Plasminogen activator activity in cultures from human tissues. An immunological and histochemical study

Fibrinolytic Activity of Cultured Cells Derived During Ethylnitrosourea-induced Carcinogenesis of Rat Brain

“…In general, the reports of other studies have also indicated the close relationship between growth in agar and fibrinolytic activity (Laug et al, 1975;Jones et al, 1976;Rifkin and Pollack, 1977). Howvever, there have been instances, apart from reports of the high fibrinolytic activity of normal kidney and lung cells (Laug et al, 1975;Bernik and Kwaan, 1969) where carcinogen-transformed cell lines able to grow in agar have not shown high fibrinolytic activity . The separation of fibrinolytic activity from growth in agar has been reported by Leavitt et al (1977) where a mutation causing the loss of hypoxanthine phosphoribosyltransferase activity resulted in the inability of transformed Syrian hamster cells to grow in agar, whilst they retained high fibrinolytic activity.…”

Inhibition of plasminogen activation by apo(a): role of carboxyl-terminal lysines and identification of inhibitory domains in apo(a)

“…Binding of plasminogen to the cell surface initiates pericellular plasminogen activation through interaction with its respective plasminogen activators: tPA and uPA. Both tPA and uPA have been shown to be expressed in a variety of cell types, including endothelial cells for tPA ( 51 ) and lung, kidney, and several tumor cell lines for uPA ( 52,53 ). It has been shown that tPA can directly bind to various cell types other than endothelial cells, such as platelets, monocytes, and monocytoid cells ( 30,39,54,55 ).…”

Modulation of cell-associated plasminogen activator activity by cocultivation of a stem cell and its tumorigenic descendant.

“…Increased levels of PA activity in cells have been correlated with the ability of cells to grow in agar (22,29), the ability of cells transformed by tumor viruses to form tumors in nude mice (28), and the ability of malignant melanoma cells to form tumors (7). Some normal cells have high levels of PA activity (1,4,5,38). For some clonal isolates of tumorigenic cell lines, no correlation between levels of PA activity and malignant transformation has been observed (9,19,35,41).…”