Malignant transformation of early passage rodent cells by a single mutated human oncogene.

When linked to transcriptional enhancers, the mutant Ha-ras-1 gene from the T24 bladder carcinoma cell line induces the complete malignant transformation of early passage cells, while the normal Ha-ras-1 proto-oncogene only induces immortalization. Therefore, mutated Ha-ras-1 does not require a cooperating gene to trigger malignant conversion and ras genes may be involved in the process of tumorigenesis at an earlier stage than previously suspected.