The first human became immortal in 1951 in a laboratory in Johns Hopkins Hospital in Baltimore. A cell line was created from a tissue sample from a cancer patient called Henrietta Lacks. These “HeLa” cells have since been used for medical research throughout the whole world. They were used to develop the first polio vaccine in the 1950s and for research into cancer, AIDS, radiation, cloning and genetic mapping. Some 300 scientific papers a month are published about research using HeLa cells. This story is told in the book “The Immortal Life of Henrietta Lacks” by Rebecca Skloot.
Human cells can grow outside the body so long as they are kept in the right conditions. They need a cell culture plate, the right temperature and a mix of nutrients and gasses. Most cells can only divide around 50 times before they die. This is known as the Hayflick limit. It is caused by an accumulation of small errors when replicating the DNA. The key factor is the length of the telomeres at the end of the DNA strand. The more the DNA is copied, the shorter the telomeres get. Cancer cells have an enzyme called telomerase which protects the telomeres. That is what makes cancer cells infinitely replicative. Cancer cells kill you because they are immortal and you are not. One goal of cancer research is to find something to inhibit the telomerase and make them like normal cells which age and die.
Cells get more complicated the closer you look at them. A body has organs like the brain, liver or heart to do specific tasks. Cells have similar subsystems called organelles. The typical parts of an animal cell include a nucleus, mitochondria, a Golgi body, vacuoles, ribosomes and lysosomes. In fact, a cell looks like a complete organism in its own right. A cell respires, digests, excretes and reproduces – all you could wish for in a good husband. There is even a form of cellular memory exhibited in the immune system.
The ‘cell as organism’ proposition should not come as a surprise. Single cell creatures were the only form of life on earth for the first 2 billion years, so they are quite capable of looking after themselves. Multicellular creatures like us evolved from loose colonies of single cell creatures. So a human being can be viewed as the emergent result of a community of 50 trillion cells.
The family of Henrietta Lacks started a law suit to claim financial compensation for the use of the HeLa cells. This is where the catataxis comes in. Is the HeLa cell line still in some way Henrietta Lacks? Did she die in 1951 or is she still alive? If someone is selling vials of your mother’s cells, do they belong to you? The Supreme Court of California says no. Their ruling is that a person’s discarded tissue or cells are not their property and can be commercialised. Tell me what you think…