HEK 293 cells (Human embryonic kidney 293 cells) were originally cultured by Frank Graham in 1953 and have since gone on to become one of the most widely used cell line research models after HeLa and CHO cells.
HEK 293 cells were derived from cultures of human embryonic kidney tissues and transfected with adenovirus 5 DNA. This allowed use of this viral promotor to allow an increase transcription of products such as recombinant proteins. There are now a number of HEK 293 variants which have been produced for specific applications. Some of the differences could easily be missed, so it is important to ensure the appropriate HEK 293 cell line variant is being used. A further point of interest is that HEK 293 cells cannot be used as a model to describe normal kidney cells since it was found that these cells express neuronal genes which would link them to being sourced from embryonic kidney tissue rather than adult kidney cells (thence the name HEK). Despite these caveats, these cells are still highly applicable to biotechnology applications since they are easy to work with being robust, grow quickly and easy to transfect.
HEK 293 cells are commonly used to produce therapeutic proteins and viruses. HEK 293T is an example of a derivative of the parental HEK 293 cell line which has been optimised for these applications. In this case, HEK 293 cells were transfected to stably express a large, temperature sensitive “T-antigen” containing an SV40 (virus) origin of expression (and a Neomycin resistance gene). What this means is that any transfected plasmids which have the SV40 origin of replication can be expressed to a high level. Larger amounts of protein or virus can therefore be produced compared to the HEK 293 cells without the additional promotor system.
What are the applications of HEK 293 cells?
Studying intracellular calcium ions (Ca2+) 1,2
Protein interactions and studies 3
Gene expression 4, 5
References and Further Reading
Electron-multiplying charge-coupled detector-based bioluminescence recording of single-cell Ca2+, K. L. Rogers, J-M. Martin, O. Renaud, E. Karplus, M-A. Nicola, M. Nguyen, S. Picaud, S. L. Shorte and P. Brulet, J. of Biomedical Optics, 13(3), 031211 (2008). https://doi.org/10.1117/1.2937236
Red fluorescent genetically encoded Ca2+ indicators for use in mitochondria and endoplasmic reticulum, J. Wu, D. L. Prole, Y. Shen, Z. Lin, A. Gnanasekaran, Y. Liu, L. Chen, H. Zhou, S. R. W. Chen, Y. M. Usachev, C. W. Taylor and R. E. Campbell, Biochem J, 2014, 464, 1, 13-22, https://doi.org/10.1042/BJ20140931
Improved split fluorescent proteins for endogenous protein labelling, S. Feng, S. Sekine, V. Pessino, H. Li, M. D. Leonetti and B. Huang, Nature Communications, 8, 370, https://doi.org/10.1038/s41467-017-00494-8
Simian virus 40 replication in adenovirus-transformed human cells antagonizes gene expression, J. S. Lebkowski, S. Clancy and M. P. Calos, 1985, Nature, 317, 169–171, https://doi.org/10.1038/317169a0
Transient Gene Expression in Suspension HEK‐293 Cells: Application to Large‐Scale Protein Production, L. Baldi, N. Muller, S. Picasso, R. Jacquet, P. Girard, H, P, Thanh, E, Derow and F, M. Wurm, 2008, Biotechnology progress, 21, 1, 148-153, https://doi.org/10.1021/bp049830x