Drug resistance to cis-diamminedichloroplatinum (II) in Chinese hamster ovary cell lines transfected with glutathione S-transferase pi gene.
Establishment of Chinese hamster ovary (CHO) cell lines expressing human glutathione S-transferase-pi (GST-pi) was performed after cotransfection of pSV2-neo and human GST-pi cDNA-carrying plasmid p beta actGPi-2. About 30 G418-resistant clones were tested for their expression of GST-pi by Northern blot analysis. Two clones, beta 2-3 and beta 2-5, expressed a significant amount of GST-pi mRNA; and one clone, beta 1-1, that did not was also used for further study. Western blot analysis with anti-GST-pi antibody showed significant increases of GST-pi in beta 2-3 and beta 2-5, but not in beta 1-1. Northern blot analysis with the human GST-pi cDNA probe showed that the increase in the expression of GST-pi-mRNA in beta 2-3 and beta 2-5 was respectively 2- and 4-fold higher than that in beta 1-1. Southern blotting analysis showed that beta 1-1, beta 2-3 and beta 2-5 contained about one copy of the human GST-pi cDNA sequence. beta 2-3 and beta 2-5 were resistant to 1.4- and 3.0-fold higher doses of CDDP than CHO, respectively, but beta 1-1 was not. Increased expression of GST-pi might be associated with CDDP-resistance in CHO cells.
Miyazaki
M
M
Department of Biochemistry, Oita Medical School, Japan.
Kohno
K
K
Saburi
Y
Y
Matsuo
K
K
Ono
M
M
Kuwano
M
M
Tsuchida
S
S
Sato
K
K
Sakai
M
M
Muramatsu
M
M
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D003600:Cytosol / Q000201:enzymology; D015342:DNA Probes; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D005796:Genes; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D015151:Immunoblotting; D007700:Kinetics; D010053:Ovary; D014162:Transfection
D015342:DNA Probes; D005982:Glutathione Transferase; D002945:Cisplatin