scholarly journals Mechanisms of Stem Cell Factor and Erythropoietin Proliferative Co-signaling in FDC2-ER Cells

Blood ◽  
1997 ◽  
Vol 90 (9) ◽  
pp. 3533-3545 ◽  
Author(s):  
Bhavana Joneja ◽  
Hong-Chi Chen ◽  
Dhaya Seshasayee ◽  
Amy L. Wrentmore ◽  
Don M. Wojchowski
Keyword(s):  
Stem Cell ◽  
Cell Lines ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Egf Receptor ◽  
Synergistic Effects ◽  
Ectopic Expression ◽  
Hematopoietic Progenitor Cell ◽  
Detectable Effect ◽  
Epo Receptor

Abstract Studies of hematopoietic progenitor cell development in vivo, ex vivo, and in factor-dependent cell lines have shown that c-kit promotes proliferation through synergistic effects with at least certain type 1 cytokine receptors, including the erythropoietin (Epo) receptor. Presently, c-kit is shown to efficiently support both mitogenesis and survival in the FDCP1 cell subline, FDC2. In this system, mitogenic synergy with c-kit was observed for ectopically expressed wild-type Epo receptors (wt-ER), an epidermal growth factor (EGF) receptor/Epo receptor chimera, and a highly truncated Epo receptor construct ER-Bx1. Thus, the Epo receptor cytoplasmic box 1 subdomain appears, at least in part, to mediate mitogenic synergy with c-kit. In studies of potential effectors of this response, Jak2 tyrosine phosphorylation was shown to be induced by Epo, but not by stem cell factor (SCF). In addition and in contrast to signaling in Mo7e and BM6 cell lines, in FDC2-ER cells SCF and Epo each were shown to rapidly activate Pim 1 gene expression. Recently, roles also have been suggested for the nuclear trans-factor GATA-1 in regulating progenitor cell proliferation. In FDC2-ER cells, the ectopic expression of GATA-1 had no detectable effect on Epo inhibition of apoptosis. However, GATA-1 expression did result in a selective and marked inhibition in mitogenic responsiveness to SCF and to a decrease in c-kit transcript expression. These studies of SCF and Epo signaling in FDC2–wt-ER cells serve to functionally map the ERB1 region as a c-kit–interactive domain, suggest that Pim1 might contribute to SCF and Epo mitogenic synergy and support the notion that SCF and Epo may act in opposing ways during red cell differentiation.

Optimal Proliferation of a Hematopoietic Progenitor Cell Line Requires Either Costimulation With Stem Cell Factor or Increase of Receptor Expression That Can Be Replaced by Overexpression of Bcl-2

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2569-2577 ◽  
Author(s):  
Huei-Mei Huang ◽  
Jian-Chiuan Li ◽  
Yueh-Chun Hsieh ◽  
Hsin-Fang Yang-Yen ◽  
Jeffrey Jong-Young Yen
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Line ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Stem Cell Differentiation ◽  
Hematopoietic Progenitor Cell ◽  
Hematopoietic Progenitor ◽  
Progenitor Cell Line

Abstract In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor  subunit (IL5R) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5–dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5R is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.

Optimal Proliferation of a Hematopoietic Progenitor Cell Line Requires Either Costimulation With Stem Cell Factor or Increase of Receptor Expression That Can Be Replaced by Overexpression of Bcl-2

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2569-2577 ◽  
Author(s):  
Huei-Mei Huang ◽  
Jian-Chiuan Li ◽  
Yueh-Chun Hsieh ◽  
Hsin-Fang Yang-Yen ◽  
Jeffrey Jong-Young Yen
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Line ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Stem Cell Differentiation ◽  
Hematopoietic Progenitor Cell ◽  
Hematopoietic Progenitor ◽  
Progenitor Cell Line

In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor  subunit (IL5R) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5–dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5R is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.

Downregulation of c-kit (Stem Cell Factor Receptor) in Transformed Hematopoietic Precursor Cells by Stroma Cells

Blood ◽  
1999 ◽  
Vol 93 (2) ◽  
pp. 554-563 ◽  
Author(s):  
Christoph Heberlein ◽  
Jutta Friel ◽  
Christine Laker ◽  
Dorothee von Laer ◽  
Ulla Bergholz ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Line ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Receptor Expression ◽  
General Mechanism ◽  
Ligand Interaction ◽  
Kit Ligand ◽  
Kit Receptor ◽  
Progenitor Cell Line

Abstract We show a dramatic downregulation of the stem cell factor (SCF) receptor in different hematopoietic cell lines by murine stroma. Growth of the human erythroid/macrophage progenitor cell line TF-1 is dependent on granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3). However, TF-1 cells clone and proliferate equally well on stroma. Independent stroma-dependent TF-1 clones (TF-1S) were generated on MS-5 stroma. Growth of TF-1S and TF-1 cells on stroma still requires interaction between c-kit (SCF receptor) and its ligand SCF, because antibodies against c-kit inhibit growth to less than 2%. Surprisingly, c-kit receptor expression (RNA and protein) was downregulated by 2 to 3 orders of magnitude in TF-1S and TF-1 cells grown on stroma. This stroma-dependent regulation of the kit receptor in TF-1 was also observed on exposure to kit ligand-negative stroma, thus indicating the need for heterologous receptor ligand interaction. Removal of stroma induced upregulation by 2 to 4 orders of magnitude. Downregulation and upregulation of c-kit expression could also be shown for the megakaryocytic progenitor cell line M-07e and was comparable to that of TF-1, indicating that stroma-dependent regulation of c-kit is a general mechanism. Downregulation may be an economic way to compensate for the increased sensitivity of the c-kit/ligand interaction on stroma. The stroma-dependent c-kit regulation most likely occurs at the transcriptional level, because mechanisms, such as splicing, attenuation, differential promoter usage, or mRNA stability, could be excluded.

Randomized comparison of progenitor-cell mobilization using chemotherapy, stem-cell factor, and filgrastim or chemotherapy plus filgrastim alone in patients with ovarian cancer.

1998 ◽  
Vol 16 (8) ◽  
pp. 2601-2612 ◽  
Author(s):  
A Weaver ◽  
J Chang ◽  
E Wrigley ◽  
E de Wynter ◽  
P J Woll ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Stem Cell ◽  
Peripheral Blood ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Randomized Study ◽  
Cd34 Cells ◽  
Cell Mobilization ◽  
High Yields ◽  
Higher Doses

PURPOSE This was the first randomized study to investigate the efficacy of peripheral-blood progenitor cell (PBPC) mobilization using stem-cell factor (SCF) in combination with filgrastim (G-CSF) following chemotherapy compared with filgrastim alone following chemotherapy. PATIENTS AND METHODS Forty-eight patients with ovarian cancer were treated with cyclophosphamide and randomized to receive filgrastim 5 microg/kg alone or filgrastim 5 microg/kg plus SCF. The dose of SCF was cohort-dependent (5, 10, 15, and 20 microg/kg), with 12 patients in each cohort, nine of whom received SCF plus filgrastim and the remaining three patients who received filgrastim alone. On recovery from the WBC nadir, patients underwent a single apheresis. RESULTS SCF in combination with filgrastim following chemotherapy enhanced the mobilization of progenitor cells compared with that produced by filgrastim alone following chemotherapy. This enhancement was dose-dependent for colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythrocyte (BFU-E), and CD34+ cells in both the peripheral blood and apheresis product. In the apheresis product, threefold to fivefold increases in median CD34+ and progenitor cell yields were obtained in patients treated with SCF 20 microg/kg plus filgrastim compared with yields obtained in patients treated with filgrastim alone. Peripheral blood values of CFU-GM, BFU-E, and CD34+ cells per milliliter remained above defined threshold levels longer with higher doses of SCF. The higher doses of SCF offer a greater window of opportunity in which to perform the apheresis to achieve high yields. CONCLUSION SCF (15 or 20 microg/kg) in combination with filgrastim following chemotherapy is an effective way of increasing progenitor cell yields compared with filgrastim alone following chemotherapy.

scholarly journals Expression of stem cell factor and c-kit in human neuroblastoma. The Children's Cancer Group

Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3465-3472 ◽  
Author(s):  
PS Cohen ◽  
JP Chan ◽  
M Lipkunskaya ◽  
JL Biedler ◽  
RC Seeger
Keyword(s):  
Stem Cell ◽  
Neural Crest ◽  
Cell Lines ◽  
Stem Cell Factor ◽  
Growth Regulation ◽  
Neuroblastoma Cell ◽  
Receptor Expression ◽  
Human Neuroblastoma ◽  
Neuroblastoma Cell Lines ◽  
Simultaneous Expression

Abstract During development, mice with mutations of stem cell factor (SCF) or its receptor c-kit exhibit defects in melanogenesis, as well as hematopoiesis and gonadogenesis. Because melanocytes derive from neural crest cells, the role of SCF and c-kit was investigated in the neural crest-derived childhood tumor neuroblastoma. Using reverse transcription-polymerase chain reaction analysis, simultaneous expression of steady-state mRNA for the SCF ligand and its receptor c- kit was found in 14 of 14 (100%) human neuroblastoma cell lines and clones and in 8 of 18 (45%) human neuroblastoma tumor samples. Functional blockade of c-kit receptors in the cell lines SK-N-BE(2) and SH-SY5Y using the mouse monoclonal anti-c-kit antibody SR-1 resulted in a significant decrease in cellular growth rate when measured by either 3H-thymidine incorporation or clonogenicity. In addition, higher levels of c-kit mRNA expression were associated with parental neuroblastoma cell lines and subclones with a neuronal (N) differentiation phenotype, whereas lower levels of c-kit mRNA were associated with neuroblastoma cell line subclones having a schwannian/glial/melanocytic pattern of differentiation. However, the differentiation phenotype of neuroblastoma cell lines was not directly altered when c-kit expression was blocked using the SR-1 antibody. In summary, these data indicate that c-kit receptor expression may play a significant role in the growth regulation of the two neuroblastoma cell lines examined and suggest that c-kit may also play a similar role in neuroblastoma growth regulation in vivo. Simultaneous expression of SCF and c-kit mRNA in both neuroblastoma cell lines and tumors implies that c-kit may act as part of an autocrine growth loop in conjunction with endogenous production of SCF in this disease.

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