cryopreserved CD34 positive human umbilical cord blood cells

Human umbilical cord blood cells (UCB) is an important alternative resource for the hematopoietic stem cells in treatment of leukemia and other non-malignant diseases. The failure of hematopoiesis reconstruction by the UCB is known to be associated with several clinicopathological features of host patients. There are very few reports available, however, seeking for the association with the quality of umbilical cord blood cells (UCB) themselves. Here we try to address the quality of UCBs by transfusion to the lethally irradiated immunocompromized mice. The cryopreserved CD34+ UCBs cells from twelve different single human donors were transplanted to the irradiated NOD/shi-scid Jic mice. In parallel, total RNAs of the UCBs were subjected to the gene expression profiling with oligonucleotide microarrays. The UCBs from three donors failed to establish the engraftment in the host mice whereas other 9 UCBs succeeded to various extents. Oligonucleotide microarray analysis indicated that 71 genes, including HOXB4 and ETS2, were specifically overexpressed and 23 genes were suppressed more than 2 fold in the successful UCBs comparing with the failed ones (p<0.005, Student’s t-test). Functional annotation analyses revealed that the genes mediated cell growth and cell cycle regulations were enriched in successful UCBs comparing with the failed ones. Our results suggest that the hematopoiesis reconstitution ability may vary among the cryopreserved UCBs and the quality can be distinguished with certain sets of gene expression. The gene expression in human umbilical cord blood cells (UCBs) was measured before transplantation to the lethally irradiated immunocompromized mice. UCBs from 12 individuals were examined.