Integrin-linked kinase is involved in lactoferrin-induced anchorage-independent cell growth and survival in PC12 cells.
OBJECTIVE
Bovine lactoferrin (bLf) causes anchorage-independent cell growth in PC12 cells. The present study investigated the mechanisms involved in bLf-induced anchorage-independent cell growth and survival in PC12 cells.


METHODS
The number of adherent cells and suspended cells was estimated separately by using a methyl thiazol tetrazolium (MTT) assay, and the sum of both optical density (O.D.) (570 nm) values was used as a measure of the total number of cells.


RESULTS
Integrin-linked kinase (ILK) plays an important role in integrin and growth factor signaling pathways. Stable transfection of PC12 cells with a dominant negative kinase-deficient mutant of ILK (DN-ILK) inhibited bLf-induced anchorage-independent cell growth. The ILK activity in the parental cells was transiently activated after addition of bLf, whereas bLf-induced activation of ILK was blocked in DN-ILK-transfected cells. bLf also activated p38 mitogen-activated protein kinase (MAPK); however, the p38 MAPK activation was inhibited by stable DN-ILK transfection. Moreover, cell viability in the suspended cells by bLf strongly decreased after treatment with SB203580, an inhibitor of p38 MAPK.


CONCLUSIONS
These results suggest that ILK is involved in bLf-induced anchorage-independent cell growth and viability via activation of p38 MAPK.
Ishii
Toshiaki
T
Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan. ishii@obihiro.ac.jp
Uto
Tomoka
T
Mori
Kaori
K
Fujikawa
Ryu
R
D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D007781:Lactoferrin / Q000494:pharmacology*; D016716:PC12 Cells; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099200:Scaffold Protein ILK
D007781:Lactoferrin; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D000099200:Scaffold Protein ILK