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Cell density‐dependent secretion of plasminogen activator by 3T3 cells
Author(s) -
Chou IihNan,
O'Donnell Sara P.,
Black Paul H.,
Roblin Richard O.
Publication year - 1977
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040910104
Subject(s) - plasminogen activator , 3t3 cells , secretion , egta , extracellular , intracellular , cell culture , activator (genetics) , biology , microbiology and biotechnology , chemistry , biochemistry , transfection , endocrinology , calcium , organic chemistry , gene , genetics
Abstract The expression of extracellular fibrinolytic activity in untransformed 3T3 cell cultures depends on the growth state of the cells. Actively growing 3T3 cultures exhibit a relatively high level of fibrinolysis, which decreases progressively as the cells become confluent and density‐inhibited. The low level of fibrinolytic activity in confluent 3T3 cultures is due to a diminution in secretion of plasminogen activator since the intracellular level of plasminogen activator remains high. The amount of plasminogen activator observed in growing 3T3 cultures varies depending upon whether the cells are passaged with trypsin/EDTA solution, or with the Ca ++ selective chelating agent, ethylene‐bis (oxyethylenenitrilo) tetraacetic acid (EGTA). However, in cells passaged using either agent, the amount of plasminogen activator secreted is always greatest when the cells are actively growing and decreases thereafter. In contrast to confluent 3T3 cultures, dense cultures of SV40‐virus transformed 3T3 cells continued to secrete relatively large amounts of plasminogen activator. The ability to decrease secretion of plasminogen activator as cells become dense may be an important characteristic of cells which demonstrate density‐dependent inhibition of cell multiplication in vitro.