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Published on: March 20, 2018
Oleanolic Acid Modulates DNA Damage Response to Camptothecin Increasing Cancer Cell Death
Giulio Mazzarotti1, Maria Cuomo1, Maria Carmen Ragosta1
1Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy.
Abstract:
Targeting DNA damage response (DDR) pathways represents one of the principal approaches in cancer therapy. However, defects in DDR mechanisms, exhibited by various tumors, can also promote tumor progression and resistance to therapy, negatively impacting patient survival. Therefore, identifying new molecules from natural extracts could provide a powerful source of novel compounds for cancer treatment strategies. In this context, we investigated the role of oleanolic acid (OA), identified in fermented Aglianico red grape pomace, in modulating the DDR in response to camptothecin (CPT), an inhibitor of topoisomerase I. Specifically, we found that OA can influence the choice of DNA repair pathway upon CPT treatment, shifting the repair process from homologous recombination gene conversion to single-strand annealing. Moreover, our data demonstrate that combining sub-lethal concentrations of OA with CPT enhances the efficacy of topoisomerase I inhibition compared to CPT alone. Overall, these findings highlight a new role for OA in the DDR, leading to a more mutagenic DNA repair pathway and increased sensitivity in the HeLa cancer cell line.
Insights
Oleanolic acid from red grape pomace alters DNA repair pathways, increasing cancer cell sensitivity to camptothecin. This natural compound enhances topoisomerase I inhibition for improved cancer treatment strategies.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Targeting DNA damage response (DDR) pathways is crucial in cancer therapy.
- Tumor DDR defects can lead to progression and therapy resistance.
- Natural product extracts offer potential novel cancer treatment compounds.
Purpose of the Study:
- Investigate oleanolic acid's (OA) role in modulating DDR.
- Determine OA's effect on DNA repair pathway choice during camptothecin (CPT) treatment.
- Evaluate the combined efficacy of OA and CPT in cancer cells.
Main Methods:
- Utilized fermented Aglianico red grape pomace extract containing oleanolic acid.
- Treated HeLa cancer cells with OA and camptothecin (CPT).
- Assessed DNA repair pathway modulation and cell sensitivity.
Main Results:
- Oleanolic acid shifted DNA repair from homologous recombination to single-strand annealing upon CPT treatment.
- Combined sub-lethal OA and CPT enhanced topoisomerase I inhibition efficacy.
- OA promoted a more mutagenic DNA repair pathway, increasing HeLa cell sensitivity.
Conclusions:
- Oleanolic acid plays a novel role in modulating the DNA damage response.
- OA enhances cancer cell sensitivity to topoisomerase I inhibitors like CPT.
- OA represents a potential therapeutic agent for cancer treatment strategies.
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