Comparison of effects of mesenchymal stem cells derived from bone marrow of patients with childhood acute lymphoblastic leukemia and healthy donors on leukemic blasts

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood. Despite the high rate of cure, ALL is one of the leading causes of death in children. The bone marrow microenvironment plays an important role in the initiation and progression of leukemia. Various components of this microenvironment, particularly MSCs, regulate ALL survival, proliferation, and drug resistance by producing growth factors, cytokines, and intracellular signals. The exact role of MSCs in leukemic cell survival is not well known, but probably they show their effects through secreting various cytokines or interact with the leukemic cells. In our study, the apoptotic effects of MSCs of patients with childhood ALL and healthy donors on blastic cells were investigated in vitro by coculturing without cell-cell contact (with membrane) and providing cell-cell contact (without membrane). Apoptotic properties of blasts were analyzed by flow cytometry. The expression studies of β-catenin and Bax, Bcl-2 and Caspase 3 which are apoptotic proteins were determined as immunocytochemical methods in MSCs. According to the result of coculture studies, when apoptotic rates of healthy-patients and with membrane, without membrane gorups were compared, it was found out that there is no difference in the MSCs interaction with blasts of healthy donors and patients whereas it was seen that apoptosis rates of the blastic cells which were cocultured with and without membrane changed. In addition, it was noticed that β-catenin, Bcl-2, Bax and Caspase 3 expression of MSCs showed changes in patients and healthy donors as well. Keywords: Apoptosis, childhood acute lymphoblastic leukemia, mesenchymal stem cell, β-catenin