三氧化二砷诱导体外多发性骨髓瘤细胞凋亡

目的探讨三氧化二砷（ATO）体外对多发性骨髓瘤（MM）增殖凋亡、粘附分子、细胞因子的作用及机制。方法采用四甲基偶氮唑蓝（MTT）比色法检测ATO对骨髓瘤细胞株U266抑制作用，求出其IC50，膜联蛋白V（Annexin-V）检测凋亡并进行细胞周期分布分析，流式细胞术检测细胞间粘附分子的表达强度，RT—PCR检测CXCR4、c-Myc、Rb、Bax／bcl—XL（Bcl-2家族基因）、RANK—L、CyclinD1及血管内皮生长因子（VEGF）mRNA的表达。结果ATO在体外可抑制U266细胞的增殖，且呈现剂量和时间依赖性。ATO可使骨髓瘤细胞分裂阻滞于G0／G1期，并促进U266发生早期凋亡。经ATO作用后U266细胞高表达CD11a等粘附分子。U266细胞高表达CXCR4、bcl—XL和c-Myc基因，经ATO作用后其表达显著下调。U266处理前后均未检测到Rb、CyclinD1、VEGF、Bax，尤其是RANK—L基因的表达。结论ATO通过下调c-Myc和bcl—XL基因促进U266细细胞凋亡，并使G0／G1期细胞分裂阻滞，影响粘附分子表达，并可能通过CXCR4影响归巢。

Arsenic trioxide(ATO)induces multiple myeloma cell line U266 apoptosis in vitro

Objective To investigate the effect of arsenic trioxide(ATO) on myeloma cell line U266in vitro and its mechanism.Methods The growth inhibition of ATOon U266 cells and its IC50 were determined by MTT assay.Flow cytometry was used to evaluate the expression of cellular adhesion molecules,and apoptosis of U266 cell and cell cycle were also analyzed by FCM.Changes(ofCXCR4,)c-Myc,Rb,Bax/bcl-X_L,RANK-L,Cyclin D1 and VEGF gene were detected by RT-PCR.(Results)ATO could inhibit the proliferation of U266 in dose-and time-dependent manner.Cell(cycle) analysis showed that ATO induced most of a G_0/G_1 phase arrest and increased apoptosis of early stage in U266 cell.After ATOtreatment,expressions of adhesion molecules,especially the CD11a(increased) significantly.RT-PCR showed that CXCR4,c-Myc and bcl-X_L mRNA were significantly down-regulated after incubation with ATO,but there were no changes of RB,Cyclin D1,VEGF,Bax and RANKL genes during treatment.Conclusion ATOnot only induced apoptosis of U266 by down-regulation of c-Myc and bcl-X_L genes,but also arrested cells in G_0/G_1 phase,impacted adhesion molecules expression and homing of U266 through CXCR4.