Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2007-11-16
pubmed:abstractText
Aberrant activation of the phosphoinositide-3-kinase (PI3K)/PTEN/Akt pathway, leading to increased proliferation and decreased apoptosis, has been implicated in several human pathologies including cancer. Our previous data have shown that Akt-mediated signaling is an essential mediator in the mouse skin carcinogenesis system during both the tumor promotion and progression stages. In addition, overexpression of Akt is also able to transform keratinocytes through transcriptional and posttranscriptional processes. Here, we report the consequences of the increased expression of Akt1 (wtAkt) or constitutively active Akt1 (myrAkt) in the basal layer of stratified epithelia using the bovine keratin K5 promoter. These mice display alterations in epidermal proliferation and differentiation. In addition, transgenic mice with the highest levels of Akt expression developed spontaneous epithelial tumors in multiple organs with age. Furthermore, both wtAkt and myrAkt transgenic lines displayed heightened sensitivity to the epidermal proliferative effects of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and heightened sensitivity to two-stage skin carcinogenesis. Finally, enhanced susceptibility to two-stage carcinogenesis correlated with a more sustained proliferative response following treatment with TPA as well as sustained alterations in Akt downstream signaling pathways and elevations in cell cycle regulatory proteins. Collectively, the data provide direct support for an important role for Akt signaling in epithelial carcinogenesis in vivo, especially during the tumor promotion stage.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10879-88
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Deregulated activity of Akt in epithelial basal cells induces spontaneous tumors and heightened sensitivity to skin carcinogenesis.
pubmed:affiliation
Molecular Oncology Unit, Division of Biomedicine, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural