Stem Cells Come in All Shapes and Sizes

Louisville, KY –

Stem cells from adult sources (non-embryonic) are generally believed to be restricted in differentiation potential. However, there are several reports of stem cells from bone marrow and cord blood that express makers of pluripotency. For example, in 2004 Prockop’s group from Tulane reported that if one incubates early passaged human bone marrow derived mesenchymal cells in absence of serum or cytokines, after 2-4 weeks, the cells that survive are in possession of embryonic stem cell markers and in some situations had pluripotent differentiation ability (Pochampally et al. Serum deprivation of human marrow stromal cells (hMSCs) selects for a subpopulation of early progenitor cells with enhanced expression of OCT-4 and other embryonic genes. Blood. 2004 Mar 1;103(5):1647-52)

Today, on Pubmed appeared the abstract for a paper (Kuci et al. Morphological and molecular characterization of novel population of CXCR4 SSEA-4(+) Oct-4(+) very small embryonic-like cells purified from human cord blood - preliminary report. Leukemia. 2006 Nov 30) describing what appears to be early embryonic like stem cells in cord blood. In contrast to other types of cord blood stem cells, these ones have a very small size and a phenotype of Oct-4+, Nanog+, SSEA-4+, as well as expressing CXCR-4, AC133, CD34, but lacking CD45 and lineage markers.

These cells, which the authors termed very small embryonic-like (VSEL) stem cells could be a great source for development of novel stem cell populations to circumvent current patent holdings.