Production of plasminogen activator by a primary HSV-2-induced hamster fibrosarcoma and itsin vivo derived sublines

The plasminogen activator (PA) content of a primary HSV-2-induced hamster fibrosarcoma and sublines derived from its in vivo metastases was investigated using the indirect 125I-labeled fibrin plate method. Fresh tissue culture lines established from primary HSV-2-333-2-26 tumors were shown to produce levels of PA similar to sublines derived from lung or kidney foci that developed after resection of primary tumors. In comparison, normal hamster embryo fibroblast (NHEF) and baby hamster kidney cells produced little or no PA, although baby hamster lung fibroblasts produced intermediate levels of PA. In addition, no correlation was found between PA levels of the sublines and their ability to metastasize from subcutaneous tumors, although tumor cell lines were shown to produce significantly more PA than normal cells.