Urokinase‐type plasminogen activator biosynthesis is induced by the EJ‐Ha‐ras oncogene in CL26 mouse colon carcinoma cells

CL26 murine colon carcinoma cells express urokinase‐type plasminogen activator (u‐PA) mRNA and activity after transfection with the activated c‐Ha‐ras‐1 (EJ‐ras) oncogene cloned from the EJ bladder carcinoma. PA activity and mRNA in control cells transfected with the non‐mutated c‐Ha‐ras‐1 (CO‐ras) gene remained negative. Ras mRNA was detected in EJ‐ras‐ and CO‐ras‐transfected cells, but not in untransfected or pSV₂‐neo‐transfected cells. These results indicate that u‐PA biosynthesis can be modulated by EJ‐Ha‐ras‐dependent pathways of signal transduction.