Thesis (Ph.D.)--Medical University of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: Manohar Ratnam. Includes abstract. Document formatted into pages: iv, 158 p. Title from title page of PDF document. Title at ETD Web site: Modulation of folate receptor beta for drug targeting in acute myelogenous leukemia. Non-Latin script record Bibliography: pages 67-70, 106-109, 127-156.

Thesis (MTech(Medical Technology))--Cape Technikon, Cape Town, 1996 / Haematol.ogical defects observed in cl.onal deletions of mtDNA and the inhibition of mitochondrial function by benzene and chloramphenicol., suggest a role for mtDNA in the pathogenesis of radiation - induced preleukaemia (MDS). The fact that leukaemia cell.s contain abnormal mitochondria and abnormally structured mtDNA, makes it reasonable to assume mtDNA mutations could be central to the pathogenesis of both MDS and l.eukaemia. It was decided to examine MDS patients for the presence of mtDNA length mutations (dimers and cocantameres). Such topol.ogical forms have already been reported in the literature in association with human leukaemia. These steric considerations suggest that mtDNA dimers are probably non-functional due to supercoil.ing. Thus, it was felt that a progressive accumulation of non-functional dimers in the haematopoietic compartment could account for many of the cl.inical. features associated with MDS. Transmission electron microscopy was used to examine haematopoietic mtDNA in the bone marrow of six patients with MDS. Abnormal mtDNA dimer formation was found in al.l instances. The proportional. number of these dimers were found to roughly correlate with the Myeloid/ Erythroid cell. ratio in the bone marrow, and it appeared likely that the dimers were generated in the myeloid compartment during early MDS. Control.l.ed radiation studies were performed on 20 wistar rats in an attempt to elucidate the approximate time when abnormal mtDNA dimer formation occurred, fol.l.owing fractionated gamma or gamma-neutron irradiation. Gamma-irradiated rats demonstrated abnormal mtDNA dimer formation at the time hypoplastic marrow recovery was first observed.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Chromosomal alterations involving the RUNXI or CBFB genes are specifically and recurrently associated with human acute myeloid leukemia (AML). One such chromosomal alteration, a pericentric inversion of chromosome 16, is present in the majority of cases of the AML subtype M4Eo. This inversion joins CBFB with the smooth muscle myosin gene MYH11 creating the fusion CBFB-MYH11. Knock-in studies in the mouse have demonstrated that expression of the protein product of the Cbfb-MYH11fusion, Cbfβ-SMMHC, predisposes mice to AML and that chemical mutagenesis both accelerates and increases the penetrance of the disease (Castilla et al., 1999). However, the mechanism of transformation and the associated collaborating genetic events remain to be resolved. As detailed in Chapter 2, we used retroviral insertional mutagenesis (RIM) to identify mutations in Cbfb-MYH11 chimeric mice that contribute to AML. The genetic screen identified 54 independent candidate cooperating genes including 6 common insertion sites: Plag1, Plagl2, Runx2, H2T23, Pstpip2, and Dok1. Focusing on the 2 members of the Plag family of transcription factors, Chapter 3 presents experiments demonstrating that Plag1 and Plagl2 independently cooperate with Cbfβ-SMMHC in vivo to efficiently trigger leukemia with short latency in the mouse. In addition, Plag1 and PLAGL2 increased proliferation and in vitro cell renewal in Cbfβ-SMMHC hematopoietic progenitors. Furthemore, PLAG1 and PLAGL2 expression was increased in 20% of human AML samples suggesting that PLAG1 and PLAGL2 may also contribute to human AML. Interestingly, PLAGL2was preferentially increased in samples with chromosome 16 inversion, t(8;21), and t(15;17). To define the mechanism by which PLAGL2 contributes to leukemogenesis, Chapter 4 presents studies assessing the role of the Mp1 signaling cascade as a Plagl2 downstream pathway in leukemia development. Using microarray analysis we discovered that PLAGL2 induces the expression of Mp1 transcript in primary bone marrow cells that express Cbfβ-SMMHC and that this induction is maintained in leukemogenesis. We have also performed luciferase assays to confirm that the Mp1 proximal promoter can be directly bound and activated by PLAGL2. Furthermore, we demonstrate increased Mp1 expression leads to hypersensitivity to the Mp1 ligand thrombopoietin (TPO) in PLAGL2/Cbfβ-SMMHC leukemic cells. To test the functional relevance in leukemia formation, we performed a bone-marrow transplantation assay and demonstrate that overexpression of Mp1 is indeed sufficient to cooperate with Cbfβ-SMMHC in leukemia induction. This data reveals that PLAGL2 cooperates with Cbfβ-SMMHC at least in part by inducing the expression of the cytokine receptor Mp1. Thus, we have identified the Mp1 signal transduction pathway as a novel target for therapeutic intervention in AML.

No description available.

O transplante de células tronco hematopoéticas alogênico e autogênico na leucemia mielóide aguda em primeira remissão completa: analise de 62 pacientes. Os pacientes foram submetidos a transplante de células tronco hematopoéticas alogênico e autogênico. Ao final do estudo estavam vivos no alogênico 43,3% e no autogênico 62,5%. Consolidação intensiva teve melhor sobrevida no alogênico. Os pacientes com DECH aguda grau II tiveram melhor sobrevida. Dois pacientes com DECH crônica extensa morreram. Óbito por infecção ocorreu com maior freqüência no alogênico seguido de recidiva. No autogênico a recidiva foi a principal causa de óbito. Morte por toxicidade ocorreu em 47% dos pacientes que foram a óbito no alogênico e em 8,3% no autogênico. Na analise múltipla de Cox a consolidação intensiva e DECH crônica, tiveram significância. / The allogeneic and autologous hematopoietic stem cell transplantation in acute myeloid leukemia in first complete remission: analyses of 62 patients. The patients were submitted to allogeneic and autologous hematopoietic stem cell transplantation. The end of the study were kept alive in allogeneic 43,3% and in autologous 65,2%. Patient in allogeneic who were consolidated had better survival. Patients with acute GVHD grade II had better survival. Two patients with chronic GVHD in intense, died. Infection was the most frequent dead cause in allogeneic following relapse. In autologous the relapse was the principal cause of death. Toxicity occurred in 47% of patients who died in allogeneic and 8,3% in autologous. In cox multiple analyses intensive consolidation and chronic GVHD had significance.

O transplante de células tronco hematopoéticas alogênico e autogênico na leucemia mielóide aguda em primeira remissão completa: analise de 62 pacientes. Os pacientes foram submetidos a transplante de células tronco hematopoéticas alogênico e autogênico. Ao final do estudo estavam vivos no alogênico 43,3% e no autogênico 62,5%. Consolidação intensiva teve melhor sobrevida no alogênico. Os pacientes com DECH aguda grau II tiveram melhor sobrevida. Dois pacientes com DECH crônica extensa morreram. Óbito por infecção ocorreu com maior freqüência no alogênico seguido de recidiva. No autogênico a recidiva foi a principal causa de óbito. Morte por toxicidade ocorreu em 47% dos pacientes que foram a óbito no alogênico e em 8,3% no autogênico. Na analise múltipla de Cox a consolidação intensiva e DECH crônica, tiveram significância. / The allogeneic and autologous hematopoietic stem cell transplantation in acute myeloid leukemia in first complete remission: analyses of 62 patients. The patients were submitted to allogeneic and autologous hematopoietic stem cell transplantation. The end of the study were kept alive in allogeneic 43,3% and in autologous 65,2%. Patient in allogeneic who were consolidated had better survival. Patients with acute GVHD grade II had better survival. Two patients with chronic GVHD in intense, died. Infection was the most frequent dead cause in allogeneic following relapse. In autologous the relapse was the principal cause of death. Toxicity occurred in 47% of patients who died in allogeneic and 8,3% in autologous. In cox multiple analyses intensive consolidation and chronic GVHD had significance.

Thesis (Ph. D.)--Uniformed Services University of the Health Sciences, 2005. / Typescript (photocopy).