Heat-shock responsive elements in the induction of the multidrug resistance gene (MDR1).
The MDR1 gene, considered to be involved in multidrug resistance of cancer cells, is expressed in liver, kidney, small intestine and the blood-brain barrier. We investigated MDR1 gene expression in the well-differentiated hepatoma cell line HepG2 after exposure to several stresses and found that sodium arsenite treatment increased MDR1 gene expression 2.6-fold. Deletion analysis of the MDR1 promoter indicated that the transcriptional activation after exposure to arsenite depends on a 60-bp region containing two heat-shock responsive elements.
Department of Agricultural Chemistry, Kyoto University, Japan.
N
N
Kioka
Y
Y
Yamano
T
T
Komano
K
K
Ueda
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004252:DNA Mutational Analysis; D004274:DNA, Recombinant / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006358:Hot Temperature; D008113:Liver Neoplasms / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004274:DNA, Recombinant; D008562:Membrane Glycoproteins; D015500:Chloramphenicol O-Acetyltransferase