title: A formylated hexapeptide ligand mimics the ability of Wnt-5a to impair migration of human breast epithelial cells.
abstract: Loss of Wnt-5a protein expression is associated with shorter recurrence-free survival in breast carcinoma patients and increased motility in mammary cell lines. Based on sequence analysis of Wnt-5a, we identified 14 peptide fragments and investigated their ability to mimic the effects of Wnt-5a on mammary cell adhesion and migration. Two of these peptides significantly increased adhesion and impaired migration in the non-tumorigenic HB2 breast epithelial cell line and in the MDA-MB-468 breast cancer cell line, both of which show little endogenous expression of the Wnt-5a protein. We removed two amino acids at a time from the N terminus of the shorter of these two peptides to identify the shortest peptide that still inhibited migration. The influence on tumor cell adhesion was gradually lost and was no longer detectable when only six amino acids remained. However, formylation of the N-terminal methionine of this hexapeptide restored its effect on adhesion and reduced tumor cell motility via a Frizzled-5 receptor-dependent mechanism, even at a low pH such as encountered in breast tumor tissue. This formylated hexapeptide ligand induced a rapid cytosolic calcium signal, whereas it did not affect the cellular levels of unphosphorylated beta-catenin or active JNK. The novel formyl-Met-Asp-Gly-Cys-Glu-Leu peptide ligand is not only a valuable experimental tool but has also a potential role in antimetastatic treatment of the 50% of human breast cancer patients that have reduced endogenous Wnt-5a protein expression.
authors.affiliation: Department of Laboratory Medicine, Experimental Pathology, Lund University, Malmö University Hospital, SE20502 Malmö, Sweden.
authors.forename: Annette
authors.initials: A
authors.lastname: Säfholm
authors.forename: Karin
authors.initials: K
authors.lastname: Leandersson
authors.forename: Janna
authors.initials: J
authors.lastname: Dejmek
authors.forename: Christian Kamp
authors.initials: CK
authors.lastname: Nielsen
authors.forename: Bruno O
authors.initials: BO
authors.lastname: Villoutreix
authors.forename: Tommy
authors.initials: T
authors.lastname: Andersson
mesh_terms: D000595:Amino Acid Sequence; D001940:Breast / Q000166:cytology*; D001943:Breast Neoplasms / Q000473:pathology*; D020013:Calcium Signaling / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects*; D004847:Epithelial Cells / Q000166:cytology / Q000473:pathology; D005260:Female; D005561:Formates; D006801:Humans; D008024:Ligands; D018716:Molecular Mimicry; D010446:Peptide Fragments / Q000494:pharmacology*; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000502:physiology*; D051153:Wnt Proteins / Q000737:chemistry / Q000502:physiology*; D000071818:Wnt-5a Protein
chemical_list: D005561:Formates; D008024:Ligands; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C030544:formic acid