The Effect Of Asparaginase On Proliferation Inhibition Of Different Leukemia Cells And Dynamic Detection Of Childhood ALL Fusion Gene

Objective To explore effects and differences of L-asp on Jurkat,K562,K562/ADM cells proliferation inhibition and cell cycle in vitro.Methods Jurkat,K562 and K562/ADM cells were cultured in vitro,and L-asp interefered with these cells in logarithmic growth phase.Jurkat cells were treated with different concentrations of L-asp(0.02U/ml,0.1U/ml,0.5U/ml,2.5U/ml,12.5U/ml)whlie K562 cells and K562/ADMcells with L-asp(0.1U/ml,1U/ml,10U/ml,100U/ml,1000U/ml)for24h,48 h and 72 h.The proliferation inhibition of leukemia cells were detected by CCK-8assays.The effects of L-asp on different leukemia cell cycle were detected by flow cytometry.Results 1.(1)The proliferation inhibition of Jurkat,K562 and K562/ADM with different concentrations of L-asp were gradually increased for the same time(P<0.01).The proliferation inhibition of Jurkat,K562 and K562/ADM treated for 24 h,48h,72 h with same concentration of L-asp were gradually increased(P<0.01).(2)The proliferation inhibition of K562 and K562/ADM cells had no difference with 0.1U/ml of L-asp for24 h,48h(P>0.05).The proliferation inhibition of K562/ADM cells was higher than K562 cells with others concentration of L-asp and time(P>0.05).(3)The sensibility of Jurkat cells to L-asp was higher than K562 cells and K562/ADM cells while K562/ADM cells was higher than K562 cells.2.The IC50 of Jurkat,K562,K562/ADM cells on 24 h were 0.62U/ml,766.34U/ml,16.10U/ml;the IC50 of these cells on 48 h were 0.11U/ml,399.55U/ml,6.17U/ml;the IC50 of these cells on 72 h were 0.03U/ml,308.19U/ml,1.50U/ml.3.(1)Comparaed with control group,L-asp had effects on G0/G1 phase of Jurkat,K562 and K562/ADM cells.(2)The percent of G0/G1 phase in Jurkat,K562 and K562/ADM cells with different concentrations of L-asp were gradually increased for the same time(P<0.01).The percent of G0/G1 phase in Jurkat,K562 and K562/ADM cells treated for 24 h,48h,72 h with same concentration of L-asp were gradually increased(P<0.01).(3)The percent of G0/G1 phase in K562/ADM cells was higher than K562 cells with same concentration of L-asp and time(P>0.05).(4)The effect of G0/G1 phase in Jurkat cells was greater than K562 cells and K562/ADM cells while K562/ADM cells was greater than K562 cells.Conclusion In vitro,L-asp can inhibit the proliferation of Jurkat,K562 and K562/ADM cells,and different leukemia cells has different sensibility to L-asp.These leukemia cells can be inhibited in G0/G1 phase,and different leukemia cells received different effects.Objective To study clinical significance of the dynamic changes of fusion gene expressions in the treatment in children acute lymphoblastic leukemia(ALL).Methods We studied the dynamic changes of fusion gene expressions by gene magnifications.84 children had fusion gene without expression,and 84 children had fusion gene expression,including TEL-AML1,EVI1,others(BCR-ABL,E2A-PBX1,SIL-TAL1,MLL rearrangement)and double fusion gene expression.The results were analysed combined with multi-clinical factors in 168 ALL patients by chi-square test,Kaplan-Meier analysis and COX proportional hazards regression model.Results 1.The overall survival(OS)rate in ALL patients with fusion gene expressions had no statistical significance(c 2=3.3603,P>0.05)while EFS had statistical significance(c2=14.6151,P<0.05).The event free survival(EFS)rates in TEL/AML1 expression group was higher than that in the patients without fusion gene expressions and in OTHERS expression group(c2=6.877?3.926,P<0.05).2.The 3-year EFS rates in TEL/AML1 sustained non-expression group and DOUBLE sustained non-expression group were higher than that without non-expression(c2=8.925?6.091,P<0.05)while EVI1 expression group and DOUBLE expression group had no difference(c2=1.529?0.667,P>0.05).3.The 3-year EFS rate in ALL patients whose fusion gene turning negative within the first year had no difference with that not turning negative within the first year(c2=0.815,2.745,0.004,0.667,P>0.05).4.The 3-year EFS rates in fusion without non-expression whose age older than 10 years,T cell line,high-risk clinical classification,MRD on the 15 th,MRD on the 33 th more than 10-2 were obviously higher(c2=4.542~7.974,P<0.05).5.Multivariate analysis suggested that the high-risk factors that affected the prognosis were age older than 10 years(95%CI 2.063~25.901,P<0.05),T cell line(95%CI 1.009~22.084,P<0.05).Conclusion Dynamic monitoring fusion gene expressions' changes has great helpful in the prognosis and individual treatment in ALL patients.