Recombinant human granulocyte-macrophage colony-stimulating factor induces secretion of autoinhibitory monokines by U-937 cells

Colony-stimulating factors are required for survival proliferation, differentiation and functional activation of granulocytes, macrophages and their precursor cells. In the present report, however, we demonstrate antiproliferative activity of recombinant human (rh) granulocyte-macrophage colony-stimulating factor (GM-CSF) on monoblast cell line U-937 and provide evidence for the involvement of tumor necrosis factor alpha TNF-alpha and interleukin 1 beta (IL 1 beta) in its growth inhibitory action. GM-CSF (but not granulocyte CSF, G-CSF or macrophage CSF, M-CSF) suppressed DNA synthesis and self renewal of U-937 cells. Similarly, medium conditioned by U-937 cells in response to GM-CSF (GM-CSF U-937-CM) was able to reduce clonogenicity and [3H]thymidine uptake by U-937 cells. Since neutralization of GM-CSF present in GM-CSF U-937-CM by monoclonal antibody to GM-CSF did not abrogate the autoinhibitory activity present in GM-CSF U-937-CM, we considered the possibility that other soluble molecules are released by U-937 cells upon GM-CSF stimulation. Neutralization by antibodies to IL 1 beta and TNF-alpha suggested that both monokines could be the antiproliferative principle operating in GM-CSF U-937-CM. Moreover, employing IL 1 beta-specific enzyme-linked immunosorbent assay, TNF-alpha specific radioimmunoassay, Northern analysis using a cloned TNF-alpha-specific cDNA and an oligonucleotide probe for IL 1 beta, we demonstrate GM-CSF-inducible IL 1 beta and TNF-alpha gene expression by U-937 cells at the mRNA and protein level. Although M-CSF expression was induced under similar conditions, M-CSF failed to inhibit growth of U-937 cells.     

Peripheral blood progenitor cells mobilized by chemotherapy plus granulocyte-colony stimulating factor accelerate both neutrophil and platelet recovery after high-dose VP16, ifosfamide and cisplatin

Summary. We report on the chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPCs) and their impact on haematopoietic recovery following high-dose chemotherapy. Twenty-four patients with advanced solid tumours or lymphomas received standard-dose chemotherapy with VP16, ifosfamide and cisplatin (VIP) followed by filgrastim (G-CSF; 5 μg/kg s.c. daily for 14 d) for the prevention of chemotherapy induced neutropenia and for the simultaneous mobilization of PBPCs. Maximal numbers of progenitors of different lineages were reached at day 11 (range 9–14) after VIP chemotherapy. A median of 0·415 × 10⁹/1 CD34⁺ cells (range 0·11–1·98), 9000 CFU-GM/ml (range 2800–17700). 3500 BFU-E/ml (range 400–10800) and 200 CFU-GEMM/ml (range 0–4400) were recruited. One single apheresis yielded a median of 1·6 × 10⁸ mononuclear cells/kg (range 0·2–5·4) or 5·4 × 10⁶ CD34⁺ cells/kg body weight (range 0·2–24·2). Fourteen patients who showed at least a partial remission after two cycles of the standard-dose chemotherapy regimen were subjected to high-dose VIP chemotherapy (cumulative doses of 1500 mg/m² VP16, 12 g/m² ifosfamide and 150 mg/m² cisplatin) with or without PBPC support. The first six patients were treated with growth factors only (IL-3/GM-CSF) and did not receive PBPCs, whereas the following eight patients were supported with PBPCs in addition to IL-3 and GM-CSF. Neutrophil recovery as well as platelet recovery were significantly faster in patients receiving PBPCs with a median of 6·5 d below 0·1 × 10⁹ neutrophils/1 and 3 d below 20 × 10⁹ platelets/1 as compared to 10·5 d and 8 d in control patients receiving growth factors only. The accelerated platelet recovery in patients supported with PBPCs might be explained—in the absence of detectable colony-forming units megakaryocyte—by the presence of glycoprotein IIb/IIIa⁺, non-proliferating endomitotic megakaryocytic precursor cells within G-CSF mobilized PBPCs. Our data demonstrate that chemotherapy plus G-CSF mobilized PBPCs accelerate both neutrophil and platelet recovery after high-dose VIP chemotherapy in patients with solid tumours or lymphomas.     

Current status of treatment of acute leukemia in adults: an overview of the Memorial experience and review of literature

The results of treatment of 629 previously untreated adults with acute leukemia at Memorial Hospital are reviewed. During the past 14 years, 135 adults (greater than 15 years) with acute lymphoblastic leukemia (ALL) have been treated with one of three successive multidrug-intensive treatment protocols (L2, L10/10M, and L17/17M), each calling for 2.5 to 3 years of systemic chemotherapy and prophylactic intrathecal methotrexate without cranial irradiation. The complete remission (CR) rates were L2 (n = 22) = 77%; L10/10M (n = 69) = 86%; L17/17M (n = 44) = 77%. The median durations of survival and remission were, respectively, L2 = 33 and 30 months; L10/10M = 62 months and not reached; and L17/17M = not reached. Almost all relapses occurred within the first 3 years while still continuing treatment, and there were only rate late relapses after stopping treatment. It appears that approximately half of the patients may have been cured with the latest two protocols. During the last 17 years, 494 adults aged 15 to greater than 70 with acute nonlymphoblastic leukemia (ANLL) were treated with one of five successive multiple drug treatment protocols of varying intensity (arabinosylcytosine + 6-thioguanine [n = 36]; L6 [n = 101]; L12 [n = 104]; L14/14M [n = 121]; and L16/16M [n = 132]). Patients with myelodysplastic syndromes generally were not treated until they developed acute leukemia, but were then entered and included in the results. Secondary leukemias following treatment of other neoplastic diseases were not included. The complete remission rates were fairly constant between 47 and 64% and the median durations of remissions were between 9 and 21 months. The intensive treatment L14 and L16 protocols were associated with more early deaths and did not result in a significantly improved remission incidence or duration or survival. With all protocols, the majority of relapses occurred within the first 2 years, but relapses continued to occur at a decreasing rate for 4 years and occasionally even later. Whereas a small fraction (approximately 10 to 15%) of adults with ANLL are now apparently being cured with combination chemotherapy, despite intensive efforts there has been little improvement during the last decade and more selective and effective forms of treatment are urgently needed.     

High-dose cytosine arabinoside and mitoxantrone: a highly effective regimen in refractory acute myeloid leukemia

In a clinical phase I/II study, high-dose cytosine arabinoside and mitoxantrone (HAM) were given in combination to 40 patients with refractory acute myeloid leukemia. All patients had received a 9-day combination of thioguanine, Ara-C, and daunorubicin (TAD-9) as standardized first-line treatment. Refractoriness was defined as (a) nonresponse against two TAD-9 induction cycles, (b) early relapse within the first 6 months on monthly maintenance or after TAD-9 consolidation, (c) relapse after 6 months with nonresponse against one additional TAD-9 cycle, and (d) second and subsequent relapses after successful TAD-9 therapy at the preceding relapse. Therapy consisted of HD-Ara-C 3 g/m2 every 12 hours on days 1 through 4; mitoxantrone was started at 12 mg/m2/day on days 3, 4, and 5 and was escalated to 4 and 5 doses of 10 mg/m2/day on days 2 through 5 and 2 through 6. Of the 40 patients, 21 achieved a complete remission (53%), 1 patient had a partial remission, and 5 patients were nonresponders. Thirteen patients died in aplasia due to infections (n = 11), pericardiac effusion, or acute cardiomyopathy. Nonhematologic side effects consisted predominantly of nausea and vomiting, mucositis, and diarrhea. Central nervous system (CNS) symptoms were observed during six treatment courses. Recovery of blood counts occurred at a median of 27 days from the onset of treatment; the median time to complete remission was 36 days. Two of the 21 responders underwent successful bone marrow transplantations. The median remission duration for the remaining 19 patients is 4.5 months, and the median survival time is 9 months. These data emphasize that HAM has high antileukemic activity in refractory AML and strongly suggest starting the combination at earlier stages in AML therapy.     

Control of blast cell proliferation and differentiation in acute myelogenous leukemia by soluble polypeptide growth factors

Proliferation of acute myelogenous leukemia (AML) derived blast cells requires the presence in culture of one or more growth factors. In the majority of cases Interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulate clonogenicity of AML blasts, which can be synergised by Interleukin-6 (IL-6), Interleukin-1 (IL-1) and granulocyte colony-stimulating factor (G-CSF). In contrast, macrophage colony-stimulating factor (M-CSF) favors deterministic divisions. A substantial part of AML samples have clonogenic cells which, however, proliferate autonomously in vitro. The production by leukemic cells of a variety of growth or synergizing factors including GM-CSF, G-CSF, IL-1, IL-6, and Tumor Necrosis Factor (TNF) has been demonstrated and a fraction of cases will use these molecules to support clonogenic growth in an autocrine or paracrine fashion. However, unlike the situation with retrovirus-induced murine or avian leukemias, the role of production of CSFs and other cytokines by human leukemic cells in the transformational process remains uncertain.     

Relationship of Auer rods and chromosome findings to outcome in eighty-nine adults with acute nonlymphoblastic leukemia

We performed cytogenetic analyses using banding techniques on 89 adults with acute nonlymphoblastic leukemia prior to receiving protocol chemotherapy. The relationships of cytogenetic findings both to outcome and to other pretreatment variables (particularly the presence or absence of Auer rods) were analyzed. Patients were followed up to 90+ months. When patients were grouped according to cytogenetic findings (NN: all normal metaphases; AA: all abnormal metaphases; AN: both normal and abnormal metaphases; F: no evaluable metaphases; I: insufficient (less than three) metaphases) no significant differences were noted with regard to age, sex, terminal transferase positivity, complete remission rate, remission duration or survival. The marrow aspirates of patients with only normal (69%) metaphases or no evaluable metaphases (64%) were more likely to display Auer rods than specimens from individuals with only abnormal (26%) or a mixture of normal and abnormal (42%) metaphases (p = 0.03). The presence of Auer rods in the pretreatment marrow aspirate was associated with an increased complete remission rate (71% vs 41%, p = 0.004), median remission duration (12 months vs 9 months, p = 0.02), and median survival (13 months vs 4 months, p = 0.01). Using multivariable analyses, the presence or absence of Auer rods was the pretreatment factor that most significantly predicted response and survival in this group of patients. The presence of a normal karyotype in the initial cytogenetic preparation is associated with the presence of Auer rods. The finding of Auer rods in the initial bone marrow predicts greater response and longer survival in acute nonlymphoblastic leukemia.     

Interleukin 2: a review

Interleukin 2 (IL 2) is a central mediator of the growth and functional activity of B- and T-cells, and cytotoxic cells, including Natural Killer and Lymphokine Activated Killer cells. Significant defects in the production of, and response to, IL 2 have been described in a variety of congenital and acquired immunodeficiency states. IL 2 has demonstrated major anti-tumor activity in animal models. The biochemistry and molecular biology of IL 2 and its gene are reviewed, along with data regarding the IL 2 receptor, normal T-cell activation, abnormalities in IL 2 production and response in immunodeficiency states and leukemia, and initial explorations of IL 2 in the treatment of human cancer.