It was an unhappy Christmas for stem cell researchers. The field seemed to implode when South Korean scientist Woo Suk Hwang retracted a landmark paper published last June in the journal Science. Its key claims have been shown to be false, and Hwang has been accused of fabricating data. Although he denies the charge, this is shaping up to be the most significant case of scientific misconduct in years.
Hwang's research had seemed to establish the feasibility of the holy grail of stem cell research: to produce stem cells cloned from the tissues of patients. Stem cells, generated in the initial stages of growth of an embryo, are "pluripotent": capable of developing into any kind of tissue. If such cell lines could be cultured, they might be used to treat neurodegenerative diseases such as Alzheimer's or to replace a faulty pancreas or kidney. Cloned stem cells would share the DNA of the individuals from whom they were derived.
Hwang and his colleagues claimed to have transferred DNA from patients' cells into the eggs of unrelated women to create embryonic balls of cells called blastocysts. The team said they then extracted stem cell lines from these embryos, matched to the respective DNA donors.
Hwang seemed to be leaps and bounds ahead of the pack in this competitive field, and in South Korea his achievements made him a national hero. A rags-to-riches genius, he received £23m in grant money, was featured on Korean stamps and looked set for a Nobel prize. His fall from grace has been received in South Korea as a blow to the nation's pride.
Hwang's problems began last November when co-authors of his breakthrough paper expressed ethical concerns that some of the eggs in the study came from junior members of his team, and others from paid donors. Hwang at first denied the charge, but later shamefacedly owned up. Korean reporters have now claimed that the donors from his own lab contributed eggs only under pressure.
Worse followed. In November, Gerald Schatten of the University of Pittsburgh, previously the Korean group's champion in the west, asked for his name to be removed from the Science paper after receiving information from one of Hwang's team that appeared to throw the results into question. Then two of Hwang's Korean collaborators alleged that some of the data was falsified. An investigation by Seoul National University, where Hwang is based, concluded that errors in the paper, which Hwang had previously admitted but ascribed to "human error," could on the contrary "only be seen as a deliberate fabrication."
The scandal has delighted opponents of stem cell research in the US, who argue that it shows the field is unethical and over-hyped. And it raises questions over peer review, although journal editors rightly point out that both they and their referees have little choice but to take submitted data on trust. Deliberate falsification is hard to spot.
But how badly does the Hwang affair set back the science? Stem cell researchers have to accept that, as far as cloning of human cells is concerned, they are again at square one. Yet the picture is not as bleak as some have suggested. In January 2006, two US teams reported developments that could obviate the ethical concerns responsible for very tight constraints on stem cell research there and in some other countries. The principle objection is that harvesting stem cells from human blastocysts involves destruction of the embryos. Now researchers at MIT have cloned, and extracted stem cells from, blastocysts modified so that they fundamentally lack the capacity to become foetuses, and thus cannot be seen as "potential organisms." And a team at Massachusetts-based Advanced Cell Technology has taken the opposite route by developing a method for extracting stem cells from blastocysts without impairing their subsequent capacity to develop into foetuses.
Both studies were conducted in mice, however, and the question that now seems as open as ever is whether the same is possible in humans.
The satellite navigation wars
With the launch of the first of the European Space Agency's Galileo satellites in December, satellite navigation will soon no longer be reliant on the Global Positioning System (GPS)—and therefore no longer in the hands of the US military. The Pentagon can scramble GPS signals at will, but Galileo—which will ultimately consist of 30 satellites, and should be fully operational by 2008—is strictly a civilian-run affair. The Pentagon has complained that its signals could interfere with GPS, but its main worry is more probably that China, as one of ESA's partners in the project, has access to Galileo's guidance.
Keep your p11 up
If you're feeling down, blame the p11. Low levels of this protein have been implicated in depression. Apparently it helps to activate the neuroreceptors that bind to serotonin, the brain's "feelgood" neurotransmitter. Among the factors that could depress production of p11 are stress-induced hormones, while antidepressant drugs seem to boost p11 levels. This sounds like good news for treating depression. But it's also a reminder of the deceptive allure of gene-based medicine, for the p11 gene joins a long list of genes known to affect the behaviour of serotonin: there's no one-strike solution to this form of depression.
