The effects of mesenchymal stem cells on lymphoblastic leukemia cell proliferation

Mesenchymal stem cells (MSCs) represent a new approach to the treatment of several neoplastic or non-neoplastic disorders. Their potential to repair damaged tissues through trans differentiation in conjunction with their immunomodulatory ability made them promising candidates for cell-based immunotherapy and regenerative medicine. In the present study, we aimed to determine the effects of MSCs on proliferation, apoptosis and gene expression profile of the acute lymphoblastic leukemia (ALL) cell line CCRF-CEM.

The experiments were performed after MSCs and CCRF-CEM cells were co-cultured for 72 hrs. We analyzed the gene expression patterns to predict oncogenic pathway dysregulation in the cell groups by quantitative RT-PCR and immunohistochemical staining.

Cell proliferation was significantly inhibited in co-cultured CCRF-CEM cells compared to the control. Furthermore, growth factors, p53, Bax and Caspase-9 expressions were increased and cell-signaling gene expressions decreased significantly. Despite increased levels of growth factors (CTGF, VEGF, FGF, EGFR), the increased apoptosis level was triggered by p53/ Bax.

In this study we have shown that human MSCs have inhibitory effect on their neighboring malignant leukemia cells.