title: Transactivation of the epidermal growth factor receptor by formylpeptide receptor exacerbates the malignant behavior of human glioblastoma cells.
abstract: The G protein-coupled formylpeptide receptor (FPR), which mediates leukocyte migration in response to bacterial and host-derived chemotactic peptides, promotes the chemotaxis, survival, and tumorigenesis of highly malignant human glioblastoma cells. Because glioblastoma cells may also express other receptors for growth signals, such as the epidermal growth factor (EGF) receptor (EGFR), we investigated the role of EGFR in the signaling cascade of FPR and how two receptors cross-talk to exacerbate tumor growth. We found that N-formyl-methionyl-leucyl-phenylalanine, an FPR agonist peptide, rapidly induced EGFR phosphorylation at tyrosine residue (Tyr) 992, but not residues 846, 1068, or 1173, in glioblastoma cells, whereas all these residues were phosphorylated after only EGF treatment. The FPR agonist-induced EGFR phosphorylation in tumor cells was dependent on the presence of FPR as well as Galphai proteins, and was controlled by Src tyrosine kinase. The transactivation of EGFR contributes to the biological function of FPR in glioblastoma cells because inhibition of EGFR phosphorylation significantly reduced FPR agonist-induced tumor cell chemotaxis and proliferation. Furthermore, depletion of both FPR and EGFR by short interference RNA abolished the tumorigenesis of the glioblastoma cells. Our study indicates that the glioblastoma-promoting activity of FPR is mediated in part by transactivation of EGFR and the cross-talk between two receptors exacerbates the malignant phenotype of tumor cells. Thus, targeting both receptors may yield antiglioblastoma agents superior to those targeting one of them.
authors.affiliation: Laboratory of Molecular Immunoregulation, Cancer and Inflammation Program, Science Applications International Corporation-Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702-1201, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Jinyue
authors.initials: J
authors.lastname: Hu
authors.forename: Xiuwu
authors.initials: X
authors.lastname: Bian
authors.forename: Keqiang
authors.initials: K
authors.lastname: Chen
authors.forename: Wanghua
authors.initials: W
authors.lastname: Gong
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Dunlop
authors.forename: O M Zack
authors.initials: OM
authors.lastname: Howard
authors.forename: Ji Ming
authors.initials: JM
authors.lastname: Wang
mesh_terms: D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005909:Glioblastoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D015151:Immunoblotting; D020239:Receptor Cross-Talk; D044042:Receptors, Formyl Peptide / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D015533:Transcriptional Activation
chemical_list: D044042:Receptors, Formyl Peptide; D066246:ErbB Receptors