Galangin inhibits epithelial-mesenchymal transition and angiogenesis by downregulating CD44 in glioma.

Galangin (3,5,7­trihydroxyflavone), a natural flavonoid present in plants, has been reported to possess anticancer properties in various types of cancers comprising glioma. The underlying mechanism, however, has not been fully elucidated. CD44, a hall marker in glioma, has been reported to be associated with epithelial-mesenchymal transition (EMT) and angiogenesis, which play important roles in glioma progression. In this study, we aimed to investigate whether galangin can inhibit EMT, angiogenesis and CD44 expression in glioma. We observed that galangin inhibited the proliferation, migration, invasion and angiogenesis of glioma cells in a dose-dependent manner, suppressed the expression of CD44 and inhibited angiogenesis of glioma cells through downregulating vascular endothelial growth factor (VEGF) in HUVECs. In addition, the overexpression of CD44 in U87 and U251 cells partly abolished the effects of galangin on glioma cells. Moreover, galangin suppressed tumor growth in an intracranial glioma mouse model. These results indicate that galangin is a potential novel drug for glioblastoma treatment due to its ability to suppress of CD44, EMT and angiogenesis.

Identification of a small-molecule compound that inhibits homodimerization of oncogenic NAC1 protein and sensitizes cancer cells to anticancer agents.

Nucleus accumbens-associated protein-1 (NAC1) is a transcriptional repressor encoded by the NACC1 gene, which is amplified and overexpressed in various human cancers and plays critical roles in tumor development, progression, and drug resistance. NAC1 has therefore been explored as a potential therapeutic target for managing malignant tumors. However, effective approaches for effective targeting of this nuclear protein remain elusive. In this study, we identified a core unit consisting of Met7 and Leu90 in NAC1's N-terminal domain (amino acids 1-130), which is critical for its homodimerization and stability. Furthermore, using a combination of computational analysis of the NAC1 dimerization interface and high-throughput screening (HTS) for small molecules that inhibit NAC1 homodimerization, we identified a compound (NIC3) that selectively binds to the conserved Leu-90 of NAC1 and prevents its homodimerization, leading to proteasomal NAC1 degradation. Moreover, we demonstrate that NIC3-mediated down-regulation of NAC1 protein sensitizes drug-resistant tumor cells to conventional chemotherapy and enhances the antimetastatic effect of the antiangiogenic agent bevacizumab both in vitro and in vivo These results suggest that small-molecule inhibitors of NAC1 homodimerization may effectively sensitize cancer cells to some anticancer agents and that NAC1 homodimerization could be further explored as a potential therapeutic target in the development of antineoplastic agents.