Abstract

Triple negative breast cancer (TNBC) is an aggressive subset for which effective therapeutic approaches are needed. A significant proportion of TNBC patients harbor either germline or somatic mutations in BRCA1, or epigenetic silencing of BRCA1, which renders them deficient in DNA repair. Virtually all BRCA1 deficient breast cancers harbor mutations in TP53 suggesting that inactivation of p53 is a requirement for tumor progression in the setting of BRCA1 deficiency. Due to this dependency, we hypothesized that restoring wild type p53 function in BRCA1 deficient breast cancer would be therapeutic. The majority of TP53 mutations are missense, which generate a defective protein that potentially can be targeted with small molecules. Zinc metallochaperones (ZMCs) are a new class of anti-cancer drugs that specifically reactivate zinc-deficient mutant p53 by restoring zinc binding. Using ZMC1 in human breast cancer cell lines expressing the zinc deficient p53R175H, we demonstrate that loss of BRCA1 sensitizes cells to mutant p53 reactivation. Using murine breast cancer models with Brca1 deficiency, we demonstrate that ZMC1 significantly improves survival of mice bearing tumors harboring the zinc-deficient Trp53R172H allele but not the Trp53−/− allele. We synthesized a new formulation of ZMC1 (Zn-1), in which the drug is made in complex with zinc to improve zinc delivery, and demonstrate that Zn-1 has increased efficacy. Furthermore, we show that ZMC1 plus olaparib is a highly effective combination for p53R172H tumor growth inhibition. In conclusion, we have validated preclinically a new therapeutic approach for BRCA1 deficient breast cancer through reactivation of mutant p53.

Details

Title
Therapeutic targeting of BRCA1 and TP53 mutant breast cancer through mutant p53 reactivation
Author
Na Bing 1 ; Yu, Xin 1 ; Withers, Tracy 2 ; Gilleran, John 3 ; Yao, Ming 2 ; Foo, Tzeh Keong 4 ; Chen, Chunxia 5 ; Moore, Dirk 5 ; Lin, Yong 5 ; David, Kimball S 6 ; Xia Bing 4 ; Ganesan Shridar 7 ; Carpizo Darren R 8 

 Rutgers Robert Wood Johnson Medical School, Department of Surgery, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers University Biomedical Research Cores, Rutgers University, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Department of Medicinal Chemistry, Rutgers Ernest Mario School of Pharmacy, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers Robert Wood Johnson Medical School, Department of Radiation Oncology, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Department of Biostatistics, Rutgers School of Public Health, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University Biomedical Research Cores, Rutgers University, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Department of Medicinal Chemistry, Rutgers Ernest Mario School of Pharmacy, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Office of Innovation & Research Commercialization, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Department of Pharmacology, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers Robert Wood Johnson Medical School, Department of Medicine, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796) 
 Rutgers Robert Wood Johnson Medical School, Department of Surgery, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers Cancer Institute of New Jersey, New Brunswick, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Rutgers University, Department of Pharmacology, Piscataway, USA (GRID:grid.430387.b) (ISNI:0000 0004 1936 8796); Z53 Therapeutics, Inc., Holmdel, USA (GRID:grid.430387.b) 
Publication year
2019
Publication date
2019
Publisher
Nature Publishing Group
e-ISSN
23744677
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2210005669
Copyright
© The Author(s) 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.