Student/Faculty Research Team from Scottsdale Community College Publishes Paper on Cancer Research in Prominent Science Journal

~ Researchers ask: Why Don?t All Whales Have Cancer? ~

Scottsdale, AZ (September 12, 2007) ? Research conducted by Jenese Cropper and Erin Victor, students at Scottsdale Community College, and their professor, John Nagy, Ph.D., chair of the Life Sciences Department at SCC, was recently featured in the acclaimed international science journal, Nature. The article is also mirrored in the Baylor College of Medicine?s, BioEd Online, and the German science magazine Wissenschaft is also reporting on the story.  The original article was published in the journal, Integrative and Comparative Biology.

?The publication of the research project and the notoriety it received in one of the world's top journals has essentially launched the careers of these two students,? Nagy said.  ?It already played a significant role in Erin's acceptance to the naturopathic medical school, and Jenese is now thinking of becoming a research scientist. And that's just great--both students are very talented and well suited to medicine and research.?

The team?s research focused on mathematical and computer models of cancer. Worldwide, cancer kills more people than any other disease except heart disease. However, humans are not the only creatures that suffer from cancer. In fact, a stunning variety of living things are susceptible to this disease, from clams to fish to mammals.

To understand how cancer may differ in different mammals, and thereby gain insight into how the disease works in humans, the team constructed virtual tumors and ?grew? them in five different species: American pikas (a small, rabbit-like animal that lives at high elevations), woodchucks, deer, humans, beluga whales, and blue whales--the largest animal ever to exist. In total the team grew 1000 tumors in each species.

Cropper, Victor and Nagy noticed that these virtual tumors in the larger animals almost always destroyed themselves from within, whereas tumors in small animals were usually deadly. The cause has to do with tumor nutrition and evolution by natural selection.

Tumors cannot grow without blood.  To get blood, tumor cells must entice new blood vessels to grow toward them. ?That process requires a chemical symphony orchestrated by tumor cells and ?healthy? cells under the tumor?s control,? said Nagy. ?The process is not cheap; cells spend significant amounts of energy producing and releasing the required chemicals.?

In some simulations, random changes in the cells caused some cells to stop spending energy on these chemical signals and instead focused all their energy on reproduction. In essence, they became ?cheaters? that lived off of the blood supplied by other cancer cells. Because these cheaters reproduced faster than their competitors, they soon became the most abundant cell type in the tumor. But, because they were incapable of generating new blood vessels, eventually the entire tumor starved to death.

In the simulations, such ?tumors on tumors? tended to develop much more often in large organisms, especially whales, than small ones. As a result, tumors rarely killed the whales but almost always killed the smallest mammals, pika and woodchuck.  A deadly tumor in a woodchuck is about the size of a quail egg or large grape. A deadly tumor in a blue whale is as big as 2000 quail eggs (about 32 inches in diameter). So, it takes much longer for a tumor to reach lethal size in a whale than it does in a woodchuck. But, that allows more time for ?cheaters? to evolve in whales, which accounts for why tumors were less deadly in these creatures.

This observation may explain a paradox, called Peto?s paradox, that has perplexed cancer biologists for over 30 years. Superficially, one expects large creatures to suffer more cancer than small ones because large animals have many more cells and tend to live longer. Yet it appears that mice, humans and whales are essentially equally susceptible to cancer, or at least no relation between cancer rates and body size has been seen. If this self-defeating cancer idea is correct, then large animals actually do suffer more cancer, but in them it rarely represents a health risk.

?Although the research focuses on general cancer biology?that is, it was not intended to generate any immediate clinical application--the concept of a self-defeating tumor may be clinically relevant,? said Nagy.  ?If we can find a way to induce these ?cheater? cells in existing tumors, we may be able to force tumors to destroy themselves from the inside.?

John Nagy, Ph.D. is the Chair of the Department of Life Sciences at SCC.  His bio can be found here: http://www3.sc.maricopa.edu/nagy/

Jenese Cropper is a graduate student working towards a degree in Pharmacy with a deep love of Biology. She obtained a bachelor?s degree in History and TESL (Teaching English as a Second Language) from Brigham Young University. She has taught school in Southern California and Las Vegas, Nevada, and is currently working as the ESL Coordinator for Academy of Arizona.  She is thinking about switching from Pharmacy to Biology and pursuing a PhD to teach.

Erin Victor worked with Dr. Nagy and fellow students on a research project involving cancer in vertebrates. It was an incredible and very rewarding learning experience for her.  She met Dr. Nagy while she was taking prerequisites at Scottsdale Community College for admission to Southwest College of Naturopathic Medicine where she is currently a first year student in their four year doctorate program. She received her undergraduate degree in Public Relations and Spanish from Northern Arizona University in 2003.

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About Scottsdale Community College
Scottsdale Community College offers over 1,500 academic and non-credit classes each semester. Located on the Salt River Pima-Maricopa Indian Community, the campus is known for its serene atmosphere and beautiful plant and wildlife. With nearly 12,000 students, Scottsdale Community College is proud to offer high-quality, affordable programs in small class settings. From Motion Picture/Television Production and Culinary Arts to Nursing and American Indian Studies, students have a wide variety of programs from which to earn credits for university transfer, launch their careers, train for new ones, or pursue a special interest. The SCC Business Institute offers customized programs to meet the needs of local business. Scottsdale Community College is one of the ten Maricopa Community Colleges.

To learn about the many academic programs at Scottsdale Community College, call us at (480) 423-6000 or visit our website at www.scottsdalecc.edu.

Media contact:
Denise Kronsteiner
(480) 423-6567
denise.kronsteiner@sccmail.maricopa.edu

Life Sciences Department contact:

Dr. John Nagy

(480) 423-6121

john.nagy@sccmail.maricopa.edu

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