Melatonin Inhibits the Malignant Progression of Glioblastoma via Regulating miR-16-5p/PIM1

Melatonin (MT) is a pineal hormone with antineoplastic potential. This study aims to explore the therapeutic potential and mechanism of MT on glioblastoma (GBM).A human GBM cell line, LN229, was used to evaluate the function of MT. Cell viability, apoptosis, and migration were detected by CCK-8, flow cytometry, and transwell assays, respectively. The mRNA and protein expressions of specific genes were measured by qRT-PCR and western blot, respectively. The regulatory relationship between miR-16-5p and PIM1 was validated by dual luciferase reporter gene assay. A mouse xenograft model was established to prove the anti-tumor effect and related mechanisms of MT in vivo.MT inhibited the viability and migration and promoted the apoptosis of LN229 cells in a dose-dependent manner. MiR-16-5p was dose-dependently up-regulated by MT in LN229 cells, negatively regulating its target PIM1. MiR-16-5p inhibitor eliminated the anti-tumor effect of MT in LN229 cells, while si-PIM1 reversed the effect of miR-16-5p inhibitor in MT-treated cells. MT inhibited the tumor growth in vivo and MT-induced PIM1 down-regulation was reversed by miR- 16-5p inhibition in tumor tissues.MT inhibits the malignant progression of GBM via regulating miR-16-5p-mediated PIM1.