目的　通过检测miR-196b在初诊急性髓系白血病(AML)患儿中的表达，评估miR-196b在儿童AML中的临床意义。方法　从标本库中抽取52例初诊AML患儿骨髓，利用qRT-PCR方法检测miR-196b表达水平(结果以2-ΔΔCt表示)，并与同期30例非白血病患儿标本对照。结果　单核系组(M4、M5)的miR-196b表达水平高于非单核系组(M1、M2、M3、M6、M7)和对照组，而非单核系组低于对照组，差异均有统计学意义(P<0.01)。miR-196b表达水平在t(15；17)组最低，11q23(MLL)组最高，差异有统计学意义(P<0.01)。使用NCCN2013预后分组标准，预后良好组miR-196b表达低于预后不良组，差异有统计学意义(P<0.01)。首疗程缓解组miR-196b表达明显低于首疗程未缓解组，差异有统计学意义(P<0.05)。WBC≥100×109/L组miR-196b表达水平高于WBC<100×109/L组，差异有统计学意义(P<0.01)。miR-196b表达水平与初诊时血小板计数呈显著正相关(r=0.302，P=0.030)。结论　miR-196b表达水平在初诊AML预后不良组明显增高，高水平的miR-196b与低缓解率和较差的预后相关。miR-196b有望成为AML患儿治疗新靶点。

Objective　To evaluate the expression of miR-196b in newly diagnosed pediatric acute myeloid leukemia (AML) and its clinical significance. Methods Fifty-two AML children were enrolled in this study and 30 non-leukemia compared children were selected as controls. The expressions of miR-196b were detected in bone marrow samples by real-time quantitative PCR (q-RT-PCR) and the results were expressed in 2-ΔΔCt. Results miR-196b expressions were significantly higher in M4-5 and lower in non- M4-5 of AML children than those in control (P<0.01), with a lowest level in t (15;17) and a highest level in MLL subtypes (P<0.01). The miR-196b expressions were significantly different among different prognosis groups (P<0.01) and the level in the favorable prognostic group was lower than in poor prognosis group. It was also found that miR-196b expression was lower in remission group than that in no-remission group after the first induction remission therapy (P<0.05). Meanwhile, the expression of miR-196b in the children with WBC≥100×109/L were statistically higher than that in the children with WBC<100×109/L (P<0.01), and miR-196b level was positively correlated with the platelet counts (r=0.302, P=0.030). Conclusions miR-196b expression is increased in poor prognosis group of AML children, and high expression of miR-196b is related with low response rate and poor prognosis. miR-1966 is expected to become a new target for the treatment of AML.