Mesenchymal stem cells inhibited chronic myeloid leukemia cells in vitro, correlating with oxidative stress
摘要
Chronic myeloid leukemia (CML) originates from bone marrow, and its progression to blast crisis phase is a primary cause of poor prognosis in patients. Investigating its underlying mechanisms may help improve patient survival.
MethodsOptical microscopy and Cell Counting Kit-8 assays were utilized to observe and assess the viability of K562 cells (human cells derived from CML) treated with or without mesenchymal stem cell (MSC)-conditioned medium. Flow cytometry was employed to assess apoptosis and cell cycle changes. Intracellular reactive oxygen species (ROS) were assessed utilizing a 2’,7’-dichlorofluorescin diacetate probe. Antioxidant enzymes (total superoxide dismutase [T-SOD], catalase [CAT], glutathione peroxidase [GSH-Px]) and malondialdehyde (MDA), a marker of lipid peroxidation and oxidative stress, were measured using relevant assay kits. Western blotting was performed to evaluate inflammation-related proteins (nuclear factor erythroid 2-related factor 2 [Nrf2], inhibitor of nuclear factor kappa B alpha [IκBα]), and reverse transcription quantitative polymerase chain reaction (RT-qPCR) was utilized to assess expression of inflammatory cytokines (interleukin [IL]-6, IL-1β, IL-4, IL-10). All experiments were repeated three times, and the data were presented in mean form. Welch t-test was used to compare the treatment group and the control group.
ResultsCompared with K562 cells without MSC-conditioned medium treatment, those cultured with MSC-conditioned medium exhibited significantly inhibited proliferation. The K562 cells treated with MSC-conditioned medium showed increased apoptosis compared with untreated cells (11.34% vs. 2.93%, P<0.0001) and cell cycle arrest (17.54% vs. 11.00%, P = 0.0007). Additionally, the K562 cell group with MSC-conditioned medium treatment elevated intracellular ROS levels (9.34% vs. 2.43%, P = 0.0002) in K562 cells. Oxidative stress factor analysis revealed decreased T-SOD (3.82 vs. 6.89, P = 0.0023), CAT (21.43 vs. 34.36, P = 0.0025), and GSH-Px (3.42 vs. 6.88, P = 0.0088) levels alongside increased MDA (6.29 vs. 3.30, P = 0.0009) in K562 cell group with MSC-conditioned medium treatment. Inflammatory protein assessment demonstrated reduced Nrf2 (0.46 vs. 1.00, P = 0.0017) and IκBα (0.71 vs. 1.00, P = 0.0002) levels in the K562 cell group with MSC-conditioned medium treatment. IL-6 (2.14 vs. 1.00, P<0.0001) and IL-1β (2.21 vs. 1.00, P<0.0001) were upregulated, whereas IL-4 (0.52 vs. 1.00, P<0.0001) and IL-10 (0.39 vs. 1.00, P<0.0001) were downregulated.
ConclusionMSC-conditioned medium inhibited K562 cell growth concomitant with increased oxidative stress and altered inflammatory responses.