Comparing the gene expression profile of stromal cells from human cord blood and bone marrow: lack of the typical "bone" signature in cord blood cells.

With regard to the bone-regenerative capacity, bone marrow stromal cells (BMSC) can still be termed the "gold standard." Nevertheless, neonatal stromal cells from cord blood (CB) feature advantages concerning availability, immaturity, and proliferation potential. The detailed gene expression analysis and overexpression of genes expressed differentially provide insight into the inherent capacity of stromal cells. Microarray and qRT-PCR analyses revealed closely related gene expression patterns of two stromal cell populations derived from CB. In contrast to the CB-derived cell types, BMSC displayed high expression levels of BSP, OSX, BMP4, OC, and PITX2. Lentiviral overexpression of BSP but not of OSX in CB-cells increased the capacity to form a mineralized matrix. BMP4 induced the secretion of proteoglycans during chondrogenic pellet culture and extended the osteogenic but reduced the adipogenic differentiation potential. BMSC revealed the typical osteogenic gene expression signature. In contrast, the CB-derived cell types exhibited a more immature gene expression profile and no predisposition towards skeletal development. The absence of BSP and BMP4-which were defined as potential key players affecting the differentiation potential-in neonatal stromal cells should be taken into consideration when choosing a cell source for tissue regeneration approaches.