Plasminogen activator gene expression is induced by the src oncogene product and tumor promoters.

摘要: Secretion of urokinase-type plasminogen activator (uPA) by chicken embryo fibroblasts (CEF) is increased approximately 50-fold following transformation Rous sarcoma virus (RSV). Using a cloned and fully sequenced uPA cDNA probe, we have established that this increase in production can be largely accounted for an cellular mRNA. CEF contained on average less than 1 molecule mRNA/cell, whereas RSV-CEF 25-60 molecules/cell. The mRNA levels was dependent the activity RSV-encoded transforming protein, protein-tyrosine kinase pp60v-src. Cells infected with RSV mutant encoding temperature-sensitive form src protein (ts-NY68) low when cultured at nonpermissive temperature high maintained permissive temperature. Temperature shift studies tsNY68-CEF demonstrated changes pp60v-src rapidly altered levels; content total RNA extracts decreased half-time kinetics 3-5 h. Serine/threonine-specific kinases also appear to modulate cultures. Exposure 24 h C activating agent phorbol myristate acetate (PMA) 20 260 molecules/cell, respectively. These data are consistent previously observed synergism between PMA increasing secretion. Nuclear run-on transcription analyses both way gene expression.