Friday, October 11, 2013

Naked Mole Rats: The Cure For Cancer?

          Genetically modifying animals has come a long way, from selectively breeding dogs to our heart's desire to adding green fluorescent protein (GFP) genes into zebrafish embryos to produce fish that glow green while swimming around. Advances in genetic modification have been astounding and the transition into labs has given us more control over how certain genes are expressed and where they are located in the genome. Ever since Watson and Crick (and let us not forget Rosalind Franklin) discovered the structure of DNA in 1953, the field of genetics has been growing in science. The breakthrough of completing the human genome project in 2003 was yet another great step in the development of genetics. Such advances in this field have led to the development of biotechnology, or the use of organisms and living systems to make beneficial products or to further our understanding of the life.
          Science has given us the chance to manipulate life for either the better, or for the worse. Manipulation of genes has gone so far as genetically modifying goats to produce human lysozyme in their milk for the treatment of intestinal problems (both human and goat) by introducing the human lysozyme gene into goat embryos. Work with cloning, while not yet perfected, has made major discoveries in the process of how to clone our favorite family companions. Adding specific genes to zebrafish results in fish that glow red, green, yellow, blue, or even purple under certain light (which I have to say is quite fascinating to see). However, companies also produce mice that have all sorts of diseases from Alzheimer's disease, NSE-p25 mice, to mice that just drop dead from heart failure, 11BHSD2 mice, for research labs. The question then becomes, are these manipulations morally acceptable? Everyone has their own opinion but as Emily Anthes, author of Frankenstein's Cat: Cuddling Up to Biotech's Brave New Beasts, puts it, "studying these creatures yields valuable insight into human disease" (Anthes p.8-9) and these studies could even provide insight into how to help these animals fight disease. As for the glowing fish, GloFish, I have to agree with Anthes in that as long as the new genes are not causing any harm to these animals, then there is no cause for concern. In fact, there is less harm caused by many of these genetic laboratory changes than the harm caused by the selective breeding of dogs. Years of inbreeding and selecting for certain traits have resulted in dogs like the English bulldog that suffers from sleep apnea because its snout is so short. Its breathing difficulties result in "trouble regulating [its] own body temperature" (Anthes p. 29) and even heart or respiratory failure.
          Ultimately, manipulation of genes certainly has both positives and negatives, but we cannot forget the benefits. Recent studies have observed naked mole rats and their curious resistance to cancer. Vera Gorbunova and Andrei Seluanov of the University of Rochester have discovered that naked mole rats from East Africa have the strange ability to fight off cancer when injected with viruses that normally trigger cancer in mouse cells. What causes this protection? A chain-shaped molecule by the name of hyaluronan that prevents cancer cells from multiplying out of control. Naked mole rat cells actually grow at a third the density that mouse cells do because of this hyaluronan molecule. Hyaluronan, also found in the stretchy gel that holds human cells together, actually sends signals into cells through the CD44 receptor that instructs cells to change their direction of growth, or even to start multiplying. These naked mole rats have high levels of this molecule, but it is five times as long! Experiments in which enzymes destroyed this hyaluronan or experiments that shut down the hyaluronan  producing gene resulted in cells that multiplied drastically. Such results show that this molecule helps the naked mole rats fight cancer, but they did not evolve in this way to fight cancer originally. Naked mole rats need to wiggle through underground tunnels, and stretchy skin, as a result of the long hyaluronan, helps them do just that. This necessary adaptation also fortunately prevented these mammals from developing cancer.
          Looking into the future, these findings can have major implications on a cure for cancer. Further research must be done to see if this has the potential to be a cure, but it will not be the only cure if so. Research must first be done on animals that do not have this long of hyaluronan, such as mice. Mice, as mentioned earlier, have been bred for all kinds of diseases, but this time they will be used to see if this long form of hyaluronan will prevent the growth of tumors. Using these mice to observe the effects of long hyaluronan is a way to genetically engineer so that we can better understand. Looking at the effects on an organism that normally does not have this gene can help us determine how it would affect a human.
          Anthes argues that using an animal to test the effects of genes is morally acceptable if some benefit can come from it. Doing this research can improve both the lives of humans and even mice by reducing the risk of cancer. This research is certainly justified and may potentially result in a new way to treat
in the field of medicine.

Sources:

Anthes, Emily. Frankenstein's Cat: Cuddling Up to Biotech's Brave New Beasts. , 2013. Print.

Zimmer, Carl. "A Homely Rodent May Hold Cancer-Fighting Clues". New York Times. June 19, 2013.
<http://www.nytimes.com/2013/06/19/science/a-homely-rodent-may-hold-cancer-fighting-clues.html>

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