锌指蛋白ZFX在儿童B系急性淋巴细胞性白血病中的表达及意义

目的：研究儿童B系急性淋巴细胞性白血病（B-ALL）患者骨髓单个核细胞中X染色体耦联锌指蛋白（ZFX）的表达及其与白血病预后的关系。方法：通过Western blot方法检测白血病细胞株（REH、HL-60、NB4、K562）中ZFX蛋白的表达；利用PCR方法扩增获得全长ZFX，并测序验证；通过实时定量PCR检测82例初发B-ALL儿童骨髓样本，24例B-ALL缓解期样本，以及64例骨折或先天性心脏病手术患儿样本(对照组)ZFX的表达；并根据治疗3年内有无骨髓或中枢神经系统复发分为预后好组和预后差组，比较两组患儿初发时骨髓中ZFX mRNA的表达水平。结果：ZFX蛋白在白血病细胞株REH、HL-60、NB4和K562中均有表达。初发ALL组骨髓中ZFX mRNA表达高于对照组（P＜0.01）；ALL缓解组ZFX mRNA表达明显低于ALL初发组（P<0.01）；预后差的ALL患儿初发骨髓中ZFX mRNA的表达高于预后好的患儿（P＜0.05）。结论ZFX在儿童B-ALL中高表达，且预后差组表达相对较高，提示它可能在B-ALL预后判断中有重要意义。

Expression of zinc finger protein X-linked in childhood B lineage acute lymphoblastic leukemia

Objective To study the expression of zinc finger protein X-linked(ZFX) in bone marrow mononuclear cells(BMMCs) of children with B lineage acute lymphoblastic leukemia(B-ALL)and its relationship with prognosis.Methods The expression of ZFX in human leukemia cell lines(REH,HL-60,NB4 and K562) was measured by Western blot.ZFX gene was cloned by PCR from one patient and DNA sequencing technology was used to confirm it.Real-time PCR was used for detecting ZFX mRNA expression in the BMMCs of 82 children with newly-diagnosed B-ALL,24 children with complete remission(CR) after induction therapy and 64 control children(fracture or congenital heart disease patients).According to the presence of bone marrow or central nervous system relapse during a follow-up of 3 years,the patients were identified as having a good or poor prognosis.Their ZFX mRNA levels in BMMCs at diagnosis were compared.Results ZFX protein was expressed in human leukemia cell lines REH,HL-60,NB4 and K562.ZFX mRNA expression was significantly higher in the newly-diagnosed ALL group than in the control group(P<0.01).ZFX mRNA expression in the ALL CR group was significantly reduced compared with the newly-diagnosed ALL group(P<0.01).Children with a poor prognosis had significantly higher ZFX mRNA levels at diagnosis than those with a good prognosis(P<0.05).Conclusions ZFX is over-expressed in children with B-ALL and its levels are higher in those with a poor prognosis than those with a good prognosis,which suggests that ZFX is important in the prognosis evaluation of B-ALL.