Establishment of stromal cell line from an MDS RA patient which induced an apoptopic change in hematopoietic and leukemic cells in vitro

Objective. We previously reported on the heterogeneity of bone marrow stromal cell function in supporting hematopoietic cell proliferation and differentiation in vitro among refractory anemia (RA) of myelodysplastic syndrome (RIDS) patients. Interestingly, stromal cells from some MDS RA patients induced an apoptotic change in CD34(+) hematopoietic cells. However, the mechanism responsible for this action was unclear. Materials and Methods. In the present study, we established a cloned stromal cell line (LS801) from an MDS RA patient by introducing recombinant SV40-adenovirus vector containing the SV40 early gene. Results. LS801 induced an apoptotic change in CD34(-) cells from normal subjects and cloned leukemic cells in a coculture system. When hematopoietic cells were cocultured but kept separate from LS801 by a 0.45-mu m Millipore membrane to prevent their attachment, the action of LS801 in inducing apoptosis of hematopoietic cells was inhibited. Additionally, no production of fas ligand, tumor necrosis factor a or interferon gamma in LS801 was observed. Conclusion. These findings suggest that the novel stromal cell line LS801 will shed light on research into the mechanism underlying the apoptotic changes induced by stromal cells in hematopoietic cells, (C) 2000 International Society for Experimental Hematology. Published by Elsevier Science Inc.