Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1992-8-25
pubmed:abstractText
P-Glycoprotein (Pgp) expression in cell lines derived from tumors arising from cells which normally express Pgp can be increased by sodium butyrate and other differentiating agents. Although the Pgp level increased 25-fold after sodium butyrate treatment in SW620 human colon carcinoma cells, the intracellular accumulation of vinblastine, adriamycin, and actinomycin D increased rather than decreased. In contrast, colchicine showed the expected decrease in accumulation, as a result of increased efflux. Likewise, treatment of a Pgp-expressing multidrug-resistant SW620 subline with sodium butyrate resulted in active interference with Pgp function. This effect was partially reversed by phorbol esters with a resulting decrease in the accumulation of vinblastine, adriamycin, and actinomycin D. Sodium butyrate, while increasing Pgp levels, inhibited the phosphorylation of Pgp. Time course studies revealed a tight relationship between decreased Pgp phosphorylation and increased vinblastine accumulation after sodium butyrate treatment. Either treatment with phorbol esters or withdrawal of sodium butyrate increased Pgp phosphorylation while decreasing vinblastine accumulation. These studies suggest that the specificity of Pgp transport can be modulated by phosphorylation and that vinblastine, adriamycin, or actinomycin D transport, but not that of colchicine, is diminished after dephosphorylation by sodium butyrate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6366-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Modulation of P-glycoprotein phosphorylation and drug transport by sodium butyrate.
pubmed:affiliation
Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article, In Vitro