Proteasome inhibitor bortezomib inducing apoptosis of K562 cells not affected by bone marrow mesenchymal stem cells in vitro / 中国实验血液学杂志

ABSTRACT

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 cells, 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 bortezomib 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.