Clonal Heterogeneity of Human Bone Marrow-Derived Stromal Cells

Jung, Ho Sun; Kim, Yun Hee; Shim, In Hye; Han, Seung Hwan; Lee, Jin Woo

Abstract

PURPOSE
The isolated human bone marrow-derived stromal cells (BMSCs) were expanded and showed multipotentiality for differentiation to both adipocytes and osteoblasts. We selected the multiple clones and characterized their proliferation potentials, surface markers and differentiation potentials.
MATERIALS AND METHODS
BMSCs were isolated from bone marrow. After forming colonies, colonies were selected and cultured. We performed MTT assay and FACS. Cultured colonies were differentiated into adipocyte and osteoblast.
RESULTS
BMSCs were isolated and plated in tissue-culture dishes. The number of clones was about 30. Clones were divided into three groups. Group I was round and small in size, and showed rapid proliferation. Group II showed similar pattern in cell size and proliferation with group I clones during early passage. But, after 4 passages, the clones became flat and larger cells and showed slower proliferation. Finally, group III clones were flat and large cells and replicated slowly in early passage. Group I was fibroblastic in morphology, but Group II changed to flat and larger cells after passage 4. FACS and proliferation assay were performed at passage 5. Group I and Group II cells differed in their expression of the cell-surface epitopes, CD29 and CD105. Group I cells were differentiated into adipocytes better than Group II cells.
CONCLUSION
In this study, these results indicated that cell surface markers were expressed differently for clones having different differentiation properties. These clonal BMSCs may also be used for the identification of lineage-determining factors.