Urokinase inhibits HL-60 cell proliferation in vitro.
The binding of urokinase-type plasminogen activator (u-PA) to its receptor (u-PA-R) is required for morphological and functional maturation during monocyte differentiation of the promyelocytic leukaemia line HL-60. This paper reports that monocyte differentiation of HL-60 cells induced by 1,25 dihydroxyvitamin D2 (vitamin D2) results in a marked increase in expression of u-PA and u-PA-R. This increase in u-PA expression is of greater magnitude than is observed after culture with interferon-gamma (IFN gamma), another potent inducer of monocytic differentiation. Dimethyl sulphoxide (DMSO), an agent that induces granulocytic differentiation, also increased expression of u-PA. However, culture with the granulocyte-inducing all-trans retinoic acid (RA) did not induce an increase in surface expression of u-PA or u-PA-R. The vitamin D2-induced increase in cell-surface u-PA was not coincident with an increase in steady-state levels of u-PA mRNA, suggesting that intracellular stores of this protein, translational or post-translational mechanisms of regulation, or some other regulatory mechanism may be responsible for the increase in u-PA during differentiation. To ascertain an association between the increased expression of cell-surface u-PA and reduced proliferation that accompanies differentiation, the effect of u-PA on cellular proliferation of HL-60 cells was measured. Both pro-u-PA (whole molecule) and fragments of u-PA that retained receptor-binding capability caused a marked inhibition of HL-60 proliferation in the absence of vitamin D2.(ABSTRACT TRUNCATED AT 250 WORDS)
Howell
A L
AL
Department of Veterans Affairs Medical Center, White River Junction, VT 05009.
Hunt
J A
JA
James
T W
TW
Mazar
A
A
Henkin
J
J
Zacharski
L R
LR
D017660:Autoreceptors / Q000187:drug effects; D001665:Binding Sites; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003864:Depression, Chemical; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004872:Ergocalciferols / Q000494:pharmacology; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D010446:Peptide Fragments / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism / Q000494:pharmacology*
D017660:Autoreceptors; D004872:Ergocalciferols; D006133:Growth Substances; D009363:Neoplasm Proteins; C524898:PLAUR protein, human; D010446:Peptide Fragments; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins; D014212:Tretinoin; D007371:Interferon-gamma; D014568:Urokinase-Type Plasminogen Activator; C067551:saruplase; D004121:Dimethyl Sulfoxide