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Query: UMLS:C0596978 (Leukemia)
 15,069 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The t(9;11)(p21;q23) has been associated with characteristic clinical features and a superior treatment outcome in previously untreated pediatric acute myeloblastic leukemia (AML), but has not been well studied in children with secondary AML. This translocation was detected in 6.7% of de novo and 46% of secondary AML patients treated at St Jude Children's Research Hospital over an 11-year period. Clinical, immunophenotypic, and morphologic characteristics were examined for the cases of t(9;11) secondary AML (n = 12) and compared with findings for children with t(9;11) de novo AML (n = 12). Patients with t(9;11) secondary AML were older at diagnosis, had higher hemoglobin levels, and central nervous system leukemia or hepatosplenomegaly was less frequent. These differences probably reflect survival of the first malignancy and close clinical scrutiny during post-treatment follow-up. Whereas the t(9;11)(p21;q23) occurred exclusively in the French-American-British (FAB) M5 subtype in de novo AML, the FAB M0 and M4 subtypes were also represented in secondary cases. The complete remission rate was somewhat higher for the de novo AML group (91 vs 58%; p = 0.16); their event-free survival was clearly superior to that for children with t(9;11) secondary AML (p = 0.003). Host differences related to the previous malignancy or its treatment could explain the poorer clinical outcome for patients with t(9;11) secondary AML. Alternatively, there could be critical differences at the translocation site or additional, hidden molecular events, that explain the different outcomes.
Leukemia 1992 Jun
PMID:Translocation t(9;11)(p21;q23) in pediatric de novo and secondary acute myeloblastic leukemia. 160 90

We recently developed a new progenitor assay using murine fetal liver cells that provides a source of pluripotent progenitors, bipotent progenitors, and committed macrophage, megakaryocyte, erythroid, and mast cell progenitors. This clonal cell culture system was used to examine the direct effects of Harvey sarcoma virus on murine hemopoietic progenitors. Very large erythroid colonies containing 100,000 to 200,000 cells were seen in the infected group. Only small erythroid colonies were seen in the uninfected control cultures. The cells in the large erythroid colonies from infected cultures expressed the ras gene as demonstrated by immunofluorescence with a monoclonal antibody to p21, the ras gene product. The infected cells were not immortal since they did not yield secondary colonies upon replating. Sequential observation of individual colonies showed that maturation was not blocked by infection with the virus. The size of other colony types, including granulocyte/macrophage, mast cell, and mixed, was unaffected even though some of these colonies expressed the ras gene. Thus, infection with Harvey sarcoma virus appears to give a growth advantage primarily to committed erythroid progenitors.
Leukemia 1990 Mar
PMID:Enhancement of the proliferation of murine fetal liver erythroid progenitors by infection with Harvey sarcoma virus. 215 15

We have studied the immunophenotypic and genotypic characteristic of acute nonlymphoblastic leukemias (ANLL) in infants aged less than one year. Sixty-four percent of cases (16/25) showed a myeloid or myelomonocytic differentiation pattern and 10 of these were classified as FAB M5 (7 M5a, 3 M5b). Only seven of the latter cases expressed the CD14 antigen. Acute megakaryocytic leukemia with a high number of glycoprotein IIb/IIIa or IIIa positive blasts were identified in five patients. Erythroleukemia with a high percentage of rather mature glycophorin A positive erythroblasts were diagnosed in two infants. Cytogenetic studies were successfully performed in all 20 cases investigated. Abnormalities involving chromosome 11 were present in 10 of 17 patients with an abnormal karyotype including five cases with a t(9;11)(p21;q23). Immunoglobulin (Ig) and T cell receptor (TCR) gene analyses were performed in 20 patients. A rearrangement of Ig heavy chain sequences was detected in five cases (20%), one of whom exhibited multiple rearranged fragments. Three of these patients showed additional TCR delta-chain gene rearrangements, while Ig kappa, TCR beta- as well as TCR gamma-chain genes showed a germline configuration in all cases analyzed. Our study confirms the high incidence of myelomonocytic and monoblastic subtypes in infants with ANLL, which are particularly closely associated with chromosome 11 abnormalities. However, we also observed an unexpected high frequency of megakaryoblastic leukemias as well as erythroleukemias. As previously reported for ALL in infants, ANLL of infancy shows a similar heterogeneity regarding phenotypic and genotypic features.
Leukemia 1989 Oct
PMID:Phenotypic and genotypic heterogeneity in infant acute leukemia. II. Acute nonlymphoblastic leukemia. 277 87

Sera from 11 Japanese patients with hairy cell leukemia and 4B122, an anti-hairy cell serum produced by the authors, were surveyed by Western blot analyses for cross-reacting antibodies to human T cell leukemia virus (HTLV)-I and -II virions released, respectively, from Lma-66 and Mo-T cell lines. Sera from the majority of the patients showed positive reactions with p15, p19, and/or p24 of HTLV-I and with p21 and/or p22 or HTLV-II. 4B122 was weakly cross-reactive with HTLV-II but not with HTLV-I. These results militate against the involvement of HTLV-I or -II but may implicate a role by a cross-reacting, previously unrecognized retrovirus in the pathogenesis of hairy cell leukemia in Japanese patients.
Leukemia 1987 Apr
PMID:Cross-reacting antibodies to human T cell leukemia virus-I and -II in Japanese patients with hairy cell leukemia. 282 19

Clinical, hematological, and cytogenetic data of 32 patients with loss of part of the short arm of chromosome 9 (9p-) are reviewed. There were 20 acute lymphoblastic leukemia (ALL), seven non-Hodgkin lymphoma (NHL), three acute myeloid leukemia, one refractory anemia with excess blasts in transformation, and one chronic myeloid leukemia (CML) in blast crisis. The cytogenetic findings were heterogeneous: 13 cases of del(9)(p21), among them four as sole karyotypic change; five cases of del(9)(p12), three of them as sole karyotypic change; four patients with i(9q), three with unbalanced translocations involving 9p12; and seven with unbalanced translocations involving 9p21. In addition, 10 patients showed known specific translocations for determined subgroups of ALL, NHL, and CML. The immunological phenotypes in the 20 ALL patients were common ALL (35%), pre-B-ALL (35%), B-ALL (5%), T-ALL (15%), and null ALL (10%). Three NHL were of T cell origin and the others of B cell origin. No specific association between the karyotypic change, immunophenotype, and clinical presentation could be ascertained for patients with ALL, acute myeloid leukemia, CML in blast crisis, and B-NHL. In T-NHL, three children with deletion of 9p, T immunoblastic lymphoma originating from common thymocyte and presenting with a mediastinal mass and pleural effusion may constitute a definite subgroup with good prognosis. All other cases had a poor outcome. Previously suggested association of 9p- with T-ALL and "lymphomatous features" was not confirmed.
Leukemia 1987 Jul
PMID:Abnormalities of the short arm of chromosome 9 with partial loss of material in hematological disorders. 331 44

Point mutations of p21 Ras proteins correlate with many human malignancies. To determine whether the mutations of Ras proteins generate immunogenic determinants which can be recognized by T cells and possibly serve as targets for immunotherapy, we studied the murine T helper responses to synthetic Ras peptides corresponding to amino acids 1-23 of normal or mutant Ras protein. Immunization of C3H/He and B10.BR mice with Ras peptides containing a valine mutation at position 12 stimulated MHC class II-restricted T helper cells which recognised specifically the Ras mutation. Surprisingly C57BL/10 mice generated T helper responses not only against mutant but also against normal Ras peptides. Importantly, natural processing of Ras protein was found to generate the epitopes recognized by the peptide-induced T cells.
Leukemia 1993 Aug
PMID:T cell recognition of a point mutation in the P21 Ras protein. 768 74

Seven patients with acute leukemia and translocation involving band 11q23 have been studied by fluorescence in situ hybridization (FISH) using YAC probes spanning the HRX gene. While hybridization signal was split by translocation between the rearranged 11 and the partner chromosomes in five patients, only one signal on the derivative 11 was observed in two patients, one with t(9;11)(p21-22;q23) and the other with t(6;11)(q27;q23). Having shown that HRX was rearranged in these two cases, the distal part of 11q23 was investigated using other YACs containing markers for this region. This showed that a 600-700 kb deletion, distal to the HRX breakpoint cluster region, had occurred in the two cases. This study supports the notion that the 5' end of HRX is the important part in the chimeric genes resulting from 11q23 translocations and suggests that deletions of the 3' part are not uncommon.
Leukemia 1994 Apr
PMID:Hunting 11q23 deletions with fluorescence in situ hybridization (FISH). 815 54

p16 INK4A and/or p15 INK4B genes are frequently deleted in leukemias and other cancers. We have established a novel pre-B acute lymphoblastic leukemia (ALL) cell line (JKB2) with a chromosomal translocation between 9p2l and 14q32, on which p16INK4A/p15INK4B and heavy chain immunoglobulin (Ig) genes, respectively, are located. Homozygous deletions of P16INK4A/p15INK4B genes in JKB2 cells were confirmed by polymerase chain reaction, and their protein products were not detectable by Western blotting. Therefore JKB2 is the first example of an immunoglobulin heavy chain translocation associated with deletions of these genes. In JKB2 cells, cyclin-dependent kinase(CDK)4 and CDK6 formed complexes with cyclin D, due to the lack of p16, triggering phosphorylation of retinoblastoma protein (pRB) and continuous cell proliferation. Moreover, the growth of JKB2 cells was partially inhibited by TGF beta or IL-7, accompanied by decreased CDK4 and CDK6 expression, increased p2l and p27 expression, decreased p27 binding to CDK4/CDK6, and increased binding of p27 to CDK2. In addition, IL-7 both inhibited proliferation and induced differentiation of JKB2 cells. These studies suggest that a t(9;14)(p21;q32) chromosomal translocation can result in deletion of both p16 INK4A and p15 INK4B genes in pre-B ALL, and that the JKB2 cell line therefore provides a model for the study of leukemogenesis related to abnormalities in chromosome 9p2l. Moreover, they suggest that TGF-beta can, suppress JKB2 cell growth in a p15-independent mechanism.
Leukemia 1996 Oct
PMID:A novel pre-B acute lymphoblastic leukemia cell line with chromosomal translocation between p16(INK4A)/p15(INK4B) tumor suppressor and immunoglobulin heavy chain genes: TGFbeta/IL-7 inhibitory signaling mechanism. 884 92

Cyclin-dependent kinase inhibitors (CDKIs) can be classified into two groups based on the structure of the proteins. One group includes the p21 (CIP1, WAF1, CAP20), p27 (Kip1), and p57 (Kip2) CDKIs, which contain a homologous amino-terminal cyclin-dependent kinase (cdk) inhibitory domain. The p16 (INK4A), p15 (INK4B), and p18 (INK4C) CDKIs, which have an ankyrin repeat motifs, belong to the other group. The p16 and p15 CDKI genes are very frequently altered in a variety of cancers including hematopoietic malignancies. The p19 (INK4D) gene is a newly cloned CDKI which belongs to the latter group. To determine if p19 genetic alterations play a role in hematopoietic malignancies, we examined DNA from 45 childhood newly diagnosed acute lymphocytic leukemias (ALLs), 30 acute myeloblastic leukemias (AMLs), 10 chronic myelocytic leukemias (CMLs), 45 adult T cell leukemias (ATLs), 70 non-Hodgkin's lymphomas (NHLs), and 20 multiple myelomas (MM) as well as 14 ALL, 20 AML, two ATL, and five lymphoma cell lines. Using Southern blot analysis, one homozygous deletion of the p19 gene was detected in a human immunodeficiency virus (HIV)-related Burkitt-like lymphoma sample. No point mutations in any of the samples were found by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. Our investigation suggests that alterations of p19 do not play an important role in the development of most hematopoietic malignancies.
Leukemia 1996 Dec
PMID:Alterations of the cyclin-dependent kinase inhibitor p19 (INK4D) is rare in hematopoietic malignancies. 894 28

Transforming growth factor-beta (TGF-beta) has been found to block the progression of the cell-cycle by up-regulating a Cdk inhibitor, p15, only in epithelial cells; on the other hand, wild-type p53 was shown to activate transcriptionally the gene for another Cdk inhibitor, p21. The regulatory effects of TGF-beta on hematopoietic tissues is poorly understood. Hence, we investigated the effect of TGF-beta on hematopoietic progenitor cells in p53-deficient mice to determine whether an inhibitory signal from TGF-beta is linked to p53 in hematopoietic regulation. We found that the proliferation of megakaryocyte-progenitors (CFU-Mk) in our wild-type mice was markedly inhibited by TGF-beta. Contrary to an earlier report, an erythroid and a granulocyte-macrophage progenitor, stimulated by IL-3, were not significantly inhibited, whereas TGF-beta also completely inhibited the growth of high-proliferative potential progenitor cells (HPP-CFC) in the marrow of mice with 5-fluorouracil (5FU), as reported. It is interesting that in the p53-deficient mice, the inhibitory action of TGF-beta on the HPP-CFC was incompletely abolished. The response curve we obtained for graded doses of TGF-beta suggests that there is, at least, a subpopulation of HPP-CFC which is less sensitive to the regulation by TGF-beta. In contrast to HPP-CFC, the CFU-Mk, which TGF-beta inhibited only in wild-type mice not treated with 5FU, remained inhibited in the p53-deficient strain. Thus, HPP-CFC might be regulated by TGF-beta through their signal pathways which are linked to p53.
Leukemia 1997 Feb
PMID:A fraction unresponsive to growth inhibition by TGF-beta among the high-proliferative potential progenitor cells in bone marrow of p53-deficient mice. 900 87


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