What Happened With the STAP Cells Discovery?

In early 2014, researchers in Japan announced the discovery of Stimulus-Triggered Acquisition of Pluripotency, or STAP. The concept involved a simple method for creating powerful stem cells. The core idea was that ordinary cells from an animal’s body could be reprogrammed into a versatile, embryonic-like state by exposing them to environmental stressors. These resulting pluripotent stem cells have the ability to develop into any type of tissue. The proposed technique captured immediate attention for its simplicity and its implications for medicine.

The Sensational Discovery

In January 2014, the journal Nature published two papers from a team led by researcher Haruko Obokata at the RIKEN Center for Developmental Biology. The articles described a procedure for generating pluripotent cells. The method involved taking somatic cells from newborn mice and subjecting them to stress, including bathing them in a mild acid solution for about 30 minutes. This process was reported to revert a cell to an embryonic state, from which it could differentiate into any cell type.

This claim was notable because it proposed an easier path to obtaining valuable cells for biology. Pluripotent stem cells hold promise for regenerative medicine, offering the potential to grow replacement tissues. Before STAP, the standard for creating these cells was a technique for producing induced pluripotent stem cells (iPSCs), which involves inserting genes into a cell’s DNA.

The STAP method appeared to bypass the genetic manipulation required for iPSCs, offering a faster and cheaper alternative. The researchers claimed to have successfully created STAP cells over 200 times. The initial reports suggested these cells could also contribute to placental tissue, something other stem cells could not do, making the discovery seem more significant.

The simplicity of the technique was its most celebrated feature, implying that labs could easily adopt the procedure. If true, STAP would have accelerated research into numerous diseases and injuries. The publications generated immense media coverage, positioning the discovery as a major biological breakthrough.

Unraveling the Claims

Almost immediately after publication, excitement gave way to skepticism. Laboratories across the globe attempted to replicate the STAP cell protocol but were unsuccessful. The inability of independent research groups to reproduce the results was the first major sign of a problem, casting doubt on the original claims.

As replication failures mounted, scientists scrutinized the published data. The conversation moved to online forums like PubPeer, where a crowdsourced effort began to pick apart the two Nature papers. Commentators pointed out numerous anomalies, including images that appeared to have been duplicated or manipulated.

Specific issues included images of supposedly different cell experiments that looked identical. A figure meant to show DNA evidence of pluripotency was found to be a composite of different images. Furthermore, sections of text in the articles were discovered to have been plagiarized from other sources, escalating the controversy.

The scrutiny revealed that some images used to represent STAP cell-derived tissues were similar to images from Obokata’s earlier doctoral thesis. This finding suggested a deliberate effort to misrepresent data. The evidence of flawed data and failed replications created pressure on the authors and institutions to provide an explanation.

The Investigation and Retraction

In response to the controversy, the RIKEN institute launched a formal investigation in February 2014. The committee was tasked with examining the claims of irregularities raised by the scientific community. The inquiry focused on six allegations of research misconduct against Obokata’s team.

The committee released its findings on April 1, 2014, concluding that Obokata was guilty of two instances of scientific misconduct. The first involved fabricating data by reusing an image from her doctoral thesis. The second was the falsification of data by splicing images to create a misleading figure for a DNA analysis.

While the investigation cleared her co-authors of direct misconduct, it criticized them for failing to properly verify the data. Initially, Obokata contested the findings and insisted the STAP phenomenon was real. However, the evidence against the papers and pressure from her co-authors continued to build.

By July 2014, all co-authors had agreed to retract both papers, and Nature officially withdrew the publications. A subsequent attempt by Obokata to produce STAP cells under surveillance at RIKEN also failed. This cemented the conclusion that the original discovery was not valid and marked the end of the STAP cell claim.

Scientific and Personal Aftermath

The fallout from the STAP cell scandal was severe. For the lead author, Haruko Obokata, the consequences were career-ending. She resigned from RIKEN in December 2014 after failing to replicate her results, and her scientific reputation was damaged by the findings of misconduct.

Tragically, Yoshiki Sasai, a distinguished stem cell scientist and a senior co-author, took his own life in August 2014. His death was a shock to the scientific community and highlighted the personal toll that such scandals can take.

The incident also damaged the reputation of the RIKEN institute, one of Japan’s most prestigious research organizations. The scandal exposed weaknesses in its oversight, forcing the institution to undergo restructuring and reform. New guidelines for research ethics and data verification were implemented to prevent a similar event.

For the scientific community, the STAP cell affair served as a cautionary tale. It underscored the importance of reproducibility in the scientific method and demonstrated the effectiveness of post-publication peer review. The case is now used in research ethics to illustrate the pressures that can lead to misconduct and its consequences.