Linked Life Data

3141077

Source:http://linkedlifedata.com/resource/pubmed/id/3141077

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1988-12-9
pubmed:abstractText
Recent work from this laboratory has demonstrated the presence of a structurally and functionally different ornithine decarboxylase (ODC) in mouse epidermal tumors induced by a two-stage protocol involving initiation with 7,12-dimethylbenzanthracene (DMBA) and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA). In this report, the enzymatic properties of ODC present in DMBA-initiated chrysarobin-promoted papillomas are compared to the enzyme induced by chrysarobin in normal epidermis. Analyses of 13 individual tumor extracts indicated each had an elevated level of ODC activity compared to uninduced normal epidermis. Addition of GTP to the enzyme assay caused a marked stimulation of ODC activity in nine of 13 tumor extracts but had no effect on chrysarobin-induced epidermal ODC. Enzyme kinetic analyses indicated that GTP lowered the atypically high apparent Km values for L-ornithine of the papilloma enzyme to values typical of epidermal ODC. The K 1/2 for GTP activation of papilloma ODC was approximately 7 x 10(-9) M. When a series of nucleotides was tested, only GTP, the non-hydrolysable analog GTP gamma S, dGTP and GDP were capable of significant activation at 1 microM, while other derivatives including GMP, ATP and CTP were less effective. The ability of the tumor enzyme to bind GTP was confirmed by the results of GTP-agarose chromatography, in which the papilloma enzyme (but not chrysarobin-induced epidermal ODC) bound to this affinity column and could be eluted by GTP. While some differences were observed in the properties of ODC from chrysarobin-promoted versus TPA-promoted papillomas, the major conclusion of this study is that both agents cause the appearance of a functionally altered ODC in the majority of papillomas produced by a two-step protocol.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2081-5
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Presence of a functionally altered ornithine decarboxylase activity in chrysarobin-promoted mouse epidermal papillomas.
pubmed:affiliation
Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.