Study of available cancer cell lines shows that many are mislabelled or contaminated
Researchers stress how easy and important it is to verify cell lines before use
- Date : 22 Jun 2012
- Topic : Basic science
Modern cancer therapies start in cells – researchers compare cancer samples to healthy cells to discover how cancer is genetically different, and use cell lines to test promising new drugs. However, a University of Colorado Cancer Center study published in the journal Gynecologic Oncology shows that due to a high rate of contamination, misidentification and redundancy in widely available cell lines, researchers may be drawing faulty scientific conclusions.
For example, the cell line known as HES has been widely used as a “normal” model of endometrial cells since its development in 1989. There are literally hundreds of papers that, for example, look for differences between endometrial cancer cells and these supposedly normal HES endometrial cells. Unfortunately, HES is not, in fact, an endometrial cell line. It’s another cell line known as HeLa which was first derived from cervical cancer. If someone makes conclusions about endometrial cancer based on a cervical cancer line, the results are going to be flawed, because it’s not the same genetic pathway. According to Christopher Korch, PhD, investigator at the Colorado Cancer Center and director of the center’s DNA Sequencing and Analysis Service, the paper’s co-first author, there is up to a 40% chance that the cells on the label were not the cells they were actually experimenting on.
Researchers use cell lines to discover genetic features of cancers and to test new drugs
In the past, the technology to check cell lines didn’t exist and so past researchers can’t be really blamed. But today it is cheap, easy and the technology is widely available. The authors of the paper suggest that journals start requiring verification of cell lines as a prerequisite of publishing.
Double-checking if cell lines match the label should be a standard procedure. If a cell line doesn’t match its label, it can call into question perhaps decades of research done using the cells.
While a misidentified cell line seems likely due to a SNAFU on the part of a lab assistant with a faulty filing system, there are more ways than clerical error to end up with the wrong label on a sample of cells.
For example, if two people are working with different cultures in the same hood, or using the same growth medium for the same cultures with the same pipette, HeLa cells can travel in aerosols and once they land where they shouldn’t, they’re so adaptive and aggressive that they tend to out compete other cell lines wherever they land – contamination leads to a quick HeLa takeover and perhaps a vial labelled HES when in fact it’s HeLa.
This work builds on earlier work at the same center by investigators Rebecca Schweppe and Bryan Haugen who found 50% misidentification or contamination in available thyroid cell lines – for example, two were melanoma lines and another was a colon cancer line. The recent research finds the same systemic problems with cell lines of widely varying types.
The authors of the latest paper call when new cells are brought into the lab, it is needed to work meticulously and carefully. They are working to put the group’s data online, both allowing investigators elsewhere to compare their cell lines to the group’s controls, and also to help research groups discover what, if not as labelled, some of the cell lines they tested might be. It is all about building a database large enough to include a match. Until then, they recommend that scientists really need to check their cells. It is just that simple.
Thank you for rating!
You have already rated this page, you can only rate it once!