Identification of placental form of glutathione S-transferase in ACNU-resistant murine glioma cell lines.
Expression of the placental form of glutathione S-transferase (GST-P) in 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloro-ethyl)-3-nitrosourea hydrochloride (ACNU)-sensitive 9L and C6 glioma cells, and ACNU-resistant 9L (9LR) and C6 (C6R) glioma cells was investigated by Northern blot analysis for GST-P mRNA and Western blot analysis for GST-P protein. The sensitivity of 9L, 9LR, C6 and C6R cell lines to ACNU was evaluated by microculture tetrazolium assay. Localization of GSTP-P protein in these cell lines was investigated by immunocytochemical method. Expression level of GST-P mRNA in 9LR cells was 3 times that of 9L cells and the level of GST-P protein in 9LR cells was 1.7 times that of 9L cells. On the contrary, the amount of GST-P mRNA of C6R cells was 1.3-fold larger than C6 cells and that of GST-P protein of C6R cells was 1.3-fold larger than C6 cells. Immunocytochemical investigation revealed that 9LR cells had stronger expression of GST-P in their cytoplasm than 9L cells. Expression of GST-P in both C6R and C6 cells was less than 9L and 9LR cells, and the amount was similar to each other. The present study suggests that GST-P may play an important role in detoxification of anti-cancer drugs in some glioma cells.
Hara
A
A
Department of Neurosurgery, Gifu University School of Medicine, Japan.
Niikawa
S
S
Zhang
W
W
Sakai
N
N
Yamada
H
H
Yoshimi
N
N
Mori
H
H
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D004351:Drug Resistance; D005910:Glioma / Q000201:enzymology*; D005982:Glutathione Transferase / Q000378:metabolism*; D051379:Mice; D015376:Nimustine / Q000494:pharmacology*; D010920:Placenta / Q000201:enzymology*; D014407:Tumor Cells, Cultured
D015376:Nimustine; D005982:Glutathione Transferase