Promotive effect of C/EBPepsilon overexpression on differentiation of human myelomonocytic leukemia cell line U-937.
OBJECTIVE
CCAAT-enhancer binding protein omega (C/EBPepsilon) is a kind of nuclear transcriptional factor expressed predominantly in myeloid cells, and may be a critical regulator of myeloid differentiation, which can activate the transcription of a subset of myeloid-specific genes. This study was to detect the cell-specific expression of C/EBPepsilon, and to investigate the effect of C/EBPepsilon overexpression on c-Myc expression, cell cycle distribution, and cell differentiation of human myelomonocytic leukemia cell line U-937.


METHODS
The expression of C/EBPepsilon in 5 hematopoietic cell lines (U-937, NB4, HL-60, K-562 and Jurkat T cell lines) was tested by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). According to the RT-PCR results, human myelomonocytic leukemia cell line U-937 was selected and transfected with pcDNA3.1-C/EBPepsilon32 expression vector by electroperforation, and screened by G418 to yield positive clones which were termed U-937-C/EBPepsilon32. The expression of C/EBPepsilon and c-Myc in U937-C/EBPepsilon32 cells was detected by RT-PCR and Western blot; cell cycle and differentiation of U937-C/EBPepsilon32 cells was analyzed by flow cytometry.


RESULTS
C/EBPepsilon overexpression obviously increased the expression of CD11b (a cell surface marker of granulocyte maturity). The positive rate of CD11b was significantly higher in U-937-C/EBPepsilon32 cells than in U-937 and U-937-pcDNA3.1 cells(92.56% vs. 77.46% and 74.81%), while c-Myc expression and cell cycle had no changes.


CONCLUSIONS
C/EBPepsilon might be an essential transcriptional regulator for U-937 cells differentiating into granulocytes.
Cai
Rong
R
Department of Biochemistry and Molecular Biology, School of Medicine, Shanghai Jiaotong University, Shanghai, 200025, P. R. China.
Dai
Bing-Bing
BB
Li
Ke
K
Wang
Hong-Jie
HJ
Xu
Wei-Rong
WR
Wang
Jia-Min
JM
Lu
Jian
J
D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D039481:CD11b Antigen / Q000378:metabolism; D002453:Cell Cycle; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D018274:Electroporation; D005434:Flow Cytometry; D006801:Humans; D010957:Plasmids; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D020298:U937 Cells / Q000166:cytology / Q000378:metabolism
D022762:CCAAT-Enhancer-Binding Proteins; D039481:CD11b Antigen; C509295:ITGAM protein, human; D016271:Proto-Oncogene Proteins c-myc; C070790:CEBPE protein, human