Superparamagnetic Iron Oxide Nanoparticles Directed miRNA-34b-RNA-Binding Proteins T Cell to Restrict Intracellular Antigen-1-Stress Granules (TIA-1-SG) in Breast Cancer Chemotherapy

miRNA-34b-T cell restricted intracellular antigen-1-stress granules (miRNA-34b-TIA-1-SG) superparamagnetic iron oxide nanoparticles were studied in this project and their directional function will provide a new carrier for improving directional improvement of interventional therapeutic drugs for breast cancer. We explored its therapeutic effect on breast cancer treatment through the following groups; Group I: blank control group (injected with 0.9% normal saline 0.5 mL to the tail vein), Group II: miRNA-34b-TIA-1-SG group (superparamagnetic iron oxide miRNA-34b-TIA-1-SG nanoparticles given by tail vein injection), Group III: superparamagnetic iron oxide-oriented miRNA-34b-TIA-1-SG group (superparamagnetic iron oxide nanoparticles given by tail vein injection). In vitro experiment involved the following methods: MTT, flow cytometry and colony formation experiment, all used to evaluate biological processes of tumor cells after tail vein injection of superparamagnetic iron oxide directed miRNA-34b-TIA-1-SG. In vivo experiments involved the following: tumor xenotransplantation experiment, used to observe the effect of tail vein injection of superparamagnetic iron oxide-oriented miRNA-34b-TIA-1-SG on the treatment effect of breast cancer. Both In vivo experiments and In vitro experiments in MDA-MB-231 cells confirmed that superparamagnetic iron oxide-oriented miRNA-34b-TIA-1-SG nanoparticles effectively inhibited breast cancer cells proliferation and colony formation, and also promoted cell apoptosis. Promotion of cell apoptosis is one of the main ways to treat breast cancer, as appearance of stress granules inhibits cell apoptosis, so regulating stress granules to promote the apoptosis of breast cancer cells is an important treatment strategy. TIA-1 is an essential component of stress granules, and miRNA-34b was significantly down-regulated in breast cancer cells. Therefore, the hypothesis that miRNA-34b-TIA-1-SG signal axis regulates cell apoptosis and promotes breast cancer cell proliferation is herein proposed. We constructed the miRNA-34b reporter gene system, and our study showed that the superparamagnetic iron oxide oriented miRNA-34b-TIA-1-SG nanoparticles may be used as a development direction for breast cancer treatment, which may provide a new and highly effective molecular-oriented drug.