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Glutathione content and glutathione-S-transferase expression in 1,3-bis(2-chloroethyl)-1-nitrosourea-resistant human malignant astrocytoma cell lines.

Publication ,  Journal Article
Ali-Osman, F; Stein, DE; Renwick, A
Published in: Cancer Res
November 1, 1990

gamma-L-glutamyl-L-cysteinylglycine (GSH) has been shown to inactivate 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and quench DNA crosslink precursors of BCNU. Because of the central role of 2-chloroethyl-nitrosoureas in brain tumor chemotherapy, we investigated the intracellular GSH content and the expression of specific glutathione-S-transferases (GSTs) in three human malignant astrocytoma cell lines (UWR1, UWR2, and UWR3) of varying BCNU resistance to determine the interrelationship of these parameters with brain tumor BCNU resistance. GSH was assayed by ion-exchange high performance liquid chromatography after derivatization with 1-fluoro-2,4 dinitrobenzene. Both bulk and specific GST (acid, near-neutral, and basic) activities were examined using substrates that show high specificities to the different GSTs. Western blot analyses with antisera against GST-alpha, -mu, and -tau subunits were also performed on partially purified GST from the cells of each cell line. The results showed GSH content of 91, 46.5, and 28.3 nmol GSH/mg protein for UWR1, UWR2, and UWR3, respectively. Bulk GST activity (with 1-chloro-2,4-dinitrobenzene as substrate) also correlated with increasing BCNU resistance. Of the three GST classes examined by both substrate specificities and Western blotting, only the expression of the acidic form, GST-tau, correlated significantly with the rank order of BCNU resistance of the cell lines. GST-mu and -alpha were present in only trace amounts in all three cell lines.

Duke Scholars

Published In

Cancer Res

ISSN

0008-5472

Publication Date

November 1, 1990

Volume

50

Issue

21

Start / End Page

6976 / 6980

Location

United States

Related Subject Headings

  • Tumor Cells, Cultured
  • Substrate Specificity
  • Sodium Dodecyl Sulfate
  • Oncology & Carcinogenesis
  • Humans
  • Glutathione Transferase
  • Glutathione Disulfide
  • Glutathione
  • Electrophoresis, Polyacrylamide Gel
  • Drug Resistance
 

Published In

Cancer Res

ISSN

0008-5472

Publication Date

November 1, 1990

Volume

50

Issue

21

Start / End Page

6976 / 6980

Location

United States

Related Subject Headings

  • Tumor Cells, Cultured
  • Substrate Specificity
  • Sodium Dodecyl Sulfate
  • Oncology & Carcinogenesis
  • Humans
  • Glutathione Transferase
  • Glutathione Disulfide
  • Glutathione
  • Electrophoresis, Polyacrylamide Gel
  • Drug Resistance