Expert: Dana Krempels, Ph.D. - 10/10/2008

Question
I remember reading several years ago about a research being done on cell life and regeneration.  I believe it went something along the lines that every cell has something that can conceptually be thought of as a tail of segments.  The number of segments represents the number of times the cell can regenerate.  The article alluded to the fact that if they could increase the length of this 'tail' then theoretically people's cells could regenerate for ever and people could possibly live forever.  Do you think there is any truth in this, or possibility of this happening in the future?  Thanks, Trenton

Answer
Dear Trenton,

What the article was probably referring to was the telomeres:  the "caps" on either end of the chromosomes in a eukaryotic cell.  You can find a version of the hypothesis in the article you read here:

http://www.viewzone.com/aging.html

Every time a cell divides, it has to duplicate its chromosomes (in a human cell, that's 46 chromosomes) so that each new daughter cell will have the same number (and hence, complete genetic information) of the original parent cell.

Unfortunately, because of the way the telomeres are arranged, a special enzyme known as telomerase is necessary to duplicate them without losing bits of telomere with every cell division.  And even with telomerase, the telomeres still tend to become shorter with every cell division.

Some researchers have been trying to establish a link between the shortening of the telomeres and aging, but this link is neither universally accepted nor well understood. There are many different aspects to the aging process, and telomere shortening may be only one small piece of the puzzle.

There is certainly truth in this hypothesis.  But I am not convinced that merely by preventing telomere shortening that we could be immortal.

Hope that helps!

Dana