Transforming growth factor-beta1 produced by ovarian cancer cell line HRA stimulates attachment and invasion through an up-regulation of plasminogen activator inhibitor type-1 in human peritoneal mesothelial cells.
The processes of ovarian cancer dissemination are characterized by altered local proteolysis, cellular proliferation, cell attachment, and invasion, suggesting that the urokinase-type plasminogen activator (uPA) and its specific inhibitor (plasminogen activator inhibitor type-1 (PAI-1)) could be involved in the pathogenesis of peritoneal dissemination. We showed previously that expression of uPA and PAI-1 in the human ovarian cancer cell line HRA can be down-regulated by exogenous bikunin (bik), a Kunitz-type protease inhibitor, via suppression of transforming growth factor-beta1 (TGF-beta1) up-regulation and that overexpression of the bik gene can specifically suppress the in vivo growth and peritoneal dissemination of HRA cells in an animal model. We hypothesize that the plasminogen activator system in mesothelial cells can be modulated by HRA cells. To test this hypothesis, we used complementary techniques in mesothelial cells to determine whether uPA and PAI-1 expression are altered by exposure to culture media conditioned by HRA cells. Here we show the following: 1) that expression of PAI-1, but not uPA, was markedly induced by culture media conditioned by wild-type HRA cells but not by bik transfected clones; 2) that by antibody neutralization the effect appeared to be mediated by HRA cell-derived TGF-beta1; 3) that exogenous TGF-beta1 specifically enhanced PAI-1 up-regulation at the mRNA and protein level in mesothelial cells in a time- and concentration-dependent manner, mainly through MAPK-dependent activation mechanism; and 4) that mesothelial cell-derived PAI-1 may promote tumor invasion possibly by enhancing cell-cell interaction. This represents a novel pathway by which tumor cells can regulate the plasminogen activator system-dependent cellular responses in mesothelial cells that may contribute to formation of peritoneal dissemination of ovarian cancer.
Hirashima
Yasuyuki
Y
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Handayama 1-20-1, Hamamatsu, Shizuoka 431-3192, Japan.
Kobayashi
Hiroshi
H
Suzuki
Mika
M
Tanaka
Yoshiko
Y
Kanayama
Naohiro
N
Terao
Toshihiko
T
D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004848:Epithelium / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System; D008562:Membrane Glycoproteins / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D010051:Ovarian Neoplasms / Q000378:metabolism*; D010534:Peritoneal Neoplasms / Q000473:pathology / Q000556:secondary; D010537:Peritoneum / Q000166:cytology / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D014360:Trypsin Inhibitor, Kunitz Soybean; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism
D017077:Culture Media, Conditioned; D008562:Membrane Glycoproteins; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D011994:Recombinant Proteins; C109148:SPINT2 protein, human; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014360:Trypsin Inhibitor, Kunitz Soybean; D014568:Urokinase-Type Plasminogen Activator