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

Immunoglobulin and T cell receptor gene rearrangement and expression were investigated within B cell acute lymphoblastic leukemias (ALLs) that are thought to be representative of the early stages of normal human B cell development. Although the immunoglobulin heavy chain locus is rearranged in leukemic cells from all of these patients, only cells from pre-B ALL patients express mu chain protein. We have shown, however, that immunoglobulin heavy chain transcripts are expressed at levels similar to those found in normal B cells in all of these leukemic cell types and, in addition, some of the leukemias with a more mature phenotype also express immunoglobulin light chain mRNA. In contrast, leukemic cells which had rearranged T cell receptor gamma chain genes were not found to express gamma chain transcripts, indicating that the transcription of immunoglobulin and T cell receptor genes in these cells may be regulated in a lineage-specific manner.
Leukemia 1989 Nov
PMID:Immunoglobulin and T cell receptor gene rearrangement and expression in B cell acute lymphoblastic leukemia. 281 80

Rearrangements of T cell receptor beta and gamma chain (T beta and T gamma) genes were analyzed by Southern blot method in samples from 30 patients with adult T cell leukemia (ATL) and 17 patients with non-ATL T cell neoplasms. The DNA probes used were the constant and joining region of T beta gene and the joining region of T gamma gene. Rearranged bands of T beta gene on one or both allelic chromosomes were detected in all neoplastic T cells, even those of smoldering ATL, in which only a small percentage of peripheral blood T cells were detected as leukemic. T gamma gene was rearranged in the cells of all but one patient, the exception being one ATL patient. In order to test whether any given variable region (V) of T beta gene was expressed in ATL cells, two functionally rearranged V beta sequences of ATL were compared with a V beta sequence from T cells acute lymphoblastic leukemia cells. No significant homologies were noted among the three deduced gene product amino acid sequences, confirming that T beta molecules of ATL cells contained no specific structures in common. The observed heterogeneity of T beta and T gamma gene rearrangements in ATL cells further supported these findings.
Leukemia 1988 Feb
PMID:Gene rearrangements of T cell receptor beta and gamma chains in HTLV-I infected primary neoplastic T cells. 289 62

cDNA clones, whose fusion proteins were recognised by an anti-(T3 gamma chain) serum, were isolated from a lambda gt11 expression library prepared from the human T leukaemia cell line J6. The clones encoded a unique sequence related to that of the T3 delta chain, and hybridised to two mRNA transcripts of 0.8 and 3.5 kb in size, whose expression was restricted to T lymphocytes. The 182 amino acid sequence deduced from the cDNA revealed a typical signal peptide, a predominantly hydrophilic 89 amino residue domain with two N-glycosylation sites, a hydrophobic domain with a centrally located glutamic acid residue and a 44-residue domain with at least one potential serine phosphorylation site for protein kinase C. Given this arrangement the T3 gamma polypeptide most probably has a transmembrane orientation with the N-terminal domain exposed on the cell surface. The amino acid and nucleotide sequences showed marked homology with those of the T3 delta chain, suggesting that the respective genes arose by duplication about 200 million years ago. The intracellular and membrane-proximal half of the extracellular domains were especially well conserved.
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PMID:Primary structure of the T3 gamma subunit of the T3/T cell antigen receptor complex deduced from cDNA sequences: evolution of the T3 gamma and delta subunits. 294 45

Neoplastic B cells from two patients with hyperleucocytic hairy cell leukaemia (HCL) and 19 patients with chronic lymphocytic leukaemia of B cell Type (B-CLL) were investigated to examine the mitogenic responses to the F(ab')2 fraction of anti-human immunoglobulins (anti-Igs) and Staphylococcus aureus Cowan I (STA). Neoplastic cells from both HCL patients lacked surface Tac antigen. Mononuclear cells from the two HCL patients strongly responded to both anti-Igs and STA as measured by 3H-thymidine incorporation in vitro. Although the mononuclear cells from two patients with B-CLL showed high response to STA, cells from none of the patients with B-CLL responded to anti-Igs. Mononuclear cells as well as T-cell-depleted fractions from the two HCL patients showed a strong proliferative response by anti-gamma chain antibody (anti-gamma) and the mononuclear cells from one of the patients were also induced to proliferate by anti-delta, whereas those from normal subjects responded only to a high concentration of anti-mu. Based on the difference in reactivity to anti-Ig, it is suggested that the HCL cells in this study originate from a subset equivalent to 'memory' B cells, whereas the B-CLL cells originate from a subset equivalent to 'virgin' B cells.
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PMID:Mitogenic response of neoplastic B cells: comparison of reactivity to Staphylococcus aureus Cowan I and anti-immunoglobulin antibodies. 301 56

For the investigation of whether Abelson murine leukemia virus (A-MuLV) is able to transform in vivo lymphocytes other than those of the B-cell lineage, newborn BALB/c and C57BL/6 mice were given an injection of A-MuLV directly into the thymus. Thymic lymphomas appeared with a short latent period of 4-5 weeks in BALB/c mice and 8 weeks in C57BL/6 mice. Cell lines derived from some thymic lymphomas presented a very immature phenotype and did not express cellular markers of either T-cells (Thy 1.2, Lyt 1.2, and Lyt 2.2) or B-cells (cytoplasmic IgM) even after treatment with several differentiation inducers. Molecular analysis showed that T-cell receptor (TCR) beta chain genes were never rearranged; in one case only, rearrangement of TCR gamma chain genes could be demonstrated, confirming the immaturity of the presumptive T-cell lines studied. Furthermore, the cell lines consistently carried diversity (D)-joining (J) but not variable (V)-D-J rearrangements of the immunoglobulin heavy chain genes. On the whole, these findings suggest that following intrathymic A-MuLV injection neoplastic transformation does involve lymphocytes possibly of T-cell lineage, at a very early stage of differentiation.
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PMID:Abelson murine leukemia virus-induced thymic lymphomas: transformation of a primitive lymphoid precursor. 311 Apr 76

Immunoglobulin (Ig) and T cell receptor (TcR) gene rearrangements were analyzed in 101 cases of lymphoid malignancies in association with a surface phenotype study. In leukemias/lymphomas with mature phenotype, there is a good correlation between phenotypes and genotypes. However, in leukemias/lymphomas with immature phenotype, we found many discordances between phenotypes and genotypes, suggesting the stochastic nature of hematopoietic cell differentiation at the early stage. As for TcR beta and gamma chains, the rearrangement of gamma chain gene is considered to occur slightly prior to that of beta chain gene. However, we observed a mature T cell malignancy, adult T-cell leukemia, with rearranged beta chain gene and germ line gamma chain gene, showing the possible existence of another pathway of T cell differentiation.
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PMID:Immunogenotypes of lymphoid malignancies; the rearrangement of T cell receptor beta chain gene can occur before the gamma chain gene rearrangement. 313 37

Rearrangement of the beta and gamma chain genes of the TCR gene complex and of the Ig heavy chain genes were examined in three cases of childhood acute mixed lineage leukaemia. Blast cells, classified morphologically as acute lymphoblastic leukaemia (ALL) in one child and acute non-lymphocytic leukaemia (ANLL) in the other two, all co-expressed markers associated with both T (CD7, TdT) and myeloid (CD33) cells. Cytogenetic analysis detected abnormalities associated with myeloid leukaemia. Immunoglobulin heavy chain genes were not rearranged in two patients but a novel rearrangement was seen in the third. No rearrangement of the beta or gamma chains of the T-cell receptor complex were seen. Acute mixed lineage leukaemia may thus arise from a pluripotent precursor cell capable of both lymphoid and myeloid differentiation.
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PMID:Rearrangement of T-cell receptor and immunoglobulin heavy chain genes in childhood acute mixed lineage leukaemia. 314 5

To evaluate the role of the human T-cell-specific tyrosine kinase lck (YT16), we measured the levels of lck expression in thymocytes, peripheral T-cells, and leukemia T-cell lines which are arrested at different stages of thymic differentiation. The results indicate that higher levels of the lck message can be found in total thymocytes and T-cells arrested at Stage III (thymocytes that have rearranged their alpha, beta, and gamma chain T-cell receptor genes). A 20-fold lower level of these transcripts, however, can be found in cells derived from Stage I cells (thymocytes with germline alpha, beta, and gamma genes), 4 times less messages in Stage II cells (thymocytes with rearranged gamma and beta chain genes, but with germline alpha chain genes), and a 4-fold lower amount of RNA in Stage IV cells (mature lymphocytes). Culture of these cells with a variety of inducing reagents indicated that leukemia cell lines of only Stages I and II can be induced to increase their levels of YT16 expression by the addition of tetradecanoyl phorbol-13-acetate. These results suggest that there may be a developmental regulation of these tyrosine kinase messages during T-cell ontogeny. The high level of these transcripts in more mature T-cell leukemia lines suggests that they may primarily play a role in the proliferative controls of these cells.
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PMID:Expression of the human T-cell-specific tyrosine kinase YT16 (lck) message in leukemic T-cell lines. 325 10

The structure of immunoglobulin heavy chain (IgH) and T cell antigen receptor (TCR) beta and gamma chain genes was studied in 38 cases of adult and two cases of childhood acute lymphoblastic leukemia (ALL). Seven cases of T-ALL all showed clonally rearranged TCR beta and gamma genes; only one of these also contained rearranged IgH genes. All precursor B cell ALLs and one case of unusual B cell ALL/lymphoma had clonally rearranged IgH genes, but a high proportion (22 of 32, 69%) of precursor B cell ALLs also had rearrangement of TCR beta and/or gamma genes. TCR beta gene rearrangement was less common in more mature precursor B cell ALL, expressing cytoplasmic IgM (pre-B-ALL) (0 of 5) than in other precursor B cell ALL cases (15 of 27). In the precursor B cell ALLs overall, 10 (32%) had rearrangement of both beta and gamma genes, while 7 (22%) had rearrangement of TCR gamma genes only. A further 5 (16%), all expressing one or more unusual immunophenotype markers, had TCR beta gene rearrangement without detectable gamma gene rearrangement. These observations, together with certain characteristics of constant-joining region usage of both TCR genes (a preference for rearrangement into the C beta 2 and C gamma 1 genes), distinguishes these "inappropriate" rearrangements from those found in T-ALL and suggests that they have arisen through a differentiation arrest which is not part of a normal T cell developmental program.
Leukemia 1988 Jan
PMID:Correlation of immunophenotype with rearrangement of T cell antigen receptor beta and gamma genes in acute lymphoblastic leukemia of adults. 325 38

The nature of the cells in 21 cases of acute leukaemia with blasts which were undifferentiated by light microscopy criteria was investigated by immunophenotyping, ultrastructural cytochemistry and DNA analysis. Two groups of cases were recognized. Fourteen cases were negative with B and T lymphoid markers and expressed one or two myeloid antigens detected by the monoclonal antibodies (McAb) MCS2 (CD13) and MY9 (CD33). Peroxidase activity was demonstrated at ultrastructural level by the method of Roels on unfixed cells in eight out of 10 cases; rearrangement of the immunoglobulin (Ig) genes was demonstrated in one of the three cases investigated. These cases are proliferations of early, MO, myeloblasts which can only be recognized by immunological and ultrastructural cytochemical methods. The remaining seven cases revealed a complex phenotype with expression of myeloid and lymphoid antigens. Peroxidase activity was detected in blasts from two cases with rearrangement of the Ig-heavy chain gene; in one of them the T cell receptor beta and gamma chain genes were also found in rearranged configuration. This group comprises cases of biphenotypic and mixed acute leukaemia which probably involve multipotent stem cells. This study demonstrates that the expression of myeloid antigens on blast cells parallels closely the presence of peroxidase activity and that lymphoid markers correlate with gene rearrangements at DNA level. Our findings are reassuring with respect to the specificity of the antimyeloid McAb for the diagnosis of cases which are unclassifiable by conventional methods.
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PMID:The role of ultrastructural cytochemistry and monoclonal antibodies in clarifying the nature of undifferentiated cells in acute leukaemia. 339 Mar 93


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