Publications by authors named "Ayala-Sanchez M"

Tyrosine kinase inhibitors (TKI) have become a first-line treatment for chronic myeloid leuakemia (CML). TKIs efficiently target bulk CML cells; however, they are unable to eliminate the leukaemic stem cell (LSC) population that causes resistance and relapse in CML patients. In this study, we assessed the effects of parthenolide (PTL) and dimethyl amino parthenolide (DMAPT), two potent inhibitors of LSCs in acute myeloid leukaemia (AML), on CML bulk and CML primitive (CD34 lin ) cells.

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In this study, we determined the gene expression profiles of bone marrow-derived cell fractions, obtained from normal subjects and Chronic Myeloid Leukemia (CML) patients, that were highly enriched for hematopoietic stem (HSCs) and progenitor (HPCs) cells. Our results indicate that the profiles of CML HSCs and HPCs were closer to that of normal progenitors, whereas normal HSCs showed the most different expression profile of all. We found that the expression profiles of HSCs and HPCs from CML marrow were closer to each other than those of HSCs and HPCs from normal marrow.

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Several novel compounds have been developed for the treatment of different types of leukemia. In the present study, we have assessed the in vitro effects of Casiopeina III-Ea, a copper-containing small molecule, on cells from patients with Chronic Myeloid Leukemia (CML). We included primary CD34 Lineage-negative (Lin) cells selected from CML bone marrow, as well as the K562 and MEG01 cell lines.

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Background: Chronic myeloid leukemia (CML) is one of the most frequent hematopoietic malignancies in the elderly population; however, knowledge is limited regarding the genetic factors associated with increased risk for CML. Polymorphisms affecting microRNA (miRNA) biogenesis or mRNA:miRNA interactions are important risk factors in the development of different types of cancer. Thus, we carried out a case-control study to test the association with CML susceptibility of gene variants located in the miRNA machinery genes AGO1 (rs636832) and GEMIN4 (rs2740348), as well as in the miRNA binding sites of the genes BRCA1 (rs799917) and KRAS (rs61764370).

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Chronic Myeloid Leukemia (CML) is sustained by a small population of cells with stem cell characteristics known as Leukemic Stem Cells that are positive to BCR-ABL fusion protein, involved with several abnormalities in cell proliferation, expansion, apoptosis and cell cycle regulation. Current treatment options for CML involve the use of Tirosine Kinase Inhibitor (Imatinib, Nilotinib and Dasatinib), that efficiently reduce proliferation proliferative cells but do not kill non proliferating CML primitive cells that remain and contributes to the persistence of the disease. In order to understand the role of Cyclin Dependent Kinase Inhibitors in CML LSC permanence after TKI treatment, in this study we analyzed cell cycle status, the levels of several CDKIs and the subcellular localization of such molecules in different CML cell lines, as well as primary CD34(+)CD38(-)lin(-) LSC and HSC.

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Background: Treatment recommendations have been developed for management of patients with chronic myeloid leukemia (CML).

Methods: A 30-item multiple-choice questionnaire was administered to 435 hematologists and oncohematologists in 16 Latin American countries. Physicians self-reported their diagnostic, therapeutic, and disease management strategies.

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Chronic Myeloid Leukaemia (CML) is a clonal disease, originated at the level of Hematopoietic Stem Cells (HSC) and characterized by the presence of the Philadelphia (Ph) chromosome and its oncogenic product p210(BcrAbl). Such a protein has been shown to be essential for malignant transformation, since it is capable of altering cell adhesion, proliferation and apoptosis. Historically, CML has been treated by using different approaches: arsenic (in the early days), a variety of chemical agents (busulfan, hydroxyurea, cytarabine), cytokines (IFN-alpha, IFNalpha-PEG), hematopoietic cell transplant (HCT), and more recently drugs generated by design (imatinib, nilotinib, dasatinib).

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Between June 2003 and November 2004, we collected mobilized peripheral blood units from 29 patients with non-Hodgkin's lymphoma and multiple myeloma for autologous peripheral blood stem cell transplantation. They received granulocyte colony-stimulating factor (G-CSF) (16 micro g/kg/day) for a total of 5 days. Immediately before and 3 h after the fourth and fifth dose of G-CSF, we performed flow cytometry analysis to quantify: T cells (CD3+CD4+, CD3+CD8+), B cells (CD19+), NK cells (CD3-CD16+CD56+), NKT cells (CD3+CD16+CD56+), type 1 dendritic cells (DC1) (lin-HLA-DR+CD11c+), type 2 dendritic cells (DC2) (lin-HLA-DR+CD123+), regulatory T cells (Tregs) (CD4+CD25+), and activated T cells (CD3+HLA-DR+).

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To analyze the relationship between the cellular composition of peripheral blood allografts and clinical outcome, we performed a prospective study in 45 adult patients who underwent allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT) from a histocompatibility leukocyte antigen identical sibling donor for different hematological malignancies. The dose of CD34+, CD3+, CD4+, CD8+, and CD19+ lymphocytes, natural killer (NK) cells, natural killer T (NKT) cells, type 1 and type 2 dendritic cells (DC1 and DC2), as well as regulatory T (Treg) lymphocytes was analyzed. All patients were conditioned with busulphan and cyclophosphamide (BuCy2) +/- VP-16 and received a short course of methotrexate and cyclosporin-A as graft-versus-host disease (GVHD) prophylaxis.

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In this study, we have assessed the in vitro growth of hematopoietic progenitor cells (HPC) from chronic myeloid leukemia (CML) patients that have recovered after different treatments. Bone marrow cells were obtained from 33 CML patients, including patients at diagnosis, before treatment (n=12), and patients that have achieved hematological remission (and in most cases a major cytogenetic response) after different therapeutic procedures (n=21), including patients treated with Interferon-alpha (IFN; n=5), imatinib mesylate (IMATINIB; n=8) and patients that received an allogeneic hematopoietic cell transplant (HCT; n=8). Marrow cells were enriched for CD34(+) cells and cultured in a serum- and stroma-free liquid culture system, supplemented with a combination of 8 recombinant cytokines.

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We prospectively conducted a quantitative and phenotypic analysis of T, B, natural killer (NK), NKT, type 1 and 2 dendritic cells (DC), and regulatory T cells, before and after mobilization with intermediate doses of granulocyte colony-stimulating factor (G-CSF) (16 microg/kg per day). Between November, 2003, and December, 2004, we collected stem cells from 25 HLA identical sibling donors for allogeneic hematopoietic stem cell transplantation. Before mobilization and 3 h after the fourth and fifth doses of G-CSF, blood samples were taken for blood counts and flow cytometry.

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Reduced intensity conditioning (RIC) have allowed the application of transplantation to older patients and to patients with underlying medical problems. Between October, 1999, and June, 2003, 61 patients with acute leukemia or chronic myeloid leukemia received allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT) from HLA-identical siblings. Thirty-four were conditioned with myeloablative protocols and twenty-seven with RIC regimens.

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Between December 1993 and November 2001, 30 patients with chronic myeloid leukemia who relapsed after stem cell transplantation were studied. Seventeen patients were not treated before donor lymphocyte infusion (DLI), eight patients received interferon-alpha (IFN-alpha), and five underwent chemotherapy. The method of DLI was the bulk dose regimen.

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Problem: It has been suggested that type of chimeric mRNA is associated with differences in the clinical and hematologic characteristics of chronic myeloid leukemia (CML). However, prognostic value of type of chimeric mRNA bcr-xabl (b3a2 or b2a2) is still controversial.

Methods: We analyzed 97 cases of Philadelphia-positive CML to determine mRNA type by reverse-polymerase chain reaction (RT-PCR) and its relationship with clinical features.

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Introduction: Chronic myeloid leukemia (CML) is characterized by a chromosomal translocation t(9; 22) resulting in the chimeric ber-abl oncogene that encode for the p210 protein which has an increased tyrosine kinase activity. The fusion part of this protein contains a novel aminoacid sequence. If peptides derived from this leukemia-specific part of p210 are expressed in the context of HLA molecules on malignant cells this may elicit immunologically specific responses.

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Chronic myeloid leukemia (CML) is a hematological neoplasia that results from the transformation of a hematopoietic stem cell. It is characterized by the expansion of the myeloid lineage, which results in the accumulation of mature and immature granulocytes in peripheral blood and bone marrow. However, when CML marrow cells are cultured in Dexter-type long-term cultures (LTMC) hematopoiesis is defective and can be sustained for only a few weeks.

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Primary plasma cell leukemia (PPCL) is a rare form of disease accounting for 1-2 percent of myelomas. Between September 1990 and November 2000, among 540 patients with myeloma studied, 24 fulfilled the criteria of PPCL (4.4 percent).

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Background: Bone marrow transplantation (BMT) is the therapy of choice for patients with chronic myeloid leukemia (CML) who have a human leukocyte antigen (HLA)-identical donor and are under 50 years of age.

Methods: Here, 45 patients with CML were treated with busulfan (Bu) 16 mg/kg and cyclophosphamide (Cy) 120 mg/kg before allogeneic BMT from an HLA-identical sibling 27 (60%) or a 1-antigen mismatch donor 18 (40%). Eighteen patients (40%) were in the early chronic phase (CP) and 27 (60%) in late CP.

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Between August 1994 and June 1999, 56 patients were prospectively randomized to receive ifosfamide 10 g/m2 + GM-CSF 5 microg/kg/day (IFO+GM-CSF n = 28) and cyclophosphamide 4 g/m2 + GM-CSF 5 microg/kg/day (CY+GM-CSF n = 28). Both groups were comparable for age, gender, diagnosis, disease stage and previous chemotherapy. The IFO+GM-CSF group demonstrated a shorter median interval between therapy and apheresis (10 days (8-14) vs 13 days (8-25) P = 0.

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In the present study, we assessed the clinical effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in the treatment of refractory, grade III-IV hemorrhagic cystitis (HC) in six patients who underwent bone marrow transplantation (BMT). These were four males and two females, aged 24-40 years (median age 30.5 years).

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A 24-year-old woman with CML underwent allogeneic BMT in August 1995 from a one-antigen HLA mismatched brother. Conditioning included BuCy2 and CsA and MTX were used to prevent GVHD. In July 1997 she developed right leg pain, lytic bone lesions of distal femur and a solid mass of soft tissue.

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