[Correlation of Fms-like tyrosine kinase 3 (FLT3) gene expression to FLT3/internal tandem duplication mutation in peripheral blood of acute myeloid leukemia.].
OBJECTIVE
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.


METHODS
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.


RESULTS
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%).


CONCLUSIONS
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.
Xu
Bing
B
Department of Hematology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, P.R. China. xbzj@fimmu.com
Shi
Peng-Chang
PC
Song
Xiao-Yan
XY
Tang
Jia-Hong
JH
Zhou
Shu-Yun
SY
D000293:Adolescent; D000328:Adult; D001854:Bone Marrow Cells / Q000166:cytology; D002452:Cell Count; D004909:Erythrocyte Indices; D005260:Female; D020440:Gene Duplication; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010976:Platelet Count; D012074:Remission Induction; D020080:Tandem Repeat Sequences; D055815:Young Adult; D051941:fms-Like Tyrosine Kinase 3 / Q000097:blood / Q000235:genetics* / Q000378:metabolism
C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3