Electrophilic fatty acids impair RAD51 function and potentiate the effects of DNA-damaging agents on growth of triple-negative breast cells
| Autor: | Bentley M. Wingert, Chen-Shan Chen Woodcock, Yi Huang, Jeremy M. Stark, Daniel P. Normolle, Carlos J. Camacho, Alparslan Asan, Carola A. Neumann, Bruce A. Freeman, John J. Skoko, Steven R. Woodcock |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Alkylation DNA Repair DNA repair genetic processes RAD51 Antineoplastic Agents Triple Negative Breast Neoplasms Proto-Oncogene Mas Biochemistry 03 medical and health sciences chemistry.chemical_compound PARP1 medicine Humans Proto-Oncogene Proteins c-abl Molecular Biology Cell Proliferation Cisplatin 030102 biochemistry & molecular biology Chemistry Fatty Acids Cell Biology Molecular biology Non-homologous end joining enzymes and coenzymes (carbohydrates) 030104 developmental biology Doxorubicin Accelerated Communications Phosphorylation Drug Therapy Combination Rad51 Recombinase biological phenomena cell phenomena and immunity Homologous recombination DNA DNA Damage Protein Binding medicine.drug |
| Zdroj: | Journal of Biological Chemistry. 294:397-404 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.ac118.005899 |
| Popis: | Homologous recombination (HR)-directed DNA double-strand break (DSB) repair enables template-directed DNA repair to maintain genomic stability. RAD51 recombinase (RAD51) is a critical component of HR and facilitates DNA strand exchange in DSB repair. We report here that treating triple-negative breast cancer (TNBC) cells with the fatty acid nitroalkene 10-nitro-octadec-9-enoic acid (OA-NO(2)) in combination with the antineoplastic DNA-damaging agents doxorubicin, cisplatin, olaparib, and γ-irradiation (IR) enhances the antiproliferative effects of these agents. OA-NO(2) inhibited IR-induced RAD51 foci formation and enhanced H2A histone family member X (H2AX) phosphorylation in TNBC cells. Analyses of fluorescent DSB reporter activity with both static-flow cytometry and kinetic live-cell studies enabling temporal resolution of recombination revealed that OA-NO(2) inhibits HR and not nonhomologous end joining (NHEJ). OA-NO(2) alkylated Cys-319 in RAD51, and this alkylation depended on the Michael acceptor properties of OA-NO(2) because nonnitrated and saturated nonelectrophilic analogs of OA-NO(2), octadecanoic acid and 10-nitro-octadecanoic acid, did not react with Cys-319. Of note, OA-NO(2) alkylation of RAD51 inhibited its binding to ssDNA. RAD51 Cys-319 resides within the SH3-binding site of ABL proto-oncogene 1, nonreceptor tyrosine kinase (ABL1), so we investigated the effect of OA-NO(2)–mediated Cys-319 alkylation on ABL1 binding and found that OA-NO(2) inhibits RAD51–ABL1 complex formation both in vitro and in cell-based immunoprecipitation assays. The inhibition of the RAD51–ABL1 complex also suppressed downstream RAD51 Tyr-315 phosphorylation. In conclusion, RAD51 Cys-319 is a functionally significant site for adduction of soft electrophiles such as OA-NO(2) and suggests further investigation of lipid electrophile–based combinational therapies for TNBC. |
| Databáze: | OpenAIRE |
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