One young black woman has a reasonable claim to have made one of the greatest contributions to modern medicine — without ever knowing she had.
Henrietta Lacks was diagnosed with cervical cancer in 1951 at the age of just 31, shortly after giving birth to her fifth child. At the time, many hospitals in the US still segregated black people from white people, so there were few options for her to seek treatment when she started suffering symptoms. She turned to Johns Hopkins Hospital in Baltimore, Maryland, as it was the nearest to her home.
The ward she ended up in happened to be down the hall from George Gey, a researcher who had been trying to grow human cells in his lab for decades. During the treatment to remove her tumour, her doctor sent a small sample of tissue without her consent to Gey. Up to this point, attempts to grow human cells outside the body had been failures. But something about Lacks’s cells was about to change that.
In most people a natural process called senescence puts a limit on the lifespan of cells. Senescence is linked to aging: as cells divide and multiply over time, the accuracy of each accompanying replication of DNA wanes. The protective caps on the end of each strand of DNA — known as telomeres — shorten, until eventually the DNA strands are unprotected and harmful mutations arise. These mutations tend to be associated with cancers and other age-related diseases. To protect against this, the replication machinery inside cells is able to detect this shortening of the telomeres so that after a certain point they stop dividing.
Typically human cells are able to divide around 50 times before they reach senescence.
But Lacks’s cells were different. Her cells were able to divide and replicate indefinitely. It made them perfect for medical research as a culture of identical cells could be grown quickly. Soon, scientists all over the world were taking shipments of Lacks’s cells for their research.
Her cell line, which came to be known as “HeLa” in honour of Lacks, is the first and most commonly used immortalised cell line in medicine. Millions of people owe their lives to the tissue taken from her — the cell line it generated was used to create the first polio vaccine, cancer medicines and in vitro fertilisation. Her cells even made it into space before any living human. (Read more about other controversial cells that have saved millions of lives.)
Her story is also one of complicated ethics. In 1951 the idea of informed consent was uncommon, so her family had no idea of Lacks’s contributions until journalist Rebecca Skloot traced back her DNA 50 years later. In the video above BBC Reel speaks to Lacks’s descendents about her enormous legacy and the moment they found out about Lacks’s contribution to all of our lives.