Cord blood cells appear to be far more versatile to treat many diseases than previously considered. Two teams had successfully reprogrammed cord blood cells to exhibit properties similar to embryonic stem cells. Reprogrammed cells that have embryonic-like stem cell characteristics are called induced pluripotent stem (iPS) cells.
Their results are published online today (October 2, 2009) in the journal Cell Stem Cell.
The success is significant as nearly 400,000 cord blood units are already stored in many banks, both private and public, and they have the potential to produce unlimited number of iPS cells.
Scientists were first able to reprogramme adult skin cells into iPS cells in 2006. But reprogramming adult skin cells into iPS cells has certain challenges. Skin cells, compared to cord blood cells, are old, and hence have greater chances of accumulating genetic errors through mutations. Reprogramming efficiencies are also lower. There are also issues with harvesting adult cells.
Cord blood cells have none of these shortcomings. Since they are very young, the chances of mutations getting accumulated are far less. Higher reprogramming 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 are a readily available source for producing iPS cells as they are already collected and stored. Harvesting cord blood is easy, safe, has less chances of contamination, and does not cause harm to the mother or infant.
According to Alexandra Haase from 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 reprogrammed, a real alternative for a safer source of iPS cells,” Dr. J.C. Izpisua Belmonte from 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 the cord blood cryopreserved for more than five years were able to produce iPS cells. “These data showed that the standard cryopreservation protocol does not affect the reprogramming ability of these cells,” the paper by Dr. Belmonte et al notes.
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, including functional heart muscle cells.
The potential to treat many diseases is immense when cord blood is reprogrammed 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.