losartan-potassium and Leukemia

Topics: Animals; Aspirin; Cell Differentiation; Cell- and Tissue-Based Therapy; Erythropoietin; Graft vs Host Disease; Hematopoiesis; Hematopoietic Stem Cells; Humans; Leukemia; Mesenchymal Stem Cells; Mice; Neoplastic Stem Cells

The in vitro production of recombinant protein molecules has fostered a tremendous interest in their clinical application for treatment and support of cancer patients. Therapeutic proteins include monoclonal antibodies, interferons, and haematopoietic growth factors. Clinically established monoclonal antibodies include rituximab (targeting CD20-positive B-cell lymphomas), trastuzumab (active in HER-2 breast and gastric cancer), and bevacizumab (blocking tumor-induced angiogenesis through blockade of vascular-endothelial growth factor and its receptor). Interferons have lost much of their initial appeal, since equally or more effective treatments with more pleasant side effects have become available, for example in chronic myelogenous leukaemia or hairy cell leukaemia. The value of recombinant growth factors, notably granulocyte colony stimulating factor (G-CSF) and erythropoietin is rather in the field of supportive care than in targeted anti-cancer therapy. Adequately powered clinical phase III trials are essential to estimate the true therapeutic impact of these expensive compounds, with appropriate selection of clinically relevant endpoints and sufficient follow-up. Monoclonal antibodies, interferons, and growth factors must also, and increasingly so, be subjected to close scrutiny by appropriate cost-effectiveness analyses to ensure that their use results in good value for money. With these caveats and under the condition of their judicious clinical use, recombinant proteins have greatly enriched the therapeutic armamentarium in clinical oncology, and their importance is likely to grow even further.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Erythropoietin; Granulocyte Colony-Stimulating Factor; Humans; Intercellular Signaling Peptides and Proteins; Interferons; Leukemia; Lymphoma; Neoplasms; Recombinant Proteins

Eighty percent of children with cancer suffer from anemia at the time of diagnosis. The physiopathology of anemia is complex. Although anemia can be life threatening, its consequences on the physical, psychological and social state of the child are often minimized. Blood transfusion is the main treatment of anemia: its efficacy is immediate but shortlasting, and it involves infectious and hemolytic risks. The human recombinant erythropoietin has been used for more than 25-years, and is often prescribed to adults with cancer and anemia. The human recombinant erythropoietin rHuEPO is nowadays used when blood transfusion is contra-indicated because of religious or cultural considerations, although several promising studies have been conducted about rHuEPO and children with cancer since 1996: it might be soon the preferential alternative treatment to anemia in children with cancer.

Topics: Adolescent; Anemia; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Female; Humans; Infant; Leukemia; Lymphoma; Male; Neoplasms; Neuroblastoma; Recombinant Proteins

Polycythemia vera (PV) is a chronic myeloproliferative disorder due to a haematopoietic stem cell's clonal proliferation. PV is also characterized by independency or hyper sensibility of haematopoietic progenitors to several cytokine as erythropoietin. This acquired disorder is often associated with thrombocytosis, leukocytosis and splenomegaly. Generally, diagnosis remains easy, based on basic clinical and biological abnormalities. Sometimes, positive diagnosis required more sophisticated tests as assay of endogenous erythroid colony, erythropoietin blood level and bone marrow biopsy. Usually natural history of disease remains long with a good quality of life. In some cases complications occur: mainly thrombosis and late myeloid metaplasia with myelofibrosis and acute leukemia. Therapeutic approachs remain complex and difficult to optimize based up on age and disease severity. Treatment searchs for reducing hyper viscosity complications and for avoiding therapeutic induced leukemia.

Topics: Biopsy; Bone Marrow; Diagnosis, Differential; Erythroid Cells; Erythropoietin; Humans; Leukemia; Polycythemia Vera; Quality of Life; Severity of Illness Index

This review summarises the rationale, clinical trial evidence for benefit and potential toxicities of Erythropoietin, Thrombopoietin, Granulocyte Colony Stimulating Factor and Granulocyte-Macrophage Colony Stimulating Factor. Erythropoietin has failed to have a clinical impact on red cell transfusion requirement in very low birth weight infants; it is uncertain whether Thrombopoietin will find a significant clinical role in neonatal thrombocytopenia and there is, as yet, insufficient evidence for the routine use of Granulocyte- or Granulocyte-Macrophage Colony Stimulating Factor to prevent or treat bacterial infection. A number of theoretical risks of haemopoietic growth factor use in neonates have been suggested, but no toxicities have been observed during their clinical use. Exploring the potential for benefit in selected groups of infants should be encouraged.

Topics: Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Cell Growth Factors; Humans; Infant, Newborn; Leukemia; Thrombopoietin

Although it is well established that the growth of solid tumors requires vigorous neovascularization, it has been assumed that leukemias and other hematological malignancies do not depend on angiogenesis. However, the role of angiogenesis in growth and survival of neoplastic cells of the hematopoietic system has recently been recognized, and provides a rationale for novel therapeutic approaches to hematological malignancy. This review summarizes the literature concerning the relationship between angiogenesis and disease progression of several hematological malignancies. It is becoming increasingly evident that agents that interfere with blood vessel formation also block tumor progression, and, accordingly, antiangiogenic therapy has gained much interest as a potential adjunct to conventional therapy of many hematological malignancies. Recent successful applications of antiangiogenic agents that interfere or block the progression of hematological malignancies are evaluated in light of recent demonstrations of potent angiogenic activity of several hematopoietic growth factors. A novel finding regarding the role of angiogenesis in hematological malignancies, which accounts for many clinical observations as well as the apparent independence of these tumors on marrow vascularity, is presented. The information presented in this review will facilitate the design of future clinical trials using antiangiogenic agents for the treatment of hematological malignancies and will provide a basis for the design of experiments undertaken to define the mechanisms involved, mechanisms that may shed new light on the pathology of hematological malignancies.

Topics: Angiogenesis Inhibitors; Animals; Chick Embryo; Clinical Trials as Topic; Disease Progression; Erythropoietin; Humans; Leukemia; Lymphoma; Matrix Metalloproteinases; Neoplasms; Neovascularization, Pathologic; Recombinant Proteins

By definition, idiopathic erythrocytosis (IE) applies to a group of patients characterised by having a measured RCM above their predicted normal range (an absolute erythrocytosis) and following investigation do not have a form of primary or secondary erythrocytosis. Patients with IE are heterogenous. The possibilities include physiological variation, 'early' polycythaemia vera (10-15% develop clear features of PV over a few years), unrecognized congenital erythrocytosis, unrecognized or unrecognizable secondary acquired erythrocytosis or a currently undescribed form of primary or secondary erythrocytosis. Patients are more commonly male with a median age at presentation of 55-60 years. Approximately half of the patients present with vascular occlusive complications. Retrospective evidence indicates that vascular occlusion occurs less frequently when the PCV is controlled at normal levels. Venesection is the treatment of choice to lower the PCV. As a general approach to management, all patients with a PCV above 0.54 should be venesected to a PCV less than 0.45. This target PCV should also apply to patients with lesser degrees of raised PCV who have additional other risk factors for vascular occlusion.

Topics: Aged; Arterial Occlusive Diseases; Bone Marrow; Chlorambucil; Diagnosis, Differential; Endocrine System Diseases; Erythrocyte Volume; Erythroid Precursor Cells; Erythropoietin; Genetic Predisposition to Disease; Humans; Hypoxia; Kidney Diseases; Leukemia; Leukemia, Radiation-Induced; Middle Aged; Phosphorus Radioisotopes; Polycythemia; Polycythemia Vera; Receptors, Erythropoietin; Sequence Deletion; Smoking; Stroke

Topics: Erythropoietin; Humans; Leukemia; Thrombopoietin

Exhaustion and tiredness are frequent symptoms in cancer patients. They are caused by the tumour itself and by application of chemotherapy, surgery, radiation or cytokine treatment. Exhaustion and tiredness are not a consequence of lacking sleep or exaggerated physical or mental labour, but are due to several other factors: Anemia, tumour cachexia, toxicity of chemo- and radiation treatment probably are the most decisive factors for the development of exhaustion and tiredness. As both were taken as inevitable side-effects of cancer and cancer treatment in the past, only little attention has been paid to exhaustion and tiredness and limited research has been done. Among several validated questionnaires measuring quality of life in tumour patients the FACT-An (Functional Assessment of Cancer Treatment--Anemia) and EORTC QLQ-C30 questionnaire are the most well-known for identifying exhaustion and tiredness. Nevertheless, until today there is no mere exhaustion scale exclusively dealing with the problem of exhaustion and tiredness. According to the 10th revision of the International Classification of Diseases (ICD) exhaustion and tiredness are subsumed under the diagnosis of tumour fatigue. In contrast to tumour fatigue, which comprises physical, mental and emotional dimensions, exhaustion and tiredness primarily refer to physical symptoms: Lacking resilience for activities of daily life, day sleepiness and nocturnal insomnia as well as restricted power of concentration are the mainstays of exhaustion and tiredness. However, regarding lacking interests, diminished energy and reduced mental capacity, exhaustion and fatigue partly overlap. From a therapeutic point of view behavioural interventions and drug therapy have successfully been tried. Beside physical exercise and psychostimulants application of Erythropoietin represents an innovative treatment of exhaustion and tiredness.

Topics: Clinical Trials as Topic; Combined Modality Therapy; Erythropoietin; Fatigue; Humans; Leukemia; Neoplasms; Palliative Care; Quality of Life; Recombinant Proteins

This review summarizes selected recent studies of the intracellular signals that allow erythroid cells to survive and proliferate under the control of erythropoietin (EPO) and alteration in signals that contribute to EPO-independent survival and proliferation. The hypothesis explored is that the proliferation and survival signals are distinct and can be separately studied with the proper cell lines and growth factor stimulation. The anti- and pro-apoptotic proteins Bcl-XL and BAD are highly implicated in EPO-dependent survival of erythroid cells. Stat5 activity appears to be upstream of Bcl-XL expression such that pathologic, constitutive activation of Stat5 may be a common event in leukemic cells that become resistant to apoptosis by constitutive expression of Bcl-XL. Other signals apparently also control the expression of Bcl-XL, such as the expression of JunB which seem to be required to suppress Bcl-XL expression when EPO is withdrawn. Apoptosis may also be triggered by inactivation of Bcl-XL by BAD. Dephosphorylation of BAD as a result of withdrawal of survival factors converts prosurvival BAD to proapoptotic BAD. Phosphorylation of BAD at the serine 112 residue seems critical to promoting survival. Constitutive activation of a kinase that phosphorylates BAD serine 112 may, therefore, contribute to resistance to apoptosis in leukemic cells. We describe the resistance of erythroleukemic cells to apoptosis induced by EPO withdrawal apparently caused by constitutive BAD phosphorylation. The resistance to apoptosis in these cells is reversed by treatment with the PI3-kinase inhibitor, LY294002, suggesting that resistance to apoptosis in these cells likely results from constitutive P13-kinase that is an upstream activator of an S-112 BAD kinase. The MAP kinase cascade is apparently active in EPO-dependent and stem cell factor (SCF)-dependent proliferation but not survival. In addition, autocrine tumor necrosis factor-a! (TNF-alpha) may also be a proliferation factor not affecting survival. P13-kinase seems to be required for full EPO-dependent proliferation but is not required for EPO-dependent survival (but it can promote survival when activated).

Topics: Animals; Cell Division; Cell Survival; Erythroid Precursor Cells; Erythropoietin; Humans; Leukemia; Signal Transduction; Stem Cell Factor

Anaemia is a frequent finding in cancer and may be due to different causes. In untreated subjects, the most common type is the so-called anaemia of chronic disease, a condition characterised by excessive release of cytokines such as interleukin-1 and tumour necrosis factor. These peptides both inhibit erythroid marrow proliferation and blunt the normal exponential relationship between haematocrit and serum erythropoietin. Chemotherapy may cause or worsen anaemia in cancer patients. Cisplatin appears to be peculiar in that this drug can blunt erythropoietin production and cause prolonged anaemia. Controlled studies have demonstrated that recombinant human erythropoietin (rHuEPO) can ameliorate anaemia in patients with malignancy and prevent chemotherapy-induced anaemia. However, improvement of anaemia following rHuEPO treatment is seen in only a portion of cancer patients, and significant improvements of quality of life cannot be demonstrated in all responsive patients. Therefore, an important issue remains whom to treat.

Topics: Anemia; Antineoplastic Agents; Clinical Trials as Topic; Erythropoiesis; Erythropoietin; Humans; Leukemia; Lymphoma; Prognosis; Quality of Life; Recombinant Proteins; Treatment Outcome

Anaemia, manifesting as fatigue, dizziness, dyspnoea and anorexia, is common among patients with cancer. A host of factors, such as neoplastic bone marrow infiltration, impaired haematopoiesis, autoimmune haemolysis, impaired endogenous erthropoietin production and treatment with cytotoxic agents contribute to the underlying pathology. Traditionally, blood transfusions have formed the mainstay of therapy for the treatment of cancer-related anaemia. Numerous clinical trials have subsequently confirmed the safety and therapeutic utility of recombinant human erythropoietin (rHuEPO) in anaemic cancer patients, including those with haematological malignancies, such as multiple myeloma and non-Hodgkin's lymphoma. Indeed, well over 50% of unselected patients treated with rHuEPO can be expected to respond with increases in haemoglobin level and/or elimination of transfusion need. In addition, a low baseline serum erythropoietin level can identify those patients with haematological malignancies having a very high likelihood of responding to rHuEPO therapy. These findings, in combination with the possibility of titrating to a lower, maintenance dose, have improved the cost-benefit relationship and thus support the use of rHuEPO as an appropriate alternative to blood transfusions for the management of anaemic patients with lymphoma and myeloma.

Topics: Anemia; Blood Transfusion; Cost-Benefit Analysis; Drug Costs; Erythropoietin; Humans; Leukemia; Lymphoma; Multiple Myeloma; Recombinant Proteins; Treatment Outcome

Anaemia is a common disorder in patients with cancer, occurring in 10-40% of cases, depending upon the tumour type and chemotherapy used. It is present in nearly all patients with leukaemia at some time in the disease and in 50% of patients with lymphoma after chemotherapy. Cancer-related anaemia appears to result from a range of factors including chronic inflammation, blood loss, nutritional deficiencies, haemolysis, bone marrow infiltration by malignant cells, low serum erythropoietin (EPO) levels, and a decrease of bone marrow responsiveness to EPO. The consequences of anaemia, namely fatigue and cardiovascular symptoms, can adversely affect patients' quality of life and may even alter their response to cancer treatment. Moreover, anaemia is often associated with the presence of several adverse prognostic parameters and is also itself a predictor of poor prognosis. Furthermore, anaemia and its symptoms can be exacerbated by cancer treatment. Until recently, blood transfusions have been the mainstay of treatment for cancer-related anaemia, despite the associated risks of transfusion-related reactions and transmission of infection. By increasing haemoglobin levels and haematocrit, treatment with recombinant human erythropoietin (rHuEPO) has been shown to reduce the need for blood transfusion in patients with haematological malignancies. It is recommended that rHuEPO be administered when a patient's haemoglobin level is at risk of falling below 8g/dL, and that treatment is maintained until levels rise above 13g/dL. Consideration of the detrimental effects of anaemia on cancer patients' physical and emotional well-being and therapeutic outcome suggests that rHuEPO therapy has the potential to provide substantial clinical benefits.

Topics: Anemia; Blood Transfusion; Erythropoietin; Humans; Leukemia; Lymphoma; Prognosis; Quality of Life; Recombinant Proteins

Topics: Anemia; Anemia, Sideroblastic; Dose-Response Relationship, Immunologic; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Cell Growth Factors; Hematopoietic Stem Cell Transplantation; Humans; Leukemia; Myelodysplastic Syndromes; Neutropenia

Topics: Anemia, Aplastic; Erythropoietin; Granulocyte Colony-Stimulating Factor; Humans; Leukemia; Myelodysplastic Syndromes

The hemopoietic growth factors are peptide hormones that are known to be responsible for the in vitro and in vivo proliferation of bone marrow progenitor cells into mature differentiated cells. These cytokines have had a major impact on the management of patients with cytopenias and have been extensively used as an adjunct to the management of patients with hematologic malignancies, with or without prior intensive chemotherapy. Other potential uses, being rigorously studied, include the potential mobilization of stem cells as well as recruitment phase-specific cells into the cell cycle, thus providing a more sensitive environment for targeting specific chemotherapeutic agents.

Topics: Acute Disease; Anemia; Anemia, Aplastic; Bone Marrow Transplantation; Colony-Stimulating Factors; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Cell Growth Factors; Humans; Leukemia; Myelodysplastic Syndromes; Neutropenia

Topics: Animals; Colony-Stimulating Factors; Erythropoietin; Hematopoiesis; Humans; Interleukin-5; Leukemia; Mice

Topics: Colony-Stimulating Factors; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Growth Substances; Humans; Interferon Type I; Interferon-gamma; Interferons; Interleukin-3; Leukemia; Leukemia, Hairy Cell; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Myelodysplastic Syndromes; Recombinant Proteins; Thrombocythemia, Essential

Topics: Animals; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Colony-Stimulating Factors; Erythropoietin; Growth Substances; Hematopoietic Stem Cells; Humans; Interleukins; Leukemia; Oncogenes; Receptors, Cell Surface

Topics: Biological Products; Deltaretrovirus; Erythropoietin; Genetic Engineering; Hematologic Diseases; HIV; Humans; Immunoglobulins; Leukemia; Lymphoma; Oncogenes; Receptors, Antigen, T-Cell; Transfection; Translocation, Genetic

Topics: Amino Acid Sequence; Amphibians; Anemia; Animals; Antibodies; Biological Evolution; Bone Marrow; Cell Differentiation; Chick Embryo; DNA; Erythropoiesis; Erythropoietin; Genes; Genetic Variation; Globins; Hematopoietic Stem Cells; Hemoglobins; Humans; Leukemia; Liver; Mammals; Models, Biological; Nucleic Acid Conformation; RNA, Messenger; Transcription, Genetic; Vertebrates

There have been numerous new contributions to the knowledge of foetal haemoglobin over the last few years. It is, therefore, timely to review them together. They throw light on the arrangement on the chromosome of non-alpha chain genes, and on the condition generally known as Hereditary Persistence of Foetal Haemoglobin (HPFH) and have contributed to other aspects of human ontogeny and physiology.

Topics: Adult; Amino Acid Sequence; Anemia, Aplastic; Anemia, Sickle Cell; Child; Erythrocytes; Erythropoietin; Female; Fetal Blood; Fetal Hemoglobin; Genes; Genetic Linkage; Genetic Variation; Genetics, Population; Hemoglobinopathies; Humans; Infant; Infant, Newborn; Leukemia; Oxygen; Pregnancy; Protein Denaturation; Suppression, Genetic; Thalassemia

Topics: Adenocarcinoma; Adrenal Gland Neoplasms; Animals; Brain Neoplasms; Carcinoma; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Cells, Cultured; Cricetinae; Cysts; Erythropoietin; Esophageal Neoplasms; Female; Growth Substances; Haplorhini; Humans; In Vitro Techniques; Kidney Neoplasms; Leiomyoma; Leukemia; Leukemia, Experimental; Liver Neoplasms; Lymphoma; Male; Mice; Neoplasm Metastasis; Neoplasm Transplantation; Pheochromocytoma; Polycythemia; Rats; Sarcoma, Experimental; Skin Neoplasms; Time Factors; Wilms Tumor

Topics: Anabolic Agents; Androgens; Anemia, Aplastic; Bone Marrow Transplantation; Erythropoiesis; Erythropoietin; Hematopoietic Stem Cells; Heme; Hepatitis; Humans; Iron; Leukemia; Transplantation, Homologous; Tuberculosis, Miliary

Topics: Animals; Cell Division; Cortisone; Culture Techniques; Endocrine Glands; Erythropoietin; Glycoproteins; Gonadal Steroid Hormones; Growth Hormone; Growth Inhibitors; Hematopoiesis; Hematopoietic Stem Cells; Hormones; Humans; Leukemia; Leukemia, Erythroblastic, Acute; Leukemia, Experimental; Mice; Neurotransmitter Agents; Radiation Chimera; Remission, Spontaneous; Thrombopoietin; Thymus Gland

Topics: Anemia, Macrocytic; Complement System Proteins; Erythropoietin; Folic Acid; Humans; Leukemia; Vitamin B 12

Topics: Anemia; Anemia, Macrocytic; Blood Platelets; Eosinophilia; Epoetin Alfa; Erythropoietin; Humans; Iron; Leukemia; Polycythemia Vera; Vitamin B 12

Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with prolonged anemia caused by defective erythropoietin (Epo) production. We enrolled 34 recipients of an allogeneic HSCT in three consecutive trials to determine the optimal utilization of recombinant human erythropoietin (rhEpo) therapy in this setting.. In the first trial (n = 7), rhEpo 1400 U/kg/week was given from day 1 until a hemoglobin (Hb) level of 10 g/dL was achieved, for a maximum of 60 days. In the second trial, rhEpo 500 U/kg/week was given to achieve Hb levels of 13 to 14 g/dL in 13 anemic patients with fatigue 56 to 1440 days after transplant. In the third trial, rhEpo was scheduled to start on day 35 in 14 patients at a dose of 500 U/kg/week with the aim of achieving Hb levels of 13 to 14 g/dL.. In trial 1, erythroid recovery to 1% reticulocytes and red blood cell transfusion independence were faster, but the number of transfusions was not reduced compared to 10 controls. Responses were brisk in trial 2, with transfusion independence achieved after a median of 1 week in 12 of 13 patients, and 2-g Hb increments or Hb values of 11, 12, and 13 g/dL after 6, 7, 10, and 10 weeks, respectively. Transfusions were significantly reduced in the first month of rhEpo therapy. In trial 3, transfusion independence was obtained after a median of 1 week in 13 of 14 patients, and 2-g Hb increments or Hb values of 11, 12, and 13 g/dL after 3, 4, 6, and 8 weeks, respectively. Transfusions rates were considerably reduced compared to the previous month in the same patients or compared to controls undergoing peripheral blood or marrow transplant without rhEpo.. Anemia after allogeneic HSCT is exquisitely sensitive to rhEpo. The benefit is minimal when it is given early post-transplant, as used in all trials to date. However, the rate of major response is greater than 90% when rhEpo is started after day 35. These data provide the basis on which to conduct a prospective, randomized, placebo-controlled trial of rhEpo therapy after allogeneic HSCT.

Topics: Adolescent; Adult; Anemia, Aplastic; Bone Marrow Transplantation; Child; Cyclosporine; Drug Administration Schedule; Erythropoietin; Female; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Immunosuppressive Agents; Leukemia; Lymphoma, Non-Hodgkin; Male; Middle Aged; Myelodysplastic Syndromes; Recombinant Proteins; Thrombocytosis; Transplantation, Homologous

Short-term liquid marrow cultures (STLMC) are a potential source for autografting. We have previously shown that the quality of such grafts from transplantation candidates may be improved by hematopoietic cytokine support, especially if purified CD34-positive progenitors are cultured. The aim of this preclinical work was to quantitate ex vivo recovery of myeloid progenitors (colony-forming units-granulocyte/macrophage [CFU-GM]) in STLMC before and after short-term, in vivo treatment with recombinant human granulocyte colony-stimulating factor (rhG-CSF), granulocyte-macrophage colony-stimulating factor (rhGM-CSF), or interleukin-3 (rhIL-3).. Twenty-two sequential patients in marrow remission for hematological malignancies and eligible for autologous marrow transplantation received rhG-CSF or rhGM-CSF for 5 days or rhIL-3 for 10 days before marrow harvest. Marrow samples before and after in vivo priming were studied for CFU-GM in pre- and post-STLMC.. After priming with rhG-CSF, rhGM-CSF, or rhIL-3, the number of isolated light-density cells increased nine-, six-, and two-fold, respectively. The total number of sampled (18 mL marrow) myeloid progenitors preculture (day 7/14 CFU-GM x 10(4) increased significantly from median 0.7/1.1 before to 37.3/26.7 after priming with rhG-CSF (n = 8) and from 5.6/3.4 before to 46.6/44.9 after priming with rhGM-CSF (n = 8) but remained unchanged (3.7/1.5 to 3.6/5.7) after priming with rhIL-3 (n = 6). The number of myeloid progenitors postculture (day 7/14 CFU-GM x 10(4) per 18 mL marrow) in cytokine-supported STLMC significantly increased from median 0.3/0.6 before to 7.0/5.3 after priming with rhG-CSF and from 1.9/1.6 before to 24.4/14.4 after priming with rhGM-CSF but remained unchanged (0.4/0.6 to 0.4/0.2) after priming with rhIL-3. Cytokine-primed and purified CD34+ marrow cells may be expanded in STLMC by a cytokine-driven differentiation into late myeloid progenitors and endstage cells.. In vivo priming of bone marrow cells by hematopoietic cytokines significantly increases the recovery of harvested pre- and postculture myeloid progenitors. During cytokine-supported STLMC, early myeloid progenitors may differentiate into a "very late" progenitor pool with a potential for fast marrow regeneration. The number of such progenitors in cytokine-supported short-term liquid cultures may be sufficient for fast myeloid engraftment and complete peripheral blood or marrow stem-cell support after high-dose chemotherapy.

Topics: Antigens, CD; Antigens, CD34; Bone Marrow; Cell Division; Cytokines; Dose-Response Relationship, Drug; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Stem Cells; Humans; Interleukin-3; Leukemia; Recombinant Proteins; Time Factors; Tumor Cells, Cultured

Patients with haematological malignancies undergoing allogeneic BMT were randomised to treatment with recombinant human erythropoietin (rHuEPO) (n = 25) or placebo (n = 25). rHuEPO was given at 200 U/kg daily for 4 weeks and 200 U/kg twice weekly for a further 4 weeks. The groups were similar regarding several prognostic factors. There were no differences between the two groups regarding time to engraftment, fever, hospitalisation, GVHD, infections, haemorrhages, transplant-related mortality, relapse and survival. However, more patients in the control group had a raised serum creatinine (43% vs 14%; p = 0.04). Red blood cell (RBC) transfusion requirements for the first 2 months after BMT were significantly lower in the rHuEPO group compared with the control group (5 units vs 10; p = 0.04). Time to unsupported Hb > 70 g/l was less in patients treated with rHuEPO (14 days vs 24; p = 0.03). No effect was seen on platelet engraftment or the number of transfused platelet units. Two patients in the control group compared with none in the rHuEPO group became refractory to platelet transfusions. According to the protocol the study drug was reduced (Hb > 100) or discontinued (Hb > 120) for a mean of 3.6 weeks among 11 rHuEPO patients compared with 1.9 weeks among 7 controls (p = 0.02). Seven of the treated patients compared with none of the controls reached Hb > 120 during the study period (p = 0.004). Among the rHuEPO treated patients, EPO-levels were significantly higher than in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Blood Cell Count; Blood Transfusion; Bone Marrow Transplantation; Child; Double-Blind Method; Erythropoiesis; Erythropoietin; Female; Hematologic Diseases; Hemoglobins; Humans; Immunologic Factors; Incidence; Leukemia; Male; Middle Aged; Recombinant Proteins; Reticulocytes; Survival Analysis; Weight Loss

We carried out a pilot study on the use of recombinant human erythropoietin (rHuEPO) in children undergoing allogeneic or mafosfamide-purged autologous BMT for ALL or AML. rHuEPO was administered intravenously at a dose of 75 U/kg/day for 30 days after transplant. Ten rHuEPO-treated patients receiving allogeneic BMT and 10 given autologous BMT were compared with 15 allogeneic and 10 autologous historical controls. Endogenous EPO production was appropriate for the degree of anemia after autologous BMT. In these patients, rHuEPO did not accelerate erythroid repopulation and did not modify transfusion requirements. With allogeneic BMT, erythroid marrow activity increased faster in patients given rHuEPO than in controls and resulted in higher red cell production, the mean reticulocyte count on day +30 being 187 +/- 51 x 10(9)/l in treated patients versus 107 +/- 63 x 10(9)/l in controls (p < 0.01). The total number of RBC units administered was 1.7 +/- 1.3 in the rHuEPO group versus 5.1 +/- 3.0 in the control group (p < 0.001). The total number of platelet transfusions was 4.0 +/- 2.3 for patients given allogeneic BMT and receiving rHuEPO versus 8.4 +/- 6.8 for historical controls (p < 0.05) whereas it was similar in rHuEPO-treated and control autologous BMT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute Disease; Anemia; Blood Transfusion; Bone Marrow Transplantation; Child; Cost-Benefit Analysis; Erythropoiesis; Erythropoietin; Graft Survival; Humans; Immunologic Factors; Leukemia; Recombinant Proteins; Transplantation, Autologous; Transplantation, Homologous; Treatment Outcome

Topics: Bone Marrow Transplantation; Busulfan; Costs and Cost Analysis; Double-Blind Method; Erythrocyte Transfusion; Erythropoietin; Follow-Up Studies; Humans; Leukemia; Lymphoma; Platelet Transfusion; Recombinant Proteins; Time Factors; Transplantation, Homologous; Whole-Body Irradiation

Twenty-eight allogeneic BMT patients (16 with acute leukemia, 12 with chronic myeloid leukemia) were included in a single center, prospective, randomized, controlled trial to assess the value of recombinant human erythropoietin (rh-Epo) in this setting. rh-Epo was administered through a central venous catheter as a single bolus injection (days 0-7: 100 U/kg/d; days 7-30: 150 U/kg/d). No secondary effects to rh-Epo treatment were detected. An earlier appearance of reticulocytes and a diminished need of red blood cells (RBCs) transfusions were observed in patients who were treated with rh-Epo (4 units vs 12 units; p < 0.05). The time to unsupported platelets above 25 x 10(9)/l was less in patients treated with rh-Epo than in control patients (19 days vs 31; p < 0.05), and they received significantly fewer platelet transfusions (36 units vs 138.5; p < 0.05). Our results show that rh-Epo treatment is capable of accelerating the erythroid reconstitution and decreasing the need for RBC transfusions. A beneficial effect on platelet reconstitution is also suggested, but further studies are necessary to confirm this point.

Topics: Adolescent; Adult; Bone Marrow Transplantation; Colony-Forming Units Assay; Combined Modality Therapy; Erythropoiesis; Erythropoietin; Female; Humans; Leukemia; Leukemia, Myeloid, Chronic-Phase; Male; Prospective Studies

Erythropoietin (EPO) suppresses drug-induced apoptosis in EPO-receptor-positive leukemia cells and allows cells to persist after drug treatment by promoting cellular senescence. Importantly a small proportion of senescent cells can re-enter the cell cycle and resume proliferation after drug treatment, resulting in disease recurrence/persistence. Using a single-cell assay to track individual cells that exit a drug-induced senescence-like state, we show that cells exhibit asynchronous exit from a senescent-like state, and display different rates of proliferation. Escaped cells retain sensitivity to drug treatment, but display inter-clonal variability. We also find heterogeneity in gene expression with some of the escaped clones retaining senescence-associated gene expression. Senescent leukemia cells exhibit changes in gene expression that affect metabolism and senescence-associated secretory phenotype (SASP)-related genes. Herein, we generate a senescence gene signature and show that this signature is a prognostic marker of worse overall survival in AML and multiple other cancers. A portion of senescent leukemia cells depend on lysosome activity; chloroquine, an inhibitor of lysosome activity, promotes senolysis of some senescent leukemia cells. Our study indicates that the serious risks associated with the use of erythropoietin-stimulating agents (ESAs) in anemic cancer patients may be attributed to their ability to promote drug-tolerant cancer cells through the senescence program.

Topics: Apoptosis; Cellular Senescence; Erythropoietin; Humans; Leukemia; Neoplasms

This experiment aimed to detect serum erythropoietin (EPO) levels in patients with haematological tumours and to investigate its clinical significance. For this purpose, 110 patients with haematological tumours admitted to our hospital between January 2019 and December 2020 were selected as the study population according to the inclusion and exclusion criteria, and they were included in the case group, and the clinical data of the patients were retrospectively analysed. 90 cases of people without hematological tumors who underwent physical examination during the same period were also included as a control group. The serum EPO levels of the two study groups were compared, and the clinical diagnostic value of EPO was analysed using the subject operating characteristic curve (ROC). Results indicated that of the 110 patients, 56 were leukaemia patients, 24 were multiple myeloma patients and 30 were malignant lymphoma patients. The differences in gender, age, disease history, alcohol consumption and smoking history between the two groups were not significant (P>0.05), while the EPO levels in the control group were significantly lower than those in the case group, with a statistical significant difference of P<0.05. The EPO levels in patients with leukaemia, multiple myeloma and malignant lymphoma were (165.43± 20.46) mU/mL, ( 28.14± 4.51) mU/mL and (86.25±10.33) mU/mL significantly higher than the control group, with a significant difference of P<0.05. Using the absence of haematological tumours as a control, the analysis yielded an area under the ROC curve of 0.995 for EPO diagnosis in patients with leukaemia, a 95% confidence interval of 0.987 to 1.000, a sensitivity of 97.80%, with a sensitivity of 98.2 %; the area under the ROC curve for patients with multiple myeloma was 0.910, with a 95% confidence interval of 0.818 to 1.000, with a sensitivity of 98.90% and specificity of 87.50%; the area under the ROC curve for patients with malignant lymphoma was 0.992, with a 95% confidence interval of 0.978 to 1.000, with a sensitivity of 96.70% and specificity of 96.70%. In conclusion, the serum EPO levels of patients with haematological tumours are significantly higher than those of the normal population, and the detection of serum EPO levels is valuable for the diagnosis of clinical haematological tumours.

Topics: Clinical Relevance; Erythropoietin; Hematologic Neoplasms; Humans; Leukemia; Multiple Myeloma; Retrospective Studies

There are conflicting reports on the adverse effects of erythropoietin (EPO) for the management of cancer-associated anemia. The recognition that erythropoietin receptors (EPORs) are expressed outside the erythroid lineage and concerns that erythropoiesis-stimulating agents (ESAs) may cause tumors to grow and increase the risk of venous thromboembolism have resulted in substantially fewer cancer patients receiving ESA therapy to manage myelosuppressive chemotherapy. In this study, we found that EPO suppresses p53-dependent apoptosis induced by genotoxic (daunorubicin, doxorubicin, and γ-radiation) and non-genotoxic (nutlin-3a) agents and induces a senescence-like state in myeloid leukemia cells. EPO interferes with stress-dependent Mdm2 downregulation and leads to the destabilization of p53 protein. EPO selectively modulates the expression of p53 target genes in response to DNA damage preventing the induction of a number of noncoding RNAs (ncRNAs) previously associated with p53-dependent apoptosis. EPO also enhances the expression of the cyclin-dependent kinase inhibitor p21

Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Survival; Cellular Senescence; Cyclin-Dependent Kinase Inhibitor p27; Daunorubicin; DNA Damage; Doxorubicin; Erythropoietin; Humans; Leukemia; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53

Ginsenoside Rg1 is one effective anticancer and antioxidant constituent of total saponins of Panax ginseng (TSPG), which has been shown to have various pharmacological effects. Our previous study demonstrated that Rg1 had anti-tumor activity in K562 leukemia cells. The aim of this study was designed to investigate whether Rg1 could induce apoptosis in TF-1/Epo cells and further to explore the underlying molecular mechanisms. Here we found that Rg1 could inhibit TF-1/Epo cell proliferation and induce cell apoptosis in vitro in a concentration and time dependent manner. It also suppressed the expression of EpoR on the surface membrane and inhibited JAK2/STAT5 pathway activity. Rg1 induced up-regulation of Bax, cleaved caspase-3 and C-PAPR protein and down-regulation of Bcl-2 and AG490, a JAK2 specific inhibitor, could enhance the effects of Rg1. Our studies showed that EpoR-mediated JAK2/STAT5 signaling played a key role in Rg1-induced apoptosis in TF-1/Epo cells. These results may provide new insights of Rg1 protective roles in the prevention a nd treatment of leukemia.

Topics: Apoptosis; Blotting, Western; Cell Proliferation; Central Nervous System Agents; Erythropoietin; Ginsenosides; Humans; Janus Kinase 2; Leukemia; Real-Time Polymerase Chain Reaction; Receptors, Erythropoietin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; STAT5 Transcription Factor; Tumor Cells, Cultured

Src homology 2 (SH2) domain-containing phosphatase 2 (SHP2), encoded by PTPN11, regulates signaling networks and cell fate in many tissues. Expression of oncogenic PTPN11 in the hematopoietic compartment causes myeloproliferative neoplasm (MPN) in humans and mice. However, the stage-specific effect(s) of mutant Ptpn11 on erythroid development have remained unknown. We found that expression of an activated, leukemogenic Ptpn11 allele, Ptpn11D61Y, specifically in the erythroid lineage causes dyserythropoiesis in mice. Ptpn11D61Y progenitors produce excess cKIT+ CD71+ Ter119- cells and aberrant numbers of cKITl° CD71+ erythroblasts. Mutant erythroblasts show elevated activation of ERK, AKT and STAT3 in response to EPO stimulation, and MEK inhibitor treatment blocks Ptpn11D61Y-evoked erythroid hyperproliferation in vitro. Thus, the expression of oncogenic Ptpn11 causes dyserythropoiesis in a cell-autonomous manner in vivo.

Topics: Alleles; Animals; Antigens, CD; Bone Marrow; Butadienes; Cell Proliferation; Erythroblasts; Erythropoiesis; Erythropoietin; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Leukemic; Hematopoietic Stem Cells; Leukemia; Mice; Nitriles; Protein Kinase Inhibitors; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-kit; Receptors, Transferrin; Signal Transduction; STAT3 Transcription Factor

The transcription factor Wilms' tumor gene 1 (WT1) is highly expressed in the majority of leukemias, suggesting a role in leukemogenesis. Acquired WT1 mutations are reported as an independent predictor of poor clinical outcome, and mutations resulting in deletion of the entire DNA-binding zinc-finger domain (WT1delZ), is the most common type. The aim of this study was to study cellular effects of WT1(delZ) that may contribute to an oncogenic phenotype. We found that expression of WT1(delZ) supported proliferation of human hematopoietic CD34(+) progenitor cells. Moreover, WT1(delZ) transduced cells expressed erythroid markers, including raised levels of STAT5, independently of addition of erythropoietin. At the global gene expression level, WT1(delZ) caused upregulation of genes related to cell division and genes associated with erythroid maturation, in the absence of added erythropoietin. Our results indicate that WT1(delZ) promotes cell proliferation and expansion of progenitor cells, consistent with a possible role in leukemogenesis.

Topics: Antigens, CD34; Cell Culture Techniques; Cell Proliferation; Colony-Forming Units Assay; Erythropoietin; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Hematopoietic Stem Cells; Hemoglobin A; Humans; Leukemia; Mutant Proteins; STAT5 Transcription Factor; Transduction, Genetic; WT1 Proteins

Hepcidin plays a central role in iron homeostasis, which is regulated by iron stores, the rate of erythropoiesis, inflammation, and hypoxia. Aberrant expression of hepcidin was found in many diseases, however, there is scant information on hepcidin expression in acute leukemia (AL).. 32 patients with AL which diagnosis according to FAB criteria were studied. Serum hepcidin levels, erythropoietin (EPO), interleukin-6 (IL-6), hematological parameters, intracellular and extracellular iron store were evaluated.. Hepcidin was elevated significantly with increased iron storage in patients at onset of AL when erythropoiesis was depressed by blast cells, then decreased significantly with AL remission, while soluble transferrin receptor (sTfR) concentration was elevated. Negative correlations were found between serum hepcidin and erythropoietic markers including RBC, Hb, Ret and sTfR. Positive correlations were shown between hepcidin and ferritin, between hepcidin and ratio of sideroblasts, as well as between hepcidin and IL-6.. Hepcidin production was regulated by iron stores, inflammation and erythropoietic activity in AL patients. Erythropoietic activity may play the main role among the regulators of hepcidin expresssion.

Topics: Adult; Antimicrobial Cationic Peptides; Erythropoiesis; Erythropoietin; Female; Ferritins; Hepcidins; Humans; Interleukin-6; Leukemia; Male; Middle Aged; Receptors, Transferrin; Statistics as Topic; Transferrin; Young Adult

To study levels of hepsidine (Hp), hypoxia-inducible factor-1alpha (HIF-1alpha), erythropoietin (EP) and ferritin in patients with acute leukemia (AL), effects of protein fractions of homogenate of blastic cells (BC) on regulatory proteins studied.. Depending on leukocyte count in the onset of AL, 70 patients with first ever diagnosed AL were divided into two groups: group 1 - 17 patients with leukocyte count > 30 x 10(9)/l, group 2 - 53 patients with leukocyte count < 30 x 10(9)/l. Serum and leukocyte parameters were studied before treatment, during the treatment with cytostatic drugs, in the course of myelotoxic agranulocytosis (MTA), after normalization of hemograms. EP was detected with enzyme immunoassay, serum and leukocyte ferritin - with radioimmunoassay; HIF-1alpha, Hp - sandwich enzyme immunoassay using monospecific antisera and monoclonal antibodies against relevant antigens. Leukocytes were isolated in ficol and verografin solutions density gradient. Chromatographic division of the protein fractions in 3 patients with leukocytosis in AL onset and leukocytes of 3 donors was made by the method of preparative isoelectrofocusing of BC and leukocytes on LKB colon (Sweden). Effects of these fractions were studied on 11 plasma samples from hematological patients and 4 plasma samples from patients with normal hemopoiesis.. Leukocytosis patients with initial AL have serum ferritin, Hp and HIF-1alpha levels about 2-5 times lower than patients without leukocytosis. Cytostatic treatment raises an HIF-1alpha level in BC about 15-fold (85.8 +/- 24.5 pg/ml), in the study group - 3-fold (15.2 +/- 3.3 pg/ml). The highest EP levels were seen in MTA. It is detected that protein fractions isolated from leukocytes of patients with leukocytosis in the disease onset raise HIF-1alpha content irrespective of HIF-1alpha presence in the fraction. Patients free of hematological diseases have no changes of the above proteins.. Great difficulties exist in ferritin and Hp levels between AL patients with leukocytosis in the onset of the disease and without of leukocytosis. The study of leukocytes suggests that tumor cells of such patients contain compounds which can regulate production of HIF-1alpha, Hp and ferritin.

Topics: Acute Disease; Erythropoietin; Ferritins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Iron; Leukemia; Leukocytosis; Radioimmunoassay

Overexpression of the transcription factor Spi-1/PU.1 by transgenesis in mice induces a maturation arrest at the proerythroblastic stage of differentiation. We have previously isolated a panel of spi-1 transgenic erythroleukemic cell lines that proliferated in the presence of either erythropoietin (Epo) or stem cell factor (SCF). Using these cell lines, we observed that EpoR stimulation by Epo down-regulated expression of the SCF receptor Kit and induced expression of the Src kinase Lyn. Furthermore, enforced expression of Lyn in the cell lines increased cell proliferation in response to Epo, but reduced cell growth in response to SCF in accordance with Lyn ability to down-regulate Kit expression. Together, the data suggest that Epo-R/Lyn signaling pathway is essential for extinction of SCF signaling leading the proerythroblast to strict Epo dependency. These results highlight a new role for Lyn as an effector of EpoR in controlling Kit expression. They suggest that Lyn may play a central role in during erythroid differentiation at the switch between proliferation and maturation.

Topics: Animals; Cell Line; Cell Proliferation; Cytokines; Down-Regulation; Erythroblasts; Erythropoietin; Leukemia; Mice; Mutant Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-kit; Receptors, Erythropoietin; src-Family Kinases; STAT5 Transcription Factor; Trans-Activators

To estimate the levels of hepsidine, HIF-1alpha, erythropoietin, other proteins of iron metabolism; to characterize dysregulation of metabolic processes in leukogenesis.. Thirty eight patients with newly diagnosed acute leukemia (AL) were divided into three groups by anemia severity: group 1 (Hb > 90 g/l), group 2 (Hb 90-70 g/l), group 3 (Hb < 70 g/l). Erythropoietin concentration was measured with enzyme immunoassay, serum ferritin (SF)--by radioimmunoassay; HIF-1alpha, hepsidine--by sandvich enzyme immunoassay with use of monospecific antisera and monoclonal antibodies against relevant antigens.. In AL patients SF before treatment was 10 times higher than in healthy subjects, administration of cytostatics elevated this concentration even more. Hepsidine and HIF-1alpha are also elevated. Treatment reduces hepsidine level twice in all the groups. This may be due to reduction of the tumor mass. Erythropoietin was 20-35 times higher in all the patients, especially in myelotoxic agranulocytosis (up to 1000 mU/ml) with reduction after recovery of hemopoiesis (in some patients to normal values 20-30 mU/ml). Hepsidine and HIF-1alpha concentrations were also maximal in myelotoxic agranulocytosis (20-28 pg/ml). After recovery of hemopoiesis these values fell to initial values 7-9 pg/ ml). Transfusion of donor erythrocytic mass normalized HIF-1alpha concentration and decreased that of hepsidine. Its elevation and high HIF-1alpha were observed after the transfusion in 17% patients.. Disorders in regulatory mechanisms in AL patients throughout the observation confirm the role of the proteins studied in homeostasis. Changes in HIF-1alpha and hepsidine concentrations can be used as indicators of transfusion efficacy.

Topics: Antimicrobial Cationic Peptides; Erythrocyte Transfusion; Erythropoietin; Hemoglobins; Hepcidins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Iron; Leukemia; Predictive Value of Tests

To detect serum erythropoietin (EPO) levels in patients with acute leukemia (AL) and iron deficient anemia (IDA) with moderate or severe anemia and explore the mechanism of anemia in these patients.. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of EPO in 59 patients with AL, among whom 15 had complete remission without anemia and 44 had moderate or severe anemia (including 12 receiving the initial treatment, 13 with complete remission and concurrent anemia, and 19 with bone marrow suppression). Serum EPO was also detected in 15 IDA patients and 12 healthy individuals.. The IDA patients and healthy individuals had similar serum EPO levels (P>0.05), and by comparison, the EPO levels were significantly increased in AL patients upon the initial treatment, those with bone marrow suppression and those with complete remission and anemia, but comparable between the latter 3 groups (P>0.05). Among the patients with complete remission, the EPO levels were significantly higher in anemic patients than in those without anemia (P<0.05), and the latter patients had similar EPO levels with the healthy individuals (P>0.05). In both AL and IDA patients with moderate or severe anemia, the serum EPO level was inversely correlated to the level of hemoglobin (r=-0.697 and -0.970, respectively, P<0.05).. AL patients with anemia have significantly higher serum EPO levels than healthy individuals. In AL and IDA patients with moderate or severe anemia, EPO levels are inversely correlated to the level of hemoglobin, suggesting the integrity of the EPO synthesis mechanism in AL patients. Serum EPO level is also associated with bone marrow function in addition to hypoxia and hemoglobin levels, and hematopoiesis deficit in the early stage may be the main cause of anemia.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Anemia; Erythropoietin; Female; Humans; Leukemia; Male; Middle Aged; Young Adult

Previous prognostic studies in primary myelofibrosis have focused on risk factors for overall survival and have resulted in the establishment of several prognostic scoring systems. However, to the authors' knowledge, information regarding risk factors for leukemic transformation in primary myelofibrosis is limited.. The current retrospective study examined clinical variables at the time of diagnosis and specific treatment modalities for their effect on leukemic transformation in 311 patients with primary myelofibrosis who were seen at the Mayo Clinic.. Univariate analysis of parameters at the time of diagnosis revealed a significant association between inferior leukemia-free survival and a peripheral blood blast percentage>or=3 (P<.0001), a platelet count<100x10(9)/L (P=.004), a monocyte count>or=1x10(9)/L (P=.02), the presence of hypercatabolic symptoms (P=.03), a low hemoglobin level (P=.04), and a high leukocyte count (P=.04). The first 2 parameters were found to maintain their statistical significance during multivariate analysis. Neither leukemia-free nor overall survival was found to be affected by the presence of <3% peripheral blood blasts or JAK2V617F mutation. The evaluation of treatment effect on leukemic transformation unexpectedly revealed a significant and independent association with previous therapy with either erythropoiesis-stimulating agents (P=.004) or danazol (P=.007), even when the aforementioned prognostic indicators at the time of diagnosis were added as covariates to the multivariate model. In contrast, leukemia-free survival was not found to be affected by a treatment history with hydroxyurea, thalidomide, or other drugs.. A peripheral blood blast percentage>or=3 and/or a platelet count<100x10(9)/L at the time of diagnosis were found to be strong and independent predictors of leukemic transformation in patients with primary myelofibrosis. The unexpected association between leukemic transformation and a history of treatment with erythropoiesis-stimulating agents or danazol requires validation by prospective studies.

Topics: Cell Transformation, Neoplastic; Danazol; Erythropoietin; Female; Humans; Leukemia; Male; Middle Aged; Primary Myelofibrosis; Risk Factors

FKHRL1 is one of the human homologues of DAF-16, which is concerned with longevity in Caenorhabditis elegans. Previously, we demonstrated that FKHRL1 functions downstream of Akt in erythropoietin (EPO) signaling and that it is directly phosphorylated by activated Akt. Because phosphorylated FKHRL1 loses its transcriptional activity and translocates into the cytoplasm, FKHRL1 appears to be nonfunctional in the presence of EPO. Conversely, EPO deprivation leads to FKHRL1 dephosphorylation and its translocation into the nucleus, suggesting that FKHRL1 becomes active as a transcription factor in the absence of EPO. On the basis of these findings, we hypothesized, by analogy with C elegans, that erythroid cells possess self-defense machinery against life-threatening surroundings. We prepared a dominant-negative mutant of FKHRL1 (FKHRL1-DN) lacking the transactivation domain and prepared FKHRL1 small interfering RNA (siRNA), and we used constructs to transfect a human EPO-dependent cell line, UT-7/EPO. In the parental cells, 24-hour EPO deprivation induced transient cell cycle arrest without apoptosis. On the other hand, stable transfectants expressing FKHRL1-DN or FKHRL1 siRNA underwent rapid apoptosis after EPO deprivation in the UT-7/EPO cells. In conclusion, FKHRL1 activation plays an important role in the extension of survival of erythroid cells after EPO deprivation. This phenomenon appears to correspond to dauer formation in C elegans. Thus, the mechanism of lifespan extension may be broadly conserved from C elegans to humans.

Topics: Apoptosis; Cell Line; Cell Nucleus; Cytoplasm; Erythroid Cells; Erythropoietin; Forkhead Box Protein O3; Forkhead Transcription Factors; Gene Expression Regulation; Humans; Leukemia; Protein Transport; RNA, Small Interfering

Hematopoietic cytokines play crucial roles in regulation of cell cycle progression and apoptosis of hematopoietic cells. However, the effects of cytokines on cellular responses to chemotherapeutic agents and the mechanisms involved have remained elusive. Here we report that erythropoietin or IL-3 promotes G2/M arrest and prevents apoptosis induced by the topoisomerase II inhibitor etoposide in murine hematopoietic 32D cells and human leukemic UT7 cells. Erythropoietin or IL-3 significantly enhanced etoposide-induced activation-specific phosphorylation of Chk1, a checkpoint kinase that inhibits Cdc2 activation by Cdc25 phosphatases, and led to the inhibition of Cdc2 kinase activity with the persistent inhibitory phosphorylation on Tyr15. The inhibitory Cdc2 phosphorylation and G2/M block by etoposide were enhanced or inhibited by overexpression of Chk1 or by the specific Chk1 inhibitor SB218078, respectively. The G2/M arrest induced by etoposide was also enhanced or inhibited by expression of a constitutively activated or dominant-negative Akt mutant, respectively. Furthermore, SB216763 or LiCl, a specific inhibitor for the GSK3 kinase inhibited by Akt, enhanced the Chk1 phosphorylation and G2/M arrest by etoposide. These results indicate that hematopoietic cytokines protect etoposide-treated cells from DNA damage-induced apoptosis by promoting, through the PI3K/Akt/GSK3 signaling pathway, G2/M checkpoint that is dependent on Chk1-mediated inhibition of Cdc2.

Topics: Animals; Apoptosis; Cell Cycle; Cell Division; Cell Line; Cell Line, Tumor; Checkpoint Kinase 1; Cytokines; Erythropoietin; Etoposide; Flow Cytometry; G2 Phase; Glycogen Synthase Kinase 3; Humans; Interleukin-3; Leukemia; Mice; Phosphorylation; Phosphotyrosine; Protein Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt

Activation of the phosphoinositide 3 kinase (PI3K)/Akt signalling pathway has been linked with resistance to chemotherapeutic drugs, and its downregulation, by means of PI3K inhibitors, lowers resistance to various types of therapy in tumour cell lines. Recently, it has been reported that deguelin, a naturally occurring rotenoid, is a powerful inhibitor of PI3K. We investigated whether or not deguelin could enhance the sensitivity to chemotherapeutic drugs of human U937 leukaemia cells and acute myeloid leukaemia (AML) blasts with an activated PI3K/Akt network. Deguelin (10 nmol/l) induced S phase arrest with interference of progression to G2/M, and at 100 nmol/l significantly increased apoptotic cell death of U937. At 10-100 nmol/l concentrations, deguelin downregulated Akt phosphorylation of leukaemia cells and markedly increased sensitivity of U937 cells to etoposide or cytarabine. A 10 nmol/l concentration of deguelin did not negatively affect the survival rate of human cord blood CD34+ cells, whereas it increased sensitivity of AML blasts to cytarabine. Deguelin was less toxic than wortmannin on erythropoietin- and stem cell factor-induced erythropoiesis from CD34+ progenitor cells. Overall, our results indicate that deguelin might be used in the future for increasing sensitivity to therapeutic treatments of leukaemia cells with an active PI3K/Akt signalling network.

Topics: Acute Disease; Antigens, CD34; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cells, Cultured; Cytarabine; Drug Resistance, Neoplasm; Erythropoietin; Etoposide; HL-60 Cells; Humans; Leukemia; Leukemia, Myeloid; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Rotenone; Signal Transduction; Stem Cell Factor; Stem Cells

TEL/ETV6 accelerates erythroid differentiation in the murine erythroleukemia cell line. To clarify the effects of TEL on megakaryocytic maturation as well as erythroid differentiation, we chose the human leukemia cell line UT-7/GM that differentiates into the erythroid and megakaryocytic lineages by treatment with erythropoietin and thrombopoietin, respectively. Upon erythropoietin exposure, overexpressed TEL stimulated hemoglobin synthesis and accumulation of the erythroid differentiation-specific transcripts such as gamma-globin, delta-aminolevulinic acid synthase-erythroid, and erythropoietin receptor. Moreover, the glycophorin A(+)/glycoprotein IIb(-) fraction appeared more rapidly in the TEL-overexpressing cells. Interestingly, overexpression of TEL was associated with lower levels of the megakaryocytic maturation-specific glycoprotein IIb and platelet factor 4 transcripts under the treatment with thrombopoietin. Consistently, the glycophorin A(-)/glycoprotein IIb(+) fraction increased more slowly in the TEL-overexpressing cells. Finally, expression of endogenous TEL proteins in UT-7/GM cells was down-regulated following erythropoietin and thrombopoietin exposure. All these data suggest that TEL may decide the fate of human erythrocyte/megakaryocyte common progenitors to differentiate towards the erythroid lineage and against the megakaryocytic lineage.

Topics: Cell Differentiation; DNA-Binding Proteins; Down-Regulation; Erythrocytes; Erythropoietin; ETS Translocation Variant 6 Protein; Humans; Leukemia; Megakaryocytes; Nuclear Proteins; Phosphoproteins; Proto-Oncogene Proteins c-ets; Repressor Proteins; Thrombopoietin; Tumor Cells, Cultured

We describe a case of natural killer (NK) cell leukemia with acute presentation, systemic symptoms and hepatosplenomegaly. The uniform and aberrant phenotype of NK cells with infiltration of bone marrow and spleen was in keeping with a malignant diagnosis. Aggressive presentation was demonstrated by marked constitutional symptoms and significant tumor burden (liver, spleen, blood, bone marrow). The subsequent clinical course has been indolent, but this may have been influenced by treatment. Treatment consisted sequentially of splenectomy, intravenous pentostatin and the combination of cyclosporine A and recombinant human erythropoietin and has resulted in survival of over 48 months. We discuss the difficulties in the diagnosis of this condition, explore possible causes of cytopenia(s), and highlight the role of immunosuppression in controlling disease manifestations in large granular lymphocyte proliferative disorders.

Topics: Antineoplastic Combined Chemotherapy Protocols; Combined Modality Therapy; Cyclosporine; Erythropoietin; Flow Cytometry; Humans; Immunophenotyping; Killer Cells, Natural; Leukemia; Male; Middle Aged; Pentostatin; Recombinant Proteins; Splenectomy

To investigate the effect of immobilized cytokine, erythropoietin (Epo) was immobilized on a culture plate and the Epo-dependent human leukemia cell line UT-7/Epo then was cultured upon the plate. A photo-reactive gelatin was mixed with Epo and the mixture was cast on a plate. The plate was then irradiated with ultraviolet light in the presence or absence of a photo-mask. After washing with water, a micropatterned or unpatterned surface was formed. A leukemia cell line dependent on Epo, UT-7/Epo, was cultured on the sample plate. On the micropatterned surface, apoptosis of cells was induced on the surface without Epo, but was not observed on the Epo-immobilized surface. This result demonstrated that Epo stimulated the cells even after immobilization. Although the activity of immobilized Epo was low, the activity was slightly higher than that achieved by soluble Epo at higher concentration. In addition, the immobilized Epo could be repeatedly used for culture of UT-7/Epo cell. The present study provided a convenient immobilization method and indicated that immobilization of cytokines will be useful for creating an artificial cell culture device.

Topics: Adsorption; Biocompatible Materials; Cell Adhesion; Cell Culture Techniques; Cell Division; Cell Line, Tumor; Erythropoietin; Gelatin; Humans; Leukemia; Materials Testing; Photochemistry; Protein Binding; Tissue Engineering; Ultraviolet Rays

It is now well established that after conventional allogeneic hematopoietic stem-cell transplantation (HSCT), erythropoietic recovery is impaired because erythropoietin (Epo) production remains inadequate for prolonged periods of time. However, erythropoietic reconstitution after nonmyeloablative SCT (NMSCT) has never been characterized.. Twelve patients received a nonmyeloablative conditioning regimen consisting of 2 Gy total body irradiation (TBI) alone (n=6), 2 Gy TBI and fludarabine (n=3), or cyclophosphamide and fludarabine (n=3), followed by transplantation of allogeneic peripheral blood stem cells. Graft-versus-host-disease (GvHD) prophylaxis was carried out with mycophenolate mofetil (from day -1 to day 28) plus cyclosporine (from day -1 to day 120 or longer in case of chronic GvHD). Erythropoiesis was quantitated by soluble transferrin receptor (sTfR) levels, and the adequacy of Epo production was evaluated by the observed-to-predicted Epo ratio (O/P Epo).. Mean sTfR levels decreased following the conditioning regimen but remained well within the normal range throughout the posttransplant period. The O/P Epo ratio presented an initial surge quite similar to that observed after conventional conditioning. Thereafter, the O/P Epo ratio normalized rapidly, and Epo levels remained adequate during the whole observation period.. Contrarily to what is observed after myeloablative transplant, Epo levels remained adequate after NMSCT, resulting in normal erythropoiesis. These results suggest that the administration of erythropoietin therapy (rHuEpo) could be less effective after NMSCT than after conventional allogeneic transplant.

Topics: Adult; Cyclosporine; Erythropoiesis; Erythropoietin; Female; Graft Rejection; Hematopoietic Stem Cell Transplantation; Humans; Immunosuppressive Agents; Leukemia; Lymphoma; Male; Middle Aged; Mycophenolic Acid; Receptors, Transferrin; Recombinant Proteins; Transplantation Conditioning; Transplantation, Homologous

Signal transducers and activators of transcription (Stat) proteins play important roles in the regulation of hematopoiesis as downstream molecules of cytokine signal transduction. It was previously demonstrated that erythropoietin (EPO), a major regulator of erythropoiesis, activates 3 different Stat members, Stat1, Stat3, and Stat5, in a human EPO-dependent cell line, UT-7/EPO. To clarify the mechanism by which EPO activates Stat1 and Stat3 via the EPO receptor (EPOR), a series of chimeric receptors was constructed bearing the extracellular domain of the granulocyte colony-stimulating factor receptor linked to the transmembrane domain of EPOR and the full length or several mutants of the cytoplasmic domain of EPOR, and these chimeric receptor complementary DNAs were introduced into UT-7/EPO cells. Tyr432 on human EPOR was important for activation of Stat1 and Stat3 and c-myc gene induction. In addition, Jak2 and Fes tyrosine kinases were involved in EPO-induced activation of Stat1 and Stat3. These results indicate that Stat1 and Stat3 are activated by EPO via distinct mechanisms from Stat5.

Topics: Cell Division; DNA-Binding Proteins; Enzyme Activation; Erythropoiesis; Erythropoietin; Fusion Proteins, gag-onc; Granulocyte Colony-Stimulating Factor; Humans; Janus Kinase 2; Leukemia; Mutagenesis, Site-Directed; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-myc; Receptors, Erythropoietin; Receptors, Granulocyte Colony-Stimulating Factor; Recombinant Fusion Proteins; STAT1 Transcription Factor; STAT3 Transcription Factor; Structure-Activity Relationship; Trans-Activators; Transfection; Tumor Cells, Cultured; Tyrosine

The mitogen-activated protein (MAP) kinase cascade is a key regulator of mammalian cell proliferation and differentiation. In this study, we examined the roles of 2 members of the MAP kinase family, extracellular signal-regulated kinase 1 (Erk1) and Erk2, in erythropoietin (EPO)-induced erythroid differentiation and thrombopoietin (TPO)-induced megakaryocytic differentiation. UT-7/GM was used as a model system because this cell line is an erythroid/megakaryocytic bipotent cell line that can be induced to differentiate into the erythroid and megakaryocytic lineages by EPO and TPO, respectively. The kinetics of activation of Erk1 and Erk2 were examined during erythroid and megakaryocytic differentiation of UT-7/GM cells. EPO induced a transient activation of these kinases, peaking after 1 minute of stimulation and then declining quickly almost to the basal level. In contrast, TPO-induced activation of the kinases peaked at 10 minutes and persisted for up to 60 minutes, similar to the activation by granulocyte-macrophage colony-stimulating factor. The percentage of EPO-induced hemoglobin-positive cells was elevated by the addition of PD98059, a specific inhibitor of MEK1 (MAP kinase/ERK kinase 1). In contrast, PD98059 clearly reduced the amount of glycoprotein IIb/IIIa antigens induced by TPO on UT-7/GM cells. Thus, inactivation of Erk1 and Erk2 kinases promoted EPO-induced erythroid differentiation and suppressed TPO-induced megakaryocytic differentiation of UT-7/GM cells. In conclusion, the activation of Erk1 and Erk2 kinases may be a critical event in the determination of cell fate and the differentiation processes of the erythroid and megakaryocytic lineages.

Topics: Cell Differentiation; Cell Lineage; Dose-Response Relationship, Drug; Enzyme Inhibitors; Erythroid Precursor Cells; Erythropoietin; Humans; Leukemia; MAP Kinase Kinase 1; Megakaryocytes; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Protein Serine-Threonine Kinases; Thrombopoietin; Tumor Cells, Cultured

Myelodysplastic syndrome (MDS) is characterised by ineffective erythropoiesis and poor progenitor response to erythropoietin (Epo). The aim of this study was to determine the role of the Epo-R mediated signalling in the rise of MDS and whether alteration of signalling pathways contribute to the leukeamogenesis from MDS to acute leukaemia. We analysed Epo and GM-CSF induced ERK1/2 activation, c-Fos expression, STAT-5 and AP-1 DNA binding activities in mononuclear cells of umbilical cord blood (UCBMNC), normal marrow (NBMMNC) or marrow with MDS, AML with prior MDS and de novo AML. In UCBMNC and NBMMNC, Epo and GM-CSF induced the activation of STAT-5 DNA binding and ERK 1/2 activation (n = 6). In contrast, in MDS RA, both signalling pathways were activated only by GM-CSF but not by Epo (n = 7). In acute leukaemia, elevated basal activity of STAT-5 DNA binding appeared in 8/8 cases, which was independent of Epo or GM-CSF treatment. In normal and MDS samples, c-Fos and Egr-1 proteins were not detectable and the expression levels were not increased by Epo or GM-CSF treatment. In contrast, we found an elevated level of c-Fos expression in 5/8 acute leukemia cases, which was not further increased in the presence of Epo or GM-CSF. The elevated c-Fos expression was accompanied by an extremely high blast number in 5/5 cases. These results suggest that impaired ERK/MAPK activation, similarly to impaired STAT-5 activation in Epo-R signalling, may be responsible for the apoptotic process and the block of maturation in MDS RA. The results also suggest that the appearance of the constitutively activated STAT-5 DNA binding and c-Fos expression may be used as a predictor of the blastic transformation.

Topics: Acute Disease; Adolescent; Adult; Aged; Bone Marrow Cells; Case-Control Studies; DNA-Binding Proteins; Enzyme Activation; Erythropoietin; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Leukemia; Male; Middle Aged; Milk Proteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Myelodysplastic Syndromes; Phenotype; Proto-Oncogene Proteins c-fos; Signal Transduction; STAT5 Transcription Factor; Trans-Activators

To better understand the role of retinoids in myelopoiesis, expression of the retinoid receptor genes (retinoic acid receptors [RARs] and retinoid X receptors [RXRs]) were examined during differentiation of factor-dependent cell-Paterson (FDCP)-mixA4 murine progenitor cells. The major receptor expressed in undifferentiated A4 cells was RARalpha (primarily the RARalpha1 isoform). Following induction of myelomonocytic differentiation with granulocyte and granulocyte-macrophage colony-stimulating factors, a dramatic increase in RARalpha expression (particularly the RARalpha2 isoform) was seen. In contrast, expression of both RARalpha isoforms was rapidly extinguished upon induction of erythroid differentiation with erythropoeitin (EPO). A modest induction of RXRalpha expression was seen, particularly during differentiation in the myelomonocytic lineage. Low expression levels of RARgamma2 and RXRbeta remained unchanged, irrespective of differentiation pathway. Consistent with the gene expression patterns, RARalpha agonists and antagonists stimulated myelomonocytic and erythroid differentiation of FDCP-mixA4 cells, respectively. Taken together, these results suggest that erythropoiesis and granulopoiesis require diminished and enhanced RARalpha activities, respectively, which at physiological all-trans-retinoic acid (RA) concentrations may be accomplished by reciprocal effects of EPO and myelomonocytic growth factors on its expression. This hypothesis is corroborated by data showing that RA, which positively regulates RARalpha2 expression, can exert inhibitory effects on erythroid differentiation.

Topics: Bone Marrow; Bone Marrow Cells; Cell Differentiation; Cells, Cultured; DNA Primers; Erythropoietin; Gene Expression Regulation; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Stem Cells; HL-60 Cells; Humans; Leukemia; Models, Biological; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Reverse Transcriptase Polymerase Chain Reaction; Tretinoin; Tumor Cells, Cultured

To investigate the expression of erythropoietin receptor (EpoR) in leukemic cell lines and to clarify the mechanism of proliferative signal transmission in the leukemic cell line KOCL-33 mediated by EpoR.. Biotinylated Epo and flow cytometry were used for EpoR expression, (3)H-TdR incorporation for cell proliferation, immunoprecipitation and Western blot analysis for the tyrosine phosphorylation of signal transmission proteins.. (1) All the cell lines tested expressed EpoR except for T-lymphoid cell lines. The positivity rates ranged from 18% to 99% with an average of 52%, and was no difference among T, B and non-lymphoid cells. (2) The cell proliferation was significantly enhanced in response to Epo in 7 of 9 cell lines tested. The stimulating effects of Epo did not correlate with the densities of EpoR expressed on the cells. (3) The proliferation of KOCL-33 cells was significantly enhanced in response to Epo. Dimerization and tyrosine phosphorylation of EpoR and tyrosine phosphorylation of JAK2 occurred in 1 min and tyrosine phosphorylation of STAT5 in 5 minutes after Epo stimulation.. (1) There was EpoR expression in leukemic cell lines. (2) The cell proliferation could be stimulated by Epo in some leukemic cell lines. The stimulating effect of Epo did not correlate with the densities of EpoR expressed on the cells. (3) Dimerization and tyrosine phosphorylation of EpoR occurred, and JAK2, STAT5 involved in the proliferative signal transmission in KOCL-33 cells mediated by EpoR.

Topics: Cell Division; Dimerization; DNA-Binding Proteins; Erythropoietin; Humans; Janus Kinase 2; Leukemia; Milk Proteins; Phosphorylation; Precipitin Tests; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Receptors, Erythropoietin; Signal Transduction; STAT5 Transcription Factor; Trans-Activators; Tyrosine

Five tyrosine-phosphorylated proteins with molecular masses of 180, 145, 116, 100, and 70 kD are associated with phosphatidylinositol 3-kinase (PI 3-kinase) in erythropoietin (Epo)-stimulated UT-7 cells. The 180- and 70-kD proteins have been previously shown to be IRS2 and the Epo receptor. In this report, we show that the 116-kD protein is the IRS2-related molecular adapter, GAB1. Indeed, Epo induced the transient tyrosine phosphorylation of GAB1 in UT-7 cells. Both kinetics and Epo dose-response experiments showed that GAB1 tyrosine phosphorylation was a direct consequence of Epo receptor activation. After tyrosine phosphorylation, GAB1 associated with the PI 3-kinase, the phosphotyrosine phosphatase SHP2, the phosphatidylinositol 3,4,5 trisphosphate 5-phosphatase SHIP, and the molecular adapter SHC. GAB1 was also associated with the molecular adapter GRB2 in unstimulated cells, and this association dramatically increased after Epo stimulation. Thus, GAB1 could be a scaffold protein able to couple the Epo receptor activation with the stimulation of several intracellular signaling pathways. Epo-induced tyrosine phosphorylation of GAB1 was also observed in normal human erythroid progenitors isolated from cord blood. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and thrombopoietin (TPO) also induced the tyrosine phosphorylation of GAB1 in UT-7 cells, indicating that this molecule participates in the signal transduction of several cytokine receptors.

Topics: Adaptor Proteins, Signal Transducing; Adaptor Proteins, Vesicular Transport; Amino Acid Sequence; Erythropoietin; Fetal Blood; Hematopoietic Stem Cells; Humans; Intracellular Signaling Peptides and Proteins; Leukemia; Molecular Weight; Phosphatidylinositol 3-Kinases; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; Phosphoproteins; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotyrosine; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Protein Tyrosine Phosphatases; Proteins; Recombinant Proteins; SH2 Domain-Containing Protein Tyrosine Phosphatases; Shc Signaling Adaptor Proteins; Src Homology 2 Domain-Containing, Transforming Protein 1; src Homology Domains; Transfection; Tumor Cells, Cultured

Bone marrow depression is a common feature in hematological malignancies or other bone marrow-involving cancers. The mechanism of this hemopoietic suppression resulting in pancytopenia and especially anemia has not been elucidated. Gangliosides can be shed by cancer cells. Therefore, we investigated the effects of exogenously added gangliosides on erythropoiesis in a human and murine in vitro system. A dose-dependent inhibition of murine colony-forming-unit-erythroid (CFU-E) and burst-forming-unit-erythroid (BFU-E) colony growth was observed. Furthermore the maturation of BFU-Es into CFU-Es was inhibited. The inhibition by gangliosides was not abolished by increasing the dose of erythropoietin (10 U/ml). FACS-analysis studies with human CD34+ cells cultured with gangliosides (GM3), erythropoietin (EPO) and stem cell factor (SCF) demonstrated a strong inhibition on cell growth. This resulted in a significantly higher percentage of immature cells (CD34+/GpA-, 24% vs. 3%), and a lower percentage of mature erythroid cells (CD34-/GpA+, 36% vs. 89%). Under these circumstances the effects on erythroid cell growth were much higher than on other cell lineages. The inhibitory effect of gangliosides isolated from acute lymphoblastic leukemic patients on in vitro erythropoiesis suggests that in vivo hemopoietic suppression might have its origin in the gangliosides present and probably shed by the malignant cells in the microenvironment and plasma. Our results show that gangliosides inhibit erythropoiesis in vitro at several stages of development, by a mechanism involving modulation of the maturation of erythroid cells.

Topics: Animals; Antigens, CD34; Bone Marrow; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Female; Gangliosides; Humans; Leukemia; Mice; Mice, Inbred C57BL

The hypoxia-inducible factor-1 (HIF-1) is a transcriptional activator involved in the expression of oxygen-regulated genes such as that for erythropoietin. Following exposure to low oxygen partial pressure (hypoxia), HIF-1 binds to an hypoxia-response element located 3' to the erythropoietin gene and confers activation of erythropoietin expression. The conserved core HIF-1 binding site (HBS) of the erythropoietin 3' enhancer (CGTG) contains a CpG dinucleotide known to be a potential target of cytosine methylation. We found that methylation of the HBS abolishes HIF-1 DNA binding as well as hypoxic reporter gene activation, suggesting that a methylation-free HBS is mandatory for HIF-1 function. The in vivo methylation pattern of the erythropoietin 3' HBS in various human cell lines and mouse organs was assessed by genomic Southern blotting using a methylation-sensitive restriction enzyme. Whereas this site was essentially methylation-free in the erythropoietin-producing cell line Hep3B, a direct correlation between erythropoietin protein expression and the degree of erythropoietin 3' HBS methylation was found in different HepG2 sublines. However, the finding that this site is partially methylation-free in human cell lines and mouse tissues that do not express erythropoietin suggests that there might be a general selective pressure to keep this site methylation-free, independent of erythropoietin expression.

Topics: Animals; Binding Sites; Carcinoma, Hepatocellular; Cell Hypoxia; Cell Nucleus; Dinucleoside Phosphates; DNA Methylation; DNA-Binding Proteins; Erythropoietin; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Genes, Reporter; HeLa Cells; Humans; Hypoxia-Inducible Factor 1; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney; L Cells; Leukemia; Liver; Liver Neoplasms; Luciferases; Mice; Neuroblastoma; Nuclear Proteins; Organ Specificity; Recombinant Fusion Proteins; Transcription Factors; Transcriptional Activation; Transfection; Tumor Cells, Cultured

Topics: Acute Disease; Antineoplastic Combined Chemotherapy Protocols; Erythropoietin; Humans; Iron; Leukemia

Topics: Aged; Anemia, Refractory; Erythropoietin; Female; Humans; Leukemia; Lymphoproliferative Disorders; Male; Middle Aged; Recombinant Proteins; Waldenstrom Macroglobulinemia

We recently determined that erythropoietin (EPO) activates 3 members of the signal transducer and activator of transcription (STAT) family, Stat1alpha, Stat3, and Stat5, in the human EPO-dependent cell lines, UT-7 and UT-7/EPO (Kirito et al, J Biol Chem 272:16507, 1997). In addition, we have shown that Stat1alpha, but not Stat3, is involved in EPO-induced cellular proliferation. In this study, we examined the roles of Stat1alpha and Stat3 in EPO-induced erythroid differentiation. UT-7/GM was used as a model system, because this cell line can differentiate into erythroid-lineage cells with EPO treatment (Komatsu et al, Blood 89:4021, 1997). We found that EPO did not activate Stat1alpha or Stat3 in UT-7/GM cells. Transfection experiments showed that both Stat1alpha and Stat3 inhibited the induction by EPO of gamma-globin and erythroid-specific 5-aminolevulinate synthetase transcripts, resulting in a reduction of the percentage of hemoglobin-positive cells. Dominant negative forms of Stat1alpha or Stat3 promoted the EPO-induced erythroid differentiation of UT-7/GM cells, even in the presence of granulocyte-macrophage colony-stimulating factor, although this cytokine never induced erythroid differentiation of the parent UT-7/GM cells with or without EPO. A cell cycle analysis showed that the constitutive activation of Stat1alpha, but not Stat3, shortened the period of G0/G1 prolongation caused by EPO stimulation. Taken together, our data suggest that Stat1alpha and Stat3 act as negative regulators in EPO-induced erythroid differentiation. Specifically, Stat1alpha may activate a cell cycle-associated gene(s), leading to the entry of cells into the cell cycle.

Topics: Cell Differentiation; DNA-Binding Proteins; Erythrocytes; Erythropoietin; Humans; Interferon-Stimulated Gene Factor 3; Leukemia; Signal Transduction; STAT3 Transcription Factor; Trans-Activators; Transcription Factors; Tumor Cells, Cultured

A defect in erythropoietin (EPO) production has been advocated as being the main cause of anemia presented at time of diagnosis or during treatment by adults with solid tumors. On the basis of this defect, anemic cancer patients, both adults and children, have been treated with recombinant human EPO (rHuEPO). To further elucidate the pathophysiology of anemia in children with cancer, we measured serum soluble transferrin receptor (sTfR), a quantitative marker of erythropoiesis, and serum EPO at time of diagnosis and during chemotherapy in children suffering from solid tumor or leukemia. We determined serum EPO in 111 children (55 leukemia, 56 solid tumors) at time of diagnosis. In the last 44 patients (23 leukemia and 21 solid tumors), sTfR levels were also measured. Serum EPO together with sTfR levels were also determined in 60 children receiving chemotherapy (29 leukemia, 31 solid tumors). These results were compared with those obtained from appropriate control groups. In all patients, we found a highly significant correlation between the logarithm of EPO (log[EPO]) and the hemoglobin (Hb) level. In all subsets of patients, sTfR levels were inappropriately low for the degree of anemia. Neither leukemic nor solid tumor groups showed a significant inverse relationship between log(sTfR) and the Hb level as would be expected in anemic patients with appropriate marrow response. Thus, in children with cancer, anemia is associated with a decreased total bone marrow erythropoietic activity which, in contrast to what has been reported in anemic cancer adults, is not related to defective EPO production.

Topics: Adolescent; Anemia; Bone Marrow Cells; Child; Child, Preschool; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Female; Hemoglobins; Humans; Infant; Leukemia; Male; Neoplasms; Receptors, Transferrin

The plasma concentrations of erythropoietin (Ep), soluble transferrin receptors (sTfRs), iron, total iron binding capacity (TIBC) and ferritin were monitored in five leukaemia patients undergoing autologous bone marrow stem cell transplantation (BMSCT) and in 10 lymphoma and 21 ovarian cancer patients undergoing autologous peripheral blood SCT (PBSCT); 9/21 ovarian cancer patients received recombinant human G-CSF and Ep and six recombinant human GM-CSF and Ep following SCT. All parameters were evaluated in relation to the kinetics of erythroid reconstitution as evaluated by haemoglobin (Hb) and reticulocyte levels [including the fraction of immature reticulocytes, also called highly fluorescent reticulocytes (HFR)]. Leukaemia patients undergoing BMSCT showed only a delayed (occurring at days 35-50 after SCT) and partial RBC, neutrophil and platelet recovery, whereas all patients undergoing PBSCT exhibited a rapid (occurring at days 10-15 after SCT) and sustained haemopoietic recovery. The various levels of erythroid rescue observed among these patients markedly influenced the kinetics of the different parameters investigated: (i) in leukaemia BMSCT patients sTfRs declined following SCT and remained at low levels thereafter, whereas Ep, iron. TIBC and ferritin showed a progressive and significant increase; (ii) in the different groups of patients undergoing PBSCT: (a) sTfR levels first declined following SCT and then returned to pre-therapy values at days 12-16, this response preceded erythropoietic recovery; (b) Ep, total iron, TIBC and ferritin showed an initial increase in the first days following SCT and then returned to pre-therapy values. Altogether, these observations indicate that: (i) both sTfR levels and reticulocyte counts are predictive parameters of erythropoietic recovery; (ii) coordinated changes of biochemical parameters underlying iron metabolism (iron, TIBC and ferritin) accompany erythroid rescue following SCT.

Topics: Adolescent; Adult; Aged; Erythropoiesis; Erythropoietin; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Stem Cell Transplantation; Hemoglobins; Humans; Leukemia; Lymphoma; Male; Middle Aged; Ovarian Neoplasms; Receptors, Transferrin; Reticulocyte Count

Grb2/Ash is composed of one SH2 and two SH3 domains and functions as an adapter linking tyrosine-kinase receptors and Ras in fibroblasts. The SH2 domain binds to tyrosine-phosphorylated proteins and the SH3 domain binds to protein containing proline-rich regions. However, the mechanisms of signal transduction through Grb2/Ash in hematopoietic cells are still unclear. By means of the binding experiments using the GST fusion protein including the full length Grb2/Ash, we have found that Shc and unidentified 130-kDa and 135-kDa proteins are associated with Grb2/Ash and that they are tyrosine-phosphorylated by treatment with granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (EPO) in a human leukemia cell line UT-7. We have purified the 130-kDa protein (pp 130) using GST-GRB2/Ash affinity column. The amino-acid sequence analysis showed that the pp130 was identical to the human c-cbl proto-oncogene product (c-Cbl). c-Cbl constitutively binds to the SH3 domain of Grb2/Ash both in vitro and in vivo but not to the SH2 domain of Grb2/Ash. Moreover, c-Cbl (pp 130) becomes tyrosine-phosphorylated rapidly and transiently depending on GM-CSF and EPO stimulation. However, we could not find the homologous regions with guanine nucleotide exchange factors or GTPase-activating proteins in the c-cbl gene. These findings strongly suggest that c-Cbl is implicated in the signal transduction of GM-CSF and EPO in hematopoietic cells, and c-Cbl and Grb2/Ash might also transduce a signal that is different from the signal leading to Ras regulation. Recently, we have shown that the proto-oncogene vav product (Vav) is also tyrosine-phosphorylated by treatment with GM-CSF and EPO and is constitutively associated with the SH3 domain of Grb2/Ash in UT-7. Another guanine nucleotide exchange factor Sos is also associated with Grb2/Ash in UT-7. It has been reported that Vav has guanine nucleotide exchange activity and activates Ras in vitro and in vivo. These data suggest that tyrosine kinases, the adapter Grb2/Ash, and the guanine nucleotide exchange factor Vav and Sos are members of a signaling pathway leading to Ras activation in hematopoietic cells.

Topics: Adaptor Proteins, Signal Transducing; Cell Line; Chromatography, Affinity; ErbB Receptors; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; GRB2 Adaptor Protein; Hematopoiesis; Humans; Leukemia; Proteins; Proto-Oncogene Mas; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-cbl; Proto-Oncogenes; Recombinant Fusion Proteins; Signal Transduction; src Homology Domains; Ubiquitin-Protein Ligases

Topics: Adolescent; Adult; Blood Donors; Busulfan; Child; Child, Preschool; Cyclosporine; Erythropoietin; Female; Graft vs Host Disease; Granulocyte Colony-Stimulating Factor; Hematopoietic Stem Cell Transplantation; Histocompatibility Testing; Humans; Leukemia; Lymphoma; Lymphoproliferative Disorders; Male; Methotrexate; Middle Aged; Prednisolone; Whole-Body Irradiation

We serially determined serum erythropoietin (Epo) and the reticulocyte count in patients with various types of leukemia during chemotherapy. Serum Epo increased soon after the initiation of chemotherapy and decreased after the termination of therapy irrespective of the types of leukemia or treatment regimen. However, it did not stay at low level but fluctuated. The reticulocyte count, on the other hand, showed a transient rise while serum Epo level descended. The value of serum Epo when increased was higher than the value expected from hemoglobin concentration; this finding was similar to that in aplastic anemia. These results suggest that myelosuppression is a major factor for the increase in serum Epo level during leukemia chemotherapy.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Blood Cell Count; Erythropoietin; Female; Humans; Leukemia; Male; Middle Aged; Reticulocytes

The B-raf/c-Rmil proto-oncogene belongs to the raf/mil family of serine/threonine protein kinases. It encodes multiple protein isoforms previously shown to be expressed predominantly in neural tissues. We report here that B-Raf proteins of 95 and 72 kDa are also expressed in various human and murine hematopoietic cell lines. Their relative level of expression is variable depending on the cell line examined. The highest level of expression of p95B-raf was found in UT-7 cells, a human pluripotent cell line established from a patient with a megakaryoblastic leukemia. These cells are able to differentiate toward erythroid or myeloid lineage phenotypes in presence of erythropoietin (EPO) or granulocyte-macrophage colony-stimulating factor (GM-CSF) respectively. We show that treatment of UT-7 cells with EPO, GM-CSF or stem cell factor (SCF) rapidly induces phosphorylation of p95B-raf as indicated by a shift of electrophoretic mobility. This increase in phosphorylation is correlated with a three-fold increase of B-Raf kinase activity. B-Raf activation also increases in a dose-dependent manner in response to EPO and GM-CSF. We also show that both p95B-raf and p72B-raf can be activated by IL-3 in murine BAF-3 pro-B cells and by anti-CD3 in human Jurkat cells, respectively. These observations provide the first evidence that the B-Raf kinase is involved in signal transduction pathways regulating proliferation and differentiation of hematopoietic cells of both myeloid and lymphoid lineages.

Topics: Animals; Cell Line; Enzyme Activation; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Cell Growth Factors; Hematopoietic Stem Cells; Humans; Isoenzymes; Leukemia; Mice; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Mas; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-raf; Stem Cell Factor; Tumor Cells, Cultured

The vav proto-oncogene product (Vav) is expressed exclusively in hematopoietic cells and is reported to have guanine nucleotide exchange activity. Here we report that granulocyte-macrophage colony-stimulating factor, interleukin-3, and erythropoietin induce tyrosine phosphorylation of Vav in a human leukemia cell line UT-7. Tyrosine phosphorylation of Vav is rapid and transient; it occurs within 1 min of the stimulation and at physiological concentrations of the factors. Furthermore, we show that Vav is constitutively associated with the adapter molecule Grb2/Ash in UT-7. These data suggest that tyrosine kinases, the adapter Grb2/Ash, and the guanine nucleotide exchange factor Vav are members of a signaling pathway leading to Ras activation in hematopoietic cells.

Topics: Adaptor Proteins, Signal Transducing; Amino Acid Sequence; Cell Cycle Proteins; ErbB Receptors; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; GRB2 Adaptor Protein; Humans; Interleukin-3; Leukemia; Molecular Sequence Data; Neoplasm Proteins; Phosphorylation; Protein-Tyrosine Kinases; Proteins; Proto-Oncogene Mas; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-vav; Proto-Oncogene Proteins pp60(c-src); ras Proteins; Signal Transduction; Stimulation, Chemical; Tumor Cells, Cultured

Topics: Adult; Antisense Elements (Genetics); Base Sequence; Bone Marrow; Colony-Forming Units Assay; Erythropoiesis; Erythropoietin; Female; Fetal Blood; Genes, Homeobox; Hematopoietic Stem Cells; Humans; Leukemia; Molecular Sequence Data; Multigene Family; Pregnancy; Tumor Cells, Cultured

In order to delineate functionally important domains in erythropoietin (Epo), we have prepared and tested a series of amino acid replacements at 51 conserved sites predicted to be on the surface of the molecule. Alanine replacements permitted preservation of alpha-helical structure. Wild type and mutant Epo cDNAs were transiently expressed at high levels in COS1 and COS7 cells. The biological activity of wild type and mutant Epos was assayed in three Epo-responsive cell types: primary murine erythroid spleen cells, the murine HCD57 erythroleukemia cell line, and the human UT7-EPO leukemia cell line. When Arg14 on predicted Helix A was replaced by Ala, biological activity was substantially reduced, whereas replacement with Glu resulted in total loss of specific bioactivity. In a similar manner, the mutein Arg103-->Ala in Helix C was completely lacking in biological activity, whereas both Ser104-->Ala and Leu108-->Ala had decreased bioactivity. In Helix D, the mutein Gly151-->Ala had markedly decreased bioactivity, whereas that of the adjacent Lys152-->Ala mutein was moderately impaired. In contrast, Ala replacements at three nearby sites on Helix D (147, 146, and 143) resulted in muteins with increased bioactivity. In conclusion, our mutagenesis experiments have identified functionally important domains on the surface of the Epo molecule, at sites comparable with those established for other cytokines.

Topics: Amino Acid Sequence; Animals; Biological Assay; Cell Division; Cell Line; Chlorocebus aethiops; Erythropoietin; Humans; Leukemia; Leukemia, Erythroblastic, Acute; Mice; Models, Molecular; Molecular Sequence Data; Mutagenesis, Site-Directed; Point Mutation; Protein Structure, Secondary; Radioimmunoassay; Recombinant Proteins; Thymidine; Transfection; Tumor Cells, Cultured

Topics: Anemia; Biomarkers; Biopterins; Erythropoietin; Ferritins; Hemoglobins; HIV Infections; Humans; Interferon-gamma; Leukemia; Neoplasms; Neopterin; Reference Values

During the last three years 77 patients with myelofibrosis were studied by scintigraphy, using 99m Tc colloids and 111 In transferrin as tracers. Low axial uptake of the colloids, extension of the indium uptake beyond the axis towards the knees and sometimes the ankles and elbows, and splenic indium uptake are valuable diagnostic criteria, particularly useful to exclude myelofibrosis associated with a malignant disorder. The clinical severity of the disease, and in particular the disappearance of a physiologically active bone marrow (indium uptake) can be predicted from isotopic studies. Bone marrow scintigraphy could contribute to the difficult decision of splenectomy.

Topics: Adult; Bone Marrow; Erythropoietin; Female; Humans; Leukemia; Male; Middle Aged; Polycythemia Vera; Primary Myelofibrosis; Prognosis; Radionuclide Imaging; Splenomegaly; Thrombocythemia, Essential

A favorable prognosis and a low rate of leukemic transformation has been attributed to the 5q- syndrome, a myelodysplastic syndrome (MDS) characterized by macrocytic anemia, hypolobulated micromegakaryocytic hyperplasia, and an interstitial deletion of chromosome 5. We examined the characteristics and outcome of 43 consecutive patients in our institution strictly defined by morphologic criteria and a solitary 5q- cytogenetic defect. The median age at diagnosis was 68 years, with a clear female predominance (7:3). Eighty percent of the patients were red blood cell transfusion-dependent at diagnosis and all untransfused patients had macrocytic indexes. In contrast, significant neutropenia or thrombocytopenia was rare. The French-American-British (FAB) class distributions were RA (72%), RARS (7%), RAEB (16%), and RAEB-IT (5%). At a median follow-up of 31 months, 56% of the patients survive, with a projected median survival of 63 months. The incidence of acute leukemia was 16% and was uniformly fatal. Clinical hemosiderosis occurred in 28% of the patients, resulting in two deaths. Neither survival nor the risk of leukemic transformation was predictable from initial clinical parameters, including FAB classification, Bournemouth score, and degree of aneuploidy. The lack of significant neutropenia and thrombocytopenia seemed to account for a very low incidence of infection and bleeding resulting in a prognosis equal or superior to historical patients with MDS. Therapeutic endeavors, including the use of corticosteroids, androgens, cis-retinoic acid, pyridoxine, and danazol, were largely unsuccessful.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Blood Transfusion; Bone Marrow; Cell Transformation, Neoplastic; Chromosomes, Human, Pair 5; Erythropoietin; Female; Gene Deletion; Humans; Leukemia; Male; Middle Aged; Myelodysplastic Syndromes; Prognosis

Recombinant human erythropoietin (rhEpo) was given i.v. at a dose of 50 U/kg/tid to eight patients undergoing an HLA-matched, ABO-compatible bone marrow transplantation (BMT), from day +1 up to day +30. Compared to the data recorded in 13 similar BMT patients who had not received the hormone, the administration of rhEpo resulted in a faster erythroid engraftment: in fact, the time required to reach a stable hematocrit value greater than or equal to 35% decreased from 123.0 to 58.0 days after BMT. Moreover, the number of blood reticulocytes on day +21 was about fourfold greater in the rhEpo group than in the controls, while the number of the most immature, high RNA content reticulocytes (HFR), as determined by a flow cytometric technique, was more than sixfold greater; finally, the recovery time of both total and HFR reticulocytes was significantly reduced by rhEpo. The stimulation of erythroid progenitors also resulted in a reduction in red blood cell (RBC) transfusion requirements: the number of RBC units delivered in the first 30 days following BMT decreased from 8.1 in the controls to 4.0, while the total number of RBC units before transfusion independence was about threefold lower than in the control. Finally, the time of transfusion dependence was significantly shortened by rhEpo. No clinically significant adverse effect directly attributable to rhEpo was recorded. These data suggest that the administration of rhEpo may be beneficial in hastening erythroid engraftment, and possibly in reducing RBC transfusion requirements following BMT.

Topics: ABO Blood-Group System; Adolescent; Adult; Blood Cell Count; Blood Component Transfusion; Bone Marrow Transplantation; Erythroid Precursor Cells; Erythropoietin; Female; Graft Survival; Histocompatibility; HLA Antigens; Humans; Leukemia; Male; Middle Aged; Recombinant Proteins; Reticulocytes; Transplantation, Homologous

We have established a new nonlymphoid leukemic cell ine from a patient with myelodysplastic syndrome (MDS), which progressed to overt leukemia. The parental cell line and a subline derived from this line have absolute dependency on several cytokines for their long-term survival and growth. The parental line designated F-36P requires granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) for continuous growth, while a subline designated F-36E can be maintained in the presence of erythropoietin (Epo) alone. When these cytokines are depleted, both the parental and the subline cells die within several days, even in medium supplemented with fetal calf serum (FCS). F-36E, maintained in the presence of Epo, constitutively synthesizes hemoglobin at a significant level. F-36P, which is usually maintained in the presence of GM-CSF or IL-3, can be induced to synthesize hemoglobin when GM-CSF or IL-3 is substituted by Epo. The surface marker profile shows that the F-36P cells are positive for the leukocyte common antigen (CD45) and some common multilineage markers such as CD13, CD33, and CD34, and negative for T- and B-cell antigens and mature myelomonocytic antigens. However, some monoclonal antibodies recognizing erythroid and platelet glycoproteins react with these cells. Thus, this cell line has a multilineage phenotype, suggesting that the transformation event occurred in a multipotent stem cell. It is also evident that the F-36 cells can be induced to differentiate into the erythroid lineage in the presence of Epo. This, to our knowledge, is the first description of a human leukemic cell line that can be stimulated to synthesize hemoglobin by Epo.

Topics: Antigens, Surface; Cell Differentiation; Cell Division; Cell Survival; Erythrocytes; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; Hemoglobins; Histocytochemistry; Humans; Interleukin-3; Karyotyping; Leukemia; Male; Microscopy, Electron; Myelodysplastic Syndromes; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; Tumor Cells, Cultured

The Friend or Moloney mink cell focus-forming (MCF) virus encodes a recombinant-type envelope glycoprotein, gp70, that is closely related to the membrane glycoprotein, gp55, of Friend spleen focus-forming virus (SFFV). We have shown previously that gp55 has the ability to activate cell growth by binding to the cellular receptor for erythropoietin. Here we show that gp70 encoded by either the Friend or Moloney MCF virus also binds to the erythropoietin receptor and that coexpression of the receptor and gp70 in an interleukin-3 (IL-3)-dependent cell line can activate IL-3-independent growth. Furthermore, when the cDNA for the human IL-2 receptor beta chain, which is related by sequence to the erythropoietin receptor, was introduced into this cell line, it became growth factor independent after infection either with SFFV or with one of the two MCF viruses but not with an ecotropic virus. Based on these observations, we propose a mechanism for the early stage of leukemogenesis induced by the MCF-type murine leukemia viruses.

Topics: Animals; Cell Division; Cell Line; Cell Transformation, Neoplastic; Cell Transformation, Viral; Electrophoresis, Polyacrylamide Gel; Erythropoietin; Friend murine leukemia virus; Humans; Interleukin-3; Leukemia; Mice; Mink Cell Focus-Inducing Viruses; Moloney murine leukemia virus; Receptors, Cell Surface; Receptors, Erythropoietin; Receptors, Interleukin-2; Retroviridae Proteins, Oncogenic; Viral Envelope Proteins

Serial serum erythropoietin levels were measured in 10 consecutive patients undergoing allogeneic bone marrow transplantation. Observed erythropoietin levels are compared with those predicted from a large control population of anaemic patients not receiving chemotherapy. There was an initial acute rise in serum erythropoietin, peaking between days 1 and 4 after marrow transfusion, which was unrelated to changes in haemoglobin concentration. Patients maintained serum erythropoietin concentrations at around twice the predicted level for the first 2 weeks following transplantation, with a gradual fall into the expected range by wk 3. Erythropoietin levels did not change with episodes of bacterial infection or acute graft-versus-host disease. A patient with severe aplastic anaemia had initial successful engraftment with normalisation of erythropoietin levels, but showed a marked and amplified rise in erythropoietin 2 wk before falling peripheral blood counts indicated failure of the bone marrow graft.

Topics: Adolescent; Adult; Anemia, Aplastic; Bone Marrow; Bone Marrow Transplantation; Child; Cyclosporins; Erythropoietin; Female; Hemoglobins; Humans; Infant; Leukemia; Male; Middle Aged; Radiography; Radioimmunoassay

Knowledge of the endogenous blood level of erythropoietin (Epo) has gained recent interest in view of the advances in Epo replacement therapy in anemic patients. By radioimmunoassay, we have carried out comparative measurements of the serum Epo level in patients suffering from chronic enterocolitis or leukemia. In chronic enterocolitis, the Epo level showed an exponential increase with the degree of anemia (up to 250 U Epo/1 serum at 70 g hemoglobin/1 blood). Similarly anemic patients with leukemia and severe bone marrow insufficiency of erythropoiesis had much higher Epo levels (usually above 500 U/1). Our findings indicate that the level of Epo is not only dependent on the blood hemoglobin concentration but also on the type of anemia. In fact, additional in vitro studies showed that immunomodulatory peptides can significantly influence the production of Epo in the hepatoma cell culture HepG2.

Topics: Adult; Anemia, Hemolytic; Carcinoma, Hepatocellular; Enterocolitis; Erythropoietin; Humans; Interferon-gamma; Interleukin-1; Leukemia; Liver Neoplasms; Radioimmunoassay; Recombinant Proteins; Tumor Cells, Cultured

Sequential changes in serum erythropoietin (sEPO) levels were measured by radioimmunoassay in six patients receiving autologous rescue (AR) and 11 patients receiving an allogeneic bone marrow transplant (BMT) for malignant disease. Longitudinal studies showed an inverse relationship between sEPO and haemoglobin levels in the autologous rescue and allogeneic transplant patients throughout the 130 d post-transplant study period. Early post-conditioning EPO responses were normal for the haemoglobin level in both groups, but after day 14 post-transplant, erythropoietin production in response to anaemia became impaired in one autologous rescue patient and eight of the 11 allogeneic transplant patients. There was no clear association between late impairment of sEPO production and conditioning therapy, infection, graft-versus-host disease, immunosuppressive therapy or serum creatinine. Blood transfusion requirements were similar for both groups in the first month after transplantation, but from days 31 to 90 post-transplant, BMT patients required an average of 5.5 units per patient compared with 1 unit per patient for the autologous group. Marrow transplant procedures do not affect early EPO responses but may diminish late responses. The potential value of exogenous rHuEPO in hastening engraftment and decreasing transfusion requirements, particularly for those patients who appear to have impaired EPO responses, remains to be shown by clinical trials.

Topics: Adolescent; Adult; Bone Marrow Transplantation; Erythropoietin; Female; Hemoglobins; Humans; Leukemia; Longitudinal Studies; Male; Middle Aged; Postoperative Complications; Postoperative Period; Radioimmunoassay; Transplantation, Autologous; Transplantation, Homologous

Topics: Bone Marrow; Colitis, Ulcerative; Crohn Disease; Erythropoiesis; Erythropoietin; Hematologic Diseases; Humans; Leukemia

The dependence of the serum erythropoietin (Epo) level on the blood hemoglobin concentration was compared in patients suffering from leukemia and ulcerative colitis. In leukemia, the level of immunoreactive and bioactive Epo was generally much higher than in ulcerative colitis at comparable degrees of anemia. The highest Epo values were found in patients with severe bone marrow insufficiency of erythropoiesis. These findings support the hypothesis that the plasma level of Epo depends not only on the hemoglobin concentration of the blood but is also influenced by the proliferative activity of the erythron.

Topics: Anemia; Animals; Colitis, Ulcerative; Erythropoiesis; Erythropoietin; Gastrointestinal Hemorrhage; Hemoglobins; Humans; Leukemia; Mice; Polycythemia Vera

Topics: Antineoplastic Agents; Bone Marrow Transplantation; Erythropoietin; Humans; Leukemia

The question as to whether the serum concentration of erythropoietin is relatively high for the degree of anemia in patients with erythrocytic hypoplasia has regained interest, since recombinant human-like erythropoietin has become available as a drug for replacement therapy. We have compared the concentration of serum immunoreactive erythropoietin in nonrenal anemic patients with erythrocytic hypoplasia (22 cases) or active erythropoiesis (82 cases). In both groups a negative correlation was determined between the blood hemoglobin concentration and the logarithm of the erythropoietin concentration. However, the two regression lines were not identical, and the serum erythropoietin concentration was significantly higher for the degree of anemia in the patients with erythrocytic hypoplasia. Additional measurements in four patients suffering from acute leukemia with marrow failure showed that the erythropoietin concentration decreased towards the values observed in anemic patients with active erythropoiesis when the erythron recovered in the early phase of complete remission. These data support the idea that, independent of the O2 offer, the proliferating erythrocytic progenitors by negative feedback lower the blood level of erythropoietin.

Topics: Adult; Anemia, Aplastic; Bone Marrow Cells; Erythropoiesis; Erythropoietin; Female; Hemoglobins; Humans; Leukemia; Male; Radioimmunoassay; Regression Analysis

Topics: Colony-Stimulating Factors; Congenital Abnormalities; DNA; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Growth Substances; Humans; Leukemia; Myelodysplastic Syndromes; Oncogenes

The erythropoietin level was measured, by bioassay in polycythaemic mice, in the serum of anaemic patients suffering from different types of leukaemia. Comparative measurements were carried out in patients with ulcerative colitis. Serum erythropoietin was less well-correlated with the haemoglobin concentration in leukaemia than in ulcerative colitis. While serum erythropoietin did not exceed 200 mU/ml in patients with ulcerative colitis (lowest blood haemoglobin concentration 56 g/l), several of the leukaemic patients had serum erythropoietin levels above 500 mU/ml at comparable degrees of anaemia. Bone marrow biopsy showed that erythropoiesis was severely impaired in the leukaemic patients whose erythropoietin values were relatively high. These findings are in accord with the hypothesis that the plasma level of erythropoietin depends not only on the haemoglobin concentration of the blood but also on the bone marrow responsiveness to the hormone.

Topics: Adolescent; Adult; Aged; Anemia; Animals; Colitis, Ulcerative; Erythropoiesis; Erythropoietin; Female; Hemoglobins; Humans; Leukemia; Male; Mice; Middle Aged

Serial erythropoietin measurements by RIA were performed in six patients with acute leukemia treated by intensive chemotherapy. In all cases erythropoietin titers increased after the onset of treatment, although the hemoglobin concentration remained at stable values. Subsequently the erythropoietin titers gradually returned to baseline levels. In same patients this reduction occurred at the end of chemotherapy, in others coincident with infections and antibiotic therapy. In four patients this decrease occurred at the time of bone marrow recovery. The explanation for this inappropriate increase in erythropoietin titers is not clear but may be related to a direct or indirect effect of a suppressed marrow on sites of erythropoietin production or catabolism.

Topics: Adult; Aged; Antineoplastic Agents; Asparaginase; Cyclophosphamide; Cytarabine; Daunorubicin; Erythropoietin; Female; Humans; Leukemia; Leukemia, Myeloid, Acute; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Prednisone; Vincristine

A new cell line of human erythroleukemia cells differentiates spontaneously so that 30% of the cells are always hemoglobinized. Erythropoietin did not affect the percentage of such cells but stimulated the cell growth, indicating that the cells have functioning receptors. Binding of human recombinant radioiodinated erythropoietin to the receptors was specific. The bound ligand was internalized into cells at 37 degrees C but not at 15 degrees C. Scatchard analysis showed two classes of binding sites. Covalent binding of erythropoietin to its receptors yielded two products detected on sodium dodecyl sulfate-polyacrylamide gels electrophoresed under reducing conditions. Under non-reducing conditions, these species disappeared and larger products appeared.

Topics: Cell Differentiation; Cell Division; Cell Line; Chronic Disease; Erythropoietin; Humans; Kinetics; Leukemia; Leukemia, Erythroblastic, Acute; Receptors, Cell Surface; Receptors, Erythropoietin; Recombinant Proteins

Erythroid colonies from five patients with an early erythroblastic leukemia were obtained in "serum-free" cultures in the presence or absence of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) and homogeneous native erythropoietin (Epo). Erythroid colonies with abnormal morphology and karyotype could be grown in different culture conditions. Their erythroid nature was ascertained by the presence of carbonic anhydrase I and glycophorin A. Leukemic erythroid progenitors strongly differed from normal progenitors in that spontaneous colonies were always obtained, sometimes with an extremely high plating efficiency (up to 5.7%). Colonies were found to be autonomous from exogenous hematopoietic growth factors because they were still obtained with a high plating efficiency at an average of one cell per culture in the absence of any added growth factor. No evidence for an autocrine secretion of Epo or GM-CSF emerged because Epo or GM-CSF could not be detected by biologic or radioimmunologic assays from the culture supernatant or cellular extracts of the leukemic cells and that Epo or GM-CSF antibodies did not block autonomous growth. In all cases, however, hematopoietic growth factors increased the plating efficiency of the abnormal erythroid progenitors. In the two "de novo" leukemias, leukemic erythroid progenitors responded primarily to Epo, whereas in the three other patients' (chronic myeloid leukemia) blast crisis they responded maximally to GM-CSF plus Epo. Recombinant erythroid-potentiating activity had no effect in any of these cases. These results suggest that the leukemic erythroid clonogenic cells arise from expansion of erythroid progenitors at different levels of differentiation (ie, CFU-E or BFU-E, depending upon the disease) and that autonomous growth is not related to a secretion of Epo or GM-CSF.

Topics: Cell Cycle; Cell Division; Colony-Stimulating Factors; Erythrocytes; Erythropoietin; Granulocytes; Hematopoietic Stem Cells; Humans; Karyotyping; Leukemia; Lymphokines; Macrophages; Recombinant Proteins; Tissue Inhibitor of Metalloproteinases

Topics: Animals; Cell Communication; Cell Differentiation; Cell Line; Cell Transformation, Viral; Chromosome Aberrations; Colony-Stimulating Factors; Erythropoiesis; Erythropoietin; Hematopoiesis; Hematopoietic Stem Cells; Leukemia; Lymphokines; Mice; Recombinant Proteins; Transfection

The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

Topics: Acute Disease; Blast Crisis; Cells, Cultured; Erythropoietin; Hematopoietic Stem Cells; Humans; Karyotyping; Leukemia; Male; Microscopy, Electron; Middle Aged

Erythropoiesis was evaluated in 5 cats at base line with normal PCV and then in the same cats with anemia induced by phlebotomy and in 5 other cats with nonregenerative anemia from community-acquired feline leukemia virus (FeLV) infection. The hematologic evaluation included complete blood cell and reticulocyte counts, marrow morphologic features, determination of serum erythropoietin concentrations by radioimmunoassay, ferrokinetic studies, and in vitro marrow culture of early erythroid progenitors (erythroid burst-forming units; BFU-E) and late erythroid progenitors (erythroid colony-forming units; CFU-E). Phlebotomized cats developed marrow erythroid hyperplasia and an increased reticulocyte count. Ferrokinetic studies revealed an increase in plasma iron turnover from 1.4 to 3.8 mg of Fe/dl of blood/day and RBC use from 50.4% to 78.5%. The mean CFU-E number and CFU-E/BFU-E ratio increased after phlebotomy, but the increase was not significant (P greater than 0.05). Serum erythropoietin values did increase significantly. In FeLV-infected cats, a nonregenerative anemia was demonstrated by marrow erythroid hypoplasia and a low total reticulocyte count. An increased percentage of rubriblasts and prorubricytes was observed in 4 of the 5 cats. Although serum erythropoietin values were high (321 +/- 123 mU/ml vs normal 14 +/- 1 mU/ml), ferrokinetic data revealed decreased erythropoiesis. Marrow culture studies in the FeLV-infected cats also revealed low numbers of BFU-E and CFU-E, but normal numbers of granulocyte-macrophage progenitors remained. Seemingly, the FeLV infection impaired the ability of feline marrow to respond physiologically to anemia.

Topics: Anemia; Animals; Biopsy, Needle; Bone Marrow; Cat Diseases; Cats; Erythropoiesis; Erythropoietin; Female; Iron; Kinetics; Leukemia; Leukemia Virus, Feline; Male; Reference Values; Regression Analysis

To test the hypothesis of renin substrate (RS; angiotensinogen) being a precursor of erythropoietin (EP), the capacity of RS and EP to induce Hb synthesis was compared in cultured human erythroid leukaemia cells of the K 562 line after prestimulation with haemin. For this purpose a radioimmunoassay for haemoglobin F (HbF) was developed. This assay was shown to be specific for HbF, reproducible, and sensitive for 0.1 ng of HbF. The cells were induced by RS and EP to increased HbF production. Cells stimulated with RS or EP showed increased benzidine staining. This data, corroborating our earlier observations on immunological similarities between RS and EP, supports the hypothesis that renin substrate is a likely precursor of erythropoietin.

Topics: Angiotensinogen; Angiotensins; Cell Line; Erythropoietin; Fetal Hemoglobin; Humans; Leukemia; Radioimmunoassay

Patients with various types of anaemia, but with comparable haemoglobin levels, show a wide range of serum erythropoietic activity. We have developed a method for the fractionation of serum by HPLC followed by bioassay of the individual fractions, using the mouse spleen cell microassay. Up to three distinct peaks of erythropoietic activity corresponding to molecular weights (MW) greater than 300,000, 250,000-300,000 and 40,000 have been found in serum from both normal and anaemic subjects. The erythropoietic profiles of the sera examined differ markedly in anaemias of different aetiology. The chemical nature and the physiological significance of the stimulators remain to be investigated.

Topics: Adolescent; Aged; Anemia; Anemia, Aplastic; Anemia, Megaloblastic; Animals; Biological Assay; Chromatography, High Pressure Liquid; Erythropoietin; Female; Hemoglobins; Humans; Leukemia; Male; Mice; Mice, Inbred C57BL; Middle Aged; Spleen

Erythropoietin concentrations were increased significantly (p less than 0.025) in nine cats with natural feline leukemia virus infection and associated erythroid aplasia compared to six clinically normal cats. Adult cats experimentally inoculated with the Kawakami-Theilen isolate of feline leukemia virus developed a progressive simultaneous increase in erythropoietin activity and decrease in packed cell volume. These findings indicate that erythroid aplasia associated with feline leukemia virus infection is not caused by a failure in erythropoietin production.

Topics: Anemia, Aplastic; Animals; Cat Diseases; Cats; Erythropoietin; Female; Hematocrit; Leukemia; Leukemia Virus, Feline; Male; Methylprednisolone; Methylprednisolone Acetate; Specific Pathogen-Free Organisms

In order the investigate mechanisms of diminished red cell production in malignancy, we assayed erythroid progenitor cell proliferative responses to erythropoietin in plasma clot cultures of bone marrow cells from 34 cancer patients. Erythroid colony growth by marrow cells of 11 healthy donors (means of 58 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) was similar to that in cultures of cells from patients either with (means of 44 CFU-E and 22 BFU-E derived colonies/6 X 10(4) cells) or without (means of 50 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) myelophthisis. Colony formation was normal at all erythropoietin concentrations tested, indicating that both the CFU-E and BFU-E retain normal erythropoietin sensitivity in vitro. CFU-E proliferation correlated negatively (r = -0.56; P less than 0.001) with the level of hemoglobin. In contrast to marrow cell proliferative responses to erythropoietin, serum erythropoietin levels were inappropriately reduced in all 19 patients in whom they were measured, a finding which may be important in the pathogenesis of anemia in patients with cancer.

Topics: Carcinoma, Squamous Cell; Cell Division; Cells, Cultured; Erythropoiesis; Erythropoietin; Female; Hematologic Diseases; Hematopoietic Stem Cells; Hemoglobins; Humans; Leukemia; Lymphoma; Male; Middle Aged

Eleven human T cell leukemia-lymphoma cell lines were tested to determine whether or not they released a product into their media which could stimulate erythroid colony formation by human peripheral blood mononuclear cells. None of the cell lines studied released erythroid burst-promoting activity detectable in our culture conditions.

Topics: Cell Line; Culture Media; Erythropoiesis; Erythropoietin; Humans; Leukemia; Lymphoma; T-Lymphocytes

Topics: Adolescent; Adult; Aged; Anemia, Aplastic; Bone Marrow; Child; Child, Preschool; Erythropoietin; Humans; Infant; Iron; Leukemia; Middle Aged

The results from a biological test for erythropoietin (using the rate of iron absorption in polycythemic mice) and a commercially-available immunological test (haemagglutination-inhibition test) were compared. Of 19 batches of the immunological test which were investigated, 7 batches were completely inactive and a further 3 batches reacted only with the test serum supplied with the test. There was a poor correlation between the results from the biological and the immunological measurements, both on patients with high and those with low serum erythropoietin levels. The difficulty of the immunological erythropoietin test is that pure erythropoietin is not sufficiently available. The immunological test investigated here does not use pure erythropoietin. Aside from this, pathophysiological considerations would lead one to expect basic differences between the results from immunological and biological tests.

Topics: Adrenal Gland Neoplasms; Anemia, Aplastic; Erythropoietin; Hemagglutination Inhibition Tests; Humans; Kidney Failure, Chronic; Leukemia; Pheochromocytoma; Polycythemia Vera

Hemopoietic populations offer by far the best available model systems for analyzing many aspects of the fundamental mechanisms controlling cell proliferation and differentiation. Semisolid cloning systems of high plating efficiency exist for normal and leukemic hemopoietic populations, and in these culture systems both proliferation and differentiation occur under defined culture conditions. Furthermore, the various differentiated end cells differ so extremely in morphology, membrane markers, and functional activity that a wide variety of parameters is available for monitoring differentiation. For the erythroid and granulocyte-macrophage systems, specific progenitor cells can be stimulated to generate large clones of differentiating progeny using the purified glycoprotein regulators erythropoietin, GM-CSF, and M-CSF. Exploitation of these systems will provide information on the events leading to proliferation and differentiation that should have general relevance for many other cell systems.

Topics: Animals; Cell Differentiation; Cell Division; Cells, Cultured; Clone Cells; Erythropoietin; Granulocytes; Hematopoiesis; Hematopoietic Stem Cells; Humans; Leukemia; Spleen

Topics: Alkylating Agents; Erythropoietin; Hematocrit; Hemorrhage; Humans; Leukemia; Polycythemia; Polycythemia Vera; Smoking; Thromboembolism

Topics: Age Factors; Anemia, Hemolytic; Animals; Child; Chronic Disease; Erythropoietin; Female; Humans; Kidney Diseases; Leukemia; Male; Mice; Mice, Inbred BALB C

We have reviewed erythroid cell differentiation from two points of view: 1) differences between fetal and adult human red cells with particular reference to alterations which can occur in the normal pattern of erythroid cell development during the course of leukemia; 2) beochemical events which occur during erythroid cell maturation, as a model system for the study of the control of gene expression. During the course of many leukemias there is the synthesis of red cells containing fetal hemoglobin. In most cases this phenomenon is limited to a small population or clone of red cells and probably represents a nonspecific response of the bone marrow to a hematologic stress. However, in juvenile chronic myeloid leukemia and, in rare cases of erythroleukemia, there is a major reversion to fetal erythropoiesis, with progressive increase in fetal hemoglobin levels and synthesis of red cells which contain not only fetal hemoglobin but have a true fetal pattern of protein synthesis affecting proteins other than Hb F, namely Hb A2, carbonic anhydrase and the membrane antigens i and I. In this case, the fetal erythropoiesis may be a more specific manifestation of the leukemic process and may be related to the phenomenon of fetal protein synthesis (alpha-fetoprotein of carcinoembryonic antigen) observed in other types of neoplasia. Further information on the etiology and pathogenesis of abnormal cell proliferation and differentiation in the leukemias can be obtained by the study of experimental systems permitting the investigation of the regulation of gene expression in differentiating mammalian cells. Maturing erythroid cells provide a promising system for such investigations for many reasons: differentiating erythroid cells can be obtained relatively free of other cell types; a large amount of a well characterized product, hemoglobin, is synthesized; techniques are now available that permit isolation of erythroid precursors at different stages of differentiation (5-8); and finally, highly sensitive methods of measuring globin mRNA levels by DNA-RNA hybridization are currently available (13, 26, 27). We have used such techniques to measure levels of globin mRNA in separated populations of murine erythroid cells at different stages of maturation. These studies demonstrated a correlation between globin mRNA content and degree of morphological maturation. In the least well differentiated cells, however, there appeared to be a disproportionate amount of mRNA for the lev

Topics: Anemia, Hemolytic; Animals; Blood Cell Count; Cell Differentiation; Cell Division; Erythrocytes; Erythropoiesis; Erythropoietin; Female; Fetal Hemoglobin; Genes; Globins; Hematopoietic Stem Cells; Heme; Hemoglobin H; Humans; Leukemia; Leukemia, Erythroblastic, Acute; Mice; Phenylhydrazines; RNA, Messenger; Time Factors

Erythropoietin level in the serum and urine of adult patients with acute leukaemia (AML, ALL, MML) was estimated by polycythaemic mouse bioassay in order to obtain more information about the associated anaemia. In AML and ALL patients the serum erythropoietin level as found to be increased and in a negative correlation with the blood haemoglobin concentration. In ALL patients erythropoietin in urine was increased regularly while in AML patients it was not. No correlation between the serum level and the urinary excretion of ESF, or between the blood Hb and the serum ESF, was found in MML patients. The results show that anaemia in leukaemia is not due to the low ESF level.

Topics: Acute Disease; Adult; Anemia; Animals; Erythropoiesis; Erythropoietin; Humans; Iron; Leukemia; Leukemia, Lymphoid; Leukemia, Monocytic, Acute; Leukemia, Myeloid, Acute; Mice; Mice, Inbred CBA

Topics: Blood Transfusion; Bloodletting; Bone Marrow; Bone Marrow Cells; Chlorambucil; Chronic Disease; Erythrocytes; Erythropoietin; Female; Humans; Leukemia; Liver; Male; Phosphorus Radioisotopes; Polycythemia; Polycythemia Vera; Spleen; United States

Topics: Adrenocorticotropic Hormone; Animals; Cell Differentiation; Cell Division; Cyclic AMP; DNA; DNA Replication; Erythropoietin; Feedback; Growth Inhibitors; Hematopoietic Stem Cells; Hematopoietic System; Homeostasis; Humans; Leukemia; Neoplasms, Experimental; Rabbits; Rats; RNA

Topics: Acute Disease; Adolescent; Child; Child, Preschool; Erythropoiesis; Erythropoietin; Hodgkin Disease; Humans; Infant; Leukemia; Leukemia, Myeloid

Topics: Adolescent; Adult; Aged; Anemia, Aplastic; Anemia, Hemolytic; Anemia, Sickle Cell; Bone Marrow Diseases; Creatinine; Erythropoietin; Female; Hematocrit; Hemolysis; Humans; Iron; Leukemia; Lymphoma; Male; Middle Aged; Multiple Myeloma; Sex Factors

Topics: Acute Disease; Anemia, Aplastic; Child; Erythropoietin; Hemoglobins; Humans; Leukemia

Topics: Alpharetrovirus; Animals; Biological Assay; Cell Transformation, Neoplastic; Erythropoietin; Friend murine leukemia virus; Helper Viruses; Humans; Leukemia; Leukemia Virus, Murine; Leukemia, Experimental; Leukemia, Lymphoid; Mice; Polycythemia; Splenic Neoplasms

Topics: Anemia; Anemia, Aplastic; Anemia, Sickle Cell; Animals; Biological Assay; Breast Neoplasms; Cachexia; Erythrocytes; Erythropoiesis; Erythropoietin; Iron; Iron Isotopes; Leukemia; Lymphoma; Male; Mice; Plasma; Polycythemia; Prostatic Neoplasms

Topics: Acute Disease; Anemia, Aplastic; Animals; Biological Assay; Bone Marrow; Bone Marrow Cells; Bone Marrow Diseases; Erythropoiesis; Erythropoietin; gamma-Globulins; Hodgkin Disease; Humans; Iron Isotopes; Leukemia; Mediastinal Neoplasms; Mice; Osteosarcoma; Thymoma

Topics: Animals; Erythropoietin; Hemoglobinometry; Humans; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Mice

Topics: Animals; Erythropoiesis; Erythropoietin; Hodgkin Disease; Humans; Immunoglobulin M; Leukemia; Mice; Polycythemia; Prognosis

Topics: Adult; Aged; Anemia, Aplastic; Animals; Bone Marrow Diseases; Erythropoiesis; Erythropoietin; Female; Hematologic Diseases; Humans; Leukemia; Male; Middle Aged; Rats

Topics: Adult; Anemia; Animals; Child; Erythropoietin; Fasting; Female; Hemoglobinometry; Humans; Hyperthyroidism; Iron Isotopes; Kidney Diseases; Leukemia; Liver Diseases; Rabbits; Rats; Staphylococcal Infections; Streptococcal Infections

Topics: Anemia, Aplastic; Anemia, Hemolytic; Anemia, Hypochromic; Animals; Erythropoietin; Hodgkin Disease; Humans; Infant; Infant, Newborn; Leukemia; Lymphatic System; Mice; Mononuclear Phagocyte System; Polycythemia; Umbilical Cord

Topics: Animals; Erythropoietin; Female; Humans; Leukemia; Male; Rats; Thalassemia

Topics: Biological Assay; Blood; Epoetin Alfa; Erythropoietin; Humans; Leukemia; Rats

Topics: Anemia; Anemia, Hemolytic; Anemia, Hypochromic; Anemia, Pernicious; Blood Coagulation; Blood Proteins; Chloramphenicol; Epidemiology; Epoetin Alfa; Erythropoietin; Haptoglobins; Hematologic Diseases; Hematology; Hemochromatosis; Humans; Iron-Dextran Complex; Leukemia; Polycythemia; Thromboplastin; Vitamin B 12

Topics: Bone Marrow; Epoetin Alfa; Erythropoietin; In Vitro Techniques; Leukemia; Leukemia, Myeloid; Monocytes; Pharmacology; Research; Synovial Membrane; Tissue Culture Techniques

Topics: Anemia; Anemia, Aplastic; Blood Transfusion; Epoetin Alfa; Erythropoiesis; Erythropoietin; Humans; Leukemia; Leukemia, Lymphoid; Metabolism

Topics: Alpha-Globulins; Anemia; Antibodies; Biological Assay; Blood; Cerebellar Neoplasms; Electrophoresis; Epoetin Alfa; Erythropoiesis; Erythropoietin; Exudates and Transudates; Hemangiosarcoma; Humans; Hypoxia; Immune Sera; Kidney; Kidney Diseases, Cystic; Leukemia; Leukemia, Lymphoid; Neuraminidase; Trypsin

Topics: Anemia; Anemia, Aplastic; Blood Chemical Analysis; Body Fluids; Epoetin Alfa; Erythropoietin; Humans; Leukemia; Urine

Topics: Anemia; Anemia, Aplastic; Aorta; Cell Division; Epoetin Alfa; Erythropoietin; Humans; Leukemia; Metabolism