See-Through Fish Help Cancer Research

Hugh Pickens writes "What is transparent, swims, and helps cure cancer? Caspar the friendly fish — a zebrafish bred with a see-through body to make studying disease processes easier for rapidly changing processes such as cancer, Zebrafish are genetically similar to humans in many ways and serve as good models for human biology and disease. In one experiment, researchers inserted a fluorescent melanoma tumor into the abdominal cavity of the transparent fish and by observing the fish under a microscope, they found that the cancer cells started spreading within five days and could actually see individual cells spreading. "The process by which a tumor goes from being localized to widespread and ultimately fatal is the most vexing problem that oncologists face," says Richard White, a clinical fellow in the Stem Cell Program at Children's Hospital Boston. "We don't know why cancer cells decide to move away from their primary site to other parts in the body." Researchers created the transparent fish, (photo) by mating two existing zebrafish breeds, one that lacked a reflective skin pigment and the other without black pigment. The offspring had only yellow skin pigment, essentially appearing clear."

wrong database!

[Anonymous Coward]

No, you find the gene at http://zfin.org/ [zfin.org]

here there be humor

[Dr. Eggman]

See people, we can create freakish nightmares of creation without even using genetic modification! Really, being afraid of the unnatural qualities of "Frankenfood" makes about as much sense as being afraid of "Boo-Berry" cereal.

Re:They are?

[Anonymous Coward]

Zebrafish, the nematode C. Elegans, and fruitflies have each been model organisms for years for geneticists. It's just easier to hack the underlying biology when all the scientists are focusing on the same exact species.

Not just cancer

[cvd6262]

Two great things about zebrafish:

1. You can see all sorts of diseases in them, not just cancer.

2. They're cheap. A small team at a small lab, like at a State College [brockport.edu] (see Project #4), can do good quality research with them. Even better, several small teams can be researching concurrently.

Another Transparent Creature?

[Selfunfocused]

I just read about the transparent frog [pinktentacle.com]. Did Japanese scientists do this one too? I mean, I've known they had a transparency fetish ever since I stumbled on that hentai site but this is ridiculous!

Re:They are?

[eli pabst]

Not in particular. There are a lot of conserved pathways and genes but not more than any other fish. They're nice because they're a more convenient model organism to use than mice or chimps. You can fit a lot more of them in a tank, they're relatively inexpensive, they have a short generation time, and they're more of less transparent so you can observe internal structures (particularly for developmental bio purposes) and use luminescent/colorimetric techniques with out having to do any dissections. So they do make a good model, in fact one of the genes involved in determining skin color in humans was recently identified using Zebrafish.

http://www.npr.org/templates/story/story.php?storyId=5055391 [npr.org]

Re:More to the point...

[NorbrookC]

So, clearly, cancer does not work the same way in humans and mice.

You're mistaking treatment with mechanisms. It turns out the basic mechanisms in cancer development are similar across species. The complete picture is still not known - which is why the "War on Cancer" turns out to have not produced the "cures" that were expected back in the seventies. Cancer is a generic term, covering a wide range of individual and different diseases. Understanding the biology behind it is what has been a slow, painstaking process.

A lot of cancers appear in senescence. That is, as a given organism gets older, it is more likely to develop cancer. For a human, that's in their latter 40's and 50's. For a mouse, it's around 15 months. In a population, there is going to be genetic diversity. One of the "problems" you point out, that drugs that work well with mice don't always work well with humans, can be traced to the fact that the mice used are genetically identical (they're bred that way), while humans aren't. That means that a single dosage (x amount per Kg), you will have a range of potential reactions - some people will react well, some won't at all, and some will show toxicity.

The nice thing about using fish has been pointed out. You can use a lot of them, they have a short lifespan, and you can even use a genetically diverse population. This is very useful when attempting to determine the effects of something on cancer development and incidence.