Figure 1.

MSC originated from MDS patients and healthy donors possess clonality and have different characteristics. (A) MSC are characterized by increased frequency of cells with a dysplastic appearance (lower panel, Giemsa staining 10× magnification, insets showing a cell in detail) and produce disorganized stromal layers (upper panel, 10× magnification). (B) MSC are able to generate fibroblastic colonies across two passages (P, and SubP) in all studied groups. (C) MSC can produce single cell derived (SCD) colonies; these colonies retain self-renewal and clonogenic potential (SubP-SCD). (D) MSC derived by plastic adherence and by SCD plating have distinct degrees of osteogenic and adipogenic potential, as seen by van Kossa staining (first 2 rows, 20× magnification) and by oil red staining (second 2 rows, 20× magnification). Results are expressed as mean ± SEM of independent cases, for (B) numbers were Healthy=6, LR-5q=6, LR=6 and HR=5; for (C) n=4 for all groups and n=3 for SubP. Significance was set as *P≤0.05; **P≤0.005; ***P≤0.001.