The last decade has witnessed the birth of potentially spectacular tools for human enhancement. Yet to date, they have not been used maximally. The explanation of this requires some background information.
Stem cells are found in embryos, bone marrow, and the umbilical cord. They help the injured body grow new cells. If the body loses blood, it activates stem cells to make new blood. As primordial cells, stem cells can develop into any kind of differentiated cellular tissue: bone, muscle, nerve, and so forth. In theory, they could be directed to form new bones, neural cells, cardiac tissue, and to cure diseases.
For some time, physicians knew that the human body had stem cells, but they had no easy way to grow them, and tediously derived them from minute amounts of tissue from embryos or fetuses. They were called embryonic stem cells.
Then in 1998, John Gearhart of Johns Hopkins University and James Thomson of the University of Wisconsin discovered how to continually produce stem cells—create an immortalized stem cell line. In effect, they discovered how to make human embryos into tiny stem cell factories.
Such commodification of cells bothered critics, who felt that using human embryos for such purposes demeaned the dignity of humans and led down a slippery slope.
Gearhart and Thompson made their discoveries using private funds. As such, the ban at the time on the National Institutes of Health’s (NIH) funding of research involving human embryos meant that NIH could not fund clinical trials with such embryonic stem cells.
At the time, bioconservatives opposed any research with such cells and indirectly helped discover a different kind of stem cell. In 2001, scientists discovered stem cells not only in bone marrow, but also throughout the human body. Called adult stem cells, researchers started using these cells in research rather than using embryonic stem cells. Politically, pundits started to claim that adult stem cells could function just as well as embryonic stem cells.
In the next five years, researchers discovered that many organs and tissues contain precursor cells that act like stem cells. These adult stem cells become specific kinds of cells more quickly than embryonic stem cells.
A director of an institute for regenerative medicine says, “Brain stem cells can make almost all cell types in the brain, and that may be all we need if we want to treat Parkinson’s disease or ALS. Embryonic stem cells might not be necessary in those cases.”[1] Similar, specific adult stem cells can be obtained from the intestine, skin, liver, and bone marrow.
With heart disease, the director of Harvard’s Stem Cell Institute says, “If you could find a progenitor cell in the adult heart that has the ability to replicate, it’s likely easier to start with that than begin with an embryonic stem cell, which has too many options.”[2]
But most adult organs contain few stem cells, not nearly enough to use medically, and adult stem cells are even harder to grow than embryonic stem cells. More fundamentally, “Unlocking the secrets of self-renewal will most likely involve studying embryonic stem cells,” said Harvard’s director.
During the presidency of George W. Bush and under Leon Kass’ Bioethics Council, Congress tried to make it a federal crime to create or use human embryos for medical research. That meant that such embryos could not be turned into embryonic stem cell factories. Sam Brownback (R–KS) led the fight in the Senate for such a bill, but it did not pass.
Backed by the administration of George W. Bush, a similar proposal to ban all forms of cloning worldwide went before the United Nations but failed. Asian countries such as Korea, Malaysia, and China, hoping to excel in biotechnology, aligned with European countries to resist the measure. Malaysia invested $26 million in its BioValley to house one hundred new biotech companies to work on stem cells and raise Malaysia to a world power in biotechnology.[3] China invested in cloning technology, hoping to gain where the West had stumbled.[4]
With Congress stalemated, action about funding research with human embryos fell to states. In passing Proposition 71, California allocated $3 billion for stem cell research from human embryos. State legislatures across the land then battled to fund or to criminalize embryonic cloning. Wisconsin, New Jersey, Connecticut, Illinois, Washington, Ohio, and Maryland funded research while Arizona, Arkansas, Indiana, Michigan, Oklahoma, and North and South Dakota voted to ban research using cloned human embryos.[5]
In 2009, President Barack Obama gave federal regulators new rules for research with embryonic stem cells. The president created a review panel composed of scientists and ethicists to make sure that the couple whose cells were used to create the embryonic stem cells consented to how their embryos were used. Scientists and the American Medical Association liked the results.
Meanwhile, something more momentous had occurred. Again, opposition to use of embryonic stem cells by bioconservatives indirectly motivated it. In 2007, researcher Shinya Yamanaka of Kyoto University discovered how to use four genes to tell skin cells how to revert back to pluripotent cells, called human iPS cells. Thus he learned how to use a few genes to tell a differentiated somatic cell how to revert back to a primordial state and to become an undifferentiated cell that could turn into anything. Now called induced pluripotent stem cells (iPSCs) or more simply, induced stem cells, these powerful cells appear to eliminate the need for human embryos to create embryonic stem cells.
This was a Nobel-Prize–worthy achievement. Yamanaka proved that induced stem cells can be grown without creating human embryos. He thus bypassed the need for research embryos or eggs from female donors.
In 2009, further progress occurred with induced stem cells. Two Chinese teams created identical mice using embryonic stem cells created from induced stem cells created from the skin of the ancestral mice. This achievement was considered the definitive test in proving that iPS cells can truly function as the equivalent of human embryonic cells.
In 2011, researchers reported in Nature Cell Biology that they turned mouse skin cells directly into beating heart cells without the intervening step of creating iPS cells. This is a further stunning advance that leads us to using a person’s own cells to grow as medicine for his ills.
Although this achievement appeared to end, or at least, greatly diminish, the controversy over creating human research embryos, it started others. Such cells might be especially valuable in the new field of regenerative medicine.
Using a person’s own IPS cells might be the greatest therapeutic innovation in the history of medicine. It may be used to treat bodily dysfunctions and perhaps even to improve functions, jumpstarting the new field of regenerative medicine.
The leading edge of such research is in horses and dogs with bone chips, degenerative arthritis, hip dysplasia, and/or spinal cord injuries. Without the ethical hurdles facing human experimentation, regenerative medicine has made real progress in treating old horses and dogs with these diseases.[6] A San Diego company, VetStem, makes cells out of fat collected from these animals and returns concentrations for injection back into the animals. So far, 80 percent of animals are improved, with only 1 percent having bad reactions.
One day soon, the same will be done for humans, especially those with injuries to the spinal cord or degenerative arthritis. Indeed, the success of the therapy in horses and dogs increases the evidence that such a treatment might work in humans. A mammal is a mammal is a mammal.
According to a recent report on 60 Minutes, Dr. Anthony Atala of Wake Forest’s Institute for Regenerative Medicine has successfully taken bladder cells from several patients' bodies, cultivated them in petri dishes, and layered the results in three-dimensional molds that resemble bladders.[7] Within weeks, the molds began functioning as regular bladders, which Atala then implanted back into patients’ bodies. For patients whose ears were severed in accidents, Atala has grown new ears in six to eight weeks and, because the new ears were grown from the patient’s own cells, they were accepted by their bodies. Atala has also grown a human heart valve that beats, originated from human cardiac cells. It will start clinical trials in a few years.
Another leading edge of regenerative medicine is at the University of Pittsburgh, where surgeon Dr. Stephen Badylak directs the McGowan Institute for Regenerative Medicine. Badylak seeks to find the body’s internal signal to turn pluripotent cells into particular types. Using human embryonic stem cells or their equivalents, Badylak wants to replace parts of human bodies the way newts and salamanders do. He’s developed an Extra Cellular Matrix (ECM) that is the platform for replacing various human parts.
We do not yet know how induced stem cells will advance these projects, but they cannot be anything but helpful. For one thing, we don’t need eggs of females to create human embryos or, for that matter, human embryos at all.
Badylak’s most successful project was growing a new esophagus for a patient with esophageal cancer. When surgeons removed the damaged esophagus, they replaced it with an ECM sleeve of the patient’s healthy esophageal cells. Six months later, the patient was cancer-free.
In 2008 at the University of Barcelona, Paolo Macchiarini performed the first tissue engineered trachea transplantation. He took adult stem cells from a patient's bone marrow, grew them into a large population, matured them into cartilage cells, and seeded these with epithileal cells into a purified tracheal segment from a cadaveric donor.
In a promising development, the Australian firm Mesoblast reported “outstanding evidence” that injecting stem cells into the heart of patients with moderate cardiac damage could reduce the risk of further heart attacks by 80 percent.[8] It had similar trials with stem cells in patients with leukemia.
In the military, $250 million goes to fund replacements for burned skin or lost limbs. At the Army’s Institute for Surgical Research, surgeons placed ECMs grown from the tissue of injured vets in traumatic leg wounds and successfully prevented amputation. The ECMs took tissue from the vet’s remaining leg and grew muscle, allowing the veteran to later walk unaided.
At Pittsburgh, similar ECMs allow veterans who have lost hands to have better hand transplants from cadavers. Surgeons transplanted bone marrow from such cadavers to the veterans, and grafted cells from both patient and donor into ECM, successfully performing a hand transplant without the need of life-long use of toxic, immune-suppressing drugs.
Suppose scientists learn how to quickly grow iPSC cells from an athlete and inject them back into his muscles, immune system, bones, and organs. Suppose these injections increased performance and appeared safe. What should we make of this?
First, note that it voids the unnatural objection. What could be more natural than injecting bits of me back into me? Second, it raises the objection that, as an enhancement in sports, it might be impossible to detect. Because they are my cells with my genes and proteins, they will not be rejected by my immune system and will work with my existing organs. By the same facts, no test is going to mark them as different. Unless a test could be developed for higher concentrations of one’s own stem cells or new stem cells in odd places, it would be impossible to prevent such usage in sports.
However, we should not side too much here with Enthusiasm. Caution based on evidence is necessary. James Wilson, whose own research killed Jesse Gelsinger, warns that we should not repeat the errors of gene therapy with stem cells. We should not naively believe we can insert primordial cells into people and that they will instantly morph into helpful cardiac cells. Even if I am injecting my own cells back into me, this could be dangerous. The injection could disrupt my immune system, cause cancer, or even, like the Gelsinger case, kill me. Nothing is ever simple or without risk.
Good science, good facts, and solid evidence must be behind any protocol. However much we want stem cells to be therapeutic, we must first prove them safe in Phase I trials, then test their ability to be therapeutic, and finally test them against existing therapies.
In conclusion, these are exciting developments: ones at the cusp of a new era not only of regenerative medicine, but also of enhancement. The same techniques used to grow my induced stem cells into cardiac cells to repair a damaged heart might be used before my heart is injured to enhance it.
We now need to embrace this new frontier, fund it, and move ahead. This book concludes with some practical proposals for doing so.
Arnold Kriegstein, Director, University of California Institute of Regenerative Medicine, quoted in “What A Bush Veto Would Mean for Stem Cells,” Nancy Gibbs and Alice Park, TIME, July 24, 2006, 36.
Douglas Melton, quoted in “What A Bush Veto Would Mean for Stem Cells,” Nancy Gibbs and Alice Park, TIME, July 24, 2006, 36.
Chee Yoke Heong, “Malaysia’s New Dream: Biovalley,” Asia Times, 2003.
“China, a Cloning Paradise,” Asia Times, February 24, 2005.
“State Cloning Laws,” The National Conference of State Legislators, April 18, 2006.
“Stem Cells for Fido,” Nightline, ABC News, June 24, 2008; “Stem Cell Therapy for Pets,” TIME, July 7, 2008.
“Growing Body Parts,” Morley Safer interview, 60 Minutes, December 14, 2009.
Natasha Khan, “Study: Heart Failure May Be Cut with Stem Cells,” Bloomberg News, December 8, 2011.