[Preliminary study on the effect of TRAIL on adhesion and apoptosis of multiple myeloma cell line RPMI8226 and its mechanism]

The present study was purposed to investigate the inhibition effect of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on growth of RPMI8226 cells and adhesion between RPMI8226 cells and bone marrow stroma cells (BMSC), and to explore its mechanism as well. The inhibition effects of TRAIL on cells growth and adhesion were assayed by MTT; cell apoptosis was detected by Annexin V and PI; expression of genes bax, bcl-2, mcl-1, CARP1, CARP2, XIAP and cFLIP were determined by semi-quantitative RT-PCR; apoptosis-related protein expression was detected by Western blot. The results showed that TRAIL inhibited the proliferation of RPMI8226 cells in dose- and time-dependent manners. TRAIL induced apoptosis in RPMI8226 cells, the expression level of genes bcl-2, mcl-1, CARP1, CARP2, XIAP and cFLIP decreased, while the expression level of Bax increased, but the expression level of caspase-3 and NF-kappaB P65(RelA) proteins decreased. Moreover, TRAIL up-regulated the expression level of adherent molecule CXCR4 in RPMI8226 cells significantly. It is concluded that TRAIL up-regulated the expression level of adherent molecule CXCR4 in RPMI8226 cells significantly, and induced the apoptosis of RPMI8226 cells. Growth inhibition effect of TRAIL on RPMI8226 cells is in dose- and time-dependent manners.