Abstract: Objective To investigate the effects of astragalus polysaccharide (APS) on proliferation, apoptosis, migration and invasion of multiple myeloma (MM) cell line U266 and potential mechanisms. Methods U266 cells were incubated with APS at different concentrations (6, 8 and 10 mg/mL) for 24, 48 and 72 h, or 8 mg/mL treated APS on U266 cells transfected with tumor necrosis factor receptor-associated factor 6 (TRAF6) expression plasmid (pcDNA3.1-TRAF6) for 48 h.The proliferation of U266 cells was detected by CCK-8 method. Apoptosis of U266 cells was detected by flow cytometry. Migration and invasion of U266 cells were detected by Transwell. The level of cyclin D1, p21, Bax, Bcl-2, E-cadherin, MMP-2 and TRAF6 protein expression was detected by Western blot. Results Compared with the control, the inhibition rate, apoptosis rate, migration and invasion number of U266 cells in APS group were significantly increased(P＜0.05), and the expression of cyclin D1, Bcl-2, MMP-2 and TRAF6 was significantly decreased(P＜0.05), and the expression of p21, Bax and E-cadherin was significantly elevated(P＜0.05). Compared with the APS+pcDNA3.1 group, the inhibition rate, apoptosis rate, migration and invasion number of U266 cells in APS+pcDNA3.1-TRAF6 group were significantly decreased(P＜0.05), and the expression of cyclin D1, Bcl-2, MMP-2 and TRAF6 was significant elevated(P＜0.05). The expression of p21, Bax and E-cadherin was significantly inhibited(P＜0.05). Conclusions APS may inhibit the proliferation, migration and invasion of U266 cells through down-regulating the expression of TRAF6 protein, and promote the apoptosis of U266 cells.

Key words: multiple myeloma, astragalus polysaccharides, TRAF6, apoptosis, migration