Related Experiment Videos
Functional characterization of fibroblastic cells in long-term marrow cultures from patients with acute myelogenous
H Mayani1, L J Guilbert, A Janowska-Wieczorek
1Department of Medicine, University of Alberta, Canada.
Abstract:
We have investigated the role of acute myelogenous leukemia (AML) marrow-derived fibroblastic cells in the development of the hemopoietic microenvironment in vitro, and compared their functional integrity with that of their normal marrow-derived counterparts. Our results indicate that the development of stromal adherent layers in AML long-term marrow culture (LTMC) depends to a large extent on the presence of fibroblastic progenitors (fibroblast colony-forming units, CFU-F) in the bone marrow inoculum. Positive correlations were observed between the numbers of CFU-F in fresh AML marrow samples (nine cases studied) and the numbers of adherent nucleated cells (r = 0.91), adherent CFU-F (r = 0.87), adherent hemopoietic progenitors (r = 0.71), and colony-stimulating factor-1 (CSF-1) levels (r = 0.74) in LTMC. All the above parameters were drastically reduced in LTMC derived from AML marrows that contained low numbers of CFU-F (i.e. below the normal range of 76-130 CFU-F per 10(6) bone marrow cells) when compared with LTMC established from normal marrows. In contrast, no difference was observed in such parameters when normal LTMC and LTMC from AML patients with normal levels of marrow CFU-F were compared. Fibroblast adherent layers derived from AML patients with normal marrow CFU-F numbers produced normal levels of CSF-1 and showed a similar hemopoietic supportive capacity to that of fibroblast layers from normal bone marrow. Thus, our results suggest that (i) the presence of CFU-F in adequate levels in the bone marrow inoculum is critical for the adequate development of the hemopoietic microenvironment in LTMC, and (ii) AML marrow-derived fibroblasts seem to be functionally normal, at least in some AML patients.
Insights
Adequate fibroblast progenitors (CFU-F) are crucial for developing the bone marrow microenvironment in acute myelogenous leukemia (AML) cultures. AML-derived fibroblasts appear functionally normal when CFU-F levels are sufficient.
Area of Science:
- Hematology
- Cell Biology
- Oncology
Background:
- The bone marrow microenvironment is essential for hematopoiesis.
- Acute myelogenous leukemia (AML) can disrupt normal marrow function.
- Fibroblastic cells play a key role in supporting the hemopoietic microenvironment.
Purpose of the Study:
- To investigate the role of AML marrow-derived fibroblastic cells in hemopoietic microenvironment development.
- To compare the functional integrity of AML-derived fibroblasts with normal counterparts.
- To assess the impact of fibroblast progenitors (CFU-F) on AML long-term marrow culture (LTMC).
Main Methods:
- Establishment of long-term marrow cultures (LTMC) from AML and normal bone marrow samples.
- Quantification of fibroblast colony-forming units (CFU-F) in bone marrow inoculums.
- Measurement of adherent nucleated cells, adherent CFU-F, hemopoietic progenitors, and colony-stimulating factor-1 (CSF-1) levels in LTMC.
- Comparison of LTMC parameters between AML and normal samples based on CFU-F levels.
Main Results:
- Development of stromal adherent layers in AML LTMC strongly correlates with the presence of CFU-F.
- Low CFU-F numbers in AML marrows led to drastically reduced adherent cells, CFU-F, hemopoietic progenitors, and CSF-1 levels in LTMC compared to normal.
- AML patients with normal CFU-F levels showed no significant differences in LTMC parameters compared to normal controls.
- Fibroblast layers from AML patients with normal CFU-F produced normal CSF-1 and supported hematopoiesis similarly to normal fibroblast layers.
Conclusions:
- Adequate levels of fibroblast progenitors (CFU-F) are critical for the proper development of the hemopoietic microenvironment in LTMC.
- Fibroblasts derived from AML marrow appear functionally normal, provided sufficient CFU-F are present.
- The study highlights the importance of fibroblastic stromal cells and their progenitors in maintaining bone marrow function, even in the context of AML.