Previous Article | Next Article ![]()
Mol. Cell. Biol., 08 1996, 4504-4511, Vol 16, No. 8
R Johnson, B Spiegelman, D Hanahan and R Wisdom
ras is an important oncogene in experimental animals and humans. In
addition, activated ras proteins are potent inducers of the transcription
factor AP-1, which is composed of heterodimeric complexes of Fos and Jun
proteins. Together with the fact that deregulated expression of some AP-1
proteins can cause neoplastic transformation, this finding suggests that
AP-1 may function as a critical ras effector. We have tested this
hypothesis directly by analyzing the response to activated ras in cells
that harbor a null mutation in the c- jun gene. The transcriptional
response of AP-1-responsive genes to activated ras is severely impaired in
c-jun null fibroblasts. Compared with wild-type cells, the c-jun null cells
lack many characteristics of ras transformation, including loss of contact
inhibition, anchorage independence, and tumorigenicity in nude mice; these
properties are restored by forced expression of c-jun. Rare tumorigenic
variants of ras-expressing c-jun null fibroblasts do arise. Analysis of
these variants reveals a consistent restoration of AP-1 activity. The
results provide genetic evidence that c-jun is a crucial effector for
transformation by activated ras proteins.
Copyright © 1996, American Society for Microbiology
Cellular transformation and malignancy induced by ras require c-jun
Hormone Research Institute, University of California, San Francisco 94143, USA.
This article has been cited by other articles:
B Activation to Suppress p53-Independent Apoptosis Induced by Oncogenic Ras. Science
278: 1812-1815
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»