This article is part of the supplement: The Third International Symposium on the Molecular Biology of Breast Cancer
Mutant p53 exerts its gain of function through activation of the NF-κB pathway
1 Department of Experimental Oncology, Regina Elena Cancer Institute, Rome, Italy
2 Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
3 Department of Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo, Norway
4 Laboratory of Receptor Biology & Gene Expression and DHHS/NIH/NCI/CCR, Bethesda, Maryland, USA
5 Department of Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, California, USA
6 Center for Advanced Biotechnology and Medicine, Piscataway, New Jersey, USA
7 Fondazione Andrea Cesalpino, University La Sapienza, Rome, Italy
8 University of Oslo, Faculty Division, The Norwegian Radium Hospital, Oslo, Norway
Breast Cancer Research 2005, 7(Suppl 2):P4.46 doi:10.1186/bcr1176
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| Published: | 17 June 2005 |
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Poster Presentation
The p53 gene is subject to frequent mutations in tumors, often leading to accumulation of excess mutant p53 protein, which can exhibit biological gain of function. In particular, mutant p53 exerts anti-apoptotic effects. Likewise, NF-κ B is a potent inhibitor of apoptosis, whose extended activation can promote cancer. We discovered that mutant p53 is in complex with the p65 NF-κ B subunit in tumor cells treated with TNF, a potent inducer of NF-κ B. In addition, we demonstrated that mutant p53 enhances the transcriptional activity of NF-κ B and its anti-apoptotic efficacy. Moreover, we were able to show that mutant p53 and NF-κ B are recruited together with the p300 acetyltransferase to anti-apoptotic target gene promoters. Interestingly, mutant p53 ablation attenuates the activity of NF-κ B and renders cancer cells susceptible to killing by TNF. Finally, we observed a close correlation between the high frequency of p53 mutations and the elevated expression of NF-κ B target genes in breast tumors. Therefore, our findings support an important role of NF-κ B in mediating the oncogenic activities of mutant p53 in tumor cells.