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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-2-2
pubmed:abstractText
The multidrug transporter, initially identified as a multidrug efflux pump responsible for resistance of cultured cells to natural product cytotoxic drugs, is normally expressed on the apical membranes of excretory epithelial cells in the liver, kidney, and intestine. This localization suggests that the multidrug transporter may have a normal physiological role in transporting cytotoxic compounds or metabolites. In the liver, hepatectomy or treatment with chemical carcinogens increases expression of the MDR1 gene which encodes the multidrug transporter. To evaluate conditions which increase MDR1 gene expression, we have investigated the induction of the MDR1 gene by physical and chemical environmental insults in the renal adenocarcinoma cell line HTB-46. There are two strong heat shock consensus elements in the major MDR1 gene promoter. Exposure of HTB-46 cells to heat shock, sodium arsenite, or cadmium chloride led to a 7- to 8-fold increase in MDR1 mRNA levels. MDR1 RNA levels did not change following glucose starvation or treatment with 2-deoxyglucose and the calcium ionophore A23187, conditions which are known to activate the expression of another family of stress proteins, the glucose-regulated proteins. The levels of the multidrug transporter, P-glycoprotein, as measured by immunoprecipitation, were also increased after heat shock and sodium arsenite treatment. This increase in the level of the multidrug transporter in HTB-46 cells correlated with a transient increase in resistance to vinblastine following heat shock and arsenite treatment. These results suggest that the MDR1 gene is regulatable by environmental stress.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:1967174-Adenocarcinoma, pubmed-meshheading:1967174-Arsenic, pubmed-meshheading:1967174-Arsenites, pubmed-meshheading:1967174-Base Sequence, pubmed-meshheading:1967174-Cadmium, pubmed-meshheading:1967174-Cadmium Chloride, pubmed-meshheading:1967174-Calcimycin, pubmed-meshheading:1967174-Deoxyglucose, pubmed-meshheading:1967174-Drug Resistance, pubmed-meshheading:1967174-Gene Expression, pubmed-meshheading:1967174-Heat-Shock Proteins, pubmed-meshheading:1967174-Hot Temperature, pubmed-meshheading:1967174-Humans, pubmed-meshheading:1967174-Kidney Neoplasms, pubmed-meshheading:1967174-Membrane Glycoproteins, pubmed-meshheading:1967174-Molecular Sequence Data, pubmed-meshheading:1967174-P-Glycoprotein, pubmed-meshheading:1967174-Promoter Regions, Genetic, pubmed-meshheading:1967174-RNA, Messenger, pubmed-meshheading:1967174-Tumor Cells, Cultured
pubmed:year
1990
pubmed:articleTitle
Heat shock and arsenite increase expression of the multidrug resistance (MDR1) gene in human renal carcinoma cells.
pubmed:affiliation
Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article