Mutations within the p53 gene leading to accumulation of non-functional faulty protein occur in nearly 50% of cancer cases. Loss of p53 function results in abrogation of suicidal programs that produce genetic stability and intrinsic anticancer defense, opening the way for uncontrolled proliferation and malignant progression of cancer cells. Meanwhile, in the cells harboring structural defects within the p53 gene, the other components of the p53 pathway usually remain intact, leaving tumor cells highly sensitive to reintroduced wild-type p53. Theoretically, the impaired activity of mutant p53 protein could be pharmacologically corrected by small molecules, which induce a therapeutic effect. In a preliminary study, a set of small molecules that restore transcriptional activity of the His273 p53 mutant was obtained by high throughput screening of a chemical library in a cell-based readout. Some of the compounds show His273 p53 mutant-dependent growth suppressing and pro-apoptotic activity, and reduced growth of xenografts of A431 cell in nude mice.
In Aim 1 of the proposed program, we shall identify small molecules that reactivate transcriptional activity of several classes of p53 mutants in the context of human tumor cells by analyzing results of additional ongoing screenings. These compounds will be classified according to chemical similarity, spectrum of activity toward different classes of p53 mutants, and differences in the mechanisms of action. Detailed characterization of changes within the p53 pathway, caused by the p53-reactivating compounds, and their mechanisms of action will be challenged in Aim 2 of the program.
Aim 3 is designed to evaluate therapeutic potentials of restored p53 pathways in human tumor cells bearing mutant p53. Reactivation of p53 pathways will be achieved both by conditional expression of the wild-type p53, and by chemical reactivators of mutant p53 obtained in the course of the project. Optimal combinations of restored p53 activity with other therapeutic treatments will be found to ensure prevalence of cytotoxicity over cytostatic effects. These studies will be conducted both in vitro and in tumor xenografts. Approaches for modulation of the p53-dependnet response in human tumor cells will be developed and experimentally tested. Upon the completion of the project, novel potential classes of anticancer drugs that convert mutant p53 into a therapeutic will be suggested, and therapeutic potentials of restored mutant p53 will be evaluated.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA104903-02
Application #
6916567
Study Section
Drug Discovery and Molecular Pharmacology Study Section (DMP)
Program Officer
Blair, Donald G
Project Start
2004-07-01
Project End
2009-04-30
Budget Start
2005-07-01
Budget End
2006-04-30
Support Year
2
Fiscal Year
2005
Total Cost
$313,650
Indirect Cost
Name
Cleveland Clinic Lerner
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
135781701
City
Cleveland
State
OH
Country
United States
Zip Code
44195
Guryanova, Olga A; Drazba, Judith A; Frolova, Elena I et al. (2011) Actin cytoskeleton remodeling by the alternatively spliced isoform of PDLIM4/RIL protein. J Biol Chem 286:26849-59
Zheltukhin, A O; Chumakov, P M (2010) Constitutive and induced functions of the p53 gene. Biochemistry (Mosc) 75:1692-721
Khutornenko, Anastasia A; Roudko, Vladimir V; Chernyak, Boris V et al. (2010) Pyrimidine biosynthesis links mitochondrial respiration to the p53 pathway. Proc Natl Acad Sci U S A 107:12828-33
Chumakov, Stepan P; Kravchenko, Julia E; Prassolov, Vladimir S et al. (2010) Efficient downregulation of multiple mRNA targets with a single shRNA-expressing lentiviral vector. Plasmid 63:143-9
Olovnikov, Ivan A; Kravchenko, Julia E; Chumakov, Peter M (2009) Homeostatic functions of the p53 tumor suppressor: regulation of energy metabolism and antioxidant defense. Semin Cancer Biol 19:32-41
Chumakov, S P; Il'inskaia, G V; Kravchenko, Iu E et al. (2008) [A lentivirus vector based assay system for quantitative detection of intracellular translocations of recombinant proteins] Mol Biol (Mosk) 42:1004-11
Kravchenko, J E; Ilyinskaya, G V; Komarov, P G et al. (2008) Small-molecule RETRA suppresses mutant p53-bearing cancer cells through a p73-dependent salvage pathway. Proc Natl Acad Sci U S A 105:6302-7
Kochetkov, D V; Il'inskaia, G V; Komarov, P G et al. (2007) [Transcriptional inhibition of human papilloma virus in cervical carcinoma cells reactivates functions of the tumor suppressor p53] Mol Biol (Mosk) 41:515-23
Chumakov, P M (2007) Versatile functions of p53 protein in multicellular organisms. Biochemistry (Mosc) 72:1399-421
Egorov, E E; Moldaver, M V; Vishniakova, Kh S et al. (2007) [Enhanced control of proliferation in telomerized cells] Ontogenez 38:105-19

Showing the most recent 10 out of 19 publications