phosphorus-radioisotopes and Leukemia--Myeloid--Acute

Polycythemia vera, essential thrombocythemia, and primary myleofibrosis are chronic myeloproliferative neoplasms (MPNs) associated with an increased morbidity and mortality. MPNs are also associated with progression to acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS). The "true" rate of transformation is not known mainly due to selection bias in clinical trials and underreporting in population-based studies. The outcome after transformation is dismal. The underlying mechanisms of transformation are incompletely understood and in part remain an area of controversy. There is an intrinsic propensity in MPNs to progress to AML/MDS, the magnitude of which is not fully known, supporting a role for nontreatment-related factors. High doses of alkylating agents, P(32) and combined cytoreductive treatments undoubtedly increase the risk of transformation. The potential leukemogenic role of hydroxyurea has been a matter of debate due to difficulties in performing large prospective randomized trials addressing this issue. The main focus of this review is to elucidate therapy-related leukemic transformation in MPNs with a special focus on the role of hydroxyurea.

Topics: Antineoplastic Agents; Cell Transformation, Neoplastic; Disease Progression; Humans; Hydroxyurea; Janus Kinase 2; Leukemia, Myeloid, Acute; Mutation; Myelodysplastic Syndromes; Phosphorus Radioisotopes; Polycythemia Vera; Primary Myelofibrosis; Survival Analysis; Thrombocythemia, Essential

Hydroxyurea is an old drug that is often used to control essential thrombocythemia and polycythemia vera in patients with high-risk disease. It is usually well tolerated and cheap and has been proven effective in many studies for the prevention of thrombohemorrhagic complications associated with these disorders. However, many clinicians are reluctant to use it because of the perceived risk of progression to acute leukemia. Several recent, large studies have given this drug a new lease on life. Relevant results from these studies are discussed, and the risk of leukemia is placed in perspective to demonstrate that hydroxyurea remains the drug of choice in patients with either of these disorders.

Topics: Aged; Agranulocytosis; Alkylating Agents; Clinical Trials as Topic; Combined Modality Therapy; Disease Progression; Evidence-Based Medicine; Hemorrhage; Humans; Hydroxyurea; Leukemia, Myeloid, Acute; Middle Aged; Phlebotomy; Phosphorus Radioisotopes; Polycythemia Vera; Thrombocythemia, Essential; Thrombophilia

Topics: Animals; Bone Marrow; Bone Marrow Cells; Cell Survival; Dogs; Granulocytes; Half-Life; Hematopoiesis; Humans; In Vitro Techniques; Injections, Intramuscular; Injections, Intravenous; Isoflurophate; Kinetics; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukocytes; Methods; Neutropenia; Neutrophils; Phosphorus Radioisotopes; Remission, Spontaneous; Time Factors

Topics: Anemia; Anemia, Sideroblastic; Animals; Chromosome Aberrations; Chromosome Disorders; Female; Granulocytes; Hematologic Diseases; Humans; Japan; Leukemia; Leukemia, Erythroblastic, Acute; Leukemia, Myeloid, Acute; Male; Mice; Middle Aged; Nuclear Warfare; Phosphorus Radioisotopes; Polycythemia Vera; Precancerous Conditions; Radiation Injuries; Thrombocytopenia

Topics: Bone Marrow; Busulfan; Diagnosis, Differential; Erythropoiesis; Granulocytes; Humans; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Osteosclerosis; Phosphorus Radioisotopes; Polycythemia; Polycythemia Vera; Primary Myelofibrosis; Thrombocythemia, Essential

Topics: Anemia, Aplastic; Animals; Bacteriological Techniques; Bone Marrow; Glomerular Filtration Rate; Histological Techniques; Humans; Hypersplenism; Immunologic Techniques; Iodine Radioisotopes; Kidney; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Muramidase; Neutrophils; Phosphorus Radioisotopes; Polycythemia Vera; Rabbits

Between 1980 and 1992, 237 polycythaemic patients aged 65 or more, or with high vascular risk factors were treated with 32P according to a protocol using, or not, maintenance therapy with low-dose hydroxy-urea (500 mg/day). The present follow-up covers 1448 years/patient. Maintenance therapy was seldom discontinued because of blood toxicity or gastrointestinal intolerance, but it was stopped in 20 percent of the cases because monitoring was difficult in very old patients. Maintenance therapy reduced the mean annual 32P dose by at least 50 percent. However, the actual risk of malignant blood diseases (myelodysplasia, acute leukaemia, lymphoma) was similar in the two arms of the protocol: 14 percent at the 10th year. Compared with the French population of the same age-groups, there was no excess of epithelial cancers in both arms. Maintenance therapy did not control platelet counts perfectly. The risk of severe vascular events was identical in both arms; probably no higher than expected at that age and significantly lower than in previously published data. The actuarial survival curves in both groups showed a 50 percent survival of about 11 years, i.e. very near to that of the reference French population (12.5 years) of similar sex and age.

Topics: Age Factors; Aged; Carcinoma; Cardiovascular Diseases; Female; Humans; Hydroxyurea; Injections, Intravenous; Leukemia, Myeloid, Acute; Male; Middle Aged; Myelodysplastic Syndromes; Phosphorus Radioisotopes; Polycythemia; Primary Myelofibrosis; Risk Factors

Patients with myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocythemia, and primary myelofibrosis, have a propensity to develop acute myeloid leukemia (AML) and myelodysplastic syndromes (MDSs). Using population-based data from Sweden, we assessed the role of MPN treatment and subsequent AML/MDS risk with special focus on the leukemogenic potential of hydroxyurea (HU).. On the basis of a nationwide MPN cohort (N = 11,039), we conducted a nested case-control study, including 162 patients (153 and nine with subsequent AML and MDS diagnosis, respectively) and 242 matched controls. We obtained clinical and MPN treatment data for all patients. Using logistic regression, we calculated odds ratios (ORs) as measures of AML/MDS risk.. Forty-one (25%) of 162 patients with MPNs with AML/MDS development were never exposed to alkylating agents, radioactive phosphorous (P(32)), or HU. Compared with patients with who were not exposed to HU, the ORs for 1 to 499 g, 500 to 999 g, more than 1,000 g of HU were 1.5 (95% CI, 0.6 to 2.4), 1.4 (95% CI, 0.6 to 3.4), and 1.3 (95% CI, 0.5 to 3.3), respectively, for AML/MDS development (not significant). Patients with MPNs who received P(32) greater than 1,000 MBq and alkylators greater than 1 g had a 4.6-fold (95% CI, 2.1 to 9.8; P = .002) and 3.4-fold (95% CI, 1.1 to 10.6; P = .015) increased risk of AML/MDS, respectively. Patients receiving two or more cytoreductive treatments had a 2.9-fold (95% CI, 1.4 to 5.9) increased risk of transformation.. The risk of AML/MDS development after MPN diagnosis was significantly associated with high exposures of P(32) and alkylators but not with HU treatment. Twenty-five percent of patients with MPNs who developed AML/MDS were not exposed to cytotoxic therapy, supporting a major role for nontreatment-related factors.

Topics: Adult; Aged; Antineoplastic Agents, Alkylating; Case-Control Studies; Female; Humans; Leukemia, Myeloid, Acute; Leukocyte Count; Logistic Models; Male; Middle Aged; Myelodysplastic Syndromes; Phosphorus Radioisotopes; Polycythemia Vera; Primary Myelofibrosis; Risk Factors; Thrombocythemia, Essential

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Busulfan; Female; Follow-Up Studies; Humans; Hydroxyurea; Leukemia, Myeloid, Acute; Leukemia, Myelomonocytic, Chronic; Male; Middle Aged; Myelodysplastic Syndromes; Neoplasms, Second Primary; Phosphorus Radioisotopes; Pipobroman; Retrospective Studies; Thrombocythemia, Essential

Serine phosphorylation of bcl-2 has been reported after treatment of cells with protein kinase C, okadaic acid, taxol, and other chemotherapeutic agents that attack microtubules. We report here that bcl-2 is phosphorylated on serine in acute myeloblastic leukemia (AML) blasts exposed to all trans retinoic acid (ATRA). Two-dimension gels (isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]) disclosed a novel acidic isoform of bcl-2 in ATRA-treated blast cells from a continuous line and from two AML patients; when the cell lysates were digested with lambda-phosphatase, bcl-2 reverted to the control position, indicating that it was phosphorylated. Metabolic labeling experiments using 32Pi showed that, while control bcl-2 was labeled, incorporation was greatly increased when cells were treated with ATRA. A comparison of bcl-2 from blasts treated with ATRA or taxol showed that bcl-2 was phosphorylated on serine in cells treated with either agent; however, both qualitative and quantitative differences were seen. Qualitatively, the phosphorylated isoform from taxol-treated cells was slightly larger than the native isoform and could be distinguished on 10% to 20% SDS-polyacrylamide gradient gels, while the phosphorylated bcl-2 after ATRA ran as a single band on gradient gels at the same position as control bcl-2. Quantitatively, all bcl-2 from ATRA-treated cells was in the phosphorylated isoform, while after taxol, both phosphorylated and native bcl-2 was present; incorporation of 32Pi into bcl-2 was stimulated to greater extent in ATRA-treated compared with taxol-treated cells. We used immunoprecipitation experiments to ask if bcl-2 phosphorylated after ATRA or taxol had altered capacity to dimerize with bax. No change in dimerization was demonstrated. We conclude that: bcl-2 is phosphorylated on serine after treatment of AML blasts with ATRA; bcl-2 phosphorylation after ATRA is different from that seen after taxol; bcl-2 phosphorylated after either agent retains capacity to dimerize with bax. The ATRA or taxol-induced phosphorylation of bcl-2 can also be seen in blast cells obtained from AML patients.

Topics: Dimerization; Electrophoresis, Gel, Two-Dimensional; Humans; Immunosorbent Techniques; Leukemia, Myeloid, Acute; Paclitaxel; Phosphoamino Acids; Phosphoric Monoester Hydrolases; Phosphorus Radioisotopes; Phosphorylation; Phosphoserine; Proto-Oncogene Proteins c-bcl-2; Recombinant Proteins; Tretinoin; Tumor Cells, Cultured

Topics: Administration, Oral; Aged; Female; Humans; Leukemia, Myeloid, Acute; Male; Phosphorus Radioisotopes; Polycythemia Vera; Risk Factors

For 366 patients with polycythaemia vera (PV) or essential thrombocythaemia (ET) diagnosed 1971-1990, oral administration of 32-P was used as myelosuppressive treatment. Retreatment was not restricted to any defined interval and the number of treatments or the total dose were not limited. For 107 patients, follow-up was > 10 years. 15 of these presented with life-threatening occlusive vascular symptoms and their survival was short. For the remaining 92 patients 5-yr survival was not significantly worse than for a Swedish population matched for age and sex. Survival at 10 yr was lower, 51% versus 66% expected. Acute myeloid leukaemia (AML) was diagnosed in 11 of the 107 patients (10.3%). In the whole material of 366 patients, 17 have developed AML with a median time of 8.5 yr from start of treatment. There was a maximum incidence of 4% per yr after 8-12 yr. Later, the incidence decreased. The median annual dose of 32-P for the AML patients was 100 MBq and was not significantly larger than for a matched control group surviving without AML, 96 MBq. The results are compared with reports on PV or ET patients treated with busulphan (Bu) or hydroxyurea (HU). With comparable periods of follow-up there are no indications that an adequate myelosuppression with oral 32-P will be associated with shorter survival or higher incidence of AML than treatment with Bu or HU. It is concluded that, for the time being, oral administration of 32-P is an acceptable standard treatment in PV and ET.

Topics: Administration, Oral; Aged; Busulfan; Female; Humans; Hydroxyurea; Leukemia, Myeloid, Acute; Leukemia, Radiation-Induced; Male; Neoplasms, Second Primary; Phosphorus Radioisotopes; Polycythemia Vera; Thrombocytosis; Time Factors

Immortal HL60 promyelocytes are induced to differentiate to mortal adherent cells by a variety of agents which activate protein kinase C, including 12-O-tetradecanoylphorbol 13-acetate (TPA). In order to investigate the mechanism of this effect, we incubated HL60 cells with [32P]orthophosphate with or without TPA and extracted their proteins with the cationic detergent benzyldimethyl-n-hexadecylammonium chloride prior to electrophoresis in a discontinuous polyacrylamide gel system in the first dimension. In this system, proteins migrate toward the cathode as a function of their molecular weight, and they are separated from other radioactive components which can obscure the pattern of protein phosphorylation on sodium dodecyl sulfate (SDS) gels. SDS gel electrophoresis was used in the second dimension, resulting in the clear resolution of a large number of proteins. TPA caused many changes in the pattern of protein phosphorylation in intact cells. Two proteins which prominently increased their incorporation of 32P were investigated in particular, and they were both found to be retained in the nuclear matrix following successive extraction of cells with Triton, digestion with DNase and RNase, and extraction with 2 M NaCl. These proteins migrated with apparent molecular weights of 80,000 and 33,000 on SDS gels, and are designated NP80 and NP33, respectively. NP80 was half-maximally phosphorylated after 7 min exposure to TPA, and half-maximally phosphorylated by 10 nM TPA. NP80 co-migrated with a faint Coomassie Blue-stained protein, and NP33 co-migrated with a more prominent protein. Several proteins incorporated less 32P when the cells were exposed to TPA, including one which was extracted from nuclei with the core histones and which co-migrated with histone H2A. Further study will be needed to determine whether the differentiation of HL60 induced by TPA is mediated via phosphorylation of these nuclear matrix proteins.

Topics: Antigens, Nuclear; Autoantibodies; Autoradiography; Cell Adhesion; Cell Line; Electrophoresis, Polyacrylamide Gel; Humans; Kinetics; Leukemia, Myeloid, Acute; Nucleoproteins; Phorbols; Phosphorus Radioisotopes; Phosphorylation; Tetradecanoylphorbol Acetate

A phosphate-incorporating protein has been highly purified from the cytosol of Ehrlich ascites tumor cells (EAT cells). The nitrocellulose membrane method was used to follow the progress of the purification by quantitation of the [32P]phosphorylated form of the protein. The purified protein was identified as an NDP-kinase since it exhibited NDP-kinase activity and had enzyme characteristics in common with other NDP-kinases from various mammalian cells. The purified NDP-kinase was found to have a molecular weight of approximately 76,000 daltons. Moreover, the enzyme appears to consist of two distinct polypeptides (18,000 and 20,000 daltons). This enzyme contained 19 amino acids, with high levels of glycine (9.8%) and lysine (9.0%). The enzyme rapidly formed a [32P]phosphoenzyme when incubated with [gamma-32P]ATP in the presence of Mg2+ (1 mM) at the optimum pH of 7.5 even at low temperature (below 4 degrees C). This phosphoenzyme is an enzyme-bound, high-energy-phosphate intermediate, because ATP was formed from it on incubation with ADP in the presence of Mg2+ (1 mM). This finding suggests that the phosphoenzyme functions as an intermediate in NDP-kinase action.

Topics: Amino Acids; Animals; Carcinoma, Ehrlich Tumor; Cell Line; Cytosol; HeLa Cells; Humans; Hydrogen-Ion Concentration; Kinetics; Leukemia, Myeloid, Acute; Macromolecular Substances; Mice; Molecular Weight; Nucleoside-Diphosphate Kinase; Phosphorus Radioisotopes; Phosphorylation; Phosphotransferases; Ribonucleotides

Treatment of the promyelocytic leukemic cells, HL-60, with phorbol-12-myristate-13-acetate (PMA) results in arrest of growth and terminal differentiation of the cells into macrophages. We have reported that within minutes following exposure of these cells to PMA there is an increase of severalfold in phosphorylation of two cytosol proteins: 17-20 kDa (pp17, pI approximately 5.5) and 27 kDa (pp27, pI approximately 5.5) as detected in the intact cells by two-dimensional gel electrophoresis. In this report, by analyzing the chase kinetics of 32Pi in cellular proteins, we show that PMA treatment induces a rapid and specific loss of 32Pi from pp17 and pp27. Comparison with kinetics of [3H]leucine loss from these proteins indicates that this effect is due to induction by PMA of rapid turnover of phosphate in pp17 and pp27. This activity persisted in HL-60 for at least 24 h and was also seen in two other cell types studied (U937 leukemia and normal monocytes). The Ca2+ channel blocker, nifedipine, had no effect on PMA-induced 32Pi turnover in pp17, while trifluoroperazine, which is known to inhibit protein kinase C, blocked these events and also inhibited other cellular effects of PMA (adherence and growth arrest). Thus, induction of rapid 32Pi turnover in pp17 and pp27 may be an essential early signal in initiating and maintaining cellular effects of PMA. Myosin light chain (20 kDa), another phosphorylated protein, was shown to be not identical with pp17, although of similar Mr.

Topics: Cell Line; Electrophoresis, Polyacrylamide Gel; Humans; Kinetics; Leukemia, Myeloid, Acute; Molecular Weight; Monocytes; Neoplasm Proteins; Phorbols; Phosphoproteins; Phosphorus Radioisotopes; Phosphorylation; Tetradecanoylphorbol Acetate

14 patients with essential thrombocythemia (ET) and 1 patient with agnogenic myeloid metaplasia received (1-(2-chloroethyl)-cyclohexyl-nitrosourea (CCNU), 80 mg/m2, p.o., in a single dose once a month up to three times. Remission was achieved in 13 patients (86.6%) and easily maintained by low-dose busulfan (2 mg twice a week). The data on the treatment of ET reported in the literature have been reviewed and compared to our results.

Topics: Adult; Age Factors; Aged; Alkylating Agents; Busulfan; Female; Humans; Leukemia, Myeloid, Acute; Lomustine; Male; Middle Aged; Nitrosourea Compounds; Phosphorus Radioisotopes; Primary Myelofibrosis; Thrombocytosis

Topics: Aged; Humans; Leukemia, Myeloid, Acute; Male; Phosphorus Radioisotopes; Thrombocythemia, Essential

Topics: Aged; Female; Humans; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukemia, Radiation-Induced; Male; Middle Aged; Phosphorus Radioisotopes; Polycythemia Vera

Topics: Acute Disease; Cell Nucleolus; Humans; Lectins; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Leukocytes; Lymphocytes; Lymphoma, Non-Hodgkin; Phosphorus Radioisotopes; RNA, Neoplasm; RNA, Ribosomal

Topics: Base Sequence; Burkitt Lymphoma; Cell Line; Cells, Cultured; Centrifugation, Density Gradient; Chromatography, DEAE-Cellulose; Genes; Humans; Lectins; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Lymphocyte Activation; Lymphocytes; Oligonucleotides; Pancreas; Phosphorus Radioisotopes; Purines; Remission, Spontaneous; Ribonucleases; RNA, Ribosomal

Topics: Cell Nucleus; Centrifugation, Density Gradient; Cytoplasm; Humans; Lectins; Leukemia, Myeloid, Acute; Lymphocytes; Nucleotides; Phosphorus Radioisotopes; RNA, Neoplasm; RNA, Ribosomal; Stimulation, Chemical

Topics: Burkitt Lymphoma; Cell Nucleus; Centrifugation, Density Gradient; Humans; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Lymphoma, Non-Hodgkin; Phosphorus Radioisotopes; RNA, Neoplasm; Sucrose