Linked Life Data

10365915

Source:http://linkedlifedata.com/resource/pubmed/id/10365915

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-6-21
pubmed:abstractText
We previously demonstrated a correlation between wild-type p53 expression and appearance of osteoblastic-specific differentiation characteristics, as evidenced by basal osteocalcin gene expression in a mouse osteosarcoma tumor. The study reported here further explored the possibility of p53's having a distinct transcription-activating role in bone differentiation, in addition to its proposed role in G1 arrest and apoptosis. ROS17/2.3 osteoblastic osteosarcoma cells were stably transfected with a plasmid containing wild-type p53 binding sequences fused to the chloramphenicol acetyltransferase reporter gene. These cells were used to determine the transactivating role of p53 in regulation of osteocalcin gene expression. We chose two conditions under which osteocalcin expression is known to be upregulated: exposure of osteoblastic cells to differentiation-promoting medium and to vitamin D3. Exposure of the transfected cells to differentiation-promoting medium produced an increase in p53 transactivating activity correlating with the appearance of osteocalcin expression after about 1 wk. Vitamin D3 treatment resulted in upregulation of osteocalcin activity without a corresponding change in p53 transactivation activity or expression. In separate experiments, we tested whether changes in osteocalcin expression accompanied changes in p53 activity under conditions of downregulation of cell proliferation mediated by inhibition of DNA synthesis. Hydroxyurea treatment was used to inhibit DNA synthesis and produce growth arrest in osteoblastic cells. Inhibition of osteoblast cell proliferation was associated with a fourfold increase in p53 transactivating activity and a transient increase in osteocalcin steady-state expression. These results demonstrated a close relationship between p53 and osteocalcin and suggested a regulatory role for wild-type p53 in the control of basal osteocalcin gene expression in osteoblasts.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0899-1987
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
132-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
p53 transactivity during in vitro osteoblast differentiation in a rat osteosarcoma cell line.
pubmed:affiliation
Department of Biochemistry, Midwestern University, Downers Grove, Illinois 60515, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't