Résumé
This study was aimed to investigate the changes of differentiation and gene expression of CD133(+) cells in human umbilical cord blood induced by stem cell factor (SCF) and basic fibroblast growth factor (bFGF) in vitro, and to explore the biological characteristics of CD133(+) cells so as to provide experimental basis for potential use in regenerative medicine. The human umbilical cord blood CD133(+) cells were isolated from umbilical cord blood and purified by MACS magnetic selection. The CD133(+) cells were cultured in DMEM/F12 medium containing SCF, bFGF and B27 for 10 to 15 days. The total RNA of these cells was extracted before and after culture, and the analysis of related gene expression levels of these cells was performed using oligonucleotide microarrays. The results showed that out of 263 genes 21 genes were obviously up-regulated after culture than that before culture, whereas 7 genes were found to be significant down-regulated as compared with fresh-separated CD133(+) cells. These genes were involved in stem cell specific markers, cell cycle regulators, stem cell differentiation markers and signaling pathways that are important for stem cell maintenance. It is concluded that SCF and bFGF can induce differentiation of human cord blood CD133(+) cells through up- or down-regulation of specific genes. This study provides gene expression information for SCF and bFGF-induced human cord blood CD133(+) cells and contributes to understand the effect of SCF and bFGF on proliferation and differentiation CD133(+) cells at gene level, and promotes therapeutic applications of the CD133(+) cells induced by SCF and bFGF.