Chronic low-level exposure to a compound found in a variety of plastic household items could pose a threat to women who overproduce a protein linked with breast cancer, say researchers at University of Alabama at Birmingham.
Coral Lamartiniere, Ph.D., professor in the Department of Pharmacology and Toxicology and senior scientist in the UAB Comprehensive Cancer Center, and postdoctoral fellow Sarah Jenkins, Ph.D., assessed the effect of chronic, oral exposure to the compound bisphenol A (BPA) in mice genetically modified to overproduce the protein HER2/erbB2, present in about 15-30 percent of women with breast cancer. The results were published online Oct. 12, 2011, by the journal Environmental Health Perspectives.
"We found the lower doses of BPA to be capable of activating several growth-factor-receptor pathways that previously have been implicated in cancer. This was not observed with the higher BPA doses," Jenkins says. "This is counterintuitive since BPA in low levels was presumed to be safe."
BPA is an industrial compound primarily used to manufacture polycarbonate plastic and epoxy resins and it is commonly found in household items including kitchen utensils, food storage containers, travel mugs and metal can linings. Animal studies have linked BPA to a variety of health problems such as infertility, prostate cancer and breast cancer, but not without disagreement as to how and whether such findings can be extrapolated to humans.
Most BPA research has been centered on early-life exposure in animals, linking low doses of BPA administered early in life — prenatal, pre-pubertal or a combination of the two — to an increased risk of mammary cancer later in life.
"Although this study did not study breast cancer in humans, the results suggest that chronic low-level BPA exposure could pose a particular threat to women with breast cancer who overproduce this protein," Jenkins says.
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