Acute Myeloid Leukemia is a cancer of leukemic stem cells (LSCs) with a rapid progression. It is characterized by overproduction of immature myeloid cells in bone marrow which crowds out normal hematopoietic stem cells (HSC). TIM-3, an immune regulatory molecule, is an LSC specific surface marker in AML with high expression on these cells compared to HSCs. Studies have indicated that micro RNAs (miRNAs) may play an important role in either cancer progression or suppression. Based on bioinformatics assessments, we have predicted that miR-125a-3p could be a miRNA with high suppressive activity on TIM-3 expression. The purpose of this study was to investigate the inhibitory effect of miR-125a-3p on TIM-3 gene expression in an AML cell line, HL-60, in vitro. HL-60 cells were cultured in RPMI 1640 supplied with 10 % FBS. TIM-3 expression was induced on the cells using phorbol miristate acetate. The cells were transfected with miR-125-3p for 24 h and the gene and protein expression of TIM-3 were measured using q-RT-PCR and flow-cytometery methods, respectively. The results of this study showed that miR-125a-3p has a strong silencing effect on TIM-3 gene and protein expression on HL-60 cell line. Based to our results, miR125a-3p can strongly silence TIM-3 expression in AML cell line. Thus, our results have confirmed the bioinformatics prediction of suppressive effect of miR-125a-3p on TIM-3with Mirwalk and Target Scan softwares.
Keywords: AML; TIM-3; miR-125a-3p.