Spokesman Review (Spokane, Wash.)  [Printer-friendly version]
September 15, 2006

WASHINGTON STATE UNIVERSITY FINDS TOXIN, CANCER LINK

Study finds link during pregnancy

[Rachel's introduction: Pregnant rats were exposed to high levels of
a fungicide commonly used in vineyards. In male offspring and three
subsequent male generations of the rats, 85 percent of the animals
developed cancer, prostate disease, kidney disease, premature aging
or other problems.]

By Shawn Vestal

New research by Washington State University scientists suggests that a
single exposure to environmental toxins during pregnancy can cause
cancer, kidney disease and other illnesses for future generations.

The research, led by WSU professor Michael Skinner, suggests that
environmental pollution could permanently reprogram genetic traits in
a family line, creating a legacy of sickness. It follows previous
studies in Skinner's lab that showed similar long-term effects from
toxins on the reproductive systems of successive generations.

"It's a new way to think about disease," Skinner said in a WSU news
release. "If this pans out, it gives us a host of new diagnostic and
therapeutic tools."

It also provides possible explanations for increases in some diseases,
as well as spikes in illness that are tied to a geographical region.
And it highlights the potential long-term dangers from environmental
pollution, said Skinner, the director of WSU's Center for Reproductive
Biology.

In the research, pregnant rats were exposed to high levels of a
fungicide commonly used in vineyards. In male offspring and three
subsequent male generations of the rats, 85 percent of the animals
developed cancer, prostate disease, kidney disease, premature aging or
other problems. Most of the rats developed more than one illness.

The research was published in two papers Thursday in the journal
Endocrinology.

Skinner's lab has been working on the question of "epigenetic
inheritance" for years, and published research last year that showed
toxic exposure during embryonic development could hurt fertility over
several generations. Epigenetic inheritance involves chemical
modifications in the operation of genes from parent to offspring -
changes in which the DNA itself isn't modified, but the way the genes
"turn off" and "turn on" is affected, WSU said.

The new research suggests an environmental toxin can permanently
reprogram an inheritable trait.

Skinner and a team of WSU researchers exposed pregnant rats to the
fungicide vinclozolin during a period when the sex of the rats'
offspring was being determined. It's a state of development when
embryos are susceptible to genetic reprogramming, WSU said in its news
release.

The rats were exposed to higher levels of the toxin than are normally
present in the environment, and more research is needed to see if
lower levels show the same effects.

Pregnant rats exposed to the toxin produced male offspring with low
sperm counts and high rates of disease. When those rats mated with
females that weren't exposed to the fungicide, their male offspring
had the same problems -- a situation that persisted through four
generations.

"A human analogy would be if your grandmother was exposed to an
environmental toxicant during mid-gestation, you may develop a disease
state even though you never had direct exposure, and you may pass it
on to your great-grandchildren," Skinner said.

Skinner said the findings might be applicable to the study of breast
cancer and prostate disease, which are increasing faster than would be
expected from genetic changes alone.