In a January 2011 article describing how estrogen metabolites influence the release of inflammatory molecules from human amnion-derived cells, Italian researchers took advantage of a cell line called WISH, which they describe as “constituting a model for in vitro studies of amnion functions” (1).
There was just one problem: WISH cells have been known for more than 40 years to be highly proliferative HeLa cervical cancer cells. The authors did acknowledge this fact in their conclusions, albeit obliquely and only briefly: “… considering WISH cells as a suitable model for human amnion cells, our results suggest that active estrogen metabolites may finely modulate the onset of human labor. Yet, looking on recent reports, by which WISH cells should be more meaningfully be likened to neoplastic cells, our results could support estrogen metabolite relevance in neoplastic competence via inflammation pathway activation.” (1)
This caveat makes the study's scientific relevance open for debate. According to coauthor Alessandro Dalpiaz, “WISH cells have the advantage of a much longer survival than primary amnion cells in culture. Moreover, they behave mostly as the primary amnion cells. Therefore WISH cells can be considered as a suitable model for human amnion cells to study the effects of inflammation on the modulation of human labor.”
But the fact is, they are not. ATCC, the U.S.-based cell bank from which the authors obtained their cells, lists their origin as “HeLa contaminant.” The line is listed in CellBank Australia's Database of Cross Contaminated or Misidentified Cell Lines, an index of 360-odd lines that are known to be operating under assumed identities. And it was one of 19 contaminated cell lines described in a 1968 letter to Nature by University of Washington geneticist Stanley Gartler, (2) who, as Rebecca Skloot reported in The Immortal Life of Henrietta Lacks, had two years earlier rocked the cell biology community by announcing at a conference that 18 supposedly unique cell lines were all, in fact, HeLa contaminants.
“What really frustrates me is that Stan Gartler showed that a whole series of lines were cross-contaminated with HeLa cells, and yet those bloody cells are still being used now in their false guise,” exclaims John Masters, professor of experimental pathology at University College London. “For nearly 50 years, people have been using falsely identified cells totally unnecessarily because they haven't checked.”
The monetary value of all those wasted experiments—not to mention the resulting patents, drug development, and even clinical trials—is incalculable. In 2007, the BBC alleged that “thousands of studies have been invalidated” and “millions of pounds of charity donations and taxpayers’ money have been wasted on worthless cancer studies” as a result of cell line authentication issues (3). In an open letter that same year to Michael Leavitt, then-secretary of the U.S. Department of Health and Human Services (HHS), professor emeritus Roland Nardone of Catholic University of America attempted to quantitate: “Estimates vary, but as many as 20% of scientific publications using cultured cells may be involved.” (4)
If Nardone, Masters, and others in the cell biology community have their way, such waste will be significantly diminished in the future. Masters and Nardone are members of the ATCC Standards Development Organization Workgroup, which is in the process of formulating standards that can be used in cell line authentication. A final version of the standard (ASN-0002) is anticipated this fall; the main message, says Masters, implores to test early, and often. “It says everyone should use STR [short-tandem repeat] profiling for every cell line they use for every publication and every grant.” At the same time, those stakeholders with the most policy influence— the journals and funding agencies—are slowly enacting rules requiring authors and grant applicants to do just that [see “A Broader Resolution”]. As Nardone's letter succinctly put it, “no authentication, no grant.”
The Source Of Contamination
There are two fundamental types of cell line contamination: infection by microbial agents, and cross-contamination by either inter- or intraspecies cell lines. Rates of all such events are surprisingly high; Hans Drexler, head of the Department of Human and Animal Cell Lines at the German Collection of Microorganisms and Cell Cultures (DSMZ), estimates that 1 cell line for every 6–7 submitted to his cell banking facility is not what it says it is. At CellBank Australia, 11% of samples submitted for testing are contaminated with mycoplasma or other cell lines, according to founding manager Amanda Capes-Davis.