interleukin-8 and Leukemia--Myelomonocytic--Acute

Secretion of interleukin 8 (IL-8) and its regulation was investigated in myelomonocytic leukaemia cell lines. Quantification by ELISA revealed a constitutive production in the cell lines HL-60, ML-2, MONO-MAC-6 and MUTZ-3 ranging between 1500 and ca. 5000 pg/ml IL-8 per million cells. No measurable IL-8 was detected in the culture medium of MONO-MAC-1 and THP-1. Stimulation with lipopolysaccharide (LPS) or tetradecanoyl phorbol acetate (TPA) significantly increased the IL-8 level secreted by all cell lines; the best producers were TPA-treated MONO-MAC-6 and MUTZ-3 cultures, generating more than 50 000 pg/ml IL-8. Also the calcium ionophore A-23187, IL-13, macrophage colony-stimulating factor (M-CSF), thapsigargin, an inhibitor of the Ca(2+)-ATPase, and tumour necrosis factor-alpha (TNF-alpha) strongly enhanced the IL-8 production in MONO-MAC-6 cells. The glucocorticoid dexamethasone and the protein kinase inhibitor staurosporine distinctively inhibited the IL-8 production of MONO-MAC-6 cells. Thus, our results demonstrate a strong constitutive IL-8 secretion in human myelomonocytic leukaemia cell lines; the variety of different modulators affecting IL-8 production leads to the suggestion of a multiple regulation of IL-8 expression and secretion.

Topics: Humans; Interleukin-8; Leukemia, Myelomonocytic, Acute; Lipopolysaccharides; Monocytes; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

To compare the effect of ginsenoside Rg1 and its metabolite Rh1 on proinflammatory cytokines and their mRNA expression by THP-1 cells.. Human peripheral blood mononuclear cells (PBMC) were incubated with Rg1 and Rh1 at concentrations of 0.1, 1, 10, and 100 mg/L, and the cell proliferation was measured 24 h after incubation. Radioimmunoassay (RIA) was used to detect the production of proinflammatory cytokines, TNF alpha, IL-1 alpha, and IL-8. TNF alpha mRNA level was detected by reverse transcription polymerase chain reaction (RT-PCR) after administration of Rg1 and Rh1.. Rg1 and Rh1 (at concentration of 0.1, 1, 10, 100 mg/L) had no effect on PBMC proliferation. Rh1 1 mg/L could upregulate the productions of TNF (and IL-8 induced by lipopolysaccharides (LPS) 10 mg/L plus phorbol myristate acetate (PMA) 200 nmol/L, however, Rg1 showed an inhibitory effect on TNF alpha production induced by LPS 100 mg/L. Rg1 1 mg/L and Rh1 100 mg/L enhanced the production of IL-1 alpha level in THP-1 cells in the presence of LPS 10 mg/L. RT-PCR revealed that Rh1 stimulated TNF alpha mRNA expression in suitable stimulatory conditions.. Rg1 and Rh1 have different effects on the production of cytokines produced THP-1 cells stimulated by LPS and PMA.

Topics: Ginsenosides; Humans; Interleukin-1; Interleukin-8; Leukemia, Myelomonocytic, Acute; RNA, Messenger; Saponins; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Purified leukemic cells from 30 acute myeloid leukemia (AML) cases at diagnosis were investigated for the presence of interleukin 8 (IL-8) mRNA by Northern blot analysis. IL-8 specific transcripts were detected in uncultured blasts in 14/30 cases, 10/14 from patients with M4-M5 and 4/14 from cases with M0-M3 morphology. The transcript expression was associated with the detection of IL-8 molecule in blast cells by immunostaining performed on cytospin preparations. After 24-hour culture, a strong up-regulation or the appearance in cases negative before culture of IL-8 mRNA was observed in all cases tested, and culture supernatants contained high amounts of IL-8. Our data demonstrate that leukemic cells in AML are equipped with the functional apparatus for IL-8 production. Since IL-8 displays a wide range of biological activities, including the regulation of some membrane molecules relevant to adhesion and migration processes, its production by AML blasts might be of relevance for the pattern of leukemic growth.

Topics: Acute Disease; Cell Division; Gene Expression; Humans; Interleukin-8; Leukemia, Monocytic, Acute; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukemia, Myelomonocytic, Acute; Leukemia, Promyelocytic, Acute; RNA, Messenger; Tumor Cells, Cultured