Lexibulin dihydrochloride

Lexibulin (CYT-997) prevents the in vitro polymerization of tubulin with an IC50 of ～3 μmol/L (compared with the half-maximal inhibitory concentration of 2 μmol/L for colchicine under identical conditions) as determined using the conventional turbidimetric assay for tubulin polymerization. Lexibulin is also capable of reversibly disrupting the microtubule network in cells, visualized using fluorescence microscopy. Thus, treatment of A549 cells with Lexibulin (1 μM) lead to the rapid reorganization of microtubules, including the destruction of the existing microtubule network and accumulation of tubulin in plaques within the cytoplasm of some cells. After 24 hours, major alterations in cell morphology are evident, including loss of adhesion and cell rounding. The effect of 1 hour of treatment with Lexibulin is reversible and cells rapidly recovered their normal microtubule architecture. Taken together, the data indicates that Lexibulin belongs to the class of anticancer agents that disrupt, rather than stabilize, tubulin-containing structures. Although vehicle-treated cells show 15% and 19% in G2-M phase at 15 and 24 hours (respectively), cells treated with Lexibulin (1 μM) had 38% and 43% of cells in G2-M at the same time points. Furthermore, at 24 hours post-Lexibulin treatment, only 66% of total cells are in the G1, S, and G2-M phases, which suggests that cells blocked at the G2-M boundary do not exit back to G1, as in the normal cell cycle, but most likely are driven towards apoptosis and cell death^[1]. Consistent with the disruption of cellular tubulin, Lexibulin potently inhibits proliferation, induces cell cycle arrest and most importantly apoptosis of both human myeloma cell lines (HMCLs) and primary MM cells^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.