microRNA-875-5p-conjugated gold nanoparticles suppress breast cancer progression through the MTDH/PTEN/AKT signaling pathway.

OBJECTIVE: A lack of effective delivery methods has hampered the study of therapeutics targeting miR-875-5p for breast cancer (BC). METHODS: The miR-875-5p mimic was conjugated to AuNPs to produce AuNP-miR-875-5p. Then, the effect of AuNP-miR-875-5p on the proliferative, migratory, invasive activities, and apoptosis of BC cells was detected, as well as on tumor growth in animals. The involvement of the MTDH/PTEN/AKT pathway in miR-875-5p-mediated BC progression was identified. RESULTS: AuNP-miR-875-5p was delivered to BC cells and hampered cell malignancy. MTDH was targeted by miR-875-5p. MTDH expression was negatively correlated with miR-875-5p expression in BC tissues. The anti-tumor effect of AuNP-miR-875-5p in BC cells was counteracted by MTDH overexpression. AuNP-miR-875-5p enhanced PTEN protein expression, thereby inhibiting AKT activation by targeting MTDH. AuNP-miR-875-5p blocked MCF-7 tumor growth in vivo. CONCLUSION: AuNPs can deliver miR-875-5p to BC cells, and AuNP-miR-875-5p has clinical potential for treating unresectable BC.