TAT-RasGAP317-326 requires p53 and PUMA to sensitize tumor cells to genotoxins
Details
Serval ID
serval:BIB_72E6D50C6000
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
TAT-RasGAP317-326 requires p53 and PUMA to sensitize tumor cells to genotoxins
Journal
Molecular Cancer Research
ISSN
1541-7786 (Print)
Publication state
Published
Issued date
05/2007
Volume
5
Number
5
Pages
497-507
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May
Research Support, Non-U.S. Gov't --- Old month value: May
Abstract
Although chemotherapy has revolutionized cancer treatment, the associated side effects induced by lack of specificity to tumor cells remain a challenging problem. We have previously shown that TAT-RasGAP(317-326),a cell-permeable peptide derived from RasGAP, specifically sensitizes cancer cells to the action of genotoxins. The underlying mechanisms of this sensitization were not defined however. Here, we report that TAT-RasGAP(317-326) requires p53, but not the Ras effectors Akt and extracellular signal-regulated kinase, to mediate its tumor sensitization abilities. The TAT-RasGAP(317-326) peptide, although not modulating the transcriptional activity of p53 or its phosphorylation and acetylation status, nevertheless requires a functional p53 cellular status to increase the sensitivity of tumor cells to genotoxins. Genes regulated by p53 encode proapoptotic proteins, such as PUMA, and cell cycle control proteins, such as p21. The ability of TAT-RasGAP(317-326) to sensitize cancer cells was found to require PUMA but not p21. TAT-RasGAP(317-326) did not affect PUMA levels, however, but increased genotoxin-induced mitochondrial depolarization and caspase-3 activation. These results indicate that TAT-RasGAP(317-326) sensitizes tumor cells by activating signals that intersect with the p53 pathway downstream of, or at the level of, proapoptotic p53 target gene products to increase the activation of the mitochondrial death pathway.
Keywords
Acetylation/drug effects
Apoptosis/drug effects
Apoptosis Regulatory Proteins/*metabolism
Cell Line, Tumor
Cisplatin/pharmacology
Cyclin-Dependent Kinase Inhibitor p21/metabolism
Enzyme Activation/drug effects
Extracellular Signal-Regulated MAP Kinases/metabolism
Gene Products, tat/chemistry/*pharmacology
HCT116 Cells
Humans
MAP Kinase Signaling System/drug effects
Mutagens/*pharmacology
Neoplasms/metabolism/*pathology
Peptides/pharmacology
Phosphorylation/drug effects
Proto-Oncogene Proteins/*metabolism
Proto-Oncogene Proteins c-akt/metabolism
Thermodynamics
Transcription, Genetic/drug effects
Tumor Suppressor Protein p53/genetics/*metabolism
ras GTPase-Activating Proteins/chemistry/*pharmacology
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 15:43
Last modification date
20/08/2019 15:31