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C Turc-Carel

Publications and source records attributed to C Turc-Carel.

At least 37 records · Page 2Linked to original sources
PubMed1997

Multiple chromosomal mechanisms generate an EWS/FLI1 or an EWS/ERG fusion gene in Ewing tumors.

The t(11;22)(q24;q12) translocation is found in about 85% of Ewing tumors and leads in all cases to an EWS/FLI1 fusion gene. In a few instances, complex translocations, involving chromosomes 11, 22 and a third chromosome or other variant translocations not involving chromosome 11 also have been reported. These rearrangements generate an active fusion gene between the EWS gene and either the human FLI1 gene or other members of the ETS gene family: the ERG gene localized in band 21q22.2, the ETV1 gene localized in band 7p22, or the E1AF gene localized in band 17q12. Using fluorescence in situ hybridization (FISH) on interphase nuclei or metaphases, we report here the characterization of particular karyotypes in Ewing tumors, namely a complex t(2;11;22) translocation, a variant t(12;22) translocation, and one Ewing tumor without specific rearrangements but with an EWS/ERG fusion gene demonstrated by molecular analysis. These molecular cytogenetic methods allowed us (1) to precisely localize the genomic breakpoints within-EWSR1 and EWSR2 and to identify the chromosome carrying the fusion gene; (2) to determine the nature of events generating the fusion genes; (3) to demonstrate that some variant translocations represent masked complex translocations; and (4) to show that the generation of an EWS/ERG fusion gene cannot be obtained through a simple balanced translocation.

Chromosome Aberrations↗
PubMed1997

Deregulation of the platelet-derived growth factor B-chain gene via fusion with collagen gene COL1A1 in dermatofibrosarcoma protuberans and giant-cell fibroblastoma.

Dermatofibrosarcoma protuberans (DP), an infiltrative skin tumour of intermediate malignancy, presents specific features such as reciprocal translocations t(17;22)(q22;q13) and supernumerary ring chromosomes derived from the t(17;22). In this report, the breakpoints from translocations and rings in DP and its juvenile form, giant cell fibroblastoma (GCF), were characterised on the genomic and RNA level. These rearrangements fuse the platelet-derived growth factor B-chain (PDGFB, c-sis proto-oncogene) and the collagen type I alpha 1 (COL1A1) genes. PDGFB has transforming activity and is a potent mitogen for a number of cell types, but its role in oncogenic processes is not fully understood. COL1A1 is a major constituent of the connective tissue matrix. Neither PDGFB nor COL1A1 have so far been implicated in any tumour translocations. These gene fusions delete exon 1 of PDGFB, and release this growth factor from its normal regulation.

Chromosome Breakage↗
PubMed1997

Inherited DNA amplification of the proximal 15q region: cytogenetic and molecular studies.

In a 15 year old girl, referred for growth retardation, conventional cytogenetic analysis detected an abnormal 15q+ chromosome with extra material in the proximal region, inherited from her father and grandfather. Using various molecular cytogenetic techniques, including comparative genomic hybridisation, we showed that the extra chromatin resulted from in situ amplification of DNA sequences located between the loci D15Z1 and D15S18. On the basis of the clinical features of our patient and the late replication of the large amplified region, we searched for functional modifications in the adjacent Prader-Willi syndrome region.

Adolescent↗
PubMed1997

Experimental assessment of the detection limit of genomic amplification by comparative genomic hybridization CGH.

Artificial amplicons of known size, constructed by use of YACs featuring human 8p12 and 12q13, were analyzed by comparative genomic hybridization (CGH). A minimum of 15 Mb of overrepresented DNA sequences could be detected. The sensitivity is (1) not dependent on the chromosome site and (2) related to the size of the amplicon, decreasing with decreasing size.

Chromosome Mapping↗
PubMed1997

Collaborative study of mosaic tetrasomy 12p or Pallister-Killian syndrome (nineteen fetuses or children).

The difficulties in the diagnosis of Pallister-Killian syndrome are illustrated in this study of nineteen fetuses and children. Diagnosis based on clinical appearance alone is often difficult due to the broad spectrum of clinical anomalies not specific to this syndrome. Due to mosaicism, it is altogether necessary to examine several tissues for the presence of tetrasomy 12p, including circulating lymphocytes in which mosaicism can be as low as 1-3%, amniocytes, chorionic cells and skin fibro-blasts in which mosaicism ranges from 6-100%. When highly suspected on ultrasound examination, the diagnosis recommends prenatal cytogenetic studies because survivors are severely mentally retarded. All the cases are sporadic with only a single preliminary report of recurrence. The cytogenetic diagnosis is therefore helpful in order to reassure family members in regard to genetic counseling.

Abnormalities, Multiple↗
PubMed1996

Another case of t(17;22)(q22;q13) in an infantile dermatofibrosarcoma protuberans.

We have identified a new dermatofibrosarcoma protuberans (DP) case with a t(17;22) (q22;q13) occurring in a child. The translocation was substantiated by the presence of one or two copies of the sole der(22)t(17;22). This rearrangement added to two normal chromosomes 17 and one or two chromosomes 22, resulted in trisomy 22cen-q13 and trisomy (or tetrasomy) 17q22-25. This observation confirms the specificity of the association of DP with the t(17;22) found together with extra copies of the der(22)t(17;22). It also points out a possible prevalence of translocation rather than rings in DP of the childhood disease.

Antigens, CD34↗
PubMed1996

Homocysteine response to methionine challenge in four obligate heterozygotes for homocystinuria and relationship with cystathionine beta-synthase mutations.

Fasting and post-methionine load plasma total homocysteine concentrations were investigated in the parents of two homocystinuric patients. Three genetic mutations in the cystathionine beta-synthase gene were found. In the patient of family 1, a frequent Caucasian mutation. T833C, was found on one allele, while the mutation on the other allele has not yet been defined. In the patient of family 2, a mutation C569T, recently described by Sperandeo and colleagues, was found on one allele, while a novel mutation, G346A, was characterized on the other allele. The frequent gene mutation T833C was detected in a heterozygous mother who, surprisingly, exhibited strictly normal fasting and post-methionine load homocysteinaemia. In contrast, in the other family, we found a novel mutation (G346A) in the mother located near Lys 119, the putative binding site of phosphopyridoxal phosphate. This mother exhibited increased fasting and post-methionine load homocysteinaemia. These observations could explain the conflicting results reported for vascular pathologies in parents of homocystinuric patients and direct the search for genetic mutations in these vascular pathologies.

Adolescent↗
PubMed1996

Translocation, t(17;22)(q22;q13), in dermatofibrosarcoma protuberans: a new tumor-associated chromosome rearrangement.

A translocation, t(17;22)(q22;q13), was identified in two cases of dermatofibrosarcoma protuberans (DP). They bring to four the number of DP cases characterized by an identical t(17;22)(q22;q13), which can be considered as a new tumor-associated chromosome rearrangement. To date, this translocation has been found only in DP and its juvenile form, giant-cell fibroblastoma. This finding has two major consequences. First, it casts light on the development and significance in DP of ring chromosomes which consistently harbor sequences derived from chromosomes 17 and 22. Second, the identification of this new chromosome marker, and eventually of the underlying molecular rearrangement, should help to classify DP, a soft-tissue tumor of still uncertain cell origin. In addition, it could be used to differentiate DP from truly benign or malignant entities, in order that this tumor of intermediate malignancy could be adequately managed.

Adolescent↗
PubMed1995

Cytogenetics of malignant gliomas: I. The autosomes with reference to rearrangements.

Autosomal chromosome abnormalities are far from always detectable and, when detected, far from fully consistent in malignant gliomas. In 15 of 41 malignant gliomas, we found autosomal chromosome aberrations ranging from solitary trisomy to a wildly abnormal polyploid complement. The sequence of chromosome events appears to proceed from the normal to the near-diploid state (via structural and numerical changes) to near-tetraploidy (via polyploidization), and finally toward near-triploidy (via chromosome loss and additional rearrangements). Characteristic chromosome changes of trisomy 7 and monosomy 10 were repeatedly found, usually together in the same cell clones. In only one case was trisomy 7 an isolated change. We observed structural rearrangements of chromosomes 7 and 10 which may be of some use in mapping specific genes duplicated or deleted by the whole-chromosome changes of chromosomes 7 and 10. Nonrandom structural changes of other autosomes, including chromosomes 1, 5, and 11, fit with the model of malignant glioma as a process involving multiple genes. An unusual concentration of breakpoints in 12q13, juxtaposing it to at least five other regions, reflects the presence of genetic information in 12q13 important to the development of malignant gliomas.

Adult↗
PubMed1995

Cytogenetics of malignant gliomas. II. The sex chromosomes with reference to X isodisomy and the role of numerical X/Y changes.

Sex chromosomal monosomy with total loss of an X or Y is frequently observed in malignant gliomas. Beyond that, not much is known about the behavior of the sex chromosomes in these tumors. We noted loss of the X from 3 of 13 gliomas from women (23%) compared to loss of the Y from 16 of 28 gliomas from men (57%). There were two structural rearrangements of the Y (an inversion and a translocation with chromosome 4). Most unexpectedly, clones with sex chromosome reversal were encountered in 3 cases. These XX clones in gliomas from men are perforce the consequence of Y loss coupled with X isodisomy, a nonrandom sequence of sex chromosome changes. We examined the company kept by numerical X and Y changes in clones and found that clones with numerical sex chromosome changes had fewer autosomal abnormalities, reflecting a distinct tendency to clonal separation of sex chromosome from autosomal abnormalities. We conclude that the sex chromosome changes are not a necessary part of the neoplastic process in malignant gliomas but that they must be of biologic significance to the brain since they are highly nonrandom in frequency, type, and sequence in brain cells.

Adult↗
PubMed1995

Ring 22 chromosomes in dermatofibrosarcoma protuberans are low-level amplifiers of chromosome 17 and 22 sequences.

Ring chromosomes have been found with some regularity as solid tumors have come increasingly under cytogenetic study. The full genetic content and significance of these rings remain unclear. Dermatofibrosarcoma protuberans, a tumor of the deep dermis, consistently has supernumerary ring chromosomes, sometimes as the sole detectable cytogenetic change. Using a modified method for comparative genomic hybridization and fluorescent in situ hybridization with a panel of various probes, we found that these ring chromosomes consistently contain the chromosome 22 centromere along with interstitial sequences from chromosomes 17 and 22, specifically from regions 17q23-24 and 22q11-12. The ring chromosomes in dermatofibrosarcoma protuberans are vehicles for a particular pattern of relatively low-level genomic amplification of selected sequences.

Adult↗
PubMed1995

Sensitive detection of numerical and structural aberrations of chromosome 1 in neuroblastoma by interphase fluorescence in situ hybridization. Comparison with restriction fragment length polymorphism and conventional cytogenetic analyses.

Chromosome I abnormalities are indicators of prognosis in neuroblastoma (NB) but are not yet routinely exploited because conventional methods are technically demanding. We evaluated the pertinence of interphase cytogenetics fluorescence in situ hybridization (FISH) for the analysis of chromosome I in NB, compared with conventional methods. Deletion of Ip was detected in 8 of 9 cell lines analyzed by both FISH and restriction fragment length polymorphism (RFLP), but was evidenced in only 2 cases by conventional cytogenetics, painting analysis being required to reveal the other cases. The chromosome I number evaluated by FISH reflected the total chromosome modal number obtained by cytogenetics. Twenty-eight specimens obtained from ultrasound-guided punctures, surgical biopsies of the primary tumor and bone-marrow aspirates were studied by FISH on frozen cytocentrifuged smears; 12 had a chromosome I trisomy and 16 a disomy. Requirements for a reliable control analysis of Ip deletion by RFLP were met in only 23 cases. The retention of 2 alleles was observed in 15 cases and Ip deletion in 7, by both techniques. In one case, an interstitial deletion of Ip was evidenced only by RFLP, and one of 5 cases analyzed only by FISH had a Ip deletion. Although FISH might be improved by using additional probes, it presents major advantages for routine exploitation. Determining Ip deletion in individual cells makes it possible to analyze small and heterogeneous tumoral specimens; the technique requires only a few hours and can easily be standardized in non-specialized laboratories. The number of chromosome I homologues per cell might serve as a rapid screening for ploidy.

Biopsy↗
PubMed1995

Involvement of chromosomes 17 and 22 in dermatofibrosarcoma protuberans.

Literature on the cytogenetics of dermatofibrosarcoma protuberans (DFSP) is limited; only 10 cases with chromosome aberrations have been reported. They are karyotypically characterized by the presence of supernumerary ring(s), either as the sole cytogenetic abnormality or together with a few additional structural or numerical changes. We report the cytogenetic and fluorescence in situ hybridization (FISH) analysis of three new DFSP, one primary and two recurrent tumors. In two cases we found a supernumerary ring as the sole change, whereas the third had two copies of a marker chromosome and monosomy of chromosome 22. Sequences of chromosomes 17 and 22 were identified by FISH in the supernumerary rings and in the markers. The fluorescence pattern suggested that additional sequences were present in the two rings, but showed that the marker chromosomes were entirely painted by chromosome 17 and 22 probes. The findings indicate that juxtaposition and/or amplification of chromosome 17 and 22 sequences could be crucial in the pathogenesis of DFSP.

Adult↗
PubMed1995

Chromosomes in gliomatosis cerebri.

Gliomatosis cerebri is a rare brain tumor which histologically resembles a diffuse cerebral astrocytoma. It can simultaneously infiltrate multiple sites in the cerebrum, cerebellum, brainstem, and spinal cord. This remarkable diffuseness has led to the idea that gliomatosis cerebri does not derive from a solitary focus but must arise from a broad field of glial cells. We studied the chromosomes from gliomatosis cerebri in a 12-year-old boy by conventional cytogenetics and fluorescence in situ hybridization (FISH). Aside from normal cells, we found a majority of cells with the karyotype 44,XY,del(6)(q25),del(14)(q21), der(15;21)(q10;q10),add(18)(q22),del(19)(p12),add(20)(p13),-21. A smaller proportion of cells had 88 chromosomes with a doubling of this abnormal karyotype. These findings are consistent with a clonal neoplasm stemming from a single cell. The chromosome changes we observed, with the possible exception of the chromosome 6 deletion, did not resemble those frequently found in astrocytomas. Gliomatosis cerebri may therefore belong to a separate category of brain tumors.

Brain Neoplasms↗
PubMed1995

Characteristic chromosome abnormalities and karyotype profiles in soft tissue tumors.

Characteristic chromosome abnormalities and karyotype profiles are emerging for the soft tissue tumors. The notable findings are summarized in the Table 1. Within the broad range of solid tumors, it is certainly the soft tissue tumors in which the most spectacular success has occurred with regard to neoplasia-associated chromosome abnormalities. Cytogenetic studies of soft tissue tumors have been encouraged by the early and growing supporting interest of pathologists and clinicians concerned with soft tissue tumors. However, when one considers the variety of types and subtypes of benign and malignant soft tissue tumors, the number that has been so far characterized by a specific chromosome change is still very small. But, as we attempt to demonstrate in this report, these data should be viewed as paradigms for the importance of cytogenetic investigations in solid tumors. Cytogenetic studies of solid tumors are of more than clinical interest. Cytogenetic studies allow molecular investigations of the chromosomal breakpoints. They allow the search to proceed for genes involved in the chromosomal changes, providing a better knowledge of the malignant transformation process. In addition, the fruits of the combined efforts in cytogenetic and molecular technologies, from which has come "molecular cytogenetics," will let us recognize more conveniently, more quickly and, hopefully, less expensively the well-characterized diagnostic chromosome markers in tumor cells. Thus, we may be able to reach the goal of incorporating cytogenetics into standard diagnostic procedures for solid tumors, as has been achieved with hematological malignancies. Molecular cytogenetics including fluorescent in situ hybridization (FISH) technology promises to bring soft tissue tumor cytogenetics into regular diagnostic armamentaria and concurrently speed research into the basis of soft tissue tumors.

Chromosome Aberrations↗
PubMed1995

Oncogenic conversion of a novel orphan nuclear receptor by chromosome translocation.

A recurrent t(9;22) (q22;q12) chromosome translocation has been described in extraskeletal myxoid chondrosarcoma (EMC). Fluorescent in situ hybridization experiments performed on one EMC tumour indicated that the chromosome 22 breakpoint occurred in the EWS gene. Northern blot analysis revealed an aberrant EWS transcript which is cloned by a modified RT-PCR procedure. This transcript consists of an in-frame fusion of the 5' end of EWS to a previously unidentified gene, which was named TEC. This fusion transcript was detected in six of eight EMC studied, and three different junction types between the two genes were found. In all junction types, the putative translation product contained the amino-terminal transactivation domain of EWS linked to the entire TEC protein. Homology analysis showed that the predicted TEC protein contains a DNA-binding domain characteristic of nuclear receptors. The highest identity scores were observed with the NURR1 family of orphan nuclear receptors. These receptors are involved in the control of cell proliferation and differentiation by modulating the response to growth factors and retinoic acid. This work provides, after the PML/RAR alpha gene fusion, the second example of the oncogenic conversion of a nuclear receptor and the first example involving the orphan subfamily. Analysis of the disturbance induced by the EWS/TEc protein in the nuclear receptor network and their target genes may lead to new approaches for EMC treatment.

Amino Acid Sequence↗