The effect of hnRNP E2 decoy RNA on proliferation of 32D-BCR/ABL cells.

Objective:Expression of poly(rC)-binding protein E2(hnRNP E2) was abnormal from chronic phase to blast crisis of chronic myeloid leukemia(CML).The present study was to investigate the effect of hnRNP E2 decoy RNA on the proliferation of 32D-BCR/ABL cells and the possible molecular mechanisms.Methods:Plasmids expressing wild sequence(pGD) and mutation sequence(pGM) of hnRNP E2 decoy RNA were transfected into 32D-BCR/ABL cells with electroporation method.Stably transfected cells were selected with G418.The cell reproductive activity was detected by cell growth curve using trypan blue staining and colony formation test;the cell cycle was analyzed by flow cytometry;the mRNA and protein expressions of downstream CCAAT/enhancer-binding protein α(C/EBPα) and c-Myc were determined by RT-PCR and Western blot.Results:The stably expressed 32DP210-pGD cells and 32DP210-pGM cells were selected.The proliferation of 32DP210-pGD cells was inhibited compared with untreated 32D-BCR/ABL cells.The inhibitory rate was(69.48±5.21)%.The clony formation ability of 32DP210-pGD cells was weakened.The 32DP210-pGD cells were arrested at G0/G1 phase.The expression of C/EBPα mRNA of 32DP210-pGD cells remained unchanged,but the 42 ku-C/EBPα protein expression was elevated by(43.83±4.91)%;mRNA and protein expression levels of c-Myc were decreased by(35.67±6.64)% and(30.91±3.84)%,respectively.However,there was no significant difference between 32DP210-pGM cells and untreated 32D-BCR/ABL cells in the above mentioned parameters.Conclusion:hnRNP E2 decoy RNA inhibited the proliferation of 32D-BCR/ABL cell.The action mechanism of hnRNP E2 decoy RNA may be related with its effect of blocking the binding of hnRNP E2 with C/EBPα mRNA and subsequent elevation of 42 ku-C/EBPα and down-regulation of c-Myc gene expression.