High-molecular-weight serum protein complexes differentially promote cell migration and the focal adhesion localization of the urokinase receptor in human glioma cells
Kk. Hedberg et al., High-molecular-weight serum protein complexes differentially promote cell migration and the focal adhesion localization of the urokinase receptor in human glioma cells, EXP CELL RE, 257(1), 2000, pp. 67-81
The distribution of the urokinase-type plasminogen activator receptor (uPAR
) on human glioma cells was examined as a function of culture conditions, u
sing immunofluorescence and immunophotoelectron microscopy, Both uPAR coloc
alization with focal adhesion proteins and glioma cell motility were maxima
l in medium containing whole serum or a serum fraction retained by a 500,00
0 mol wt cutoff centrifugal concentration filter. High motility also took p
lace in medium containing a serum fraction passed by the 500,000 cutoff fil
ter but retained by a 100,000 cutoff filter and in minimal medium containin
g added vitronectin; however, under these conditions only a small percentag
e of the otherwise abundant focal adhesions contained colocalized uPAR, Gli
oma cells in minimal medium with added laminin migrated with a highly elong
ated morphology but without either classical focal adhesions or well-define
d uPAR labeling. In contrast, glioma cells in minimal medium with no additi
ons did not migrate, nor did they adhere well or display defined labeling p
atterns for focal adhesion proteins or uPAR, The results indicate that high
-molecular-weight serum protein complexes promote both uPAR focal adhesion
colocalization and cell migration in glioma cells. However, conditions can
be selected in which migration takes place with minimal uPAR-focal adhesion
localization, as well as in the absence of apparent-focal adhesions. (C) 2
000 Academic Press.