Nobel Price Winners Isolate Protein Behind Immortality
This year’s Nobel Prize in medicine went to a trio of scientists who discovered the enzyme telomerase, which allows cells to divide without any limits, making them effectively immortal.
It may be nature’s greatest double-edged sword. Coax cells into producing telomerase, and they will survive indefinitely, but they will also become cancerous.
To safeguard against cancer, adult cells keep track of how many times that they have multiplied, and once they have reached a pre-set limit — often around 80 divisions — they die. Telomerase interferes with this record keeping.
If you can find a drug or gene therapy that interferes with telomerase, it could fight the unchecked growth of cancer cells, said Mark Muller, a cancer researcher who studies telomeres at the University of Central Florida.
“Ninety percent of all cancer cells are telomerase rich,” Muller said.
Several companies, including Geron, have started testing drugs that gum up the telomerase enzyme, so that it can’t extend the lives of cancer cells.
Telomerase lengthens telomeres, repetitive DNA sequences that sit at the ends of chromosomes. Each segment of a telomere is like a ticket that gives it permission to divide. When cells run out of those credits, they cease dividing.
Geron is developing a modified DNA molecule that gets stuck inside of telomerase, so that it can’t build up the ends of telomeres in cancer cells. The company is also working with a vaccine that trains cancer patients’ immune systems to attack cells that produce telomerase. In adults, almost all of the cells that produce telomerase are cancerous. Those cancer treatments took shape almost 20 years after academics made a breakthrough discovery.
In the early 1980’s Elizabeth Blackburn, Carol Greider and Jack Szostak identified telomerase and learned how it works. Some scientists speculated people could live longer by using the enzyme to buy extra time for their aging cells, but that idea remains risky and unproven.
“By itself, lengthening telomeres would probably just increase the rate of tumor formation,” said Chris Patil, a researcher at the Buck Institute for Age Research in Novato, California. Experiments with mice have shown that lengthening telomeres extends lifespan, but only if you introduce multiple other mutations to block cancer.”
Considering the risks of telomere-extension therapy, he thinks that scientists have bigger fish to fry.
“In the absence of a comprehensive understanding, it’s very dangerous,” Muller said. “We have to figure out how to do maintenance on our telomeres.”
Muller thinks humans could live for 90 to 210 years once scientists know more about the molecular basis of aging.
“If we could figure out how to do maintenance, we could extend our lives,” he said. “But it has to be done very carefully, and we’d have to have a comprehensive understanding of the mechanism.”
(from Wired Science, wired.com)
Two more ways to achieve immortality1. The human cells die because they get exposed when the liquid surrounding them damages. The scientist came with an idea, that by keeping undamaged the liquid coating the cells (therefor forever protected), they are able to achieve cellular immortality.
2. HeLa, the first immortal human cells and a tale of immorality.
When we work with cell lines in the lab, we often work with HeLa cells. They can live in a vial of nutrients, and from a small sample you can grow a large quantity to use in cancer research, in vitro fertilisation research, stem cell research, virus research, pretty much any kind of human biology research actually. They’re a biologist’s wet dream.
Usually, when one take some cells out of a person they die pretty soon after. Henrietta Lacks has been dead for over 60 years but those cancer cells are still going strong. Which is pretty amazing! They are also very weird looking. HeLa DNA has been extremely mutated, instead of 46 chromosomes it has 82. That strange DNA makes it do some pretty amazing things: It replicates abnormally fast, even for cancer cells, and it has an active copy of telomerase which means it can replicate indefinitely. Most other cells age as they divide until they reach the Hayflick Limit, then they don’t divide no more. Not HeLa.
HeLa cells revolutionised our understanding of human biology, but the family of Henrietta have yet to see a cent of it. In fact, those cells were taken from her without her knowledge.
Passage from the book “The Immortal Life of Henrietta Lacks":
"Her name was Henrietta Lacks, but scientists know her as HeLa. She was a poor Southern tobacco farmer who worked the same land as her slave ancestors, yet her cells—taken without her knowledge—became one of the most important tools in medicine. The first “immortal” human cells grown in culture, they are still alive today, though she has been dead for more than sixty years. If you could pile all HeLa cells ever grown onto a scale, they’d weigh more than 50 million metric tons—as much as a hundred Empire State Buildings. HeLa cells were vital for developing the polio vaccine; uncovered secrets of cancer, viruses, and the atom bomb’s effects; helped lead to important advances like in vitro fertilization, cloning, and gene mapping; and have been bought and sold by the billions. Yet Henrietta Lacks remains virtually unknown, buried in an unmarked grave."
The Terran human race is almost for sure the youngest specie in the Universe: only few hundreds of thousands of years old. If we discovered immortality, can we even imagine what "science" or "medicine" means for a billion years old specie?
