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9-Hydroxyellipticine alters the conformation and DNA binding characteristics of mutated p53 protein

E Sugikawa1, S Tsunoda, N Nakanishi

  • 1Discovery Research Laboratory, Tanabe Seiyaku Co., Ltd., Toda, Saitama, Japan.

Anticancer Research
|November 29, 2001
PubMed

Insights

The cytotoxic agent 9-hydroxyellipticine (9HE) restores tumor suppressor protein p53

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • The tumor suppressor protein p53 is crucial for preventing cancer.
  • Mutations in p53 are common in human cancers, leading to loss of its tumor-suppressing functions.
  • Restoring p53 function is a key therapeutic goal in cancer treatment.

Purpose of the Study:

  • To investigate the effect of 9-hydroxyellipticine (9HE) on the tertiary structure and DNA binding of mutant p53.
  • To determine if 9HE can restore wild-type-like functions to mutated p53 proteins.

Main Methods:

  • Treatment of cancer cells with 9HE.
  • Analysis of p53 protein stability and degradation by calpain.
  • Assessment of p53 DNA binding affinity to a consensus sequence.

Main Results:

  • Mutant p53 proteins, normally resistant to calpain degradation, became sensitive after 9HE treatment.
  • 9HE treatment restored the ability of mutant p53 to bind to a wild-type p53 DNA consensus sequence.
  • Wild-type p53 showed consistent calpain sensitivity and DNA binding regardless of 9HE treatment.

Conclusions:

  • 9-hydroxyellipticine (9HE) alters the tertiary structure of mutant p53.
  • This structural change restores the DNA binding capacity of mutant p53, suggesting a potential therapeutic strategy for cancers with p53 mutations.

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