A new type of antimetastatic peptide derived from fibronectin.
OBJECTIVE
We found previously that fibronectin (FN) has a cryptic functional site (YTIYVIAL sequence within the 14th type III repeat) opposing cell adhesion to extracellular matrix. A 22-mer FN peptide containing this site, termed FNIII14, inhibits beta1 integrin-mediated adhesion without binding to integrins. The present study shows that FNIII14 has the potential to prevent lymphoma cell metastasis.


METHODS
Antimetastatic effect of FNIII14 has been evaluated through in vitro or in vivo experiments.


RESULTS
FNIII14 inhibited the integrin alpha4beta1-mediated B lymphoma Ramos cell adhesion to VCAM-1 on venule endothelial cells, as well as to FN. Murine T lymphoma L5178Y-ML25 cells, which are known to metastasize to liver and spleen, preferentially adhered to vitronectin (VN) and migrated toward VN concentration gradients. FNIII14 abrogated both the integrin alphavbeta3-mediated adhesion and migration of L5178Y-ML25 cells. Inhibition of the alphavbeta3mediated L5178Y-ML25 cell adhesion by FNIII14 was reversed by phenylarsine oxide, a protein tyrosine phosphatase inhibitor. In addition, FNIII14 abrogated the VN-stimulated tyrosine phosphorylation of intracellular signaling proteins, including focal adhesion kinase (p125(FAK)) and paxillin, suggesting that such a diversity of FNIII14 effects might be because of the negative regulation of p125(FAK) and paxillin tyrosine phosphorylation, which has been involved in adhesion signals transduced by different integrins. The in vivo experiment using a murine metastasis model showed that FNIII14 would inhibit liver and spleen metastases of L5178Y-ML25 cells at a dose much lower than that of RGDS.


CONCLUSIONS
FNIII14 might be applicable as a new type of antimetastatic agent distinct from integrin-binding peptides.
Departments of Patho-Physiology and Analytical Chemistry, Faculty of Pharmaceutical Sciences, Science University of Tokyo, Tokyo 162-0826, Japan.
Rina
R
Kato
Tetsuya
T
Ishikawa
Sadahiro
S
Kamiya
Fumiko
F
Oguma
Masaaki
M
Ueki
Sumio
S
Goto
Hiroshi
H
Nakamura
Takashi
T
Katayama
Fumio
F
Fukai
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D003598:Cytoskeletal Proteins; D004730:Endothelium, Vascular / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D066298:In Vitro Techniques; D039041:Integrin alpha4beta1 / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000517:prevention & control* / Q000556:secondary; D016393:Lymphoma, B-Cell / Q000378:metabolism; D051379:Mice; D051419:Paxillin; D010446:Peptide Fragments / Q000494:pharmacology*; D010750:Phosphoproteins; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D011505:Protein-Tyrosine Kinases; D017469:Receptors, Fibronectin / Q000378:metabolism; D013160:Splenic Neoplasms / Q000517:prevention & control* / Q000556:secondary; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
D003598:Cytoskeletal Proteins; D005353:Fibronectins; D039041:Integrin alpha4beta1; C496061:PXN protein, human; D051419:Paxillin; D010446:Peptide Fragments; D010750:Phosphoproteins; C496062:Pxn protein, mouse; D017469:Receptors, Fibronectin; D019010:Vascular Cell Adhesion Molecule-1; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; C496051:Ptk2 protein, mouse