Hypermethylation of the GATA binding protein 4 (GATA4) promoter in Chinese pediatric acute myeloid leukemia.
BACKGROUND
Acute myeloid leukemia (AML) is the second-most common form of leukemia in children. Aberrant DNA methylation patterns are a characteristic feature of AML. GATA4 has been suggested to be a tumor suppressor gene regulated by promoter hypermethylation in various types of human cancers although the expression and promoter methylation of GATA4 in pediatric AML is still unclear.


METHODS
Transcriptional expression levels of GATA4 were evaluated by semi-quantitative and real-time PCR. Methylation status was investigated by methylation-specific PCR (MSP) and bisulfate genomic sequencing (BGS). The prognostic significance of GATA4 expression and promoter methylation was assessed in 105 cases of Chinese pediatric acute myeloid leukemia patients with clinical follow-up records.


RESULTS
MSP and BGS analysis showed that the GATA4 gene promoter is hypermethylated in AML cells, such as the HL-60 and MV4-11 human myeloid leukemia cell lines. 5-Aza treatment significantly upregulated GATA4 expression in HL-60 and MV4-11 cells. Aberrant methylation of GATA4 was observed in 15.0 % (3/20) of the normal bone marrow control samples compared to 56.2 % (59/105) of the pediatric AML samples. GATA4 transcript levels were significantly decreased in AML patients (33.06 ± 70.94; P = 0.011) compared to normal bone marrow/idiopathic thrombocytopenic purpura controls (116.76 ± 105.39). GATA4 promoter methylation was correlated with patient leukocyte counts (WBC, white blood cells) (P = 0.035) and minimal residual disease MRD (P = 0.031). Kaplan-Meier survival analysis revealed significantly shorter overall survival time in patients with GATA4 promoter methylation (P = 0.014).


CONCLUSIONS
Epigenetic inactivation of GATA4 by promoter hypermethylation was observed in both AML cell lines and pediatric AML samples; our study implicates GATA4 as a putative tumor suppressor gene in pediatric AML. In addition, our findings imply that GATA4 promoter methylation is correlated with WBC and MRD. Kaplan-Meier survival analysis revealed significantly shorter overall survival in pediatric AML with GATA4 promoter methylation but multivariate analysis shows that it is not an independent factor. However, further research focusing on the mechanism of GATA4 in pediatric leukemia is required.
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. taoyanfang1982@163.com.
Yan-Fang
YF
Tao
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. baseff77@hotmail.com.
Fang
F
Fang
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. hsy139@126.com.
Shao-Yan
SY
Hu
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. drlujun_sz@163.com.
Jun
J
Lu
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. cl2012@sohu.com.
Lan
L
Cao
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. wenlizhao69@163.com.
Wen-Li
WL
Zhao
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. xiaopfdr@gmail.com.
Pei-Fang
PF
Xiao
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. szlizhiheng@hotmail.com.
Zhi-Heng
ZH
Li
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. 570843000@qq.com.
Na-Na
NN
Wang
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. xulixiao2013@hotmail.com.
Li-Xiao
LX
Xu
Department of Gastroenterology, the 5th Hospital of Chinese PLA, Yin chuan, China. du_xiaojuan123@163.com.
Xiao-Juan
XJ
Du
Department of Cell and Molecular Biology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China. sunlichao_1980@hotmail.com.
Li-Chao
LC
Sun
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. lyh072006@hotmail.com.
Yan-Hong
YH
Li
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. ray8302880@163.com.
Yi-Ping
YP
Li
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. rdxyy@163.com.
Yun-Yun
YY
Xu
Translational Research Center, Second Hospital, The Second Clinical School, Nanjing Medical University, Nanjing, China. ni_jian2008@163.com.
Jian
J
Ni
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. wj196312@vip.163.com.
Jian
J
Wang
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. xing_feng66@hotmail.com.
Xing
X
Feng
Department of Hematology and Oncology, Childrens Hospital of Soochow University, Suzhou, China. panjian2008@163.com.
Jian
J
Pan
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D050991:GATA4 Transcription Factor / Q000096:biosynthesis / Q000235:genetics*; D015973:Gene Expression Regulation, Leukemic; D018922:HL-60 Cells; D006801:Humans; D053208:Kaplan-Meier Estimate; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000473:pathology; D008297:Male; D011379:Prognosis; D011401:Promoter Regions, Genetic
D050991:GATA4 Transcription Factor; C484170:GATA4 protein, human