Bone marrow cells adopt the phenotype of other cells by spontaneous cell fusion

Bone marrow‐derived very small embryonic‐like stem cells: Their developmental origin and biological significance

“…Hypothetically, such a "permissive" environment could induce epigenetic changes in HSC and, thus, force them to change lineage commitment (Morshead et al, 2002;Pomerantz and Blau, 2004). Second, it has been postulated that some plasticity data could be explained simply by the phenomenon of cell fusion (Terada et al, 2002;Ying et al, 2002;AlvarezDolado et al, 2003;Vassilopoulos et al, 2003;Nygren et al, 2004). Accordingly, the donor-derived cells observed in damaged tissues that express nonhematopoietic markers could be in fact heterokaryons, the result of the fusion of BM-derived stem cells with somatic host cells in the damaged organs.…”

Adult Stem Cell Plasticity: Dream or Reality?

“…Another example of fusion is between bone marrow stem cells and liver cells to generate hepatocytes in mice. Two recent studies documented that co-culture of adult tissue cells with ESC also leads to cell fusion [26].…”

“…In patients in whom autologous bone marrow cells were injected directly into the damaged myocardium, some improvement in cardiac function was documented based on medication use, quality of life and MRI studies [17]. In a separate study, after autologous AC 133+ bone marrow cells were injected into infarction borders following coronary artery bypass grafting (CABG), improved perfusion and cardiac function may have occurred [18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Adult bone marrow–derived stem cells for organ regeneration and repair

“…These results are not unequivocally accepted and might be due to a mechanism different from transdifferentiation or plasticity. Alternative explanations for their proposed plasticity included fusion (Terada et al, 2002;Ying et al, 2002), methodological problems (Raff, 2003), restriction to a model system/disease state, and presence of embryonic stem cell-like cells in the injected cell population. Plasticity is not a frequent phenomenon and does not usually occur under steady-state conditions (Wagers et al, 2002;Wagers and Weissman, 2004), however, it can be very powerful in certain model systems, and even if fusion is the primary mechanism, exploitation of stem cell plasticity might yet prove to be a useful therapeutic tool for otherwise incurable diseases.…”

“…However, the finding of cell fusion (Terada et al, 2002), and the fact that only a small number of transdifferentiated cells (Ͻ 0.1% of all tested cell types) could be detected in the injured organ post transplantation, made it unlikely that cell engraftment is the main therapeutic principle. Fusion can be interpreted as a form of gene delivery into cells with a genetic defect, as illustrated in a model of liver damage caused by a defect in the fumarylacetoacetate hydrolase enzyme.…”