[Inducing-apoptosis effect of bortezomib on acute monocytic leukemia cell SHI-1 and its influence on expressions of Bcl2l12, Bcl-2 and Bax genes].

This study was aimed to explore the effect of bortezomib on proliferation and apoptosis of acute monocytic leukemic cells SHI-1 and the function of Bcl-2 gene family including Bcl2l12, Bcl-2 and Bax in its apoptosis. SHI-1 cells were cultured and treated with bortezomib of different concentrations for different time. MTT assay was used to detect the proliferation and apoptosis, Annexin-V staining, mitochondrial transmembrane potential (DeltaPsim) and DNA aga-rose gel electrophoresis were used to investigate apoptosis of SHI-1 cells. RT-PCR was used to analyze the levels of Bcl2l12, Bcl-2 and bax mRNA in SHI-1 cells treated with bortezomib for 0, 6, 12 and 24 hours. The results showed that bortezomib inhibited the proliferation of SHI-1 cells in time-and doze-dependent manners, the IC(50) at 24 and 48 hours were 54.13 nmol/L and 5.45 nmol/L respectively. Bortezomib could induce apoptosis of SHI-1 cells in time-dependent manner, increase expression of Annexin-V positive cells, decrease DeltaPsim of SHI-1 cells and result in DNA fragmentation and morphologic changes of apoptosis. RT-PCR showed that Bcl2l12 mRNA expression was up-regulated, bcl-2 mRNA expression was down-regulated and bax mRNA expression was not changed obviously. It is concluded that bortezomib inhibits the proliferation of SHI-1 and induces apoptosis in which Bcl2l12 and Bcl-2 gene can be ones of the main genes taking part in.