Product Reviews from a Scientific Perspective

Friday, January 28, 2011

Exploding Chromosomes and Cancer

A recent New York Times article reports that some researchers find that many cancers begin from a chromosome that "explodes."
New rapid methods of decoding DNA have brought to light a catastrophe that can strike human cells: a whole chromosome may suddenly shatter into pieces.
If the cell survives this disaster, something worse may ensue: the cell becomes cancerous.
Apparently "Dr. Campbell’s group reports that about 2 percent to 3 percent of all cancers, and 25 percent of bone cancers, originate in this kind of chromosome-shattering crisis," writes author Nicholas Wade.

Cancers, despite their superficial diversity (for example, lung cancer, brain cancer, stomach cancer, etc etc.) and their seemingly wide causes (environmental chemical pollutants, UV radiation from the sun, smoking, HIV), are fundamentally they same. They all involve cells that, instead of multiplying in a regular, orderly fashion, just can't stop multiplying. As one doctor once said to me, "it's like it turns into The Hulk."

Within every human cell is the ability to divide, and multiply. From one cell you get two. A somewhat complicated
mechanism keeps your cells dividing either too much or too little. This mechanism depends on a certain part of your cells' DNA, which of course is bunched up into bundles called chromosomes. 

When something screws around with the part of your DNA that schedules your cells' multiplying, they can start to multiply too much. And when they start to multiply too much, you get a tumor - a cluster of cells that just can't stop. 

Your body depends on a balance of different cells, and each of your organs depends on each type of cell working in good balance, in good harmony, with the other types of cells. So when you have a whole bunch of cells that just won't stop growing, that's bad news for your body. 

The exploding chromosome is interesting, because when it explodes, it might be pieced back together. Your body's cells are actually capable of repairing its own DNA, like a newspaper editor looks over an article for mistakes. But it's not perfect. Sometimes the mistakes it allows to go through, or worse, creates a mistake of its own. As Wade explains,
...the chromosome must have shattered into pieces in a single event; the cell then knitted them together as best it could, but in the wrong order.
Usually a cell that suffers this much damage will destroy itself, either immediately or after it has tried unsuccessfully to repair its chromosomes. But in certain cases, the self-destruct mechanism evidently fails, leaving a cell like Frankenstein’s monster, with badly patched-up chromosomes but a survival advantage that leads to unrestrained growth.
The implications for treating cancer are not obvious, but it can encourage treatment that doesn't involve chemotherapy, which is essentially bombarding tumors with radiation. Radiation, of course, is another source of destruction to DNA that could result in more cancerous cells.

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