Paclitaxel nanocrystals carrying miR-200c inhibit prostate cancer in rats by regulating forkhead box protein O (FOXO) activity

Abstract

Prostate cancer is a malignant tumor in the male reproductive organs. Its incidence is increasing year by year, and therefore, this study investigated regulatory effect of paclitaxel nanocrystals on forkhead box protein O (FOXO) activity in rats with prostate cancer. Firstly, paclitaxel nanocrystals carrying miRNA-200c were synthesized. Nine rats in the model control group were used to establish a tumor-bearing model. The rats were intervened with miRNA-200c in the miRNA-200c group on the basis of model group, and treated with paclitaxel nanosuspension in the paclitaxel nano group. The rats were intervened with paclitaxel nano and miRNA-200c in the paclitaxel nano+miRNA-200c group. Tumor inhibition rates were measured, and tumor cell morphology was assessed by hematoxylin-eosin (HE) staining, while cell behaviors were detected by CCK-8, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT), AnnexinV-Fluorescein isothiocyanate (FITC), and Transwell methods, which were used to analyze miRNA-200c and FOXO levels. Paclitaxel nanocrystals carrying miR-200c (PN-miR-200c) significantly slowed down the growth rate of prostate cancer. In addition, it also reduced the viability, proliferation and invasion of rat PC3 cells, and increased cell apoptosis. On the other hand, PN-miR-200c further increased FoxO mRNA expression by activating FoxO pathway. The bioinformatics software RegRNA 2.0 predicted that, the specific target gene that may be regulated by miR-200c is FoxO, which confirmed that, the miR-200c has a targeting relationship with FoxO. PN-miR-200c can activate FOXO pathway, up-regulate FoxO, reduce the biological behaviors of rat PC3 cells, increase apoptosis, and ameliorate histopathological damage, providing new ideas for clinical treatment of prostate cancer.