MicroRNA‐214‐3p modified tetrahedral framework nucleic acids target survivin to induce tumour cell apoptosis

OBJECTIVES: Due to the instability of microRNAs, the applications of microRNA are currently limited. Thus, we utilized tetrahedral framework nucleic acids and a targeted microRNAs to form a stable nanocomposite to explore whether this nanocomposite can promote apoptosis of tumour cells. MATERIALS AND METHODS: In our study, the survivin gene, which is expressed only in tumour cells and embryonic cells, was selected as the target gene; miRNA-214-3p, which can reduce the expression of survivin, was modified onto tetrahedral framework nucleic acid, thereby producing a reduction in the expression of survivin upon intracellular delivery and eventually leading to tumour cell apoptosis. RESULTS: By comparing the stability of microRNAs with that of microRNA-tetrahedral framework nucleic acid, we proved the superiority of this carrier system. The results of flow cytometry showed that after treated with this complex, the ratio of A549 cells in both late and early period of apoptosis in miRNA-214-3p-tetrahedral framework nucleic acid group had doubled and the cell cycle in the G2-M phase had declined. The decrease in the expression of anti-apoptotic protein and the increase in the expression of pro-apoptotic protein indicate that the ability of this complex to function in cells also makes it attractive as a new targeted therapy for cancer. CONCLUSION: The unique expression of survivin in tumour cells and embryonic cells makes microRNA-tetrahedral framework nucleic acid a new targeted therapy. In addition, due to the functional diversity of microRNAs, this delivery system approach can be applied to a wide variety of fields, such as targeted therapy and tissue regeneration.