Cord blood cells appear to be far more versatile to treat many diseases than previously considered. Two teams have successfully re-programmed cord blood cells to exhibit properties similar to embryonic stem cells. Re-programmed cells that have the characteristics of the embryonic-like stem cells are called induced pluripotent stem (iPS) cells.
Their results have been published in the online version of the journal Cell Stem Cell.
The success is significant as nearly 4,00,000 cord blood units are stored in many banks, both private and public, and they could produce an unlimited number of iPS cells.
Scientists first re-programmed adult skin cells into iPS cells in 2006. But the process has certain challenges. Skin cells, compared with cord blood cells, are old, and hence have greater chances of accumulating genetic errors through mutations. Re-programming efficiencies are also lower.
Further, there are issues with harvesting adult cells. But cord blood cells have none of these shortcomings. Since they are very young, the chances of mutations getting accumulated are far less. Higher re-programming efficiencies can be achieved as demonstrated by both the teams. One of the papers found that cord blood cells had nearly 50 per cent chances of acquiring human embryonic-like stem cell characteristics.
Most importantly, cord blood units become a readily available source for producing iPS cells, as they are already collected and stored. Harvesting cord blood is easy and safe. It has less chances of contamination and does not cause harm to the mother or infant.
According to Alexandra Haase of the Hannover Medical School, Germany, the first author of one of the papers, cord blood cells outperformed adult blood stem cells on several counts.
"We believe that cord blood cells could represent, rather than just another cell type that can be re-programmed, a real alternative for a safer source of iPS cells," J.C. Izpisua Belmonte of the Center of Regenerative Medicine in Barcelona, Spain, the senior author of the second paper, was quoted as saying in Cell Press.
Dr. Belmonte and his team found that cord blood units cryopreserved for more than five years were able to produce iPS cells. "These data showed that the standard cryopreservation protocol does not affect the re-programming ability of these cells," says the paper by Dr. Belmonte et al.
The other team was able to demonstrate that the iPS cells produced from cord blood cells had the potential to differentiate into multiple mature cell types. The potential to treat many diseases is immense when cord blood is re-programmed to iPS cells. Cord blood units stored in private and public banks have a great potential to treat many diseases. However, unlike those stored in private banks, the units stored in public banks provide an almost unlimited number of cells for producing iPS cells that can be used for treating unrelated persons.
"Cord blood could readily become available for paediatric patients and, in particular, for newborns with genetic diseases or congenital malformations," the paper by Dr. Haase et al notes.
