Objective To explore the apoptosis effect induced by bortezomib combined with homoharringtonine or arsenious acid in HL-60 cell line and the mechanism.Methods Cell' s apoptosis was demonstrated by MTT assay and Hoechst33342 staining.Expression of bcl-2,Caspase-9,Caspase-3 and PARP protein was detected by Western blot.Results HL-60 cells' apoptosis could be induced by bortezomib,homoharringtonine and arsenious acid respectively.Proliferation inhibition of HL-60 cells could be enhanced significantly when treated by bortezomib combined with homoharringtonine or arsenious acid compared with treated by any of the three drugs alone (P ＜ 0.05).At the same time morphology shows the apoptosis induced by drugs combined is more obviously than by one drug.Western blot showed bcl-2 protein was down-regulated and Caspase-9,Caspase-3 and PARP proteins were all cleaved activation when cells were treated by 15 μmol/ L arsenious acid alone,but only cleaved activation of PARP and down-regulation of bcl-2 protein be detected when cells were treated with 30 nmol/L homoharringtonine alone,expression of Caspase-9 and Caspase-3 had no change compared with the control.The changes of associated proteins were paralleled with the cell' s apoptosis when treated with combined drugs.Conclusion HL-60 cells' apoptosis effect is inhanced significantly when bortezomib combined with homoharringtonine or arsenious acid.Arsenious acid and bortezomib can inhibit caspase signaling pathway and down-regulate the expression of bcl-2 protein together,but homoharringtonine and bortezomib can only down-regulate the expression of bcl-2 protein and induce cleaved activation of PARP together.

Objective To explore the effect and mechanism of Cyclosporin A (CsA) and cholic acid on reducing the human liver cell damage induced by α-amanitin (AMA).Methods According to the previous research results,the minimum hepatocellular survival concentration against αt-AMA (1.4 g/L),the experiment was conducted in 5 groups:control group,damage group,glycochenodeoxycholic acid group,CsA group,and CsA combined with cholic acid group (CsA+ taurocholic acid,CsA+ chenodeoxycholic acid,CsA+ glycocholic acid,CsA+ glycochenodeoxycholic acid,and CsA+ taurochenodeoxycholic acid).For each group,there were 3 time points for observation (24 h,48 h and 72 h after attacking),CsA and CsA+ glycochenodeoxycholic acid was used to protect hepatocytes,respectively,and morphological changes in cells were observed with inverted phase contrast microscope,and the live cells were counted by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) method,and aspertate aminot ransferase (AST) and alanine aminotransferase (ALT) in the culture supernatant were detected by biochemical method.Results Compared with the control group,hepatocellular growth in the injury group was obviously suppressed,with progressive cellular apoptosis and significantly decreased absorbance value of MTIT (0.345 ± 0.021);the activity of AST and ALT increased gradually,reaching the highest after 72 h [(98.4 ± 6.7) U/L and (116.2 ± 9.5) U/L,respectively].Compared with injury group,broken organelles decreased significantly and absorbance value elevated in glycochenodeoxycholic acid group,CsA group and CsA combined with cholic acid group,and at each time point,the highest absorbance value in the CsA+ taurochenodeoxycholic acid group [the highest was (0.656 ± 0.014),P ＜ 0.05];at the same time,the activity of AST and ALT didn't increase obviously,at each time point,the lowest in CsA+ taurochenodeoxycholic acid group [the lowest was (22.3 ± 6.2) U/L and (20.2 ± 5.4) U/L,P ＜ 0.05,respectively].Conclusions CsA,as well as cholic acid,can protect human liver cells from the attack of α-AMA.The mechanism may be CsA,as an organic anion transfer peptide in humans (OATP1B1 and OATP1B3) suppressant,inhibits the absorption of α-AMA.The joint application of CsA and taurochenodeoxycholic acid is superior to the single OATP substrate or inhibitor.