Thursday, July 2, 2015

Predictably Unpredictable

Predictions about science can be, well, unpredictable.

A recent posting on the science/technology website Gizmodo nicely makes the point.

The author reviews a year-end issue of Scientific American from 10 years ago, December 2005, identifying the top 50 scientific trends of the year and where those trends might lead. The author was interested to see how accurate the magazine’s predictions turned out to be 10 years later.

On any number of the predictions, the actual outcomes either fell far short or have not been fulfilled at all.  Science can be predictably unpredictable.

But for purposes of this blog, one prediction stands out. Topping the list of 50 leading scientific trends for 2005 was: “Patient-specific stem cells that pave the way for stem cell therapy.”

Such a prediction was typical at that time, fueled by the dramatic announcement in March 2004 that South Korean researcher Woo Suk Hwang had succeeded in using somatic cell nuclear transfer (SCNT) to create cloned human embryos. The goal was to use these embryos to harvest stem cells genetically matched to the original donor of the somatic cell used in the SCNT cloning process. Hwang published a second paper in 2005, confirming his initial success while claiming improved efficiency in the cloning process.

Hwang’s claim to be the first to create human embryos by cloning garnered international attention and vaulted him into the top tier of scientific researchers.

This was because cloning was seen as the essential step to realizing the promise of embryonic stem cells. Since 1998, when University of Wisconsin researcher James Thomson first isolated human embryonic stem cells (hESCs) from so-called “leftover” IVF embryos, they were hyped as the potential cure for all manner of diseases and conditions. The drawback was that these stem cells would be subject to tissue rejection if injected into a patient. Cloning appeared to offer a solution to this problem, since the patient’s body would not reject its own cells. So cloning, in turn, was hyped as the key to the future of regenerative medicine.

For example, at a February 2002 hearing before the Senate Judiciary Committee, participants, both Senators and witnesses from the scientific community hailed human cloning as key to the future advance of medicine. As Sen. Dianne Feinstein said in her opening remarks: “Many doctors and scientists have argued that we must protect our ability to use cloning techniques to try to save and improve the lives of those ravaged by disease and other ailments. In fact, nuclear transplantation offers enormous potential for pro-viding cures to diseases such as cancer, diabetes, cystic fibrosis, and heart disease, as well as conditions such as spinal cord injuries, liver damage, arthritis, and burns… and many other potential cures and treatments for a variety of diseases and ailments.”

Other participants spoke of SCNT’s “very real promise” and “considerable potential for developing new medical therapies for life-threatening diseases,” and of how “essential” human cloning research was to the future of medicine. 

In The Scientific Conquest of Death (Libros en Red, 2004), leading cloning proponent Dr. Michael West, claimed that cloning offered healing powers of literally biblical proportions.  In his essay “Therapeutic Cloning,” West wrote: “We have been given two talents of gold. The first, the root of immortal human life, is the human embryonic stem cell. The second is nuclear transfer technology. Shall we, like the good steward of the Bible, take these gifts to mankind and courageously use them to the best of our abilities to alleviate the suffering of our fellow human beings, or will we fail most miserably and bury these gifts in the earth?”

On August 1, 2001, West had testified to a Senate subcommittee to similar effect: “On the scientific front, I think it's useful to point out that mankind occasionally is given gifts, things that can greatly advance the human condition. I think we've been given two in just recent history. The first, as we've talked about at some length already this morning, is the human embryonic stem cell. … A second gift we've been given is this miracle we call cloning, or nuclear transfer.”

Yet contrary to predictions by Scientific American as well as Pelosi, West and others, Hwang’s research and SCNT did not pave the way to stem cell therapies. 

Why? As the Gizmodo blog points, the prediction was based on a “breakthrough that turned out to be one of the biggest cases of scientific fraud ever.”

Towards the end of 2005, the credibility of Hwang’s research findings came under intense scrutiny. His claim to be the first to successfully clone human embryos and derive stem cells from them was revealed to be completely fraudulent.  By January 2006, Science had retracted both of Hwang’s papers. It seemed the hype in favor of cloning was so great that it encouraged him to exaggerate and even fabricate results. Yet the Scientific American prediction that “patient specific stem cells” would pave the way for stem cell therapies was not entirely wrong. In fact, that prediction is coming true -- but not the way proponents of cloning predicted.

The prediction is becoming reality because of ethically non-controversial research that does not rely on human cloning or the destruction of human embryos.

In 2007, Japanese scientist Shinya Yamanaka developed a method to take an ordinary somatic cell – the same type of cell used for human cloning -- and coax (i.e., induce) that cell to a fully pluripotent state, so that it has many of the properties of an embryonic strem cell. He was able to do this without destroying embryos or obtaining eggs for use in cloning. Such cells are an exact genetic match to the person the body cell was obtained from.   

Since Yamanaka’s original breakthrough discovery, scientists have refined and improved the technique for producing these “induced pluripotent stem cells” (iPSCs). Dr. Yamanaka himself has won the Nobel Prize for this scientific and medical advance. And iPSCs are helping to realize the “vast potential” of stem cells for therapeutic benefits – a potential once wrongly claimed for human cloning.

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