TY - JOUR
T1 - Fibrinolytic activity in a human fibrosarcoma cell line and evidence for the induction of plasminogen activator secretion during tumor formation
AU - Jones, Peter A.
AU - Laug, Walter E.
AU - Benedict, William F.
N1 - Funding Information:
This work was supported by a contract from the National Institute. W. F. B. is the recipient of a Career Development from the National Cancer Institute.
PY - 1975/10
Y1 - 1975/10
N2 - Seven clones were isolated from the HT1080 human fibrosarcoma cell line using a fibrinagarose overlay technique. Three of these clones induced lysis of the fibrin overlay, whereas four did not. The extracellular and intracellular levels of protease were then measured using 125I-fibrin plates incubated with acid-treated human serum. The extracellular protease can be directly assayed in the medium from cells incubated with 10% fetal calf serum. Although there were large differences in the amounts of protease secreted by these two sets of clones, the intracellular levels of protease were similar. No significant differences were found between the abilities of the cells to grow in soft agar or as tumors in immunosuppressed hamsters. However, cells grown from tumors derived from all the low secretors of protease showed an increase in the amount of protease secreted. It appeared, therefore, that the secretion of protease might be selected for or induced during tumor growth. Further detailed studies with one of the low secreting clones (clone E) suggested an inductive rather than a selective mechanism for this increase in extracellular plasminogen activator.
AB - Seven clones were isolated from the HT1080 human fibrosarcoma cell line using a fibrinagarose overlay technique. Three of these clones induced lysis of the fibrin overlay, whereas four did not. The extracellular and intracellular levels of protease were then measured using 125I-fibrin plates incubated with acid-treated human serum. The extracellular protease can be directly assayed in the medium from cells incubated with 10% fetal calf serum. Although there were large differences in the amounts of protease secreted by these two sets of clones, the intracellular levels of protease were similar. No significant differences were found between the abilities of the cells to grow in soft agar or as tumors in immunosuppressed hamsters. However, cells grown from tumors derived from all the low secretors of protease showed an increase in the amount of protease secreted. It appeared, therefore, that the secretion of protease might be selected for or induced during tumor growth. Further detailed studies with one of the low secreting clones (clone E) suggested an inductive rather than a selective mechanism for this increase in extracellular plasminogen activator.
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U2 - 10.1016/0092-8674(75)90015-X
DO - 10.1016/0092-8674(75)90015-X
M3 - Article
C2 - 1182804
AN - SCOPUS:0016754212
SN - 0092-8674
VL - 6
SP - 245
EP - 252
JO - Cell
JF - Cell
IS - 2
ER -