Breast cancer (BC) has a complex and heterogeneous etiology, and the emergence of resistance to conventional chemo-and radiotherapy results in unsatisfactory outcomes during BC treatment. Targeted nanomedicines have tremendous therapeutic potential in BC treatment over their free drug counterparts. Hence, this study aimed to evaluate the newly fabricated pH-sensitive multifunctional FAHA- Amygdalin@Fe2O3 nano-core-shell composite (AF nanocomposite) and/or γ-radiation for effective localized BC therapy. The physicochemical properties of nanoparticles were examined, including stability, selectivity, responsive release to pH, cellular uptake, and anticancer efficacy. MCF-7 and MDA-MB-231 cells were treated with AF at the determined IC50 doses and/or exposed to γ-irradiation (RT) or were kept untreated as controls. The antitumor efficacy of AF was proposed via assessing anti-proliferative effects, cell cycle distribution, apoptosis, and determination of the oncogenic effectors. In a bio-relevant medium, AF nanoparticles demonstrated extended-release characteristics that were amenable to acidic pH and showed apparent selectivity towards BC cells. The bioassays revealed that the HA and FA-functionalized AF markedly hindered cancer cell growth and enhanced radiotherapy (RT) through inducing cell cycle arrest (pre-G1 and G2/M) and increasing apoptosis, as well as reducing the tumorigenicity of BCs by inhibiting Silent information regulation factor 1 (SIRT1) and restoring p53 expression, deactivating the Yes-associated protein (YAP)/ Transcriptional coactivator with PDZ-binding motif (TAZ) signaling axis, and interfering with the tumor growth factor- β(TGF- β)/SMAD3 and HIF-1α/VEGF signaling hub while up-regulating SMAD7 protein expression. Collectively, the novel AF alone or prior RT abrogated BC tumorigenicity.
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