硼替佐米对多发性骨髓瘤细胞凋亡及分子伴侣BiP表达的影响

本研究旨在探讨蛋白酶体抑制剂硼替佐米对多发性骨髓瘤细胞株NCI—H929（H929）的凋亡诱导作用及其对H929细胞中分子伴侣BiP表达的影响。以不同浓度硼替佐米处理H929细胞24小时后，采用Annexin V—FITC／PI双染联合流式细胞术检测靶细胞凋亡率；用RT—PCR和Westernblot检测靶细胞BiP mRNA和BiP蛋白的表达。结果表明：不同浓度硼替佐米（20、40、80nmol／L）均可诱导靶细胞凋亡，凋亡率分别为（15．73±0．67）％、（27．83±1．26）％7t．（44．17±2．25）％，呈剂量依赖性，且均显著高于未处理组（1．21±0．07％）（P〈0．05）；经不同浓度硼替佐米处理后，靶细胞BiPmRNA和BiP蛋白水平均高于未处理组，且二者变化一致；在相近的促凋亡条件下（凋亡率约40％-50％），标准内质网应激诱导剂brefeldin A（500ng／ml，24小时）对H929细胞BiP mRNA和BiP蛋白表达的上调作用与硼替佐米（80nmol／L，24小时）基本一致。结论：硼替佐米诱导H929细胞凋亡并伴有分子伴侣BiP mRNA和BiP蛋白表达上调，表明硼替佐米诱导的H929细胞凋亡极可能涉及内质网应激反应。

Bortezomib-induced BiP Expression and Apoptosis in Multiple Myeloma Cells

This study was aimed to explore the effect of bortezomib on the apoptosis and expression of the molecular chaperon BiP in human multiple myeloma cell line NCI-H929 （H929）. After treatment of H929 cells with different concentrations of bortezomib for 24 hours, cell apoptosis was assayed by flow cytometry with Annexin V-HTC/PI staining, and the expression levels of BiP mRNA and protein were detected by RT-PCR and Western blotting analysis. The results showed that bortezomib of different concentrations （20, 40 and 80 nmol/L） induced apoptosis of H929 cells in dose-dependent manner, with apoptotic rates （ 15.73 ＋ 0. 67 ） %, （ 27. 83 ＋ 1.26 ） % and （ 44. 17 ＋ 2.25 ） % respectively, which were significantly higher than that in control （ 1.21 ＋ 0.07% ） （p 〈 0.05）. Bortezomib-induced upregulation of BiP mRNA levels was almost on a parallel with BiP protein when compared with control. Under the similar apoptosis-stimulating conditions with apoptotic rates varying from 40% to 50%, expression levels of BiP mRNA and BiP protein induced by the classical endoplasmic reticulum stressor Brefeldin A （500 ng/ml, 24 h） were almost consistent with those by bortezomib（80 nmol/L, 24 h）. It is concluded that bortezomib-induced apoptosis in/-/929 cells correlates closely with endoplasmic reticulum stress.