ENHANCED PROLIFERATION, GROWTH-FACTOR INDUCTION AND IMMORTALIZATION BY ADENOVIRUS E1A 12S IN THE ABSENCE OF E1B

Authors
Citation
Mp. Quinlan, ENHANCED PROLIFERATION, GROWTH-FACTOR INDUCTION AND IMMORTALIZATION BY ADENOVIRUS E1A 12S IN THE ABSENCE OF E1B, Oncogene, 9(9), 1994, pp. 2639-2647
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Genetics & Heredity",Oncology
Journal title
ISSN journal
0950-9232
Volume
9
Issue
9
Year of publication
1994
Pages
2639 - 2647
Database
ISI
SICI code
0950-9232(1994)9:9<2639:EPGIAI>2.0.ZU;2-3
Abstract
Immortalization and transformation of primary epithelial cells require s expression of the adenovirus E1A and E1B genes, respectively. The E1 A gene is involved in growth stimulatory processes. Little is known ab out the mechanism utilized by E1B, however, roles in growth stimulator y processes have also been implied. To determine whether there are any functional interactions between E1A 12S and the E1B 55K and 19K polyp eptides, primary epithelial cells were infected with 12S viruses with different E1B regions. In the absence of both E1B proteins, there was an increase in 12S expression. This resulted in increased levels of DN A synthesis, entry into S-phase of the cell cycle and increased levels of proliferation, in the presence or absence of serum. There was also a higher induction of growth factor activity. In the presence of the 55K and absence of the 19K protein, there was a decrease in 12S expres sion. However, the highest induction of proliferative responses was ob served. This suggests that expression of the 19K polypeptide inhibits 12S function directly. The lack of 19K expression also enabled the epi thelial cells to have a much higher plating efficiency, achieve a grea ter cell density and reach the immortalized state faster. Although som e modest differences in p53 expression were observed when compared to mock, they could not be correlated with any phenotype.