Abstract
BACKGROUND: This study aimed to investigate the effects of miR-451 on proliferation, invasion, and migration of the papillary thyroid carcinoma (PTC) cell line TPC-1, focusing on its regulatory role in the PI3K/AKT/mTOR signaling pathway. METHODS: TPC-1 cells were transfected with siRNA-NC, miR-451 mimic, or miR-451 inhibitor and treated with the PI3K activator 740Y-P (miR-451 mimic + 740Y-P) where indicated. Cell proliferation, migration, and invasion were assessed using MTT, wound healing, and transwell assays, respectively. Protein expression and pathway activation were analyzed by western blot. RESULTS: Compared to the blank and siRNA-NC groups, the miR-451 mimic group showed significantly lower expression of Bcl-2, p-PI3K, p-AKT, and p-mTOR proteins, along with significantly higher expression of Bax (P < 0.05). Conversely, the miR-451 inhibitor group exhibited significantly elevated levels of Bcl-2, p-PI3K, p-AKT, and p-mTOR and significantly reduced Bax expression (P < 0.05). Furthermore, compared with the miR-451 mimic group, the miR-451 mimic + 740Y-P group displayed significantly increased expression of Bcl-2, p-PI3K, p-AKT, and p-mTOR, along with significantly decreased Bax levels (P < 0.05). CONCLUSIONS: miR-451 expression is significantly reduced in PTC tissues and TPC-1 cells. Overexpression of miR-451 inhibits proliferation, invasion, and migration in TPC-1 cells, likely via the PI3K/AKT/mTOR signaling pathway, suggesting its potential as a molecular target for further investigation in PTC.