| Objective:To evaluate the prognostic impact of AML1/ETO fusion gene detection qualitatively and quantitively in patients with acute myeloid leukemia with t(8;21)(q22;q22)[t(8;21)-AML].Methods:The results of AML1/ETO fusion gene detection were analyzed from52t(8;21)-AML patients (qualitative analysis of32patients and quantitive analysis of20patients) during the time of first diagnosis, therapeutic process and follow-up, to find the relationship between the change of AML1/ETO fusion gene expression and the patients’relapse and survival.Results:The negative rate of AML1/ETO from32patients at our check point/regions (getting complete remission,0-3,3-6,6-12,12-18,18-24and>24months from CR) were as follows:20%,46.88%,71.88%,71.88%,72.41%,95.45%and100%, respectively. The relapse of patients from different groups (AML1/ETO positive or negative) at every checkpoint/region was as bellow:when getting CR (relapsing patients/all patients of the group),3/20vs.3/5, P=0.07;0-3months from CR,3/17vs.3/15, P=1.0;3-6months from CR,2/9vs.4/23, P=1.0;6-12months from CR,5/9vs.1/23,P=0.003;12-18months from CR,5/8vs.0/21, P=0.000;18-24months from CR,0/1vs.0/21;>24months from CR, all17patients were negative,0/17. Survival analysis showed that the AML1/ETO results of these three check point/regions (when getting CR,6-12,12-18months from CR) were related to survival. Three years relapse free survival (RFS) were85%vs40%,P=0.037;44.4%vs95.5%,P=0.000;37.5%vs100%, P=0.000;3years overall survival (OS) were respectively:81.4%vs40%, P=0.018;25%vs95.7%P=0.001;20%vs100%P=0.000.Quantitative analysis of AML1/ETO fusion gene showed that there was no relationship between the initial copy number at diagonosis and relapse rate. Additional data reflected that the declining degree of AML1/ETO copies when getting CR(<2log or≥2log) influenced RFS;1year RFS was40%vs100%, P=0.02. The copy number at3months and5/6months after CR were related to relapse:at3months after CR, the copy number was300vs.10.5copies/104ABL in relapsed and non-relapsed group(P=0.039), and2161vs.12copies/104ABL at5/6months after CR(P=0.004). And rising of AML1/ETO copies after CR(≥0.5log) also affected RFS;1year RFS was58.3%vs100%, P=0.017.Conclusion:Qualitatively monitoring AML1/ETO fusion gene can predict the prognosis of t (8;21)-AML patients. Patients achieve negative results after6monthes from CR may have longer survival time. In quantitative detection, the larger declined degree of AML1/ETO copies at the time of getting CR and constantly keeping low level during monitoring indicates better survival. Objective:To investigate the regulation of WT1by HtrA2(one of the high temperature requirement family members) in K562cells, and observe the influence of this regulation in cytobiological function and its related mechanisms.Methods:The expression of WT1and HtrA2in mRNA and protein level after drug and HtrA2inhibitor (UCF-101) treatment was detected with RQ-PCR and Western blot method. After treatment with drugs and UCF-101, the proliferative function of K562cells was detected with MTT method and apoptosis by flow cytometry after labeled with Annexin V and PI. Protein level in signal pathway was analyzed with Western blot in K562cells after treated with drugs and UCF-101. And also RQ-PCR and Western blot method were used in the detection of WT1and HtrA2expression in CML patients with different disease status.Results:In K562cells, imatinib treatment could activate HtrA2gene at transcription level, while WT1gene was down-regulated at the same time. After HtrA2inhibitor (UCF-101) treatment, the down-regulated WT1level increased gradually. In protein level, both imatinib and homoharringtonine (HHT) could induce the increase in HtrA2protein (the effect was weaker in HHT); and imatinib down-regulated WT1protein level greatly at the same time. After HtrA2was inhibited by UCF-101, WT1protein level decreased temporarily and then increased eventually. In function analysis, both imatinib and HHT can induce apoptosis in K562cells, but this effect can be attenuated by HtrA2inhibitor which leaded to the up-regulation of WT1protein level. But UCF-101did not obviously change the proliferation inhibition caused by imatinib and HHT. In signal pathway analysis, imatinib and HHT could both activate the p-38MAPK signal pathway in K562cells, and UCF-101could inhibite this kind of activation. Imatinib inhibited erkl/2pathway greatly and persistently, but UCF-101had no notable effect in the inhibition of erkl/2pathway. In CML patients’analysis, WT1gene expression level was higher in the chronic phase of newly diagnosed patients, lower in patients with CCyR, and increased in patients in accelerating phase and blast crisis. The tendency of HtrA2gene expression was opposite. In paired sample analysis (before and after TKI treatment), HtrA2protein was higher and WT1 protein lower after treatment, which was consistent with the results in K562cells.Conclusion:Regulation of WT1by HtrA2occurs in K562cells, and this regulation can influence the apoptosis of K562cells under the stress caused by drugs. p-38MAPK signal pathway, which plays important part in cell apoptosis, is a downstream pathway of this regulation. |
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