Characterization of a human transforming gene isolated from T24 bladder carcinoma cells.

A human transforming gene present in T24 bladder carcinoma cells has been molecularly cloned. The transforming sequences have been located within a 4.6 kilo base pair (kbp) DNA fragment that transforms NIH/3T3 cells with a specific activity of 5 X 10(4) focus-forming units/pmol. Homologous sequences present in normal human DNA have also been molecularly cloned. Comparison of the restriction endonuclease maps of the normal and transforming genes did not reveal any significant differences. These results suggest that subtle molecular changes are responsible for the acquisition of malignant properties by this gene in T24 cells. The T24 oncogene was found to be unrelated to transforming genes present in a variety of human tumors other than bladder carcinomas. In contrast, the T24 oncogene is highly related to the onc genes of the BALB and Harvey strains of murine sarcoma viruses ( MSVs ). Preliminary characterization of the transcriptional and translational products of the T24 oncogene suggests that this gene is transcribed into a 1.2-kbp poly(A)-containing RNA whose translation yields a 23,000-dalton protein antigenically related to the transforming gene products of BALB and Harvey MSVs .