Growth kinetics and self-renewal of human mesenchymal stem cells derived from bone marrow of children with oncohematological diseases during expansion in vitro.

AIM

We investigated the ability of mesenchymal stem cells (MSCs) derived from bone marrow (BM) of children with oncohematological diseases after chemotherapy and radiation therapy to the self-renewal and proliferation for further expansion and their implementation as co-transplant, together with autologous hemopoietic stem cells (HSCs).

MATERIALS AND METHODS

BM samples from 20 patients with tumors and BM samples from healthy children-donors (for allogenic HSCs transplantation) were under study. The colony forming unit-fibroblast (CFU-F) assay and the colony forming unit-granulocytes and macrophages (CFU-GM) assay were used for the evaluation of MSCs and HSCs proliferative capacity. Mononuclear cells (MNCs) were plated 1 x 10(6). Following 14 days cells subcultured in primary culture (I passage) to study MSCs ability to self-renewal in culture. 6 passages were performed. The population doubling (PD) in each passage and the cumulative population doubling were calculated.

RESULTS

Data revealed 3-4-fold reduction of the mean incidence of CFU-F in patients after treatment compared to donors. The number of CFU-GM in patients was lower than in donors as well (39.0, 9.0-130.0 vs 95.0, 31-205). Correlation between numbers of CFU-F and CFU-GM was revealed in patients BM (r = 0.63, p < 0.003) as well as in healthy children. MSCs from BM possessed high potential to self-renewal. Their number increased 900-fold in primary cultures in the first 14 days and 17-fold in subculture in 60 days. The analysis of cumulative PD in patients and donors demonstrated the slowing of cell proliferation and telomere length decrease from passage to passage.

CONCLUSION

Despite the low content MSCs from BM of children with oncohematological diseases possessed high potential to self-renewal. The total number of MSCs can be increased 1.5 x 10(4) fold in 2 months period in vitro.