Fig. 1.

Marizomib inhibits the proteasome activity, proliferation, and invasion of glioma cells. (A) Proteasome activity was measured in glioma cell lines D-54 and U-251 after treatment with marizomib (60 nM). The chymotrypsin-like activity of treated cells was presented as a percentage of untreated cells. (B) Marizomib treatment for 72 hours effectively reduced survival of D-54 and U-251 cells in a dose-dependent manner. The IC50s were shown in a lower panel. (C) Proteasome activity was measured in neural stem cells and glioblastoma-derived glioma stem cells at baseline and 2 hours after treatment with marizomib (60 nM). (D) Marizomib showed different proliferation inhibition on diverse primary cell cultures after treatment for 72 hours. (E) Invasion capability of cells treated or untreated with 60 nM marizomib for 24 hours was analyzed using Matrigel invasion chambers. The average of invaded cells for each counting grid was shown in the lower panel. ***P < .001.