As2O3对多发性骨髓瘤细胞的细胞毒作用的机制研究

背景与目的:多发性骨髓瘤(multiple myeloma,MM)是恶性浆细胞疾病,目前仍难以治愈;已有研究证明三氧化二砷(arsenic trioxide,As2O3)在体外能够抑制骨髓瘤细胞增殖并诱导其凋亡.本研究拟探讨As2O3对多发性骨髓瘤细胞的可能作用机制.方法:采用MTr法检测As2O3对5株骨髓瘤细胞U266、SKO-007、LP-1、HS-Sultan和KM3的抑制作用,求出其IC50,同时研究维生素K3(vitamine K3,VK3)、N-乙酰半胱氨酸(N-acetyl-cysteine,NAC)和还原型谷胱甘肽(glutathione,GSH)对As2O3的协同或拮抗作用;利用光学比色法测定不同浓度As2O3作用后的5株骨髓瘤细胞以及As2O3与VK3、NAC或外源性GSH共同作用后的U266细胞的GSH含量,对细胞GSH含量与IC50进行相关性分析.结果:As2O3对5株骨髓瘤细胞均有增殖抑制作用,但其敏感性不同,细胞内GSH含量与其IC50正相关(r=0.87,P＜0.05);氧化剂VK3与As2O3有明显协同作用,抗氧化剂NAC和GSH对As2O3具有拮抗作用.结论:As2O3可能是通过与细胞内的含巯基化合物结合,降低细胞内GSH含量,从而诱导骨髓瘤细胞凋亡.

Mechanism of arsenic trioxide-induced cytotoxicity on multiple myeloma cells

BACKGROUND &OBJECTIVE: Multiple myeloma (MM), a plasma cell tum or , is difficult to cure by now. Previous study showed that As2O3 could inhibit th e proliferation and induce the apoptosis of myeloma cell in vitro. The aim of th is study was to explore the possible mechanism of arsenic trioxide (As2O3) on mu ltiple myeloma cells. METHODS: The cytotoxic effects of As2O3 on five myeloma ce ll lines U266, SKO-007, LP-1, HS-Sultan, and KM3 were examined using MTT bioa ssay, and the concentration of 50%growth inhibition (IC50) was calculated. The synergistic or antagonistic effects of menadione (VK3), N-acetyl-cysteine (NAC ), and reduced glutathione (GSH) combined with As2O3 were also examined. The cel lular GSH levels in five MM cell lines and its changes in U266 cells after treat ed with As2O3, VK3, NAC, and exogenous GSH were determined by colorimetric assay , and the relationship between IC50 and cellular GSH levels was analyzed. RESULT S: As2O3 inhibited the proliferation of all five myeloma cells, but with differe nt sensitivity. GSH contents in five MM cells were correlated with its IC50 sign ificantly (r=0.87,P< 0.05). Oxidant VK3 had significant synergistic effect with As2O3, and antioxidants NAC and GSH partly blocked the growth inhibition of As2O 3. Both As2O3 and VK3 decreased the GSH contents, NAC and GSH increased them con trarily. CONCLUSION: One of the mechanisms of effect of As2O3 on myeloma cells m ay be through decreasing the cellular GSH levels and inducing myeloma cell apopt osis.