the constitutional t(11;22) and distal to the 11q22.1 breakpoint (between D11S388 and D11S35) of a constitutional interstitial deletion. This is in agreement with previous data obtained by in situ hybridization and provides proximal and distal physical benchmarks for this localization. Clone 6.2-related sequence (D11S877E) was assigned to region 11q23.2-q24.2 defined by the breakpoints of the constitutional t(11;22) and of the Ewing's sarcoma neuroepithelioma t(11;22).
Animals↗
Genomic structure of the EWS gene and its relationship to EWSR1, a site of tumor-associated chromosome translocation.
The EWS gene has been identified based on its location at the chromosome 22 breakpoint of the t(11;22)(q24;q12) translocation that characterizes Ewing sarcoma and related neuroectodermal tumors. The EWS gene spans about 40 kb of DNA and is encoded by 17 exons. The nucleotide sequence of the exons is identical to that of the previously described cDNA. The first 7 exons encode the N-terminal domain of EWS, which consists of a repeated degenerated polypeptide of 7 to 12 residues rich in tyrosine, serine, threonine, glycine, and glutamine. Exons 11, 12, and 13 encode the putative RNA binding domain. The three glycine- and arginine-rich motifs of the gene are mainly encoded by exons 8-9, 14, and 16. The DNA sequence in the 5' region of the gene has features of a CpG-rich island and lacks canonical promoter elements, such as TATA and CCAAT consensus sequences. Positions of the chromosome 22 breakpoints were determined for 19 Ewing tumors. They were localized in introns 7 or 8 in 18 cases and in intron 10 in 1 case.
Amino Acid Sequence↗
EWS and ATF-1 gene fusion induced by t(12;22) translocation in malignant melanoma of soft parts.
The genes involved in the t(12;22)(q13;q12) translocation found recurrently in malignant melanoma of soft parts have been characterized and shown to form, in four cases studied, hybrid transcripts. The deduced chimaeric protein encoded by the der(22) chromosome consists of the N-terminal domain of EWS linked to the bZIP domain of ATF-1, a transcription factor which may normally be regulated by cAMP. ATF-1 has not previously been implicated in oncogenesis. EWS was first identified as forming a hybrid transcript in Ewing's sarcoma, which links its N-terminal domain to the DNA binding domain of the FLI-1 gene. Thus the oncogenic conversion of EWS follows a common scheme of activation, exchanging its putative RNA binding domain with different DNA binding domains that appear to be tumour-specific.
Activating Transcription Factor 1↗
Dinucleotide repeat polymorphism at the D22S268 locus.
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Alleles↗
Isolation of cosmids and fetal brain cDNAs from the proximal long arm of human chromosome 22.
The proximal portion of human chromosome 22q appears to carry genes implicated in the pathogenesis of various developmental disorders, including the cat eye syndrome (CES) and the DiGeorge syndrome (DGS). A cosmid library was prepared from a radiation hybrid selected for its content in chromosome 22 fragments. A large fraction of cosmids containing human DNA were found to derive from the juxtacentromeric region of chromosome 22, as shown by fluorescence in situ hybridization (FISH) performed using individual cosmids or cosmid pools as probes. Finer mapping was obtained for individual cosmids by hybridization to a somatic cell hybrid mapping panel which splits the long arm of the chromosome into 14 bins numbered 1 to 14 from the centromere to the telomere. Of the 10 cosmids mapped, eight belonged to group 1, the other two to group 14, in agreement with FISH data. Rare endonuclease sites and fragments conserved between species were searched in single cosmids, resulting in the selection of seven cosmid fragments which were used to screen a human fetal brain cDNA library. Three cDNAs were identified, encoded from two chromosome 22 genes which appeared to be novel, as determined from partial end sequence and comparison with the database entries. Fine localization of the 30.9 cDNA indicated that the corresponding gene was located in a segment of proximal 22q overlapping with the critical DGS region.
Animals↗
Germline deletion in a neurofibromatosis type 2 kindred inactivates the NF2 gene and a candidate meningioma locus.
Neurofibromatosis type 2 (NF2) is an autosomal dominant disease which predisposes to the development of schwannomas, meningiomas, ependymomas, and juvenile cataracts. The NF2 gene (NF2) has recently been isolated and maps to chromosome 22q12 between the loci D22S212 and D22S32. Deletion studies in sporadic and NF2 associated schwannomas and meningiomas, and the presence of inactivating mutations in NF2 in patients suggest that it acts as a tumor suppressor gene. A candidate meningioma gene (MEN) has also been isolated from the same interval. A new highly polymorphic (CA)n marker, D22S268, which maps very near to NF2, has allowed us to identify a kindred with three living affected individuals, where the disease is presumably caused by a large germline deletion. Fluorescence in situ hybridization and pulsed field gel electrophoresis confirm the presence of a 700kb deletion which includes the neurofilament heavy chain subunit gene locus (NEFH), D22S268, NF2 and the putative MEN gene. The absence of meningiomas in this pedigree raises doubts as to the existence of a separate MEN locus in this region. These results support the hypothesis that NF2 results from the inactivation of a tumor suppressor gene on chromosome 22q.
Cells, Cultured↗