November 3, 2015 | by City of Hope
Two leading City of Hope researchers have received a National Institutes of Health grant to investigate a long-held view that environmental factors could incite the development of breast cancer. An intriguing twist of their research, however, is that when a woman is in menopausal transition, it may increase the probability of developing the disease due to environmental pollutants.
“We believe that during this time, when natural hormone levels are declining, environmental endocrine-disrupting chemicals promote hormone-responsive breast cancers,” said Shiuan Chen, Ph.D., professor and chair of the Department of Cancer Biology. Chen and Susan L. Neuhausen, Ph.D., The Morris & Horowitz Families Professor in Cancer Etiology & Outcomes Research, are co-principal investigators on the study.
The five-year, $4.8 million grant will examine the possible role of environmental exposure in the development of breast cancer during this time of menopausal transition in women.
Chen and Neuhausen’s study is based on an increasing body of evidence supporting the link between environmental factors and breast cancer. That evidence suggests there may be specific windows of susceptibility when a woman’s body is more vulnerable to carcinogenic changes in breast tissue. Breast cancer statistics suggest that one such time of vulnerability could be the menopausal transition, when menstrual periods become less regular and eventually cease.
The City of Hope research team will assess the impact that a class of persistent organic pollutants has on aromatase, estrogen and progesterone receptors in women going through menopause. The goal is to determine if two types of compounds — bis-phenol A and polybrominated diphenyl ethers — promote breast cancer during menopause. To accomplish this, Chen and Neuhausen will evaluate these processes through in vitro cell line experiments, in vivo mouse models, and observational studies of effects in women in the menopausal transition.
The team will analyze blood samples from women who participated in the California Teachers Study, a cohort of educators followed since 1995 that allows researchers to investigate environmental, genetic and other factors that may cause cancer.
In addition to evaluating blood samples and publishing outcomes, the City of Hope project includes developing resources for educating and engaging the community about environmental exposures and breast cancer risk.
Other City of Hope investigators participating in the project include: Leslie Bernstein, Ph.D., R.N., Kimlin Tam Ashing, Ph.D., Noriko Kanaya, Ph.D., Yuan Chun Ding, Ph.D., M.S., Xiwei Wu, M.D., Ph.D., Sierra M. Li, Ph.D., and Tim Synold, Pharm.D. Additional key researchers are Peggy Reynolds, Ph.D., and David Nelson, M.D., M.P.H., of the Cancer Prevention Institute of California and Michele Rakoff, a patient and research advocate.
The grant is funded through the Breast Cancer and the Environment Research Program (BCERP), which is a joint effort co-funded by the National Institute of Environmental Health Sciences and the National Cancer Institute. The goal of BCERP is to support transdisciplinary research to enhance knowledge of environmental and genetic factors underlying breast cancer risk.
City of Hope was among six U.S. institutions to receive a BCERP grant, which funds studies on women’s health issues. The title of Chen and Neuhausen’s project is, “Menopausal Transition – A Window of Susceptibility for the Promotion of Breast Cancer by Environmental Exposures.”
Find out more about City of Hope's breast cancer research.
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