成人急性淋巴细胞白血病骨髓中miR-34a的表达及其在细胞耐药中的意义

Expression of miR-34a in Bone Marrow of Adult Acute Lymphoblastic Leukemia and Its Significance in Cell Drug Resistance

目的:探讨miR-34a在成人急性淋巴细胞白血病(ALL)骨髓中的表达及其与耐药性的关系。方法:47例初诊ALL患者,分别于初诊和复发或完全缓解时留取骨髓样品,初诊-完全缓解组标本26对,初诊-复发组标本21对。利用实时荧光定量PCR对患者骨髓样品、人CCRF-CEM细胞株及其耐药株CEM-C1细胞中miR-34a表达水平进行检测。利用电穿孔转染法抑制CCRF-CEM细胞并上调CEM-C1细胞中miR-34a表达,分别用不同浓度喜树碱进行培养,利用CCK-8法对细胞存活情况进行分析,计算细胞增殖抑制率(%)和耐药指数(RI)。结果:初诊-完全缓解组中,初诊时患者骨髓样品中miR-34a表达水平显著低于完全缓解时和对照组,差异具有统计学意义(P<0.05),初诊-复发组中,初诊时和复发时患者骨髓样品中miR-34a相对表达量均低于对照组,差异均有统计学意义(P<0.05);miR-34a在CEM-C1细胞中表达水平为(2.64±1.37),显著低于CCRF-CEM细胞中的(5.14±2.06)(P<0.05);转染miR-34a抑制物的CCRF-CEM细胞中miR-34a表达水平为(3.14±1.15),显著低于miRNA抑制剂阴性对照CCRF-CEM细胞(P<0.05),转染miR-34a抑制物的CCRF-CEM细胞增殖抑制率显著高于转染阴性对照细胞(P<0.05),IC_(50)分别为28.73和2167.00 ng/ml,RI=75.43;转染miR-34a模拟物的CEM-C1细胞中miR-34a表达水平(5.06±1.73),显著高于miRNA模拟物阴性对照CEM-C1细胞(P<0.05),转染miR-34a模拟物的CCRF-C1细胞增殖抑制率显著低于转染阴性对照细胞(P<0.05),IC_(50)分别为112.57 ng/m L和1.27 ng/m L,RI=88.64。结论:miR-34a在成人ALL骨髓样品中呈低表达,可能与ALL复发及耐药性的发生有关。

Objective:To investigate the expressions of miR-34 a in bone marrow of adult acute lymphoblastic leukemia（ALL） and its relationship with drug resistance.Methods:Forty- seven cases of newly diagnosed adult ALL were selected and their bone marrow samples were taken at the time of newly diagnosed and relapsed or complete remission;26 pairs of specimens were in newly diagnosed-complete remission group,and 21 pairs of specimens were in newly diagnosed-relapse group.The expressions of miR-34 a in bone marrow samples,CCRF-CEM cells and resistant CEM-C1 cell strains were detected by real-time quantitative PCR.The expression of miR-34 a in CCRF-CEM cells was inhibited and was increased in CEM-C1 cells detected by electroporation transfection method.All the cells were incubated at different concentration of camptothecin.The cell survival was analyzed by CCK-8 method,the cell proliferation inhibition rate（%） and resistance index（RI） were calculated.Results:In newly diagnosed- complete remission group,the miR-34 a expression at newly diagnosis was significantly lower than that in complete remission and the control group,the differences were statistically significant（P < 0.05）.In newly diagnosed- relapsed group,the miR-34 a expressions at newly diagnosis and relapse were lower than those in the control group,the differences were statistically significant（P <0.05）.The expression level in CEM-C1 cells was（2.64 ± 1.37） which significantly lower than that in CCRF-CEM cells（5.14 ±2.06）,the differences were statistically significant（P < 0.05）.The expression level of miR-34 a in CCRF-CEM cells transfected with miR-34 a inhibitor was（3.14 ± 1.15）,which significantly lower than that in the miRNA inhibitor- negative control group,the difference was statistically significant（P < 0.05）.The cell proliferation inhibition rate of CCRF-CEM cells transfected with miR-34 a inhibitor was significantly higher than that in the negative control transfectedcells（P < 0.05）,the IC50 was 28.73 ng /mL and 2167.00 ng /mL respectively,and RI= 75.43.The expression level of miR-34 a in CEM-C1 cells transfected with miR-34 a mimic was（5.06 ± 1.73）,which was significantly higher than that in the miRNA mimics transteted- negative control CEM-C1 cells（P < 0.05）.The proliferation inhibition rate in CEM-C1 cells transfected with miR-34 a mimic was significantly lower than that in the negative control- transfected cells（P <0.05）.The IC50 was 112.57 ng/mL and 1.27 ng/mL respectively,and the RI= 88.64.Conclusion:The expression of miR-34 a in bone marrow samples of adult ALL is low which may be associated with the relapse and drug resistance of ALL.