Influence of mesenchymal stem cells derived from bone marrow of children with
oncohematological diseases on proliferation and self-renewal of hematopoietic progenitor
cells in vitro
Ya. Isaikina*, T. Shman
Belarusian Research Centre for Pediatric Oncology and Hematology, Minsk, Belarus
Abstract. To test the ability of cultured mesenchymal stem cells (MSCs) from bone marrow
(BM) of children with oncohematological diseases after chemotherapy and radiation to
support proliferation and self renewal of hematopoietic cells in vitro. Methods: BM
samples of 8 patients and 9 healthy children-donors used for MSCs preparation applying
techinque of expansion in vitro. CD34+ cells were isolated from BM of donors.
The ability of MSCs to maintain hematopoietic stem cells (HSCs) proliferation was tested
in semisolid methylcellulose medium and in liquid long-term-culture (LTC) medium. Results:
The presence of MSCs derived from BM of patients in methylcellulose medium induced 2-fold
increase of the number of commited myeloid progenitors without cytokines, 7-fold increase
together with growth factors and 14-fold increase of the amount of earlier pluripotent
hematopoietic precursor cells (CFU-GEMM) compared to expansion of HSCs without MSCs and
cytokines. The presence of MSCs layer of patients in liquid LTC medium significantly
promoted the hematopoietic cells proliferation rate, measured on 7th, 14th and 21st day.
The total number of cells was multiplied 161.2-fold on 21st day as compared to 116.4-fold
without MSCs layer. In the presence of MSCs layer, we detected the increase of proportion
of bipotent CFU-GM precursors from 4% to 11% and pluripotent CFU-GEMM precursors from 0.1%
to 0.6% in population of HSCs. In both types of experiments the capacity of patients’
MSCs to support HSCs proliferation and self renewal was the same as for healthy donors’
MSCs. Conclusion: In this study, ÌSCs were isolated from BM of children with malignancies
after high-dose chemotherapy or radiation. The ability of these MSCs to maintain
hematopoiesis in vitro was tested. It was shown that co-transplantation of autologous MSCs
is a good way to improve hematopoietic stem cells engraftment and reduce a period of
granulocytopenia after autologous HSCs transplantation in case of insufficient CD34+
cell number in autologous transplant.