Akademik Veri Yönetim Sistemi
7. Uluslararası ve 36. Ulusal Biyofizik Kongresi / 7th International and 36th National Biophysics Congress, Bursa, Türkiye, 3 - 06 Eylül 2025, ss.113, (Özet Bildiri)
Aim: Triple-negative breast cancer (TNBC) represents a distinct subtype among breast cancers, characterized by poor clinical outcomes due to its aggressive nature and limited therapeutic targets. TP53 mutations are observed in approximately 75% of TNBC cases. Simultaneous overexpression of murine double minute 2 (MDM2) and murine double minute 4 (MDM4) further weakens p53-mediated tumor suppression, contributing to therapeutic resistance and reduced patient survival. This study aimed to overcome apoptotic resistance in TNBC through the combination of the dual MDM2/MDM4 inhibitor RO5963 and cold atmospheric plasma (CAP), which generates high-frequency electromagnetic waves. Materials and Methods: Murine 4T1 TNBC cell line was used in this study. Cells were treated for 24 hours with RO5963 at its IC₅₀ concentration (23.3 μM), as determined by prior WST-1 cytotoxicity assays, and/or CAP exposure administered twice for 30 seconds each. Following treatment, cell death mechanisms were evaluated via dual staining with Annexin V-FITC and propidium iodide (PI), and analyzed using flow cytometry. Results: Individual treatments induced significant apoptosis compared to untreated controls: RO5963 monotherapy elevated cell death from 4.42±0.05% to 11.20±0.1% (p<0.001), while CAP treatment achieved 12.71±0.07% apoptosis (p<0.001). The combination regimen demonstrated enhanced cytotoxic efficacy, attaining 19.13±0.1% apoptosis, representing a 4.3-fold increase relative to controls (p<0.001) and 71% greater efficacy compared to RO5963 monotherapy. Mechanistic analysis revealed distinct cell death pathway preferences: RO5963 predominantly induced necroptosis (11.10±0.08%), whereas CAP preferentially activated apoptotic mechanisms. The combination treatment engaged both pathways concurrently, suggesting complementary modes of action. Conclusion: These findings demonstrate that RO5963 and CAP exhibit synergistic anticancer activity in TNBC cells via distinct yet complementary cell death mechanisms. This combination strategy offers a novel mechanistic approach to overcoming apoptotic resistance in TNBC. Keywords: Triple-negative breast cancer, MDM2/MDM4 inhibitor, cold atmospheric plasma, synergistic therapy, apoptotic resistance