Linked Life Data

3840412

Source:http://linkedlifedata.com/resource/pubmed/id/3840412

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11 Pt 1
pubmed:dateCreated
1985-12-2
pubmed:abstractText
1 alpha,25-Dihydroxyvitamin D3 [1 alpha,25(OH)2D3], a hormonally active form of vitamin D3, was found to inhibit the promotional phase of 7,12-dimethylbenz[a]anthracene-induced skin carcinogenesis in female Sencar mice. Topical application of 1 alpha,25-(OH)2D3 once a week at a dose of 1 micrograms or less, a tolerable dose from hypercalcemia, dose dependently inhibited tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA). When 1 micrograms of 1 alpha,25(OH)2D3 was applied 30 min before 5 micrograms of TPA, the times required for 50 and 100% tumor incidence were delayed about 2.5 and 7 weeks, respectively, and the number of tumors per mouse was decreased by 25-30%. This inhibitory effect was more pronounced when examined by a two-stage promotion protocol, in which a single application of 5 micrograms of TPA (Stage I) was followed by repeated applications of 5 micrograms of mezerein once a week for 19 weeks (Stage II). When 1 alpha,25(OH)2D3 at 1 micrograms was applied at Stage I + II or Stage II, tumor formation was markedly suppressed, resulting in decrease of about 70-80% in the incidence and 87-90% in the number of tumors per mouse. Application of 1 alpha,25(OH)2D3 at Stage I only did not inhibit tumor formation, indicating that 1 alpha,25(OH)2D3 specifically inhibited Stage II promotion. These results are in good agreement with the previous and present findings that 1 alpha,25(OH)2D3 inhibited induction of epidermal ornithine decarboxylase by TPA and mezerein. The possibility that 1 alpha,25(OH)2D3 suppressed tumor promotion by killing initiated cells rather than inhibiting promotion was ruled out by an experiment in which TPA was applied to the 1 alpha,25(OH)2D3 alone-treated animals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5426-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Inhibition of tumor promotion in mouse skin by 1 alpha,25-dihydroxyvitamin D3.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't