Every week we see more stories in the media about new ways to rebuild or repair damaged liver, heart, brain, spinal cord, eyes and so on.
What is the truth about this revolutionary technology? How much is really available now? When will organ regeneration become routine?
25 years ago I predicted the stem cell revolution, in one of my 16 books, The Genetic Revolution. Since then, I have worked with many of the world’s largest pharma companies, helping them understand the future role of human stem cells in organ repair and regeneration, as a physician and Futurist keynote speaker.
Here is the truth about stem cells - with useful references below.
The key to all organ regeneration and repair is stem cells
Stem cells are primitive cells which have the capacity to grow into many different types of organs.
We now know that whenever an organ in your body is injured, these special cells are released by the bone marrow into the blood, which automatically search out areas of damage.
The cells migrate to where they are most needed, and help in repairs. In most cases we think the way they do this is by producing special chemicals such as cytokines, and other proteins or fats, which stimulate local regeneration.
The good news is that doctors have decades of experience of using stem cells in health care, treating people with advanced leukaemia which is cancer of the bone marrow.
And we can find stem cells in many different parts of the body.
Over 1.5 million stem cell treatments already
Over 1.5 million people with leukaemia had been treated with stem cells by the end of 2017, in over 80 nations – with over 80,000 new treatments every year.
In 47% of cases, bone marrow is donated, usually by a close family member with the same tissue type (allogenic transplants).
53% have been treated with their own stem cells removed from their own body before treatment (autologous transplants).
Cancer specialists routinely remove samples of bone marrow, separate out the stem cells and store them, before giving someone a massive dose of radiation.
As soon as it is complete, and all their bone marrow cells have died, they transplant healthy stem cellsback into their bone marrow.
These divide rapidly, populating the entire bone marrow to regrow both red and white blood cells, and hopefully the person recovers.
The major risk is temporary loss of immune system and becoming very ill from serious infections.
Adult stem cells can do everything we need - forget embryo stem cells
Ten years or more ago, many so-called experts claimed that the only useful source of stem cells for organ repair was human embryos.
The trouble is that using tissue from human embryos has huge ethical issues for many people, including Christians, Muslims and Orthodox Jews.
For over 20 years, I have been saying that these experts were wrong.
It was obvious to me that we would be able to use adult stem cells, from the same body as someone needing treatment, and events have proved me correct.
So today for example, scientists are growing new retinal tissue to help blind people see, from skin cells.
Yes, that is correct. In every organ, including the brain, we can find immature cells, or stem cells, with varying degrees of specialization.
We can treat these same cells with chemicals to trick them into thinking that they are back in an embryo, or in a human foetus implanted into the womb.
A further step is to bath the cells with other chemical messengers, which make the cells think they are in a particular part of the body – the eye for example, and that they need to transform into retina, or cornea or whatever.
And scientists are getting superb results from these kinds of experiments.
So much so that very few stem cell researchers today are as excited as they were about using embryo cells.
For a start, such cells almost always risk being rejected as soon as they are transferred into a child or adult.
In contrast, when a person’s own cells are used to rebuild their own organs, by definition we have a perfect match.
How far can we go in organ regeneration and how do stem cells really work?
In both cases the answer is that we don’t yet know but results so far have been astonishing.
Take heart disease for example. For some years, doctors have been extracting stem cells from the bone marrow of heart patients, growing them in the lab and injecting them directly into heart muscle, or perfusing the arteries of the heart.
We know that some kinds of stem cells automatically migrate to areas of damaged tissue, where they settle down to help make a repair. This is a natural process and seems to go on inside our bodies every day.
There is a great debate between stem cell researchers about whether such stem cells actually transform into useful heart muscle, or whether they just produce special proteins which aid repair.
Who knows, and really it does not matter.
The most important thing to understand is that heart function often improves. These stem cell treatments help the heart to recover normal strength in a way that feel near miraculous compared to heart treatments 20 years ago.
Can we do the same for the brain?
The answer is almost certainly yes. In animal studies, scientists have been able to restore some brain function after stroke damage, or after other brain injuries, including chronic brain conditons, neurodegenerative diseases like Multiple Sclerosis or Motor Neurone Disease.
The brain has one very distinctive feature. Every blood vessel is lined by what we call the Blood Brain Barrier – designed to protect the brain from attack.
And this same barrier is an excellent screen against many of the white cells that patrol our bodies looking for foreign invaders such as bacteria or viruses.
But these same cells are the ones which can reject and destroy transplanted cells from other people.
What this means is that when it comes to brain repair, we are able to grow cell lines in the lab, from adult stem cells, which can in theory be injected into the brains of a large number of different people, without those cells being rejected.
Harvesting brain stem cells from the olfactory bulb (nose)
A good source of specialist stem cells from the central nervous system is from the upper part of the nose. Right up near your frontal sinuses is a structure called the olfactory bulb. This is connected directly to your brain, through a tiny hold inside the skull.
The bulb is packed with nervous tissue, and is coated with cells which sense smell.
An easy way to harvest vast numbers of adult stem cells suitable for the brain is to remove the olfactory bulb - although it means the person loses their ability to smell, which also impacts the way we "taste" food since most of the flavours we enjoy are actually sensed as aromas in the nose.
If you want proof of this, try eating some flavoursome food when holding your nose closed with your fingers.
Why stem cell trials are expanding so fast - lack of controls
In hospitals all over the world, stem cell clinical trials are progressing rapidly – now researchers have realized they can abandon attempts to use embryo cells because adult stem cells are a better alternative.
One reason why the research is developing so rapidly is that stem cell therapy bypasses almost all the steps needed in a normal $1 billion drug development process for a pharma company.
In drug trials, the first step is proving some kind of effect on human or animal tissue in a laboratory. The next step is animal studies for safety and impact.
After that comes Phase I clinical trials which are designed only to show the product is safe for use in humans.
Phase II clinical trials are small studies looking at impact on disease, followed by much larger Phase III trials, hopefully leading to strong evidence of benefit, and to a licence for sale.
But in the case of stem cells, there is no product to be tested. We are using living cells.
Stem cell research is not held back by normal drug trial regulations
And because the cells themselves come from the person who is being treated, doctors don’t even need the normal permissions to carry out studies. Their stem cell research cannot be regulated by normal drug development agencies.
After all, a patient can demand that cells removed earlier from their own body, are returned to their own body.
The cells belong to the patient so how can a regulatory authority insist that those stem cells be thrown away?
If a sick person has been informed of all the risks of extracting, treating and processing some of their own cells before injecting them back inside their own bodies, then it can be argued that most of the ethical issues have been dealt with.
Unregulated stem cell clinics springing up in many nations
It also means that stem cell clinics are springing up all over the world, offering highly experimental treatments, often at high cost, often without rigorous scientific data published in respected research journals, proving that their methods actually work.
Just one example is a doctor who has been injecting bone marrow stem cells into eyes of people who are blind, claiming that many patients have had partially restored sight as a result.
In the meantime, a large number of animal studies using stem cells are also showing benefit – for example for retinal repair.
Here are some examples of stem cell results in humans
Brain
Stem cells are being injected into the brains of people with Parkinsons Disease, who are lacking in brain cells which produce dopamine.
The work is in early stages and there are of course concerns that such cells might go on dividing too rapidly, creating some kind of brain tumours.
But first studies seem to show reduction in symptoms in some patients.
As is the case with repair of heart muscle using stem cells, we are uncertain about how these cells benefit brain function. The answer is likely to be a combination of neurogenesis (formation of new nerve cells), generation of new blood vessels, and release of proteins of various kinds which assist existing cells within the brain to recover and repair the damage.
Up to 10 million mesenchymal stem cells from bone marrow have been injected into patients with stroke, through holes in the skull, with what appears to be positive results.
It is hard to be certain because people with stroke tend to see improvements as part of normal recovery, but their doctors reported unexpected gains in movement and speech capability.
We know from studies in rats that these bone marrow stem cells do not survive in the brain for long, but they produce large amounts of special proteins which stimulate natural brain repair and growth mechanisms.
Liver
Stem cells are being explored as a therapy for liver cirrhosis. Good results have been seen in animal studies. https://www.medicalnewstoday.com/articles/297102.php
Spinal cord
Spinal cord damage is complicated because of a glue that that the body makes in response to spinal injury.
This glue is a terrible problem because it tangles up the ends of broken nerves as they begin to regrow. If you cut a peripheral nerve in your hand or arm for example, it is not long before the neurons begin to grow again, creeping their way down the old nerve sheath so long as it is carefully stitched back into place.
Nerves grow at around 3mm a day, so the recovery is significant in many cases. And exactly the same could happen in theory after a big spinal injury. So stem cells are being used to try and restore the normal environment in the damaged area of the spine, with some success.
Retina
As I said above, many different methods are being used to help restore sight in people who are blind.
In one technique, skin cells have been used to grow sheets of light sensitive retinal cells. These are inserted through a small cut in the eyeball, and placed onto the surface of the back of the eye, glued into location by lasers.
After a few weeks, some of those cells, in some people treated, have become established and connected up to the optic nerve. This is a treatment for people with macular degeneration.
Pancreas
Stem cells have been used to create new insulin secreting cells.
When they are injected back into the pancreas of someone with Type I diabetes, it is not long befire their immune system destroys them in a repeat of slywhat happened previously. So researchers came up with an ingenious plan.
They created a plastic-type membrane as a bag, which has holes large enough to allow nutrients such as sugar and amino acids in to feed the insulin cells, but small enough to prevent those cells escaping, and to prevent white soldier cells from entering to attack.
When these bags are placed inside the body, the person is able to make pure human insulin again.
Regrowing fingers, toes, arms or legs
1.5 million people in America alone are missing one or more limbs.
Newts are well known for their ability to regrow a lost tail. And other species are also able to regenerate severed limbs.
Stem cells have now been used to grow a new limb for rats. The technique is complicated, and involves preparing a scaffold onto which new stem cells can become attached to form new tissues.
The scaffold is made from the corresponding limb of a dead animal, with cells dissolved away, leaving the extra-cellular matrix, including the sheaths of nerves. The new limb has then been successfully attached to a live animal. A similar process has been used to grow artificial kidneys, bladders and so on.
Drugs which tell your own stem cells to repair your organs
Once we recognize the extraordinary fact that your own bone marrow has the ability to help repair organs around the body, it raises a very important possibility.
Back in 2003, I predicted that we would one day be able to give sick people a couple of injections to prepare the body and then trigger release of tens of millions of their own stem cells from their bone marrow. We are now very close to seeing this as a routine treatment.
This is really important. If it works well, it would mean that we don’t need any longer to go to all the trouble to extract stem cells, treat them, grow them and inject them back.
And it also means that for the first time, pharma companies can enter the stem cell revolution.
The trouble about stem cell therapy from the pharma compay point of view is that there is no actual product. The only thing we are giving the patient is their own cells. The only commercial benefits therefore are for companies selling equipment to extract stem cells, protect and grow them in the laboratory and so on.
Risks of stem cell therapy
All experimental treatments carry risks of various kinds.
In the case of stem cells, they can be split into mechanical risks, for example from injecting directly through the skull and into the brain, and cellular risks, for example that these cells might become out of control and cancerous.
Here are some stem cell research links on which some of the above was based:
https://www.nature.com/articles/bmt201618
https://www.sciencealert.com/a-blind-woman-has-regained-sight-thanks-to-a-controversial-stem-cell-treatment
https://www.newscientist.com/article/2091841-stem-cell-brain-injections-let-people-walk-again-after-stroke/
https://www.medicalnewstoday.com/articles/294850.php
https://www.sciencedaily.com/releases/2017/01/170110120709.htm
https://www.theguardian.com/science/2009/jan/08/stem-cells-bone-marrow-heart-attack
