δ-tocotrienol Inhibits Proliferation of Cervical Carcinoma Cells Through Upregulating MicroRNA-34a

Objective To determine the effects of δ-tocotrienol on the proliferation of cervical carcinoma HeLa cells and whether miR-34a is involved in this process. Methods The expression of miR-34a and proliferation-related genes, cell viability, the protein levels of proliferation-related genes and cell cycle were examined using Real-time PCR, CCK-8 assay, Western blot and flow cytometry, respectively. miR-34a mimics and inhibitors were used to determine whether miR-34a mediated the effects of δ-tocotrienol on cell proliferation. Results δ-tocotrienol treatment for 36h significantly decreased the viability of HeLa cells in a dose-dependent manner. δ-tocotrienol treatment at 20 μmol/L-1 for 36h significantly stimulated miR-34a expression, however, inhibited CCND1 expression; meanwhile, cells proportion in S phase was decreased. Besides, after miR-34a mimics transfection, the cell viability and CCND1 expression were also decreased. Furthermore, miR-34a inhibitor transfection attenuated the inhibitory effects of δ-tocot