Quercetin enhances radiosensitivity in T۴۷D breast cancer cells: impact on DNA damage, clonogenic survival, and antioxidant defenses

Introduction: Radiotherapy resistance remains a significant challenge in breast cancer treatment. Quercetin, a natural flavonoid, has emerged as a potential radiosensitizer. This study examined its effects on hormone receptor-positive T۴۷D breast cancer cells.Materials and methods: T۴۷D cells were treated with quercetin (۲۰, ۴۰, ۶۰ μM) alone or combined with ionizing radiation (۲, ۳ Gy). DNA damage (micronucleus assay), clonogenic survival, and antioxidant enzyme activities (SOD, catalase) were evaluated.Results: Radiation alone significantly increased micronucleus formation (۴.۳-۹.۵ fold vs control, p<۰.۰۰۰۱) and reduced clonogenic survival (۴۴-۶۲% reduction vs control, p<۰.۰۰۰۱), while decreasing SOD (۱۶-۲۴.۵%) and catalase (۱۸-۲۲%) activities (p<۰.۰۰۰۱). Quercetin pretreatment enhanced these effects in a dose-dependent manner. The combination of ۶۰ μM quercetin with ۳ Gy radiation resulted in: a ۱۰% greater micronucleus formation than radiation alone (p<۰.۰۱), further reduction in clonogenic survival to ۱۷% of control values (۸۳% reduction vs radiation alone, p<۰.۰۰۱), and up to ۴۸% greater suppression of antioxidant enzyme activity compared to radiation-only groups (p < ۰.۰۱).Conclusion: Quercetin demonstrates significant radiosensitizing effects in T۴۷D cells through the enhancement of DNA damage and oxidative stress. The substantial reduction in clonogenic survival suggests potential clinical relevance, warranting further investigation in advanced models.Introduction: Radiotherapy resistance remains a significant challenge in breast cancer treatment. Quercetin, a natural flavonoid, has emerged as a potential radiosensitizer. This study examined its effects on hormone receptor-positive T۴۷D breast cancer cells. Materials and methods: T۴۷D cells were treated with quercetin (۲۰, ۴۰, ۶۰ μM) alone or combined with ionizing radiation (۲, ۳ Gy). DNA damage (micronucleus assay), clonogenic survival, and antioxidant enzyme activities (SOD, catalase) were evaluated. Results: Radiation alone significantly increased micronucleus formation (۴.۳-۹.۵ fold vs control, p<۰.۰۰۰۱) and reduced clonogenic survival (۴۴-۶۲% reduction vs control, p<۰.۰۰۰۱), while decreasing SOD (۱۶-۲۴.۵%) and catalase (۱۸-۲۲%) activities (p<۰.۰۰۰۱). Quercetin pretreatment enhanced these effects in a dose-dependent manner. The combination of ۶۰ μM quercetin with ۳ Gy radiation resulted in: a ۱۰% greater micronucleus formation than radiation alone (p<۰.۰۱), further reduction in clonogenic survival to ۱۷% of control values (۸۳% reduction vs radiation alone, p<۰.۰۰۱), and up to ۴۸% greater suppression of antioxidant enzyme activity compared to radiation-only groups (p < ۰.۰۱). Conclusion: Quercetin demonstrates significant radiosensitizing effects in T۴۷D cells through the enhancement of DNA damage and oxidative stress. The substantial reduction in clonogenic survival suggests potential clinical relevance, warranting further investigation in advanced models.

کلیدواژه ها:

Radiosensitizer ، Breast cancer ، Micronucleus ، Oxidative stress ، Radiotherapy