Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-10-14
pubmed:abstractText
Previously we demonstrated that multidrug-resistant (MDR) cancer cells have elevated levels of a glycosylated form of ceramide, glucosylceramide. Here we compared ceramide metabolism and ceramide toxicity in MCF-7 and in adriamycin-resistant (MCF-7-AdrR) human breast cancer cells. MCF-7-AdrR cells were resistant to C6-ceramide (1-10 microM); however, in MCF-7 cells treated with C6-ceramide, viability dropped sharply. Ceramide, when supplemented, was not metabolized by MCF-7 cells. In contrast, ceramide was efficiently converted to glucosylceramide by MCF-7-AdrR cells. Analysis of extracellular [3H]ceramide in radiolabeled cells showed that MCF-7-AdrR cells do not have an enhanced capacity to efflux ceramide compared with MCF-7 cells. Triphenylethylene anti-estrogens, known modulators of drug resistance, were effective inhibitors of ceramide conversion to glucosylceramide, suggesting that blocking ceramide metabolism plays a role in chemosensitization. The anti-progestine, RU486, also blocked glucosylceramide synthesis in cells; however, LY117018, a raloxifene analog, was without influence. We propose that an enhanced capacity to glycosylate ceramide as evidenced in MCF-7-AdrR cells, is a molecular determinant of drug resistance, particularly as regards resistance to ceramide-enhancing agents such as anthracyclines, ionizing radiation, and tumor necrosis factor-alpha.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1019-6439
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
535-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Ceramide toxicity and metabolism differ in wild-type and multidrug-resistant cancer cells.
pubmed:affiliation
John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, CA 90404, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't