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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1994-11-9
pubmed:abstractText
Mouse colon adenocarcinoma Co38 is widely used as a screening model for human colon tumors. To understand better the influence of tumor size on the main drug-metabolizing enzyme systems, we tested 15 mouse Co38 tumors at different sizes. The average weight was 917 +/- 444 mg (range, 300-1,400 mg). Cytochromes P-450 (1A1/1A2, 2B1/B2, 2C8-10, 2E1, 3A4), epoxide hydrolase (EH), and glutathione-S-transferases (GST-alpha, -mu, and -pi) were assayed by immunoblotting. The activities of the following enzymes or cofactors were determined by spectrophotometric or fluorometric assays: 1-chloro-2,4-dinitrobenzene-GST (CDNB-GST), selenium-independent glutathione peroxidase (GPX), 3,4-dichloronitrobenzene-GST (DCNB-GST), ethacrynic acid-GST (EA-GST), total glutathione (GSH), uridine diphosphate-glucuronosyltransferase (UDP-GT), beta-glucuronidase (beta G), sulfotransferase (ST), and sulfatase (S). Our results showed the absence of all probed P-450s and EH in Co38 tumors. No relationship was found between the Co38 tumor weights and GPX, GST-alpha, and EA-GST (regression analysis). However, a significant correlation was found between the tumor weights and all other enzymes investigated. For certain enzymes or cofactors, a linear decrease (P < 0.05) was observed as a function of tumor weight (CDNB-GST, DCNB-GST, GST-mu, GST-pi, GSH, and beta G). Other enzymatic activities (UDP-GT, S, and ST) were found to decrease in medium-size tumors and to increase in large tumors (P < 0.05; quadratic correlation). These data demonstrate that the expression of many drug-metabolizing enzyme systems is altered during tumor growth and suggest that tumoral response to chemotherapy could be altered as a function of tumor size.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0344-5704
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
497-502
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Influence of tumor size on the main drug-metabolizing enzyme systems in mouse colon adenocarcinoma Co38.
pubmed:affiliation
Département de Pharmaco-toxicologie et de Pharmacogénétique (CNRS URA 147), Institut Gustave-Roussy, Villejuif, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't