Abstract: Objective To investigate the effects of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on the
proliferation and survival of Jurkat leukemia cells in vitro and explore the possible mechanism. Methods Jurkat leukemia cells
were co-cultured with hUC-MSCs isolated from human umbilical cord tissues by plastic adherence at a ratio of 10∶1. The
proliferation and survival of the co-cultured Jurkat cells, separated by immunomagnetic bead cell sorting on day 4, were
evaluated by flow cytometry. Western blotting was performed to evaluate the activation of Notch signaling in the co-cultured
Jurkat cells. Results Jurkat leukemia cells co-cultured with hUC-MSCs for 4 days showed a lowered proliferation rate and cell
cycle arrest at G0/G1 phase with a reduction in the cell apoptotic rate. Notch signaling pathway was activated in the co-cultured
Jurkat cells as evidenced by an increased cellular expression of HES-1. Conclusion Co-culture with hUC-MSCs can inhibit the
proliferation of Jurkat leukemia cells in vitro and protect the cells from apoptosis by activating Notch signaling, indicating a
potential shielding effect of MSCs on leukemia cells.