急性髓细胞白血病中婆罗双树样基因4的表达及其临床意义

Expression of SALL4 in acute myeloid leukemia and its potential clinical significance

目的探讨婆罗双树样基因4（SALL4）在急性髓细胞白血病（AML）中的表达及其临床监测意义。方法采用逆转录PCR、实时荧光定量PCR、细胞培养、流式细胞术、骨髓涂片及血细胞分析仪等技术检测了68例AML患者（急性期36例、缓解期32例）、30名健康对照者、AML细胞系Kasumi-1和THP-1中SALL4的表达水平，评价其与骨髓原始细胞数、外周血WBC、未染色大细胞（LUC）计数及骨髓白血病免疫表型CD34表达率的关系。动态观察5例AML患者化疗前后3个时间点（化疗前急性期、治疗中第2～3周、化疔后缓解期）SALL4的表达水平。结果急性期AML患者SALL4表达水平[69．01（17．20～120．28）]是缓解期AML患者SALL4表达水平[2．64（1．35—5．41）]的26倍，是健康对照组SALL4表达水平[1．14（0．50～1．62）]的61倍（Z=-6．48、-6．83，P均〈0．01）；缓解期AML患者SALL4表达水平是健康对照组的2．3倍（Z=-3．61，P〈0．01）。动态观察5例AML患者，SALL4基因表达水平随着治疗和病情缓解呈下降趋势，化疗前急性期、化疗中第2～3周和化疗后缓解期SALL4基因表达水平分别为79．74（33．76—89．09）、7．19（5．97～20．21）和3．40（1．44—15．53）。骨髓原始细胞数增高组、LUC计数增高组及CD34表达率增高组中SALL4表达水平分别为33．82（16．00～144．01）、30．70（23．75—72．50）、56.25（23，79～153．81），高于相应正常组的2．74（1．59～5．13）、5．71（2．52—22．40）、20．82（14．03—55．12），差异有统计学意义（Z=-4．64、-2．18、-3．66，P〈0．01或〈0．05）；外周血WBC计数增高组SALL4表达水平为89．26（23．75—154．34），高于相应的WBC计数正常组的3．86（2．03～6．01）和WBC计数减低组的6．66（2．51—17．06），差异有统计学意义（Z=-4．91、-4．21，P均〈0．01）；SALL4表达率与骨髓原始细胞数以及外周血WBC计数呈正相关（r=0．45、0．40，P均〈0．01）。结论成功建立了人SALL4基因表达水平的实时荧光定量PCR方法，SALL4表达有望成为监测AML病情和判断预后的新指标。

Objective To detect the expression of SALL4 in patients with acute myeloid leukemia （AML） and analyze its potential clinical significance. Methods Reverse transcription polymerase chain reaction and Real-time fluorescence quantitative reverse transcription polymerase chain reaction （FQ-RTPCR） was used to examine SALL4 expression in peripheral blood mononuclear cells （PBMCs） of 68 cases of AML including 36 cases in acute phase and 32 eases in remission phase, 30 healthy controls, Kasumi-1 cells and THP-1 cells. Then, flow cytometry, bone marrow smear and automated hematology analyzer were used to analyze the relationship between the SALL4 expression and blast cell counts in the bone marrow, peripheral white blood cell （WBC） counts, peripheral large unstained cell （LUC） , CD34 in blast cells. Further, the change of SALL4 level during pre-chemotherapy, chemotherapy （2^nd w to 3^rd w） and remission were investigated in 5 AML cases. Results The level of SALL4 expression in patients with AML in acute phase[ 69.01 （ 17.20-120. 28） ] was 26-fold and 61-fold high compared with that in remission phase [ 2.64 （ 1.35- 5.41） ] and in healthy control [ 1.14（0. 50-1.62） ] （Z = -6.48, -6. 83,P 〈0. 01）. The level of SALL4 expression in remission phase was 2.3-fold high compared with that in healthy control （ Z = - 3.61, P 〈 0. 01）. The expression level of SALL4 was decreased along with efficient chemotherapy in 5 AML cases in which SALL4 expression level was 79. 74 （ 33.76-89.09 ）, 7. 19 （5.97-20. 21 ） and 3.40 （ 1.44-15.53 ） during pre-chemotherapy, chemotherapy （2^nd w to 3^rd w） and remission, respectively. In groups of abnormal increased counts of blast cell, peripheral LUC% and CD34% , expression of SALL4 [ 33.82 （ 16.00- 144.01）, 30.70（23.75-72.50）and 56. 25（23.79-153.81 ）, respectively] were higher than that in groups of normal counts [ 2. 74 （ 1.59-5.13 ）, 5.71 （2. 52-22. 40） and 20. 82 （ 14. 03-55.12）, respectively ] （ Z = -4. 64, -2. 18, -3.66,P 〈0. 01 or P 〈0. 05）. The expression of SALL4 in the group of increased WBC counts [89. 26 （23.75-154. 34）] was higher than that in the group of normal WBC counts [ 3.86 （2. 03- 6.01 ） ] and the group of decreased WBC counts [ 6. 66 （2. 51-17.06） ] （Z = -4. 91, -4. 21, P 〈 0. 01 ）. The level of SALIA expression was positively correlated with blast cell counts in bone marrow and peripheral WBC counts （ r = 0.45,0.40, P 〈 0. 01 ）. Conclusions FQ-RT-PCR method can be used successfully to detect the expression of SAL/A,and the expression of SAL/A may be useful to predict disease progression of AML.