Comment The staright skinny on telomeres (Score 1) 518
Telomeres are DNA repeats at the end of our chromosomes. All creatures seem to have them. Their function seems to be to control how often a cell can replicate.
When chromosomes replicate, the DNA strands split down the middle and an enzyme reads the DNA and produces a copy very similar to how a tape recorder plays an audio tape. The problem with this replicating enzyme is that it needs to hold onto something as it starts reading. This little bit of DNA it holds onto is not copied. This results in a loss of about 6 DNA base pairs per copy (ie. per cell relpication) of the telomere in humans. After a certain number of replications, the telomere is used up and the 6 base pair loss starts eating into important genetic material. Eventually the cell stops replicating and becomes 'senescent'.
Telomerase is an enzyme who can replace these lost base pairs after replication. In humans it is found mainly in germ line cells (sperm and egg cells), bone marrow (makes red blood cells), and - drum roll - cancer cells. This seems to explain why cancer cells are immortal and our normal cells are not.
Two exciting ideas (among many) have emerged from telomere research. The first is that if an 'anti' telomerase can be found, it will be a cure for many, many kinds of cancer. The second is that if we can introduce telomerase into our normal cells, we will live much, much longer.
The company doing the most research into this is a quiet, odd firm started by an American tycoon called Geron Corporation. You can surf them at http://www.geron.com. Geron recently revealed that introducing telomerase into normal humans cells seems to make them immortal.
Exciting stuff.
When chromosomes replicate, the DNA strands split down the middle and an enzyme reads the DNA and produces a copy very similar to how a tape recorder plays an audio tape. The problem with this replicating enzyme is that it needs to hold onto something as it starts reading. This little bit of DNA it holds onto is not copied. This results in a loss of about 6 DNA base pairs per copy (ie. per cell relpication) of the telomere in humans. After a certain number of replications, the telomere is used up and the 6 base pair loss starts eating into important genetic material. Eventually the cell stops replicating and becomes 'senescent'.
Telomerase is an enzyme who can replace these lost base pairs after replication. In humans it is found mainly in germ line cells (sperm and egg cells), bone marrow (makes red blood cells), and - drum roll - cancer cells. This seems to explain why cancer cells are immortal and our normal cells are not.
Two exciting ideas (among many) have emerged from telomere research. The first is that if an 'anti' telomerase can be found, it will be a cure for many, many kinds of cancer. The second is that if we can introduce telomerase into our normal cells, we will live much, much longer.
The company doing the most research into this is a quiet, odd firm started by an American tycoon called Geron Corporation. You can surf them at http://www.geron.com. Geron recently revealed that introducing telomerase into normal humans cells seems to make them immortal.
Exciting stuff.
