Hsa-mir-181a Post-transcriptionally Down-regulates Oncogenic PPFIA1and Affects Proliferation,apotosis And STI571-sensitivity In Chronic Myelogenous Leukemia(cml) Cells

Objective：Our goal is to identify target gene PPFIA1of hsa-miR-181a and investigate its potentialroles in leukemia K562cells. This study will be also expected to provide newexperimental evidence for miRNA therapeutics in leukemia.Methods:1) Transfecting hsa-miR-181a mimics and its candidate target genes PPFIA1siRNAinto K562by LipofectamineTM2000, PPFIA1expression level was detected byReal-time PCR and Western blot at48hours post-transfection.2) Construction of PPFIA1-3’UTR Dual Luciferase Reporter, the vector and mir-181awere co-transfected into293T cells for analysis of Luciferase value.3) The effect of hsa-miR-181a and PPFIA1siRNA on K562cells growth weredetermined by MTT and trypan blue exclusion assay.4) Cells apoptosis were analysed by cytometry using double stainingwith AnnexinV-PI.5) The effect of hsa-miR-181a, and PPFIA1siRNA on STI571sensitivity in K562cellswere determined by MTT.Results:1) hsa-miR-181a, like PPFIA1siRNA, significantly downregulated the mRNA andprotein expression level of PPFIA1at48hours post-transfection.2) hsa-miR-181a significantly decreased the luciferase activity of PPFIA1-3’UTRreporter without affecting the activity of PPFIA1-mut-3’UTR reporter.3) Both hsa-miR-181a and PPFIA1siRNA effectively suppressed cell growth, showinga dose-dependent effect and lasting for more than72h.4) Both hsa-miR-181a and PPFIA1siRNA promoted cell apotosis effectively. and enhanced sensitivity of K562cell to STI571.Conclusion:1) PPFIA1is one of the direct target genes of hsa-miR-181a in K562cell.2) hsa-miR-181a effectively inhibits cell growth, induces cell apoptosis and increaseSTI571-sensitivity at least partially by post-transcriptionally targeting PPFIA1inK562cells.