24 April 2013
In 1951, Henrietta Lacks was diagnosed with cervical cancer. She had an aggressive tumour that quickly took over her body. Less than a year after being diagnosed, she died; leaving behind a devastated husband and 6 children. She was 31 years old. But even in her death, some of her cells lived on; dividing and growing, making trillions more cells than ever existed in her body. The combined weight of these cells is now over 400 times what Henrietta Lacks weighed when she was alive.
They have been used to test the effects of nuclear radiation, to develop the polio vaccine, been sent into space, for chemotherapy and cloning, and to study diseases like cancer; saving tens of thousands of lives, and still continue to divide relentlessly in plastic dishes in laboratories all over the world. These cells are famous under a new name: HeLa.
Before the 1950’s, trying to understand and cure diseases like cancer, scientists were limited to testing new drugs or treatments that could be harmful or extremely toxic on patients. As an alternative, scientists were trying to grow cells outside of the human body and use these as the test subjects, in a technique known as tissue culture.
The problem was that cells don’t survive well when separated from a human body. They depend on the oxygen and nutrients the body constantly supplies. Cells also have a tightly controlled life cycle. They grow, divide and die and each step is monitored very carefully by the nucleus, the ‘brain’ of the cell that stores the DNA. Scientists were trying to overcome these problems by using cancer cells from tumours, growing them in special soups that supplied the nutrients that cells needed.
Cancer cells are different from normal human cells in that a single mutation in their DNA causes them to go haywire. Their rhythmic life cycle spins out of control, making cells that misbehave. Instead of growing and working as they should, they group together forming tumours that start spreading all over the body – and, if they get the nutrients they need, they don’t die. Because of their immortality, the scientists thought that cancer cells would be the ideal cells to use.
One of the pioneers of tissue culture was George Gey, who had a research lab at Johns Hopkins Hospital in Baltimore, USA. He was trying to get cells from different tumours to survive in dishes, growing in nutrient soups. Like Groote Schuur and Tygerberg Hospitals in Cape Town or Chris Hani Baragwanath Hospital in Johannesburg, Johns Hopkins is a teaching hospital that not only treats people but also trains future doctors and researchers, who have access to patients as part of their training. So Gey had a continuous supply of tumours that doctors would collect from patients.
When Henrietta Lacks went in to Johns Hopkins Hospital to get treatment for her cancer, without her knowledge, her doctor scraped out a small piece of her tumour, about the size of a 20c coin, and a piece of the healthy tissue near it to give to George Gey.
Gey’s lab assistant, Mary Kubicek put the tumour cells into a dish with a nutrient soup, labelling them HeLa, taking the first two letters from Henrietta’s name and surname. Over the next few weeks, she watched the tumour cells grow and divide and spread from one dish to another, faster than any other cells they’d tried before and far outliving Henrietta’s normal cells, which died a few days after being put in a dish. Since then, HeLa cells have carried on growing and dividing. They are resilient and hardy. They can travel on dust particles and have been known to land in dishes with other cells and slowly take over, competing with these cells for nutrients.
Because cancer cells multiply faster than normal cells, mistakes creep in, which means that if you were to compare the DNA from tumour cells taken from Henrietta Lacks in 1951 to a HeLa cell growing in a lab today, you would see that the DNA will be slightly different.
No one is sure why HeLa cells grow so wildly and so well. We do know that the mutation that triggered Henrietta’s cancer was from extra DNA from the human papillomavirus (HPV) that inserted itself into the DNA of Henrietta’s cervical cells. We now know that HPV infection causes cervical cancer in women, thanks in part to research done using HeLa cells.
Despite the key part HeLa cells have played in science and medicine, Henrietta and her family knew nothing about it. At the time, there were no laws requiring patient consent for treatment or testing new medications. Doctors were under no legal obligation to ask permission or explain what they intended to do to patients and could also take samples, like blood, tissue or skin for testing. Now, there are laws to protect patients enrolling in clinical trials to test new drugs. But the laws to say what happens to samples that are taken from patients are still not clear. Most of the research that has used HeLa cells is non-profit, but some organisations have developed a multi-million dollar industry selling HeLa cells.
Meanwhile, after her death, Henrietta Lacks’ family struggled in poverty, not knowing that a part of their mother lived on and what a huge influence HeLa was to have on medicine. They discovered the truth quite by accident, and the debate about what rights they have to their mother’s unique legacy rages on.
This was brought home in March when the HeLa cell genome—the entire set of DNA in the cell— was published online, freely accessible to anyone. This again raised the question what the rights were when it comes to ownership of genetic information. Do scientists have a right to make information available that could possibly allow anyone to work out medical information on the Lacks’ family? The European Molecular Biology Laboratory that published the genome stated that the HeLa cells have mutated to such an extent and because they were taken from Henrietta Lacks’ cancer, you wouldn’t be able to tell much about her descendants. They have, however, now removed the information about the genome from their website.
The remarkable story of a women who was lost to the world as Henrietta Lacks but ‘lives’ on as HeLa is a reminder that we need to keep the lines of communication open between patient and doctor, researcher and society.
If you would like to know more about Henrietta Lacks, her family or the story of how her cells have changed the world, read Rebecca Skloot’s book The Immortal Life of Henrietta Lacks