HeLa is a cell type in an immortal cell line used in scientific research. It is the oldest and most commonly used human cell line. Its scientific name is Helacyton gartleri. It came from cervical cancer cells taken on February 8, 1951 from Henrietta lacks who died of her cancer on October 4, 1951.
Henrietta’s cells were the first immortal human cells ever grown in culture. HeLa cells are called immortal because they can divide an unlimited number of times in a laboratory culture plate as long as cell survival conditions are met. There are many strains of HeLa cells as they continue to mutate in cell cultures, but all HeLa cells are descended from the same tumor cells removed from Henrietta Lacks. The total number of HeLa cells that have been spread in cell culture far exceeds the total number of cells that were in Henrietta Lacks body.
HeLa cells grow rapidly given the right nutrients and conditions and space. This is because HeLa cells are cancer cells which multiply and grow quickly in an uncontrolled way compared to normal cells. They can also spread and infect other cells. HeLa cells became cancerous due to infection with human papilloma virus 18. Cervical cancer is very closely associated with HPV 16 and HPV18, which can disrupt the normal activity of the cell to make cells become cancerous. However, not every woman that contracts one of these viruses will develop cervical cancer.In normal cells, cells can only divide by mitosis a certain number of times because the telomeres at the ends of the chromosomes shorten with each division. This doesn’t apply to many types of cancer cells because they produce an enzyme called telomerase, which elongates the telomeres after chromosomes are copied and allows the cells to multiply continuously.
Scientists spent more time trying to keep cells alive than performing actual research on the cells. An endless supply of HeLa cells freed up time for discovery. In 1952, the worst year of the polio epidemic, HeLa cells were used to test the vaccine that protected millions. Scientists learned to isolate one specific cell, multiply it, and start a cell line. Isolating one cell and keeping it alive is the basic technique for cloning and in-vitro fertilization. Which is used to help people have children that are unable to.
A scientist accidentally poured a chemical on a HeLa cell that spread out its tangled chromosomes. Later on, scientists used this technique to determine that humans have 46 chromosomes 23 pairs not 48, which provided the basis for making several types of genetic diagnoses. It was discovered that Lacks’s cancerous cells used the enzyme telomerase to repair their DNA allowing them and other types of cancer cells to function when normal cells would have died. Anti-cancer drugs that work against this enzyme are currently in early clinical trials.