Linked Life Data

9097977

Source:http://linkedlifedata.com/resource/pubmed/id/9097977

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-4-29
pubmed:abstractText
Aberrant crypt foci (ACF) are microscopic lesions which can be detected, after methylene blue staining, in the overtly normal looking colonic mucosa of cancer patients. ACF have been postulated to be precursor lesions which develop into colorectal cancer. Mutations of K-ras and p53 are two important genetic events implicated in colon carcinogenesis. Mutations in K-ras are detectable at earlier stages, while mutations in p53 are detectable at later stages of colon carcinogenesis. Our objective was to compare the nature of genetic alterations in K-ras (codon 12 and 13) and in p53 (exon 4-9) between ACF and corresponding colonic tumors from cancer patients. ACF with > or =20 crypts/focus were harvested from overtly normal looking colonic mucosa of cancer patients at a distance of (approx.) 5 cm from the site of colonic tumors. The colonic tumors and ACF samples were compared for K-ras codon 12 and 13 base pair sequence, using DNA sequencing and for p53 (exon 5-9) allelic types, using PCR-SSCP and DNA sequencing. The results demonstrated a perfect correlation in terms of the type of K-ras allele (wild or mutated) between the ACF (> or =20 crypts/focus) and corresponding colonic tumors in 11/13 cancer patients. Analyses of p53 mutations demonstrated the presence of p53 mutations in colonic carcinomas from 10/13 patients. However, p53 mutations could be detected in an ACF from only 1/13 patient. The results provides further evidence to the role of ACF as precursor to colon cancer. The presence of an identical K-ras as well as p53 mutation in an ACF and the corresponding colonic carcinoma in a patient suggests the possibility of existence of ACF that may be at a more advanced stage in the sequence of colonic tumorigenesis than others. In conclusion, the results suggest that a subset of ACF with higher multiplicity might be considered more likely to progress to more advanced lesions and should be explored as markers of colon cancer risk.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0304-3835
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-46
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
K-ras and p53 mutations in aberrant crypt foci and colonic tumors from colon cancer patients.
pubmed:affiliation
Institute for Chemoprevention Research, Plano, TX 75093, USA.
pubmed:publicationType
Journal Article