tretinoin and Leukemia--Myelomonocytic--Chronic

Used as single agents, ATRA, G-CSF, and IFN-alpha have shown a moderate benefit in patients with low-risk MDS, with a response rate of 10%. The aim of the present study was to evaluate the efficacy of a combination of these agents. The effect on hemoglobin (Hb), platelets, and absolute neutrophil count (ANC), as well as on transfusion frequency, was examined in 25 patients with MDS (11 RA, four RARS, eight RAEB, two CMML). The median age was 61 years (range 44-81), and the male/female ratio was 14/11. Treatment consisted of ATRA at 25 mg/m2/day p.o. for months 1, 3, 5, 7, 9, and 11, IFN-alpha at 1.5 MIU twice a week s.c. for 52 weeks, and, in patients with initial ANC <500/microl, G-CSF at 100-480 microg daily s.c. according to the degree of ANC. The duration of therapy was scheduled for 12 months. Two patients achieved ongoing CR (+19 months; +16 months), one patient with RA after 3 months and one with CMML after 7 months of treatment. In all patients, the mean ANC increased significantly from 1400+/-200/microl before the start of therapy to 3500+/-600/microl at the end of treatment (p=0.025). In two patients an increase of Hb was observed, and one patient ceased to require transfusions. In an additional patient with RA and 5q-syndrome, the platelet count normalized following administration of ATRA/IFN-alpha, increasing from 89,000/microl to 293,000/microl. The eight RAEB patients were nonresponders. We conclude that therapy with ATRA, IFNalpha, and G-CSF is effective in approximately 35% of low-risk MDS patients (in this study: six of 17) and may induce complete remission in individual cases.

Topics: Adult; Aged; Aged, 80 and over; Anemia, Refractory; Anemia, Refractory, with Excess of Blasts; Drug Therapy, Combination; Female; Granulocyte Colony-Stimulating Factor; Humans; Interferon-alpha; Leukemia, Myelomonocytic, Chronic; Leukocyte Count; Male; Middle Aged; Myelodysplastic Syndromes; Neutrophils; Remission Induction; Tretinoin

Retinoids can inhibit the spontaneous in vitro growth of CFU-GM observed in juvenile chronic myeloid leukemia (JCML) and, when administered in vivo, have shown some clinical benefit in this disease. Because adult chronic myelomonocytic leukemia (CMML) has many features in common with JCML, we treated 10 cases of advanced adult CMML with ATRA (45 mg/m2/day). Five of them were also tested in vitro. After two patients had a rapid increase in WBC counts and clinical signs reminiscent of the 'ATRA syndrome' seen in acute promyelocytic leukemia, with fatal outcome in one of them, it was decided to add hydroxyurea (HY) to ATRA to patients with high WBC at inclusion or during ATRA treatment, and no more cases of ATRA syndrome were seen. Overall, six patients received ATRA + HY and four ATRA alone. Four patients had a minor but significant response with reduction of transfusion requirement (two cases) or increase in platelet counts (two cases). Apart from the ATRA syndrome, no other side-effect of ATRA was seen. Bone marrow mononuclear cells showed spontaneous growth of CFU-C in methylcellulose in the five patients tested in vitro, with a predominance of CFU-M. ATRA (10(-7) M) inhibited CFU-M growth in all cases, but increased CFU-G growth in one patient who developed the ATRA syndrome. No differentiation of bone marrow myeloid cells after short-term liquid culture with ATRA was observed. A decrease of CFU-C growth was observed in the four patients reevaluated during follow-up. In some cases of CMML, ATRA can improve anemia or thrombocytopenia but not other parameters. Furthermore, it can also induce hyperleukocytosis and ATRA syndrome in some patients, requiring the rapid addition of cytoreductive agents such as HY.

Topics: Aged; Antineoplastic Agents; Bone Marrow; Colony-Forming Units Assay; Female; Hematopoietic Stem Cells; Humans; Hydroxyurea; Leukemia, Myelomonocytic, Chronic; Leukocytosis; Male; Middle Aged; Pilot Projects; Platelet Count; Syndrome; Tretinoin; Tumor Cells, Cultured

Topics: Cell Differentiation; Humans; Leukemia, Myelomonocytic, Chronic; Leukemia, Promyelocytic, Acute; Retinoids; Tretinoin

All trans retinoic acid, the active metabolite of vitamin A, exerts profound effects on cell differentiation. On normal myeloid progenitors, retinoids switch the differentiation program of granulo-macrophagic progenitors towards the granulocytic lineage and consequently reduce CFU-M colony formation. Bone marrow and peripheral blood mononuclear cells from children with Juvenile Chronic Myelomonocytic Leukaemia show typical spontaneous monocytic growth. We questioned whether in this disease, retinoids could switch myelomonocytic growth and inhibit the abnormal CFU-M colony proliferation.. Ten JCML samples were studied in the presence of ATRA in methyl cellulose colony assay, before (CFU-C) or after (pre-CFU) liquid suspension culture.. In vitro characteristics of JCML such as spontaneous monocytic growth in the absence of growth factor was noted in all patients. In the presence of leucocyte-conditioned medium, nine samples showed only CFU-M growth and one sample CFU-GM growth. Incubation with ATRA inhibited CFU-M colony formation in nine cases. Enhancement of granulocytic differentiation (CFU-G) was noted in nine cases. ATRA also inhibited CD34+ JCML monocytic growth and GM-CSF hypersensitivity.. These data suggest that, in JCML progenitors, retinoid pathways are functional and inhibition of immature monocytic progenitors cells may be achieved with retinoids, without impeding granulocytic cell growth.

Topics: Antineoplastic Agents; Cell Differentiation; Cell Proliferation; Child; Female; Granulocyte Precursor Cells; Humans; Leukemia, Myelomonocytic, Chronic; Male; Tretinoin; Tumor Cells, Cultured

When bcl-2 is immunoprecipitated from (32)P-labeled cell extracts of all-trans retinoic acid (ATRA)-treated acute myeloblastic leukemia (AML) blasts, a phosphorylated protein of approximately 30 kd is coprecipitated. This protein has been identified as ribosomal protein S3a. The biologic effects of S3a include favoring apoptosis and enhancing the malignant phenotype. We sought to determine whether S3a, like bcl-2, influenced the response of cells to chemotherapeutic drugs and ATRA. Cell lines were studied in which S3a was genetically increased or disrupted; increased S3a was regularly associated with increased plating efficiency and increased sensitivity to either cytosine arabinoside (ara-C) or doxorubicin (DNR). S3a did not affect the sensitivity of cells to paclitaxel. Pulse exposures to either (3)HTdR or ara-C showed a greater percentage of clonogenic cells in the S phase of the cell cycle in cells with increased S3a than in controls. Cells with increased S3a responded to ATRA by increased ara-C or DNR sensitivity, whereas cells with reduced S3a protein were either protected by ATRA or not affected. We studied cryopreserved blast cells from patients with AML or chronic myelomonocytic leukemia (CMML). S3a protein levels were heterogeneous in these populations. In 32 cryopreserved blast populations, S3a levels were significantly correlated with both bcl-2 and with cell growth in culture. As in cell lines, high S3a in cryopreserved blasts was associated with ATRA-induced sensitization to ara-C. No significant association was seen between S3a levels and response to treatment.

Topics: Animals; Antibiotics, Antineoplastic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line; Cryopreservation; Cytarabine; DNA Replication; DNA, Neoplasm; Doxorubicin; Drug Resistance, Neoplasm; Gene Targeting; Humans; Leukemia, Myeloid, Acute; Leukemia, Myelomonocytic, Chronic; Neoplasm Proteins; Neoplastic Stem Cells; Paclitaxel; Phosphorylation; Phosphoserine; Protein Processing, Post-Translational; Rats; Ribosomal Proteins; Tissue Preservation; Treatment Outcome; Tretinoin

We recently synthesized several conformationally constrained retinoic acid (RA) analogues [8-(2'-cyclohexen-1'-ylidene)-3, 7-dimethyl-2,4,6-octatrienoic acids with different alkyl substituents at 2' (R1) and 3' (R2) positions on the cyclohexene ring] (Muccio et al. J. Med. Chem. 1996, 39, 3625) as cancer chemopreventive agents. UAB8 (R1 = Et; R2 = iPr), which contains sufficient steric bulk at the terminal end of the polyene chain to mimic the trimethylcyclohexenyl ring of RA, displayed biological properties similar to those of RA. To explore the efficacy of this retinoid in acute promyelocytic leukemia (APL) and juvenile myelomonocytic leukemia (JMML), we evaluated UAB8 isomers in in vitro assays which measure the capacity of retinoids to inhibit aberrant myeloid colony growth from blood or bone marrow cells obtained from human JMML patients and in assays measuring the potential of retinoids to differentiate NB4 cells (an APL cell line). Both (all-E)- and (13Z)-UAB8 were 2-fold more active than RA in the NB4 cell differentiation assay; however, only (all-E)-UAB8 had comparable activity to the natural retinoids in the JMML cell assays. These results were compared to the biological effectiveness of a new retinoid, UAB30 [8-(3', 4'-dihydro-1'(2'H)-naphthalen-1'-ylidene)-3,7-dimethyl-2,4, 6-octatrienoic acid], which had different nuclear receptor binding and transactivational properties than UAB8. Relative to (all-E)-RA and (all-E)-UAB8, (all-E)-UAB30 bound well to RARalpha but did not activate transcription-mediated RARalpha homodimers, even though it was effective in RARbeta- and RARgamma-mediated transactivational assays. In APL assays, this retinoid had much reduced activity and was only moderately effective in JMML assays and in cancer chemoprevention assays.

Topics: Animals; Antineoplastic Agents; Cell Line; Chickens; Child; Fatty Acids, Unsaturated; HL-60 Cells; Humans; In Vitro Techniques; Leukemia, Myelomonocytic, Chronic; Leukemia, Promyelocytic, Acute; Mice; Molecular Conformation; Naphthalenes; Papilloma; Radioligand Assay; Receptors, Retinoic Acid; Skin; Skin Neoplasms; Stereoisomerism; Transcription, Genetic; Tretinoin; Tumor Stem Cell Assay

Myelodysplastic syndrome (MDS)-derived leukemia cell line P39/Tsugane could be induced to apoptosis by a variety of agents including metabolic inhibitors, a calcium ionophore and differentiation-inducing agents. As evaluated by characteristic morphological changes and oligonucleosomal lengths DNA ladder, the levels of apoptosis in P39 cells induced by actinomycin D, or A23187, were far greater than in other myeloid lines examined in this study. When 22-oxa-1 alpha, 25(OH)2D3 (D3), dimethyl sulfoxide (DMSO) and all-trans retinoic acid (RA) were used as differentiation-inducers, varying degrees of apoptosis were seen. D3 induced monocytoid differentiation, but not apoptosis above the control level. On the other hand, RA induced profound apoptosis concomitant with the progressive expression of differentiation markers. Studies on morphology, functions and phenotypes of P39 cells exposed to differentiation inducers suggest that the incidence of apoptosis was not affected by the process of differentiation, but cells in the process of varying degrees of differentiation may die via apoptosis. Moreover, RA-treated P39 cells are unique in the simultaneous occurrence of profound apoptosis and differentiation. We propose that RA-treated P39 differentiation model is ideally suited for the study of MDS.

Topics: Apoptosis; Calcimycin; Cell Differentiation; Dactinomycin; Dimethyl Sulfoxide; Humans; Leukemia, Myeloid; Leukemia, Myelomonocytic, Chronic; Tretinoin; Tumor Cells, Cultured

Topoisomerase II has been suggested to have a role in the early events of differentiation. This possibility was evaluated by measuring the effects of inhibitors of topoisomerase II on the induction of the differentiation of WEHI-3B D+ monomyelocytic leukemia cells. Differentiation of this cell line was induced along the granulocytic pathway by treatment with the topoisomerase II inhibitors novobiocin (150-300 microM), teniposide (20-50 nM), etoposide (0.1 microM), elsamicin (0.5 microM), and doxorubicin (40 nM). Maturation was assessed by the morphological appearance of mature forms of the granulocytic lineage, an increase in cell surface Fc receptors, the ability to reduce nitroblue tetrazolium, and the loss of proliferative capacity. In contrast, the non-topoisomerase II-reactive agent cisplatin and the topoisomerase I-reactive drug camptothecin did not cause the maturation of WEHI-3B D+ cells. Aclacinomycin A and retinoic acid, which are known efficacious inducers of the differentiation of this cell line, affected topoisomerase II extracted from WEHI-3B D+ cells in vitro, causing concentration-dependent inhibition of the strand-passing activity of the enzyme. Treatment of WEHI-3B D+ cells with novobiocin at 150 microM for 3 h or with teniposide at 50 nM for 24 h resulted in a 2- to 3-fold increase in etoposide-induced protein-DNA cross-links. Nuclear proteins in 0.35 M NaCl extracts from cells treated with novobiocin at 150 microM for 3 h or with teniposide at 50 nM for 24 h showed a slight increase in topoisomerase II activity compared to untreated cells. No changes in topoisomerase II levels, as measured by immunoblotting, were detected after treatment of WEHI-3B D+ cells with 150 microM novobiocin or 50 nM teniposide during the first 2 days of treatment. At day 3 of treatment, however, a decrease in topoisomerase II was observed in cells treated with either drug, possibly due to decreased cellular proliferation consequent to cell differentiation. The findings support the conclusion that topoisomerase II may have a role in the induction of granulocytic differentiation of WEHI-3B D+ leukemia cells.

Topics: Aclarubicin; Animals; Cell Cycle; Cell Differentiation; Doxorubicin; Leukemia, Myelomonocytic, Chronic; Mice; Novobiocin; Teniposide; Topoisomerase II Inhibitors; Tretinoin; Tumor Cells, Cultured