High expression of Midkine (MK) indicates poor prognosis in childhood acute lymphoblastic leukemia.
OBJECTIVE
Midkine (MK) expression has been reported to be correlated with the poor prognosis of patients with various tumors. However, there are no data available about the prognostic value of MK expression in childhood acute lymphoblastic leukemia (ALL).


METHODS
In this study, MK mRNA expression was determined by real-time polymerase chain reaction in 120 childhood ALL and 30 healthy volunteers. Patients were dichotomized at the median value and divided into two groups: MK(low) group and MK(high) group.


RESULTS
MK(high) patients had higher white blood cell counts, higher peripheral blood blasts percentages, and higher minimal residual disease levels than MK(low) patients. Moreover, the MK gene was expressed significantly higher in patients with relapsed ALL than in patients who maintained complete remission or at diagnosis. MK(high) patients harbored inferior relapse-free survival (RFS, P = 0.047) and overall survival (OS, P = 0.022) than MK(low) patients, and high expression of MK was found to be independently predictive of inferior OS (P = 0.032) but not RFS (P = 0.077) in the overall cohort.


CONCLUSIONS
MK high expression is an independent adverse prognostic factor in childhood ALL. Its level may be incorporated into an improved risk classification system for ALL and suggest the need of alternative regimens.
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Ming
M
Jia
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Hai-Zhao
HZ
Zhao
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Yu-Ping
YP
Cheng
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Ze-Bin
ZB
Luo
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Jing-Ying
JY
Zhang
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Si-Si
SS
Li
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Xiao-Jun
XJ
Xu
a Division of Hematology-Oncology , Children's Hospital of Zhejiang University School of Medicine, Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education , Hangzhou 310003 , PR China.
Yong-Min
YM
Tang
D000293:Adolescent; D001752:Blast Crisis / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007223:Infant; D007958:Leukocyte Count; D008297:Male; D000078792:Midkine; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D015996:Survival Rate
C066254:MDK protein, human; D009363:Neoplasm Proteins; D009414:Nerve Growth Factors; D000078792:Midkine
Acute lymphoblastic leukemia; Childhood; Midkine; Prognosis