Platelet-derived endothelial cell growth factor mediates Rho-associated coiled-coil domain kinase messenger RNA expression and promotes cell motility.
BACKGROUND
Platelet-derived endothelial cell growth factor (PD-ECGF), whose expression is increased in several cancers, is an endothelial cell mitogen and has chemotactic activity in vitro and angiogenic activity in vivo. Tumors with high PD-ECGF expression tend to have frequent lymph node metastasis and are associated with poor outcome.


METHODS
We screened genes transduced by PD-ECGF transfection to the colon cancer cell line DLD-1 by using a complementary DNA microarray. Cell motility was evaluated by in vitro migration assay. Actin fiber polymerization was visualized by immunofluorescent detection of phalloidin.


RESULTS
Rho-associated coiled-coil domain kinase (ROCK1) was found to be significantly overexpressed in PD-ECGF transfectants compared with mock cells. PD-ECGF transfectants showed higher cell motility than mock cells. The parental cell, DLD-1, with recombinant PD-ECGF showed higher cell motility than that without recombinant PD-ECGF, in which motility was blocked by the neutralizing antibody of PD-ECGF or Y-27632, a specific inhibitor of ROCK1. Moreover, the actin fiber polymerization, which is a marker of activation of ROCK1, was higher in PD-ECGF transfectants than in mock cells.


CONCLUSIONS
PD-ECGF expression may be associated with cancer cell migration via activation of ROCK1. This may explain one mechanism by which tumors with high expression of PD-ECGF show aggressive behavior.
Yoshinaga
Keiji
K
Department of Molecular and Surgical Oncology, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan.
Inoue
Hiroshi
H
Tanaka
Fumiaki
F
Mimori
Koshi
K
Utsunomiya
Tohru
T
Mori
Masaki
M
D000209:Acute-Phase Proteins / Q000494:pharmacology*; D002465:Cell Movement / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009362:Neoplasm Metastasis / Q000503:physiopathology*; D020411:Oligonucleotide Array Sequence Analysis; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D013939:Thymidine Phosphorylase / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D054460:rho-Associated Kinases
D000209:Acute-Phase Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C010781:acute-phase protein rho; D013939:Thymidine Phosphorylase; D017346:Protein Serine-Threonine Kinases; C515851:ROCK1 protein, human; D054460:rho-Associated Kinases