Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
10
|
| pubmed:dateCreated |
1992-11-27
|
| pubmed:abstractText |
To challenge the theory of tissue specificity of tumor promoters, the biochemical and tumor promoting effects of okadaic acid (OA), a potent tumor promoter on mouse skin, were studied in the mucosa of rat glandular stomach. OA strongly inhibited protein phosphatases 1 and 2A, and increased 4-fold the phosphorylation of elongation factor 2 in vitro in the mucosa. Intubation of 10 micrograms (12.4 nmol) OA induced ornithine decarboxylase in the mucosa. Tumor promotion of OA was studied in the glandular stomach initiated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in a two-stage carcinogenesis experiment. OA in drinking water, 10 micrograms (12.4 nmol) per rat per day from weeks 9-55 of the experiment, and 20 micrograms (24.8 nmol) from weeks 56-72, significantly enhanced development of the neoplastic changes in the glandular stomach (P < 0.05). The neoplastic changes included adenomatous hyperplasias and adenocarcinomas, both of which correspond to papillomas and carcinomas in a two-stage mouse skin carcinogenesis experiment. The percentages of neoplastic change-bearing rats of the groups treated with MNNG plus OA, MNNG alone or OA alone were 75.0, 46.4 and 0% respectively. OA enhanced tumorigenesis in the MNNG-initiated glandular stomach of rats through the same mechanisms of action as in mouse skin. The OA pathway mediated through inhibition of protein phosphatases 1 and 2A is applicable to various organs as a general mechanism of tumor promotion.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Carcinogens,
http://linkedlifedata.com/resource/pubmed/chemical/Ethers, Cyclic,
http://linkedlifedata.com/resource/pubmed/chemical/Methylnitronitrosoguanidine,
http://linkedlifedata.com/resource/pubmed/chemical/Okadaic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Ornithine Decarboxylase,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoprotein Phosphatases
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0143-3334
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
13
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1841-5
|
| pubmed:dateRevised |
2007-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:1330344-Animals,
pubmed-meshheading:1330344-Body Weight,
pubmed-meshheading:1330344-Carcinogens,
pubmed-meshheading:1330344-Enzyme Induction,
pubmed-meshheading:1330344-Ethers, Cyclic,
pubmed-meshheading:1330344-Female,
pubmed-meshheading:1330344-Gastric Mucosa,
pubmed-meshheading:1330344-Male,
pubmed-meshheading:1330344-Methylnitronitrosoguanidine,
pubmed-meshheading:1330344-Okadaic Acid,
pubmed-meshheading:1330344-Organ Specificity,
pubmed-meshheading:1330344-Ornithine Decarboxylase,
pubmed-meshheading:1330344-Phosphoprotein Phosphatases,
pubmed-meshheading:1330344-Rats,
pubmed-meshheading:1330344-Rats, Inbred F344,
pubmed-meshheading:1330344-Rats, Sprague-Dawley,
pubmed-meshheading:1330344-Stomach,
pubmed-meshheading:1330344-Stomach Neoplasms
|
| pubmed:year |
1992
|
| pubmed:articleTitle |
An alternative theory of tissue specificity by tumor promotion of okadaic acid in glandular stomach of SD rats.
|
| pubmed:affiliation |
National Cancer Center Research Institute, Tokyo, Japan.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|