HeLa: The cells that changed the world
By Caitrin Crudden
Becoming accustomed to science textbooks can lead us into the false idea that scientific discoveries are very ordered and neatly progressive events, yet the truth, which is often left to one side, is the very human nature of scientific discovery and progress. Most science accomplishments or milestones are really a rich story of human desire, dedication, collaboration and, as with every realm where humans are involved, can all too often involve mistakes, corruption and deceit. While there are of course valid reasons to neatly arrange progress stones one by one for our understanding, every once in a while it is worthwhile to explore the true reality of how that stone was discovered and its journey to the great wall of scientific progress.
One such story evolves around the world famous HeLa cells. If you have ever worked in a cell culture laboratory, the chances are you have worked with, or are at least familiar with, the cell line HeLa. HeLa cells were the very first immortalized cell line to be grown in vitro (outside the body), catapulting the cell biology field into progress and very rapidly spreading the world over. Yet HeLa cells have a somewhat more sinister beginning.
HeLa cells belonged to Henrietta Lacks.
And her story deserves to be told.
Henrietta Lacks was a poor black tobacco worker, admitted to the “coloured” wards of John Hopkins Hospital in Baltimore, Maryland in the 1950s. She had an aggressive form of cervical cancer, and was being treated with radium tube inserts, as was standard at the time. One day, prior to starting her scheduled treatment, a doctor took a sample of her cancer cells, without her knowledge, and gave them to a laboratory down the hall aiming to immortalize human cell lines. A cancer researcher named Dr. George Gey at John Hopkins had been trying to grow human cells in his laboratory for decades and every single previous attempt had failed. Dr. Gey had devoted his professional life to trying to optimize conditions in which to grow human cells in the laboratory, knowing how precious this technology would be to the field of cancer biology. If cancer cells could be grown in the lab, they could be studied in a level of detail just not possible within human subjects. To everybody’s astonishment, Henrietta’s cells did not die. They not only survived but grew rapidly in the lab setting, and have not stopped growing since.
Normal cells undergo a finite number of cellular divisions before they die. For a long time, nobody knew how a cell kept count of how many times it had divided or knew when it was time to die, but the reproducibility of the sequences suggested there was some sort of counting mechanism. In 2009 the Nobel Prize in Physiology or Medicine was awarded to Elizabeth Blackburn, Carol Greider and Jack Szostak, for answering this exact question. They discovered that this “cellular clock” is, in part, controlled by elongated ends of chromosomes termed telomeres. Every time a cells genomic DNA is copied for the next set of daughter cells, a very small amount of telomeric DNA is not copied, and therefore these ends get progressively shorter over cellular generations. Once these protective ends have completely run out, true genomic DNA begins to be degraded and this signals to the cell that the time has come to commit “cellular suicide” through apoptosis.
Cancer cells acquire, through the accumulation of genetic mutations, abilities to survive and grow uncontrollably. One survival strategy of cancer cells is to reactivate an embryonic enzyme, telomerase, which keeps adding bits of telomere back on, and in doing so, can render cells immortal. Scientists believe that the aggressive nature of Henrietta’s disease, fuelled by fact that she was positive for both human papillomavirus (HPV) and syphilis, has given rise to this extraordinarily resistant and highly proliferative immortalized cell line.
Although Dr. Gey never aimed to profit from Henrietta’s cells, and sent them to any biomedical researcher that requested them at no charge, their potential did not go unnoticed nor unexploited, and now HeLa cells have been bought and sold by the billions in every corner of the globe. More than 60,000 medical research journal articles have thus far been written using these cells and over 11,000 patent applications involve HeLa cells. Some estimates suggest that somewhere in the region of 50 million tonnes of HeLa cells have been grown. HeLa have been in outer space, in order to determine the effects of outer space on cancer cell growth. In the 1960’s HeLa cells were fused with mouse embryonic cells to create the first cell hybrid, which led on to the process of mapping the human genome. They have been instrumental in vaccine development: Zur Hausen won his Nobel Prize using HeLa cells to create a HPV vaccine. Richard Axel went on to win a Nobel Prize by infecting HeLa cells with HIV. The virologist Jonas Salk used HeLa cells to develop the Salk vaccine which led to the near world-wide eradication of polio. The Nobel prize winning work regarding telomeres, was, you guessed it, carried out on HeLa cells. Their contribution to medical research is astronomical.
The story is soon to be made into a HBO film by Oprah Winfrey and Alan Ball
Henrietta died of her disease nine months after her initial diagnosis, on the 4th October 1951. She was 31 years of age and had five young children. It wasn’t until the 1970’s that Henrietta’s family had any idea of her contribution, when they were contacted by researchers hoping to explore in greater detail HeLa’s genetics. Although her family have since learned of their mother’s/grandmother’s unwitting contribution to the world, they struggle with this legacy and the damningly unfair bioethics and legalities that surround it. Despite the fact that one small vial of HeLa cells is now sold for around 4,000 SEK, and have been profited upon for decades, Henrietta’s family live in poverty in Baltimore and to this day cannot afford health insurance. It took 60 years before Henrietta‘s grave could be given a headstone.
The surreal complexity of some biological entities such as subcellular signaling networks can seem almost extraterrestrial in nature, and so abstraction from the human element can become commonplace. Once in a while, we as scientists can become so engrossed in the detail that we can forget how or why we got here. The story of Henrietta Lacks gave the world so much, not simply in cell biology and medical progress, but in the development of the field of bioethics, moral experimentation and the questions surrounding ownership of one’s own body, constituents of which now can survive long after death. Cases such as Henrietta’s, and the infamous Tuskegee syphilis trial in which African-American men were unknowing research subjects in the study of the progression of untreated syphilis, that continued long after a treatment was found, led to the development of laws such as informed consent, diagnosis communication and clinical trial standards which upheld the protection of human research subjects. As scientists, it is imperative for us to bear in mind that although human help is most often our end point goal, it is not a distant issue. Real human beings are behind almost every biological sample we work with; these are not infinite inanimate tools, and our work often depends on the generosity of human samples and participation. The people behind these entities have hopes, desires and a dignity that needs to be upheld.
For those interested there is a great book “The Immortal life of Henrietta Lacks” by Rebecca Skloot, and the story is soon to be made into a HBO film by Oprah Winfrey and Alan Ball.