Role of adenovirus types 5 and 12 early region 1 b tumor antigens in oncogenic transformation

Deletion mutants of region E1 a of AD12 E1 plasmids: Effect on oncogenic transformation

“…This is further confirmed by our finding that the degree of oncogenicity in nude mice of cells transformed by Ad5 or Ad12 is determined by the identity of the Elb 60-kDa protein (Bernards et al, 1983).…”

“…Cells transformed by such mutant plasmids carrying deletions in the genes coding for these proteins are not tumorigenic in nude mice, which demonstrates that the Elb gene products have an important role in determining the oncogenicity of transformed cells (Jochemsen et aL, 1982;Bernards et aL, 1983). This is further confirmed by our finding that the degree of oncogenicity in nude mice of cells transformed by Ad5 or Ad12 is determined by the identity of the Elb 60-kDa protein (Bernards et al, 1983).…”

“…First, the Ela-encoded 13 S mRNA, or its translation product, is required for initi- ation of transcription of the Elb region (Bos and ten Wolde-Kraamwinkel, 1983). Since Elb expression is essential for complete transformation (Jochemsen et aL, 1982;Bernards et aL, 1983), it follows that the Ela activity which induces this expression is essential also. Several lines of evidence (Berk et aL, 1979;Jones and Shenk, 1979) indicate that expression of other early adenovirus genes is also controlled by region Ela.…”

“…The oncogenicity of the transformed cells depends on which serotype is used as the transforming agent. Primary rat cells transformed by adenovirus 12 (Ad12) are oncogenic after injection into syngeneic rats and into athymic nude mice, whereas cells transformed by Ad5 are nononcogenic in syngeneic rats, although they are weakly oncogenic in nude mice (Bernards et al, 1983).…”

Adenovirus E1A: remodelling the host cell, a life or death experience

“…The E1 regions of Ad2/5 and Ad12 were subjected to extensive genetic analysis (Jones andShenk, 1978, 1979;van der Eb et al, 1979;Bos et al, 1983;Gallimore et al, 1985;Breiding et al, 1988;Byrd et al, 1988b). These Ad E1 mutant viruses along with viral DNA transfection experiments revealed that the E1A region alone could only induce partial transformation or unstable transformation and that for full transformation and oncogenicity, E1A had to be complemented by functions provided by the E1B region (Houweling et al, 1980;Bernards et al, 1983a;Ruley, 1983;van den Elsen et al, 1983a,b;Gallimore et al, 1985;Barker and Berk, 1987;Byrd et al, 1988a,b).…”