Masonic Cancer Center researchers work to identify carcinogens in the world around us—as well as ways to avoid them
When scientists talk about “environmental” causes of cancer, they don’t mean that carcinogens lurk in every tree and stream. They’re referring to anything that enters or interacts with the human body—sunshine, food, water, alcohol, radiation, cigarette smoke—and examining them for their potential to cause renegade cell growth. And as they now know, environmental factors are linked to as many as two out of every three cancers diagnosed.
DeAnn Lazovich, Ph.D., M.P.H., is one of many Masonic Cancer Center, University of Minnesota scientists investigating environmental factors with causal links to cancer. Lazovich has focused on the relationship between indoor tanning and melanoma, an often deadly form of skin cancer.
“What we discovered,” says Lazovich, “is that there is a definitive link between indoor tanning and melanoma. The more one tans, the higher the risk of getting melanoma.”
But what, if anything, can scientists do to stop people from engaging in risky behavior once a link to cancer has been identified? Like so many of her colleagues, Lazovich is every bit as interested in how to use research findings to craft public policy as she is in the research itself.
“In Minnesota, children under age 16 must have written permission from a parent, delivered in person, before they can use indoor tanning facilities,” explains Lazovich. “But we found that many parents aren’t aware of the law and that many tanning businesses don’t enforce it.”
Lazovich is now working closely with the Minnesota Cancer Alliance to pass legislation that would ban indoor tanning in Minnesota for anyone under age 18, a safety measure she believes is especially necessary because girls start indoor tanning around age 16. “We’re now seeing melanoma in people in their 20s and 30s,” says Lazovich. “It’s one of the fastest-growing preventable cancers. By hook or by crook we need to get this information out so we can stop people from exposing themselves to risk unnecessarily.”
The most infamous cause
Perhaps the best-known of all environmental causes of cancer is the cigarette, which contains numerous carcinogens and produces smoke that includes many more (see sidebar).
The news got even worse in January when the Surgeon General issued a report on the 50th anniversary of the 1964 landmark report on smoking and health. New findings have now linked smoking to such health consequences as macular degeneration, ectopic pregnancy, and rheumatoid arthritis.
Masonic Cancer Center researcher Dorothy Hatsukami, Ph.D., who holds the Forster Family Chair in Cancer Prevention, has been at the forefront of tobacco research since the 1980s, when the University became a leader in systematically examining and confirming a physical dependency on tobacco products.
Decades later, working with colleagues including Stephen Hecht, Ph.D., who holds the Wallin Chair in Cancer Prevention and Genetics, Hatsukami conducted studies proving the harms of secondhand smoke, providing support for the Minnesota Legislature’s decision in 2007 to implement a statewide smoking ban.
Today Hatsukami is concentrating on developing the scientific basis for policies that might reduce tobacco-caused death and disease, such as reducing the addictiveness and toxicity of tobacco products.
Beware charred meat
Masonic Cancer Center member Robert Turesky, Ph.D., is considered a world expert in heterocyclic amines (HCAs)—chemicals formed when meat is cooked at high temperatures.
Turesky has long been investigating how the human body transforms that class of chemicals, which are carcinogens, into DNA-damaging agents. He has fried, broiled, grilled, and charred meat to discover what temperature creates the chemicals. He has measured HCAs to determine what amount causes DNA damage. He has tested human hair follicles, where the chemicals get trapped, finding the carcinogen in the hair of meat-eaters but not in vegetarians.
“We now know the answers to a lot of the questions about exposures to HCAs,” he says, “and the short answer is, ‘Don’t eat charred meat.’ But remember, if this carcinogen is in your body, it doesn’t necessarily mean you’re going to get cancer. It just means you’ve consumed cooked meat with this carcinogen.”
A mystery, contained in wax
Turesky’s most recent discovery, published in Chemical & Engineering News and presented to the American Chemical Society, provides a way for toxicologists to go back through wax-preserved tissue samples from people diagnosed with cancer and find clues about the origin of the cancers with a suspected environmental cause, he says. More than a billion of these preserved tissue samples are thought to be in storage around the world. But scientists have been stymied because, despite years of trying, the mystery contained in those samples—preserved in a formalin solution, then embedded in a block of paraffin wax—has been tough to crack.
Turesky, who has also been studying a carcinogen called aristolochic acid that is found in certain traditional Chinese herbal medicines, used a technique called mass spectrometry to measure and identify the carcinogen linked to DNA in a fresh, frozen tissue sample. That was significant in itself. But to get a handle on how widespread the exposure to aristolochic acid is worldwide, he needed to examine older tissue samples—the ones preserved in formalin.
It’s his success in unlocking the mysteries of those samples using the same technique that has the American Chemical Society so excited.
“With this new ability to identify and measure carcinogen DNA adducts in preserved tissue samples,” says Turesky, “we can see exactly which chemicals coming from environmental exposures are doing the damage.”
To learn more or make a gift to this research, contact Cathy Spicola at 612-625-5192 or firstname.lastname@example.org.