Adenovirus E1a as a tumor-suppressor gene.

The E1a gene of group C adenoviruses is one of the most studied transforming genes of DNA tumor viruses. These transforming genes have been conventionally considered as dominant oncogenes since they transform cells in vitro and many of the resulting transformed cell lines induce tumors in experimental animals. It now appears that, in addition to its well-known transforming activities, E1a possesses activities which suppress transformation, tumorigenesis and malignant progression (metastasis) of tumor cells. Thus, E1a appears to meet the definition of both a dominant oncogene and a tumor-suppressor gene.