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Cell death due to ACNU-induced DNA fragmentation: inhibition by cycloheximide

T Kobayashi1, T Tominaga, T Yoshimoto

  • 1Department of Neurosurgery, Tohoku University School of Medicine, Sendai, Japan.

Journal of Neuro-Oncology
|January 1, 1994
PubMed

Insights

Anticancer drug ACNU triggers programmed cell death in glioma cells via DNA fragmentation. This process, dependent on protein synthesis, occurs before cell membrane damage, suggesting a novel cell death pathway.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Anticancer drugs can induce apoptosis-like cell death.
  • Nitrosoureas are a class of anticancer agents.

Purpose of the Study:

  • To investigate the mechanism of cell death induced by ACNU.
  • To determine if ACNU-induced cell death involves apoptosis-like DNA fragmentation.

Main Methods:

  • Exposure of rat glioma cell line KEG-1 to ACNU.
  • Agarose gel electrophoresis to detect DNA fragmentation.
  • Trypan blue exclusion test for membrane integrity.
  • Use of cycloheximide (translational inhibitor) and actinomycin D (transcriptional inhibitor).
  • In vivo rat model with KEG-1 xenografts.

Main Results:

  • ACNU induced oligonucleosomal DNA fragmentation in KEG-1 cells.
  • DNA fragmentation preceded loss of membrane integrity.
  • Fragmentation was dose-dependent and inversely correlated with cell survival.
  • Cycloheximide suppressed DNA fragmentation and enhanced survival.
  • Actinomycin D did not inhibit fragmentation or enhance survival.
  • Similar cycloheximide-inhibitable DNA fragmentation observed in vivo.

Conclusions:

  • ACNU induces cell death associated with DNA fragmentation.
  • This process is partially dependent on protein synthesis.
  • ACNU may trigger a distinct apoptotic-like cell death pathway.

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