Outer lining of the umbilical cord is a rich source of stem cells

Jul 12 2005

CellResearch Corporation in Singapore and its team of scientists, headed by Chief Scientist, Dr Phan Toan Thang, have recently made a revolutionary discovery: that the outer lining of the umbilical cord is a rich source of stem cells.

Stem cells are elementary cells with the potential to form a spectrum of human cells - the tiny building blocks that make up the human being. These cells can be converted (differentiated) into a myriad of cells, giving them incredible potential to heal by forming cells that replace those that fail through disease, accident or old age.

So far, the most versatile stem cells are found in embryos as it is their job to produce the hundreds of cell varieties that make up the human being. However the process of harvesting stem cells from embryos has been a subject of much controversy as its use intrinsically involves the destruction of the embryo. To avoid ethical objections, scientists and biotech companies have been exploring and developing other stem cell sources, leading to the discovery, among others, of stem cells in cord blood.

While cord blood stem cells are rich largely in hematopoietic cells that form blood cells, they lack sufficient mesenchymal and epithelial stem cells. The latter two forms of stem cells are responsible for creating virtually every cell in the body. Stem cells can also be found in marrow, muscle, skin, nervous tissue and fat, however, their extraction would require surgical intervention which is both uncomfortable and has potential risks.

CellResearch Corporation's breakthrough is identifying an alternative source of stem cells that is not only easily accessible, but also possesses both epithelial and mesenchymal stem cells. These stem cells that are found in the outer amniotic lining of the umbilical cord have been successfully differentiated by CellResearch Corporation into specific cells such as skin, bone, and fat. The potential to form other cell types from these cord-lining stem cells is phenomenal and best of all, they are acquired from the afterbirth which is plentiful and routinely discarded, thus sidestepping the whole ethical conundrum. CellResearch Corporation has applied for patent protection for its discovery.

Another advantage of cord-lining stem cells is its significantly higher yield compared to other sources. Laboratory results show that the cord lining produces potentially several hundred million stem cells per cord - a figure that is many hundred folds greater than most common stem cell sources.

Most interestingly, cord-lining stem cells may possess embryonic stem cell characteristics which infer that they may have pluripotent capabilities (the ability of a single cell to develop into multiple types of cells). These are reflected in the genetic markers they expressed in recent experiments conducted by CellResearch Corporation. Stem cells from fat, cord blood and bone marrow have not been found to express these markers. "These cord lining stem cells look promising because of their origin. To date, some preliminary experiments have been performed and while it is too early to comment on results, initial data has been favourable." says Sir Roy Calne, FRS, Professor of Surgery Emeritus, Cambridge University. Calne is involved in experimental work aimed at producing adult stem cells that secrete insulin and respond to glucose.

The next pressing issue in today's stem cell debate is whether stem cells can actually be safely used in practical clinical therapies: traditional laboratory cell growing (culture) techniques require stem cells to be nourished using serum derived from calf fetuses. These non-human components have been criticized as calf serum might potentially transmit bovine spongiform encephalopathy (mad cow disease). CellResearch Corporation has been able to clear this hurdle by growing the cells without the need for calf sera by using serum-free media for cell culture. "Their potential for clinical use is, as a result, multiplied many fold," says Dr Ivor Lim, Medical Director of CellResearch Corporation.

Overall, the commercial applications of these cord lining stem cells are far reaching. Their ability to morph into a variety of cells means that they can potentially be used to treat a wide range of diseases from diabetes to Alzheimer's disease. The US$11 billion diabetes market (Source: Freedonia), US$15 billion cancer therapy market (Source: BCC, Inc.), and US$45.5 billion anti-ageing products and services market (Source: BCC, Inc.) are just some of the medical industries that may benefit from this discovery. Wound healing and the development of bioengineered skin are two additional areas of expertise which CellResearch Corporation intends to focus on.