Enhanced ability of daniplestim and myelopoietin-1 to suppress apoptosis in human hematopoietic cells

Abstract

Modified and chimeric cytokines have been developed to aid in the recovery of hematopoietic precursor cells after myeloablative chemotherapy. The interleukin-3 (IL-3) receptor agonist, daniplestim, binds to the IL-3 receptor-␣ subunit with 60-fold greater affinity and induces cell proliferation and colony-forming unit formation 10-to 22-fold better than native IL-3. A chimeric cytokine, myelopoietin-1, composed of daniplestim and a G-CSF receptor agonist binds both the IL-3 and G-CSF receptors. While the in vivo effects of daniplestim and myelopoietin-1 are well described, the mechanisms by which they stimulate growth are not well understood. We have investigated the effects of daniplestim and myelopoietin-1 on the prevention of apoptosis in two human hematopoietic cell lines, OCI-AML.5 and AML 193. Daniplestim and myelopoietin-1 prevented apoptosis to a greater degree than native recombinant IL-3 or G-CSF as determined by annexin V/propidium iodide binding and TUNEL assays. Daniplestim and myelopoietin-1 promoted the maintenance of the mitochondrial membrane potential better than native IL-3 or G-CSF. These cytokines promoted a lower redox potential as higher levels of free radicals were detected after cytokine treatment than in cytokine-deprived cells implying increased respiration. These results indicate that daniplestim and myelopoietin-1 are able to prevent apoptosis in hematopoietic cells more effectively than native IL-3 and G-CSF. These effects of daniplestim and myelopoietin-1 may contribute to their effective ability to repopulate hematopoietic precursor cells after chemotherapy. Leukemia (2001Leukemia ( ) 15, 1203Leukemia ( -1216

Differential effects of kinase cascade inhibitors on neoplastic and cytokine-mediated cell proliferation

“…7,8,[18][19][20][21][22] Cell lines that grow in culture and remain cytokine-dependent represent models to understand the proliferation and malignant transformation of hematopoietic precursor cells. The murine IL-3/GM-CSF-dependent FDC-P1 cell line was isolated from the bone marrow of a normal DBA/2 mouse and resembles cells with a colony-forming unit granulocyte/macrophage morphology.…”

“…18 Spontaneous factorindependent cells are rarely recovered from this cell line, which makes it an attractive model system to analyze the effects that various oncogenes have on signal transduction and the transition to cytokine independence and leukemogenesis. 7,18,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Oncogene-transformed cytokine-independent cells have been obtained after infection/transfection of this cell line. 7 These cytokine-dependent and oncogene-transformed derivative cells represent appropriate tools to screen for novel therapeutic compounds as well as to evaluate their effectiveness in suppressing the growth and differentiation capacity of certain types of leukemias containing various oncogene mutations and chromosomal translocations.…”

Extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways cooperate in mediating cytokine-induced proliferation of a leukemic cell line

“…[9][10][11][12][13][14][15] FL has been shown to activate ERK MAP kinases in a murine hematopoietic cell line, BaF3. This cell line stably expresses human Flt3 and the ERK MAP kinase activation is necessary for FL-induced cell proliferation.…”

“…16 G-CSF has been shown to activate all three MAP kinases in hematopoietic cell lines. 7,15,17 Furthermore, ERK and p38 MAP kinase pathways were shown to be necessary for G-CSF-induced hematopoietic cell proliferation. 17 However, it is likely that hematopoiesis in vivo is mediated by a complex interplay of signaling pathways activated by multiple cytokines.…”

The enhanced in vitro hematopoietic activity of leridistim, a chimeric dual G-CSF and IL-3 receptor agonist

“…32 A prototype MPO (SC-68420) was created containing the IL-3 receptor agonist moiety present in daniplestim linked to rhG-CSF that was shown to enhance the proliferation and suppress apoptosis of responsive cell lines. [33][34][35][36] Treatment with this prototype MPO in a non-human primate model of radiation-induced myelosuppression resulted in a dramatic, dose-related improvement in the neutrophil and platelet nadir, a reduction in the duration of neutropenia and thrombocytopenia and a reduced time to recovery of neutrophil and platelet values. 37,38 Another IL-3 agonist, SC-65303, consisted of an N-and C-terminal truncated IL-3 receptor agonist containing a single E50D substitution (15-125, 50D), and showed two-to four-fold better potency than rhIL-3 in IL-3 receptor-positive cell lines.…”