砷剂诱导多发性骨髓瘤细胞socs-1基因去甲基化作用的研究

本研究探讨三氧化二砷（As2O3）对人多发性骨髓瘤细胞株U266、RPMI8226细胞内socs-基因甲基化状态的影响。用MTT法观察As2O3对骨髓瘤细胞增殖情况的影响，采用甲基特异性PCR法检测As2O3作用前后骨髓瘤细胞株U266、RPMI8226 socs-1基因的甲基化状态，以实时定量PCR技术定量检测细胞株给药前后socs-1基因mRNA的表达变化，流式细胞技术检测As2O3诱导的骨髓瘤细胞的凋亡情况。结果表明：人骨髓瘤细胞株U266、RPMI8226均存在不同程度的socs-1基因CpG岛甲基化，socs-1基因不表达的现象。As2O3作用72小时后socs-1基因甲基化程度明显减弱或消失，socs—1基因在mRNA水平上表达明显增强，与各野生型细胞株相比，差异具有显著性P〈0．05），且细胞生长抑制明显，早期、晚期细胞凋亡比率明显升高，并呈现剂量依赖性。结论：As：03可诱导socs—1基因甲基化状态的改变，使基因表达上调，恢复其活性，这为进一步阐明As2O3诱导骨髓瘤细胞凋亡的可能机制和As2O3治疗多发性骨髓瘤的可能机制提供新的思路和新的研究方向。

Arsenic Trioxide Induces socs-1 Gene Demethylation in Myeloma Cell Lines

The aim of this study was to explore the effect of arsenic trioxide (As(2)O(3)) on the methylation status of socs-1 gene in multiple myeloma cell lines U266, RPMI8226. The cell viability was assayed by MTT method. The methylation status of socs-1 gene was detected by methylation specific PCR. The expression of socs-1 gene mRNA was determined with real-time PCR. The cell apoptosis was analyzed by flow cytometry. The results indicated that hypermethylation of CpG island of socs-1 gene was observed without expression of socs-1 in myeloma cell lines U266, RPMI8226. The expression of socs-1 gene mRNA in each myeloma cell line increased significantly after exposure to As(2)O(3) for 72 hours as compared with the cell lines of wild type (p < 0.05). And cell proliferation was significantly inhibited, both early apoptosis and later apoptosis ratios increased in dose-dependent manner. It is concluded that As(2)O(3) may induce socs-1 demethylation and up-regulate the expression of the gene. This study provides a new thought and direction for exploring possible mechanism of cell apoptosis induced by As(2)O(3) and multiple myeloma treatment by As(2)O(3).