Galina Selivanova Group
p53 reinstatement leads to impressive regression of established tumors in mice, supporting the idea that restoring p53 is a good strategy in cancer treatment. My research focuses on the development of small molecules restoring the tumor suppression functions of p53, either by refolding mutant p53 to rescue its activity, or via preventing proteasomal degradation of p53 in tumors with non-mutated p53. One of our molecules, PRIMA-1MET, which can rescue the tumor suppressor function of mutant p53, is currently being tested in first-in-man Phase I clinical trial. We are addressing the fundamental question that need to be solved for the development of novel medicines, i.e. understanding of the mechanism of action of the candidate compounds, including target specificity in vitro and in vivo and possible off-target effects.
Ablation of key oncogenic pathways by RITAreactivated p53. We found a potent inhibition of crucial oncogenes by p53 upon reactivation by small molecule RITA using microarray analysis (left). Inhibition of oncogenes by p53 reduces the cells ability to buffer pro-apoptotic signals and elicits robust apoptosis (right).
Further, using small molecules as research tools, we address important questions of p53 biology. Applying systems biology we discovered important mechanisms which control the p53 choice between induction of apoptosis and growth arrest. We show that MDM2-dependent degradation of p53 cofactor hnRNP K and cdk inhibitor p21 switches the p53 response towards cell death (Enge et al., 2009). Further, we found that upon pharmacological activation, p53 unleashes a transcriptional repression of anti-apoptotic proteins Mcl-1, Bcl-2, MAP4, and survivin, blocks the Akt pathway, which is central in the transmission of growth regulatory signals originating from cell surface receptors and c-Myc oncogene on several levels and downregulates the oncogene product cyclin E and the transcription factor ²-catenin (Grinkevich et al., 2009). Our study adds a new dimension to p53 regulation of physiological events, demonstrating that p53 reactivation triggers ablation of crucial oncogenes. The multitude of oncogenes inhibited by p53 and multiple levels on which they are targeted create external robustness of the p53 response (see Figure for more details).
If you would like to learn more about our research (or just to drop in to say hello!) you are welcome to visit us at MTC, building F, level 6.
Visiting and Mailing Address
MTC, Box 280,
Nobels väg 16
S-171 77 Stockholm,
Project groups withing the Galina Selivanova group
Manipulation of the p53 tumor suppressor pathway : from lab bench to clinic
Half of human tumors carry mutations in the p53 gene, resulting in the expression of inactive protein. Tumors that do not carry p53 mutations, develop an alternative mechanisms of p53 inactivation, converging on enhanced proteasomal degradation. Given the extraordinary high frequency of p53 inactivation in tumors and the high potency of p53 in elimination of tumors, it appears highly desirable to restore the tumor suppressor function of p53 as a strategy to combat cancer.
We have identified a small molecule PRIMA-1 by screening the chemical library using cell-based assay. PRIMA-1 restores the active conformation to mutant p53 in cells and in vitro, re-activates the function of mutant p53 in tumor cells of different origin and suppreses the growth of human xenograft tumors in mice. Since around 50% of all human tumors carry mutations in p53, it could be widely applicable in clinic. This idea is now being tested in patients. Clinical trial with PRIMA-1 derivative PRIMA-1MET (commercial name Apr246) is currently on-going.
In tumors that retain wild type p53 its function is often impaired due to enhanced degradation by HDM-2. We have screened a chemical library and identified a small molecule, named RITA, which bound p53 and induced its accumulation in tumor cells. RITA prevents p53/HDM-2 interaction in vitro and in vivo and induces massive apoptosis in various tumor cells lines carrying wtp53 in vitro and in animal models. Notably, RITA does not suppress the growth of non-transformed cells, thus providing a convincing evidence that targeting p53 does not necessarily lead to the toxic effects in normal cells. RITA demonstrated substantial p53-dependent anti-tumor effect in vivo.
Prevention of p53/HDM2 interaction is regarded as a very promising strategy for anti-cancer treatment. Several big pharmaceutical companies are working on this approach, as for example Hoffman-La Roche, who identified HDM-2 inhibitor nutiln. Although both RITA and nutlin target HDM2/p53 interaction, their mechanism is different. Importantly, it appears that the spectrum of action is different, so that cell lines most sensitive to RITA are resistant to nutlin and vice versa. Thus, whereas the efforts of a number of labs and pharmaceutical companies are focused on inhibition of HDM-2, our studies identified a new target for pharmaceutical intervention, i.e., p53 itself, and demonstrated its feasibility and potency as a target. Our studies on small molecules reactivating p53 deepened our understanding of p53 functions and possibilities for its manipulation for cancer therapy.
In addition to applied aspects, we are actively working on important basic aspects of tumor biology, including genetic screens for p53 regulators and identification of novel factors which control p53 activity in tumor and in normal cells, which can serve as targets for therapeutic intervention in a future. In essence, to understand p53 is to understand how its interaction with proteins, and thus DNA, is controlled. We perform highly parallel and comprehensive search for p53 modulators by applying cutting-edge methodologies. We will chart p53-DNA and -protein interactions and identify their functional significance by inter-disciplinary integration of genome-wide expression profiling, ChIP-seq and proteomic approaches, followed by systems biology analysis. This will pave the way to the identification of key p53 target genes and factors contributing to alternative biological responses. These will be thoroughly validated in cells, mouse models and patient samples using functional genomics and protein-protein interaction assays. Selected factors will be used for chemical libraries screens to identify small molecules that target them. This will open the way for the development of novel therapeutic approaches.
Pharmacological reactivation of p53 as a strategy to treat cancer.
J. Intern. Med. 2015 Feb;277(2):248-59
The conserved Trp114 residue of thioredoxin reductase 1 has a redox sensor-like function triggering oligomerization and crosslinking upon oxidative stress related to cell death.
Cell Death Dis 2015 Jan;6():e1616
Modulation of the poly (ADP-ribose) polymerase inhibitor response and DNA recombination in breast cancer cells by drugs affecting endogenous wild-type p53.
Carcinogenesis 2014 Oct;35(10):2273-82
Wild type p53 reactivation: from lab bench to clinic.
FEBS Lett. 2014 Aug;588(16):2628-38
Integrated high-throughput analysis identifies Sp1 as a crucial determinant of p53-mediated apoptosis.
Cell Death Differ. 2014 Sep;21(9):1493-502
ROS-dependent activation of JNK converts p53 into an efficient inhibitor of oncogenes leading to robust apoptosis.
Cell Death Differ. 2014 Apr;21(4):612-23
APR-246/PRIMA-1MET inhibits thioredoxin reductase 1 and converts the enzyme to a dedicated NADPH oxidase.
Cell Death Dis 2013 Oct;4():e881
Dual targeting of wild-type and mutant p53 by small molecule RITA results in the inhibition of N-Myc and key survival oncogenes and kills neuroblastoma cells in vivo and in vitro.
Clin. Cancer Res. 2013 Sep;19(18):5092-103
Insights into p53 transcriptional function via genome-wide chromatin occupancy and gene expression analysis.
Cell Death Differ. 2012 Dec;19(12):1992-2002
Protein kinase Cα (PKCα) regulates p53 localization and melanoma cell survival downstream of integrin αv in three-dimensional collagen and in vivo.
J. Biol. Chem. 2012 Aug;287(35):29336-47
A novel facet of tumor suppression by p53: Induction of tumor immunogenicity.
Oncoimmunology 2012 Jul;1(4):541-543
Pharmacological activation of p53 triggers anticancer innate immune response through induction of ULBP2.
Cell Cycle 2011 Oct;10(19):3346-58
Inhibition of glycolytic enzymes mediated by pharmacologically activated p53: targeting Warburg effect to fight cancer.
J. Biol. Chem. 2011 Dec;286(48):41600-15
Abrogation of Wip1 expression by RITA-activated p53 potentiates apoptosis induction via activation of ATM and inhibition of HdmX.
Cell Death Differ. 2011 Nov;18(11):1736-45
PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53.
Clin. Cancer Res. 2011 May;17(9):2830-41
PRIMA-1Met/APR-246 induces wild-type p53-dependent suppression of malignant melanoma tumor growth in 3D culture and in vivo.
Cell Cycle 2011 Jan;10(2):301-7
Rescue of the apoptotic-inducing function of mutant p53 by small molecule RITA.
Cell Cycle 2010 May;9(9):1847-55
Rescue of p53 function by small-molecule RITA in cervical carcinoma by blocking E6-mediated degradation.
Cancer Res. 2010 Apr;70(8):3372-81
Therapeutic targeting of p53 by small molecules.
Semin. Cancer Biol. 2010 Feb;20(1):46-56
Integrins and mutant p53 on the road to metastasis.
Cell 2009 Dec;139(7):1220-2
p53-dependent inhibition of TrxR1 contributes to the tumor-specific induction of apoptosis by RITA.
Cell Cycle 2009 Nov;8(21):3584-91
HIPK2 regulation by MDM2 determines tumor cell response to the p53-reactivating drugs nutlin-3 and RITA.
Cancer Res. 2009 Aug;69(15):6241-8
Ablation of key oncogenic pathways by RITA-reactivated p53 is required for efficient apoptosis.
Cancer Cell 2009 May;15(5):441-53
Tumor-specific induction of apoptosis by a p53-reactivating compound.
Exp. Cell Res. 2009 Feb;315(3):451-61
Hypoxia induces p53-dependent transactivation and Fas/CD95-dependent apoptosis.
Cell Death Differ. 2007 Mar;14(3):411-21
Kaposi's sarcoma herpesvirus load in biopsies of cutaneous and oral Kaposi's sarcoma lesions.
Eur. J. Cancer 2007 Aug;43(12):1877-82
HAMLET triggers apoptosis but tumor cell death is independent of caspases, Bcl-2 and p53.
Apoptosis 2006 Feb;11(2):221-33
PRIMA-1 induces apoptosis in acute myeloid leukaemia cells with p53 gene deletion.
Br. J. Haematol. 2006 Jan;132(2):230-6
The structure of p53 tumour suppressor protein reveals the basis for its functional plasticity.
EMBO J. 2006 Nov;25(21):5191-200
Reactivation of mutant p53 and induction of apoptosis in human tumor cells by maleimide analogs.
J. Biol. Chem. 2005 Aug;280(34):30384-91
915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons.
Bioelectromagnetics 2005 Apr;26(3):173-84
PRIMA-1(MET) synergizes with cisplatin to induce tumor cell apoptosis.
Oncogene 2005 May;24(21):3484-91
HHV-8/KSHV during the development of Kaposi's sarcoma: evaluation by polymerase chain reaction and immunohistochemistry.
J. Cutan. Pathol. 2005 Jan;32(1):21-7
Dose-response for radiation-induced apoptosis, residual 53BP1 foci and DNA-loop relaxation in human lymphocytes.
Int. J. Radiat. Biol. 2005 Feb;81(2):125-38
|Michelle Da Silva Liberio||Postdoc|
|Gema Sanz Santos||Postdoc|
|Madhurendra Singh||Associated, Postdoc|
|Jiawei Zhu||Graduate Student|
Networks in Academia and Industry
Professor Joakim Lundeberg
On DNA microarray analysis of gene expression profiles induced by small molecules reactivating p53 in human tumor cells
Professor Sir Alan Fersht
on structural studies of the complexes between p53 protein and p53-reactivating compounds PRIMA-1, RITA, and MITA
Department of Chemistry University of Cambridge
Cambridge CB2 1EW, U.K.
Professor Taylor Jacks
on validation of PRIMA-1 in mutant p53 transgenic mouse models
Work: +1 (617) 253-0262
Fax: +1 (617) 253 9863
Howard Hughes Medical Inst.; Director, Center for Cancer Research,
Massachusetts Institute of Technology 77 Massachusetts Ave,
Rm.517A, Bldg. E17 Cambridge
MA 02139, USA
Professor Jiri Bartek
on molecular mechanisms of p53 activation in response to DNA damage
Department of Cell Cycle & Cancer
Institute of Cancer Biology Danish Cancer Society
Strandboulevarden 49 DK-2100
on molecular pathways of p53 regulation of metastasis-promoting factor Mts-1
Department of Molecular Cancer Biology
Institute of Cancer Biology Danish Cancer Society
Strandboulevarden 49 DK-2100
- EU FP 6: Intergrated Project 'Mutant p53 as target for anticancer therapy'. Consortium involves 20 groups and 3 SME from 11 European countries.
- EU FP6: Integrated Project 'Manipulating tumor suppression: a key to improve cancer treatment'. This consortium involves 19 partners and 2 SME from 10 European countries.
- APREA AB, Fogdevreten 2A, 17177 Stockholm, is a biotech company which is working on further improvement of the compounds we have identified, using medicinal chemistry and novel screenings.
Swedish Cancer Society (Cancerfonden)
Swedish Research Council (Vetenskapsrådet, VR)
Graduate Research School in Genomics and Bioinformatics (Forskarskolan i Genomik och Bioinformatik, FGB)
Cancer Society of Stockholm (Cancerföreningen i Stockholm)
Royal Academy of Sciences (Kungliga Vetenskapsakademien, KVA)
Marina Protopopova's PhD defense (Pdf file, 615 Kb)
Natalia's PhD defense (Pdf file, 529 Kb)
Christmas Dinner 2004 (Pdf file, 403 Kb)
Group trip to Rome 2005 (Pdf file, 2 Mb)
p53 workshop in New York 2006 (Pdf file, 1 Mb)
Madrid 2006: Martin's wedding (Pdf file, 909 Kb)