The Effect And The Mechanisms Of Bortezomib And Homoharringtonine Combined Actining On K562 Cells

Objective:1. Explore the effects of BTZ alone, HHT alone and BTZ plus HHT on proliferation and apoptosis in K562 cells.2. Explore the relationship between the underlying mechanisms of the effect of BTZ plus HHT actining on K562 cells and the level of Bcl-2,Bax and Mcl-1protein.Methods and experiment groups:The K562 cells were divided into 4 groups by different treatments:(1)BTZ(20nmol/L)(2)HHT(40ng/m L)(3)BTZ(20nmol/L)+HHT(40ng/m L)(4)Control1. To examined the proliferation rates of K562 cells in each group via MTT.2. To examined the early apoptosis rates of K562 cells in each group via Annexin V-FITC/PI staining.3. To examined the level of proteins of Bcl-2, Bax and Mcl-1 in each group via Western blot analysis.Results:1. The inhibit proliferation rates of K562 cells increased along with the increasing concentration of BTZ(compared with the control group, p<0.05) in the range of0~160nmol/L. At the same concentration of BTZ,the inhibit proliferation rates of K562 cells increased along with the extending time(compared with the control group, p<0.05) in the range of 24~72h. IC50(24h) was 91.36nmol/L, IC50(48h)was 44.25nmol/L,IC50(72h) was 20.34nmol/L.2. The inhibit proliferation rates of K562 cells increased along with the increasing concentration of HHT(compared with the control group, p<0.05) in the range of0~320ng/ml. At the same concentration of HHT,the inhibit proliferation rates of K562 cells increased along with the extending time(compared with the control group, p<0.05) in the range of 24~72h.IC50(24h) was 148.92ng/ml,IC50(48h)was 61.48ng/ml,IC50(72h) was 35.65ng/ml.3. The inhibit proliferation rates of K562 cells treated with BTZ(20nmol/L) at 24 h,48h, 72 h were 24.29±1.38、38.36±0.97 and 49.30±1.66 respectively(compared with the control group, p<0.001). The inhibit proliferation rates of K562 cells treated with HHT(40ng/m L) at 24 h,48h,72 h were 29.10±1.54,39.78±1.86 and50.71±2.26(compared with the control group, p<0.001). The inhibit proliferation rates of K562 cells treated with BTZ plus HHT at 24 h, 48 h, 72 h were48.58±2.18,69.87±1.86 respectively(compared with the control group,p<0.001).The rates compared with statistical significance among BTZ, HHT and combined group(p<0.01).Interaction analysis showed that the proliferation inhibition rates of combined group at different time were IR(BTZ+HHT) >IR(BTZ)+IR(HHT)-IR(BTZ)*IR(HHT).4. The early apoptosis rates of K562 cells in combined group was increased significantly compared with BTZ and HHT alone group(p<0.05).5. The level of Bcl-2 protein of K562 cells in combined group was lower than BTZ and HHT alone group(p<0.05).6. The level of Bax protein of K562 cells in combined group was higher than BTZ and HHT alone group(p<0.05).7. The Order of the Mcl-1 protein’ level of K562 cells in 4 groups was BTZ >Control>BTZ plus HHT>HHT(comparison among groups,p<0.05).Conclusions:1. The BTZ and HHT alone exerted anti-proliferative activity against K562 cells in vitro.2. The BTZ and HHT alone could induced apoptotic death of K562 cells in vitro.3. The combination of BTZ and HHT could induced apoptotic death of K562 cells via suppression of Bcl-2 protein.4. The combination of BTZ and HHT could induced apoptotic death of K562 cells via upregulation of Bax protein.5. HHT could increase the sensitivity of K562 cells to BTZ by down regulating the expression of Mcl-1 protein.