Up-regulation of miR-155 potentiates CD34+ CML stem/progenitor cells to escape from the growth-inhibitory effects of TGF-β1 and BMP signaling

Authors

  • Touba Mahdloo Department of Genetics, Faculty of Basic Sciences, Islamic Azad University, Marvdasht, Iran http://orcid.org/0000-0002-1535-1482
  • Pantea Sahami Department of Biomedical Sciences, Women Research Center, University of Alzahra, Tehran, Iran http://orcid.org/0000-0001-9223-7037
  • Reihaneh Ramezani Department of Biomedical Sciences, Women Research Center, University of Alzahra, Tehran, Iran http://orcid.org/0000-0002-7901-7627
  • Mojtaba Jafarinia Department of Genetics, Faculty of Basic Sciences, Islamic Azad University, Marvdasht, Iran http://orcid.org/0000-0003-4930-5190
  • Hamedreza Goudarzi Department of Genetics, Faculty of Basic Sciences, Islamic Azad University, Marvdasht, Iran http://orcid.org/0000-0002-3487-7041
  • Sadegh Babashah Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, P.O. Box: 14115-154, Tehran, Iran, Tel.: +98 21 8288 4468, fax: +98 21 8288 4717, E-mail: sadegh.babashah@gmail.com; babashah@modares.ac.ir http://orcid.org/0000-0001-7066-0918

DOI:

https://doi.org/10.17179/excli2021-3404

Keywords:

chronic myeloid leukemia, bone morphogenetic protein, TGF-β signaling, miR-155

Abstract

microRNAs (miRNAs or miRs) play key roles in different stages of chronic myeloid leukemia (CML) pathogenesis. The present study aimed to demonstrate whether miR-155 enables CD34+ CML cells to escape from the growth-inhibitory effects of TGF-β1 and bone morphogenetic protein (BMP) signaling. Among differentially expressed miRNAs in CD34+ CML cells, miR-155 was highly up-regulated. QRT-PCR revealed an inverse correlation between miR-155 and two key members of the TGF-β pathway—TGF-βR2 and SMAD5. Results showed that SMAD5 is not only up-regulated through BMPs treatment, but recombinant TGF-β1 can also induce SMAD5 in CML cells. We also demonstrated that TGF-β1-mediated phosphorylation of SMAD1/5 was abolished by pre-treatment with the blocking TGF-βR2 antibody, suggesting a possible involvement of TGF-βR2. Additionally, overexpression of miR-155 significantly promoted the proliferation rate of CD34+ CML cells. Results showed that siRNA-mediated knockdown of SMAD5 had a promoting effect on CD34+ CML cell proliferation, suggesting that SMAD5 knock-down recapitulates the proliferative effects of miR-155. Importantly, TGF-β1 and BMP2/4 treatment had inhibitory effects on cell proliferation; however, miR-155 overexpression enabled CD34+ CML cells to evade the anti-proliferative effects of TGF-β1 and BMPs. Consistently, down-regulation of miR-155 augmented the promoting effects of TGF-β1 and BMP signaling on inducing apoptosis in CD34+ CML stem cells. Our findings demonstrated that targeting of SMAD5 and TGF-βR2 links miR-155 to TGF-β signaling in CML. Overexpression of miR-155 enables CD34+ CML cells to evade growth-inhibitory effects of the TGF-β1 and BMP signaling, providing new perspectives for miR-155 as a therapeutic target for CML.

Published

2021-04-15

How to Cite

Mahdloo, T., Sahami, P., Ramezani, R. ., Jafarinia, M. ., Goudarzi, H., & Babashah, S. (2021). Up-regulation of miR-155 potentiates CD34+ CML stem/progenitor cells to escape from the growth-inhibitory effects of TGF-β1 and BMP signaling. EXCLI Journal, 20, 748–763. https://doi.org/10.17179/excli2021-3404

Issue

Section

Original articles