Expression of urokinase and its receptor in invasive and non-invasive prostate cancer cell lines.
We previously reported that extracellular matrix invasion by the prostate cancer cell lines, PC-3 and DU-145 was contingent on endogenous urokinase being bound to a specific cell surface receptor. The present study was undertaken to characterize the expression of both urokinase and its receptor in the non-invasive LNCaP and the invasive PC-3 and DU-145 prostate cells. Northern blotting indicated that the invasive PC-3 cells, which secreted 10 times more urokinase (680 ng/ml per 10(6) cells per 48 h) than DU-145 cells (63 ng/ml per 10(6) cells per 48 h), had the most abundant transcript for the plasminogen activator. This, at least, partly reflected a 3 fold amplification of the urokinase gene in the PC-3 cells. In contrast, urokinase-specific transcript could not be detected in the non-invasive LNCaP cells previously characterized as being negative for urokinase protein. Southern blotting indicated that this was not a consequence of deletion of the urokinase gene. Crosslinking of radiolabelled aminoterminal fragment of urokinase to the cell surface indicated the presence of a 51 kDa receptor in extracts of the invasive PC-3 and DU-145 cells but not in extracts of the non-invasive LNCaP cells. The amount of binding protein correlated well with binding capacities calculated by Scatchard analysis. In contrast, the steady state level of urokinase receptor transcript was a poor predictor of receptor display. PC-3 cells, which were equipped with 25,000 receptors per cell had 2.5 fold more steady state transcript than DU-145 cells which displayed 93,000 binding sites per cell.
Hollas
W
W
Department of Tumor Biology, M.D. Anderson Cancer Center, Houston, TX 77030.
Hoosein
N
N
Chung
L W
LW
Mazar
A
A
Henkin
J
J
Kariko
K
K
Barnathan
E S
ES
Boyd
D
D
D015152:Blotting, Northern; D015139:Blotting, Southern; D003432:Cross-Linking Reagents; D003947:Diagnostic Techniques, Radioisotope; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics; D055293:Receptors, Urokinase Plasminogen Activator; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics
D003432:Cross-Linking Reagents; C524898:PLAUR protein, human; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator