硼替佐米体外诱导K562细胞凋亡的作用不受骨髓间充质干细胞的影响

Proteasome Inhibitor Bortezomib Inducing Apoptosis of K562 Cells not Affected by Bone Marrow Mesenchymal Stem Cells In Vitro

本研究探讨蛋白酶体抑制剂硼替佐米在有或无骨髓间充质干细胞(m esenchym al stem cells)条件下对白血病细胞株K562促凋亡作用,以及对M SC和K562细胞的黏附分子VCAM-1表达的影响。建立M SC和K562细胞的共培养体系,以终浓度为50nm o l/L的硼替佐米处理K562细胞4-24小时,应用Annex in-Ⅴ/PI双染法检测K562细胞凋亡,半定量RT-PCR检测VCAM-1mRNA的表达。结果显示,硼替佐米可诱导K562细胞凋亡,并呈现时间依赖性;共培养组凋亡细胞比例与单独培养组相比无显著差异;K562细胞与M SC共培养可诱导K562细胞表达VCAM-1,M SC在共培养前后表达VCAM-1无明显变化。硼替佐米作用24小时后,K562细胞表达VCAM-1消失,M SC表达VCAM-1明显下降。结论:硼替佐米在M SC存在的情况下依然可诱导白血病细胞凋亡,提示硼替佐米可拮抗M SC对白血病细胞的保护作用。

The study was aimed to investigate the effects of proteasome inhibitor bortezomib on the apoptosis of K562 cells in the presence of bone marrow mesenchymal stem ceils, and explore its effect on expression of adhesion molecule VCAM-1 of both MSC and K562 cells. The K562 cells were co-cultured in direct contact with MSC, while the control cells were just cultured alone. Bortezomib was administered at a final concentration of 50 nmol/L. Cell apoptosis was assayed by flow cytometry with Annexin-V/PI double staining kit. The VCAM-1 gene expression was determined by reverse transcription polymerase chain reaction （RT-PCR）. The results indicated that hortezomib could induce apoptosis of K562 cells in a time-dependent manner. K562 cells growing on the layer of MSC demonstrated the similar sensitivity to apoptosis induction of bortezomib. K562 cells which did not express VCAM-1 originally were induced to express VCAM-1 mRNA when co-cultured with MSC. This effect could be abrogated by bortezomib treatment. Furthermore, bortezomib significantly downregulated the VCAM-1 expression of MSC . It is concluded that the proteasome inhibitor bortezomib can induce apoptosis of K562 cells even though in presence of the MSC layer.