Monday, October 5, 2009

Why We Do Science, Revisited

Caption: An illustration of a telomerase molecule

Image credit: Sierra Sciences, LLC/Wikimedia

This year's Nobel Prize for Medicine has been announced. The winners are three American scientists whose research discovered telemorase, a chemical that limits how often deoxyribonucleic acid (DNA) replicate:

The recipients solved a longstanding puzzle involving the ends of chromosomes, the giant molecules of DNA that embody the genetic information. These ends, called telomeres, get shorter each time a cell divides and so serve as a kind of clock that counts off the cell’s allotted span of life.

Three Americans Share Nobel for Medicine

As this article on cell biology notes, the existence of telemorase has important implications:

A telomere is a repeating DNA sequence (TTAGGG) at the end of the body's chromosomes. The telomere can reach a length of 15,000 base pairs. Telomeres function by preventing chromosomes from losing base pair sequences at their ends. They also stop chromosomes from fusing to each other. However, each time a cell divides, some of the telomere is lost (usually 25-200 base pairs per division). When the telomere becomes too short, the chromosome reaches a "critical length" and can no longer replicate. This means that a cell becomes "old" and dies by a process called apoptosis. Telomere activity is controlled by two mechanisms: erosion and addition. Erosion, as mentioned, occurs each time a cell divides. Addition is determined by the activity of telomerase. (view animation)

Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes. Telomerase is found in fetal tissues, adult germ cells, and also tumor cells. Telomerase activity is regulated during development and has a very low, almost undetectable activity in somatic (body) cells. Because these somatic cells do not regularly use telomerase, they age. The result of aging cells is an aging body. If telomerase is activated in a cell, the cell will continue to grow and divide. This "immortal cell" theory is important in two areas of research: aging and cancer.

Facts About Telomeres And Telemorase

[italics and links from original]

A little further on in the New York Times article I quoted makes this observation:

The discoveries were made some 20 years ago in pursuit of a purely scientific problem that seemingly had no practical relevance. But telomeres have turned out to play a role in two medical areas of vast importance, those of aging and cancer, because of their role in limiting the number of times a cell can divide.

Three Americans Share Nobel for Medicine

This is yet another breakthrough that happened because someone was curious. As I've written before, this is why we do science. It's why we spend money finding out things that aren't immediately useful. Knowledge is often useful in ways those who created it can't imagine. Often, that realization only comes with time, after other discoveries are made, perhaps made by other people who are merely curious, and their implications realized.


ecrunner said...

I especially like that this finding will potentially lead to some cancer and aging treatments. It's not everyday that we find these things. I wonder what this could potentially do for different aging and brain conditions.

Cujo359 said...

It might be all of those things, but only time will tell. First, scientists have to understand the way it works, and how its workings affect the other parts of DNA molecules, and how those effects, in turn, affect our bodies. Once they know all that, they'll need a delivery mechanism.

So I think it will be a while, but it's definitely worth pursuing.