A prominent Massachusetts Institute of Technology biologist and other researchers have retracted two scientific papers on how breast cancer spreads because the data were improperly patched together from different experiments.
The retraction notices were signed by all authors of both papers, including Robert Weinberg, a cancer biologist and member of the MIT-affiliated Whitehead Institute for Biomedical Research. Weinberg is best known for discovering the first human cancer-causing gene.
"I can tell you unequivocally that the retractions of these papers have no effect on any other research past or present that was conducted in my lab," Weinberg said in an e-mail Thursday. "The work of others in my lab did not draw on any of the results reported in the retracted papers, and the retraction of these papers does not in any way affected the interpretation of the published results of others in my lab."
The two retracted studies, published in the journal Genes & Development in 2009 and 2011, examined how a type of genetic material called a microRNA regulates metastasis — the process by which cancer spreads — in breast cancer.
The retractions, first reported on the blog Retraction Watch, were issued "because original data were compiled from different replicate experiments in order to assemble certain figure panels" in the 2009 paper. The later paper is being withdrawn, the researchers state, because the same analytical method was used.
"We believe that the responsible course of action is to retract the article," the authors wrote in the retraction notice.
Weinberg declined to specify who was responsible for the problem. The lead author, Scott Valastyan, no longer works at MIT and last published a scientific paper in 2012. He did not immediately respond to efforts to reach him.
The retractions occurred shortly after two other issues surfaced in Weinberg's laboratory that also stemmed from problems with assembling or presenting data.
A paper in Cancer Cell was retracted in 2013 because of "errors that were made in the processing/compiling of data figures in this paper," according to the retraction notice. That retraction notice was not signed by one researcher, Yi-Ning Cheng, and the retraction states that the scientists believe the conclusions of the paper are sound despite the problems. The paper had no authors in common with the new retracted paper except for Weinberg.
In 2013, a 2004 paper in Cancer Cell was corrected because of errors in assembling five figures that showed graphs and images of cells, which resulted in "the incorporation of incorrect representative images in these figures." The authors said that study's findings are also upheld.
Both of those studies have been repeated, and when the experiments were redone correctly, the findings were upheld, Weinberg said. One paper was republished with new supporting data.
Nicholas Steneck, director of the research ethics program at the University of Michigan Institute for Clinical and Health Research, said that the retractions do not give enough information to fully understand what went wrong or how the lapses occurred.
"Many prominent lab chiefs do not take an active role in supervising the work of the postdocs. They may have regular meetings with them at which results are presented. They probably do not review manuscripts as carefully as they could," Steneck wrote in an e-mail. "Whether they should is subject to debate."