Do Any Cells Live Forever?
Some cells appear to be able to live forever in a lab. However the Hayflick limit sets a cap on the number of times a cell can divide. Even cells that can divide forever (cells that negate the Hayflick limit due to mutation, like cancer cells), can die from means other than biological aging. So there is no truly immortal cell.
Below we look at cancer cells and other [almost] “immortal” cells to understand how some cells negate the Hayflick limit.
How Do Immortal Cells Work?
A small part of each cell, the telomere at the end of each chromosome, is worn away every time a normal cell divides. In immortal cells like cancer cells, telomerase can be activated so that these cells maintain their telomere’s length and do not wear out. These cancer cells are said not to have a Hayflick limit, a limit to the number of times a cell can divide.
Perhaps the most well-known of these apparently immortal cells are the cancer cells that killed a woman named Henrietta Lack in the 1950s. Her cells, known as HeLa cells, have been able to keep dividing as long as they have nutrients. The cells were taken without permission and have enriched companies that grew and marketed them for decades, while her descendants live in poverty, which gives rise to many complex ethical questions.The immortal cells of Henrietta Lacks – Robin Bulleri.
FACT: Some cells appear to live forever. The telomerase in cancer cells, which limits other cell’s lives, can be turned on indefinitely so that cells do not die. They appear exempt from the Hayflick limit, which limits cells to between 40-60 divisions.
What are the Different Theories of Cell Division?
People used to think that all calls could be kept alive indefinitely in a culture. Alexis Carrel, who won a Nobel Prize in 1912 for vascular suturing, was probably the best-known proponent of this theory.
Dr. Leonard Hayflick began conducting experiments on cell mitosis (a process used by cells to divide and duplicate themselves) in 1965. He found that cells have a finite number of times that they can divide before they die. The usual number of times a non-cancer cell can divide seems to be between 40 and 60 times. The number of times that any cell can divide is limited in both fetal and adult cells.
The following YouTube video helps explain the Hayflick limit.Hayflick limit-YouTube.
What Influences the Hayflick limit?
There is considerable controversy about factors that may or may not prolong the ability of cells to survive. There are a great many likely culprits for cell aging. For a list see: It is possible that lifestyle or dietary modifications can influence the rate at which cells divide. Even given the Hayflick limit, we have many questions left to explore.Biological Immortality The Hydra. The immortal Hydra! An example of a biologically immortal cell-based life-form.