Time-sensitive reversal of hyperplasia in transgenic mice expressing SV40 T antigen - PubMed (original) (raw)

Time-sensitive reversal of hyperplasia in transgenic mice expressing SV40 T antigen

D Ewald et al. Science. 1996.

Abstract

The role of viral oncoprotein expression in the maintenance of cellular transformation was examined as a function of time through controlled expression of simian virus 40 T antigen (TAg). Expression of TAg in the submandibular gland of transgenic mice from the time of birth induced cellular transformation and extensive ductal hyperplasia by 4 months of age. The hyperplasia was reversed when TAg expression was silenced for 3 weeks. When TAg expression was silenced after 7 months, however, the hyperplasia persisted even though TAg was absent. Although the polyploidy of ductal cells could be reversed at 4 months of age, cells at 7 months of age remained polyploid even in the absence of TAg. These results support a model of time-dependent multistep tumorigenesis, in which virally transformed cells eventually lose their dependence on the viral oncoprotein for maintenance of the transformed state.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances

LinkOut - more resources