OBJECTIVETo investigate if NS-398 could enhance the chemosensitivity of Bortezomib (BOR) on human multiple myeloma RPMI 8226 cells.

METHODSAfter the treatment of NS-398 combined with BOR, MTT assay was used to detect the proliferation inhibition effect on human multiply myeloma RPMI 8226 cells in vitro, Flow cytometry was used to analyze their effect of apoptosis and cell cycle; the caspase-3 activity of different treatment group was detected by using ELISA and the activity of Cox-2 was measured by using Cox-2 activity assay kit.

RESULTSThe inhibitory rate of NS-398 combined with BOR was higher than that of NS-398 or BOR alone(Q>0.85). After treatment of NS-398 combined with BOR, the percentage of cells arrested in the G/Gphase and apoptotic rate were both higher than that of treatment with each drug alone(Q>1.15). The caspase-3 activity in cells treated with combined of NS-398 and BOR was significantly higher than that of treatment of each drug alone(Q>1.15).

CONCLUSIONNS-398 combined with BOR shows a synergistic effect on the growth inhibition of RPMI 8226 cells in vitro.