A scientist who has been trying to reproduce STAP cells—a new type of stem cells—and has been regularly blogging about his progress has given up. "I don’t think STAP cells exist and it will be a waste of manpower and research funding to carry on with this experiment any further," wrote Kenneth Ka-Ho Lee, an embryologist and stem cell researcher at the Chinese University of Hong Kong, on his ResearchGate page yesterday. Though he is giving up, he hopes others will continue to investigate whether the new approach—which has been dogged by controversy and claims of research misconduct—can really lead to stem cells.
Two papers that appeared online in Nature on 29 January described how subjecting cells from newborn mice to a mildly acidic solution and then tweaking culture conditions turned them into pluripotent stem cells that can differentiate into all of a body's cell types. The authors—Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe, Japan, and colleagues at other institutions in Japan and at Harvard Medical School in Boston—dubbed the process stimulus-triggered acquisition of pluripotency, or STAP.
Whether STAP cells exist is yet to be proven. But the controversy surrounding them shows how scientists are embracing the latest social media tools. Immediately after the Nature papers appeared, stem cell scientist Paul Knoepfler raised questions about STAP cells on his blog. He later started weekly polls, asking how many scientists believed in the existence of STAP cells. He also ran a tally of groups trying to reproduce the results. (So far, none have.) The PubPeer website, for open postpublication review of published papers, set up two webpages—one for each paper. Contributors soon started raising questions about images and text in the Obokata papers.
Lee joined these online efforts on 30 January when he asked if anyone had tried making STAP cells in a post on his page on ResearchGate, a networking site for scientists. ResearchGate operators later asked him to review the papers. He then tried—but failed—to reproduce the results following the methods described in the Nature papers. On 20 March, Charles Vacanti, a senior author of the papers who is an anesthesiologist and tissue engineering researcher at Brigham and Women’s Hospital and Harvard Medical School in Boston, posted his lab’s STAP technique, which involves forcing the mature cells through very small pipettes before exposing them to the acid solution.
Lee took up the challenge and decided to live-blog his efforts. He reported setting up a four-person team, preparing the cells, and making the pipettes, and the process of forcing cells through the pipettes and then subjecting some of them to an acid bath while keeping others as controls. He posted images captured by a confocal microscope. And on 1 April, he reported surprising results. Cells forced through the pipettes showed some expression of genes associated with pluripotency, but not the cells bathed in acid. "I am shocked and amazed" by the results, he wrote. He had to reassure commentators that this was not an April Fools' joke.
In a phone interview, Lee said this put him in a quandary. He thought these unexpected and unusual results needed to be confirmed; but he had also stated he would blog about his progress. He felt bound to share this "little bit of a hint that [the process] might work," he said.
He was suddenly overwhelmed with the attention. Some papers reported that Lee had validated the technique and that he was now in the Vacanti camp. Over the next couple days, he explained that the results had to be validated and that the signals could be byproducts of cell death. Lee wrote that he never claimed that STAP cells exist: "Please, don't hype up this data!" He finally decided to bow out of the race. Despite skepticism about their existence, Lee said he hopes other groups are trying to work with the "glimmer of hope" he found in Vacanti's STAP cells technique.
The live-blogging "was good fun," Lee said in a thick Scottish accent. Though born in and now working in Hong Kong, he grew up in Scotland and still considers that home. He believes the live-blogging was "quite educational for the public" giving a glimpse into the research process. He has also been thrilled by the e-mails he has gotten from budding scientists, including one from a 15-year-old Japanese girl who wanted more details.
He is adamant about getting back to his own work. In his most recent post, he asked, "Anyone want to collaborate with me to look at the function of the BRE gene which is a component of the BRCA1 and BRISC complex?"
Pressed, he admits that he is still curious about STAP cells. But he said that if he gives making them one more try, "I'm not going to live-blog it."