Brassinin Inhibits Cell Survival and Autophagy via Modulation of ROS Production and the AMPKα-beclin1 Signaling Pathway in Gliomas.

Abstract

Brassinin, a phytoalexin compound derived mainly from Chinese cabbage, shows anticancer activity against several types of cancer. In this study, we aimed to investigate the role of brassinin in glioma progression and reveal the underlying mechanism. CCK8 assays were used to investigate the dose- and time-dependent effects of brassinin on the growth of different glioma cell lines, and then colony formation assays were employed to measure cell proliferation. Next, we used flow cytometry/Western blotting to assess cell cycle progression, apoptosis, and reactive oxygen species (ROS) production, and employed Western blotting/fluorescence staining for LC3, p62, and other signaling molecules to evaluate autophagy. Finally, we confirmed the in vitro findings in both the subcutaneous and intracranial glioma models using hematoxylin and eosin staining, immunohistochemistry, and immunofluorescence. Brassinin blocked cell cycle progression, inhibited proliferation, and promoted apoptosis in glioma cells. Brassinin inhibited autophagy, induced ROS overproduction, and suppressed the expression/activity of AMPKα-beclin1 signaling. The effect of brassinin on cell growth and survival was partially reversed by an ROS scavenger or an autophagy activator in glioma cells. Brassinin regulated the AMPKα/beclin1 signaling and autophagy via promoting ROS production in glioma cells. The anticancer role of brassinin was confirmed in subcutaneous and intracranial glioma models, and brassinin administration prolonged the survival of tumor-bearing mice. Brassinin inhibited cell survival and autophagy in glioma cells via modulation of ROS production and the AMPKα-beclin1 signaling pathway. Our study identified a promising botanical drug for the treatment of gliomas.