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- W1524163930 abstract "p53 is a potent tumour suppressor that is inactivated in the majority, if not all human cancers. In about 50% of the cases, the gene is mutated and in the rest it is rendered inactive mainly by deregulation of its negative regulators such as Hdm2 and HdmX. Targeting p53 has been shown to be a promising strategy to fight cancer and the first compounds reactivating p53 have reached the stage of clinical trials. In addition to immediate clinical use, compounds that activate p53 are valuable tools to increase the knowledge about fundamental p53 biology. RITA is an example for such a compound activating p53. We found that it induces decreased protein levels of the negative regulator of p53, HdmX, in a p53-dependent manner. This is mediated by ATM-induced phosphorylation. In addition expression of Wip1 is inhibited. Wip1 depletion is an important event for HdmX decrease, as Wip1 reverses ATM mediated phosphorylation and thus can prevent ATM-induced HdmX decline. The biological significance of HdmX and Wip1 inhibition is highlighted by the fact that a knockdown of either of them enhances cell killing by the p53-activating drugs RITA and nutlin3a. To get insight into mechanisms of p53 mediated transcriptional regulation, we compared genome-wide chromatin occupancy by p53 upon its activation by three different compounds, RITA, nutlin3a and 5-FU that cause different biological outcomes. We compared genome-wide chromatin occupancy by p53. Surprisingly, the regions that were bound by p53 to the highest extent were the same after all three treatments, despite their different biological outcomes. Comparison of the p53occupied sites with gene expression changes upon p53 activation by nutlin3a allowed identifying 280 previously unknown target genes. The common p53 binding motif is present much more frequently in the promoter region of induced genes than in that of repressed genes. This suggests different mechanisms for gene induction versus repression by p53, presumably distinguished by the involvement of cofactors. This is in line with our finding that binding sites for cofactors in the proximity of p53 sites are distinct for induced and repressed genes. We identified AURKA (Aurora kinase A) as a novel p53-repressed target gene, and found that STAT3 also regulates it, antagonising p53. Finally we found, that expression of our newly identified panel of p53 target genes correlated with the p53 status, the grade of tumours and the long-term survival in a set of 250 breast cancer patients. Malignant melanomas have very poor prognosis with extremely low long-term survival once the metastatic stage is reached. It has been shown that in 3-dimensional collagen type I matrix that mimics the microenvironment of the human dermis, melanoma cells induce integrin-dependent inactivation of p53, rescuing the cells from apoptosis. Thus, reactivation of p53 might be a promising strategy to kill melanoma cells. To test this, we treated melanoma cells that were grown in 3D conditions with the p53 reactivating compound PRIMA-1/APR-246. Indeed, this induced apoptosis in the cells in a p53 dependent manner. Consistently, the growth of melanoma xenografts in mice was suppressed in a p53-dependent manner after PRIMA-1 treatment. In summary, this thesis demonstrates examples for both the use of p53 activating compounds as research tools to uncover new details of p53 biology as well as their application for therapy, exemplified by effects of PRIMA-1 in malignant melanomas in vitro and in vivo. LIST OF PUBLICATIONS I. C. Spinnler, E. Hedstrom, H. Li, J. de Lange, F. Nikulenkov, A.F.A.S. Teunisse, M. Verlaan-de Vries, V. Grinkevich, A.G. Jochemsen, and G. Selivanova Abrogation of Wip1 expression by RITA-activated p53 potentiates apoptosis induction via activation of ATM and inhibition of HdmX Cell Death Differ; May 6, 2011; [Epub ahead of print]; II. F. Nikulenkov, C. Spinnler, C. Tonelli, M. Turunen, H. Li, T. Kivioja, A. Kel, J. Taipale, and G. Selivanova Using p53 activating drugs as tools to investigate p53's transcriptional programme in a high throughput approach Submitted manuscript III. W. Bao, M. Chen, X. Zhao, R. Kumar, C. Spinnler, M. Thullberg, N. Issaeva, G. Selivanova, and S. Stromblad PRIMA-1/APR-246 induces wild-type p53-dependent suppression of malignant melanoma tumor growth in 3D culture and in vivo Cell Cycle 10:2, 301-307; January 15, 2011;" @default.
- W1524163930 created "2016-06-24" @default.
- W1524163930 creator A5032904530 @default.
- W1524163930 date "2011-05-24" @default.
- W1524163930 modified "2023-09-27" @default.
- W1524163930 title "Small Molecules as Research Tools for Studying the Biology of the Tumour Suppressor p53" @default.
- W1524163930 cites W1482923899 @default.
- W1524163930 cites W148936752 @default.
- W1524163930 cites W1534987406 @default.
- W1524163930 cites W1546636359 @default.
- W1524163930 cites W1586543322 @default.
- W1524163930 cites W1591281137 @default.
- W1524163930 cites W1592021885 @default.
- W1524163930 cites W1640635403 @default.
- W1524163930 cites W1675096266 @default.
- W1524163930 cites W1677141414 @default.
- W1524163930 cites W1839476071 @default.
- W1524163930 cites W1927464414 @default.
- W1524163930 cites W1963972559 @default.
- W1524163930 cites W1965173366 @default.
- W1524163930 cites W1968075505 @default.
- W1524163930 cites W1973748124 @default.
- W1524163930 cites W1978782811 @default.
- W1524163930 cites W1979322770 @default.
- W1524163930 cites W1981979392 @default.
- W1524163930 cites W1982545718 @default.
- W1524163930 cites W1985064409 @default.
- W1524163930 cites W1986076152 @default.
- W1524163930 cites W1986245375 @default.
- W1524163930 cites W1986706321 @default.
- W1524163930 cites W1989936068 @default.
- W1524163930 cites W1992760686 @default.
- W1524163930 cites W1992947288 @default.
- W1524163930 cites W1993263392 @default.
- W1524163930 cites W1993597074 @default.
- W1524163930 cites W1993831923 @default.
- W1524163930 cites W1994394502 @default.
- W1524163930 cites W1995180922 @default.
- W1524163930 cites W1997222931 @default.
- W1524163930 cites W1997557358 @default.
- W1524163930 cites W1998297552 @default.
- W1524163930 cites W1999320089 @default.
- W1524163930 cites W1999330214 @default.
- W1524163930 cites W2002689109 @default.
- W1524163930 cites W2002705413 @default.
- W1524163930 cites W2004273407 @default.
- W1524163930 cites W2004311983 @default.
- W1524163930 cites W2006313701 @default.
- W1524163930 cites W2007023752 @default.
- W1524163930 cites W2007597782 @default.
- W1524163930 cites W2008301561 @default.
- W1524163930 cites W2010349266 @default.
- W1524163930 cites W2010370535 @default.
- W1524163930 cites W2011206688 @default.
- W1524163930 cites W2011361940 @default.
- W1524163930 cites W2011892634 @default.
- W1524163930 cites W2012053348 @default.
- W1524163930 cites W2013136213 @default.
- W1524163930 cites W2014938226 @default.
- W1524163930 cites W2016080258 @default.
- W1524163930 cites W2016107093 @default.
- W1524163930 cites W2018338006 @default.
- W1524163930 cites W2018383450 @default.
- W1524163930 cites W2018385269 @default.
- W1524163930 cites W2018653012 @default.
- W1524163930 cites W2019081978 @default.
- W1524163930 cites W2023971274 @default.
- W1524163930 cites W2025476423 @default.
- W1524163930 cites W2028178616 @default.
- W1524163930 cites W2028553570 @default.
- W1524163930 cites W2033787501 @default.
- W1524163930 cites W2039030772 @default.
- W1524163930 cites W2043912950 @default.
- W1524163930 cites W2044079387 @default.
- W1524163930 cites W2045786144 @default.
- W1524163930 cites W2046135777 @default.
- W1524163930 cites W2046419821 @default.
- W1524163930 cites W2047596219 @default.
- W1524163930 cites W2049271826 @default.
- W1524163930 cites W2049527615 @default.
- W1524163930 cites W2052556036 @default.
- W1524163930 cites W2056349777 @default.
- W1524163930 cites W2058624670 @default.
- W1524163930 cites W2058769115 @default.
- W1524163930 cites W2059787427 @default.
- W1524163930 cites W2060972565 @default.
- W1524163930 cites W2061658069 @default.
- W1524163930 cites W2062789389 @default.
- W1524163930 cites W2062953502 @default.
- W1524163930 cites W2063669247 @default.
- W1524163930 cites W2068389580 @default.
- W1524163930 cites W2072319696 @default.
- W1524163930 cites W2072491772 @default.
- W1524163930 cites W2072706757 @default.
- W1524163930 cites W2073576377 @default.
- W1524163930 cites W2076149108 @default.
- W1524163930 cites W2077858999 @default.
- W1524163930 cites W2079945282 @default.
- W1524163930 cites W2086042427 @default.
- W1524163930 cites W2088308108 @default.