Document Type : Research articles


1 Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran

2 Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran

3 Faculty of Allied Medical Sciences, Kerman University of Medical Sciences, Kerman, Iran


Background: Several studies show that mesenchymal stem cells (MSCs) possess anti-tumor properties, while other studies show that MSCs may promote cancer. Extracellular vesicles (EVs) are identified as novel mediators to communicate among cells, which may be used as vehicles to transfer the MSC information to the target cells. Objectives: The current study aimed at investigating whether the human umbilical cord mesenchymal stem cell (HUSCMSC) de- rived extracellular vesicles (EVs) inhibits or promotes tumor cell growth in K562 chronic myelogenous leukemia cell line.
Methods: In the current experimental study, trypan blue exclusion and 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bro- mide (MTT) assay were performed to investigate the cell viability and metabolic activity. Additionally, flow cytometry was employed to assess cell cycle and apoptosis of K562 cells after 72 hours exposure to EVs. Results: The obtained results showed that no doses of EVs inhibited the tumor growth (mean ± standard deviation (SD) of cell viability at the day 10 was 94.4 ± 2.60, P > 0.05) and metabolic activity in three days (mean ± SD at the day 3 was 97.27 ± 2.46, P > 0.05). Furthermore, EVs also did not change the apoptosis rate (mean ± SD at the day 3 was 3.17 ± 2.34 for annexin positive cells, and 3.36 ± 1.91 for annexin/propidium iodide (PI) -positive cells, P > 0.05).
Conclusions: In conclusion, no significant changes in tumor cell growth were observed after treating K562 cells with MSCs-derived EVs.