Rescue of mutants of the tumor suppressor p53 in cancer cells by a designed peptide

Proc Natl Acad Sci U S A. 2003 Nov 11;100(23):13303-7. doi: 10.1073/pnas.1835733100. Epub 2003 Oct 31.

Abstract

We designed a series of nine-residue peptides that bound to a defined site on the tumor suppressor p53 and stabilized it against denaturation. To test whether the peptides could act as chaperones and rescue the tumor-suppressing function of oncogenic mutants of p53 in living cells, we treated human tumor cells with the fluorescein-labeled peptide Fl-CDB3 (fluorescent derivative of CDB3). Before treatment, the mutant p53 in the cell was predominantly denatured. Fl-CDB3 was taken up into the cytoplasm and nucleus and induced a substantial up-regulation of wild-type p53 protein and representative mutants. The mutants, His-273 and His-175 p53, adopted the active conformation, with a dramatic decrease in the fraction of denatured protein. In all cases, there was p53-dependent induction of expression of the p53 target genes mdm2, gadd45, and p21, accompanied by p53-dependent partial restoration of apoptosis. Fl-CDB3 sensitized cancer cells that carried wild-type p53 to p53-dependent gamma-radiation-induced apoptosis. Although Fl-CDB3 did not elicit a full biological response, it did bind to and rescue p53 in cells and so can serve as a lead for the development of novel drugs for anticancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Cell Separation
  • Cytoplasm / metabolism
  • Epitopes
  • Flow Cytometry
  • Fluoresceins / pharmacology*
  • Fluorescent Dyes / pharmacology
  • Gamma Rays
  • Humans
  • Kinetics
  • Mutation
  • Oligopeptides / pharmacology*
  • Peptides / chemistry*
  • Peptides / pharmacology
  • Protein Conformation
  • Time Factors
  • Transcription, Genetic
  • Transcriptional Activation
  • Tumor Suppressor Protein p53 / genetics*
  • Tumor Suppressor Protein p53 / metabolism
  • Tumor Suppressor Protein p53 / physiology*
  • Up-Regulation

Substances

  • Epitopes
  • Fluoresceins
  • Fluorescent Dyes
  • Oligopeptides
  • Peptides
  • Tumor Suppressor Protein p53
  • fluoresceinyl-arginyl-glutamyl-aspartyl-glutamyl-aspartyl-glutamyl-isoleucyl-glutamyl-tryptophan