Linked Life Data

15075385

Source:http://linkedlifedata.com/resource/pubmed/id/15075385

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-7-19
pubmed:abstractText
One activity potentially limiting the efficacy of camptothecin anticancer agents is their cellular efflux by the ATP-binding cassette half-transporter, ABCG2. Homocamptothecins are novel anticancer drugs that inhibit topoisomerase 1 with a greater potency than camptothecins. Homocamptothecins differ from camptothecins by their E-ring, which is seven-membered instead of the six-membered ring of camptothecins. We report herein that, like camptothecins, homocamptothecin and its difluoro derivative BN80915 are substrates for ABCG2. However, the resistance of three selected cell lines overexpressing wild-type or mutant ABCG2 to homocamptothecin or BN80915 was less than resistance to SN-38 (7-ethyl-10-hydroxycamptothecin), indicating that both the seven-membered E-ring present in homocamptothecin and the A- and B-ring modifications present in SN-38 are involved in substrate recognition by ABCG2. HEK-293 cells transfected with vectors encoding wild-type or mutant ABCG2 were found to be less resistant to both homocamptothecins than to SN-38. However, transfectants overexpressing mutant ABCG2 had relative resistance values for homocamptothecin and BN80915 4- to 14-fold higher than cells expressing wild-type ABCG2, suggesting that the gain of function resulting from mutation at amino acid 482, although not affecting SN-38, extends to the homocamptothecins. Resistance was reversed by the ABCG2 inhibitor fumitremorgin C. BN80915 was 17-fold more potent than SN-38 in wild-type ABCG2-transfected cells, suggesting that BN80915 has the potential to overcome ABCG2-related resistance to SN-38, the active metabolite of CPT-11 (irinotecan).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
310
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
836-42
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
ABCG2 mediates differential resistance to SN-38 (7-ethyl-10-hydroxycamptothecin) and homocamptothecins.
pubmed:affiliation
Cancer Therapeutics Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bldg. 10 Rm. 12C103, Bethesda, MD 20892, USA. sebates@helix.nih.gov
pubmed:publicationType
Journal Article, Comparative Study