M. D. Anderson Scientist Elected to Lead Society of Toxicology
Cheryl Lyn Walker, Ph.D., an expert on genetic susceptibility to cancer and how chemical carcinogens interact with genes to launch tumors, has been elected to a leadership role in the Society of Toxicology.
Walker, a professor in the University of Texas M. D. Anderson Cancer Center Department of Carcinogenesis located at the Science Park-Research Division, won a general election of the 5,800-member society. The SOT is the world's premier scientific group for those who work to understand, prevent and better treat the harmful effects of chemical, physical or biological agents on people, other living things and on ecosystems.
She serves as vice president-elect this year, vice president in 2008, and president in 2009. "This will be an exciting time because the Society will be putting a new strategic plan in place for the coming years," Walker says.
"We want to work more extensively in global environmental health, emphasize the impact of toxicology on disease prevention, and make sure that toxicology, physiology and other related disciplines are better supported by funding from the National Institutes of Health," Walker says.
"We have the opportunity and responsibility to look beyond North America to global environmental health issues," Walker says. Arsenic and other toxins in well water worldwide and pollution in countries that formerly belonged to the Soviet Union are two examples, she noted. "For example, toxicologists and carcinogenesis experts in other countries don't always have the access to the infrastructure and resources we have here and we need to find ways to provide that access."
The SOT will work to elevate the importance of disease prevention. "Prevention is the heart of toxicology. You find out what has the potential to cause harm and make sure that people are not exposed or are protected from these agents," Walker says.
Walker studies genetic predisposition to cancer and how cancer-causing chemicals, or carcinogens, interact with genetic factors to cause cancer. Her genetic research focuses the tumor-suppressing gene Tuberous Sclerosis Complex 2 (TSC-2).
She also examines the impact of xenoestrogens - chemicals present in our environment that act like estrogens - which are taken in through environmental exposures or in food, for example the plant phytoestrogen genistein, which is present in soy. Walker studies how exposure to xenoestrogens affects the development of uterine fibroids. Fibroids occur in upwards of 50 to 75% of women and these tumors are the principal cause of hysterectomy in women of reproductive age.
Working in a rodent model, Walker has found that those with a genetic predisposition to develop fibroids and who are exposed to environmental estrogens at crucial times during development have dramatically increased risk of developing tumors later.
"This is called developmental reprogramming. When you disrupt a tissue while it's developing, you worsen the risk of disease in adulthood," Walker says. "We're finding that for this type of environmental exposure, it's all about timing, timing, timing."
Reprogramming probably is accomplished through an epigenetic mechanism, Walker says. This type of mechanism regulates genes by turning them off or on in a reversible way rather than damaging them irreversibly as would occur with a mutation.
Walker, who has been in the Department of Carcinogenesis for 15 years, won M. D. Anderson's Dallas/Fort Worth Living Legend Faculty Achievement Award in Basic Research last fall, one of the institution's five annual faculty achievement awards.