Silencing of TIM-3 expression by miR-326 affects apoptosis and proliferation of human HL-60 leukemia cell line


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Mohammad-Ganji M., Ganjalikhani-Hakemi M., Homayouni V., Rezaei A., Khanahmad H.

UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi, vol.28, no.2, pp.112-122, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 2
  • Publication Date: 2018
  • Doi Number: 10.4999/uhod.182354
  • Journal Name: UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.112-122
  • Keywords: Acute myeloid leukemia, Apoptosis, Microrna-326, Proliferation, T cell immunoglobulin mucin-3
  • Istanbul Medipol University Affiliated: No

Abstract

Leukemia Stem Cells (LSCs) are the main reason for drug-resistance and disease relapse in Acute Myeloid Leukemia (AML). Current drugs destroy normal Hematopoietic Stem Cells (HSCs) rather than LSCs. T cell immunoglobulin mucin-3 (TIM-3), an immune regulatory molecule, is a CD34+CD38- LSCs specific surface marker with high expression on these cells compared to HSCs. The interaction between TIM-3 and its ligand, Galectin-9 (Gal-9), mediates signaling pathways involved in apoptosis and proliferation. We hypothesized that miR-326 could have a suppressive activity on TIM-3 expression and hence, affects the proliferation and apoptosis processes in AML cells. Bioinformatics predictions were done using Mirwalk and Target Scan softwares. TIM-3 expression was induced on HL-60 cells by PMA. After miR-326 transfection, MTT, q-RT-PCR, flow- cytometery were performed to evaluate the cells survival and TIM-3 expression level. Then, after adding recombinant Galectin-9, apoptosis and proliferation rates were measured with Annexin-V and CFSE assays, respectively. Flow cytometry assay confirmed our bioinformatics prediction of suppressive effect of miR- 326 on TIM-3 expression (66.4% silencing) in HL-60 cell line (p= 0.002). The qRT-PCR results were also confirmatory. Annexin-V and MTT assays showed increased cell apoptosis and decreased cell survival, while data from CFSE assay indicated a severe reduction in HL-60 cells proliferation. Our results demonstrated that, miR-326 can silence TIM-3 expression in AML HL-60 cells. Moreover, it is shown that miR-326 can enhance AML cells apoptosis and reduce their proliferation and survival and hence, might be considered as a novel target for therapeutic approaches against AML.