( d packaging dental sealants and polyca...)Compounds in plastic packaging act as environmental estrogens altering breast genes

"In exposing prepubescent female rats to BPA and BBP, our aim was to determine what effects, if any, each compound had on mammary gene expression during at different ages," said Moral.

"Our results showed that exposure to BPA changes the gene expression profile of mammary tissues as a function of age. That is, there was a significant increase in protein production governed by various genes at increasing ages from 21 to 100 days."

These included proteins regulating cell proliferation and differentiation, including tumor-suppressing proteins and a large number of unknown proteins. The exception was decreased expression of the GAD1 gene. It encodes a key enzyme of the GABA-ergic system, which could be involved in hormonal regulation and breast cancer development. GAD1 has consistently been overexpressed in primary breast cancer.

"In contrast, the BBP exposure modified the genomic signature of the mammary gland primarily at 21 days of age and had less effect later," Moral said.

Future studies are needed to determine whether exposure to such xenoestrogens leads to breast cancer in rats and whether these estrogens bring about similar gene alterations in human breast tissue.