The proto-oncogene c-Myb plays an important role in cell proliferation, and its upregulation affects the development of
glioblastomas. G-quadruplexes are secondary
DNA or
RNA structures that usually form in the promoter region of oncogenes, including c-Myb, and regulate the expression of these genes. The
traditional Chinese medicine,
brucine, is a
ligand of the G-quadruplexes located in the promoter region of c-Myb. The present study investigated the
therapeutic effects and mechanism of action of
brucine in U87, LN18, and LN229 cells in vitro and in vivo. Our results showed that
brucine suppressed the growth of these cells in vitro by arresting the cell cycle and reducing c-Myb expression. Dual-
luciferase reporter assays showed that
brucine inhibited c-Myb expression by targeting the
guanine-rich sequence that forms G-quadruplexes in the c-Myb promoter. Moreover, U87
tumors were suppressed by
brucine in a
tumor xenograft nude mouse model. Therefore,
brucine is potentially effective for treating
glioblastomas.