The year 1951 brought about a significant and unforgettable breakthrough in medical research- the birth of HeLa cells, the first and most well-known human immortal cell line. The HeLa cell line was generated in Johns Hopkins Hospital lab, by a scientist called George Gey, and was derived from a cervical tissue sample taken from an African American woman named Henrietta Lacks during a medical procedure following her cervical carcinoma diagnosis shortly after giving birth to her fifth child. It was the first successful culture after countless failed attempts and served, at the time, as an invaluable tool in the fight for discovering the nature of and cure for cancer to save many lives. Then, not long after, her cells paved the way for further breakthroughs in various other fields, including cancer, such as immunology, epidemiology and genetics. This article will explore a couple of the uses, historical and topical, of HeLa cells as well as the controversy that raged surrounding them and the subsequent reforms in policies regarding scientific research.
How are they immortal?
HeLa cells behave differently to normal cells. In fact, during the original lab culture, the HeLa cells grew 20 times faster than Henrietta’s normal cells. HeLa cells have many distinct characteristics, as cancerous cells formed from a genetic mutation, that make them immortal with the ability to continuously divide. Years after her death, research into HeLa cells revealed that cancer cells, including HeLa cells, contained an active form of the enzyme called telomerase which would partly explain the mechanism behind cell immortality. Telomerase gives the cells the means to overcome the Hayflick Limit in which normal cells are restricted to undergoing only a limited number, about 50, of cell divisions before death. Telomerase does this by preventing the gradual shortening of chromosome ends called telomere, which is attributed to cell ageing and cellular senescence, to prevent the degradation and death of chromosomes and consequently allow indefinite cell division and proliferation, given warm conditions and an appropriate culture medium. This immortality enabled HeLa cells to be mass produced and distributed to then equip scientists around the world with the scope to research and investigate many aspects of human life and disease. The uninhibited growth also, however, gave rise to the problem of contamination of other cell lines which has hindered research using those cell lines.
Vaccine development
The use of HeLa cells in medical research has revolutionised the way we control and treat infectious diseases. One way in particular is through their contribution to life-saving vaccine development.
HPV
An analysis of HeLa cells in 1984 by a German virologist revealed the presence of several copies of Human Papilloma Virus 18 (HPV-18), a sexually transmitted virus strain. This virus strain was believed to be what caused Lacks’ cervical cancer. Scientist then used the understanding of the interactions the HPV virus has with HeLa cells on a genetic level to develop the lifesaving HPV vaccine that today has the potential to nearly eliminate cervical cancer. However, it wasn’t until the genome sequencing of HeLa cells that the details of Lacks’ cancer were uncovered with the findings suggesting that the virus did this by generating a mutation on chromosome 11 to suppress a particular tumour suppressor gene.
Poliovirus
HeLa cells have also made a critical contribution to the development of the Polio vaccine, another significant vaccine. The Polio vaccine provides protection from Poliomyelitis, a disease with causes nerve damage and can lead to partial for full paralysis and a disease which became an epidemic for the world in 1951 leaving 21,000 people paralysed. From the early 1950s, through mass production of HeLa cells, scientists were able to produce an effective polio vaccine. As HeLa cells were readily available and are easily susceptible to poliovirus infection, one researcher, Jonas Salk, used the cells to infect them with poliovirus during a trial to test the vaccine efficacy and safety on a large scale to then mass-produce his polio vaccine.
Covid-19
A more recent application of HeLa cells has been during the current pandemic in the urgent research, development and approval of safe and effective vaccines for protection against Covid-19 to achieve herd immunity. There are about 125 potential vaccines against Covid-19 that can be classified into many categories. Some, during their development, do not involve live cells, and so no cell line, like RNA vaccines; other kinds require cell lines, such as the HeLa cell line, like traditional vaccines that entail the process of attenuation where the virus goes through its life cycle, in replicating and infecting a cell line, to gradually lose its potency to then be used in vaccines.
Covid-19 research has used many different immortalised cell lines to study different aspects and properties of the novel coronavirus. Using HeLa cells to study the virus, how it replicates and how it interacts with human cells is helping scientists gain greater understandings of the nature of coronavirus so that professionals are better equipped to potentially develop other treatments. For example, HeLa cells have been used to understand the infectivity of the virus. Researchers discovered that HeLa cells were not easily infected by Covid-19 and this discovery prompted researchers to search for the “key” that HeLa cells did not have, that other cells did, to enable entry of the virus into the cell. They then discovered this to be the molecule ACE 2 which surrounds the surface of cells that are susceptible to covid infection.
All the information we can extract about Covid-19 interaction with human cells has a vital role to play in allowing for the communication of accurate and evidence-based information and advice for the public as well as an effective vaccine programme.
Other uses
In addition to uses of HeLa cells to further research in the fields of virology and immunology, they have had other remarkable uses such as in research to study other types of cancers and how they respond to various cancer drug candidates, in in-vitro fertilisation, in one of the earliest space missions to investigate the effects of zero gravity on cells, genetics, how cells react to certain chemicals, the effects of radiation and many more. HeLa cells are highly sought after for research and there are more than 60,000 medical publications regarding their use.
The controversy
The story of Henrietta Lacks draws attention to many ethical issues and has sparked discussion since which has, in part, contributed to policy changes in healthcare regarding the use and distribution of human tissues and medical information in research.
Samples of her cancerous cells were taken during her cancer treatment and given to a researcher in Johns Hopkins Lab who used them to create the first ever immortal cell line. They were then distributed to many other researchers around the world as their ability to facilitate research was promising. However, this was done without her or family’s knowledge or consent and the basis of the ethical controversy centres around this reality.
Henrietta Lacks and her family did not know about the collection and distribution; it took 22 years after Henrietta Lacks death for her family to be informed of the extent of distribution and application of her cells and the multimillion-dollar industry that developed through the production and use of her cells. Also, her medical records had been released, without the permission of her family, to a reporter to publish a book containing such private information that anyone could read when none of Henrietta Lacks’ relative has even seen her records. Furthermore, the HeLa genome was published in 2013 without consent from her family which might have disclosed sensitive genetic information about the Lacks family. Nevertheless, by the standards and ideals observed at the time, the taking and use of her or anyone’s cells without informed consent was not deemed unethical as informed consent was simply not commonly practiced as it is today; the happening may have not been considered to be fuelled with bad intentions but they were much less mindful of the importance of informed consent and confidentiality.
Today we have stricter laws and policies in place to ensure patients are informed and to protect their medical privacy. The 2004 Human Tissue Act sets out clear guidelines and regulations surrounding the “removal, storage, use and disposal of human bodies, organs and tissue”. It means that researchers are required to take proper and informed consent from patients before taking from them samples of their tissues for research purposes. However, there are exceptions: researchers are not legally required to obtain consent if samples are taken for diagnostic purposes and patient identifiable information has been omitted but these researchers have to have provision and have to be authorised with licences. This is similar to what’s imposed by National Institution of Health in the US federal law. In addition, patients’ data is kept safe and its use is well-regulated and with controlled access to ensure it is used for intended purposes and in proper hands. All these conditions ensure that medical data and human tissues are employed in a safe and ethical manner and ensures people can practice their autonomy properly which, in turn, builds the confidence of clinicians and the public in research.
Overall, HeLa cells contributed to significant breakthroughs in biomedical research, from better understanding cancer and the mechanisms by which viruses infect our cells for drug and vaccine development to discovering the impacts of the environment on human cells. The immortality of HeLa cells, has proved to be a key asset to research and this knowledge has led scientists to discover ways to induce such immortality in normal cells. Considerations of the origins of the HeLa cell line has brought about a more conscious effort to protect patients’ autonomy and confidentiality in research. Although the Lacks family haven’t received financial compensation, they are now having their best interests acknowledged when it comes to any future applications of HeLa cells, with negotiations with the Lacks family having taken place to approve such research.
References
2018. How HeLa cell works. [image] Available at: <https://www.bing.com/videos/search?q=what+are+hela+cells&&view=detail&mid=D9546D37EC9A5CB98565D9546D37EC9A5CB98565&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dwhat%2Bare%2Bhela%2Bcells%26FORM%3DVDVVXX> [Accessed 9 July 2021].
2019. Henrietta Lacks’ ‘Immortal’ Cells. [image] Available at: <https://www.bing.com/videos/search?q=what+are+hela+cells&ru=%2fvideos%2fsearch%3fq%3dwhat%2bare%2bhela%2bcells%26FORM%3dHDRSC3&view=detail&mid=D0DCCCA17CB95EFF961DD0DCCCA17CB95EFF961D&rvsmid=B6DB93A88B766F01148EB6DB93A88B766F01148E&FORM=VDMCNR> [Accessed 9 July 2021].
2020. [online] Available at: <https://www.washingtonpost.com/history/2020/04/14/cutter-polio-vaccine-paralyzed-children-coronavirus/> [Accessed 9 July 2021].
2020. HeLa Cells Speech. [image] Available at: <https://www.bing.com/videos/search?q=what+are+hela+cells&&view=detail&mid=A0D87CB073F4E4560B49A0D87CB073F4E4560B49&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dwhat%2Bare%2Bhela%2Bcells%26FORM%3DVDVVXX> [Accessed 9 July 2021].
Bbc.co.uk. n.d. [online] Available at: <https://www.bbc.co.uk/bitesize/articles/zv6cydm> [Accessed 9 July 2021].
Callaway, E., 2013. Most popular human cell in science gets sequenced. Nature,.
En.wikipedia.org. 2021. Cellular senescence - Wikipedia. [online] Available at: <https://en.wikipedia.org/wiki/Cellular_senescence#:~:text=Cellular%20senescence%20is%20a%20phenomenon%20characterized%20by%20the,approximately%2050%20cell%20population%20doublings%20before%20becoming%20senescent.> [Accessed 9 July 2021].
Hindustan Times. 2020. Henrietta Lacks and her contribution to Covid-19 vaccine. [online] Available at: <https://www.hindustantimes.com/world-news/who-is-henrietta-lacks-and-what-s-her-connection-to-the-covid-19-vaccine/story-neC7CB4lUabGiFgJVbbp2L.html> [Accessed 9 July 2021].
Human Tissue Rights: Will They Slow Advancement?. n.d. Henrietta Lacks. [online] Available at: <https://mayihaveyourtissues.weebly.com/henrietta-lacks.html> [Accessed 9 July 2021].
n.d. [online] Available at: <https://www.microscopemaster.com/hela-cells.html> [Accessed 9 July 2021].
n.d. [online] Available at: <https://www.enotes.com/homework-help/how-did-lacks-family-find-out-that-people-were-478271> [Accessed 9 July 2021].
Nature, 2020. Henrietta Lacks: science must right a historical wrong. 585(7823), pp.7-7.
Science in the News. 2020. Vessels for Collective Progress: the use of HeLa cells in COVID-19 research - Science in the News. [online] Available at: <https://sitn.hms.harvard.edu/flash/2020/vessels-for-collective-progress-the-use-of-hela-cells-in-covid-19-research/> [Accessed 9 July 2021].
Skloot, R., n.d. The immortal life of Henrietta Lacks.
stillunfold.com. 2017. What Are Immortal Cells (HeLa Cells) & Why Are They Important?. [online] Available at: <https://stillunfold.com/science/what-are-immortal-cells-hela-cells-why-are-they-important> [Accessed 9 July 2021].
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