ABSTRACT
AIM:To explore the regulatory effect of microRNA-3666 (miR-3666) on the expression of its tar-get gene phosphatase and tensin homologue deleted on chromosome ten (PTEN) in leukemic cells.METHODS: miR-3666 expression levels in normal peripheral blood mononuclear cells and leukemic cells were determined by quantitative real-time PCR.miR-3666 targeting PTEN 3'-untranslated region (3'UTR) was predicted by TargetScan software .3'UTR of PTEN was inserted in the dual luciferase reporter vector psiCHECK 2.The reporter activity was evaluated by the Dual-Lu-ciferase Reporter Assay System after the luciferase promoter vector and miRNA were co -transfected into HEK293T cell line. K562 cells were transfected with synthetic miR-3666 inhibitor ( anti-miR-3666) or a synthetic control miRNA ( anti-miR-C) .The expression of PTEN protein in the above transfected K 562 cells was determined by Western blotting .RESULTS:miR-3666 was up-regulated in the human leukemic cell lines and primary leukemic cells compared to normal peripheral blood mononuclear cells .The results of dual luciferase assays validated PTEN as a specific target gene of miR-3666.Inhi-bition of miR-3666 resulted in an up-regulation of PTEN protein expression in the K 562 cells.CONCLUSION:miR-3666 is over-expressed in leukemic cells .The abnormal over-expression of miR-3666 may play a key role in leukemia due to the down-regulation of PTEN .