Berberine Suppressed the Progression of Human Glioma Cells by Inhibiting the TGF-β1/SMAD2/3 Signaling Pathway

Abstract

Background: Previous studies have shown that berberine can inhibit glioma progression, although the underlying molecular mechanisms needed to be explored further. The aim of this study was to evaluate the suppressive effects of berberine on human glioma cells, and identify the underlying signaling pathways. Material and Methods: The cytotoxic effect of different concentrations of berberine against normal human glial cells (HEB) and 4 glioma cell lines was evaluated by the CCK-8 assay. Apoptosis was assayed by flow cytometry. In vitro migration and invasion were analyzed by the wound healing and transwell assays. The expression levels of specific proteins were measured by western blotting and ELISA. Results: Berberine significantly inhibited the proliferation of human glioma U-87 cells, and induced apoptosis in the U-87 and LN229 cells by downregulating Bcl-2, and upregulating Bax and caspase-3. In addition, berberine also inhibited migration and invasion of the glioma cells. Furthermore, berberine exerted its effects on the proliferation, migration, invasion, and apoptosis of glioma cells by inhibiting the TGF-β1/SMAD2/3 signaling pathway, and exogenous TGF-β abrogated the pro-apoptotic and anti-oncogenic effects of berberine. Conclusions: Berberine inhibits glioma progression by targeting the TGF-β1/SMAD2/3 signaling pathway.