RESUMO
Mesenchymal stem cells (MSCs) are promising for clinical studies owing to their self-renewal, multipotency, trophic, and immunomodulatory properties. This study aimed to investigate the cytokine levels of human umbilical cord blood (CB) and Wharton's Jelly-(WJ) derived MSCs relevant to immune modulation on different passage levels in vitro. Umbilical CB MSCs were isolated using the ficoll-paque gradient method, and WJ-MSCs were isolated by the explant method. After isolation, the MSCs were characterized using flow cytometry. The supernatant cytokine levels (interferon-gamma (IFN-γ), interleukin 4 (IL-4), interleukin 17 (IL-17)) of MSCs at each passage were evaluated using the ELISA assay. MSCs exhibited different cytokine levels with each passage number. In WJ-MSC culture supernatants, IL-17 levels significantly increased at P4 and P5 compared to the first passage (p < 0.005), while the other passages showed a decrease. IFN-γ levels increased at passage P1 and P4 and decreased at other passages (p < 0.005). IL-4 levels significantly increased only at passage P3 (p < 0.005). In CB-MSC culture supernatants, IL-17 and IL-4 cytokines decreased compared to P0, while IFN-γ cytokine increased from P0 (p < 0.005). The changing ratio of cytokine levelsfor both CB-MSCs and WJ-MSCs were similarly maintained from early to late passages. More research is needed to understand the immunomodulatory functions of MSCs.
RESUMO
BACKGROUND: Mesenchymal stem cells (MSCs) have the ability to self-renew and are multi-potent. They are a primary candidate for cell-based therapy due to their potential anti-cancer effects. The aim of this study was to evaluate the in vitro anti-leukemic effect of Wharton's Jelly-derived MSC (WJ-MSC) on the leukemic cell lines K562 and HL-60. METHODS: In this present study, WJ-MSCs were isolated from human umbilical cord. The cells were incubated according to the standard culture conditions and characterized by flow cytometry. For experiments, WJ-MSC and leukemic cells were incubated in the direct co-culture at a ratio of 1:5 (leukemia cells: WJ-MSC). HUVEC cells were used as a non-cancerous cell line model. The apoptotic effect of WJ-MSCs on the cell lines was analyzed using Annexin V/PI apoptosis assay. RESULTS: After the direct co-culture of WJ-MSCs on leukemic cell lines, we observed anti-leukemic effects by inducing apoptosis. We had two groups of determination apoptosis with and without WJ-MSCs for all cell lines. Increased apoptosis rates were observed in K562 and HL-60 cell lines, whereas the apoptosis rates in HUVEC cells were low. CONCLUSIONS: MSCs are known to inhibit the growth of tumors of both hematopoietic and non-hematopoietic origin in vitro. In our study, WJ-MSC treatment strongly inhibited the viability of HL-60 and K562 and induced apoptosis. Our results also provided new insights into the inhibition of tumor growth by WJ-MSCs in vitro. In the future, WJ-MSCs could be used to inhibit cancer cells in clinical applications.