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

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.

• Authors: Natalia Issaeva, Assaf Friedler, Przemyslaw Bozko, Klas G Wiman, Alan R Fersht, Galina Selivanova
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 100 Issue 23 Pg. 13303-7 (Nov 11 2003) ISSN: 0027-8424 [Print] United States
• PMID: 14595027 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

• 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, pharmacology)
• Protein Conformation
• Time Factors
• Transcription, Genetic
• Transcriptional Activation
• Tumor Suppressor Protein p53 (genetics, metabolism, physiology)
• Up-Regulation