Estrogenic Compound in Plastic Linked to Prostate Cancer

Gail Prins, Ph.D.
University of Illinois at Chicago
R21ES12281

Bisphenol A, a common chemical found in many types of plastic, permanently alters genes and leads to prostate cancer according to a new study published in the June 1 edition of Cancer Research. These results represent the first evidence that early exposure to low doses of environmental estrogens during prostate development in the male fetus may result in prostate cancer later in life.

A research team led by Gail Prins, a grantee of NIEHS, exposed pregnant female rats to low doses of either estradiol or bisphenol A during the development period corresponding to the second and third trimesters of human pregnancy. They found that this early exposure predisposed the male offspring to precancerous lesions of the prostate gland later in life.

The researchers determined that the early estrogenic exposures had their effects through a process known as epigenetic reprogramming. Epigenetics is the study of heritable changes in gene function that occur without a change or mutation in DNA sequence. They found that methylation of the gene coding for the enzyme phosphodiesterase 4 permanently altered its expression in prostate tissue. Normally, this gene is expressed at very low levels in adult mammals, but after early exposure to the estrogenic compounds, the animals continued to have high levels of expression of the gene in their prostate glands throughout their lives. In additional studies using cell cultures, high levels of gene expression were also found in prostate cancer cell lines.

The authors point out that application of these findings to human prostate cancer requires additional studies. However, since the methylation of the gene can be found before any disease has occurred, it may be useful as an early biomarker and provide a means for the early identification of men at risk for prostate cancer.

Citation: Ho SM, Tang WY, Belmonte de Frausto J, Prins GS. Developmental exposure to estradiol and bisphenol A increases susceptibility to prostate carcinogenesis and epigenetically regulates phosphodiesterase type 4 variant 4. Cancer Res. 2006 Jun 1;66(11):5624-32.