OBJECTIVETo explore the expression, characteristics and roles of macrophage colony-stimulating factor receptor (M-CSF-R) in human leukemia cell lines.

METHODSPeripheral blood mononuclear cells (PBMCs) collected from 3 healthy persons, cord blood mononuclear cells (CBMCs) collected from 5 healthy persons and 4 human myelomonocytic leukemia cell lines including J6-1, J6-2, K562 and HL-60 were studied by using ABC immunoperoxidaes assay, indirect immunofluorescene staining, flow cytometry, and Western blot.

RESULTSM-CSF-R was noticed to be localized in the cytoplasm, nucleus and at the membrane in 4 human leukemia cell lines; expression of M-CSF-R was not detected in normal human PBMCs without PHA stimulation. Human PBMCs stimulated by PHA expressed a low level of M-CSF-R. Frequencies of membrane bound M-CSF-R (M-CSF-mR) expression in J6-1, J6-2, K562 and HL-60 were 78.9%, 72.6%, 54.9% and 58.0% respectively. Frequencies of cytoplasm and nucleus associated M-CSF-R (M-CSF-cnR) were 52.3%, 44.3%, 28.0% and 65.3% respectively. One form of M-CSF-R with a molecular weight of 120 000 was detected both in the cytoplasm and nucleus of HL-60 cells. The half-life of M-CSF-cnR in leukemia cells mentioned above was longer than that of corresponding M-CSF-R in stimulated CBMCs, and the half-life of M-CSF-mR in leukemia cells was extended except that of M-CSF-mR in K562 cells. Both anti-M-CSF-R monoclonal antibody and recombinant human M-CSF soluble receptor could cause the growth arrest of HL-60 cell in G(0)/G(1) phase, and could inhibit the formation of colony of HL-60 cell in soft agarose.

CONCLUSIONSExpression of M-CSF-R in leukemia cells is heterogeneous. The accumulation of cellular M-CSF-R results in the low degradation rate of cellular M-CSF-R in leukemia cells, which could be a potential mitotic signal. Signal mediated by M-CSF-R is important and necessary for the growth of HL-60 cell.

Cell Line ; HL-60 Cells ; Humans ; Leukemia ; Leukocytes, Mononuclear ; metabolism ; Macrophage Colony-Stimulating Factor ; metabolism ; Receptor, Macrophage Colony-Stimulating Factor ; Tumor Cells, Cultured

OBJECTIVETo investigate the levels of IL-18 in the bone marrow of both normal subjects and patients with hematological diseases and to determine the possible significance of IL-18 in pathogenesis of some hematological malignancies.

METHODSThe IL-18 mRNA levels in the bone marrow of 140 patients with hematological diseases and 15 normal donors were determined by the semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Immunohistochemical method was used to detect IL-18 protein in 12 patients with acute myeloid leukemia (AML). The possible regulation of IL-18 for proliferation of some leukemia cells was investigated using antisense techniques.

RESULTSIL-18 mRNA levels were obviously higher in the patients with leukemia or other malignant hematological diseases (OMHD) than in normal donors. However, no significant difference was found in the level of transcription between patients with iron deficiency anemia (IDA) and normal controls. Immunohistochemical method confirmed the presence of IL-18 protein in 10 out of 12 AML cases with positive transcription. By 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, IL-18 antisense oligodeoxynucleotides (ASON) clearly inhibited the growth of J6-1 and HL-60 cells (42% and 12% inhibited, respectively) in a dose-dependent manner.

CONCLUSIONSIL-18 was detected at elevated levels in the bone marrow of patients with some hematological malignancies, and might be involved in the proliferation of certain leukemic cells in vivo through an autocrine mechanism.

Adolescent ; Adult ; Bone Marrow ; metabolism ; Cell Division ; drug effects ; Dose-Response Relationship, Drug ; Female ; Humans ; Immunohistochemistry ; Interleukin-18 ; analysis ; antagonists & inhibitors ; genetics ; Leukemia ; drug therapy ; metabolism ; pathology ; Male ; Middle Aged ; Oligonucleotides, Antisense ; pharmacology ; RNA, Messenger ; analysis