Increased K-ras protein and activity in mouse and human lung epithelial cells at confluence.

TitleIncreased K-ras protein and activity in mouse and human lung epithelial cells at confluence.
Publication TypeJournal Article
Year of Publication2002
JournalCell growth & differentiation : the molecular biology journal of the American Association for Cancer Research
Volume13
Issue9
Pagination441-8
ISSN1044-9523
Abstract

Although K-ras is frequently mutated in lung adenocarcinomas, the normal function of K-ras p21 in lung is not known. In two mouse (E10 and C10) and one human (HPL1D) immortalized lung cell lines from peripheral epithelium, we have measured total K-ras p21 and active K-ras p21-GTP during cell proliferation and at growth arrest caused by confluence. In all three cell types, total K-ras p21 increased 2- to 4-fold at confluence, and active K-ras p21-GTP increased 10- to 200-fold. It was estimated that 0.03% of total K-ras p21 was in the active GTP-bound state at 50% confluence, compared with 1.4% at postconfluence. By contrast, stimulation of proliferation by serum-containing medium did not involve K-ras p21 activation, even though a rapid, marked activation of both Erk1/2 and Akt occurred. At confluence, large increases, up to 14-fold, were seen in Grb2/Sos1 complexes, which may activate K-ras p21. In sum, increased protein expression and activity of K-ras p21 are associated with growth arrest, not with proliferation, in mouse and human lung cell lines.

URLhttp://cgd.aacrjournals.org/cgi/pmidlookup?view=long&pmid=12354753
Short TitleCell Growth Differ
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