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O6-Methylguanine-DNA Methyltransferase (O6-MT) Activity as an Index of Drug Responsiveness to Antitumor Chloroethylnitrosoureas in Xenografted Brain Tumors

  • Katsuyoshi Mineura
  • Naoyuki Kuwahara
  • Katsuo Watanabe
  • Masayoshi Kowada

Abstract

The synthesized chloroethylnitrosoureas (CENUs), 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), and methyl-6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-α-D-glucopyranoside (MCNU), have been among the antitumor agents widely used for the treatment of malignant brain tumors [1]. Methods for monitoring responsiveness of brain tumors to CENUs on the basis of a cell-killing mechanism have been needed to enhance therapeutic effectiveness. It is well documented that a DNA repair enzyme O6-methylguanine-DNA methyltransferase (O6-MT), identical to the term O6-alkylguanine-DNA alkyltransferase, eliminates the O6-methylguanine induced by CENUs and reflects the cellular resistance to CENUs in cultured cell strains and xenografted tumors [2–5]. Further in vivo work was warranted to establish a chemoserisitivity index of O6-MT activity. In the present paper, we test the relationship of O6-MT activity and responsiveness to CENUs in xenografted brain tumors.

Keywords

Antitumor Agent Crude Protein Extract Coop Treatment Maximum Inhibition Rate Xenografted Brain Tumor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Tokyo 1991

Authors and Affiliations

  • Katsuyoshi Mineura
  • Naoyuki Kuwahara
  • Katsuo Watanabe
  • Masayoshi Kowada
    • 1
  1. 1.Neurosurgical ServiceAkita University HospitalAkita, 010Japan

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