Doctor Beverly, would you like to post the material you shared a few days ago regarding MAPC's? It was most instructive regarding adult stem cells.
From an article that is unfortunately not available for free. I will forward the complete article to anyone who is interested.
Unexpected Potential of Adult Stem Cells
C. M. VERFAILLIE, R. SCHWARTZ, M. REYES and Y. JIANG Stem Cell Institute, Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA Address for correspondence: Dr. Catherine Verfaillie, University of Minnesota Medical School, 420 Delaware Street S.E., MC716, Minneaplois, MN 55455. Voice: 612-625-0602; fax: 612-624-2436. verfa001@tc.umn.edu Ann. N.Y. Acad. Sci. 996: 231-234 (2003).
Key Words: multipotent adult progenitor cells cell differentiation
We have isolated from marrow of humans, mouse, and rat, cells that we have termed multipotent adult progenitor cells or MAPCs.1-5 MAPCs appear in mesenchymal stem cell cultures after 25-35 population doublings, provided that cultures are maintained on fibronectin, not collagens or laminin, in the presence of low amounts or no fetal bovine serum, and in the presence of epidermal growth factor and platelet-derived growth factor, supplemented with leukemia inhibitor factor in mouse and rat. In addition, MAPCs are only found when cells are plated and maintained at low density, and are not allowed to grow to semi-confluence or confluence. When maintained under these conditions, MAPCs from 60% of human bone marrow have been culture-expanded for more than 50 and up to 80 population doublings, and MAPCs from mouse and rat bone marrow have been expanded for more than 80-150 population doublings. Of note, this expansion is not associated with obvious genetic instability, as cytogenetic evaluation of all human and rat cultures, and all but two subpopulations of mouse cultures have not revealed cytogenetic abnormalities, suggesting that this may not be the result of a transforming event. However, the status of most oncogenes and anti-oncogenes has not yet been evaluated. Furthermore, telomeres are apparently stable in mouse, rat, and human MAPC cultures, and telomerase is active. (emphasis is mine)