Pollution may cause prostate cancers to become more aggressive
Environmental pollutants may cause slow-growing prostate cancers to become more aggressive, according to preliminary research carried out at the Medical College of Wisconsin.
If a slow-growing cancer becomes more aggressive, they may attack surrounding tissue, and spread more rapidly through the body. The research suggests that dormant cells may become aggressive if the patient is exposed to pollutants such as heavy metals, cigarette smoke, pesticides, or car and truck emissions.
Doctors have long known that some prostate cancers grow very slowly and do not invade surrounding tissue, while other men’s prostate cancers spread quickly and can lead to death. They didn’t – and still don’t – know why. This research may yield a clue.
“When most people think of environmental agents, they think of how these agents can cause cancer,” Dr. Andre Balla, associate professor of pathology said. “We are proposing that they also act on already established cancers.”
Dr Balla worked with Dr Paul Lindholm assistant professor of pathology, in order to test the theory that environmental factors might play a role.
Dr Lindholm first had find out what made aggressive prostate cancer cells different from dormant cells. During the 1950s, investigators at other centres were able to grow prostate cancer cells in tissue cultures.
Medical College researchers have isolated and identified ten genes that are turned on only in aggressive variants of those cells. Their findings about these aggressive-associated genes and their behaviour were presented at the American Association for Research meeting in Philadelphia on April 11, 1999.
Step two in their research is to find out if pollutants in the environment can turn non-aggressive prostate cancer cells into killer cells. They also want to find markers that indicate aggressive cancer behaviour, and identify the target molecules in cancer cells to aid in finding a cure.
The researchers are subjecting non-aggressive cancer cells in the lab to environmental pollutants including certain insecticides, cadmium (a heavy metal present in batteries, cigarettes, contaminated water and food) and cigarette smoke tar.
“Now we are finding out if some of those ten genes are activated by these environmental pollutants in less aggressive cells also,” Dr. Balla said. “We don’t know yet what these pollutants would do in experimental animals or in men with prostate cancer; what happens in tissue cultures may not happen in patients, but this is a very good start.”