HeLa cells are ubiquitous in biomedical research — indeed, there have even been reports of HeLa cells contaminating and taking over other cell lines in the lab. By sequencing and transcriptomic analyses, researchers from the European Molecular Biology Laboratory and University Hospital Heidelberg report in G3: Genes, Genomes and Genetics that a number of pathways in HeLa cells "exhibit significantly different expression patterns from those in normal human tissues."
The researchers, led by EMBL's Lars Steinmetz, performed DNA and RNA sequencing of a HeLa Kyoto cell line and examined its mutational profile and gene expression levels, finding about 4.5 million SNVs and half a million indels. The cell line also exhibits an extensive amount of chromosomal rearrangements to the point of chromothripsis, the researchers add. In addition, about 2,000 genes are expressed at a higher level in the HeLa cell line than in normal tissue, and those genes appear to mainly be involved in proliferation, transcription, and DNA repair. "The high expression of some DNA repair genes, some of which also carry potentially damaging NS mutations, suggests that even though HeLa displays high chromosomal instability, specific DNA repair mechanisms may be activated, perhaps irrespective of their effectiveness," the researchers write.
"Our study underscores the importance of accounting for the abnormal characteristics of HeLa cells in experimental design and analysis, and has the potential to refine the use of HeLa cells as a model of human biology," Steinmetz adds in a statement.