Small molecule nitroalkenes inhibit RAD51-mediated homologous recombination and amplify triple-negative breast cancer cell killing by DNA-directed therapies
Lisa Hong,
Dennis C. Braden,
Yaoning Zhao,
John J. Skoko,
Fei Chang,
Steven R. Woodcock,
Crystall Uvalle,
Allison Casey,
Katherine Wood,
Sonia R. Salvatore,
Alparslan Asan,
Trey Harkness,
Adeola Fagunloye,
Mortezaali Razzaghi,
Adam Straub,
Maria Spies,
Daniel D. Brown,
Adrian V. Lee,
Francisco Schopfer,
Bruce A. Freeman,
Carola A. Neumann
Affiliations
Lisa Hong
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Dennis C. Braden
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Yaoning Zhao
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA; School of Medicine, Tsinghua University, Beijing, China
John J. Skoko
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Fei Chang
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Steven R. Woodcock
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Crystall Uvalle
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Allison Casey
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Katherine Wood
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Sonia R. Salvatore
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Alparslan Asan
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Trey Harkness
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Adeola Fagunloye
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA
Mortezaali Razzaghi
Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
Adam Straub
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Maria Spies
Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
Daniel D. Brown
Institute for Precision Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Adrian V. Lee
Institute for Precision Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Francisco Schopfer
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Bruce A. Freeman
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
Carola A. Neumann
Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Women's Cancer Research Center, UPMC Hillman Cancer Center, Magee-Women's Research Institute, Pittsburgh, PA, USA; Corresponding author. Department of Pharmacology and Chemical Biology University of Pittsburgh 5051 Centre Ave, Pittsburgh, 15213, PA, USA.
Nitro fatty acids (NO2-FAs) are endogenously generated lipid signaling mediators from metabolic and inflammatory reactions between conjugated diene fatty acids and nitric oxide or nitrite-derived reactive species. NO2-FAs undergo reversible Michael addition with hyperreactive protein cysteine thiolates to induce posttranslational protein modifications that can impact protein function. Herein, we report a novel mechanism of action of natural and non-natural nitroalkenes structurally similar to (E) 10-nitro-octadec-9-enoic acid (CP-6), recently de-risked by preclinical Investigational New Drug-enabling studies and Phase 1 and Phase 2 clinical trials and found to induce DNA damage in a TNBC xenograft by inhibiting homologous-recombination (HR)-mediated repair of DNA double-strand breaks (DSB). CP-6 specifically targets Cys319, essential in RAD51-controlled HR-mediated DNA DSB repair in cells. A nitroalkene library screen identified two structurally different nitroalkenes, a non-natural fatty acid [(E) 8-nitro-nonadec-7-enoic acid (CP-8)] and a dicarboxylate ester [dimethyl (E)nitro-oct-4-enedioate (CP-23)] superior to CP-6 in TNBC cells killing, synergism with three different inhibitors of the poly ADP-ribose polymerase (PARP) and γ-IR. CP-8 and CP-23 effectively inhibited γ-IR-induced RAD51 foci formation and HR in a GFP-reported assay but did not affect benign human epithelial cells or cell cycle phases. In vivo, CP-8 and CP-23's efficacies diverged as only CP-8 showed promising anticancer activities alone and combined with the PARP inhibitor talazoparib in an HR-proficient TNBC mouse model. As preliminary preclinical toxicology analysis also suggests CP-8 as safe, our data endorse CP-8 as a novel anticancer molecule for treating cancers sensitive to homologous recombination-mediated DNA repair inhibitors.
