Overview[]
HeLa Cells
On February 8, 1951, Dr. George Otto Gey took cervical cancer cells from Henrietta Lacks, a patient at John Hopkins University Hospital, to isolate and culture them in vitro. Lacks eventually died from cervical cancer in October of the same year, but her cells, named with the first two letters of her first and last name, went on to become the first successful cancer culture propagated in vitro. They also became the longest standing cancer cell line, and the most commonly used human cell culture in the world. Most of the credit for the usefulness and wide-spread of the cell line has been granted to Gey who, after optimizing the culture, objected to its patenting and instead granted use of the tools, processes and the line itself to the whole scientific community.
Since its isolation the line has been used in Nobel worthy experiments (e.g. discovery of telomeric activity), medical scientific breakthroughs (e.g. polio vaccine), and for a long time as a commercial "golden-egg" by John Hopkins University; all of these without the consent or knowledge of Henrietta or her family.
Properties[]
Karyotype of (A) normal cell vs (B) HeLa cell
HeLa cells are "immortal" and proliferate abnormally rapidly, even compared to cancer cells. The cells contain inhibitory proteins PV (papillovirus) E6 and E7; PVE6 causes protein 53, the major regulator of cell cycle, to inactivate, while PV E7 binds to retinoblastoma tumor suppression proteins, inactivating their ability to triger telomeres shortening. The cells have a clear active version of telomerase during cell division, preventing the shortening of telomeres that would lead to eventual apoptosis.
HeLa cells have a remarkable ability to adapt to any tissue culture, and are considered laboratory "weed". Currently, the estimation of in vitro cell lines contaminated with HeLa ranges between 10 and 20%. HeLa cells have 82 chromosomes, with four copies of chromosome 12 and three copies of chromosome 6,8 and 17. Due to its chromosomal incompatibility to human's karyotype and its ability to persist well beyond desired cultivation, Leigh Van Valen was the first scientist to propose it as a new species under the name of Helacyton gartleri.
Research []
By 2010 it was estimated that there were over 60,000 articles containing research done with the HeLa line, ranging from cancer to the effect of toxic substances in human cells. It is estimated that 300 papers citing work with HeLa cells or doing direct research with them are published every month. Here are some of the most cited and explored research with HeLa cells:
HeLa cell mitosis.
1. Polio vaccine by Jonas Salk in 1950s.
2. Test parvo virus, HIV, papillomavirus in human cells.
3. Test of OROV and canine distemper virus, both with properties to induce apoptosis of cells.
4. Studies of sex steroid hormones that can induce cancer such as estradiol, estrogen, estrogen receptors and estrogen like compounds.
5. The discovery of telomere-shortening mechanism by Elizabeth Blackburn.
Controversy and Ethics []
Henrietta Lacks
Henrietta Lacks never gave permission for her cells to be used for research. For decades her family members were unaware of the existence of the cell line, nor had they benefited financially, even though Johns Hopkins had made HeLa cells a commercial line (although it was never patented). It wasn't until 2010, when journalist Rebecca Skloot published her book, "The Immortal Life of Henrietta Lacks", that the scientific community realized that HeLa cells were an example of medical ethical misconduct. The book was hailed for combining the various stories surrounding the HeLa cell line with extensive research into Lacks' life. Read more about the book here .