Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598766 (leukemogenesis)
 4,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homozygous loss of alleles of the retinoblastoma susceptibility locus (RB1) has been implicated in the onset of many different solid tumors. Heterozygous deletions of chromosome 13q14, the region containing the RB1 locus, have been observed by us in several subvariants of leukemia and preleukemia. We examined four cases of leukemia and one case of preleukemia for homozygous inactivation of the RB1 locus; in at least one case, evidence supports the concept that homozygous loss of both alleles of RB1 was an important step during leukemogenesis.
Cancer Genet Cytogenet 1990 Oct 01
PMID:Structural alterations at the putative retinoblastoma locus in some human leukemias and preleukemia. 239 69

Although phenotypic heterogeneity of childhood T-cell acute lymphocytic leukemia (T-ALL) which bear receptors for sheep red blood cells (E-rosettes) and/or T-cell-associated antigens has been reported, there are certain clinical features which are shared by most patients. A mediastinal mass is one of the most characteristic presentations in this particular disorder. This report describes four children with ALL, who presented with a mediastinal mass. Three patients were E-rosette-negative and one was E-rosette-positive. Individual surface phenotypes, defined by a panel of monoclonal antibodies, were quite different. Since Ig gene organization is an essential property of cells of B-lineage, it was surprising to find that analysis of genomic DNA revealed immunoglobulin (Ig) gene rearrangements in two of them. These findings suggest that there is significant heterogeneity even among those leukemias associated with a mediastinal mass, and that a mediastinal mass may not clearly indicate origin from cells of T-lineage. This heterogeneity may reflect differences in leukemogenesis and may have prognostic and therapeutic implications.
Cancer 1985 Aug 01
PMID:Phenotypic heterogeneity at the DNA level in childhood leukemia with a mediastinal mass. 240 36

The immunological and cytochemical phenotypes of five primary feline lymphomas and six feline lymphoma lines are reported. Thymic lymphomas induced by the Rickard strain of FeLV (FeLV-R) are of prothymocyte or (immature) cortical thymocyte origin, as these express terminal deoxynucleotidyl transferase, the guinea pig erythrocyte rosette receptor, Ia antigens, partial cortisone sensitivity, and nonspecific esterase. Lymphomas associated with other strains of FeLV form rosettes with guinea pig erythrocytes, frequently have Ia antigens and cytoplasmic nonspecific esterase, and probably originate from helper T-cells, monocyte/macrophages, or null cells. These data belie previous conclusions that FeLV leukemogenesis is restricted to mature T-cells; rather, the considerable heterogeneity in the surface and cytochemical phenotype of feline lymphomas probably reflects transformation of multipotent lymphoid or monocytoid precursors in the bone marrow by FeLV.
Cancer Res 1989 Jan 15
PMID:Feline lymphomas: immunological and cytochemical characterization. 253 58

While activation of the protooncogene c-N-ras is observed regularly in acute myelogenous leukemia, amplification of c-myc in AML cells or derived lines is uncommon. In particular, concurrent ras/myc activation, which has been shown to be critical in several elegant models of malignancy, has been demonstrated in a very small number of human tumors or derivative cell lines. A cell line, RED-3, is described which was derived from cells of a patient with aggressive acute leukemia which exhibits many markers of lineage infidelity. DNA from this cell line contains an activating point mutation of c-N-ras as well as 20-30-fold amplification of c-myc. After HL-60, this is the second example of ras/myc activation in AML derived cells and demonstrates that this lesion is not unique to HL-60. Rather, it may be important in leukemogenesis in a small proportion of AML patients.
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PMID:c-myc amplification coexistent with activating N-ras point mutation in the biphenotypic leukemic cell line RED-3. 265 2

Friend virus clearly provides an important model for understanding the molecular biology of cancer. Moreover, the most important aspects of the erythroleukemia can be caused by a single SFFV infection in the absence of any helper virus. The SFFV env gene encodes a membrane glycoprotein, gp55. This glycoprotein, when expressed on erythroblast surfaces, causes a constitutive mitogenesis. However, SFFV infections only rarely increase the cell's self-renewal capability or abrogate its commitment to differentiate. Therefore, the consequence of infection is initially a polyclonal erythroblastosis. This polyclonal proliferation usually leads to cell differentiation and to recovery unless helper virus is present to cause continuing infection of new erythroblasts. Extremely rare SFFV proviral integrations, however, result in abrogation of the cell's commitment to differentiate and in the concomitant acquisition of cell immortality. These immortalizing proviral integrations occur at only a small number of sites in the mouse genome. Therefore, the mitogenic and immortalizing stages of erythroleukemia are now known to be caused by discrete genetic events--the first involving the SFFV env gene and the second involving the rare proviral integration sites. In early investigations of Friend virus, the first stage always preceded the second stage by at least several weeks. Now it is known that this delay in onset of the second stage is caused solely by statistics. Every SFFV-infected erythroblast is mitogenically activated, yet only rarely does the SFFV proviral integration produce immortality. Both steps in leukemogenesis can be caused simultaneously in an erythroblast by a rare single SFFV proviral integration. There has been an explosion of interest in retroviral env gene-mediated pathogenesis. Such pathogenesis has been recently associated with most of the naturally transmitted retroviral diseases including AIDS. Such pathogenesis involves in different viruses immunosuppression, anemia, neuropathy, and leukemia (Mathes et al. 1978; Simon et al. 1984, 1987; Weiss et al. 1985; Lifson et al. 1986; Riedel et al. 1986; Sitbon et al. 1986; Sodroski et al. 1986; Mitani et al. 1987; Schmidt et al. 1987; Klase et al. 1988; Overbaugh et al. 1988a, b). The shuffling and dynamic env gene rearrangements that have been associated with murine retroviral leukemogenesis have also now been seen in FeLV-FAIDS and HIV (Fisher et al. 1988; Overbaugh et al. 1 t88b; Saag et al. 1988; Tersmette et al. 1988). Friend virus provides an important established example of such env gene pathogenesis. Although we still do not understand precisely how gp55 causes erythroblast mitosis, workers in this field have discovered important clues that may lead to answers.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Molecular biology of Friend viral erythroleukemia. 268 47

A case of acute myelocytic leukemia (AML-M2) with a late appearance of Philadelphia chromosome (Ph1) is presented. Chromosome analysis revealed a normal karyotype at the time of diagnosis and for 23 months, when hematological relapse occurred, accompanied by abnormal clones, 46, XX, t(9;22) (q34;q11) (78%) and 45,XX, -16, t(9;22) (q34;q11), del (5) (q13q31) (22%). The patient died of GVHD after bone marrow transplantation. Molecular analysis confirmed bcr gene rearrangement in the cells with Ph1 chromosome. Acquisition of Ph1 chromosome during the course of hematological malignancies other than CML is extremely rare. This case is undoubtedly important for the understanding of leukemogenesis and the evolution of leukemia clones. The authors discussed possible mechanisms of Ph1 acquisition in the late stages of AML.
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PMID:[Late appearance of Philadelphia chromosome with bcr gene rearrangement in an acute myelocytic leukemia patient]. 269 64

Leukemic blast cells are thought to arise from clonal expansion of a single transformed hematopoietic cell. This generality is supported by the rarity of convincing reports on acute myeloblastic leukemia (AML) with two karyotypically independent clones. Relying on sequential cytogenetic analyses, we identified such clones in two children with relapsed AML. The first case, classified as M2 leukemia in the French-American-British (FAB) classification system, had a t(8;21) (q22;q22) at diagnosis; 16 months later, at relapse, the leukemic cells had uniform morphologic features similar to those observed at diagnosis, except that two independent clones were present: one with the original t(8;21) and the other with t(11;22)(q23;q13) [corrected]). The second case was initially classified as FAB M1 leukemia with a t(8;21) (q22;q22). At relapse, 16 months later, the blast cells appeared morphologically uniform and similar to the diagnostic specimen; however, in addition to the original t(8;21) clone, there was a t(1;11) (p32;q23) [corrected]. These findings suggest that separate leukemogenic events affecting different progenitor cells can occur in rare cases of AML. The presence of two karyotypically independent clones could also be explained by multistep leukemogenesis; that is, more than one cell from a common pool of preleukemic cells could be affected by the transforming event, resulting in two independent clones. Alternatively, in light of recent reports of therapy-related leukemias with an 11q23 translocation, the new independent clone in these two patients could represent a therapy-related secondary malignancy. Thus, 11q23 translocations may occur preferentially in stem cells that are more susceptible to treatment-induced malignant transformation.
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PMID:Two karyotypically independent leukemic clones with the t(8;21) and 11q23 translocation in acute myeloblastic leukemia at relapse. 271 98

Five patients with acute nonlymphocytic leukemia (ANLL) with chromosomal aberrations involving bands 9q21-q22 are described. The abnormalities were an interstitial deletion in two cases of ANLL FAB type M4 and M4 with eosinophilia, a terminal deletion in two cases of M4 and M5 type ANLL, and a translocation in an M2 ANLL. A review of reported cases of ANLL with abnormalities of chromosome 9 revealed a clustering of breaks at the region 9q21-q22, suggesting a possible role for these bands in leukemogenesis.
Cancer Genet Cytogenet 1989 May
PMID:Involvement of bands 9q21-q22 in five cases of acute nonlymphocytic leukemia. 273 Nov 48

CBA/N (xid-) mice failed to develop erythroleukemia when inoculated with an NB-tropic, anemia-causing Friend virus stock (FVA), while Fv-2ss mouse strains succumbed rapidly to the characteristic Friend disease, even after a virus dose 30-fold lower than that given to CBA/N mice. Immunization with bacterial antigens or with spleen cell allografts prior to FVA inoculation rendered CBA/N mice highly susceptible to FVA. Transplantation studies confirmed that non-immunized CBA/N mice were able to both support erythroleukemic cells and permit erythroleukemic transformation, thus arguing against host defense mechanisms as a cause of resistance. On the basis of early erythroid progenitor cell sensitivity to hydroxyurea in vivo, the CBA/N strain appeared to have the FVA sensitive genotype (Fv-2ss). These results imply that CBA/N mice are not intrinsically resistant to FVA and that an as yet unknown type of immunological activity, evoked both by various immunizations and allogeneic transplantation, is required for Friend leukemogenesis in this immunodeficient inbred strain. These findings further suggest that the erythroid target cells transformed by Friend viruses are influenced by immunological activity.
Cancer Res 1986 Jul
PMID:Resistance to erythroleukemia in immunodeficient xid- CBA/N mice with susceptibility after immune stimulation. 287 24

Human T-cell leukemia/lymphoma virus I (HTLV-I) is known to be associated with adult T-cell leukemia/lymphoma (ATL) as an etiological agent. The mechanism of leukemogenesis by HTLV, however, is still obscure. Two hypotheses have been proposed concerning abnormalities in IL-2 production and its receptor (Tac antigen) expression based on the experimental observations of IL-2-dependent ATL cell lines. In this study, we examine these hypotheses by using 3 leukemic T-cell lines from 3 Japanese patients with ATL. These cell lines were cultivated and established without addition of IL-2 to the culture medium. Cell-surface phenotype analysis by immunofluorescence with monoclonal antibodies (MAbs) and IL-2 binding assays revealed that one of the ATL cell lines, HPB-ATL-2, expresses only a minimal amount of IL-2 receptor (IL-2-R) on the cell surface and binds less radiolabelled human recombinant IL-2 than the other highly Tac-positive cell lines. Expression of Tac antigen in all ATL cell lines was not affected by IL-2, anti-Tac MAb or the tumor-promoter phorbol ester in the culture medium. The culture supernatant from these cell lines showed no IL-2 activity toward Con-A-stimulated human peripheral blood lymphocytes, and their growth was not affected by additional IL-2 in cultures. IL-2-independent growth and constitutive expression of its receptors on the cell surface were evident in our ATL cell lines. However, dense expression of IL-2 receptors was not essential for stimulation of leukemic proliferation of T cells by HTLV-I. Trans-activation of the PX40 gene product of HTLV-I for activation of IL-2-R gene might not be coincidentally associated with stimulation for cell proliferation.
Int J Cancer 1986 Aug 15
PMID:IL-2- and IL-2-R- independent proliferation of T-cell lines from adult T-cell leukemia/lymphoma patients. 287 15


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