After Hwang Woo Suk of Seoul National University plunged into ignominy for duplicating images and for other unethical practices in the June 2005 paper on stem cell study in the Science journal, image duplication has been quite regularly spotted in many other studies, particularly in stem cell research.
After a few years of hiatus, instances of image duplications have now come to light. Surprisingly, it is again in the area of stem cell research.
Less than three weeks after two papers on a path-breaking study on reversing adults mice cells into pluripotent cells by using stress — acidic conditions — were published in Nature on January 30, 2014, many scientists across the world have pointed out the use of duplicated images in both the papers. Two instances of image duplication have also been found in the 2011 paper authored by the same researchers.
Also, other scientists have not succeeded in reproducing the results in their labs. According to a news item in Nature , not one of the ten scientists contacted by the journal was able to reproduce the results. Interestingly, Teruhiko Wakayama from Yamanashi University and a coauthor of the paper has not been able to reproduce the results himself despite replicating it prior to publishing the paper.
Reproducibility is one of the criteria to ascertain that a new experiment/procedure reported is indeed valid. Also, the novel procedure has relevance only when it can be reproduced by others in their labs. However, “most of those attempts did not use the same types of cells” as used by the authors of the two papers, notes the news item.
The study was carried out in the Laboratory for Cellular Reprogramming, RIKEN Centre for Developmental Biology, Kobe, Japan and Dr. Haruko Obokata is the lead author of the two papers and also the Corresponding author.
RIKEN centre has already started investigating the study. Nature Group has also started its own investigation. A spokesperson for Nature Publishing Group was quoted as saying that “the matter has been brought to Nature ’s attention and we are investigating.”
Charles Vacanti, an anaesthesiologist at Harvard Medical School in Boston, and the second corresponding author of the latest study had told the journal that the case of image duplication was just a “mix up of some panels.”
He has already requested the journal to carry a correction. “It certainly appears to have been an honest mistake [that] did not affect any of the data, the conclusions or any other component of the paper,” Vacanti was quoted as saying in Nature .
Dr. Wakayama, while admitting that the two images “look similar,” feels that it may be a “case of simple confusion.”
The results of their work were reported in The Hindu on January 30. The authors were able to reprograme adult mice cells to make them pluripotent cells (capable of becoming any of the over 250 specialised cell types) without even using any of the four transcription factors.
But the most important finding was that unlike even embryonic stem cells, the reprogrammed adult cells were able to contribute to both embryonic and placental tissue formation.
Embryonic stem cells can only contribute to the formation of the embryo and not the placental tissue.