B-cell chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the world. It is characterized by the accumulation of mature, B cells in the blood, secondary lymphoid tissues and bone marrow. Circulating leukemia cells can develop resistance to programmed cell death (apoptosis) induced by standard chemotherapy. However, CLL cells undergo spontaneous apoptosis in vitro because they depend on stromal cells for their survival in vivo. This impedes the development of an efficient therapy to treat CLL. Therefore, to solve this problem, it is important to develop an in vitro model that can provide a suitable microenvironment that prevents CLL cells from undergoing spontaneous apoptosis in vitro. We have successfully isolated and characterized mesenchymal stem cells from human placenta (pMSCs). These cells can inhibit the proliferation and stimulate apoptosis of human T-Cell Leukemia cells in vitro. Therefore, we will develop a novel an in vitro model by co-culturing bone marrow mesenchymal stem cells (BMMSCs), T cells, dendritic cells and macrophages with CLL cells (B cells) isolated from CLL patients and then examine the effects of pMSCs on the functions of CLL cells. This study will provide the basis of future development of more efficient therapeutic strategies for CLL.
Photomicrographs showing (A) MSCs migrated out of placental chorionic villous tissue, and the differentiation of pMSC into (B) osteocyte as demonstrated by Alizarin Red S staining, (C) chondrocyte as demonstrated by Alcian Blue staining of cross-section and (D) adipocyte as demonstrated by HCS LipidTOX™ Green neutral lipid staining. Scale bars represent 50 µm. ((Abumaree et al., 2013)