Antiapoptotic Effect of Granulocyte Colony-Stimulating Factor, Granulocyte-Macrophage Colony-Stimulating Factor, and Cyclic AMP on Human Neutrophils: Protein Synthesis-Dependent and Protein Synthesis-Independent Mechanisms and the Role of the Janus Kinase-STAT Pathway

2003 ◽  
Vol 77 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Chikahiko Sakamoto ◽  
Kenichi Suzuki ◽  
Fumihiko Hato ◽  
Mika Akahori ◽  
Taro Hasegawa ◽  
...  
Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4210-4210
Author(s):  
Yoshiki Uemura ◽  
Makoto Kobayashi ◽  
Hideshi Nakata ◽  
Tetsuya Kubota ◽  
Hirokuni Taguchi

Abstract Many cases of tumors that produce granulocyte-colony stimulating factor (G-CSF) or granulocyte macrophage-colony stimulating factor (GM-CSF) have been reported. However, the biological properties regulatory mechanisms of the overproduction of G-CSFor GM-CSF by tumor cells are not well known. We present the role of protein kinase C (PKC) pathways in the constitutive expression of G-CSF and GM-CSF by lung cancer cells. We previously established two lung cancer cell lines, OKa-C-1 and MI-4, that constitutively produce an abundant dose of G-CSF and GM-CSF. We showed that the PKC activator; phorbol 12-myristate 13-acetate (PMA) stimulated the production of GM-CSF in a dose-dependent manner and inversely reduced G-CSF in the cell lines. These effects of PMA were antagonized by PKC inhibitor; staurosporine. The induction of GM-CSF expression by PMA was mediated through the activations of nuclear factor (NF)-kB activation. The induction of G-CSF expression by staurosporine was mediated through p44/42 mitogen-activated protein kinase (MAPK) pathway signaling. PMA accelerated cell growth and inhibited cell death in the cell line. Whereas staurosporine acted inversely. GM-CSF induced by PMA might stimulate cell growth and suppress cell death. G-CSF expression by staurosporine appears to be related to the activation of p44/42 MAPK, and GM-CSF by PMA to NF-kB in OKa-C-1 and MI-4 cells. Figure Figure


Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 867-876 ◽  
Author(s):  
Sean E. Doyle ◽  
Judith C. Gasson

The high-affinity human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor (GMR) consists of an alpha (GMRα) and a common beta (βc) subunit. The intracellular domain of βc has been extensively characterized and has been shown to be critical for the activation of both the JAK/STAT and MAP kinase pathways. The function of the intracellular domain of GMRα, however, is not as well characterized. To determine the role of this domain in GMR signaling, an extensive structure-function analysis was performed. Truncation mutants α362, α371, and α375 were generated, as well as the site-directed mutants αVQVQ and αVVVV. Although α375β, αVQNQβ, and αVVVVβ stimulated proliferation in response to human GM-CSF, the truncation mutants α362β and α371β were incapable of transducing a proliferative signal. In addition, both α371 and αVVVV were expressed at markedly reduced levels, indicating the importance of residues 372 to 374 for proper protein expression. More importantly, we show that GMRα plays a direct role in the activation of the JAK/STAT pathway, and electrophoretic mobility shift assays (EMSA) indicate that both GMRα and βc play a role in determining the STAT5 DNA binding complex activated by the GMR. Thus, the intracellular domain of the human GMRα is important for activation of the JAK/STAT pathway and protein stabilization. © 1998 by The American Society of Hematology.


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