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Uncontrolled proliferation of acute myeloid leukemia (AML) cells is an important step during leukemogenesis. However, little is known about the mechanisms leading to growth autonomy. Studies using immortalized murine hematopoietic cell lines have suggested that autocrine production of growth factors, or the constitutive activation of molecules in growth factor signalling pathways, are involved. We have established six spontaneous factor-independent cell lines from the human growth factor-dependent TF-1 cell line. The factor-independent cells showed no detectable growth factor activity. Immunoblotting analyses of tyrosine phosphorylation, Raf-1 and extracellular signal-regulated kinase 2 (ERK-2) showed a similar pattern in all the cell lines including TF-1 cells. Furthermore, somatic-cell hybrids between TF-1 and the factor-independent cells grew in absence of growth factor. Taken together this data demonstrates that the factor independence in this system is dominant and suggests that the molecular event is located either downstream of the Raf-1 and MAP kinases pathway or on an alternative pathway. Finally, the karyotype analysis of one factor-independent cell line TF-1i1 and TF-1H- (G418 resistant, HAT sensitive TF-1 cells) and their hybrids demonstrated an unstable derivative chromosome [der(19) t(19;?) (q13.1;?)] which seemed to correlate with the factor-independence capacity. This model may help in our understanding of autonomous proliferation by human myeloid leukemias.

CD40 is a surface glycoprotein, member of the nerve growth factor receptor family, which is expressed on B cells and plays an important role in their development, growth, and differentiation. Using chromosomal in situ hybridization, we localized the CD40 gene to the long arm of chromosome 20, bands q12-q13.2. This localization correlates well with the mapping of the murine CD40 gene to the distal region of chromosome 2, syntenic to the human 20q11-q13 region.

Colony stimulating factors and especially rHuG-GSF, the first available neutrophil growth factor, have led to considerable interest in the field of stem cell transplantation because of their ability to induce stem cell peripheralization either alone or in association with high-dose chemotherapy. Few data exist, however, on the impact of rHuG-CSF on large scale bone marrow collection and autologous bone marrow transplantation (ABMT). This phase I, non-randomized, dose escalation study of rHu-G-CSF (lenograstim) administered to 30 patients at doses ranging from 1 to 40 micrograms/kg/day for 5 days before bone marrow harvesting showed that priming with rHu-G-CSF in vivo increased the number of bone marrow cells and D14 myeloid restricted progenitors (CFU-GM) and led to a better neutrophil recovery after ABMT compared with a contemporary unprimed control population. Otherwise, this study established that 5 days of rHuG-CSF therapy, as a sole stimulus, induced a tenfold increase in the circulating CFU-GM amongst which immature progenitors, estimated by the Delta assay (secondary CFU-GM grown after 7 days of liquid culture/primary CFU-GM), are detected. These conclusions were valid for doses as low as 2 micrograms/kg/day which induced only mild neutrophilia up to the highest dose (40 micrograms/kg/day) and suggest that a short course of rHuG-CSF is beneficial in increasing the stem cell collection.

The authors report two patients with large granular lymphocyte (LGL) expansion associated with rheumatoid arthritis corresponding to pseudo Felty's syndrome. These cells have natural killer and T cell surface antigen markers. LGL are a heterogeneous population and expansion of these cells is responsible for leukemia, which is generally a monoclonal proliferation. It has been suggested that Epstein-Barr virus (EBV) is a putative agent in this leukemia. No EBV DNA was found with a polymerase chain reaction analysis in the lymphocyte DNA of our two patients. Some cases of pseudo Felty's syndrome have exhibited a monoclonal pattern on Southern blot analysis of the T cell receptor. On the contrary, our two cases showed a polyclonal pattern with TCR beta chain Southern blot analysis. This fact, associated with the mild course seen in both over more than twenty years, suggest that pseudo Felty's syndrome is a disease with a good prognosis.

Acute myeloid leukemia (AML) cells are dependent for their survival and proliferation on hematopoietic growth factors. As tumor necrosis factor alpha (TNF alpha) can increase the proliferation of primary cultures of AML cells, we have investigated the effect of TNF alpha on the autocrine and/or paracrine growth control by one of the major AML growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF). First, a panel of AML cells were analysed with respect to their proliferative response to TNF alpha. We provide experimental evidence that TNF alpha induces both GM-CSF gene expression and up-regulation of high-affinity GM-CSF membrane receptor in TNF alpha-responsive cells. This effect is not restricted to the malignant phenotype, although it could account for the selective growth advantage of the leukemic clone over the normal cells upon TNF alpha stimulation.

Haematopoietic growth factors are a family of genetically determined low molecular weight glycoproteins which regulate the proliferation and differentiation of haemopoietic cells through specific membrane receptors. GCSF and GMCSF reduce the morbidity from infections associated with the neutropenia induced by chemotherapy of onco-haematological neoplasia; EPQ totally corrects not only the anaemia of patients with chronic renal failure, but also 50 percent of anaemias related to chemotherapy; finally, the activity of IL 3 on platelet production seems to control the thrombocytopenia which restricts the use of therapeutics.

The identification and purification of haemopoietic growth regulators have resulted in a better understanding of control mechanisms. Cloning and expression of the corresponding genes have shown that most of the activities observed correspond to specific glycoproteins produced by cells from numerous tissues, including those of bone marrow stroma and immune system. These cytokines activate the responsive cells through specific receptors expressed on their membranes. They exert an accurate control of haematopoiesis in a network of synergistic and antagonistic factors. The exact identification of their biological activities, together with the possibility of producing them in large amounts by genetic recombination, have already resulted in their therapeutic use with, in certain cases, a remarkable efficiency.

Twelve HIV-positive patients who either underwent or seroconverted after bone marrow transplantation (BMT) at the University of Marseille between 1981 and 1985 were reviewed in order to observe their rates of development of AIDS. Two patients were HIV positive prior to transplantation, while ten seroconverted after transplantation. Six patients underwent autologous BMT and six underwent allogeneic BMT; all of their respective donors were seronegative. Eleven patients developed AIDS (92%), with a mean AIDS-free time (AFT) of 1 year 8 months after BMT. Seven of those subjects died, with a mean survival over a 5-year follow-up period of 2.14 years after BMT. Five autologous recipients had a mean AFT of 2 years 3 months, with the sixth patient being AIDS free. The mean AFT for the allogeneic recipients was 1 year 2 months (p = NS), all of whom developed AIDS. These data suggest that the development of AIDS was rapid from the time when our patients seroconverted. However, this was not initially accompanied by poor survival. In summary, BMT may be indicated for HIV-positive patients who required myeloablation, despite an enhanced development of AIDS.

The expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene is differentially regulated in various cell types. We investigated the mechanisms controlling its expression in 12-O-tetradecanoylphorbol-13-acetate plus phytohemagglutinin-stimulated Jurkat cells, a human T-cell line. In unstimulated cells, GM-CSF mRNA was undetectable by Northern blot. Upon activation, it was detected from 3 h onward, with a progressive increase in the levels of the transcript up to 24 h of stimulation. Whereas cycloheximide treatment at the time of stimulation blocked mRNA induction, its addition at later times resulted in a marked increase in transcript levels. Run-on analysis showed that transcription of the GM-CSF gene was low to undetectable in unstimulated cells; stimulation led to transcriptional activation, which was weak at 6 h but had increased 16-fold at 24 h. In addition, the mRNA half-life decreased during activation, from 2.5 h at 6 h down to 45 min at 24 h. Cycloheximide treatment increased GM-CSF mRNA half-life (3- and 4-fold, respectively). Our results show: (a) both transcriptional and posttranscriptional signals regulate GM-CSF mRNA levels in activated Jurkat cells, (b) de novo protein synthesis is required for mRNA induction, whereas destabilizing labile proteins control the transcript stability, and (c) a shift from a posttranscriptional to a predominant transcriptional control of GM-CSF gene expression occurs during activation.

In vivo use of rIL-2 autologous BMT may be the means of reproducing a kind of "adoptive immunotherapy" from grafted cells after allogeneic BMT. This approach may enhance the spontaneous generation of cytotoxic T-cells and NK cells which are presumably involved in this immunotherapy. Potential risks of such an approach would be to increase the usual toxicity of rIL-2 and to jeopardize the hemopoietic reconstitution. To determine the feasibility of this approach we have treated 19 poor prognosis patients with a succession of autologous BMT followed 78 +/- 12 days later by a continuous infusion of rIL-2. Eighteen million international units (IU) per m2 per day of Proleukine (CETUS, Amsterdam, The Netherlands) were administrated over 6 or 12 days. No patient died of the procedure. Clinical toxicity related to rIL-2 was not increased. Hemopoietic toxicity, significant both for platelets and granulocytes, was transient. Immune stimulation was dramatic for lymphocytes and subpopulations (CD3+ and NK cells) and for cytolytic functions (NK and LAK activity). This trial establishes the feasibility of administration of high doses of rIL-2, 2 months after autologous BMT. In this setting a 6 day period of continuous infusion of 18 million per m2 per day of Proleukine appears to be a regularly tolerable dosage conducting to a major immune activation and invites further studies to determine the clinical impact of such an approach.

The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the growth of multiple myeloma (MM) was investigated in 21 patients with MM. In 17 patients with proliferating myeloma cells in vivo, recombinant GM-CSF significantly increased the endogenous-IL-6-mediated spontaneous myeloma cell proliferation occurring in 5-day cultures of tumor cells in vitro (P less than .01). Furthermore, GM-CSF was detected in 5-day culture supernatants of myeloma bone marrow cells. This endogenous GM-CSF was produced by the myeloma bone marrow microenvironment but not by myeloma cells and contributed to the spontaneous myeloma-cell proliferation observed in 5-day cultures. In fact, this proliferation was partially blocked (67%) by anti-GM-CSF monoclonal antibodies. The stimulatory effect of rGM-CSF was mediated through IL-6 because it was abrogated by anti-IL-6 monoclonal antibodies. rGM-CSF did not reproducibly increase the endogenous IL-6 production in short-term cultures of bone marrow cells of MM patients. Using an IL-6-dependent myeloma cell line (XG-1 cell line), rGM-CSF was shown to act directly on myeloma cells stimulating by twofold their IL-6 responsiveness. rGM-CSF did not induce any IL-6 production in XG-1 cells, nor was it able to sustain their growth alone. Although no detectable GM-CSF levels were found in the peripheral or bone marrow blood of MM patients, it is possible that GM-CSF, produced locally by the tumoral environment, enhances the IL-6 responsiveness of myeloma cells in vivo in a way similar to that reported here in vitro.

We report here 16 autologous bone marrow transplantations (ABMT) for poor prognosis B or pre-B malignancies (16 acute lymphoblastic leukemias (ALL), three Burkitt lymphomas, one multiple myeloma) in 11 adults and five children where in vitro purging was accomplished by means of floating immunobeads. This method was developed to avoid non-specific killing by complement or toxin or batch-to-batch variability and provides a 3 log reduction of tumor in a model of B lymphoid malignancies. Low density bone marrow mononuclear cells were incubated for 30 min at 4 degrees C with anti CD10 (ALB2 Immunotech) and/or anti CD19 (Bg4) monoclonal antibodies (MoAb) and then mixed with low density polypropylene beads precoated with a rat antimouse MoAb. After 1 h at 4 degrees C the beads with target cells were decanted; the depleted marrow was collected through a microfilter and cryoperserved. After immunodepletion the recovery of nucleated cells was 75% with a median of 0.75 x 10(8) cells/kg (range 0.3-3.6) and the recovery of hematopoietic progenitors was 83% with a median of 2.9 x 10(4) CFU-GM/kg. The conditioning regimen consisted of busulfan 16 mg/kg and melphalan 140 mg/m2 for three patients, fractionated total body irradiation (TBI) following melphalan 140 mg/m2 for nine patients, TBI and cyclophosphamide 120 mg/m2 for two patients and TBI associated with melphalan and cyclophosphamide for two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The c-fms proto-oncogene product, which is the receptor for the macrophage colony-stimulating factor CSF-1, is always found expressed in acute myeloid leukemia cells, irrespective of their stage of differentiation according to the FAB classification (Dubreuil P, Torrès H, Courcoul M, Birg F, Mannoni P. Blood 1988;72:1081-1085). We have extended this study and looked for c-fms expression in poorly differentiated myeloid leukemias, in a series of acute leukemias of either T or B origin and in biphenotypic leukemias. We now report that expression of c-fms is still related to the myeloid origin of the leukemic proliferation, but that it can also be found in some acute leukemias presenting clonal rearrangements of the T cell receptor gene. Thus expression of the c-fms/CSF-1 receptor may not be exclusively a marker for myeloid proliferations.

A group of polypeptide factors that regulate cell growth and differentiation has been tested for their biological activities on the growth and differentiation of leukemic cells isolated from patients with Acute Myeloid Leukemias (AML). The effects of Transforming Growth Factor beta 1 (TGF beta), Tumor Necrosis Factor alpha (TNF alpha), Interferon gamma (IFN gamma) and LIF-HILDA were compared on leukemic cells cultured in vitro for seven days. Spontaneously growing leukemic cells were selected in order to study either inhibition or enhancement of proliferation induced by these factors. Only TGF beta 1 was found to induce a clear inhibition of leukemic proliferation in all cases tested. Recombinant TNF alpha and IFN gamma were found to induce either inhibition or enhancement of the proliferation on separate specimens. Under the conditions of culture, it was not possible to document any effect of LIF-HILDA. Cell differentiation and cell maturation were documented studying the modulation of cell surface antigens. TGF beta did not modify antigen expression on the cells surviving after 3 days in culture. Both TNF alpha and IFN gamma were found to enhance the expression of adhesion molecules and to a lesser extent, the expression of some lineage associated antigens. No effect of LIF-HILDA on antigen modulation was documented in the cases tested. These data confirm that TGF beta is by itself a potent inhibitor of the myeloid leukemia cells proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Les cellules souches du sang peripherique (CSSP) sont des produits de cytapherese, obtenus chez des malades ayant recu une chimiotherapie aplasiante ou un facteur de croissance hematopoietique recombinant, tels le GM-CSF ou le G-CSF. La proportion de veritables cellules souches hematopoietiques dans ces populations cellulaires est beaucoup plus faible que celle de progeniteurs plus murs ou de cellules differenciees. Elles procurent cependant une reconstitution hematopoietique souvent plus rapide que celle obtenue apres transplantation de moelle osseuse et permettent une reduction de la morbidite associee a la chimiotherapie a tres forte dose appliquee aux malades atteints de cancers de mauvais pronostic. Les nouveaux procedes de selection des progeniteurs, les cultures liquides avec des cytokines («expansion in vitro»), vont contribue a elargir les applications de la transplantation de cellules souches hematopoietiques. De plus, ces cellules sont une cible interessante pour les tentatives de therapie genique

The rapid appearance of acute respiratory distress during the course of 25 hyperleukocytic leukemias was associated with the rapid increase of the leukocytosis. The regression of the tachypnea was spectacular when treating hyperleukocytosis by exchange transfusion and chemotherapy. Blood gas studies, although blurred to some extent by in vitro blast consumption of oxygen, showed a hypoxemia with a hypo-or normocapnia. The symptoms seem to be related to the leukostasis by the mechanical obstruction of the pulmonary capillaries. This leukostasis was shown to be responsible for a septal and alveolar oedema. The high frequency of this syndrome during the course of AGL and of acute phase of CGL seems to be linked to the low deformability of the myeloblasts. In CGL at its chronic phase, CLL or even in ALL, the absence of this syndrome could be explained by the greater deformability of the circulating cells. The hyperleukocytic AGL patients which do not have this syndrome are all characterized by a stable or slowly increasing leukocytosis. Thus, this syndrome seems to characterized by hyperleukocytic granulocytic leukemias with a rapid blood leukocyte doubling rate. Treatment in such cases is an emergency.