The Effect Of Imatinib Mesylate Therapy On Ph Chromosome And Bcr/abl Gene Expression In Patients With CML

Objective:To detcet the changes of Philadelphia(Ph) chromosome and bcr/abl fusion gene expression before and after imatinib mesylate(STI571,Gleevec) therapy in Ph chromosome-positive Chronic Myeloid leukemia(CML).A related goal was to evaluate the prognosis and therapeutic effect in those patients treated with imatinib mesylate.Methods:A total of 11 Ph chromosome-positive CML patients were enrolled into our study.Chromosome specimens preparation of bone mallow cells were made using direct and short term culture.Total RNA was extracted by the Trizol Reagent method and quantified spectrophotometrically.The karyotype and bcr/abl fusion genes expression before and after imatinib mesylate therapy were analyzed by R-banding and semi-quantitative reverse transcriptase polymerase chain reaction(RT-PCR),respectively.Results:Among the 11 patients,7 cases for whom treated with imatinib mesylate for 3 months,achieved a complete cytogenetic remmision(CCyR) without any Ph chromosome-positive cells.One case in chronic phase treated for 2 months,whose Ph chromosome positive rate was 30%,achieved major cytogenetic remmision(MCyR).One case in blast crisis phase treated for 6 months,its Ph chromosome positive rate reduced to 70%.One case in accelerated phase treated for 12 months,its Ph chromosome positive rate was 60%.Another case in chronic phase treated for 1 month,the chromosome positive rate was still 100%.Bcr/abl fusion gene expressions after treated with imatinib mesylate were decreased obviously compared with that pretreatment in all cases(t=3.774, 5.13;p＜0.01).Conclusions:Imatinib mesylate can effectly make the Ph chromosome became negative in 63.6%patients of chromic phase chromic myeloid leukemia.Imatinib mesylate was active against Ph chromosome-positive CML,and was able to effectually decrease the expression levels of bcr/abl fusion gene.The detection of bcr/abl fusion gene takes an important role in monitoring the therapeutic effect of imatinib mesylate in CML patients with CCyR.