Contributions
Type: Publication Only
Background
Mesenchymal stem cells MSC are main cells found in bone marrow BM microenvironment. They play a major role in hematopoietic stem cell HSC niche. These niches support acute myeloid leukaemia AML cells proliferation and differentiation.Many studies showed the protection of AML cells from chemotherapy induced apoptosis by BM microenvironment. The mechanism of this protection is still unclear.
Aims
Our present work is to compare the phenotype and functional properties of AML BM-MSCs to normal MSCs from BM to identify new mechanisms could help to improve the treatment of AML.
Methods
MSC were obtained from the BM of patients with AML and healthy donors (n = 5 per group). Following parameters were used for: cell morphology, cell proliferation test, cell cycle, immunophenotype, differentiation capacity into osteoblastic and adipogenic lineages. Gene expression profile was determined by Q-PCR.
Results
4/5 of AML BM-MSC have heterogenous morphology and 1/5 has homogenous fusiform, fibroblast-like appearance. AML BM-MSC show, significantly (p<0.05), low proliferative ability than normal BM-MSC, which induces an increase of doubling time (62,8 - / + 7h and 44,5 - / + 8h for AML and normal BM-MSC, respectively; p<0,01). The analysis of cell cycle show that the number of cells in AML BM-MSC cultures in G2/M phase, significantly p<0.05, reduced by 50% compared to normal BM-MSC cultures. However, Both of Normal and AML BM-MSC have similar immunophenotype profile (positive: CD90, CD73, CD105, CD166 and CD146; negative: HLA-DR, CD34, CD45). Both of cell types have a potential to differentiate into osteoblastic and adipogenic lineages showed by specific stains. This result was confirmed by the expression levels of Runx2, BMP2 and ALP Alkaline phosphatase (osteoblasts); and PPAR-γ2 (adipocytes). However, expression of these genes in osteoblasts derived from AML BM-MSC remains, significantly p<0.01, lower than the expression in osteoblasts obtained in normal BM-MSC differentiated cells.
Summary
The proliferative capacity of MSC obtained from the BM of patients with AML are limited and have a heterogenous morphology although the expression of phenotypic markers remains unchanged compared to normal BM-MSC. More significantly, the capacity to differentiate into osteoblasts is reduced in AML BM-MSC. This result suggest that, the bone quality obtained by AML BM-MSC is affected. Therefore, there is an influence on the endosteal microenvironment and that could affect the behavior of CD34 HSC in the endosteal niche.
Keyword(s): Acute myeloid leukemia, Gene expression profile, Mesenchymal stem cell
Type: Publication Only
Background
Mesenchymal stem cells MSC are main cells found in bone marrow BM microenvironment. They play a major role in hematopoietic stem cell HSC niche. These niches support acute myeloid leukaemia AML cells proliferation and differentiation.Many studies showed the protection of AML cells from chemotherapy induced apoptosis by BM microenvironment. The mechanism of this protection is still unclear.
Aims
Our present work is to compare the phenotype and functional properties of AML BM-MSCs to normal MSCs from BM to identify new mechanisms could help to improve the treatment of AML.
Methods
MSC were obtained from the BM of patients with AML and healthy donors (n = 5 per group). Following parameters were used for: cell morphology, cell proliferation test, cell cycle, immunophenotype, differentiation capacity into osteoblastic and adipogenic lineages. Gene expression profile was determined by Q-PCR.
Results
4/5 of AML BM-MSC have heterogenous morphology and 1/5 has homogenous fusiform, fibroblast-like appearance. AML BM-MSC show, significantly (p<0.05), low proliferative ability than normal BM-MSC, which induces an increase of doubling time (62,8 - / + 7h and 44,5 - / + 8h for AML and normal BM-MSC, respectively; p<0,01). The analysis of cell cycle show that the number of cells in AML BM-MSC cultures in G2/M phase, significantly p<0.05, reduced by 50% compared to normal BM-MSC cultures. However, Both of Normal and AML BM-MSC have similar immunophenotype profile (positive: CD90, CD73, CD105, CD166 and CD146; negative: HLA-DR, CD34, CD45). Both of cell types have a potential to differentiate into osteoblastic and adipogenic lineages showed by specific stains. This result was confirmed by the expression levels of Runx2, BMP2 and ALP Alkaline phosphatase (osteoblasts); and PPAR-γ2 (adipocytes). However, expression of these genes in osteoblasts derived from AML BM-MSC remains, significantly p<0.01, lower than the expression in osteoblasts obtained in normal BM-MSC differentiated cells.
Summary
The proliferative capacity of MSC obtained from the BM of patients with AML are limited and have a heterogenous morphology although the expression of phenotypic markers remains unchanged compared to normal BM-MSC. More significantly, the capacity to differentiate into osteoblasts is reduced in AML BM-MSC. This result suggest that, the bone quality obtained by AML BM-MSC is affected. Therefore, there is an influence on the endosteal microenvironment and that could affect the behavior of CD34 HSC in the endosteal niche.
Keyword(s): Acute myeloid leukemia, Gene expression profile, Mesenchymal stem cell