OVEREXPRESSION OF UROKINASE RECEPTOR INCREASES MATRIX INVASION WITHOUT ALTERING CELL-MIGRATION IN A HUMAN OSTEOSARCOMA CELL-LINE

Citation
K. Kariko et al., OVEREXPRESSION OF UROKINASE RECEPTOR INCREASES MATRIX INVASION WITHOUT ALTERING CELL-MIGRATION IN A HUMAN OSTEOSARCOMA CELL-LINE, Cancer research, 53(13), 1993, pp. 3109-3117
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Oncology
Journal title
ISSN journal
0008-5472
Volume
53
Issue
13
Year of publication
1993
Pages
3109 - 3117
Database
ISI
SICI code
0008-5472(1993)53:13<3109:OOURIM>2.0.ZU;2-K
Abstract
Proteolysis triggered by receptor-bound urokinase-type plasminogen act ivator (uPA) involves a cascade of species-specific molecular interact ions. To study the role of the uPA receptor (uPAR) in such interaction s, a human osteosarcoma cell line (HOS), which normally expresses low levels of uPAR, was transfected with human uPAR complementary DNA. One of several stably transformed clonal cells lines, designated 2A2, was characterized and compared to the parental HOS, revealing the followi ng: (a) stable incorporation of uPAR complementary DNA into the genome demonstrated by Southern blot analysis; (b) a 10-fold increase in ste ady state mRNA levels of uPAR assessed by Northern blot analysis; (c) a 2-fold increase in the surface expression of glycosylphosphatidvlino sitol anchored uPAR protein determined by enzyme-linked immunosorbent assay and by the specific binding of radiolabeled single chain uPA; (d ) a 2-fold increase in internalization and degradation of radiolabeled uPA/PAI-1 complexes; and (e) a 2-fold increase in receptor-bound uPA- mediated plasmin generation measured by the cleavage of a chromogenic substrate and degradation of I-125-I-labeled laminin. The involvement of uPAR in cellular processes was determined by comparing 2A2 and HOS cells in in vitro migration and invasion assays. The migration of 2A2 cells were slower on fibronectin-coated surfaces in a linear under-aga rose assay, but both cell lines migrated at the same rate on uncoated polycarbonate filters in Boyden chamber assays. In the invasion experi ments, 4 times more 2A2 than HOS cells penetrated through the barrier of reconstituted basement membrane Matrigel. These data suggest that u PAR does not potentiate random cell migration but facilitates matrix d egradation and subsequent cell invasion.