The Real Fountain of Youth

Dateline: 01/22/98

Wow, first cloning and now immortality? Okay, we're jumping the gun a bit. But seriously, scientists announced that they have succeeded in producing cells that divide many times over their normal limit. In normal cells, division takes place a certain number of times and then the cell stops dividing. Likewise, cells in vitro usually divide about 50 times or so before they cease dividing. Scientists succeeded in producing cells that divided over 90 times with no signs of slowing down! But how?

In the nucleus of a cell, each chromosome contains the genetic information, aka DNA, for the individual. When cells divide, DNA is replicated. On the end of chromosomes is a protective "cap" of sorts, called a telomere. As cells divide, the telomere becomes shorter and shorter until the cell ages and stops dividing. Scientists have known that telomere shortening is associated with the aging process, but it wasn't known whether shortening is an exact cause or a byproduct of aging.

Last week, scientists at Geron Corporation and the University of Texas Southwestern Medical Center added an enzyme called telomerase to the cell's chromosomes. Telomerase caused the telomeres to grow longer, thus circumventing the normal shortening process. From this experiment, scientists were able to conclude that telomeres do act as a biological clock in the aging process.

This could have interesting implications. Theoretically, scientists would be able to treat a variety of genetic defects and/or diseases by removing a group of cells from a person, rejuvenating them, and returning them.

There are several unanswered questions. Because cancerous cells have telomeres that do not shorten, there is some debate whether or not the natural shortening of telomeres is an evolutionary adaptation to ward off cancer. By circumventing this natural process, we may in fact be destroying a natural defense mechanism of the body. As additional experiments and investigations are performed, we will be better able to see if this process is indeed an "immortality" breakthrough.

What do you think? Will we achieve cell immortality? What are the implications for future generations? Stop by the Biology Forum and join the discussion. Let your voice be heard! 'Til next time...

For additional information see:

• Scientists Extend The Life Span Of Human Cells
  Report about telomeres and aging from Science Daily.