[Effect and possible mechanism of HnRNP E2 decoy RNA on proliferation of K562 leukemia cells].
OBJECTIVE
The abnormal expression of poly(rC)-binding protein E2 (hnRNP E2) induced by BCR/ABL plays an important role in blast crisis of chronic myeloid leukemia (CML). The present study was to investigate the effect of hnRNP E2 decoy RNA on the cell proliferation in K562 leukemia cells, and further elucidate the possible underlying mechanisms.


METHODS
Decoy hnRNP E2 plasmid was constructed and transfected into K562 cells using cationic liposome. Stably transfected cells were selected with G418. The cell proliferation rate was determined by cell growth curve using trypan blue staining, and the cell cycle was analyzed by flow cytometry. The changes of CCAAT/enhancer-binding protein alpha (C/EBP alpha) and c-Myc gene expression were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot.


RESULTS
The proliferation rate of stably transfected K562 cells was inhibited by (62.73+/-12.92)%. The cell cycle was arrested at S phase [stably transfected K562 cell group: (55.59+/-4.67)%, control group: (44.70+/-4.21)%, P<0.05]; C/EBPalpha mRNA level remained unchanged. However the 42 ku-C/EBPalpha protein expression was elevated by (49.72+/-5.58)%; c-Myc mRNA and protein expression was inhibited by (58.27+/-7.23)% and (57.26+/-6.52)%, respectively.


CONCLUSIONS
HnRNP E2 decoy RNA could inhibit the proliferation of K562 cells, and this may be caused by the blockage of the binding between hnRNP E2 and C/EBPalpha mRNA and subsequent elevation of 42 ku-C/EBPalpha by decoy RNA.
Chen
Xin-Min
XM
Department of Clinical Hematology, Key Laboratory of Laboratory Medical Diagnostics of Education Ministry, Chongqing University of Medical Sciences, Chongqing, 400016, P. R. China.
Feng
Wen-Li
WL
Zhao
Shi-Qiao
SQ
Zeng
Jian-Ming
JM
Bai
Wei-Jun
WJ
Wang
Xiao-Zhong
XZ
Huang
Zong-Gan
ZG
D001483:Base Sequence; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000096:biosynthesis* / Q000235:genetics; D002453:Cell Cycle; D049109:Cell Proliferation; D006801:Humans; D020014:K562 Cells; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D012313:RNA / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D022763:CCAAT-Enhancer-Binding Protein-alpha; C501903:PCBP2 protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012313:RNA