The promise of stem cell research

Chances are very good you've heard about stem cells. Whether from reports of their almost miraculous ability to cure and restore, or very public controversies over their source or the research itself, stem cells have been a hot topic in the news for years.

The use of stem cells as therapy isn't new. "The curative component in bone marrow transplantations, which have been used to treat certain blood cancers for more than 40 years," says CNN Future Summit Nominating Committee Member Alan Colman, "is the small proportion of stem cells present."

Colman is the CEO of E.S. Cell International in Singapore, and was part of the team that cloned "Dolly" the sheep.

We all have stem cells. They're an integral part of our bodies. Long before you were born, they were creating the tissues and organs that make you who you are.

At the core of the research is the desire to use the unique way stem cells behave to heal a range of illnesses and ailments. These cells have the potential to develop into any of the 220 cell-types in the human body, and serve as a kind of natural repair mechanism. Theoretically they can keep dividing and re-dividing as long as an organism is alive, producing red blood cells, skin cells, muscle cells or whatever the body needs to keep going.

Understanding precisely how this process works and how these cells specialize could have a huge impact on healthcare. Ultimately it should be possible to use stem cells to replace any other cells in the body that have been damaged or harmed by accident and disease.

Many scientists believe the treatment of strokes, heart disease, cancer and birth defects could benefit from stem cell research, along with Parkinson's and Alzheimer's disease. "I do believe that Alzheimer's disease will be a target in the future," Colman says. "I don't think that people suffering from the disease can expect to get memories back that they have lost because those neurons, responsible for those memories, will have long been lost. But it will afford them a quality of life in their terminal years, which they wouldn't have without the use of stem cells."

Unfortunately, adults don't have a lot of stem cells available. And there's a difference between stem cells in adults and those in embryos just days old.

Colman explains that both embryonic and adult stem cells are important. "I think that we will find that each type of stem cell is good for some purposes and bad for others. Embryonic stem cells have the benefit that they can grow indefinitely in culture. Adult stem cells generally cannot do that."

"But on the other hand, adult stem cells," Colman says, "are nearer, if you like, to the end product than the embryonic stem cell. I think researchers should be backing both areas of research at the moment and the public also should support both types of research."

Researchers have been working to manipulate stem cells, in pursuit of treatments for a broad range of illnesses and ailments. The cells can be applied directly in the body, or used to grow replacement tissue in a laboratory.

The possibilities of stem cell therapy
Stem cell research promises to help fill gaps where current medicine falls short. "We believe that stem cells have uses in diabetes patients," says Colman, "where they have lost the ability to make insulin."

"There are things called mesenchymal stem cells which can be found in the bone marrow," says Colman, which can replace cartilage."

Colman believes stem cells may have a role in heart patients as well. "Bone marrow stem cells are now being used to repair hearts of people who have had myocardial infarctions."

One of those people is Ian Rosenberg, who suffered a heart attack in 1985. By 2003, time was running out. "My heart was in such bad shape," Rosenberg told CNN last year, "That they told me I had only two and a half months to live." Rosenberg underwent treatment at a hospital in Germany, and says, "my heart is pretty good now. I can go cruising, travel to America where I spend about six months of the year and walk a lot further than previously." (Full story)

"These are big unmet clinical needs," he says, "and we believe these are needs which can be met by stem cells in the next few years."

Repairing bone is something Colman believes "will be conquered in the next few years." And the thinks Alzheimer's patients may also benefit. "Not to give people back the memories that are lost, but just to allow them, as they go into their latter years, an increased quality of life."

How stem cells are being used today
The concept of using stem cells to repair damage to the spine or nervous system has been successful in animals. Last year, researchers at the University of California at Irvine announced they had successfully used adult human neural stem cells to treat mice with spinal injuries. (Full story)

Surgeons in London have been working to use stem cells to treat patients with damage to their nervous system. They'll take stem cells from the noses of their patients, which will mean there is no chance of rejection. If all goes well, the cells will patch a broken connection between nerves in the patient's arms and their spinal cord. (Full story)

Dorairajan Balasubramanian, Chairman of the National Task Force on Stem Cell Research and a member of the CNN Future Summit Nominating Committee, has been using stem cells to treat patients at the L.V. Prasad Eye Institute in Hyderabad. Last year, Edward Bailey described to CNN how the use of stem cells helped restore sight in his left eye. (Full story)

Seeking to understand stem cell development, British scientists earlier this year sought permission to fuse human cells with rabbit eggs. The scientists hope that the resulting embryos would allow them to better understand stem cell development. The embryos would not be allowed to develop. The matter is now being considered by the Human Fertilization and Embryology Authority. (Full story)

Challenges and controversies
There are some significant challenges ahead in the research.

Colman says identifying the right stem cells and converting them properly to the cells you need are the first task. "Then we have to ensure that once transplanted the cell behaves properly and integrates with the neighboring cells and tissues and that it doesn't run amuck." At question is whether stem cells grown in a laboratory will "respond to the cues in the body that say enough is enough. Stop growing now, you are at the right number."

The use of embryonic stem cells has become a social issue in some societies. Many religious groups find the idea of using cells from human embryos morally unacceptable.

Others believe the ability to heal the living outweighs those concerns. "My own view is that the embryo does have a moral status," says Colman, "but it's not equivalent to that of a living person, particularly not that of a sick living person."

Another controversy involving stem cell research erupted last year when it was learned that South Korean researcher Hwang Woo-suk faked results in nine of the 11 stem cell lines he claimed to have created.

That news stunned scientists and those who follow stem cell research. Colman says the incident in South Korea "gives the impression that all scientists, working in what is already a controversial area, are similarly, if you like, scurrilous and prone to fraud."

Colman says that's unfair. "Most scientists have great integrity and the experiments they do are fairly reported and there is no fraud attempted."

Balasubramanian says there must be an on-going conversation between scientists and the rest of society. "The role of scientists as interpreters," he says, "about advances in stem cell therapy, genetics and such is vital."

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