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F E Cotter

Publications and source records attributed to F E Cotter.

At least 55 records · Page 3Linked to original sources
PubMed1994

Molecular cloning of a novel 11q23 breakpoint associated with non-Hodgkin's lymphoma.

Chromosomal analysis of a non-Hodgkin's lymphoma revealed a t(11;14)(q23;q32) translocation amongst other abnormalities. To investigate the molecular basis of this translocation, a cosmid library was constructed from the tumour DNA and the rearranged IGH locus was isolated in a single cosmid. Fluorescence in situ hybridization confirmed that the cloned region contained sequences from chromosome 11q23 fused to chromosome 14q32. Sequence analysis identified the breakpoint as a fusion between a region from the switch segment of the C gamma 4 gene of the IGH locus and an unknown sequence on chromosome 11. The chromosome 11 sequence maps proximal to the CD3 gene cluster and is therefore distinct from both the HTRX1 gene (rearranged in acute leukaemias) and the RCK gene (rearranged in a cell line derived from a histiocytic B-cell lymphoma). This newly identified region contains a cluster of rare cutting restriction enzyme sites located within 200 bases of the breakpoint, suggestive of a CpG island. Although this t(11;14)(q23;q32) translocation and that in the RC-K8 cell line affect different regions on chromosome 11, the breakpoints on chromosome 14 were found to have occurred at equivalent positions of S gamma 2 and S gamma 4 segments.

Adult↗
PubMed1993

Posttransplant cutaneous lymphoma.

BACKGROUND: Posttransplant lymphoma is closely associated with Epstein-Barr virus (EBV) infection and appears to have a predilection for extranodal sites. We describe four cases of primary cutaneous posttransplant lymphoma. OBJECTIVE: Our aim was to determine cell lineage and any possible association with EBV in each case of cutaneous lymphoma. METHODS: Tumor tissue was examined by light microscopy, immunohistochemistry, nonisotopic in situ hybridization and polymerase chain reaction. RESULTS: The data were consistent with a diagnosis of EBV-associated cutaneous B-cell lymphoma in three cases and cutaneous T-cell lymphoma not associated with EBV in one case. No patient with B-cell lymphoma had extracutaneous involvement during a mean follow-up of 3.9 years. The patient with cutaneous T-cell lymphoma died of cerebral involvement 9 months after initial presentation. CONCLUSION: These data suggest a possible role for EBV infection in the origin of cutaneous B-cell lymphoma in immunosuppressed patients.

Aged↗
PubMed1993

Molecular pathology of lymphomas.

Chromosomal translocations appear to be the initiating step in the development of malignancy in both B cell and T cell lymphomas. These results in the juxtapositioning of proto-oncogenes and transcriptional factors to the IG or TCR genes and lead to the deregulation of their expression. A survival advantage is provided to the lymphoid cells and contributes to neoplasm by permitting a clone to persist until other oncogenes such as c-myc are activated. This suggests a multistep progression to tumorigenesis. The occurrence of these translocations is assisted by obligatory DNA breaks and rearrangements of IG and TCR that have to occur for B and T cells to mature and function. The molecular alterations specific to lymphomas provide a potential specific target for therapy, including molecular manipulations. Animal modelling of lymphoma will provide the greatest possibilities for investigating the pathogenesis of lymphoma and future treatment modalities.

Gene Expression Regulation, Neoplastic↗
PubMed1992

Fluorescent in situ identification of human marker chromosomes using flow sorting and Alu element-mediated PCR.

A novel approach to the identification of human chromosomes has been developed. Chromosomal in situ hybridization (or "chromosome painting") has been performed using Alu element-mediated PCR products from small quantities (250-500) of flow-sorted normal and abnormal chromosomes. Chromosome paints for various normal chromosomes, including 5, 6, 7, 14, 18, 19, 21, and 22, were generated and shown to be effective in the identification of the appropriate chromosomes. In addition, certain abnormal chromosomes, including a mental retardation-associated deletion chromosome 11 (q22-q23), the products of the constitutional translocation t(11;22), and the CML-associated t(9;22), were used to generate region-specific paints. In each case, the appropriate regions of the chromosomes were highlighted and this strategy is, therefore, well suited to the identification of previously unidentified marker chromosomes. A further direct consequence of this work is that chromosome paints specific for the common aberrant chromosomes, such as the Philadelphia chromosome, can be generated and made widely available. These may find particular use in the analysis of complex or masked chromosomal translocations.

Base Sequence↗
PubMed1992

Isolation of chromosome-specific DNA sequences from an Alu polymerase chain reaction library to define the breakpoint in a patient with a constitutional translocation t(1;13) (q22;q12) and ganglioneuroblastoma.

We describe the cytogenetic and molecular characterization of a t(1;13)(q22;q12) constitutional rearrangement occurring in a patient with a relatively benign form of neuroblastoma, called ganglioneuroblastoma. Somatic cell hybrids were generated between mouse 3T3 cells and a lymphoblastoid cell line from this patient, D.G. One isolated subclone, DGF27C11, contained the derivative chromosome, 1pter-q22::13q12-qter, but no other material from either chromosome 1 or 13. Using available DNA probes the 13 breakpoint was assigned proximal to all reported markers. In order to generate flanking markers to define this translocation further, an Alu polymerase chain reaction library was constructed from a somatic cell hybrid containing only the proximal, 13pter-13q14, region of chromosome 13. Seven unique sequences have been isolated from the library, three of which lie below and four of which lie above the 13q12 breakpoint. More precise mapping of the distal markers was achieved using a panel of somatic cell hybrids with overlapping deletions of chromosome 13. The paucity of probes in the 1q22 region has made a precise assignment of this breakpoint difficult, however it has been shown to lie distal to c-SKI and proximal to APOA2. This refined characterization of the breakpoint is a prerequisite for its cloning, which may yield genes important in the pathogenesis of ganglioneuroblastoma.

Base Sequence↗
PubMed1991

Gene mapping by microdissection and enzymatic amplification: heterogeneity in leukaemia associated breakpoints on chromosome 11.

A new strategy for mapping chromosome translocation breakpoints in relation to known genes has been developed. This approach is based on the amplification by the polymerase chain reaction (PCR) of specific target sequences from small numbers of microdissected chromosome fragments. This method has been applied to leukaemia-associated translocations affecting the q23 region of chromosome 11. In two independent leukaemias, the t(6;11) translocation was distinguished from the t(9;11) and t(4;11) translocations by demonstrating that the former breakpoint on chromosome 11 lay proximal to the CD3D gene while the latter breakpoints lay distal to CD3D. All three translocation breakpoints were found to lie proximal to ETSI and THYI. The data suggest that although these leukaemia-associated breakpoints on chromosome 11 are cytogenetically identical they may involve disruption of different genes. This approach offers a rapid alternative to mapping by hybridisation of probes either in situ to chromosomes or to somatic cell hybrids containing the appropriate derivative chromosomes.

Base Sequence↗
PubMed1991

CD3G is within 200 kb of the leukemic t(4;11) translocation breakpoint.

The t(4;11)(q21;q23) has been associated with acute lymphocytic leukemia (ALL) especially in infants. The t(4;11) breakpoint on chromosome 11 is cytogenetically indistinguishable from breakpoints for other leukemia-associated translocations affecting 11q23. The molecular basis of the t(4;11) is unknown although a number of genes have been mapped to 11q23. The CD3D, G, and E genes have been positioned proximal to the 11q23 breakpoint of the 4;11 translocation while the THY1 and ETS1 genes have been mapped distal to this breakpoint. We report evidence that CD3G is within 200 kb of the 4;11 breakpoint as observed by pulsed field gel analysis. A rearrangement of the CD3G gene has been observed in a cell line derived from a patient with the t(4;11) translocation and in a hybrid cell line containing the derivative 11q chromosome derived from this cell line, using the restriction enzymes SacII and ClaI. Similar rearrangements using SacII were observed in 2 further patients with ALL and the t(4;11) translocation. No rearrangements in the same DNA were observed using ETS1, THY1, and D11S29 and a range of rare cutter restriction enzymes. CD3G thus provides a tool for the cloning and analysis of the 4;11 translocation, and poses a question of its possible involvement at long range with this translocation.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Direct sequence analysis of 14q+ and 18q- chromosome junctions at the MBR and MCR revealing clustering within the MBR in follicular lymphoma.

The t(14;18) translocation is a highly consistent feature of follicular lymphoma although the underlying mechanism generating this fusion remains uncertain. The breakpoints on chromosome 18 are at one of two sites, designated mbr and mcr, in the bcl-2 gene. A polymerase chain reaction strategy has been developed for amplification and direct sequencing of the resultant 14q+ and 18q- reciprocal junctions. Sequence analysis of the amplified 14q+ junction established that 21 tumours contained a bcl-2 (mbr) sequence to an immunoglobulin JH region, the majority being J5 or J6. A nonrandom pattern of breakpoints within the mbr region was found. Clustering of the breakpoint occurred with over 60% of the translocations clustering within 10 bases. There was a second cluster within the mbr 50 bases 3' of the first cluster. One of these junctions had an unusual configuration with the bcl-2 and JH sequences separated by a recognisable DH region. This suggests that at least some of the junctional sequences, previously thought of as N insertions, may be fragments of unrecognised DH regions. In one of these tumours it was possible to sequence the reciprocal 18q- junction, showing it to consist of a DH/bcl-2 (mbr) fusion. Analysis of both reciprocal junctions for a translocation in the mcr region of bcl-2, showed that this 18q- junction also consisted of DH fused to a bcl-2 sequence. In contrast to previous analyses, which demonstrated either loss or duplication of bcl-2 sequences at the breakpoints, the bcl-2 sequence was conserved during the mbr and mcr translocations in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1991

The generation of DNA probes to chromosome 11q23 by Alu PCR on small numbers of flow-sorted 22q- derivative chromosomes.

A strategy for the isolation of DNA probes from small numbers of flow-sorted human chromosomes has been developed. A lymphoblastoid cell line carrying the 22q- derivative chromosome product of the constitutional t(11;22) translocation was used as the source of chromosomes. Synthetic oligonucleotide primers, based on the consensus Alu sequence, were used to amplify inter-Alu sequence from 500 flow-sorted 22q- derivative chromosomes. The amplified sequences were cloned into a plasmid vector by blunt-end ligation, yielding clones with inserts in the range of 400 to 1000 bp. Approximately 70% of these clones hybridized to human DNA as single-copy probes. To identify clones derived from chromosome 11, the library was screened with a heterogeneous probe prepared by Alu-PCR amplification from the DNA of a somatic cell hybrid containing one homology of chromosome 11. All the positive clones found were mapped to within the q23-q25 region of chromosome 11 known to be translocated onto the 22q- derivative chromosome. Further mapping studies showed that most of these probes (7/8) lay between the breakpoints for the t(4;11) translocation of acute lymphocytic leukemia and the t(11;22) of Ewing sarcoma. Thus, the use of Alu-PCR on the small derivative chromosome 22q- has provided a greatly enriched source of probes to region 11q23, a part of the genome that is currently of great interest. This approach will be particularly appropriate to small numbers of chromosomes when high specificity rather than total representation is required.

Animals↗
PubMed1991

Altered gene expression and oncogenesis of B-cell neoplasia.

B-cell malignancies reveal a number of consistent translocations involving the C-MYC, BCL and IG genes. In common, these rearrangements usually lead to an inability of the involved B-cells to respond to normal regulatory controls for expression of the genes. This usually lead to over-production of the protein products of the genes at inappropriate times of the cell growth cycle and appears to allow a survival advantage to the B-cell. The result of these changes almost certainly plays a prominent role in the development of B-cell neoplasia. Classification of these lymphoma's at a molecular level may be of benefit to determine the prognosis and treatment in addition to providing a useful marker of disease. Determining the molecular basis of these B-cell lymphomas may help our understanding of their pathogenesis. This in turn could lead to more rational treatment aimed at altering the abnormal molecular changes and returning the neoplastic cells to normal cell development.

Chromosomes, Human, Pair 11↗
PubMed1991

A cutaneous B-cell lymphoma of novel immunophenotype.

A case of low-grade B-cell malignant lymphoma with a prolonged restriction to the skin is described. A rearrangement of the immunoglobulin heavy-chain gene was detected using molecular techniques. The histology showed many similarities to primary mucosal lymphomas and this may represent a skin counterpart of these tumours.

Adult↗
PubMed1991

The significance of circulating cells carrying t(14;18) in long remission from follicular lymphoma.

Peripheral blood mononuclear cell fractions from 15 patients in continuous clinical remission from follicular lymphoma for longer than 10 years were examined for cells carrying the t(14;18) translocation using the polymerase chain reaction (PCR). The assay used was able to detect one positive cell in approximately 5 x 10(5) cells (a single 14q+ molecule in 2.5 micrograms DNA). Cells positive for t(14;18) were found in six of eight patients initially presenting with stage III or IV disease, compared with zero of seven of those with stage I or II disease (P less than .05). In two cases 14q+ junction regions were also successfully amplified from formalin-fixed biopsy material obtained at presentation 12 and 17 years previously. In both, sequence analysis demonstrated that the cells circulating in remission belonged to the original clone. These results indicate that cells bearing t(14;18) frequently persist in the peripheral blood in long remission of advanced follicular lymphoma and question the value of their presence as a predictor of relapse.

Adult↗
PubMed1990

Rapid isolation of human chromosome-specific DNA probes from a somatic cell hybrid.

A strategy for the rapid isolation from rodent hybrids of human chromosome-specific probes by enzymatic amplification is described. Synthetic oligonucleotide primers based on the consensus Alu sequence were used to amplify inter-Alu sequence from total human genomic DNA and from a somatic cell hybrid, PNTS-1, containing one homolog of chromosome 5 as its only human complement. Direct sequence analysis of the products from human genomic DNA confirmed their inter-Alu structure and provided a novel means for the examination of the 5' end of the Alu consensus. The amplified sequences from the somatic cell hybrid DNA were cloned into a plasmid vector by blunt-end ligation, yielding clones with inserts in the range 300 to 1000 bp. More than 80% of these clones carried inserts that behaved essentially as single-copy human sequences. Hybridization of a selection of these clones to human DNA, hamster DNA, and the original hybrid DNA confirmed that they were derived from chromosome 5. Direct sequence analysis of the vector/insert boundaries in two clones confirmed that inter-Alu sequences had been cloned. This approach has significant advantages over other methods of isolating chromosome-specific probes from hybrid cells, enabling direct separation and cloning of human DNA probes that can be readily used for mapping studies.

Animals↗