Linked Life Data

1868452

Source:http://linkedlifedata.com/resource/pubmed/id/1868452

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1991-9-13
pubmed:abstractText
Recent studies from our laboratory have demonstrated that dietary supplemental calcium had no significant effect on the incidence of 1,2-dimethylhydrazine-induced colonic tumors, but did decrease the number of rats with multiple tumors and reduced tumor size. Moreover, concomitant vitamin D deficiency appeared to abolish these protective effects of calcium on colonic tumors in this experimental model. To date, however, the mechanism(s) involved in these phenomena remain unclear. In order to address these important issues, 1,2-dimethylhydrazine-induced colonic tumors from animals on control, Ca(2+)-supplemented, vitamin D-sufficient, and Ca(2+)-supplemented, vitamin D-deficient diets were examined for the presence of ras oncogene mutations. DNA was extracted from each of these tumors. Targeted areas of K-ras and H-ras genes were amplified by the polymerase chain reaction and analyzed for point mutations using allele-specific oligonucleotide hybridization and subsequent DNA sequencing. The results of these studies demonstrated that: (a) approximately one-third of 1,2-dimethylhydrazine-induced colonic carcinomas in the control group had K-ras G to A mutations; (b) no mutations, however, were detected in the cancers of the calcium-supplemented group; (c) concomitant vitamin D deficiency abolished the antimutagenic effect of dietary calcium supplementation (e.g., approximately one-third of cancers in this group again had detectable K-ras mutations); and (d) no H-ras point mutations were detected in colonic tumors from any group. These findings suggest that alterations in K-ras mutations may be one possible mechanism by which calcium and vitamin D status influence colonic carcinogenesis in this experimental model.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
51
pubmed:geneSymbol
K-ras
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4305-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
K-ras mutations in 1,2-dimethylhydrazine-induced colonic tumors: effects of supplemental dietary calcium and vitamin D deficiency.
pubmed:affiliation
Pritzker School of Medicine, University of Chicago, Illinois 60637.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't