Rescue of mutants of the tumor suppressor p53 in cancer cells by a designed peptide.
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.
Department of Oncology-Pathology, Cancer Center Karolinska, R8:00, Karolinska Institutet, Karolinska Hospital, SE-171 76 Stockholm, Sweden.
Natalia
N
Issaeva
Assaf
A
Friedler
Przemyslaw
P
Bozko
Klas G
KG
Wiman
Alan R
AR
Fersht
Galina
G
Selivanova
D017209:Apoptosis; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D002469:Cell Separation; D003593:Cytoplasm / Q000378:metabolism; D000939:Epitopes; D005434:Flow Cytometry; D005452:Fluoresceins / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000494:pharmacology; D005720:Gamma Rays; D006801:Humans; D007700:Kinetics; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D011487:Protein Conformation; D013997:Time Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D015854:Up-Regulation
D000939:Epitopes; D005452:Fluoresceins; D005456:Fluorescent Dyes; D009842:Oligopeptides; D010455:Peptides; D016159:Tumor Suppressor Protein p53; C479932:fluoresceinyl-arginyl-glutamyl-aspartyl-glutamyl-aspartyl-glutamyl-isoleucyl-glutamyl-tryptophan