Xu Bing, Shi Peng-Chang, Song Xiao-Yan, Tang Jia-Hong, Zhou Shu-Yun
Department of Hematology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, P.R. China.
Ai Zheng. 2009 Jun;28(6):632-6.
Fms-like tyrosine kinase 3 internal tandem duplication (FLT3/ITD) is associated with an unfavorable prognosis in acute myeloid leukemia (AML). However, the role of FLT3 expression as well as its correlation to FLT3/ITD has not sufficiently studied. This study was to evaluate the relationship between FLT3 gene expression and FLT3/ITD mutation in patients with de novo AML.
FLT3 gene expression was determined by real-time quantitative polymerase chain reaction (RQ-PCR). FLT3/ITD mutation was detected by PCR in 79 de novo AML patients.
FLT3/ITD mutations were found in 22.8% (18/79) patients. FLT3 gene expression (range: 0-7320, median: 312) was detected in 92.4% (73/79) patients, but not in normal controls. Compared to AML patients with low FLT3 expressers and without FLT3/ITD mutation, patients with high FLT3 expressers and FLT3/ITD mutation had a significantly higher white blood count as well as a higher ratio of bone marrow blasts. The positive rate of FLT3/ITD mutation was not correlated to the level of FLT3 expression, and no statistical difference of FLT3 expression was found between AML patients with and without FLT3/ITD mutation. The complete remission (CR) rate of AML patients with FLT3/ITD mutation (58.8%) was significance lower than that of those without FLT3/ITD mutation (82.1%). In AML patients without FLT3/ITD mutation, the CR rate was significantly lower in patients with high FLT3 expressers (69.2%) than in those with low FLT3 expressers (93.3%).
The FLT3 expression is not associated with FLT3/ITD mutation. High-FLT3 expression may be a poor prognostic factor for AML patients without FLT3/ITD mutation.
Fms样酪氨酸激酶3内部串联重复（FLT3/ITD）与急性髓系白血病（AML）的不良预后相关。然而，FLT3表达的作用及其与FLT3/ITD的相关性尚未得到充分研究。本研究旨在评估初发AML患者中FLT3基因表达与FLT3/ITD突变之间的关系。
采用实时定量聚合酶链反应（RQ-PCR）测定FLT3基因表达。通过PCR检测79例初发AML患者的FLT3/ITD突变。
22.8%（18/79）的患者检测到FLT3/ITD突变。92.4%（73/79）的患者检测到FLT3基因表达（范围：0 - 7320，中位数：312），而正常对照未检测到。与FLT3低表达且无FLT3/ITD突变的AML患者相比，FLT3高表达且有FLT3/ITD突变的患者白细胞计数显著更高，骨髓原始细胞比例也更高。FLT3/ITD突变的阳性率与FLT3表达水平无关，有FLT3/ITD突变和无FLT3/ITD突变的AML患者之间FLT3表达无统计学差异。FLT3/ITD突变的AML患者完全缓解（CR）率（58.8%）显著低于无FLT3/ITD突变的患者（82.1%）。在无FLT3/ITD突变的AML患者中，FLT3高表达患者的CR率（69.2%）显著低于FLT3低表达患者（93.3%）。
FLT3表达与FLT3/ITD突变无关。高FLT3表达可能是无FLT3/ITD突变的AML患者的不良预后因素。
