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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chromosome analysis was performed on 1 patient with diffuse lymphoma of mixed type by histologic diagnosis and on 7 patients with the acute type of adult T-cell leukemia (ATL). Specific abnormalities in chromosome 14 at break band q11 with the assigned locus of the alpha-chain gene of the T-cell antigen receptor were identified in 6 of 8 patients. Inv(14) (q11q32) was found in 2 patients and translocation of chromosome 14 at break band q11 was observed in 4. Donor chromosomes involved in translocation of the 14q11 varied, i.e., chromosomes 3, 7 or X, with the exception of one patient whose donor chromosome origin could not be determined. The breakpoint in chromosome 3 was in band p25, a region reported to include the locus of the c-raf-I oncogene. In chromosome 7, it was in band p11, a region reported to include the locus of the c-erb-B oncogene, and in the sex chromosome X, it was in band q11. One patient also had a chromosome 14 aberration at break band q32. Of the 2 remaining patients, one had lost chromosome 14 and the other had an isochromosome 14q. Our observation and other reported findings suggest that the rearrangement of chromosome 14 at break band q11 is specific for lymphoma-type or acute-type ATL patients, and aberrations of proto-oncogene expression or the coding sequence by recombination involving a T-cell antigen receptor gene due to chromosome inversion or chromosome translocation may play an important role in T-cell neoplasia including ATL.
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PMID:Specific abnormalities of chromosome 14 in patients with acute type of adult T-cell leukemia/lymphoma. 288 76

Polymorphic variation of the c-raf-1 proto-oncogene is reported here for the first time. In a study of 21 individuals, including 17 with non-Hodgkin's lymphoma and three healthy controls, we have identified three c-raf-1 alleles. One variant allele was observed in both a mother and her son, both of whom had lymphoma, but in no other case. The other variant allele was observed in two patients with lymphoma and in a healthy control.
Leukemia 1987 Jan
PMID:Allelic variation of the c-raf-1 oncogene in non-Hodgkin's lymphoma. 288 52

We have recently described a t(8;14)(q24;q11) translocation which appeared secondarily in a non-established acute T-cell leukaemia and involved the 3' region of c-myc proto-oncogene and the alpha chain of the T-cell receptor gene (TcR-alpha). In order to elucidate the mechanism of the translocation, we have isolated breakpoint regions from normal and recombinant chromosomes. Our results show that the translocation occurred at the 3' end of a V alpha segment in the proximity of recombination signal sequences (5'-heptamer-23bp spacer-nonamer-3'). Interestingly, an inverted heptamer internal to the V alpha segment was found at two nucleotides 5' of the break. Nucleotide sequence analysis also revealed the presence of homologous signal sequences on chromosome 8, suggesting that the recombination enzymatic system played an important role in the generation of the translocation. This hypothesis is supported by the addition of N nucleotides and the loss of only three nucleotides during the rejoining process. These data established the involvement of a V alpha segment and its recombination signals in the mechanisms of t(8;14) translocations in T-cell leukaemias.
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PMID:Molecular mechanisms of a t(8;14)(q24;q11) translocation juxtaposing c-myc and TcR-alpha genes in a T-cell leukaemia: involvement of a V alpha internal heptamer. 296 21

Alterations in genes that function in normal growth and development have been linked to malignant cell transformation. The mononuclear phagocyte colony-stimulating factor (CSF-1 or M-CSF) is a polypeptide growth factor synthesized by mesenchymal cells, which stimulates the survival, proliferation, and differentiation of haematopoietic cells of the monocyte-macrophage series. Multiple forms of soluble CSF-1 are produced by proteolytic cleavage of membrane-bound precursors, some of which are stably expressed at the cell surface. The c-fms proto-oncogene encodes the CSF-1 receptor, which is composed of an extracellular ligand-binding domain linked by a single membrane-spanning segment to a cytoplasmic tyrosine-specific protein kinase domain. Whereas the tyrosine kinase activity of the normal receptor is stimulated by CSF-1, mutations in the c-fms gene can constitutively activate the kinase to provide growth-stimulatory signals in the absence of the ligand. Oncogenic activation of the c-fms gene product appears to involve removal of a negative regulatory tyrosine residue near the carboxyl terminus of the receptor and one or more additional mutations that may simulate a conformational change induced by CSF-1 binding. Expression of the human c-fms gene in mouse NIH-3T3 cells confers a CSF-1 stimulated growth phenotype, indicating that receptor transduction is sufficient for fibroblasts to respond to a haematopoietic growth factor. In contrast, the v-fms oncogene induces factor-independent growth and tumorigenicity in factor-dependent myeloid cell lines, and contributes to the development of proliferative disorders of multiple haematopoietic lineages when introduced into murine bone marrow progenitors. Aberrant expression of an endogenous c-fms gene secondary to proviral insertion and transcriptional activation has also been implicated in virus-induced myeloblastic leukaemia in mice. The c-fms and CSF-1 genes have been mapped on the long arm of human chromosome 5, a region that frequently undergoes interstitial deletions in certain haematopoietic disorders including acute myelogenous leukaemia. The study of CSF-1 and its receptor should provide information concerning the role of tyrosine kinases in regulating the normal growth and differentiation of haematopoietic cells and in contributing to their malignant transformation.
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PMID:The colony-stimulating factor 1 (CSF-1) receptor (c-fms proto-oncogene product) and its ligand. 297 16

Analysis of total feline DNA by genomic blot hybridization, using the viral oncogene of Abelson murine leukemia virus as a specific probe, has led to the identification of multiple v-abl homologous genetic sequences in the cat genome. Upon restriction endonuclease BamHI digestion, the combined size of the v-abl homologous DNA fragments was about 31 kbp. To characterize these sequences further, four independent v-abl homologous cosmid clones with overlapping cellular inserts have been isolated from a gene library of cat lung genomic DNA. These inserts represent a contiguous region of cellular DNA sequences of 56 kbp in length. Within this region of the feline genome, the v-abl homologous sequences are discontinuously dispersed over a region of about 34 kbp. They represent the complete feline v-abl cellular homolog and are colinear with the viral v-abl oncogene. Nine regions of highly repetitive DNA sequences have been mapped in close proximity to v-abl homologous sequences. These results establish the presence of only a single c-abl proto-oncogene in the cat genome and present its genetic organization.
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PMID:Characterization of the feline c-abl proto-oncogene. 298 4

The Philadelphia (Ph') chromosome, an abnormal chromosome 22 (ref. 1), is one of the best-known examples of a specific human chromosomal abnormality strongly associated with one form of human leukaemia, chronic myelocytic leukaemia (CML). The finding that a small region of chromosome 9 which includes the c-abl oncogene is translocated to chromosome 22 prompted studies to elucidate the molecular mechanisms involved in this disease. We have demonstrated previously that the chromosome 9 of one patient with CML contains a breakpoint 14 kilobases (kb) 5' of the most 5' v-abl-homologous exon. These data suggest a role for c-abl in CML, a theory supported by the presence of an abnormally sized abl messenger RNA and protein in the CML cell line K562. The region involved in the translocation on chromosome 22 has also been identified: all Ph'-positive patients examined to date have a breakpoint within a 5.8-kb region, for which we have proposed the name 'breakpoint cluster region' (bcr). To determine whether bcr contains protein-encoding regions, probes from bcr were tested for their ability to hybridize to complementary DNA sequences. A 0.6-kb HindIII/BamHI bcr restriction enzyme fragment proved suitable for isolating several cDNA clones from a human fibroblast cDNA library. Using bcr cDNA sequences, we obtained data strongly suggesting the presence of a chimaeric bcr/abl mRNA in the leukaemic cells of Ph'-positive CML patients. The recent isolation of cDNA clones containing bcr and abl sequences confirms this finding. Because the bcr part of the chimaeric mRNA could be required to induce the transforming activity of the human c-abl oncogene, we have now initiated studies to characterize the normal 'bcr gene' and to determine the effect of a translocation within its coding domain. We demonstrate that as a result of the Ph' translocation, a variable number of bcr exons are included in the chimaeric bcr/abl mRNA. The bcr gene sequences in this mRNA could be responsible for the transition of the abl cellular proto-oncogene into an oncogene.
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PMID:Structural organization of the bcr gene and its role in the Ph' translocation. 298 3

The feline c-fes proto-oncogene, different parts of which were captured in feline leukemia virus (FeLV) to generate the transforming genes (v-fes) of the Gardner-Arnstein (GA) strain of feline sarcoma virus (FeSV) and the Snyder-Theilen strain (ST) of FeSV, was cloned and its genetic organization determined. Southern blot analysis revealed that the c-fes genetic sequences were distributed discontinuously and colinearly with the v-fes transforming gene over a DNA region of around 12.0 kb. Using cloned c-fes sequences, complementation of GA-FeSV transforming activity was studied. Upon replacement of the 3' half of v-fesGA with homologous feline c-fes sequences and transfection of the chimeric gene, morphological transformation was observed. Immunoprecipitation analysis of these transformed cells revealed expression of high Mr fusion proteins. Phosphorylation of these proteins was observed in an in vitro protein kinase assay, and tyrosine residues appeared to be involved as acceptor amino acid.
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PMID:Molecular cloning of the feline c-fes proto-oncogene and construction of a chimeric transforming gene. 299 4

The presence of a rearrangement of the proto-oncogene c-myc was investigated in the DNA of fresh cells isolated from the blood of two patients with Burkitt's leukemia (L3), and from the node biopsy of a patient with Burkitt's lymphoma. Both samples from the L3 leukemia patients had the characteristic t(8;14) translocation, while the lymphoma specimen presented no abnormality of chromosome 8. Only one of the leukemic DNA's presented a rearranged c-myc pattern, with the breakpoint region located between the first and the second exon. The c-myc pattern of the two other patients appeared normal. The finding of a rearranged c-myc oncogene in fresh cells from a Burkitt's leukemia is direct evidence for the implication of c-myc in the disease whereas most of the rearrangements previously described have been found in cell lines established in culture.
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PMID:[Rearrangement of the proto-oncogene c-myc in fresh cells from Burkitt's leukemia (L3)]. 299 97

Altered structure and regulation of the c-myc proto-oncogene have been associated with a variety of human tumours and derivative cell lines, including Burkitt's lymphoma, promyelocytic leukaemia and small cell lung cancer (SCLC). The N-myc gene, first detected by its homology to the second exon of the c-myc gene, is amplified and/or expressed in tumours or cell lines derived from neuroblastoma, retinoblastoma and SCLC. Here we describe a third myc-related gene (L-myc) cloned from SCLC DNA with homology to a small region of both the c-myc and N-myc genes. Human genomic DNA shows an EcoRI restriction fragment length polymorphism (RFLP) of L-myc defined by two alleles (10.0- and 6.6-kilobase (kb) EcoRI fragments), neither associated disproportionately with SCLC. Mouse and hamster DNAs exhibit a 12-kb EcoRI L-myc homologue, which indicates conservation of the gene in mammals. Gene mapping studies assign L-myc to human chromosome region 1p32, a location distinct from that of either c-myc or N-myc but associated with cytogenetic abnormalities in certain human tumours. This L-myc sequence is amplified 10-20-fold in four SCLC cell line DNAs and in one SCLC tumour specimen taken directly from a patient. Either the 10.0- or 6.6-kb allele can be amplified and in heterozygotes only one of the two alleles was amplified in any SCLC genome. SCLC cell lines with amplified L-myc sequences express L-myc-derived transcripts not seen in SCLC with amplified c-myc or N-myc genes. In addition, some SCLCs without amplification also express L-myc-related transcripts. Together, these findings suggest an enlarging role for myc-related genes in human lung cancer and provide evidence for the concept of a myc family of proto-oncogenes.
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PMID:L-myc, a new myc-related gene amplified and expressed in human small cell lung cancer. 299 22

The c-mos proto-oncogene is the cellular counterpart of the viral oncogene v-mos isolated from Moloney murine sarcoma virus. The c-mos gene locus has previously been assigned to human chromosome 8. By both in situ hybridization and molecular hydridization to sorted chromosome DNA (using a c-mos probe) we have localized the c-mos gene to band 8q11. This regional localization is at variance with the one previously reported at 8q22 and may explain why no rearrangement of c-mos has been found in acute leukaemia with the chromosomal translocation t(8;21)(q22;q22).
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PMID:Human proto-oncogene c-mos maps to 8q11. 300 Jul 66


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