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.

Background. Hemangioblastoma occurs mainly in the cerebellum and rarely in the cerebrum. Objective. The present study aimed to analyze the clinical manifestations and radiological and pathological features of cerebral hemangioblastoma, and to improve the recognition of this tumor and avoid misdiagnosis. Methods. The characteristics of 6 patients with cerebral hemangioblastoma were analyzed, and a retrospective review of cerebral hemangioblastoma reported in the literature was performed. Results. All 6 patients were female, aged from 22 to 70 years (55 years on average), and all cases were wild-type sporadic, in which 4 cases occurred in the frontal lobe and 2 cases occurred in the parietal lobe. Imaging revealed a solid tumor in 4 cases, a cystic tumor in 1 case, and a mixed tumor in 1 case. Microscopically, the morphology and immunophenotype of tumor cells were not different from those of classical hemangioblastoma. All 6 patients survived tumor free during the follow-up period. Conclusions. Cerebral hemangioblastoma often simulates the imaging characteristics of meningioma or glioma. Enough attention should be paid to differential diagnosis before the operation, and exact diagnosis relies on the pathological examination.

Background: The proto-oncogene c-Myb plays an important role in the proliferation of cells and its upregulation affects the development of glioblastomas. G-quadruplexes are secondary structures of DNA or RNA 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 G-quadruplexes located in the promoter region of c-Myb. In this study, the U87 cell line was used both in vitro and in vivo to investigate the therapeutic effect and mechanism of action of brucine. Methods: MTT assay and flow cytometry were used to determine the effect of brucine on the cell cycle, viability, and apoptosis of U87 cells. The effects of brucine on transcription and expression of c-Myb were determined through RT-PCR and western blotting. Dual-luciferase reporter assay and electrospray ionization-mass spectrometry were used to investigate whether brucine acts directly and binds G-quadruplexes in the promoter region of c-Myb, respectively. Results: The results showed that brucine suppressed the growth of U87 cells in vitro by arresting the cell cycle and reducing the expression of c-Myb. Through the dual luciferase reporter assay, brucine was found to inhibit the expression of c-Myb 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 mice model. Conclusion: The findings of the study indicate that brucine is a potentially effective medicine for treatment of glioblastomas.