|Fall 2009-Scientist Profile|
Tim Nagy, Ph.D., fights cancer wearing two uniforms. The first is his lab coat, which he wears as a UAB Comprehensive Cancer Center scientist and vice chair for research in the UAB Department of Nutrition Sciences. The second uniform involves a helmet.
That’s because Dr. Nagy races sports cars—often to raise money for the Cancer Center. “I was one of three driving for the Cancer Center in an eight-hour endurance race at Road Atlanta in December,” he says. “We raised money for every lap we completed, which added up to a couple thousand dollars. Our next race is at Barber Motorsports in Birmingham, and I’ve got a Cancer Center logo on my front windshield. So hopefully we can raise more money.”
The Hormone Link
“Many people thought an increase in food consumption confers this risk,” Dr. Nagy says. “That’s certainly possible, but our research so far suggests that elevated risk is actually caused by addition of body fat. Scientists no longer think of body fat as tissue that just holds excess calories, holding energy in reserve. In fact, extra body fat is an endocrine tissue that produces hormones. As you increase the amount of fat, certain hormones are produced in excess, and other hormones are produced less. We think that many of these hormones may play a role in the discrepancy in mortality rates.”
One of those hormones, leptin, is produced in very high amounts in obese individuals, and it fosters cancer cell growth by allowing blood vessels to grow and feed tumors, Dr. Nagy explains. Another hormone, adiponectin, decreases as obesity increases—and the lack of it may also encourage cancer. Unlike leptin, adiponectin can inhibit cell growth by limiting the expansion of blood vessels. In other words, Dr. Nagy says, obesity may provide tumors with an environment where they can grow and flourish, while leanness starves them.
The Science of Obesity
In the study of women who were mildly overweight and then reduced their weight to normal levels, Dr. Nagy and his team found that “in the overweight state, cancer cells tend to grow better. The cell cycle and cell division tends to go more quickly, and there’s less cell death in the overweight state compared to the normal weight state of the same woman. In the normal weight state you see more apoptosis, or cell death, which means there’s better control of the cell cycle and cellular regulation.”
A new project will study obesity’s relationship to metastatic disease, Dr. Nagy adds. “This is a really important area because people mostly die from metastatic disease rather than initial tumors.”
The studies could benefit patients in multiple ways, adds Dr. Nagy. “Understanding the hormones and other physiological factors involved in the weight-gain, weight-loss loop might help us devise methods to change them. If we know a certain hormone is involved, drugs might be developed to limit production of that hormone.”
“Then I wanted to do a little more, so I participated in time trials,” he says. “That was a lot of fun and paved the way for my entry into racing. I participate in club racing at places like Barber Motorsports or at Road Atlanta.”
Dr. Nagy does all of the maintenance and repair work on his Porsche himself. “I thought that if I could do science, then I could probably work on a car,” he says. “I put in new engines, rebuild engines, repair transmissions—everything. Now, my family lovingly refers to my garage as ‘man haven.’”