SCF and TLR4 ligand cooperate to augment the tumor-promoting potential of mast cells

Cancer Immunol Immunother. 2012 Mar;61(3):303-12. doi: 10.1007/s00262-011-1098-z. Epub 2011 Aug 30.


Mast cells may have either antitumor or tumor-promoting potential. Nevertheless, mast cells in tumor microenvironment have been found to promote tumor growth. So far the mechanisms underlying the modulation of mast cell function in tumor microenvironment remains to be fully elucidated. Here, we report that tumor-promoting potential of mast cells could be augmented by molecules released from damaged tumor cells through cooperative stimulation of stem cell factor (SCF) and ligand for Toll-like receptor 4 (TLR4). Co-simulation with SCF and TLR4 ligand inhibited mast cell degranulation, but efficiently induced the production and secretion of VEGF, PDGF, and IL-10. Although TLR4 ligand alone may induce IL-12 expression in mast cells, co-stimulation with SCF and TLR4 ligand induced the expression of IL-10, but not IL-12, in mast cells. The phosphorylation of GSK3β was crucial for the effect of SCF and TLR4 ligand. In addition to inducing phosphorylation of GSK3β at Ser9 through PI3K pathway, SCF and TLR4 ligand cooperated to induce phosphorylation of GSK3β at Tyr216 by simultaneous activation of ERK and p38MAPK pathways. Both phospho-Ser9 and phospho-Tyr216 of GSK3β were required for IL-10 expression induced by SCF/TLR4 ligand, whereas suppressive effect of SCF/TLR4 ligand on mast cell degranulation was related to phospho-Tyr216. Importantly, the effect of SCF and TLR4 ligand on mast cells could be abrogated by inhibiting phosphorylation of GSK3β at Tyr216. These findings disclose the mechanisms underlying the modulation of mast cell function in tumor microenvironment, and suggest that inhibiting GSK3β in mast cells will be beneficial to the treatment of cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Bone Marrow Cells / drug effects
  • Bone Marrow Cells / immunology
  • Bone Marrow Cells / physiology
  • Cell Degranulation / drug effects
  • Cell Degranulation / immunology
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / immunology
  • Cells, Cultured
  • Cromolyn Sodium / pharmacology
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Interleukin-10 / genetics
  • Interleukin-10 / metabolism
  • Interleukin-12 / genetics
  • Interleukin-12 / metabolism
  • Ligands
  • Lipopolysaccharides / pharmacology
  • Mast Cells / drug effects
  • Mast Cells / immunology*
  • Mast Cells / physiology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Neoplasms, Experimental / immunology*
  • Neoplasms, Experimental / metabolism
  • Neoplasms, Experimental / pathology
  • Phosphorylation / drug effects
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stem Cell Factor / immunology*
  • Stem Cell Factor / metabolism
  • Stem Cell Factor / pharmacology
  • Toll-Like Receptor 4 / immunology*
  • Toll-Like Receptor 4 / metabolism
  • Tumor Burden / drug effects
  • Tumor Burden / immunology
  • Tumor Microenvironment / drug effects
  • Tumor Microenvironment / immunology


  • Ligands
  • Lipopolysaccharides
  • Stem Cell Factor
  • Toll-Like Receptor 4
  • Interleukin-10
  • Interleukin-12
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Glycogen Synthase Kinase 3
  • Cromolyn Sodium