Effect Of Triptolide On The Proliferation And Apoptosis And On Wnt/β-catenin Pathway In Imatanib Resistant CML Cell

Objective:1.This experiment aims to investigate the impact of triptolide(TP) on the proliferation and apoptosis in imatanib resistant CML cell(K562/G01).2. To investigate the regulating effect of TP on Wnt/β-catenin signal pathway in imatanib resistant CML cell.3.To provide basic theoretical knowledge of experimental research for the clinical application of TP on the imatanib resistant CML patients.Methods:10,20,40,80nmol/L of triptolide were used in CML cells K562/G01 for corresponding 12,24 and 48 hours,then several indexes were detected.1.The cell growth inhibition rates were detected by Methyl thiazolyl tetrazolium(MTT)test.2.The apoptosis rates were assessed by Annexin V/PI double-staining method and Flow cytometry(FCM).3.The m RNA expressions of BCR-ABL,β-catenin and its down-stream targets Lef-1,cyclin D1 were analyzed by Real-time quantitative polymerase chain reaction(RT-PCR), respectively.Results:1.MTT test results showed that triptolide significantly inhibited K562/G01 cell growth ability.With increasing drug concentration and explosure time, there were significant increase in cell growth inhibition rates, owning dose-time dependence effect.In the same period of time, differences of cell growth inhibition rates between different concetration groups were statistical significant(p<0.05).The corresponding statistics were(22.62 ± 1.33)%,(51.41 ± 1.39)% in the 20,40 nmol /L of triptolide groups after 24 hours.2.The FCM results showed that induced apoptosis rates appeared to increase with the increasing drug concentration in a dose-dependent manner. After being treated with 0,20,40nmol/L TP for 24 hours,the early apoptosis rates were(2.54±0.50)%,(6.53±0.52)%,(9.54±0.68)%,respectively.Whereas the late apoptosis rates were(6.67±0.06)%,(6.91±0.14)%,(7.64±0.47)%,respectively.Difference between groups were significant(p<0.05).3.Meanwhile, PCR datas showed that the m RNA levels of BCR-ABL were decreased obviously in the treatment groups,compared with the control group, the m RNA levels of β-catenin and its down-stream targets Lef-1,and cyclin D1 were also decreased in a dose-dependent manner.Conclusion:1.The triptolide could inhibit the proliferation of K562/G01 significantly in a time-dose-dependent manner.2.The triptolide could also induce the apoptosis of K562/G01 significantly in a time-dose-dependent manner.3.Our datas indicated that the triptolide could inhibit the proliferation and induce the apoptosis of K562/G01,and the mechanism may be relateded to the blockade ofβ-catenin m RNA and its downstream targets,such as Lef-1,cyclin D1,in other words,related to the blockdade of Wnt/β-catenin signal pathway.