Bone Marrow Mesenchymal Stem Cells Are Altered in B-Cell Chronic Lymphocytic Leukemia

• Published in: Blood 2008-11, Vol.112 (11), p.2066-2066
• Main Authors: Pebrel-Richard, Céline, Masson, Richard Veyrat, Dubois-Galopin, Frédérique, Guérin, Jean-Jacques, Guillouard, Laurent, Chassagne, Jacques, Bay, Jacques-Olivier, Tournilhac, Olivier, Tarte, Karin, Berger, Marc G
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V112.11.2066.2066

In B-cell chronic lymphocytic leukemia (B-CLL), CD5+CD19+ malignant cells home into the bone marrow (BM) and circulate in the blood. While CLL tumor cells are not susceptible to apoptosis in vivo, they die rapidly in vitro in the absence of specialized non-hematopoietic feeder cells, such as mesenchymal stem cells (MSC). Recent observations have suggested that there is a functional relationship between B cell clone and the stroma. We have thus compared BM-MSC obtained from B-CLL patients and healthy subjects. We first evaluated the influence of in vitro culture conditions on the number of BM-derived CFU-F and the proliferation of MSC and, in parallel, we quantified in unmanipulated normal and malignant BM samples the CD45negCD14negCD73pos cell subset that was previously shown to contain CFU-F (Veyrat-Masson et al., BJH, 2007). Changes in the level of 42 cytokines/chemokines, were then evaluated in MSC-conditioned media (4 CLL vs 4 normal BM-MSCs) using protein-array (RayBio Human Cytokine Antibody Array IIITM, Tebu-bio SA,). In addition, total RNA was extracted (Rneasy MiniKit, Qiagen,) from 9 expanded MSC at passage 1 (P1) in the presence of bFGF (5 untreated B-CLL BM-MSC: 2 Binet stage A, 2 stage B and 1 stage C; 4 normal BM-MSC) and then reverse transcribed (High Capacity cDNA RT Kit, Applied BioSystems). Quantitative PCR reactions, using dedicated microfluid cards screening 384 selected genes, were then performed (TLDAs, Applied Biosystem Courtaboeuf, France). The expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used to normalize gene expression level. Despite a 16-fold increase in total cell numbers tested, we found that most BM-MSC cultures from B-CLL patients failed under standard culture conditions (IMDM/10%FCS), in contrast with our experience with normal BM (69 % n = 13 vs