Mechanisms Of MDM2-P53 Pathway In K562/G01 Cell’s Apoptosis Induced By Triptolide

Objective:Chronic myelogenous leukemia(CML) is a kind of malignant hematological diseases,characteristics of Philadelphia chromosome positive(Ph),the long arm to chromosome 22 and 9 long arm interaction to chromosome translocation resulting expression of BCR- ABL fusion gene and corresponding protein.IM is the first generation of small molecule tyrosine kinase inhibitor, it can inhibit the activity of BCR-ABL, is the main method for the treatment of CML.It had changed the therapeutic effect and prognosis of chronic myeloid leukemia significantly.However the 20%-30%patients have occured resistant or intolerant.Triptolide received attention because of its potential to resist cancer.Recently,A study have reported that triptolide can influence the MDM2-p53 related gene expression to induce acute lymphoblastic leukemia cell apoptosis. Whether have the same mechanism of apoptosis in the chronic myeloid leukemia resistant imatinib cells(K562 / G01)? Our study observed by the method of experments TP on K562/G01 cell apotosis inducing and effect of MDM2/P53 pathway in vitro,Discuss the possible antitumor mechanism and provide a new perspective for the treatement of CML.Method:1.MTT was used to determine the inhibitory effect of TP at different concentrationsat and different time on K562/G01 cells;2. apoptosis rate was measured by flow cytometry at 12 h and 24h;3. The transcription level of BCR/ABL,XIAP,MDM2,P53 of K562/G01 cells was measure by real time-PCR.Result:1.MTT assay showed that cultured K562 / G01 cells by different time(12h, 24 h,48h) in different concentrations of TP(10 nmol / L, 20 nmol / L, 40nmol/l, 80nmol/l and100 nmol / L), The cell proliferation inhibition rate varies with the concentration increase and time increased(P < 0.05) and dispaly the time and dose dependent;2. The apoptosis results showed that cultured K562/G01 cells bydifferent time(12h,24h) in different concentrations of TP( 20 nmol / L, 40nmol/l), The cell apoptosis rate varies with the concentration increase and time increased(P < 0.05)and in a time- and dose-dependent manner;3. The results of Real time fluorescence quantitative polymerase chain reaction(RT-PCR) assay results showed that cultured K562/G01 cells in different concentrations of TP( 20 nmol / L, 40nmol/l), The expression of p53 mRNA is increased and the expression of BCR/ ABL,XIAP,MDM2 and P53 mRNA are deseased(P < 0.05)and in a dose-dependent manner.conclusion:1.TP can inhibition of K562/G01 cell proliferation in time- dose dependent manner;2.TP can induce the apoptosis of K562/G01 cells in a time dose dependent manner;3.TP can decrease the expression of XIAP, MDM2, BCR/ABLmRNA,, and increase the expression of P53 mRNA in a dose-dependent manner. Triptolide may affect the proliferation and apoptosis of K562/G01 cells by affecting the expression of related genes in the XIAP-MDM2-P53 pathway.